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Operation and Maintenance Manual PEM Fuel Cell Test Station

1. seen 36 Figure IV 13 Front Panel Additional Channels Display ssssssesessssesessssreesssesesssseee 37 Figure IV 14 Error Status display icles taie ie EE 38 Figure IV 15 Startup and Subtask Section of the Block Diagram 39 Figure IV 16 Display and Shutdown Section of the Block Diagram 4 Figure IV 17 Dialog for choosing a stack to test 44 Figure IV 18 Dialog for setting the stack parameters see 44 Figure IV 17 Data File Configuration Dialog cs tasa teo d oerte ee eate 49 Figure IV 18 Dialog for Selecting the Data File Contents eee 50 Figure IV 19 Modifying the IV Curve Graph seen 51 List of Tables Table IV 1 Air Subsystem Controls Indicators and Settings susuuss 23 Table IV 2 Hydrogen Subsystem Controls Indicators and Settings 24 Table IV 3 Cooling Subsystem Controls Indicators and Settings 26 Table IV a Puck Cell EE 28 Table IV 5 Safety Controls and Settings 04 5 einer te to tete thoai 29 Table 1V 6 Load Seis urere comidas ett da ti apad duo Pu Pede pera da od ets 30 Table TV 7 File ett 34 PADI ESV S EE 35 Table IV 9 Normal Values for Test Station Operating Variables 000 0sssseesssesessssee 46 Table V 1 Troubleshooting a Low Level Faute 56 Table V 2 Troubleshooting Fuel Cell Stack
2. Always assume a cylinder is pressurized handle it carefully and avoid bumping or dropping Never drop cylinders from trucks or any raised surface to the ground Lifting a cylinder requires two people Never lift a cylinder by the cylinder cap e Secure cylinders in suitable cradles or skid boxes before raising them with cranes fork trucks or hoists Do not use ropes or chain slings alone for this purpose Never use a gas cylinder as a roller for moving materials or for supporting other items Storage General Practices Cylinders are sometimes shipped tied horizontally on wooden pallets individually contained by saddle blocks and double banded to prevent rolling and sliding These are not recommended methods for cylinder storage Use the following guidelines for cylinder storage Store adequately secured cylinders upright on solid dry level footings preferably outside of occupied buildings and away from traffic lanes Shade cylinders stored in the sun during the summer whenever possible Store cylinders away from sources of intense heat furnaces steam lines radiators Do not stockpile gas beyond the amount required for immediate use Ensure that containers stored or used in public areas are protected against tampering and damage Furthermore containers stored inside or outside should not obstruct exit routes or other areas that are normally used or intended for the safe exit of people e Always store cylind
3. C Pulse Period sec Manual Fill Therm 4 C Reservoir Fill Time sec Therm 5 C Conductivity uS Flow rate L min Figure IV 4 contains a diagram of the COOLING controls indicators and settings COOLING Air Cooling Load Safety Water Circulation EE ed Pump Disabled 2 Teme Control Circulation Temperature Reservoir Set Point 50 deg C Auto Fil 3 High Dead Band Z des C EOSED Marua ri SZ deo C Low Dead Band Pulse Period 822 TFC C Them2 RSC Reservoir Therm 3 C Fil Time SR sec Therm 4 E Therm 5 C Ambient Temp Bn G Conductivity uS Flowrate L min Figure IV 4 Front Panel Cooling Controls Indicators and Settings The water circulation pump circulates water from the water reservoir through the heat exchanger to the fuel cell and back to the reservoir The water is heated or cooled to maintain a desired water temperature as measured by the fuel cell thermocouple TFC or any thermocouple connected to THERM 1 within the SET POINT temperature range TFC is located in the water manifold as water is leaving the power section and entering the humidification section Water heating is accomplished using cartridge heaters in the reservoir and heat tape on the tubing leaving the pump Cooling is achieved using fans mounted to the heat 26 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation exchanger The SET POINT temperature wi
4. Operations and Maintenance Manual Chapter V PEM Fuel Cell Test Station Troubleshooting compare that value to the value that should be sent based on the software logic and to the value actually being sent through the backplanes WARNING Before making significant changes to the hardware such as removing components that are believed to have failed always check that the instruments are powered up and that the proper signals are being sent to and from the instruments D Low Level Faults There are four low level software initiated faults low cell voltage operating temperature hydrogen pressure and water reservoir fill state All low level faults result in a software controlled shutdown that places the hardware in a safe state leaves the backplanes powered and keeps the test station program running Ifthe lowest cell voltage falls below the minimum cell voltage set in the Safety Settings a shutdown will occur and the ERROR STATUS will display a Low CELL VOLTAGE fault To determine why a particular cell voltage is performing poorly refer to the Fuel Cell Faults section of this chapter The operating temperature setpoint measured where cooling water leaves the power section is set in the COOLING SETTINGS The temperature at which a fault occurs is set in the SAFETY SETTINGS If the operating temperature exceeds the fault temperature setpoint a low level fault occurs The hydrogen pressure must always be within the range sele
5. 175 150 125 100 o m amp cm mwem Stack Output Voltage Current Power EN v 8 NN Ave Cell V E mv Stack History bs total hours of operation HEU total amp hours produced Scan Rate Mode Slow Fast Figure IV 5 Front Panel Fuel Cell Indicators Individual cells or cell blocks are monitored with up to 32 voltage taps Vtaps If for example a 60 cell stack were monitored 30 voltage taps could be placed on every other 28 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation cell such that each tap monitored the total voltage across a pair of adjacent cells The VTap displays on the front panel would indicate the average cell voltages for each 2 cell block being monitored The total stack VOLTAGE CURRENT and POWER are also displayed along with the stack CURRENT DENSITY and POWER DENSITY Under STACK HISTORY the fuel cell hour counter TOTAL HOURS OF OPERATION displays the number of hours the stack has run at a current greater than 0 3 Amps The fuel cell amp hour counter TOTAL AMP HOURS PRODUCED displays the cumulative number of amp hours the stack has produced also at a current greater than 0 3 Amps These counters can be reset when a new fuel cell stack is installed on the test station Located at the bottom of the FUEL CELL indicators box is a toggle control used to manipulate the data acquisition scan rate The graphics used to display data to th
6. Air Subsystem and Settings Table IV 1 lists the controls indicators and settings for the air subsystem 22 e Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Table IV 1 Air Subsystem Controls Indicators and Settings Controls Indicators Settings e Air Supply Setpoint Air Stoichiometry Air Source Blower or MFC e Ar Surge Actual Air Stoichiometry 96 MFC Calibration Airflow slm Blower Airflow Sensor Calibration Air Inlet Pressure in H20 Airflow Mode Fixed or Stoichiometric Fixed Flow slm Minimum Stoich Flow 96 Setpoint Stoichiometry Surge Factor x flow Figure IV 2 contains a diagram of the AIR controls indicators and settings There are two possible sources of air for the test station a blower or a mass flow controller MFC An MFC requires a supply of compressed air for controlling airflow The desired AIR SOURCE is selected using the left set of tabs in the AIR settings tab control Calibrations necessary for using either a blower or an MFC are included in the selected AIR SOURCE frame The AIR SOURCE and associated calibrations should not be changed while the program is running WARNING Changing the MFC or BLOWER calibrations while the program is running may damage the fuel cell The program responds instantaneously to changes in the calibration curve formula Since only one variable in the formula can be entered at a
7. Pressure Relief Device Standards Part 3 Stationary Storage Containers for Compressed Gases CGA G 5 5 Hydrogen Vent Systems CGA P 1 Safe Handling of Compressed Gases in Containers National Fire Protection Association NFPA 50A Standard for Gaseous Hydrogen Systems at Consumer Sites 82 Operations and Maintenance Manual Appendix A PEM Fuel Cell Test Station System Specifications and Drawings Appendix A System Specifications and Drawings Operations and Maintenance Manual Appendix A PEM Fuel Cell Test Station System Specifications and Drawings SCHATZ ENERGY ifi i EHE Ma Specifications CENTER Fuel Cell Test Station ANN Stack Specifications Maximum number of cells 32 Power rating 4 kW Maximum current 180 Amps Fuel System Pressure regulation manual pressure regulator 0 10 psig Automatic manual fuel gas purge Programmable time interval Air System Air mass flow controlled with range switching 0 200 slm 1 0 slm Less than 2 sec Wake up response Stoichiometrically load following Blower controlled 0 200 slm Stoichiometry software controlled 0 60096 DI Water Cooling System Heater 400 watts Cooling fan heat exchanger 4 slm water flow 2 5 kW heat removal Automatically manually filled DI reservoir Software controlled stack temperature Manually controlled water flow Computer Control Signal conditioning 5B backplane hardware Data acquisition PCI DAQ boards Software LabVIEW 6i Plat
8. Failures see 58 Table VI 1 Pressure Relief Valve SetDorntss oec ee tere oov agone te Oni eg 61 Table VII 1 Some Physical Properties of Hydrogen and Methane 70 vi Operations and Maintenance Manual PEM Fuel Cell Test Station List of Acronyms AC BP CGA DAQ DC DI DOT FC gpm H HO in WC LO IV lpm MEA MFC NFPA O2 PEM PRD PRV psi psig SERC sl slm SSR TFC UPS VAC VDC VTaps AP alternating current back pressure Compressed Gas Association data acquisition direct current deionized U S Department of Transportation fuel cell gallons per minute hydrogen water inches of water column input output current voltage as in IV curve or polarization curve for a fuel cell liters per minute membrane electrode assembly mass flow controller National Fire Protection Association oxygen gas proton exchange membrane pressure relief device pressure relief valve pounds per square inch pounds per square inch gauge Schatz Energy Research Center standard liter at 0 C 1 atm standard liters per minute solid state relay fuel cell operating temperature uninterruptible power supply voltage volts alternating current volts direct current custom cell voltage probes microsiemens pressure differential vii e Operations and Maintenance Manual PEM Fuel Cell Test Station Preface This manual was prepared by Schatz Energy Research Center SERC s
9. Fuel Cell Test Station uijs S WAM UOTIS Tal 9UIEN AR Hed Y Auen NN 20 11 6 Ita uewideys Sap guung ZivHos BS 2011 IG prouos EIN OCH 0CL NLA PY aunssaiq MO JI2AQ our uei or SZ I A ueq JI0AJaS2 dung uornp no35 uis uorng n3Jt 13M uongjs eat EL Jll sr or 0 Id iosuaS AyAtjonpuo wdi c z70 DPN MOT Je8ueugax WH eder SA PA Susan ayo Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station g 0otstAant auou 9 e3g H3lN39 pouryaeg juoa Ava Ajayeg WEN AN HOuv3s3u ASH3N3 N Z0 L1 L0 eq p3ug y Ag uae ZIVHOS EF Joued xoeg Cem oq 2341 0a LN3A OvAOZL avol 71149 7304 B HOLOV 1NOS 24 9a U au LU iOVA0ZL B SSVdAS DOGHOLYM 2q H 1eMog suejdyoerg xt Q f1 ssed g wa xt SE WHEY exouis xit O eiqeua Josues ZH Mayes smes ees O uas j jaued Ajejes euejdxyoeg spued Peg pue yuo nose L Ajayeg uesior Jo Am oprm Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station pourSutuM vag Apes awen al H98v393H W A9U3N3 N Z0 TE L0 23eq pau r Ag uaedq ZIVHOS Sup Agi ayes UESN Jo Am DLL JORUN S Asejuawoyy ssed g uang US pue C Jejnduuo2 uelis SjeAgoeag peo meg kepy FE EL oiuonoe 3 Buiyoye E ayenjoy X uueje uo uedo s et uue v SION g dV SUE J0sua
10. TYPE could be set to limit MAXIMUM POWER Figure IV 8 displays the LOAD SETTINGS tab control when the load is being pulsed The RUN button is used to start the series of pulses When the pulsing is finished the RUN button will return to the OFF state If the value of any parameter changes the software 31 o Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation will detect a change and will send an update of all values to the load The FREQUENCY DUTY CYCLE or the BASELINE us and INCREMENT us values set the frequency at which the pulses occur and the length of time that the pulse remains high The BASELINE value is used to set the bottom of the pulse and the sum of the BASELINE and the INCREMENT set the value of the top of the pulse Either the voltage current or power can be controlled during pulsing depending upon the MODE selected The NUMBER OF PULSES control is used to set the number of pulses that will occur after the RUN button is set to the ON state The SLEW RATE us and SLEW MODE are additional controls used to manipulate the length of time that pulses occur and the transition times when pulsing For a detailed description of these controls refer to the Electronic Load Operation Programming Manual in Appendix B Cooling Load Safety Enable Load Range MIR Resa eee Mode K RELAT nsu Constant Pulsing IV Curve Driving Cycle Baseline V A W Sun Incre
11. To ensure that all transducers are properly maintained and calibrated follow the specifications given for each instrument in the manufacturer s literature D Control and Monitoring Hardware The control and monitoring hardware should not require special procedures for maintenance To ensure that the equipment functions properly use the following guideline 1 Check Integrity and Condition of Visible Wiring Periodically a visual inspection should be made of any electrical wiring that can be easily accessed Check for damage to wire insulation and gently tug on the wires to make sure they are not loose 2 Keep Components Clean Periodically all easily accessed electrical components should be inspected and cleaned as needed Do not allow dirt dust and debris to accumulate around electrical components Vacuum these areas as needed 66 Operations and Maintenance Manual Chapter VI PEM Fuel Cell Test Station System Maintenance 3 Uninterruptible Power Supply UPS The UPS unit will normally require no special maintenance However if for any reason it is taken out of service for an extended period it should be stored unplugged During out of service storage the UPS should be plugged in once every three months and allowed to recharge for 4 to 6 hours to maintain the batteries charge elasticity See page 7 in Tripp Lite UPS owner s manual Note that to avoid a safety shutdown the SERC electrical control panel should remain p
12. Water Supply The test station user must provide a filtration system that delivers DI water to the test bench The water must be particle free and have a conductivity of 5 uS or better The supply line is connected to a blue handled manual valve at the back top center of the test station Water drains from the system via a valve located under the water reservoir and is directed into the fuel trench in the floor 11 e Operations and Maintenance Manual Chapter II PEM Fuel Cell Test Station System Requirements 4 Water Drainage Three water drain hoses leave the backside of the test station and are directed into the fuel trench These hoses include the fuel cell air exhaust line the purge drum manual drain line and a combined water reservoir manual drain and overflow drain line 5 Power Supply Power is provided to the test bench from a 30A 120 VAC circuit hardwired into the junction box adjacent to the electrical panel on the wall behind the test station B Fuel Cell Requirements To safely operate the fuel cell stack provided adhere to the following recommendations IMPORTANT Operate the stack at steady state temperature at least once a month This will maintain hydration of the stack s membrane electrode assemblies MEAs which may significantly extend stack lifetime 1 Air Supply e Air inlet pressure is dependent on the airflow When at high flow rates monitor inlet pressure closely to ensure pressure does not excee
13. are particularly critical and could result in serious personal injury and or damage to the test station 1f performed incorrectly These procedures are marked with an exclamation mark in the margin as shown at left and are marked Warning Caution Important or Note Vill Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description Chapter I Test Station Description The purpose of this chapter is to provide an overview of the PEM Fuel Cell Test Station hereinafter simply referred to as the test station and its major components The test station is designed to allow researchers to test and evaluate proton exchange membrane PEM fuel cell stacks SERC has provided a 24 cell 300 cm PEM fuel cell stack along with the test station A photo of the system showing placement of major components is shown in Figure I 1 The Test Station consists of seven integrated systems all mounted on a standard workbench and an attached Superstrut frame The systems include Load Safety Electronics and UPS Computer Figure I 1 Photo of Test Station Showing Major Components e Air System The oxygen in air acts as a reactant with the hydrogen in the fuel cell producing water and releasing electrical energy This system provides air from a blower or mass flow controller to the stack Hydrogen System Hydrogen is the fuel that powers PEM fuel cells The hydrogen system stores hydrogen in h
14. gas if at all possible This is the top priority To do this shut down the fuel cell test station by pushing the emergency shutdown button on the front panel 78 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety of the safety tray in the electronics cabinet or by tripping the circuit breaker that provides test station power at the main electrical panel whichever is safer An emergency shutdown will close all solenoid valves and shutoff power to all components except the control computer and the electronic load This will slow and eventually stop the leak unless the gas is coming from upstream of the solenoid valve If the leak is from upstream of the solenoid valve and it is safe to do so close the cylinder valve to stop the gas flow Shut off all electrical power to the test station UPS and surrounding areas by tripping the circuit breakers in the main electrical panel Note Electrical power to the control computer and the electronic load cannot be easily shut off because it is supplied via the UPS e Approach the fire from an upwind position as the flame can flash downwind very easily e Extinguish the fire by aiming the fire extinguisher hose at the base of the fire squeezing the handle and sweeping the hose back and forth e Ifnecessary allow the fire to burn itself out This should happen quickly if the flow of hydrogen is stopped as hydrogen disperses rapidly e Provided all electrical power
15. on particular electrical components Before performing maintenance on or near any electrical components the technician should check for high voltages on electrical circuits using a voltmeter Water and electricity are both present on the fuel cell test station Together water and electricity can be a deadly combination System operators must use special caution when 79 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety working at the test station if water or other liquids have been spilled or have leaked in the vicinity of the test station Note Only authorized trained personnel should work with the fuel cell test station electrical system RESPONSE If a person receives an electric shock take the following steps 1 Do not touch the victim if there is any possibility that they are still in contact with a live electrical circuit 2 If necessary use a plastic or wooden implement such as a broomstick something that is NOT electrically conductive to push the victim away from the live electrical circuit 3 Once the victim is safely separated from the electrical circuit check for breathing and a pulse If the victim is not breathing administer rescue breathing If the victim does not have a pulse administer cardiopulmonary resuscitation CPR Call 911 Keep the victim warm The victim should not eat or drink until he or she has been seen by a doctor Soy A If an electrical shock hazard
16. operate pneumatic tools or dust clothing Remember oxygen is not a substitute for compressed air Do not use vendor owned cylinders for purposes other than as a source of gas These cylinders may only be pressurized by the owner e Do not strike a welding arc on a cylinder 74 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety Before using equipment regulators pressure gauges gas hoses etc in a pressurized gas system make sure that the equipment is adequately rated to meet system pressure requirements Operation e After installing the regulator and before opening the cylinder valve fully release turning counterclockwise the regulator pressure adjusting screw e Open the cylinder valve slowly Never use a wrench on a cylinder valve that will not rotate manually Stand clear of pressure gauge faces when opening a cylinder valve Keep removable keys or handles in place on valve spindles or stems while the cylinders are in service e Never leave pressure on a hose or line that is not being used To shut down a system close the cylinder valve and vent the pressure from the entire system Empty Cylinders Leave some positive pressure a minimum of 20 psig in empty cylinders to prevent suck back and contamination Close the valves on empty cylinders to prevent internal contamination remove the regulators and replace the protective cap e Usea cylinder status tag to indicate wheth
17. station is operating Only authorized trained personnel should operate the fuel cell test station B Test Station Safety Features The fuel cell test station is equipped with numerous safety features to ensure safe system operation These features include smoke alarms hydrogen gas alarm ventilation flow alarm watchdog timer pressure relief devices emergency shutdown button and intrinsic safety features i e if electrical power is lost all relays solenoid valves and power contactors will revert to a safe condition Selected safety features are discussed below Hardware and software safety features including high level and low level system shutdowns are also discussed in the Safety Control System section of Chapter I and in Chapter V Troubleshooting Smoke Alarms Smoke alarms are mounted in the vent hood and on the wall of the test station room They are AC powered with an internal battery backup If an alarm is set off they will give off both audible and visual alarm signals and will initiate a high level emergency shutdown of the fuel cell test station The smoke alarm is discussed further in Chapter V Troubleshooting 68 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety Hydrogen Gas Alarm A hydrogen gas detector is located in the vent hood of the fuel cell test station If hydrogen gas is detected at a concentration of 1 by volume or more 25 of the lower flammable limit of hydrogen i
18. time the airflow might be much greater than intended for brief periods during formula entry AIR i Cooling Load File Safety Test onsen Air Supply Air Source Air Flow Mode lor Surge MFC Blower Stoichiometric Fixed l Stoichiometric Flow MFC Calibration Stoichiometery A voltszairslm m b Set Point o Minimum Flow ZER sim Actual D set point Zb Air Flow RES sim 1 Air Surge Factor Ni Air Pressure BR Min WC Weg m x fo Figure IV 2 Front Panel Air Controls Indicators and Settings In addition to the two possible sources of air there are two different airflow modes stoichiometric and fixed The AIRFLOW MODE is selected using the right hand set of tabs 23 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation in the AIR settings tab control If FIXED flow is chosen the operator can set a constant airflow rate If STOICHIOMETRIC flow is selected the operator can set a minimum flow rate and a setpoint or target stoichiometry The stoichiometric flow delivered to the stack is dependent upon the setpoint stoichiometry the number of cells in the stack and the amount of current drawn from the stack as described by fios 0016s gt J I N cell Amp 100 Where S Air stoichiometry I Stack current Amps N Number of cells in stack In the STOICHIOMETRIC airflow mode the greater of either the minimum flow or the stoichiometr
19. to deliver gas at pressures ranging from 0 5 to 5 0 psig The hydrogen fuel cell pressure is nominally 3 0 psig The regulator can be adjusted during fuel cell operation preferred or while shut down If adjusted during operation make small changes and allow time for the regulator to respond and prevent a pressure surge When the regulator is adjusted while shut down the hydrogen supply solenoid valve must be open to provide pressure indication pressure gauge and pressure transducer and gas must flow through the regulator A pressure relief valve is built into the regulator and has a non adjustable relief setpoint at 9 psig WARNING Note that the built in relief valve relieves gas into the housing where the adjustment screw is located If the relief valve lifts with the access plug out or loose hydrogen will vent into the atmosphere through the open port and not through its designated vent line Be sure the access plug is tight when pressure adjustment is complete The low pressure hydrogen regulator adjustment procedure is as follows 1 Remove the black plastic access plug by turning counter clockwise 16 Operations and Maintenance Manual Chapter III PEM Fuel Cell Test Station Test Station Hardware Operation 2 C Using a flat bladed screwdriver turn the adjustment screw to change the delivery setpoint Turn the nut clockwise to increase the pressure and turn counter clockwise to decrease the pressure Once the desired press
20. to the data file Bad 44 a Operations and Maintenance Manual Chapter IV PEM 6 Fuel Cell Test Station Test Station Software Operation data results because the backplanes are unpowered and data is being written to the data file the subtask section of the block diagram is iterating The ERROR STATUS text box will indicate the last fault that occurred usually a Manual Shutdown Clear the software safeties by pressing the CLEAR SAFETY FAULT button in software WARNING A clear distinction should be made between the SAFETY ENABLE button on the Safety Tray Panel the SAFETY ENABLE button in software and the CLEAR SAFETY FAULT button in software The Safety Tray SAFETY ENABLE is used to clear high level hardware faults and is a physical button The SAFETY ENABLE button in software is used tell the software that you want to safely shut the system down when a low level software fault occurs The CLEAR SAFETY FAULT button is a software control and is only displayed after a low level fault occurs Enter the desired temperature and reservoir values in the COOLING settings box Enable the reservoir AUTO FILL to fill the water system Once the reservoir and system has completed filling turn the water pump on Monitor flow rate and adjust the water throttle valve as necessary Open and leave open the air bleed valve on the right endplate to remove trapped air from the cooling manifold 10 Enable temperature control by pressing the T
21. vis GlobalDIO_FCTS vi i Last modified on 7 16 02 at 4 00 PM Printed on 8 2 02 at 10 26 AM Port 0 Input S Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station FUON cO TE L ayeg Hed pna SEIT pneyxy Qurodiss OTH 0S 1D Add 1oonpsueir amnssaid HIN uejsAS fy UOTIeIS Sai UmN AW Ge V AS9H3N3 N uewdeyo 5 Agqumeig ZIVHOS S urs 007 0 sajou DIEI ng amssald S uauluio weqskS ATY UOCTIeIS Ise ML autodias Sisd cc Ad SATA plougos Addng Jo1e n32 amssaiq JOSsaduroz iry wog Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station 9 UOISIA9ST Uess ushorpAH uor393s sei WEN AR 0 I1 6 9 eq ueudeuj 9 vgumeig WIP DIBA aae A ssedig AJLA prouspos aang ND IPD PA u3iN39 AE HOuV3s3u AOH3N3 NN y E ZLVHOS juaw W93S S u oIp H4 uot eS AseL ML aea ls 001 0 prouqog PN Gisd 6 Ajddng mofa MARA JAPI DEI p SSL JOVRINSIY amssa4g MO anen 1aohpsuerp uoau OH amnssoid anssad JOUET MLA jenueyy isd ost ALA amp ddns PAY ounssatg DARA 102A U I U H I I 1 I I I 1 1 H 1 I U I a8ner A d Ta Q Jo ngo enssotq um Wee we wee SA EA Japuy Ad 1opuj 4j uo304p H DUI UDA dur 1u2A Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM
22. 2 Pressure Relief Devices The subsystem pressure relief devices PRDs are checked to assure the setpoints are maintained and the valves have not become stuck in their normally closed position As listed in Table VI 1 there are five spring loaded PRDs four of which require checking the hydrogen medium pressure the air medium and low pressure and the water low pressure relief valves The hydrogen low pressure relief valve is not adjustable and does not require checking The maintenance interval for setpoint checks is once a year Table VI 1 Pressure Relief Valve Setpoints ow mmm 5 mr x Cp ewe 8 DNO ooo we ewe ON RNC SS A pressure test rig which includes a compressed gas cylinder cylinder regulator and hose a pressure gauge with the appropriate pressure range and a vent valve is required to test the PRDs The test station must be shutdown and the systems depressurized or drained The PRDs should be removed from test station The General Pressure Relief Valve Procedure outlines the necessary steps to complete the task 61 Operations and Maintenance Manual Chapter VI PEM Fuel Cell Test Station System Maintenance General PRD testing procedure 1 Close the system isolation valve for the appropriate subsystem 2 Depressurize or drain the system until pressure indicates 0 psig where the PRD is installed 3 Remove the tee that houses the relief valve from the system by loosening the Swagelok fittings each sid
23. 308 316 321 347 copper and its alloys such as brass bronze and copper nickel and aluminum and its alloys Non metallic materials that can be used in gaseous hydrogen service for valve seats gaskets etc include Buna N Viton Kel F and Teflon Physiological Hazards Hydrogen is non toxic but it can cause asphyxiation in a confined area due to displacement of oxygen Smoke inhalation a primary cause of injury due to fires is considered less serious in the case of hydrogen because the sole product of combustion is water However secondary fires can cause smoke and other combustion products that present a health hazard 2 Handling Compressed Gases The following information has been adapted from the Compressed Gas Association s pamphlet P 1 Safe Handling of Compressed Gases in Containers 2000 and Lawrence 72 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety Livermore National Laboratory s Environmental Safety and Health Manual Part 18 1 Pressure updated 2001 Note Only authorized trained personnel should work with compressed gases e Use a four wheel cylinder cart for moving gas cylinders These cylinders are difficult to move manually because of their shape smooth surface and weight Make sure that the protective valve cover is in place when a cylinder is not connected to a regulator or manifold Mark partially filled cylinders with the remaining product pressure
24. 5VDC Power Supply Instrument Pinouts and Color Codes Safety System Rack Mount Tray Chassis RM14212 ESL 320A 350 Series AC Powered Photoelectric Smoke Alarm Johnson Controls P32 Series Sensitive Differential Pressure Switch Bacharach Series 4600 Gas Plus Universal Gas Transmitter Brentek WDT 24D 5A Watchdog Timer Module Brentek DIN5 DIN Rail Mounted I O Sockets SafetyGram 4 Gaseous Hydrogen Information Operations and Maintenance Manual Appendix C PEM Fuel Cell Test Station Quick Reference Procedures Appendix C Quick Reference Procedures Operations and Maintenance Manual Appendix C PEM Fuel Cell Test Station Quick Reference Procedures Quick Reference Procedures Start Up Procedure Oy a Gt 19 20 21 22 23 24 Turn the UPS on Turn the Safety Tray POWER switch ON Press the SAFETY ENABLE button on the tray Turn on the computer and launch the LabVIEW test station program Connect all subsystem lines electrical cables VTaps and thermocouples Perform a valve line up on the test station subsystems as follows a Water Circulation System i Close the water reservoir drain valve ii Open the DI water supply valves iii Open the water throttle valve half way b Air System i Open the air supply valve ii Position the 3 way valve to the desired MFC c Hydrogen System i Close the vent valve supply manual valve delivery valve cylinder valve and purge drum Back out the regulator ii Vent back to the cylinder
25. Cell Test Station System Specifications and Drawings University of Michigan IO List Physical Sensor Excitation Channel Type Global Variable Range Output Voltage Excitation Subsystem Current Hardware 33 NA NA 35 AI 0 200 deg CINA NA 0 200 deg C 38 IFC 0 40 Amps IFC QH20 Q Lmin ua Bon meter H20 Cond I0u i20mA 1236V 30mA Conductivity meter Hydrogen gl om jo 100sim osy 4 215 V Air 43 200 mA PH2 3 mA Air PAir O Spsig av 13 30V Press Transducer _ Safety Lat _ aP in room safety psig junknownunknown _ unknown dP Transducer 47 thr ilat Spare EE iir cs pec AO NA Air HAO OurBlwe o200sm 020m Blwe cuu Ao Eee E E LLL Cooling oo Reservoir Flo Swin Ia A pav FlaSwich LL Lim2lpt spare E DE EE EE e Safety 1 dog wachdogrme NA NA ax Watehdog Module Electrical 9 DO LoaiComaco NA NA Jav leontactor Hydrogen 10 DO H2SupplySolmid NA Ia av Air IL oo Air Supply Solenoid NA NA 24V 03A Solenoid Valve 24 V Solenoid Valve Hydrogen 13 bO H2PureSolnod NA INA pav 09A Solenoid Valve Cooling 14 DO Reservoir Fans 24 V 4 Fans Air Supply Solenoid NA 24 V Air 16 DO Blower Power INA wa 4v Blower AC Outlet Pum 120 VAC Cooling loo ACOwde2 ResHeaers NA Ia 120 VAC Cooling 19 DO ACOude3 Res Heaters 120 VAC
26. Cooling 20 DO_ AC Outlet 4 Heat Tape Ja 120VAC Daa LL 2i pbO JAC Outlet 5 Spare INA wa m2ovac SwithedOutet 22 po AC Outet 6 Spare NA INA ovac jSwithedOudet LD jacOuet7 Spre IA NA i21 vac Switched Outlet pT 24 ACOwet8 Sme NA NA awa Switched Outlet irato astra IDIOT ieee MS HENCE ERE Operations and Maintenance Manual Appendix A PEM Fuel Cell Test Station System Specifications and Drawings Page GlobalAl_FCTS vi 2 E Denise Projects Univ of Michigan Software SERC FC TS Global vis GlobalAl_FCTS vI Last modified on 7 9 02 at 2 32 PM Printed on 8 2 02 at 10 26 AM Serer III Operations and Maintenance Manual Appendix A PEM Fuel Cell Test Station System Specifications and Drawings Page GlobalAO FCIS vi 1 E Denisa Projects Univ of Michigan Software SERC FC TS Global vis GlobalAO_FCTS vi Last modified on 7 9 02 at 2 4 PM Printed on 8 2 02 at 10 26 AM Operations and Maintenance Manual Appendix A PEM Fuel Cell Test Station System Specifications and Drawings Poge 1 GlobalCD FCTS vi A E Denise Projects Univ of Michigan Software SERC FC TS Global vis GlobalCD_FCTS vi Last modified on 6 17 02 at 3 30 PM Printed on 8 2 02 at 10 26 AM Operations and Maintenance Manual Appendix A PEM Fuel Cell Test Station System Specifications and Drawings Page 1 t GlobalDIO_FCTS vi zia E Denise Projects Univ of Michigani Software SERC FC TS Global
27. EMPERATURE CONTROL button 11 With the air inlet hose disconnected from the stack select the AIR settings box and enter air source airflow mode and surge information Open the AIR SUPPLY and monitor airflow and inlet pressure to ensure the desired flow rate is achieved and pressure is low Re connect the air inlet hose 12 Enter purge control values in the H2 SETTINGS box Open the H2 SUPPLY and 13 monitor hydrogen pressure Refer to the Low Pressure Regulator Adjustment procedure in Chapter III if the pressure is not within desired range Manually purge the fuel cell by pressing and holding open the PURGE button for a few seconds Cell or block voltages should increase to 800 950 mV per cell 14 Select the SAFETY settings box and enable and enter values for the low level 15 faults Once voltages are above the minimum cell voltage safety setpoint enable the SAFETIES 16 Turn on the load 17 Enter the correct range desired mode and limit type and value information in the LOAD SETTINGS box 18 Press the ENABLE LOAD button 45 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation 19 Increase the load by entering the desired value into the SETPOINT control box Cell voltages will decrease as the load on the fuel cell stack is increased 20 Refer to Table IV 9 to verify the system parameters are within their normal range of operation Table IV 9 No
28. Operation and Maintenance Manual PEM Fuel Cell Test Station zem SA Wi ji EUM o Re an we Ea September 2002 Prepared by Schatz Energy Research Center Humboldt State University Arcata California S SCHATZ N ENERGY UN RESEARCH CENTER K 20 Operations and Maintenance Manual PEM Fuel Cell Test Station Foreword The Schatz Energy Research Center Schatz or SERC provides this manual to assist researchers in the operation and maintenance of the Schatz PEM Fuel Cell Test Station System operators should read this manual carefully with special attention to the chapter on safety before operating or performing maintenance on any part of the test station This manual is not intended to provide complete operating instructions for the system Operators should also read the component operating manuals found in the binder that makes up Appendix B of this manual and complete the system operator training session before running the system The system should only be operated by adequately trained authorized personnel SERC assumes no liability for any harm or injury resulting from the proper or improper use of the fuel cell test station or this manual In the event that test station users encounter a problem with the test station they are unable to resolve using this manual and the test station component manuals they should shut down the test station and contact Schatz staff immediately by phoning 707 826 4345 faxing a d
29. RAM SHUTDOWN button 46 e o e Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation 2 Afew seconds after the PROGRAM SHUTDOWN button is pressed check to make sure that the BACKPLANE POWER LED on the Safety Tray front panel is red 3 Turn off the load Test Station Power Down 1 When finished testing press the software PROGRAM SHUTDOWN button 2 Afew seconds after the Program Shutdown button is pressed check to make sure that the BACKPLANE POWER LED on the Safety Tray front panel is red 3 Close the LabVIEW program and turn off the computer and monitor 4 Place the POWER switch on the front panel of the Safety Tray into the OFF position 5 Turn off the UPS 6 Close the hydrogen cylinder valve and hydrogen supply valve WARNING Although the UPS has been turned off the UPS has battery backup and may still supply AC Read the UPS manual thoroughly when any maintenance is completed on the UPS or the AC lines it supplies C Modifying Software Depending upon the type of tests to be conducted the software may need to be manipulated The following sections outline procedures for modifying software due to typical hardware changes WARNING Any person wishing to modify the software should first complete the tutorials included with the LabVIEW software and user manual and feel comfortable programming with a graphical user interface WARNING Be sure tha
30. RRAY CHANNEL column enter the channel number corresponding to the thermocouple port that the thermocouple is plugged into The thermocouple data is stored in the ANALOG INPUT array so the ARRAY direction should be pointed to ANALOG INPUT Finally the threshold say 1 C is entered With this information selected the data file should contain the stack comments followed by the column headers The first and second columns of data will contain the time of day that the data were recorded to the data file The next columns will contain the cell voltage data The data chosen in the contents dialog will follow the cell voltages 49 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Change the variables written to the Data File Do not include Time and the VTaps Array Calc Analog File Write Column Headers Channel H Data Input Threshold ch e COOC ETE TFC C Therm 2 C m T Ambient C H2 Pressure psig Air Pressure in H2 Flow slm Airflow slm IFC amp mps Current Density Power Density FC Hours FC Amp Hours e D Figure IV 18 Dialog for Selecting the Data File Contents iue isie COR Laie COR 0f Lale Lale Lale Lale Lale Laie Laie Laie Laie Lale Lale TERCERA Laik Laik Lie Lie Ls Lie Laik Ladik Ce CT Laie Laie Laie Laie Laie Laie Lale When the file contents are set press the DONE button 4 Connecting a New Transducer To add a new tra
31. Regulator set too Compare the low pressure Pressure high regulator setpoint pressure to the Maximum hydrogen pressure Safety Setting and adjust the delivery pressure if necessary Transducer value incorrect Make sure the analog input signal is being read in and scaled properly Low Hydrogen Empty Cylinder Check the cylinder pressure Pressure and exchange if pressure 100 psig Ifthe cylinder pressure is above 100 psig but the delivery pressure is below 30 psig increase the cylinder delivery pressure to 60 psig HYDROGEN SUPPLY SOLENOID Open the HYDROGEN SUPPLY Closed SOLENOID Toggle the HYDROGEN SUPPLY SOLENOID for proper response 56 Operations and Maintenance Manual Chapter V PEM Fuel Cell Test Station Troubleshooting Transducer value incorrect Make sure the analog input signal is being read in and scaled properly High water Poor supply water quality Check the water quality of the conductivity water being supplied to the test station and correct any problems Conductivity indication gt 10 Drain and refill water system Us on front panel Replace deionization cartridge according to maintenance procedure Reservoir Fill Reservoir filling too often Check for water leaks and ensure the reservoir drain valve is closed Check the fuel cell air inlet line between the pressure transducer and the stack If this line is full of water there may be a cross leak in t
32. Value SEONI Figure IV 7 Front Panel Load Settings The ENABLE LOAD button is used to control the fuel cell contactor located in the safety tray and also the contactor contained within the load itself When the load is enabled both contactors are closed and when the load is disabled both contactors are open The load has three ranges low medium and high for the current and the voltage These are selectable using the RANGE control Refer to the Electronic Load Operation Programming Manual in Appendix B for details regarding these ranges There are also four main MODES that the load can operate in CONSTANT CURRENT CONSTANT VOLTAGE CONSTANT POWER and CONSTANT RESISTANCE The mode that the load runs in is set using the MODE control The second level tab control in the LOAD settings is used to set the limits and conditions under which the load operates Figure IV 7 above displays the LOAD settings during CONSTANT operation The SETPOINT control is used to set the fixed value either current voltage or power depending upon the MODE selected at which the load operates For example if the MODE is set to CONSTANT CURRENT and the SETPOINT is set to 20 the load will draw 20 Amps from the fuel cell The LIMIT TYPE and LIMIT VALUE are used to set an upper limit on either current voltage or power Note The MODE and the LIMIT TYPE do not have to be set for the same variable For example the MODE could be set to CONSTANT CURRENT and the LIMIT
33. agram for the test station software Find the area of the code in the display section that looks like the code shown in Figure IV 19 for the IV curve graph gt Fuel Cell Test Station vi wi Diagram File Edit Operate Tools Browse Window Help ell V SN Fuel Cell Current Density Figure IV 19 Modifying the IV Curve Graph 51 Operations and Maintenance Manual Chapter IV a PEM Fuel Cell Test Station Test Station Software Operation The first value supplied to the bundled cluster is the X value The second value supplied to the bundled cluster is the Y value Change the global variable references to the desired channels for both the X and Y variables Open the Front Panel of the test station software 5 Rename the x and y axes to reflect the new variable names Rescale the x and y axes as needed 52 Operations and Maintenance Manual Chapter V PEM Fuel Cell Test Station Troubleshooting Chapter V Troubleshooting The purpose of this chapter is to help test station users identify and correct common problems that may occur in using the test station A High Level Faults Any high level software independent fault from the hydrogen detector smoke alarms or ventilation flow transducer when triggered will cause a loss of 24VDC and 5VDC power Loss of power will result in all hardware being shut down and placed in a safe state The LEDs on the front panel of the Safety Tray indicate which fault
34. ain electrical panel TA Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety whichever is safer An emergency shutdown will close all solenoid valves and shut off power to all components except the control computer and the electronic load Note Electrical power to the control computer and the electronic load cannot be easily shut off because it is supplied via the UPS This will slow and eventually stop the leak unless the gas is coming from upstream of the solenoid valve If the leak is from upstream of the solenoid valve and it is safe to do so close the cylinder valve to stop the gas flow b Isolate the area to prevent personnel injury c Ifthe gas leak has been stopped and adjacent equipment or structures have caught on fire put out the fire using an extinguisher or call the fire department d Post warning signs and isolate the area until the high pressure or gas leak hazard has been resolved 2 Fire and Combustion Hazards Hydrogen gas constitutes the single greatest fire hazard on the fuel cell test station See Section A 2 of this chapter for a description of the basic properties of hydrogen gas Hydrogen gas under pressure as in this system can be a special fire hazard because pressurization allows the storage of large quantities of fuel in a relatively small space RESPONSE Hydrogen fires are nearly invisible especially during daylight hours If you have any suspicion that a hydrogen f
35. al signals are conditioned using an SSR backplane with optically isolated solid state relay modules and a third DAQ board in the computer Figure I 6 shows the monitoring and control Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description hardware mounted to the DAQ panel with the labels and dashed lines indicating groupings of major components iiec a ro NNN E WER SUPPLIES T med i k D Tu 7 x ben emm mmm mmm mmm mmm mmm Figure Lo DAQ Panel The electronic load is controlled using an IEEE 488 2 GPIB controller board in the computer and a LabVIEW driver provided by DynaLoad F Test Station Software LabVIEW produced by National Instruments Corporation is the programming language used to write the software that controls and monitors the test station In order to operate maintain and modify the test station software it is necessary to have some understanding of the LabVIEW programming environment LabVIEW programmers interact with two different interfaces namely the front panel and the block diagram The front panel is the operator interface used to control and monitor the test station A hardware state configurable parameter or safety condition can be manipulated using the controls on the front panel and physical phenomena are measured and displayed using indicators and graphs on the front panel The controls and indicators are organ
36. alf hour Inspection Inspect hoses and manifolds frequently and replace worn hoses and connections e Report leaking cylinders that contain hazardous materials to the appropriate safety officer Evacuate the area until the emergency response team arrives e Contact your appropriate safety officer before handling faulty or corroded cylinders these cylinders should be segregated CAUTION Only the vendor should alter or repair cylinders or cylinder valves General Precautions e Secure both ends of gas hoses with a hose restraint to prevent whipping in the event the hose or fitting fails For systems in occupied areas support and secure the hose and tubing at least every 7 ft Do not use an open flame to leak check a gas cylinder use soapsuds or a leak detection solution Remove the talc and dust from a new hose before connecting it e Do not use white lead oil grease or any other non approved joint compound to seal the fittings on an oxygen system a fire or an explosion could occur if oxygen contacts such materials Threaded connections in oxygen piping should be sealed with solder glycerin or other sealants approved for oxygen service Gaskets should be made of noncombustible materials e Never interchange regulators and hose lines with one type of gas for another Explosions can occur if flammable gases or organic materials come in contact with oxidizers e g oxygen under pressure Never use oxygen to purge lines
37. ammed in software to monitor individual cells or blocks of cells For individual cells place one VTap in consecutive order on every graphite tab For cell blocks place each VTap on the corresponding graphite tab for that cell block For example for monitoring blocks of 2 cells VTaps will be placed on every other graphite tab Figure III 3 shows the Vtaps connected to the rear of an eight cell fuel cell stack 15 o o Operations and Maintenance Manual Chapter III PEM Fuel Cell Test Station Test Station Hardware Operation TS ET Figure III 3 Rear View of Stack Showing VTaps To monitor temperatures inside the stack thermocouples are placed into the desired stack manifolds and connected to the DAQ system via the electrical panel The fuel cell operating temperature TFC is monitored in the water manifold as water leaves the power section the hottest accessible place in the stack The TFC thermocouple is placed in the fitting located in the top left corner of the left endplate below the hydrogen inlet fitting Additional fittings must be purchased to monitor temperatures at other points in the stack WARNING When placing a thermocouple into the power section of the stack the thermocouple must be electrically insulated Should a bare thermocouple come in contact with two or more of the graphite plates an electrical short will occur B Low Pressure Regulator Adjustment The hydrogen low pressure regulator can be adjusted
38. anual Chapter VII PEM Fuel Cell Test Station Safety Tagout Lockout Procedure When any component on the fuel cell test station is being serviced or repaired operators must use the following tagout or lockout procedures to ensure personnel safety and avoid accidental restarting of equipment during service procedures The purpose of a tagout is to provide clear notification to all personnel that the system or a system component is being serviced and must not be operated A lockout s purpose is to physically prevent operators or anyone else from starting the system or system component while it is being serviced Devices used for tagout lockout must meet requirements found in 29 CFR 1910 147 The Control of Hazardous Energy Lockout Tagout and 29 CFR 1910 333 Selection and Use of Work Practices Electrical Safety Related Work Practices If a piece of equipment is tagged out but not locked out one additional safety anti start measure must be employed such as opening of a circuit disconnect or physical blocking of mechanical equipment All new or temporary operators or operator s assistants must be shown these lockout tagout procedures before working with the fuel cell test station e Notify all personnel who operate or work in the vicinity of the equipment that a tagout or lockout is being implemented and which piece or pieces of equipment will be affected Make sure that the person performing the tagout or lockout is familiar with the equipm
39. atch the status of the safeties If any high level safety fault occurs the SAFETY STATUS LED will remain red and the 15A circuit will remain disconnected until the Safety Enable button is pressed The final LED indicator is the BACKPLANE POWER LED It is green when 5VDC power is being supplied to the backplanes Three control buttons are located on the left side of the front panel The red BACKPLANE START button is used to bypass the watchdog timer and supply 5VDC to the backplanes at startup Review the Safety Control System section of Chapter I for a review of the safety system The SAFETY ENABLE button is used to unlatch a safety fault When a high level fault occurs an alarm sounds and continues to sound until the SAFETY ENABLE button is pressed Alternatively the SIREN BYPASS button can be pressed to silence the siren after a fault For a detailed description of the operation of the Safety Tray during system startup refer to the Software Startup and Shutdown section of Chapter IV Power supplied to the electronic load and to the control computer and computer monitor are supplied via circuit 2 on the UPS 15A 120V AC This power is not switched off under any safety condition Power will continue to be supplied to these components from the UPS even if the AC input power to the UPS is disconnected e g at the main electric service panel 20 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Softwa
40. ay HO123NNOO agy HOIO3NNO2 Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station g uorsrAoT 70 20 80 21p0 ssum uade BULIM qoje 4jajes uesimory Jo AUN RL axouis GEI zH iie NIG 39 2GA ZL O jaued eg uo X310 s10128uuo Ou Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station UOISIASY UWALNIA y iguau muen ona Houvasay ADNANA N ZOLEE 33da Aeyow 0 4g gan ZLVHOS RS uiejs s OYA ueBiuoiw Jo N ML p aonad gld9 I9d peog no yesig LL aanaq sjeuueyD z uejdyoeg d d O sieuueu euejdyoeg Eu 89 H2S 129 I2d seue dyoeg jeuueu zZ pods 9 8y SjauueYO p euejdyoeg Lv ce sjauueyD eue dxyoeg Jeidepy aiqeo L 91 Sjeuueu z eue dyoeg 9502 9S SL 0 sjauueyD eue dxyoeg z Soine alemMyos 3 L 09 I9d AAZIAOET pue sieAup OVGIN WWM Od seupjdyoeg Jeuueu 91 Logs peje oepuf uod indinQ OWA Z uod eot eg indino 2GA L uod Indul 90A 0 uod sjeuueuo OO 10 q 8 se peinBijuoo uod yeg sjauueyo Jeppa ZE xoeH HSS Operations and Maintenance Manual Appendix B PEM Fuel Cell Test Station Component Manuals and Spec Sheets Appendix B Component Specification Sheets and Manuals see Separate Binder Components are listed in the order product literature is filed in the Component Binder Hydrogen System Hastings HFM 201 Flow
41. ber of seconds the current will increase to 13 Amps and continue increasing in 3 Amp increments until 180 Amps or greater if the increment does not equal the OHMIC END CURRENT is reached After the end current is reached the IV Curve will stop the IV curve data file will close and standard testing will resume 33 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation File Settings There are two interfaces for manipulating data files the FILE SETTINGS tab control and a DATA FILE dialog box included during startup The FILE SETTINGS are used to control how the data files are written whereas the DATA FILE dialog is used to control the contents of the data files For a detailed description of the DATA FILE dialog refer to the Software Startup and Shutdown section of this chapter Table IV 7 lists the settings for the all data files Table IV 7 File Settings Close Data File Data File Prefix New File at Midnight Take Data for _ minutes after fault Max Time between file writes Figure IV 10 shows the FILE settings tab control The CLOSE DATA FILE control is used to manually open and close a data file usually between tests The DATA FILE PREFIX control is used to set the file name prefix After the prefix the date and time the file was opened is appended to the file name If the operator wishes to start a new data file at midnight each night to prevent the creation of very large
42. cations for the test station and schematic drawings of the individual systems are included in Appendix A Specification sheets and user manuals for individual test station components are provided in Appendix B included as a separate binder A Air System The air system plumbing is located just above the hydrogen system plumbing on the Superstrut frame above the right hand end of the bench see Figure I 1 Dry oil free compressed air is supplied to the inlet isolation valve of the air system located at the top right corner of the bench Air system plumbing is 3 8 stainless steel tubing and rated to 3300 psig A pressure regulator with a pressure gauge and coalescer reduces the pressure to approximately 30 psig provides pressure indication and removes water from the air stream A supply solenoid valve allows automatic shutoff of airflow through the system and a medium pressure relief valve set at 55 psig protects downstream components from overpressure The air system is equipped with both low range 0 20 slm and high range 0 200 slm mass flow controllers The procedure to switch controllers is simple and is provided in Chapter III Other components include a pressure gauge a pressure transducer and a low pressure relief valve set at 150 in WC See Figure I 2 for a photo of the air delivery plumbing Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description Figure I 2 Air System B Hydro
43. chdog at least every 2 seconds using a digital output signal in order to keep the watchdog relay closed A BACKPLANE START button is used to temporarily bypass the watchdog timer and supply power to the backplanes at startup Once the BACKPLANE START button is released the LabVIEW program continues to toggle the watchdog Should the computer freeze the watchdog will no longer be toggled and both the 24VDC and 5 VDC power will be lost The SAFETY ENABLE allows the high level faults to be latched Should a high level fault occur power to all of the power supplies will not be supplied again until someone manually resets the fault To reset the fault the SAFETY ENABLE button must be pressed and the fault condition must no longer be present 2 Low Level Software Initiated Faults The software handles all low level faults The test station operator can select whether a low level fault is enabled and the threshold for triggering the fault in the SAFETY SETTINGS see section IV A 1 If a low level fault occurs the control system opens individual solid state relays on the digital backplane thereby placing all hardware in a safe state solenoid valves closed contactors opened etc The LabVIEW program continues to iterate and toggle the watchdog timer 3 Normal Shutdown During a normal shutdown due to either a high level fault low level fault or deliberate stopping of the LabVIEW program program shutdown button on the front panel
44. cted If the pressure falls outside of the range a fault will be triggered The water reservoir will be automatically filled if the AUTOFILL button is selected If the reservoir fills for too long or too often a RESERVOIR FILL fault will occur Table V 1 describes some of the possible reasons that a low level fault might occur and what corrective action s should be taken If a fault shutdown does not occur when a known fault condition exists ensure the fault is selected in the SAFETY SETTINGS and the SAFETY ENABLED button is selected If both are selected use the SOFTWARE DEBUGGING procedures to verify the analog and digital data are being processed properly 55 Operations and Maintenance Manual Chapter V PEM Fuel Cell Test Station Troubleshooting Table V 1 Troubleshooting a Low Level Fault Fault Possible Reasons Corrective Action Low Cell e Refer to the Fuel Cell Faults Voltage section of this chapter High Fuel Cell Stack is producing more heat Check that the fault setpoint Temperature than can be removed by the temperature is not set too low cooling system Usually the stack should run near 60 C and shut down near 65 C Make sure the heat exchanger fans are on and heaters are off Thermocouple reading Make sure operating incorrect temperature thermocouple is plugged into the Electrical Panel Make sure the analog input signal is being read in and scaled properly High Hydrogen Pressure
45. d the relief valve setpoint 150 in WC The air temperature upstream of the fuel cell should be kept above 0 C at all times During continuous operation the airflow should be maintained at 200 to 300 stoichiometry 2 to 3 0 01659 sIm Amp cell The airflow rate must always exceed 0 5 slm cell when fuel cell current exceeds 0 Amps 2 Hydrogen Supply Hydrogen supplied to the test station must be industrial grade min 99 95 pure Hydrogen must be free of carbon monoxide hydrogen sulfide and other catalyst poisons The hydrogen delivery pressure must not exceed 6 psig Hydrogen purges of approximately 1 second duration must be provided at 1 to 20 minute intervals depending on current density 3 Water Circulation Temperature Control The water flow rate must be between 0 2 and 5 0 lpm depending on current density and water pressure Water temperature should be controlled to 50 to 65 C e The water temperature at the fuel cell inlet must be higher than 5 C e Fuel cell stack temperature must not exceed 70 C 12 Operations and Maintenance Manual Chapter II PEM Fuel Cell Test Station System Requirements e Water pressure at fuel cell inlet must not exceed 100 in WC The pressure relief valve located near the fuel cell inlet is set to relieve pressure at 120 in WC 13 Operations and Maintenance Manual Chapter III PEM Fuel Cell Test Station Test Station Hardware Operation Chapter Ill Test S
46. data files during long term operation the NEW FILE AT MIDNIGHT checkbox should be selected After a low level fault is detected data will be written to the data file for the length of time entered in the TAKE DATA FOR _ MINUTES AFTER FAULT control Data are written to the data file every time one of the variables written to the file has changed by more than the selectable threshold specified in the DATA FILE dialog since the last time data were written to the file If the variables are not changing by more than the threshold data are written to the file every MAX TIME BETWEEN FILE WRITES Safety Test Close Data File Data File Pref FCTS Mew File at Midnight ke Take Data for ST minutes after fault Max Time between file writes 86 sec Figure IV 10 Front Panel File Settings 34 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Test Settings Table IV 8 and Figure IV 11 display the TEST settings Table IV 8 Test Settings Settings e Stop Program at FC Hours DAQ Scan Rate Hz The TEST settings tab control is used to control the parameters associated with individual tests A test can be terminated when the fuel cell has accumulated a certain number of hours under load by using the STOP PROGRAM AT _ FC HOURS control The DAQ SCAN RATE control can be used to specify the amount of time that elapses between consecutive scans of the backplanes Scanning of th
47. de To tighten the fitting apply the appropriate size wrench to the Swagelok nut and the fitting it screws on to While holding the fitting stationary turn the Swagelok nut clockwise until tight Pressurize the system and recheck for a leak 4 Valve and Regulator Cross Leak Checks A valve or regulator cross leak can cause improper system operation While performing routine operation and maintenance procedures the operator should closely monitor system response to valve manipulations and watch for symptoms that may indicate a cross leak problem Early detection of a cross leak will allow repair and or replacement of the defective part before further damage occurs 5 Deionization Cartridge Changeout In order to inspect and or replace the resin cartridge the test station must be shut down and the water circulation system isolated and depressurized Prior to changing out the cartridge perform all the corrective actions presented in the troubleshooting section The procedure is as follows 1 Ensure the test station is shut down 2 Close the blue handled water supply valve located at the back top center of the test station 3 Open the water systems drain valve located under the water reservoir and connect the cooling water inlet hose to the quick connect under the reservoir 4 Once the system is drained place a bucket under the blue cartridge housing While supporting the weight of water filled sump loosen the sump by turning coun
48. ded ensuring that there is no stress on the flex hose Reinstall the safety cap on the cylinder Unfasten the cylinder safety chains and move the spent cylinder from the bracket and secure to the off service position or remove from the area using a cylinder dolly Secure the full replacement cylinder in place Remove the full cylinder s safety cap and inspect and clean the threads on the cylinder s outlet fitting Install the regulator by securely tightening the CGA nut onto the cylinder counter clockwise If necessary tighten the flex hose from the regulator to the hydrogen plumbing inlet tee Close the hydrogen vent valve and make sure the hydrogen supply manual valve located upstream of the filter and the low pressure regulator is closed 17 Operations and Maintenance Manual Chapter III PEM Fuel Cell Test Station Test Station Hardware Operation 13 Crack open then immediately close the cylinder valve Perform a leak check of the cylinder CGA fitting by monitoring gauge pressure or using a soap solution If a leak is found tighten the fitting and recheck until a leak no longer exists 14 Open the cylinder valve 2 turns 15 Turn the adjustment knob clockwise until 80 psig is indicated on the delivery gauge 16 Open the regulator outlet valve Perform a leak check of the flex hose fittings using a soap solution If a leak is found tighten the fitting and recheck until a leak no longer exists 17 Crack open then close t
49. density of the hydrogen air mixture is similar to that of air As a consequence of these dispersion properties hydrogen gas tends to disperse readily and form an ignitable mixture with air However in an unconfined atmosphere this gt Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety mixture will quickly dilute to levels below the lower flammability limit So although the rapid mixing properties of hydrogen lead to a more rapid formation of a combustible mixture they also lead to a faster dispersal and generally shorter duration of a flammable hazard than for other fuels on an equal volume basis Hydrogen Gas and Flame Detection Hydrogen is a colorless odorless and tasteless gas Its presence cannot be detected by human senses In addition the unique characteristics of a hydrogen fire make it difficult to perceive with the human senses In contrast to other hydrocarbon fuels which radiate most of their energy as visible light and heat a hydrogen flame radiates significantly less heat and virtually no visible light Instead significant energy from a hydrogen flame is radiated in the ultraviolet region As a result hydrogen burns with a pale blue almost invisible flame that is almost visually imperceptible in artificial light or daylight Equally important human physical perception of the heat from a hydrogen fire doesn t occur until direct contact with the combustion gases A broom has been used
50. digital output should be used to switch the blower on and off in software A 120 VAC switched outlet is also provided on the electrical panel for controlling such devices Regardless of the blower power supply voltage signal voltages can be provided to the blower controller using one of the analog output channels Use the following procedure to switch to air blower operation 1 Shut down the test station 18 Operations and Maintenance Manual Chapter III PEM Fuel Cell Test Station Test Station Hardware Operation 2 Replumb the air delivery system to accommodate the blower Do not attempt to use the air delivery hardware that is connected to the MFCs For the current blower control algorithm to work an airflow transducer must be installed 3 Power the blower If using AC plug the blower into one of the switched outlets and note which outlet you used If using DC plug the DC power supply into an AC switched outlet 4 Connect the analog input wires from the airflow meter to the BLOWER AIRFLOW channel on the analog input backplane 5 Connect the analog input wires for the pressure transducer into the BLOWER PRESSURE channel 6 Connect the power lines for the transducers Connect the analog output wires to the blower motor controller the analog output signals can not be used to source more than 20mA See section IV C 1 for the software modifications necessary to operate a blower F Test Station Power The Safety Tray c
51. dplate Hydrogen enters the top left corner of the left endplate through a 3 8 fitting and leaves when purged out of a 1 2 fitting on the bottom right corner of the left endplate WARNING The Swagelok fittings connected to the stack should be securely tightened with a wrench Use the minimal amount of force necessary to prevent leaks Keep in mind that all connections are for low pressure systems DI water enters the stack in the bottom right corner above the purge fitting of the left endplate removes or supplies heat in the power section flows through the humidification section and leaves the stack in the bottom left corner of the right endplate The water lines are connected to the fuel cell using plastic quick connect fittings A small air vent hose is connected from the bleed valve on the right end plate to the tee located on the top of the water reservoir Electrical connections are made to the front of the stack the side without the VTaps The positive red cable is connected tightly to the right bus plate and the negative black cable is tightly connected to the left bus plate Two cables with individually numbered alligator clips are used to monitor cell voltages The VTaps are connected along the back of the fuel cell starting with tap 0 placed on the leftmost graphite tab when facing the front of the stack The cell numbers increase from the left to the right with cell 1 being the first cell on the left The VTaps are progr
52. dware problems where the software is functioning but may not be executing as intended you need to differentiate between software and hardware faults In the block diagram place a probe upstream of the Data IO subroutine on the array that contains the data you are investigating For example if the hydrogen supply solenoid is not opening when you press the H2 SUPPLY button on the front panel 1 Place a probe on the DIGITAL IO array 2 On the probe select the channel that contains the H2 SUPPLY data Change the state of the solenoid and check to see that the digital output from the software changes 4 Ifthe probe shows a change in state of the supply solenoid you now know that the software is not the root of the problem 5 Look at the digital backplane and make sure the light next to the module that controls the supply solenoid is changing state when the H2 SUPPLY button is pressed on the front panel 6 Ifthe light on the backplane is changing states you are now dealing with a problem in the connection between the backplane and the solenoid valve or the solenoid valve itself If the light is not responding the problem lies somewhere in the DAQ hardware These general procedures can be used regardless of the type of signal being tested For analog input data probe the value coming into the program and compare it to the value at the backplane For analog output data probe the value being sent from the software and 54 e
53. e backplanes consists of acquiring the analog input data from all four analog input backplanes sending the analog output data from both analog output backplanes and sending and receiving data on the digital lines Data acquired from the backplanes are not buffered If the DAQ SCAN RATE is increased beyond the speed at which the program is capable of iterating the program will iterate as fast as possible If faster scan rates are desired the SCAN RATE MODE control should be placed in the FAST position This mode of operation avoids updating processor intensive displays and results in faster program iterations Cooling Safety Test Stop Program at 2100000 FC Hours DAD Scan Rate 000 Hz Figure IV 11 Front Panel Test Settings Dynamic Graphing and Spare Indicators The dynamic graphing area is used to display data Figure IV 12 displays the dynamic graphing tab frames and the cell voltage plots 35 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation V vs Time IV Curve BP vs Flow Additional Channels 980 300 800 700 600 500 400 300 200 100 15 50 30 16 20 00 Select YT aps Figure IV 12 Front Panel Cell Voltage Plots The V vs TIME IV CURVE and BP vs FLOW tabs display plots of cell voltages over time average cell voltage versus current density and air inlet pressure versus airflow respectively Each plot displays data even i
54. e of the tee 4 Set up a compressed nitrogen test rig which includes a high pressure nitrogen cylinder regulator and hose a pressure gauge with the appropriate pressure range and a vent valve 5 Connect one open end of the tee to the test hose cap the other open end and secure the hose or relief valve to a stationary object with straps 6 Slowly raise pressure by adjusting the regulator until gas relieves from the valve and note the lifting pressure Lower the regulator delivery pressure to stop the valve from relieving 7 Ifthe lifting pressure is at the desired setpoint go to next step If the lifting pressure is not within the setpoint range 1 psig or 10 in WC as appropriate the valve requires adjustment Depressurize the test hose prior to making an adjustment Refer to the appropriate component specification sheet for a diagram of the PRD and adjust the setpoint as follows e Loosen the locking screw with hex head wrench Turn the adjusting screw clockwise to increase the setpoint or counter clockwise to decrease the setpoint Tighten the locking screw and go to step 6 above and retest Continue to make adjustments until the setpoint is reached Remove the PRD tee from the test hose and reinstall into system 9 Tighten the Swagelok nuts on each side of the tee 10 Restore the system to normal and leak check all fittings that were loosened 3 Leak Checks The most important maintenance task to be perform
55. e test station operator are CPU intensive and decrease the rate at which data can be collected Consequently when high speed acquisition is necessary the SCAN RATE MODE control can be set to the FAST position and the dynamic graphing and settings tab controls will not be displayed Safety Controls and Settings Table IV 5 lists the controls and settings for the test station safeties Table IV 5 Safety Controls and Settings Controls Settings e Program Shutdown Cell Voltage Enable Safety Shutdown Minimum Cell Voltage mV cell Safeties Enable Temperature Enable Maximum Temperature deg C H2 Pressure Enable Minimum H2 Pressure psig Maximum H2 Pressure psig Water Fill Enable Fill nolessthan min apart Fill no longer than min Figure IV 6 contains a diagram of the safety controls and settings H2 Air Cooling Load File Safety KE CellVoltage Min SEI mV cell v Temperature Max FN deg C v H2 Pressure From Sin to FN psi v Water Fill Fills no less than EE min apart Fill no longer than 802 min SAFETIES Safety Shutdown e Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Figure IV 6 Front Panel Safety Controls and Settings The SAFETY settings which are accessible in the SAFETY settings tab control on the front panel are for low level software faults In the SAFETY settings both checkboxes and thresholds ar
56. e used to set fault parameters If a check box is enabled checked then the variable of interest will be compared to the threshold setpoint If the variable falls outside of the threshold range a low level software shutdown will occur When a low level fault occurs the test station is placed in a safe state solenoid valves closed contactors opened signal outputs set to OV etc The CELL VOLTAGE enable prevents the fuel cell from running under load if a cell voltage is less than the minimum CELL VOLTAGE The TEMPERATURE enable ensures that the fuel cell operating temperature remains below the maximum TEMPERATURE The H2 PRESSURE enable ensures a hydrogen pressure between the minimum and maximum specified values The WATER FILL enable is used to ensure that the reservoir is not filled for too long or too often In addition to enable any of the low level safeties the SAFETY ENABLE control located in the SAFETIES control box must be enabled In summary to generate a low level fault the safeties must be enabled the appropriate safety setting enable checkbox must be checked and one of the conditions monitored must fall outside of the specified range For example assume the minimum cell voltage is set at 500 mV If VTap 4 falls to 480 mV a low level fault will be triggered if the CELL VOLTAGE enable box in the SAFETY settings is checked and the SAFETIES are enabled WARNING During normal operation all of the low level faults should be enabl
57. ed Following system startup the test station should be operated with the safeties enabled as soon as the cell voltages are above the minimum threshold The SAFETY SHUTDOWN control when depressed simulates a low level fault condition During a low level safety shutdown the hardware is placed in a safe state the data file remains open for the time period set in the FILE settings tab control and the test station program continues to run In contrast when the PROGRAM SHUTDOWN control is pressed all hardware is placed in a safe state the current data file is closed and the test station program is stopped Load Settings Table IV 6 lists the settings for the electronic load Table IV 6 Load Settings Settings e Enable Load e Range Mode e Constant Current Controls e Pulsing Controls e V Curve Controls 30 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Driving Cycle Controls Figure IV 7 contains a diagram of the LOAD SETTINGS tab control when running in constant current mode Whenever changes are made to the load settings the DynaLoad driver updates the electronic load using GPIB communication The load is updated only after a change to the settings has been made Cooling Load File Safety Test Enable Load Range EETATISITEIUENTUTEESw Mode KINENA EE EE Constant Pulsing IV Curve Driving Cycle Setpoint Eoo NA Wy Limit
58. ed especially on the hydrogen plumbing is periodic leak checking Leak checks should be performed every 3 months and after any system maintenance whether corrective or preventive System operators can perform leak tests with a portable gas detector or Snoop type leak checking fluid Leak checks using these methods can be performed with the system running and fully pressurized Another method for leak checking is the pressure drop test With the system shut down and pressurized record all pressure gauge and pressure transducer values After 1 hour or longer if feasible record the pressures again and compare them to the previous values A decrease in pressure will indicate a leak and its approximate location in the system Snoop or a portable gas detector can then be used to locate the leak precisely If the leak is from a component or section of the system that cannot be fixed or 62 e e e Operations and Maintenance Manual Chapter VI PEM Fuel Cell Test Station System Maintenance retightened that section or component must be replaced The system must be depressurized before the leak can be fixed Note Never attempt to tighten a leaky fitting while under pressure Most likely the leak is from a loose Swagelok fitting As stated in the Swagelok Tube Fitter s Manual these connections can be disconnected and re tightened many times The same reliable leak proof seal can be obtained every time the connection is rema
59. en the hydrogen vent valve and ensure pressure on the regulator delivery pressure gauge decreases to 0 psig 4 Follow the MAINTENANCE procedure on the filter specification sheet provided in the Component Spec Sheets binder in Appendix B 5 Close the delivery supply manual and hydrogen vent valves when maintenance is completed 7 Hydrogen Vent Line Purging The high pressure vent line exits the lab and vents gas outside the building During the winter months it is possible for ice to form and plug the vent line outlet fitting In order to identify a blocked vent line it is recommended that the vent valve be periodically opened and closed to purge hydrogen through the vent line and remove any ice When purging ensure that gas flow is heard exiting the vent line At a minimum the vent line should be purged before every test station start up during the winter months B Safety System The test station safety system includes several components that require periodic maintenance Procedures are as follows 1 Smoke Alarms The smoke alarms have procedures detailed on pages 5 and 6 of the specification sheets for cleaning and maintaining the alarms It is recommended that the alarms be tested annually with the test bench running To test the alarm 1 Use the appropriate Startup Procedures outlined in Chapter IV to get the test station online 64 Operations and Maintenance Manual Chapter VI PEM Fuel Cell Test Station System Maintena
60. ent being serviced and knows how to tagout or lockout the equipment properly and safely e Ifthe equipment to be serviced is in use shut down the fuel cell test station Isolate any electrical equipment to be serviced from the electrical system by disconnecting its source of power Make sure that no residual energy e g capacitors presents a safety threat e Depressurize the hydrogen gas system if any gas system equipment is to be serviced e Tagout or lockout the opened electrical disconnects electrical power plugs or closed gas system valves that have been used to isolate the equipment being serviced e Check that no personnel are working on or near the equipment to be serviced then test that the electrical disconnect tagout lockout is in effect by trying to start the equipment If the equipment starts it has not been isolated correctly If the equipment does not start proceed with servicing e When servicing is completed make sure all personnel are clear of the equipment remove tagout lockout devices close the electrical disconnect s and re start equipment as appropriate F Material Safety Data Sheets MSDS A Material Safety Data Sheet MSDS for hydrogen is included in Appendix D of this manual MSDSs provide safety information on any potentially hazardous or toxic substances An MSDS is required to provide the following information e Product and company information e Composition ingredient information 81 Opera
61. er the cylinder is FULL IN SERVICE or EMPTY or has RESIDUE e Store empty cylinders separately from full cylinders e Call appropriate personnel to pick up cylinders that are no longer needed C Safety Equipment and Guidelines The following instructions and guidelines will help system operators to use the facility s safety equipment effectively 1 Fire extinguishers Fire extinguishers are located in the fuel cell test station area See Section C 2 in this chapter for guidelines on controlling hydrogen fires and other types of fires Fire extinguishers need to be clearly labeled according to the class of fire they are suitable for These codes as given in NFPA 10 are Class A Fires in ordinary combustible materials such as wood cloth paper rubber and many plastics Class B Fires in flammable liquids oils greases tars oil base paints lacquers and flammable gases Class C Fires that involve energized electrical equipment where the electrical conductivity of the extinguishing medium is of importance when electrical equipment is de energized extinguishers for class A or B fires may be safely used 75 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety Class D Fires of combustible metals such as magnesium titanium zirconium sodium lithium and potassium Fire extinguishers must be kept in their designated locations and in plain sight Operators should n
62. erruptible power supply for entire station Station area H Sensor Station area smoke detector Computer watchdog timer hardware shutdown if computer freezes Automatic emergency shutdown Manual emergency shutdown Hydrogen pressure relief device 210 psig Water reservoir overfill drain Station area vent fan Station Requirements Voltage 120 VAC Frequency 60 Hz Current 30 amps DI water 5 uS Pressurized H 5 3000 psig Compressed oilless Air 20 100 psig Water lines for exhaust H and Air H Vent fan The software will produce a data file recording system data The maximum time interval between successive records will be user selectable In addition the system will record data whenever selected channels change by more than a selectable amount The system will automatically open new data files at midnight or other selected times The user may include header lines in the file to record characteristics of the fuel cell being tested The software will automatically shut down the system whenever specific analog or digital inputs exceed user selectable limits The reason for the shutdown will be displayed on the monitor The state of the hardware safety circuit is one of the digital inputs to the software The hardware safety circuit is a software independent unit that will automatically disconnect the electronic load close the hydrogen and air supply valves and sound an alarm Operations and Maintenance Manual l Appendix A PEM Fuel
63. ers with the protective caps in place Posting and Hazard Identification The hazard classification and or the name of the gases being stored should be prominently marked in container storage areas and NO SMOKING signs should be posted where appropriate Material safety data sheets MSDSs for the product s should be readily available and should be consulted for information on the specific hazards safety precautions and related emergency response procedures Gas storage cylinders should be marked to identify the gas contents and fill pressure Properly label cylinders with stencils DOT shoulder labels cautionary side wall labels 173 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety or tags to identify the contents Do not remove these labels without specific authorization from your appropriate safety officer Color codes are not used to identify contents Adequately Secured All compressed gas cylinders in service or storage should be secured to prevent them from falling Cylinder and manifold racks should be equipped with two chains whenever possible If available both chains should be used to secure the cylinders Compatibility Cylinders should be separated by compatibility of contents For example oxidizers should be kept separate from combustibles or flammables by a minimum distance of 20 ft or by a non combustible barrier that is at least 5 ft high with a fire resistance rating of at least one h
64. escription of the problem to 707 826 4347 or emailing a description of the problem to serc humboldt edu ii Operations and Maintenance Manual PEM Fuel Cell Test Station Table of Contents E EE vi Eist Of JCPODVIBNS a oii ope rude dos EE vil EES n viii Kee EE viii Chapter I Test Station Description a oa esca odas deitate quta dente ensis 1 AC Air System 5 35 alo dean raro tiii der Gods ver dent I I Ehe ve adel Or epo es aah e eap ver aa 2 Be Hydrogen artgerecht sit 3 G Water Circulation System EES 4 D Electrical System Electronic Load and UPS eese 5 E Monitoring and Control Hardware isc sese testa eset pe edo tesa ARR t IRR Deae disk dua 6 B Test Station SOfLWate isses ere EENS EEN 7 G Safety Control S ystems ce o b dede Ee 8 High Level Software Independent Faults 5 een rt een nennees 9 2 Low Level Software Initiated Faults o er e taa das 9 3 erte Shutdown erer geed eebe Are H 4 Emergency e EE 10 Chapter I System Requirements eee ege ed 11 A TestStation E E EE 11 l Oil Free Compressed Air usce ca eo x va e ea bi adve 11 2 Hydrogen Supply and VelttnB EE 11 Oe EE EE 11 4 Water Drainage a sees ic tarta dis veia tort s aea Arcus reae avin 12 5 Power Supply EE 12 B uelGelb Requirements aedes oe On o eb v ee bea ro toute 12 NEP CIO UOTIS PME 12 2 EE 12 3 Water Circulation Tem
65. esting 3 Hydrogen Detector The manufacturers of the hydrogen detector recommend weekly tests of the hydrogen sensor To test the sensor on a weekly basis refer to page 33 of the sensor manual It is also recommended that the sensor be tested with the Safety System every year To test the sensor with the Safety System 1 Use the appropriate Startup Procedures outlined in Chapter IV to get the test station online 2 Remove the hydrogen inlet line from the fuel cell stack 3 Place the hydrogen inlet line next to the sensor 65 Operations and Maintenance Manual Chapter VI PEM Fuel Cell Test Station System Maintenance 4 Close the supply manual valve upstream of the supply solenoid Open the supply solenoid 6 Slightly crack the manual valve until gas flows and the sensor responds to the increased hydrogen concentration 7 After the transmitter triggers a hardware shutdown should occur and the Safety Tray siren should alarm Close the manual valve 9 Silence the alarm by pressing the SIREN BYPASS button on the Safety Tray front panel 10 Close the solenoid valve and open the manual valve 11 Reconnect the hydrogen inlet line to the stack 12 When the transmitter stops triggering press the SAFETY ENABLE button on the front panel of the Safety Tray 13 Press the BACKPLANE START button on the front panel of the Safety Tray 14 You are now ready to resume normal fuel cell testing C Transducer Calibrations
66. f its tab is not selected Consequently at any time a different plot is selected historical data can be viewed Each plot has a limit to the number of points that can be plotted and the period over which data are displayed depends upon the HISTORY SIZE number of points plotted and the display rate to the screen controlled in the DISPLAY TASK subroutine The ADDITIONAL CHANNELS tab is included for displaying data from instruments that are added to the test station Refer to the Modifying Software section of this chapter for a detailed description of adding instruments While observing individual cell block voltages over time the user can select which blocks to monitor Pressing the SELECT VTAPS button will display a dialogue box that will prompt the user to choose which cells to monitor Once the appropriate cells have been selected the plot will be erased and new data will be displayed The X RANGE control is used to manipulate the length of time that data will be displayed for After changing the X RANGE and waiting for the selectable amount of time to elapse if the data does not span the entire width of the graph then the HISTORY SIZE is too small and must be increased Refer to the Modifying Software section of this chapter for a detailed description of modifying the graphs 36 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation The ADDITIONAL CHANNELS frame shown in Figure IV 13 di
67. f the water reservoir and maintain an adequate water level in the reservoir When the AUTO FILL control is enabled and the water level drops the float to its lowest setting the float switch closes and the water fill solenoid valve opens The water fill solenoid valve will remain open until the float switch opens and then remain open for a preset period of time as specified by the reservoir FILL TIME in the COOLING SETTINGS tab control Pressing the MANUAL FILL button will directly open the water fill solenoid valve and fill the reservoir for as long as the button is depressed The indicators displayed below the cooling controls in the COOLING system control box include the fuel cell operating temperature TFC located on THERM 1 AMBIENT TEMP additional thermocouples THERM 2 through THERM 5 water FLOWRATE and water CONDUCTIVITY Temperature probe locations and labels can be easily changed as described in the Modifying Software section of this chapter Fuel Cell Subsystem Table IV 4 lists the indicators used to monitor the fuel cell 21 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Table IV 4 Fuel Cell Indicators Vtaps 1 32 mV Stack Voltage V Stack Current A Stack Power W Current Density mA cm Power Density mW cell cm Total hours of operation Total amp hours produced FUEL CELL Current Density Power Density 500 250 450 225 400 200 350
68. for locating small hydrogen fires The idea is to hold the broom out in front of you while approaching the area where the hydrogen fire is suspected A dry corn straw or sage grass broom will easily ignite when it comes in contact with the flame A dry fire extinguisher or throwing dust into the air will also cause the flame to emit visible radiation Flammability and Ignition Hydrogen has a much wider range of flammability in air 496 to 7596 by volume than methane 5 to 17 by volume propane or gasoline and the minimum ignition energy for a stoichiometric mixture is about an order of magnitude lower 1 16 that of methane These characteristics would tend to indicate that flammability is a greater risk for hydrogen than for other fuels However these comparisons may not be as significant as they appear In many accidental situations the lower flammable limit LFL is more important The LFL for hydrogen is similar to that of methane about twice that of propane and four times that of gasoline In addition the minimum ignition energy for hydrogen at the LFL is also similar to that of methane Weak ignition sources such as an electrostatic spark are often noted as being sufficient to ignite a combustible hydrogen air mixture However a weak electrostatic spark from the human body releases about 10 mJ which is enough energy to ignite methane propane gasoline and other fuels as well Combustion Characteristics Hydrogen oxidizer m
69. form Operating System Computer Specs as Desired Data logging Automated Electronic Load 4 kW DynaLoad with GPIB interface software or manual control Voltage limited 0 10 V 0 50 V 0 100 V 0 5 Current limited 0 20 A 0 200 A 0 600 A 0 5 Power limited 0 4 kW x 396 Software based IV curve testing Data Monitoring Automatic longterm data logging programmable time interval Individual cell voltages 30 channels 0 1200 mV cell 1 mV cell Fuel cell current with alternate ranges 0 1000 A 0 03 A 0 500 A 0 015 A H inlet pressure 0 30 psia 0 4 96 H inlet flow 0 100 slm x 1 0 slm Air inlet pressure 0 5 psig 0 25 Air inlet flow 0 100 slm 1 0 slm 0 500 slm 5 0 slm Water temperature in out heat exchanger 0 100 C Water temperature in out fuel cell 0 100 C Water flow meter 1 10 L min 396 DI water conductivity 0 10 uS 296 Fuel cell operating temperature 0 100 C Operations and Maintenance Manual Appendix A PEM Fuel Cell Test Station System Specifications and Drawings Specifications continued Software Safety Triggers with alarms Low cell voltage programmable limit Low high Hz inlet pressure programmable limit Low high air inlet pressure programmable limit High stack temperature programmable limit High cooling water conductivity programmable limit H system leak programmable limit Emergency shutdown Hardware Safety Triggers with alarms Unint
70. gen System The hydrogen system supplies hydrogen gas from high pressure cylinders to the fuel cell stack reducing the gas pressure to an appropriate level along the way Hydrogen system plumbing is located just above the right hand end of the bench A hydrogen cylinder rack adjacent to the test station bench top is designed to hold Compressed Gas Association approved Size 44 cylinders Only one cylinder of hydrogen will be in service at a time The high pressure gas from the in service cylinder enters a two stage regulator set to deliver gas at 40 100 psig The hydrogen gas then passes via a flex hose to the hydrogen delivery plumbing mounted to the Superstrut The hydrogen plumbing is also 3 8 stainless steel tubing rated to 3300 psig A vent valve and a supply valve provide depressurization and isolation capability when performing system maintenance or exchanging hydrogen cylinders Hydrogen gas pressure is next reduced to 0 5 to 5 0 psig by a single stage low pressure regulator A pressure relief valve set at 150 psig is located upstream of the low pressure regulator and protects the regulator from overpressure Another pressure relief valve set at 9 psig is built into the regulator and provides downstream overpressure protection for the fuel cell An in line 7 micron filter removes debris from the gas stream to protect downstream components and the fuel cell Other components include a mass flow transducer to monitor gas flow and a suppl
71. gic places all hardware in a safe state before shutting down the test station In addition the shutdown section includes the logic that initializes the front panel controls in preparation for the next test station startup B Startup and Shutdown The following procedures should be used when running the test station A complete test station power up or shutdown is used when the system has been shutdown and all AC power is disconnected from the bench Normal startups and shutdowns occur in between tests Refer also to the Quick Startup and Shutdown Procedures outlined in Appendix C 42 e Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Test Station Power Up 1 Turn the UPS on 2 While pressing the SIREN BYPASS button on the Safety Tray Panel turn the POWER switch also on the Safety Tray Panel to the ON position Release the SIREN BYPASS button 3 Press the SAFETY ENABLE button on the tray If one of the hardware safeties has triggered the siren will sound and the LEDs will indicate which hardware fault has occurred Pressing the SIREN BYPASS button will silence the siren until the SAFETY ENABLE button is pressed Continue to troubleshoot any hardware safeties until the Safety Status LED is green 4 Turn on the Computer and launch the LabVIEW test station program 5 Connect all subsystem lines electrical cables VTaps and thermocouples as described in Section A
72. he humidification section of the stack Refer to the Fuel Cell Faults section of this chapter for further details Reservoir fills for too long Make sure the RESERVOIR FILL TIME COOLING SETTINGS is not greater than the FILLS NO LONGER THAN _ MINUTES SAFETY SETTINGS setpoint Drain the reservoir Compare the digital output value to the FILL SOLENOID with the software output and make sure the FILL SOLENOID is open for time intended by software Float Switch not working Use the Software Debugging procedures in this chapter to determine if the float switch is working properly 57 Operations and Maintenance Manual PEM Fuel Cell Test Station E Fuel Cell Faults Fuel cell faults can present themselves in numerous ways From anode flooding to cross leaks there are a number of reasons a stack may perform poorly either temporarily or permanently 1 Troubleshooting The operator should continuously monitor fuel cell stack performance during experimental testing Poor performance is typically defined by relatively low cell voltage at a given current density The more the system parameters load air stoichiometry purge frequency and duration etc are changed the more likely an operational problem will occur A summary of the symptoms that may be observed during stack operation is provided in Table V 2 The symptoms are used to identify fuel cell problems and thus help to determine the possible ro
73. he CLEAR SAFETY FAULT button appear The CLEAR SAFETY FAULT button must be pressed before the system can be run again Note this CLEAR SAFETY FAULT button is not related to the SAFETY ENABLE HARDWARE button on the front panel of the Safety Tray The hardware SAFETY ENABLE button is used only for high level hardware shutdowns For a detailed description of the procedures used during shutdowns refer to the Startup and Shutdown section of this chapter 37 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Warning Manual Shutdown Low Level Fault Figure IV 14 Error Status display 2 Block Diagram The block diagram contains a graphical depiction of the software logic that controls the test station The block diagram for the test station contains four main sections startup subtasks front panel display logic and shutdown Figures IV 15 and IV 16 display these sections of the block diagram 38 Chapter IV Test Station Software Operation Operations and Maintenance Manual PEM Fuel Cell Test Station EES pci Gsm m em AGES Di een el ee EE Be Heng e C44 EJ masm Eesen C es panos ml Subtask Section Figure IV 15 Startup and Subtask Section of the Block Diagram 39 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Shutdown Section Display L
74. he delivery valve Back out the regulator DynaLoad range chart is shown at right gt RBL 100 600 4000 P FULL PO Vor SO Vos T00 Volts Voltage Current 20 Amps 200 Amga 600 Amps OrrRATING Monks Constant Current Dro Sechs Full Seay Cure Prog Accuracy GG Ranges p 258 20A son ik Heguabon z0 15 of Ful Scale Constan Resistance Exporddad in Ampavolt Prog Accuracy OS of Full Soe Bosguiaton 27 of Full Scale High Ohm Mode Range 20A ZA GC TOV Us AN D 00 AM o 30 AM ay D FAM o 2AV a AN YEN 0 00 AN 0 5 AV T JAW Lyw Giaa Mode Range A TA BHA UV D D AIV D 100 GV D 30a ty BV D 2 AN D 20 AN 80 A v TN D And D 10 AN 0 30 AV Constant Volage D Selected Full Scale Prog Accuraey COVEY Kees 02495 DV Rang x 055 Reguisten 10 155 of Full Scale Consin Pure D ip 4000 Vives Prog Accuracy rio Ful Soe Aequaton SES Ful Some Shon Circuit 6 003 Gha Max METERS a 2A SO Ammeier AccUanAGOMET Dep S085 20 259 SR L na Ria iOmA d sch tA age BV Operations and Maintenance Manual Appendix D PEM Fuel Cell Test Station Material Safety Data Sheet Appendix D Material Safety Data Sheet
75. he vent valve to purge any entrained air from the system 18 Open the hydrogen supply manual valve The hydrogen system is ready for service D Switching Air Mass Flow Controllers The air system is equipped with both a low range 0 20 slm and a high range 0 200 slm mass flow controller To switch from one controller to the other the test station must be shut down 1 Close the AIR SUPPLY SOLENOID on the front panel 2 Switch the cable to the desired controller Loosen the two screws on the cable connector pull the connector off attach the connector to the other controller and tighten the screws 3 Point the 3 way inlet valve to the desired controller The valve handle points toward the in service controller 4 Disconnect the air inlet line from the stack 5 See Section IV C 2 for software procedures E Air Blower Operation An air blower can be used as an alternative source of air for the fuel cell stack Because of the pressure drop across system components and plumbing an air blower does not have the capability to supply the necessary amount of air through the system plumbing used for pressurized air The blower should instead be plumbed directly to the fuel cell using large diameter hose to minimize head loss The type of blower installed will dictate how the blower is integrated with the existing hardware A 24 VDC bus is available next to the digital backplane for powering the blower If the 24 VDC bus is used a
76. ic flow is delivered to the stack In the AIR system control box the AIR SUPPLY control operates the air supply solenoid valve or a digital control on the blower power supply It is used regardless of the AIR SOURCE selected When the MFC is selected as the AIR SOURCE and the AIR SUPPLY is closed the solenoid valve is de energized closed and a 0 volt control signal is sent to the air MFC via an analog output module When the AIR SUPPLY is open the air solenoid is energized open and airflow is dependent upon the airflow settings When the BLOWER is selected as the AIR SOURCE and the AIR SUPPLY is closed a digital signal is provided to a relay controlling the power supply to the blower When the relay is opened a 0 volt control signal is sent to the blower motor controller via an analog output module When the AIR SUPPLY is open the relay is closed and the desired airflow control signal is sent to the blower While the air SURGE button is depressed the desired airflow will be multiplied by the surge FACTOR specified in the bottom of the AIR settings tab control In the AIR system control box the indicators displayed below the air controls depend upon the air settings If the airflow mode is FIXED the stoichiometry SETPOINT is not displayed If the airflow mode is STOICHIOMETRIC the SETPOINT is displayed Regardless of the AIRFLOW MODE the ACTUAL stoichiometry AIRFLOW and inlet AIR PRESSURE are displayed Hydrogen Subsystem and Setting
77. igh pressure cylinders and reduces the pressure to a level appropriate for delivery to the fuel cell stack Water Circulation System Water is used as a heat transport medium in the test station to either heat or cool the stack using electric resistance heating and a heat Operations and Maintenance Manual Chapter I PEM Fuel Cell Test Station Test Station Description exchanger Water also circulates through the humidification section of the fuel cell stack to humidify the incoming air stream e Electrical System AC and DC electric power are used to operate the test station s instrumentation The electrical system also includes an electronic load used to absorb and control power produced by the fuel cell stack and an uninterruptible power supply UPS used to keep the test station running through utility brownouts or brief blackouts Monitoring and Control Hardware A standard computer combined with analog and digital data acquisition hardware is used to monitor and control the fuel cell subsystems Test Station Software Test station operation is controlled using LabVIEW software which also provides an interface between the operator and the test station s monitoring and control hardware Safety Control System A number of hardware and software controlled safety shutdowns ensure safe operation of the test station A detailed description of each system is given below along with labeled photos where appropriate Detailed specifi
78. il the percentage of hydrogen in air is consistently below 0 5 while the system is under pressure 2 Smoke Alarms The two smoke alarms connected in tandem will alarm until smoke is no longer detected If the smoke alarms are sounding leave the building and notify appropriate personnel of the potential hazard If the smoke alarms are not sounding investigate the possible sources of smoke 53 Operations and Maintenance Manual Chapter V PEM Fuel Cell Test Station Troubleshooting 3 Fan Alarm The FAN ALARM uses a differential pressure transducer referred to elsewhere in this manual as the ventilation flow transducer to detect the pressure differential between the hood and the exhaust trough in the floor If the pressure differential is not satisfactory the alarm will trigger Use the following procedures to troubleshoot a fan alarm 1 Check to ensure that the room ventilation system is running 2 Inspect the hood exhaust line for any obstructions B Clearing Safety Faults After a High Level fault has occurred the operator should follow the guidelines presented above to determine which fault occurred and why After the unsafe condition has passed follow the Startup After a High Level Fault procedures in Section IV B C Software Debugging There are two types of software debugging to consider code and hardware When debugging new or modified code follow the guidelines provided by National Instruments When debugging har
79. in the area has been disconnected spray flammable materials near the fire with a water mist or soak the materials in some other manner to prevent the fire from spreading e It is especially critical to spray the hydrogen cylinder with water if they are exposed to flame or extreme heat This will prevent the cylinders from rupturing If insufficient water is available to keep the cylinders cool evacuation of the area is recommended e Here is a chance that pure oxygen or compressed air is mixing with the burning hydrogen the flow of oxygen or compressed air should be shut off immediately Post warning signs and isolate the area until the fire and combustion hazard has been resolved 3 Electric Shock Hazards The fuel cell test station uses 120 VAC single phase power as well as 5 VDC 15 VDC and 24 VDC power for system operation and control In addition the test station is equipped to handle DC power output from a fuel cell ranging from 0 to 200 Amps DC and 0 to 30 VDC The 120 VAC power can produce a shock resulting in injury or death It is imperative that system operators follow standard electrical safety procedures when working with these components see the lockout tagout procedure below Remember that circuits on the test station may be energized even when the system is in standby mode In addition even when power to circuits has been disconnected stored electrical energy i e in capacitors or batteries may maintain high voltages
80. increments throughout the activation region The OHMIC END CURRENT is the current at which the IV curve stops The INCREMENT IN OHMIC REGION controls the current increment for the Ohmic resistance portion of the curve The TIME AT EACH STEP control is used to determine the amount of time that each increment in current will last For example if the end of the activation region occurs at approximately 6 Amps the ACTIVATION END CURRENT should be set to 10 Amps The INCREMENT IN ACTIVATION REGION should be set to a small value such as 1 Amp because small changes in current cause relatively large changes in the cell voltages in this region of the IV curve Based on stack performance and the testing objectives the OHMIC END CURRENT and the INCREMENT IN OHMIC REGION can be set Typically IV curves range from 0 600 mA cm 180 Amps for the stack provided and current increments of 3 Amps in the Ohmic region are satisfactory The TIME AT EACH STEP should take into consideration the response time of the instruments you are controlling Using mass flow controlled air and regulated hydrogen the time period should be at least 2 seconds to enable a quasi equilibrium in the fuel cell to be reached Using the IV Curve settings provided the IV curve will progress as follows When the START IV CURVE button is depressed a separate data file will be opened The current will increase from 0 to 10 Amps in 1 Amp increments After remaining at 10 Amps for the set num
81. input data are manipulated and stored in the CALCULATE DATA array in the CALCULATE DATA subroutine For example current and voltage analog inputs are multiplied to determine power Current and voltage are stored in the ANALOG INPUT array while power is stored in the CALCULATE DATA array The SAFETY TASK is used to handle the low level faults and warnings This subroutine checks all of the safeties selected on the front panel and controls the error dialog The hydrogen air cooling and load subsystems are controlled in the HYDROGEN AIR COOLING and LOAD subroutines The DATALOG subtask handles the writing of all data files Finally the DISPLAY TASK is used to determine whether data is written to the front panel The FRONT PANEL DISPLAY LOGIC section of the block diagram is separated into two areas the error handling and the indicator display The error handling logic is located in the bottom left portion of the case structure and is responsible for changing the state of the front panel controls which indirectly controls the hardware when these values are passed to the subtasks The indicator display area the rest of the logic is used to write data to the front panel Inputs from the user front panel controls are not handled in this section of the block diagram The shutdown section of the block diagram located to the right of the main while loop only executes after the front panel PROGRAM SHUTDOWN button has been pressed The shutdown lo
82. ire may be burning in a particular area it is best to stay away from that area If you must enter the area do so cautiously and slowly with an infrared detector to check your path in front of you Do not proceed if the infrared detector shows a significant heat source in your path If an infrared detector is not available hold a broom extended in front of you If the broom scorches or catches fire do not proceed Guidelines for Extinguishing Hydrogen Fires The only safe way to extinguish a flammable gas fire is to stop the flow of gas If the flow cannot be stopped allow the entire contents of the cylinder to burn Cool the cylinder and surroundings with water from a suitable distance Extinguishing the fire without stopping the flow of gas may permit the formation of ignitable or explosive mixtures with air These may propagate to a source of ignition Excessive pressure may develop in gas cylinders exposed to fire This can result in explosion regardless of cylinder contents initial pressure or gas type Cylinders with pressure relief devices PRDs may release their contents through such devices when exposed to fire Cylinders without PRDs have no provision for controlled release and are therefore more likely to explode if exposed to fire Small Fires Use one of the fire extinguishers located in the fuel cell test station area Large Fires Evacuate the premises and contact the fire department immediately dial 911 Stop the flow of
83. is pressed the watchdog timer will no longer be toggled and AC power to the 24 VDC and Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description 5 VDC power supplies will be disconnected AC power will still be supplied to the 15VDC power supply during and after normal shutdowns 4 Emergency Shutdown Should an emergency arise depressing the EMERGENCY STOP button on the front panel of the electronics cabinet beneath the bench will shut off all power supplied to the safety tray Alternatively if the area around the test station becomes hazardous personnel should leave the area and disconnect power to the test station by tripping the circuit breaker at the main electrical service panel In either case the electronic load and computer will continue to receive AC power via the UPS 10 a Operations and Maintenance Manual Chapter II PEM Fuel Cell Test Station System Requirements Chapter Il System Requirements The purpose of this chapter 1s to describe the support resources and infrastructure necessary to operate the test station and the fuel cell The test station requires A oil free compressed air B hydrogen supply and venting C deionized water D water drainage and E power Fuel cell requirements are given in terms of pressure flow temperature and hydrogen oxygen stoichiometry as discussed below Important If test station users make any changes to the configuration of the tes
84. is still present at the test station shut off electrical power to the test station by tripping the circuit breaker that provides test station power at the main electrical panel This will shut off power to all components on the test station except the control computer and the electronic load These components are supplied power via the UPS and this power cannot be easily disconnected 8 Post warning signs and isolate the area until the electrical hazard has been resolved E Safety Policies System operators must adhere to the following safety policies when operating the fuel cell test station Only trained authorized personnel should be allowed to operate and maintain the fuel cell test station e Personnel working with high pressure gases flammable gases and or electrical systems must have adequate training and experience e Use appropriate personal safety equipment on the job Wear safety glasses at all times when working in the fuel cell test station area or working with high pressure gases Wear hearing protection when working with high pressure gases Use the buddy system work with at least one other researcher present and ready to assist in case of an accident or emergency when performing any operation maintenance or troubleshooting tasks on the fuel cell test station Never perform system operation maintenance or repair tasks alone Be familiar with facility wide safety policies 80 Operations and Maintenance M
85. ixtures can combust either as a fire at a fixed point a deflagration or a detonation Depending on the rate of release of hydrogen from the source fires can produce outputs ranging from that of a small candle to a high pressure jet At a fixed point hydrogen gas can burn as a jet flame with combustion taking place along the edges of the jet where it mixes with sufficient air In a stationary mixture in the open with no confinement a flammable hydrogen mixture will undergo slow deflagration Deflagration refers to a flame that relies on heat and mass transfer mechanisms to combust and move into areas of unburnt fuel 71 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety If the flame speed is accelerated perhaps due to extreme initial turbulence or turbulence induced by obstacles or confinement the result is an explosion In the extreme case the flame speed becomes supersonic and results in detonation Once initiated detonation is self sustaining no further turbulence or confinement is required as long as the combusting mixture is within the detonatable range A detonation explosion is capable of causing much greater physical damage due to the significantly higher pressure that is generated as great as 20 times the initial stoichiometric pressure versus about 8 times the initial pressure for a deflagration The lower radiation from a hydrogen flame makes the flame itself hotter than a hydrocarbon flame and ob
86. ized by subsystem and arranged by color Figure I 7 includes a screen Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description Hydrogen System Stack Monitoring Dynamic Graphing i COOLING Winter enbar Vonast Deag tebaa Iv Eco Dawn fe Mun D Sak Output Int Cuna 0 amr ie we CauniLaii Kal CED EEN DAS Stace Hiius LEDa E igit m OG n m NC m m m gt lt Cooling System Safeties Settings Figure I 7 Software Front Panel shot of the test station software front panel along with the location of the controls and indicators for each subsystem The block diagram is a graphical representation of the control software It is the interface used to write and modify the control logic The only time test station users should access and make changes to the block diagram is 1f they want to modify the test station control software See Sections IV A 2 Block Diagram and IV C Modifying Software G Safety Control System There are two different types of safeties on the test station high level software independent safeties smoke alarms H detector and ventilation fan alarm and low level software initiated safeties low cell voltage high fuel cell temperature etc There Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description are also two different types of test station shutdowns emergency shutdown and nor
87. jects engulfed by a hydrogen flame tend to heat faster However the lower radiation of heat from the flame means that there is less heat transferred to objects or people outside the flame The heat of combustion of hydrogen per unit weight is higher than any other material but hydrogen has a relatively low heat of combustion per unit volume Thus the combustion of a given volume of hydrogen will release less energy than the same volume of either natural gas or gasoline Hydrogen Embrittlement and Material Compatibility Prolonged exposure of some high strength steels to hydrogen can cause them to lose their strength eventually leading to failure This is known as hydrogen embrittlement and occurs when hydrogen permeates into the lattice structure of the material Sensitivity to hydrogen embrittlement is influenced by numerous parameters including plastic deformation cyclic loading hydrogen purity temperature and pressure Hydrogen embrittlement is a particular issue for ferritic steels and occurs at ambient temperatures and elevated pressures The problem is exacerbated when the steel is subjected to mechanical stresses The processes take place on freshly generated metallic surfaces that are likely to form at surface defects or other stress raisers as a result of stress induced local plastic deformation processes Suitable metals for gaseous hydrogen service include austenitic stainless steel with greater than 7 nickel such as 304 304L
88. ll be maintained using the HIGH and Low DEAD BANDS selected in the COOLING settings tab control To allow for automated control over the heating and cooling of the stack two separate temperature ranges and algorithms are used When heating the heaters are controlled using pulse width modulation The heating temperature setpoint is calculated as the SET POINT minus the Low DEAD BAND minus 2 C and will be referred to as the calculated heating setpoint temperature When the temperature is below the calculated setpoint minus the Low DEAD BAND the heaters are on when it is above the calculated setpoint plus the HIGH DEAD BAND the heaters are off When the temperature is between the Low and HiGH DEAD BAND temperatures the heaters are pulsed Pulsing of the heaters depends on the calculated setpoint the two DEAD BANDS and the PULSE PERIOD When cooling the stack the fans are on when the temperature exceeds the value of the SET POINT plus the HIGH DEAD BAND and the fans are off when the temperature is below the value of the SET POINT minus the Low DEAD BAND The pump can be directly controlled using the PUMP control in the COOLING system control box However the TEMP CONTROL button does not provide direct control over the heaters or fans When the TEMP CONTROL button is enabled the temperature of the water circulation system at the point where TFC is measured determines whether the heaters or fans are on A float switch is used to control filling o
89. lugged into the UPS and the UPS should remain plugged into the wall outlet at all times 67 e Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety Chapter VII Safety In addition to the safety information given in this manual please also read the safety information provided in the manufacturers literature provided with the test station as Appendix B to this manual We also provide a list of recommended reading material at the end of this chapter that covers hydrogen system safety as well as proper hydrogen gas system design and operation A Safety Orientation This chapter addresses safety issues that all personnel working with the test station need to be aware of The system while designed for maximum safety and fully compliant with all applicable safety codes and regulations can be hazardous if not operated correctly The primary potential hazards associated with the test station include e high pressure gas accidents fire and electric shock After studying this section of the Operations and Maintenance Manual system operators should understand these hazards and be prepared to respond to any foreseeable hazardous situation that may arise in a manner that will protect personnel in the vicinity while also avoiding or minimizing harm to the facility and equipment WARNING Never work at the fuel cell test station alone At least two people should be in the room at all times when the test
90. mal shutdown The test station is designed to be intrinsically safe i e the system components have been selected so that if power is lost for any reason all contactors solenoid valves and relays will revert to a safe condition 1 High Level Software Independent Faults Faults that could create a hazardous condition if the test station were to continue operating are treated as high level faults Power is supplied to the test station control system via circuit 1 15 A 120 VAC on the UPS This power is supplied to the 5 VDC 24 VDC and 15 VDC power supplies which in turn provide power to the transducers relays solenoids and other components on the test station This AC circuit also provides switched AC power to the test station The 120 VAC power from circuit 71 is controlled by the high level safety system If the EMERGENCY STOP button is pressed or a high level safety alarm is activated H2 detector smoke alarm vent alarm power from this circuit will be disconnected and all contactors solenoid valves relays and other test station components will revert to a safe unpowered state In addition AC power supplied to the 5 VDC and 24 VDC power supplies is routed through a watchdog timer relay This watchdog timer is used to make sure that the backplanes and test station components solenoid valves relays etc are only powered when the test station is running Consequently the LabVIEW program must be running and toggling the wat
91. ment V A Ww Frequency Hz No of Pulses ZE Duty Cycle 4 Slew Rate us EO l Slew Mode Pulse Periods Frequency Duty Cycle Figure IV 8 Front Panel Load Settings When Pulsing the Load Figure IV 9 displays the setting for performing a polarization IV curve During an IV curve the current is varied while the cell voltages and other variables are monitored The IV curve should not be taken to a current that results in mass transport limitation or in any individual cell voltage being less than 500 mV WARNING The OHMIC END CURRENT should never be great enough to reduce the lowest cell voltage below 500mV or result in mass transport limitation The SAFETIES should always be enabled while IV curves are being conducted 32 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Cooling Load Safety Foie test Range BLAU ALERTES Mode Mea nsi Constant Pulsing IV Curve Driving Cycle Increment in ct Region 05 Amps Activation End Current 60 Amps Increment in Ohmic Region Sol Amps Stan 1v cure Ohmic End Current s20 Amps Time at each Step 50 Figure IV 9 Front Panel Load Settings When Running an IV Curve The IV CURVE settings are split into two regions activation and ohmic resistance The ACTIVATION END CURRENT should be set to a value just beyond the activation region The INCREMENT IN ACT REGION determines the current
92. meter Controller Matheson Tri Gas 3122 350 High Pressure Regulator Matheson Tri Gas 3702 Low Pressure Regulator Omega PX603 Pressure Transducer ASCO 8262G208 Solenoid Valve ASCO 8210G93 Purge Solenoid Valve Swagelok CPA Series Check Valve Pressure Relief TF Series Tee Type Removable Filter Air System Omega PX4202 Pressure Transducer Calibration Certificate MKS Type 1179A24CS1BV Mass Flo Controller MKS Type 1559A 200L SV Mass Flo Controller ASCO 8262G230 Solenoid Valve Wilkerson B08 Filter Regulator Swagelok SS 4CPA2 DG 50 Check Valve Swagelok CA Series Check Valve Pressure Relief Water System Pathfinder Conductivity Transmitter Model CT 1000 pt Sensorex Conductivity Probe Omegalux FGH Flexible Heating Tape Omegalux VPT 107 120 Immersion Heater March AC 2CP MD Pump ASCO 8262G86 Solenoid Valve McMillan 101 8 Flo Sensor Water Filter Changing Instructions Swagelok CPA Series Check Valve Pressure Relief Electrical System Dynaload RBL488 Electronic Load Tripp Lite SmartPro 3000 Rack Mount UPS Monitoring and Control Hardware National Instruments SSR Modules and Backplanes National Instruments SC 2056 Cable Adapter PCI 6711 6713 AO DAQ Board National Instruments SCB 68 68 Pin Shielded Connector Block AO Cable Adapter 5B03 5B04 Backplanes Operations and Maintenance Manual Appendix B PEM Fuel Cell Test Station Component Manuals and Spec Sheets Omron S82J Switching Power Supply Power One HBB15 1 5A 1
93. n 30 seconds a lesser but still significant leak may be present If all cell voltages stay above 800 mV for longer than 30 seconds the cells do not have a significant cross leak Operations and Maintenance Manual Chapter V PEM Fuel Cell Test Station Troubleshooting WARNING Notify the Schatz Energy Research Center if a cross leak is suspected 60 Operations and Maintenance Manual Chapter VI PEM Fuel Cell Test Station System Maintenance Chapter VI System Maintenance The purpose of this chapter is to explain routine preventative maintenance procedures that should be carried out in order to avoid test station malfunctions and ensure a long safe operating lifespan for the test station A Air Hydrogen and Water Systems Maintenance Common maintenance tasks for all three subsystems include visual inspections pressure relief valve setpoint checks and system leak checks Other procedures are for specific tasks such as deionization cartridge changeout hydrogen filter cleaning and replacement and hydrogen vent line purging 1 Visual Inspection The operator should make a periodic visual inspection of all system components including gauges hoses and vent line exits The components should be inspected for cleanliness and integrity in order to identify potential failures Vent line inspection is extremely important during the winter months to ensure ice or snow does not block the outlet of the vent lines and inhibit gas flow
94. n air the hydrogen alarm will initiate a high level shutdown of the fuel cell test station and an audible alarm The hydrogen gas alarm is discussed further in Chapter V Troubleshooting Ventilation Flow Alarm A differential pressure flow transducer diaphragm switch will indicate if there is a loss of ventilation airflow for the test station area If a loss of ventilation airflow occurs the diaphragm switch will initiate a high level shutdown of the fuel cell test station and an audible alarm The ventilation flow alarm is discussed further in Chapter V Troubleshooting Watchdog Timer The control system for the fuel cell test station is equipped with a watchdog timer If the computer locks up or a software error occurs that inhibits proper operation of the system control functions the watchdog timer will cut 5 VDC power to the backplanes and 24 VDC power to the test station components This will close all solenoid valves turn off all test station components and place the test station in a safe state The watchdog timer is discussed further in the Safety Control System section of Chapter I 1 Properties of Hydrogen Gas Hydrogen has an undeserved reputation as a highly dangerous substance In reality in some situations it can be safer to work with hydrogen than with other fuels we commonly use such as gasoline methane natural gas and propane in other situations it can be more hazardous Therefore prior to operating the system per
95. n the front panel 3 You will be prompted to select through the menus which stack you are operating Figure IV 17 displays the dialog box for determining the stack that you want to test Click on Stacks and scroll down the menu to either select an existing stack or NEW STACK for a stack that has not previously been tested Would you like to change the data file Use the Menu Bar above to Select a Stack Figure IV 17 Dialog for choosing a stack to test 4 Enter the stack parameters in the dialog box displayed in Figure IV 18 These stack parameters are included in the data file Enter the comments to be included in the data file Stack Name BSERC FC Cell Area 2 300 cm 2 Number Of Cells Number Of Vtaps 4 4 Proton Exchange Membrane I Platinum Loading 10 30 mg cm 2 Other Comments BAdd your comments Figure IV 18 Dialog for setting the stack parameters 5 After entering the stack parameters a dialog box will appear to prompt you to change the data file If you would like to change the data file refer to the Software Modifications section of this chapter If you will not be changing the data file select NO You will then be prompted to press the BACKPLANE START button Press the BACKPLANE START button on the Safety Tray Panel and THEN press the dialog s OK button WARNING If you press the BACKPLANE START button after clearing out the BACKPLANE START dialog box bad data will be written
96. nce 2 Usethe Testing Alarm procedures on page 4 in the Smoke Alarm manual to trigger the smoke alarm 3 After the smoke alarm triggers a hardware shutdown should occur and the Safety Tray siren should alarm 4 Silence the alarm by pressing the SIREN BYPASS button on the Safety Tray front panel 5 When the Smoke alarm stops triggering press the SAFETY ENABLE button on the front panel of the Safety Tray Press the BACKPLANE START button on the front panel of the Safety Tray 7 Youare now ready to resume normal fuel cell testing 2 Ventilation Flow Transducer The Ventilation Flow Transducer will normally require no special maintenance and should not be serviced It is recommended that the transducer be tested annually with the test bench running To test the transducer Use the appropriate Startup Procedures outlined in Chapter IV to get the test station online 2 Disconnect the low pressure hose from the ventilation flow switch 3 After the switch triggers a hardware shutdown should occur and the Safety Tray siren should alarm 4 Silence the alarm by pressing the SIREN BYPASS button on the Safety Tray front panel 5 Reconnect the low pressure hose to the ventilation flow switch 6 When the switch stops triggering press the SAFETY ENABLE button on the front panel of the Safety Tray 7 Press the BACKPLANE START button on the front panel of the Safety Tray 8 Youare now ready to resume normal fuel cell t
97. nd e ur tT M D ees 6 Fase L6 DAQ Panel sono bo UN CARD dS MU MENU D eae RUM 7 Figure Il 7 Software Front Panel eos en deter rte ene RR E ERES ASK I ERE E patS 8 Figure III 1 Location of System Connections 2 00 0 eeseeeseeeeeneeeesneeeeeneeceeneeeesneeeesnneeess 14 Figure III 2 Air Hydrogen and Water Supply and Exhaust Lines 15 Figure III 3 Rear View of Stack Showing Van 16 Figure III 4 Front Panel of the Safety Tray cccsssssccccssssecnecsssssteccssssnesesssnecseonses 19 Figure IV 1 Software Front Panel esee iiti eto te ne o e EEN 22 Figure IV 2 Front Panel Air Controls Indicators and Settmgs cee eeesseeeeereeeeeeeees 23 Figure IV 3 Front Panel Hydrogen Controls Indicators and Settings 25 Figure IV 4 Front Panel Cooling Controls Indicators and Settings 26 Figure IV 5 Front Panel Fuel Cell Indicators i tdseqond ocio tex qut aS ESRR YR Nen S ARKRRRATS 28 Figure IV 6 Front Panel Safety Controls and Settings sees 30 Figure IV 7 Front Panel Eeer dee 31 Figure IV 8 Front Panel Load Settings When Pulsing the Load 32 Figure IV 9 Front Panel Load Settings When Running an IV Curve 33 Figure IV 10 Front Panel File Settings sos e Rt e e op ean uir ates ae de 34 Figure IV 11 Front Panel E RE 33 Figure IV 12 Front Panel Cell Voltage Plots
98. nsducer to the test station complete the following tasks 1 Connect the transducer power supply to the appropriate bus 120 VAC 24 VDC or 15 VDC 50 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation 2 Connect the analog output of the transducer to the desired spare channel on one of the analog input backplanes and plug in the appropriate 5B analog signal conditioning module In software open the SCALE DATA subroutine Add the appropriate scaling factors for the transducer using the SPARE CHANNEL global variable for the channel number that the instrument is connected to Run the test station software 6 Add the new instrument to the data file following the MANIPULATING DATA FILES 5 procedures provided in this section On the ADDITIONAL CHANNELS frame of the DYNAMIC GRAPHING tab control the scaled value produced by the transducer should be displayed on the appropriate indicator It is not recommended that you change the name of the channel from SPARE Changing these names would eventually cause the user to forget which channels correspond to which indicators without looking at the code To help the user remember what the data represents when the program is not running place a text note next to the indicator describing the data Modifying the Graphs To change the data displayed in either the BP vs FLow graph or the IV CURVE l 2 Open the Block Di
99. nterface used to write and modify the control logic The only time test station users should access and make changes to the block diagram is if they want to modify the test station control software 1 Front Panel The front panel is divided into eight areas air hydrogen and cooling system control boxes stack monitoring display safeties control box dynamic graphing tab control settings tab control configurable parameters and error status Figure IV 1 includes a screen shot of the test station software front panel along with the location of the controls and indicators for each subsection The controls and indicators within each area are described below Each test station system and its respective settings are presented together 21 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Hydrogen System Air System Stack Monitoring f fun ENI art ie 3 Dynamic Graphing RA S E 15 3 3 Sea fm ren Des x ee z n RE i 2 A 3 D a pt An S H afas BERE n vus reser COOLING wn I is fii Output D 5 3 Va Vnlg TR BERE rs E Alius eet Vos rarus ci Bes timar Ss a a E Teemu ze SE 2 Du RUAL bs v 1 traccun tiv PS IS ef muc zx 0 El BENI E ps C Wa Fil E E ei a E Shack Hais EE E wm B ni 5 RE s DR oec H EIS M EE unen x H D D Zon SA uk fk WR a Cooling System Safeties Settings Figure IV 1 Software Front Panel
100. occurred If the hydrogen detector senses a significant leak 2196 hydrogen in air the H2 SMOKE and FAN LEDs will turn red If one of the two smoke detectors detects smoke the SMOKE and FAN LEDS will turn red If the ventilation flow transducer does not detect an acceptable pressure differential between the hood and the air exhaust trough the FAN LED will turn red 1 Hydrogen Leaks The hydrogen detector consists of a transmitter and sensor The sensor mounted in the hood detects the concentration of hydrogen in air Use the following procedures if a hydrogen alarm is triggered 1 Close the hydrogen cylinder valve 2 Look at the hydrogen detector digital display and determine the percentage of hydrogen in air being detected in the hood 3 Ifthe hydrogen in air percentage is greater than 2 leave the room and notify facility safety personnel 4 Ifthe percentage is between 0 5 and 2 complete a visual inspection of the hydrogen plumbing following the procedures outlined in the Leak Check section of the Maintenance chapter You will not be able to restart the test station and pressurize the system downstream of the H supply solenoid until the concentration decreases below 0 5 5 Ifthe percentage is less than 0 5 leak check the hydrogen plumbing following the procedures outlined in the Leak Check section of the Maintenance chapter You may need to complete several iterations of pressurizing and depressurizing the system unt
101. of Chapter III 6 Perform a valve line up on the test station subsystems as follows WARNING Before opening any valves either manually or remotely from the control software the operator should have a complete understanding of what the normal system response should be If a water gas or air leak is detected or any unexpected system response occurs immediately close the valve and correct the problem a Water Circulation System i Close the water reservoir drain valve ii Open the DI water supply valves iii Open the water throttle valve half way b Air System i Open the air supply valve ii Position the 3 way valve to the desired MFC c Hydrogen System i Close the manual supply delivery purge and cylinder valves ii Open the cylinder valve and check all pressure gauge readings iii Open the delivery valve iv Ventthe line by opening the high pressure vent valve v Open the hydrogen supply manual valve vi Close the hydrogen purge drum drain valve vii Close the hydrogen purge solenoid valve bypass valve 7 The test station is ready for fuel cell testing 43 o Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Normal Startup 1 Check to make sure that the SAFETY STATUS LED is green If the LED is red troubleshoot the high level faults before proceeding 2 Start the test station program by pressing the white arrow in the top left corner of the toolbar o
102. ogen Flame Detect Otis ci e trio Hee caution Na Aa OR RIS Ia OR CANTI 76 qe SM EE 76 o Hearne Protection hak crt dundee dao catt baba nte tbt ttt Staten dts 76 6 Fite Blinket EE TT D Hazard Identification and Response TE l High Pressure Hazards seed eoe Do erae ao oo ee ODE IR o DOR Ud 77 2 Fire and Combustion Hazards sud cscs edere e e P p EE 78 3 Electric Shock Hazards s assets eege eds intei RR Ru 79 iv Operations and Maintenance Manual PEM Fuel Cell Test Station Be Safety Ve EE Tagout Lockout Procedure ausi cer te td ce oti ret Een E o CO RENS RE F Material Safety Data Sheets MSDS uei rinsl cube lagen exigen Nose deua ROO esa cuo eu ets G Additional Informational Resontees ace e ee idt ese eege Appendices Appendix A System Specifications and Drawings A1 Test Station Specifications A2 DAQ Channel I O List A3 Symbolic Subsystem Drawings Appendix B Component Manuals and Spec Sheets included as separate binder Bl Air System Components B2 Hydrogen System Components B3 Water Circulation System Components B4 Electrical System Components B5 Monitoring and Control System Components B6 Safety System Components Appendix C Quick Reference Sheets for Operating Procedures Appendix D Material Safety Data Sheet Operations and Maintenance Manual PEM Fuel Cell Test Station List of Figures Figure I 1 Photo of Test Station Showing Major Componentz 1 Figure 1 5 GENEE Came e ee oe eir aee ur seen ed ou
103. ogic In Section z 40 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Figure IV 16 Display and Shutdown Section of the Block Diagram 41 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation The startup section of the block diagram located to the left of the main while loop is used to step the user through the startup routine when the program is first run The startup routine consists of establishing the settings for the stack being tested configuring the data file contents and supplying power to the backplanes In addition the startup section includes the logic that initializes the front panel controls The subtasks section of the block diagram consists of ten sequential subroutines that perform independent tasks These subtasks are named DATA IO SCALE DATA CALCULATE DATA SAFETY TASK HYDROGEN TASK AIR TASK COOLING TASK LOAD TASK DATALOG and DISPLAY TASK Five arrays of data ANALOG IN DIGITAL IO ANALOG OUT CALCULATE DATA and ERROR are passed through each subtask The subtasks read and write values to these arrays and then pass the data to the next subtask The DATA IO subtask is used to acquire and send data to the backplanes via the DAQ boards and signal conditioning hardware The SCALE DATA subroutine scales the raw analog input data 0 5 VDC signals based on the instrument calibration curves The analog
104. ontains the high level safety relays the electrical system components fuel cell contactor and current shunt and additional electrical hardware Figure III 4 contains a picture of the control panel on the safety tray SAFETY PANEL saret status 7 H SENSOR Figure III 4 Front Panel of the Safety Tray The 15A 120 VAC circuit supplied from the UPS to the Safety Tray circuit 71 can be manually disconnected using the ON OFF switch located on the right hand side of the front panel The Emergency Stop button is in series with the manual disconnect and when pressed will also disconnect the 15A circuit to the safety tray Five LED safety and power indicators are used to display the status of the safety and power circuits The Hz SENSOR SMOKE and VENT indicators display whether one of the high level faults has triggered When no safety faults have occurred all three indicators will be green If the Hz SENSOR trips all three indicators will be red If the SMOKE ALARM trips the SMOKE and VENT indicators will be red If the VENT alarm trips only the VENT indicator will be red If any of these high level faults are triggered the 15A 120VAC circuit supplying power to the Safety Tray will be disconnected 19 Operations and Maintenance Manual Chapter III PEM Fuel Cell Test Station Test Station Hardware Operation However these individual faults do not latch Consequently a latching safety relay and a SAFETY STATUS LED are used to l
105. ontrollers Two mass flow controllers 0 20 slm and 0 200 slm are used to deliver air to the stack If the stack will be operated consistently below 20 slm it is recommended that the 20 slm mass flow controller on the bottom be put in service To change which mass flow controller is used to deliver air to the stack l 2 3 4 5 6 3 Follow hardware procedures given in section III D Change the calibration in AIR settings control tab located on the front panel see the Air System in section IV A 1 The air mass flow controller calibration is set as a linear equation described on the front panel The maximum airflow represents the x variable the maximum control voltage signal represents the y variable and the slope is represented as the maximum voltage signal divided by the full scale flow For example if the mass flow controller is 200 slm and requires a 5 VDC signal to deliver 200 slm the slope m value entered on the front panel should be 5 volts 200 slm or 0 025 volts slm The calibration on the front panel scales both the input and output signals to and from the mass flow controller Neither mass flow controller should require a non zero offset however the software is capable of including an offset if desired Set the fixed flow rate to half of the MFCs full range Open the AIR SUPPLY SOLENOID Check that the analog output to the MFC is approximately 2 5V Close the AIR SUPPLY SOLENOID and reconnect the air inlet line
106. ot causes of the problem Problem Chapter V Troubleshooting Table V 2 Troubleshooting Fuel Cell Stack Failures Symptom Root Cause Anode flooding Humidification cross leak Cathode flooding Voltage rises sharply w air surge oltage decreases during purge and recovers immediately after purge nusually wet purge After purge voltage recovers then decays e after a period of time Water leaks from any of the bottom four stack bolts oltages not stable at normal air stoichiometries 250 300 nusually wet air exhaust d Water leaks from stack or stack bolts High and or fluctuating air pressure 58 Hydrogen delivery system can not provide enough flow during purge Inadequate purge duration and period broken separator or cooling plate Inadequate purge duration and period Loose stack bolts broken separator or cooling plate Inadequate air stoichiometry loss of GDM hydrophobicity Incorrect Airflow Source calibration Broken separator or cooling plate Loose stack bolts Torn humidification membrane e Operations and Maintenance Manual PEM Fuel Cell Test Station Power Section Water collecting in the Air Inlet line when the stack is not being operated Cell does not pass cross leak check Chapter V Troubleshooting Torn humidification membrane Hole or tear in membrane Ges oltage rises when H pressure is removed e Por
107. otify the appropriate safety officer of any discharged partially discharged missing or mislocated fire extinguishers Fire extinguishers at the site should be of type A B C Only Halon fire extinguishers should be used on a fire involving personal clothing The materials from other extinguisher types can cause asphyxiation by cutting off oxygen to a person surrounded by the cloud of chemicals In order to effectively operate a fire extinguisher one should remember P A S S P Pull the pin A Aim the hose at the base of the fire S Squeeze the handle S Sweep the hose back and forth 2 Hydrogen Gas Detection A portable hydrogen gas or combustible gas detector can be used to check for hydrogen leaks at the fuel cell test station Such a device can be a useful diagnostic tool when trying to locate a leak in the hydrogen system plumbing 3 Hydrogen Flame Detection The unique characteristics of a hydrogen fire make it difficult to perceive with the human senses The flame is nearly invisible especially in daylight and perception of the heat from a hydrogen fire doesn t occur until direct contact with the combustion gases A dry corn straw or sage grass broom can be used to detect small hydrogen fires by holding the broom out in front of you while approaching the area where the hydrogen fire is suspected Alternatively a portable UV detector can be used to detect hydrogen fires 4 Safety Glasses Operators should wear safety gla
108. ous or broken separator cooling plates Sniffer indicates H3 in air exhaust Hole or tear in membrane Porous or broken separator cooling plates Loose stack bolts MEA damage Lack of above symptoms e Catalyst contamination e Voltage forced above 1 8 V cell e Water connected to Air or H fittings Restricted voltage rises sharply with air surge with out e Mechanical blockage airflow signs of flooding 2 Cross Leak Check To determine if a cell in the stack has developed a cross leak due to a puncture in the membrane pervious separator cooling plates or loose stack bolts use the following procedures 1 Place the load at open circuit by setting the load to 0 Amps Open the Load Contactor Open the HYDROGEN SUPPLY SOLENOID and supply at least 10 slm air 2 3 Wait until the cell voltages are relatively stable 4 Usethe hydrogen detector to measure the amount of hydrogen present in the air exhaust indication of the presence of hydrogen is satisfactory 5 Remove the air supply by disconnecting the hose from the air inlet fitting 6 Observe the cell voltages over time Ifa cell voltage rapidly decays after removal of the air supply observe which cell crashes first The first cell to crash is usually the cell that has a punctured membrane or is near a cracked graphite plate A rapid decrease in cell voltage is a sign of a significant cross leak If a cell voltage holds strong initially but begins to degrade withi
109. perature Control 12 Chapter III Test Station Hardware Operation ccccccccesscceeeeeneeeeeeeeneeeeeeeeteeeeenenaes 14 A RUG Gell Stack EE 14 B Low Pressure Regulator Adiustment 16 C Hydrogen Cylinder Initial Set up and Exchange 17 D Switching Air Mass Flow Controllets aee ee tete teda ra trt tied ere ets 18 E Air Blower perdtioDis o oot oae arn Cis va dd o ed M c Give Ma Qr dte ped 18 eg EE 19 Chapter IV Test Zetting 2 AS SoftWare Descriptio eeu EE 21 Is CBront Patel ouest oue qas EE 21 PNE Block EEN 38 B Startup and ss e eee Seales oe co e c pie idm eR 42 C Modifying Sotwate eese cce me tto Dese UR De ad Ree DR Rd et 47 l Adding a BlOWGE i deir e i Pm Ee a e pe e qo amass qiiis 47 2 Switching Air Mass Flow Controllers sccccssssccccssssccssssssscssesssetasesses 48 3 Manipulating Data Files scia ced dace t p ERI AR RID 48 4 Connecting a New Tee o oe aide eei e 50 iii Operations and Maintenance Manual PEM Fuel Cell Test Station 5 7 Modifying the e oe oreet etae e eode fei en d ette 5 Chapter V TroubleshoOt mg isset ide oii er ad a SEE I P RE Eo SE Ca RE Ur dad cvs 39 As High Level Faults osea tno eta ct esis tes das otesas Des ED PUT Pasce ittis 53 l Hydrogen Leaks Eeer EE 53 2 e n Sess dero pc 23 3 Fatt Alarm EE 54 B Clearing Safety CN 54 Cr Software Debugging EE 54 DA Low Level Faults aec detecta ate dde bas et ota tinte aded tea 55 EK Fuel Cell Paults aienea
110. re Operation Chapter IV Test Station Software The purpose of this chapter is to instruct test station users in the operation of the front panel a computer interface used to control and monitor the test station and the fuel cell stack This chapter also covers how to make permitted modifications to the test station software and how to perform special testing procedures A Software Description LabVIEW produced by National Instruments Corporation is a programming language used in industrial and laboratory automation To operate maintain and modify the test station software it is necessary to have some understanding of the LabVIEW programming environment It is strongly recommended that any test station operator read the LabVIEW user manual and complete the online tutorials included with the LabVIEW software before modifying the test station software in any way LabVIEW programmers interact with two different interfaces namely the front panel and the block diagram The front panel is the operator interface used to control and monitor the test station A hardware state configurable parameter or safety condition can be manipulated using the controls on the front panel and physical phenomena are measured and displayed using indicators and graphs on the front panel The controls and indicators are organized by test station system and arranged by color The block diagram is a physical representation of the control software It is the i
111. rmal Values for Test Station Operating Variables Normal System Indication Parameter Monitored at Value Range Setpoint stoichiometry front panel 200 300 A Actual stoichiometry front panel 200 400 ir Air inlet pressure front panel 0 50 in WC Air regulator pressure gauge 20 35 psig Cylinder regulator pressure gauge 70 100 psig Hydrogen Low pressure regulated pressure front panel 2 5 psig Water flow rate front panel 1 4 liters min Temperature at fuel cell front panel Setpoint deadband Water Conductivity front panel lt 5 uS Water pressure gauge lt 100 in WC Startup after a High Level Fault l 2 6 Press the SIREN BYPASS button to silence the horn Stop the Test Station program by pressing the software PROGRAM SHUTDOWN button Observe which high level fault caused the shutdown by checking the color of the LEDs on the Safety Tray Refer to the High Level Faults section of the Troubleshooting chapter to handle the fault Press the SAFETY ENABLE button on the front panel of the Safety Tray Ifthe horn goes off again after pressing the Safety Enable button the condition causing the high level fault is still occurring Continue troubleshooting the high level fault until the siren no longer goes off after pressing the SAFETY ENABLE button Follow the Normal Startup Procedures above Normal Shutdown l When finished testing press the software PROG
112. s 1 High Pressure Hazards Any gas can be dangerous to handle at high pressure flammable or not Hazards associated with gas leaks in the high pressure hydrogen system include injury from projectiles associated with a catastrophic failure of high pressure plumbing fire and explosion hazards asphyxiation via oxygen displacement hose whipping gas entrainment in the blood system due to direct contact of a high pressure gas stream with the skin and hearing damage due to a loud noise associated with a high pressure gas system rupture Hydrogen for the fuel cell test station is stored 1n compressed gas cylinders at about 2000 psig when full The cylinder regulator reduces the hydrogen gas pressure to about 100 psig immediately as it leaves the high pressure cylinder The pressure is further reduced to a low level of only 3 to 5 psig before the hydrogen gas reaches the fuel cell Note Only authorized trained personnel should work with compressed gases RESPONSE A hydrogen gas leak or high pressure rupture has the potential for fire and or explosion Rapid response is the best way to prevent or minimize equipment damage and personnel injury If a hydrogen gas system leak or rupture occurs perform the following steps a Shut down the fuel cell test station by pushing the emergency shutdown button on the front panel of the safety tray in the electronics cabinet or by tripping the circuit breaker that provides test station power at the m
113. s ua yow z smeis iis ous H Aayjes O Ce we O OFO mm 49127 Aes N Eee Ho fe ov Gei E Es VS 9QO vC Tem Aejay o l eet San I i e N sgeap yas O O 4 V ds SS eue dyoeg l MIA woss indino jeba o O0 ae o o Jexeolg WSL f 0H Ae jay TANVd INO Ov amod dois 3NV IdM2V8 Ausbau E ul OV Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station g uoisiA23 C0 LT L0 eA 93uou ALI suwu Zo amt jo amp v T AAL Ajayes UES Jo Am DL dois SNOLLNS AON39N3W3 SYO LVSIONI H3APRIG Q31301022Z E YOLOVLNOD TIV13d SNISIM diva NIG SINOYLO313 Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station g uorstA2 yy pourjmour qq wen aal HHN Z0 LI L0 ed Ta SE N3349 e D S 2 D Se CH nan II ow 2 ES o ER aay e ese T 04v N33H9 yma Aan CAT 10109 04 T ue3nqorj Jo AUN ap AV ad MOLVOIGNI a VN St e a c N33HO x iD O LN3A O 34ONS O H Appendix A System Specifications and Drawings Operations and Maintenance Manual PEM Fuel Cell Test Station g uorsiAo 0 auou app TO LI LO Veq avol SINOSLIO3 T3 pourri 42404 JA UEN AR podus At used ania ania HOLOSNNOO NOIO3SNNOO2 YOLOVLNOD 71139 1303 swup ZUM JAMO DC genat Jo AN PLL a
114. s Table IV 2 lists the controls indicators and settings for the hydrogen subsystem Table IV 2 Hydrogen Subsystem Controls Indicators and Settings Controls Indicators Settings H5 Supply H Inlet Pressure psig Purge Enabled H Purge H Flow slm Purge Duration sec Time Till Purge sec Purge Period min Figure IV 3 contains a diagram of the HYDROGEN controls indicators and settings 24 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Cooling File Safety Test HYDROGEN Purge Disabled EA Enabled Duration Hell sec Pernod BO min Pressure CT psi H2 Flow BRI sim Time Till Purge PS sec Figure IV 3 Front Panel Hydrogen Controls Indicators and Settings The H2 SUPPLY button in the HYDROGEN system control box is used to control the supply solenoid valve that is located upstream of the stack The Hydrogen PURGE button controls the purge solenoid valve which is located downstream of the stack When the fuel cell is running under normal operation the supply solenoid is open and the purge solenoid is closed except for purging as described below Because the hydrogen pressure delivered to the stack is regulated opening the purge solenoid valve greatly increases the hydrogen flow through the stack the regulator is trying to maintain the desired delivery pressure while the pressure exiting the hydrogen system is at atmospheric pre
115. sonnel should have a basic understanding of hydrogen gas properties and associated hazards The principal hazard presented by hydrogen systems is the uncontrolled combustion of accidentally released hydrogen For hydrogen to combust two additional elements are required an oxidizer and a source of ignition Hydrogen is combustible over a wide range of concentrations in air and a variety of common physical processes open flames hot surfaces friction electrical spark static discharge can serve as sources of ignition Some important characteristics of hydrogen are discussed in more detail below and Table VII 1 compares some of hydrogen s physical properties with those of methane The NFPA 704 Rating for hydrogen gas is Health 0 Fire 4 Reactivity 0 Special None 69 Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety Table VII 1 Some Physical Properties of Hydrogen and Methane Hydrogen Methane Autoignition temperature 520 C 630 C Heat of combustion lower lie iae vale 120 kJ kg 50 kJ kg Lower flammable limit in air 4 by volume 5 3 by volume Upper flammable limit in air 75 by volume 17 by volume 29 5 by volume Density 20C 100kPa 0 0827 kg m 0 6594 kg m Diffusion coefficient in air 0 61 cm s 0 16 cm s Viscosity 20C 100kPa 8 814 uPa s 11 023 pu Pa s Flame temperature in air 2045 C Minimum ignition energy in air 0 017 mJ 0 274 mJ Stoichiometric mi
116. splays Analog Input channels 48 63 which upon test bench installation have no instruments connected to them When an instrument is added follow the procedures outlined in the Adding an Instrument section of this chapter The data collected will be displayed on the Spare Indicator channel to which the signal was connected V vs Time IV Curve BP vs Flow Additional Channels Spare 48 f10000 0 Spare 56 Hmm Spare 49 10000 0 Spare 57 10000 0 Spare 50 0000 0 Spare 58 10000 0 Spare 51 HEH Spare 59 bro c Spare 52 1000 0 Spare 60 fi0000 0 Spare 53 froo00 0 Spare 61 1000 0 Spare 54 f10000 0 Spare 62 froooo o Spare 55 0000 0 Spare 53 mg Figure IV 13 Front Panel Additional Channels Display Error Status If a low level software initiated fault occurs the cause of the fault will be displayed in the ERROR STATUS region at the top of the front panel shown in Figure IV 14 The bottom red text box displays the low level faults and the top yellow text box displays the warnings Warnings are used to indicate a condition that may lead to a fault There is no way to hide the warnings text box The warnings will disappear when the potentially undesirable condition has ceased The indication of low level faults is latched to ensure that the test bench operator 1s aware that the unsafe condition occurred After a low level fault occurs the system is placed in a safe state and both the error status text box and t
117. sri s o ier ENEE ged a aas 58 Kee e EE 58 zi Cross eak C BOOK ET 59 Chapter VI System unten EE 61 A Air Hydrogen and Water Systems Maintenance sse 61 Ly Misual Inspection oa iso te ror Ee FO Gn NC EE 61 2 Pressure Relief Devices Mo e osa ptis te ee 61 3o Keak Checks de eedem donare tU ne M I 62 4 Valve and Regulator Cross Leak OChecks 63 5 Deionization Cartridge Changeout eei eessen ENEE eegen 63 6 Hydrogen Filter Inspection s Ceca sean toa n ae ba RE datei 64 7 Hydrogen Vent Line PUFPIg o o ah s e wos ee reece 64 B Safety E 64 l Smoke Al arins iie eden ee e e de RR Eae ea ER Ie Seta 64 2 Ventilation Flow Transducer EE 65 OR Ee RRE 65 C Transducer Calibrations iet et re eni Y etu edo Ya eva ea EOS TS 66 D Control and Monitoring Hardware 66 1 Check Integrity and Condition of Visible Wiring eee 66 2 GED Components Clean NEE 66 3 Uninterruptible Power Supply UPS eue dan tono nnno dentato o idee Sarees 67 Chapter VIE Safety osos eei ub cedo etes es os Wey cas Yoon LR ede Duae eoe m da 68 As Sale v ATIC TIAN esses SA e tne SAY cals asa e os a E i aa e me bc etes 68 B Test Station Sately BOabufes ones m eoo icd s e ade Mana de e dis 68 l Properties of Hydrogen Gas iss cassis iuicte sete vam rien oe XE LI OR RA YEAR 69 2 Handling Compressed EE T2 C Safety Equipment and Guidelines aiat ct te ea d nad em tome 75 de tere o idet ta D es e aestuat beet ue e Dont 75 2 Hydrogen Gas Detectiofi E 76 3 Hydr
118. sses whenever working in the fuel cell test station lab or performing any operations involving the hydrogen plumbing or hazardous substances In order to ensure proper eye protection is used eyewear should be comfortable fit snugly over the eyes and around the face and not impede the wearer s movement To maintain optimal safety eye protection should be maintained in good condition and be capable of being cleaned and or disinfected 5 Hearing Protection When performing tasks with high pressure gases such as changing out cylinders testing pressure relief devices etc it is a good idea to wear hearing protection If a fitting or 76 e Operations and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety component in the high pressure gas system were to rupture there would be a loud noise capable of causing hearing damage 6 Fire Blanket The fuel cell test station area should be equipped with a fire blanket This can be used to extinguish a fire involving somebody s clothing or hair The appropriate procedure for extinguishing such a fire is to have the victim stop drop and roll on the floor with the blanket wrapped around their body D Hazard Identification and Response The primary potential hazards associated with the test station include e high pressure gas accidents fire and electric shock This section of the O amp M Manual discusses these hazards and the appropriate response to hazardous incident
119. ssure This rapid increase in hydrogen flow while both the supply and purge solenoid valves are open is referred to as purging Automated purging of the stack is controlled in the H2 settings tab control Automatic purging can be enabled or disabled using the DISABLED ENABLED toggle switch Purges last for the time designated by DURATION and the time interval between purges is specified by PERIOD Automatic purging can be overridden using the PURGE control in the HYDROGEN system control box When the purge button is pressed the purge solenoid is opened and remains open until the PURGE button is released Manual purges will not affect the automatic purge sequence will not reset the purge timer or affect the purge period or duration The hydrogen inlet PRESSURE H2 FLOW and TIME TIL PURGE indicators are displayed below the hydrogen controls in the HYDROGEN system control box When the automatic purging is not enabled the TIME TIL PURGE indicator will display 999 seconds Cooling Subsystem and Settings Table IV 3 lists the controls indicators and settings for the cooling subsystem 25 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation Table IV 3 Cooling Subsystem Controls Indicators and Settings Controls Indicators Settings Pump TFC C Set Point Temperature deg C Temp Control Ambient Temp C High Dead Band deg C Therm 2 C Low Dead Band deg C Auto Fill Therm 3
120. t station or its constituent systems they need to understand the importance of maintaining air and water quality and the integrity of all plumbing especially the hydrogen supply and ventilation system A Test Station Requirements 1 Oil Free Compressed Air The test station user must provide a compressed air system including an oil free compressor and an air dryer The air system will deliver dry oil free compressed air to the test bench The supply line is connected to the test station air system at a black handled manual valve located at the back top right of the test station 2 Hydrogen Supply and Venting Hydrogen is supplied to the test station from Compressed Gas Association approved Size 44 cylinders These cylinders are held within the 2 cylinder rack to the right of the test station Only one cylinder of hydrogen is in service at any given time A cylinder exchange procedure is provided in Chapter III Two vent lines are used to vent gas from the hydrogen system One vent line is used for manual venting and pressure relief of the section of piping between the cylinder regulator and the low pressure regulator This section has a nominal pressure of 100 psig with the relief point set at 150 psig and vents outside the building The second line is a low pressure vent line for the low pressure regulator relief valve set at 9 psig and purge gas exiting the hydrogen purge drum This line vents into the hood above the test station 3
121. t the addition of any instrument will not exceed the current limit on the power supply The amount of current produced by the power supply can be measured using a clamp on ammeter 1 Adding a Blower A 24VDC or AC blower can be used as a source of air Use the following procedure for installation and control of the air blower Ensure that the blower has an in line particulate filter to prevent debris from entering the fuel cell stack 1 Perform the hardware procedure given in section IILE 2 In software include the desired code for controlling the blower and make sure that the global variable referenced for controlling the air supply when a blower is used AC OUTLET or BLOWER AIR SUPPLY is correct 3 Onthe front panel of the main test station program select BLOWER as the AIR SOURCE The blower is currently setup to send a fixed voltage when the supply 47 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation 9o Sab pg UE ex 2 solenoid is first opened The voltage to the blower then increases or decreases depending upon the requested airflow and the airflow being measured Set the value of the fixed flow voltage Set the calibration for the airflow transducer Disconnect the air blower from the fuel cell Test the blower with these new settings When you feel confident that the blower is working properly connect the blower to the fuel cell Switching Air Mass Flow C
122. taff as a guide to operation and maintenance of the PEM Fuel Cell Test Station Users of this document will include personnel trained and authorized to use the test station system Document Layout This manual begins with an overall description of the test station in Chapter I System requirements are explained in Chapter II Chapter III guides the user step by step through operation of the test station hardware Chapter IV deals with the test station software Chapter V is dedicated to system troubleshooting Chapter VI addresses system maintenance with emphasis on the use of periodic checklists Chapter VII discusses safety including hazard identification and emergency response procedures Appendix A includes test station specifications and drawings of the systems that make up the test station Appendix B included as a separate binder holds manufacturers product manuals and specification sheets Appendix C consists of quick reference operating instruction sheets Appendix D is a material safety data sheet MSDS for hydrogen Due to the presence of high pressure flammable hydrogen gas and various high and medium voltage electrical equipment the primary potential hazards associated with the test station are high pressure gas accidents fire and electric shock Accordingly ALL operation and maintenance procedures performed on the fuel cell test station should be performed with the utmost care However some procedures described in this manual
123. tation Hardware Operation This chapter provides the procedures needed to prepare the test station for operation Step by step instructions are provided for connecting and removing a fuel cell stack adjusting the low pressure hydrogen regulator initial setup of and exchange of the hydrogen gas cylinder switching air system mass flow controllers changing the air supply from compressed air to blower operation powering the test station and using the data acquisition hardware A Fuel Cell Stack Connection Tygon tubes running from the stainless steel tubing on the air hydrogen and water subsystems are used to supply all liquids and gases to the stack Figure III 1 shows the locations of each of the tubes connected to the appropriate fittings on the right and left endplates of the stack as seen from the front of the stack Figure III 2 shows the connections as seen looking directly at the left and right endplates from the side Figure III 1 Location of System Connections 14 o Operations and Maintenance Manual Chapter III PEM Fuel Cell Test Station Test Station Hardware Operation LEFT ENDPLATE RIGHT ENDPLATE Figure III 2 Air Hydrogen and Water Supply and Exhaust Lines Dry compressed air enters through a 1 2 Tygon hose into the bottom right hand corner of the right endplate Air then passes through the humidification section into the power section and exits through a 1 Tygon hose in the bottom left corner of the left en
124. tch in the water reservoir Water is circulated in a closed loop system to control the temperature of the water entering the humidification section of the fuel cell stack When in the heating mode cartridge heaters placed in the water reservoir and heat tape wrapped around a section of stainless steel tubing are used to heat the DI water before it enters the fuel cell stack When in the cooling mode fans mounted to the heat exchanger are controlled to maintain the desired stack temperature A water flow meter senses water flow and the flow rate can be manually throttled with a valve located upstream of the heat exchanger A water conductivity sensor provides water quality indication Ions introduced by the system are removed by a cartridge deionizing filter located upstream of the fuel cell A pressure relief valve set at 3 psig 83 in WC protects the fuel cell from potential water system overpressure See Figure I 4 for a photo of the water plumbing Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description t id Heat Exchanger DG Figure I 4 Water System D Electrical System Electronic Load and UPS Power is provided to the test bench from a 30A 120 VAC circuit hardwired into the junction box adjacent to the electrical panel on the wall behind the test station Power is routed through a TrippLite SmartPro 3000 uninterruptible power supply unit with a 2 4 kW capacity The UPS moun
125. ted in the electronics cabinet is used to prevent testing interruptions due to power fluctuations or outages Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description One 15A 120 VAC circuit circuit 1 is connected from the UPS to the Safety Tray This circuit is used to supply 120 VAC 24 VDC 5 VDC and 15 VDC to the test station hardware Power from this circuit is disconnected under some safety fault conditions see section G Safety Control System in this chapter for further information A second 15A 120VAC circuit circuit 2 from the UPS provides power directly to the electronic load and the control computer and computer monitor The fuel cell stack is connected to the DynaLoad RBL488 electronic load which is capable of dissipating up to 4kW of power generated by a fuel cell stack The load is mounted in the top of the electronics cabinet beneath the test bench Figure I 5 contains a photograph of the electronics cabinet Figure I 5 Electronics Cabinet E Monitoring and Control Hardware An off the shelf personal computer equipped with DAQ hardware and LabVIEW software is used to monitor and control the test station There are two parts to the data acquisition and signal conditioning system one analog and one digital Analog signals are routed through 5B Series backplanes and optically isolated 5B Series signal conditioning modules to two different DAQ boards in the computer Digit
126. terclockwise 5 Remove the sump carefully so as not to spill water onto the components or wires below Dispose of the water and cartridge and rinse the sump clean The resin cartridge is not hazardous and can be disposed in a regular waste receptacle 6 Remove O ring gasket from sump and wipe groove and O ring gasket clean Place O ring gasket back in place and press O ring down into the groove with two fingers Caution If O ring gasket appears damaged or crimped it should be replaced 7 Place a new cartridge in the sump and screw the sump onto the cap until hand tight Caution Do not overtighten 8 Close the drain valve reconnect the hose to the fuel cell and open the water supply valve 63 Operations and Maintenance Manual Chapter VI PEM Fuel Cell Test Station System Maintenance 9 Start the station software and open the reservoir fill solenoid valve 10 Once full start the circulation pump to remove air from the system 11 Check the cartridge housing for water leaks and tighten the sump if necessary 12 Monitor water conductivity 6 Hydrogen Filter Inspection The hydrogen filter removes debris from the gas stream prior to entering the low pressure regulator Annual inspection of the filter is required to determine if cleaning or replacement of the filter element is necessary Depressurize the hydrogen plumbing as follows 1 Close the hydrogen cylinder valve 2 Open the delivery and supply manual valves 3 Op
127. tions and Maintenance Manual Chapter VII PEM Fuel Cell Test Station Safety Hazards identification First aid measures Fire fighting measures e Accidental release measures Handling and storage e Exposure controls e Personal protective equipment e Physical chemical properties Stability and reactivity e Toxicological information e Ecological information Disposal considerations Transport information Regulatory information G Additional Informational Resources SERC recommends that test station users consult the following documents for more detailed information on working safely with hydrogen National Aeronautics and Space Administration Safety Standards for Hydrogen and Hydrogen Systems International Standards Organization Basic Considerations for the Safety of Hydrogen Systems ISO PDTR 15916 2002 Cracknell R F et al Safety Considerations in Retailing Hydrogen Presented at the 14 World Hydrogen Energy Conference Montreal June 9 13 2002 Hansel J G et al Safety Considerations in the Design of Hydrogen Powered Vehicles International Journal of Hydrogen Energy Vol 18 No 9 pp 783 790 1993 Air Products Corporation Safetygram 4 Gaseous Hydrogen U S Department of Energy Pressure Safety Manual Final Draft December 1993 Compressed Gas Association Documents CGA High Pressure Gas Video CGA G5 Hydrogen CGA G 5 4 Standard for Hydrogen Piping Systems at Consumer Locations CGA S 1 3
128. to the fuel cell Manipulating Data Files The standard data file not the IV curve data file is controlled using a dialog when the test station program starts up To change the data file use the following steps l 2 Start the test station program After selecting which stack is to be tested you will see the prompt displayed in Figure IV 17 Select the blue YES button 48 Operations and Maintenance Manual Chapter IV PEM Fuel Cell Test Station Test Station Software Operation L E m ell L Lm s a Would you like to change the data file 0 Figure IV 17 Data File Configuration Dialog 3 The data file contents dialog displayed in Figure IV 18 should appear The data file contents are presented in four columns The first column contains the HEADERS which are placed in the data file as a row of column headers following the stack comments Any alphanumeric text string can be used as a header The second column ARRAY CHANNEL is used to locate the data in the array The third column is used to specify which array calculated data or analog input the data are stored in The last column specifies the FILE WRITE THRESHOLD If the data have changed by more than the set threshold since the last data file write new values will be written to the data file For example If you would like the operating temperature to be displayed in the data file enter the name of the header TFC in the HEADER column In the A
129. uel Cell Test Station Appendix C Quick Reference Procedures 25 Set the load by entering the desired value into the SETPOINT control box 26 Verify the system parameters are within their normal range of operation using the table on the back of this page Normal Values for Test Station Operating Variables Normal System Indication Parameter Monitored at Value Range Setpoint stoichiometry front panel 200 300 Air Actual stoichiometry front panel 200 400 Air inlet pressure front panel 0 50 in WC Air regulator pressure gauge 20 35 psig B drosed Cylinder regulator pressure gauge 80 100 psig Low pressure regulated pressure front panel 2 5 psig Water flow rate front panel 1 4 liters min Water Temperature at fuel cell front panel Setpoint deadband Conductivity front panel lt 5 uS Water pressure gauge lt 100 in WC Shutdown Procedure iw ee 8 9 10 11 12 13 14 Set the load to 0 Amps Press the PROGRAM SHUTDOWN button Make sure the BACKPLANE POWER LED is red Shut off the DynaLoad Turn the safety tray off Close the DI water valve Disconnect the air line from the fuel cell and cap the air inlet fitting Close the air bleed valve on the right end plate Close the air supply manual valve Close the hydrogen supply manual valve Close the hydrogen cylinder valve Quickly open the vent valve to depressurize back to the cylinder Close t
130. ure is reached replace the access plug and tighten snugly Hydrogen Cylinder Initial Set up and Exchange The following provides step by step instructions for initial cylinder set up and for cylinder exchange The hydrogen cylinder should be exchanged when the cylinder pressure gauge indicates 100 psig Pressure must be left in the cylinder after use to prevent air from entering and contaminating the cylinder For cylinder exchange perform all steps outlined below For initial cylinder set up begin with step 9 l 2 3 10 11 12 Ensure the test station is shut down Close the cylinder valve Close the hydrogen supply manual valve located upstream of the filter and the low pressure regulator Open the delivery valve Slowly open the hydrogen vent valve to depressurize the piping from the cylinder valve to the hydrogen supply valve Pressure indication on both the regulator supply and delivery gauges should drop to 0 psig If pressure does not decrease ensure the blue handled regulator valve is open and the regulator adjustment knob is turned clockwise a few turns When pressures indicate 0 psig close the regulator outlet valve and turn the regulator adjustment knob completely counterclockwise Disconnect the regulator by loosening the CGA nut by turning clockwise Note that hydrogen CGA fittings are reverse threaded clockwise to loosen counter clockwise to tighten Hang the regulator from the support provi
131. valve iii Open the cylinder valve iv Increase pressure to 80 psig using the regulator adjustment v Open the delivery valve vi Quickly vent the line vii Open the supply valve Start the test station program Select the stack that will be tested Enter the stack parameters in the dialog box 10 11 12 13 14 15 16 17 18 Change the data file if desired Press the BACKPLANE START button then press the OK button CLEAR SAFETY FAULT button in software Enter the desired temperature and reservoir values in the COOLING settings box Enable the reservoir AUTO FILL to fill the water system Turn the water pump on and adjust the water throttle valve as necessary Open the air bleed valve on the right endplate Enable the water heaters or cooling fans depending on desired mode Enter air source airflow mode and surge information then open the AIR SUPPLY and connect the air tubing to the stack Enter purge control values in the H settings box Open the H SUPPLY and manually purge by pressing and holding open the PURGE button for a few seconds Select the SAFETY settings box enter values for the low level faults and enable the SAFETIES Once voltages are gt the minimum cell voltage safety setpoint enable the SAFETIES Turn on the load Enter the correct range desired mode and limit type and value information in the LOAD SETTINGS box and press the ENABLE LOAD button Operations and Maintenance Manual PEM F
132. xture in air 9 5 by volume Propensity to Leak The low viscosity and small molecular size of hydrogen gives it a greater propensity to leak than other common gaseous fuels For the same pressure and hole size hydrogen would leak approximately 2 8 times faster than natural gas and 5 1 times faster than propane on a volumetric basis However because the energy density of hydrogen is so much lower than that of methane or propane the energy leakage rate for hydrogen would only be 0 88 times that of methane and 0 61 times that of propane It is nearly impossible unless you use all welded joints to build a gaseous hydrogen plumbing system that is truly leak free However building a system that is as tight as possible and minimizes hydrogen gas leaks is obviously desirable In addition adequate ventilation in the vicinity of the hydrogen system is a must Dispersion Hydrogen is more diffusive and more buoyant than gasoline methane and propane and therefore tends to disperse more rapidly For low momentum gaseous hydrogen leaks buoyancy affects gas motion more significantly than diffusivity For high momentum leaks which are more likely in high pressure systems buoyancy effects are less significant and the direction of the release will determine the gas motion Localized air currents due to wind or ventilation will also affect gas movement At low concentrations the effect of buoyancy becomes less significant because the
133. y solenoid valve that allows automatic shutoff of the hydrogen gas supply to the fuel cell A pressure gauge and a pressure transducer provide local and remote indication of fuel cell pressure Operations and Maintenance Manual Chapter PEM Fuel Cell Test Station Test Station Description When a fuel cell is running on the test station periodic purges of the hydrogen gas remove water accumulated on the anode side of each cell in the stack The purge section of the hydrogen system is located on the outlet of the fuel cell and includes a purge solenoid valve a manual bypass valve and a purge drum The purge drum is mounted to the back right leg of the test bench and has a manual drain valve and vent line During a purge hydrogen gas flow increases rapidly and pushes water from the fuel cell through the purge solenoid valve and into the purge drum Liquid water separates from the gas stream and hydrogen is vented through the low pressure vent line The water accumulates in the drum and should be manually drained to the fuel trench when necessary See Figure I 3 for a photo of the hydrogen delivery plumbing Pressure Transducer Figure I 3 Hydrogen System C Water Circulation System Deionized DI water is connected to the water system at the inlet to a manual valve at the top center of the test bench The addition of water to the water circulation system is accomplished using an automatic solenoid valve that is triggered by a float swi

Operation and Maintenance Manual PEM Fuel Cell Test Station

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