ethanol utilisation in the ge t-58 turbine applied to electric
Contents
1. Two turbines drive the compressor and one drives the load through the rear at 20 500 rpm Specific fuel consumption is 0 64 lb shp h The engine weighs 350 lb 159 kg and produces approximately 1 400 hp IMW With a 3 25 1 reduction gearbox this engine can produce 1 270 lb ft of torque at 6 000 rpm Table 1 presents part of the Type Certificate No H20NM This prescribes conditions and limitations under which T58 GE 100 Table 1 Engine Limits Sea Level Static Standard Day Torque Q Power Turbine Power Speed Gas Generator Speed Turbine N Ne Inlet Temp T s Takeoff T58 GE 100 5 Min 000 ms One Engine Inoperative e e E a O emeses a a a e Starting Allowable Max a NA NA 950 C Sec Overspeed 15 Sec Note 15 105 0 Fuel Aviation Kerosene JP4 or JP5 The facility used to perform the experiments here described was designed and constructed at the Gespi Aeronautica Ltda Sao Jos dos Campos SP in 2008 The schematic diagram of experimental set up is shown in Fig 1 After in Fig 2 full installation with the torque meter detail Torque is a twisting force applied to a shaft A Special torque meter was designed and built to measure the engine power output Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil cH Figure 1 Schematic arrangement of the engine test stand 1 fuel tank 2 T58 eng2. measure analysis and report generation applications A LabVIEW program 1s also referred as virtual instruments Virtual instruments are structured as follows 1 The control or user interface of virtual instruments is known as the front panel The front panel simulates the panel of a physical instrument 2 Instructions that are given to the virtual instrument are in the form of a block diagram 3 Virtual instruments can be used as a top level program or as a subprogram of another program e Front Panel The user interface of VI looks like an instrument Figure 4 This user interface is known as the front panel e Block Diagram With the block diagram you can construct a block diagram that wires together objects that send or receive data perform specific functions and control the flow of execution e Icon and Connector An icon is either the pictorial or the textual representation of the purpose of the Virtual Instrument or its terminals A connector is a set of terminals that correspond to the sub Virtual Instrument controls and indicators The user interface of the developed software is shown in Fig 4 i Relatorios Informa es do Teste Grafico Conjunto Grafico NG NF T5 AM Grafico T2 Stator Vane Postion Grafico Fuel Param Grafico Eng Gil Param GraficoP3 T3 Analise 1300 0 NG NF 1200 0 T2 1100 0 TS Fuel Flow FCU Fuel Outlet Press Pump Fuel Press Stator Vane Position Eng Oi Temp Eng Oil Disc
3. Figure 7 Stator Vanes Angle T58 GE 100 Ethanol and Kerosene Fuel Time ms 6 CONCLUSION All gas turbines whether they are aero engines or land based industrial units share the same basic aerothermodynamic cycle and have the same components in the core design This means interchanged possibility between both However there are several tecnological different demands Aero engines only operate at full load for a small percentage of time compared to industrial units which are more commonly expected to operate at continuous full load year after year Also in an aero engine weight has also been a major concern not just for the engine components themselves but the amount of fuel Landbased systems do not have those same weight concerns This has led to several differences between the design of the two types of engines The most obvious is that weight the core engine for a 44 MW LM6000 weighs 7 2 tons compared to 67 tons for a 32 MW Robb 2008 Until now preliminaries tests indicate that it 1s possible to obtain safety and steady operation with ethanol fuel in T58 GE 100 Start up occurred without problems and operation is quite good Temperature Inlet Turbine is lower than kerosene It is somehow good and at the same time somehow bad Good because it reduces the stress in material and bad once that yield lower torque as well Further and detailed tests are still necessary in order to conclude this work 8 REFERENCES Ashby M Simpson J
4. Singh A Ferguson E and Frontera M Intelligent Engine Systems Work Element 1 3 Sub System Health Management National Aeronautics and Space Administration Glenn Research Center NASA CR 2005 213965 October 2005 Aviadvigatel http www pmz ru eng products gtu for stations Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil LabVIEW 2003 LabVIEW 7 Express User Manual National Instruments April 2003 Langston L S Flight and Light Mechanical Engineering Power May 2000 Robb D Aero Vs Industrial Turbomachinery International FindArticles com 13 Aug 2009 http findarticles com p articles mi_qa5385 is_200801 ai_n25138845 Jan Feb 2008 Technical Manual Turboshaft Engine Model T58 GE 5 T58 GE 100 1 April 1985 Williams R H and Larson E D Aero Derivative Turbines for Stationary Power Ann Rev Energy 13 429 89 1988 9 RESPONSIBILITY NOTICE The authors are the only responsible for the printed material included in this paper
5. is now extracting enough work to keep the compressor at a constant speed without the help of the starter The starter does not cutout at this point 5 More fuel is added accelerating the engine to idle speed The starter assists through a portion of this acceleration to reduce the time to idle In the present work the following procedure was adopted 1 Ethanol had never ever been utilized as fuel in this start up turbine Safety procedure demands start up with kerosene fuel After all ethanol can be used 2 Start up with kerosene the engine remained in idle regimes within 5 minutes Engine was accelerated until flight conditions remained in this condition for more 5 minutes Subsequently the engine returned to idle condition which maintained it during 30 minutes Cycle completed to kerosene fuel Data acquired 3 After the engine had worked with kerosene the engine was cut off After 15 minutes it was switched off 4 Then one new starter was made At this time the fuel utilized was ethanol straight 100 The engine started up normally and the operation remained stable until the cycle was completed 5 Data acquired in both cycle were compared through time synchronization Among some of the things that could be wrong during start are 1 Too much fuel entrance during start hot start 2 Too little fuel entrance during start hung start 3 The start valve fails to close when the starter was released 4 Oil pressure Hyd pressure f
6. lower turbine inlet temperatures However some applications do not need all the power and someone have spreadsheets that tell them that if they are able to produce slightly less power and to prolong unit operation before shutting down for a maintenance outage they will actually save money and increase profits in the long run Turbine Inlet Temperature was a bit lower to ethanol cycle compared to kerosene in about 7 Although the peak of the starter was lowered it was still high enough to start it engine ENGINE RUNNING ETHANOL VS KEROSENE TEMPERATURE T5 STARTER THRU IDLE a00 E50 BOO 750 5 E 700 J 650 ih 600 i 550 F 500 W 450 T5 C 400 si T5 KEROSENE S00 T5 ETHAN OL 250 200 130 25000 a0000 35000 40000 44000 50000 55000 Spoon ESODO TD TS000 TIME milliseconds Figure 6 T turbine inlet temperature T58 GE 100 Ethanol and Kerosene Fuel Time ms 3 Stator Vanes Compressor stalls Although a compressor stall could not be reproduced on the test bench with mistuned settings a smooth sound indicates that the compressor is in a normal operation A compressor stall can be described as an imbalance between the two vector quantities inlet velocity and compressor rotational speed Compressor stalls occur when the compressor blades angle of attack exceeds the critical angle of attack At this point smooth airflow is interrupted and turbulence is created with pressure flu
7. CU B4 5 ENGINE OIL SCAV BEARING 4 5 FCU FUEL DISCH PRESS FP PUMP FUEL PRESS P3 PRESSURE OUTLET COMPRESSOR Figure 3 Instrumentation position NG indicator NG represents the rotational speed of the low pressure compressor and it is presented on the indicator as a percentage of the design r p m After the start the speed of the low pressure compressor is governed by the NG turbine wheel The NG turbine wheel is connected to the low pressure compressor through a concentric shaft NF indicator NF represents the rotational speed of the high pressure compressor and it is presented on the indicator as a percentage of the design r p m The high pressure compressor 1s governed by the NF turbine wheel The NF turbine wheel is connected to the high pressure compressor through a concentric shaft Additional information can be obtained in the manual Technical Manual 1985 Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil The voltage output of all sensors and transducers were adjusted to provide a range output equals 1 5 volts These signals were monitored through a graphical software developed by National Instruments the LabVIEW software LabVIEW 2003 This is a general purpose programming system whose programs are built in a block diagram form LabVIEW program contains extensive library of functions library for data acquisition instrument control
8. Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil ETHANOL UTILISATION IN THE GE T 58 TURBINE APPLIED TO ELECTRIC POWER GENERATION Debaalbeck Borges da Costa Gespi Aeronautica Ltda Sao Jos dos Campos SP debaalbeck gespi com br Cristiane A Martins Instituto Tecnol gico de Aeronautica Sao Jos dos Campos SP cmartins ita br Pedro Teixeira Lacava Instituto Tecnol gico de Aeronautica Sao Jos dos Campos SP placava ita br Abstract The General Eletric T58 engine is a free shaft axial flow gas turbine It was designed to power jet helicopters in the 50s Since then it has been used in a number of military helicopter aplications such as the tandem rotor CH 46 Sea Kinght After more than 50 year sit is clear that there are several T58 out of service Sometimes these engines are still in good condition considering land based operation Flight safety demands are much more restrit On other hand ethanol seems to have an important role considering CO2 emission balance This work presents the potentiality of ethanol utilisation as fuel in aeronautics turbine engines out of service for the purpose of generating eletric power Experimental prelimanary tests indicated economic viability and it was also estimated power turbine operation up to 18 000 hours until the first maitanence This is one indicative of the high reliability of the ae
9. TER THRU IDLE 300 FUEL FLOVAETHANOL BJ Fuel Flow Lbs hr 100 30000 35000 40000 45000 S000 Son Emig 65000 70000 75000 TIME milliseconds Figure 5 Fuel Flow Ethanol and kerosene time ms Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil 2 Engine temperature limitations The highest temperature in any turbine engine occurs at the turbine inlet Turbine inlet temperature is therefore usually the limiting factor in turbine engine operation This is due to the temperature in the combustor where the flame presence is higher and in many cases much highe then the turbine inlet temperature which is the reference T5 turbine inlet temperature Fig 6 shows the turbine inlet temperature T5 with ethanol and kerosene operation It is one of the principal variables in turbine engine This temperature determines the highest temperature inside the machine Generally higher turbine inlet temperatures increase the net work output of the cycle and improve the cycle efficiency Measurements show a decrease in temperature with ethanol operation Leading the maximum turbine inlet temperature to lower value s than the unit is rated and because of the thermal stresses reduction at the lower temperatures the parts lives are anticipated to be longer Of course the power output of the unit will be lowered at
10. ails to rise and finally 5 EGT fails to rise w 1 20 sec of placing the fuel control lever on Even with ethanol operation these 5 events previously described did not occur 3 RESULTS AND DISCUSSIONS Early considerations should be presented when the main idea is to find an alternative to apply the old aero engine turbine There are some manufactured characteristics not so ideal for power plant application Aero engines turbines units are lightweight and compact but it has no large capacities 30 to 35 MW in maximums mainly when compared with heavy duty machines designed for stationary applications which capacity in large sizes change of 70 to 135 MW Heavy duty are suited for combined operations because the turbine exhaust gases are relatively hot 593 C On the contrary aero engine turbines are poor candidates for combined cycle applications since the turbine exhaust gases are not especially hot Williams and Larson 1988 A gas turbine unit for power generation or a turbo shaft engine for production of thrust primarily consists of a compressor combustion chamber and a turbine As the air passes through the compressor experiences an increased in pressure After that the air is fed to the combustion chamber leading to one increase in temperature This high pressure and temperature gas is then passed through the turbine where it is expanded and the required power is obtained To Operate properly an engine must be correctly adjusted H
11. and 3600 for 60 Hz systems Development of the turbine applications to flight and to light power plants started at the same time History registers indicate that the first jet powered aircraft flashed across the skies above the Baltic Sea to start jet Age on August 27 1939 Hitller s war launched the jet Age with the gas turbine powered Heinkel He 178 Von Ohain was responsible for that At the same time some kilometers from Germany in 1939 one Swiss company completed the development of the first modern land based gas turbine It was installed at Neuchatel in the Swiss Alpine foothills to power a 4 megawatt electrical generator for backup power Langston 2000 Gas turbine power stations GTPS have been recently widespread in power engineering of foreign countries For example in Russia it had been widely used There electro generators of gas turbine and electric power station gas turbines were developed by Aviadvigatel on the basis of PS 90A engine The engine is responsible to provide power to the most modern Russian aircrafts 1 96 300 Tu 204 Tu 214 and even to VIP aircraft for the President of the Russian Federation Gas turbine unit models developed until now were GTU 2 5P 2 5 MW GTU 4P 4 MW and GTU 6P 6 MW Aviadvigatel 2009 The common fuel is natural gas Another kind of the gas turbine power generation is the gas turbine mobile units These units in general are used as the main electric power source for industrial and domesti
12. c Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil consumers if there is no trunk power network available or an emergency power supply for peak loads in the presence of trunk mains Motor Sich PAES 2500 PAES 2500B EG 2500 are some models manufactured by Motor Sich JSC and can provide 2500 kW nominal Sich JSC manual These units can be fed with natural or casing head gas diesel fuel or kerosene The present work will present preliminary tests with an old aircraft turbine General Electric T58 model This is out of service for aeronautics application This unit was modified to accept ethanol as fuel The main intention is for electric power application The idea is to transform this compact aero engine in one ethanol fueled compact gas turbine for small power stations 2 2 EXPERIMENTAL APPARATUS AND INSTRUMENTATION Tests have been conducted on a General Electric T58 free shaft axial flow gas turbine The engine 1s a free turbine engine no mechanical connection between the gas producer turbine and the power turbine The power turbine is gas coupled to the gas producer turbine by the combustion gases The compressor has 10 stages with variable inlet guide vanes and variable stators on the first three stages The compression ratio is 8 4 1 it flows approximately 13 7 lb s 11 000 cfm 27 300 rpm The combustion chamber is of an annular design
13. ctuations Compressor stalls cause air flowing into the compressor to slow down and stagnate sometimes reversing direction Although all gas turbine engines are subjected to compressor stalls most models have systems that inhibit these stalls One such system uses variable inlet guide vane VIGV and variable stator vanes which direct the incoming air into the rotor blades at an appropriate angle The GE T58 turbo shaft engines incorporate an automated system that varies the inlet blade angle according to the engine load The Inlet Guide Vane IGV system is one of several features that enable these motors squeeze out every bit of horsepower and boast such exceptional power to weight ratios Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil Variable geometry VG of T58 GE 100 engine consists of the variable inlet guides vanes and the first three of stator vanes stages Figure 7 shows detail about Stator Vane Even with ethanol operation compressor stall was not observed But it is possible to realize that a lower angle is produced by a lower fuel flow ENGINE RUNNING ETHANOL VS KEROSENE DETAIL 2 STATOR VANE STV STARTER THRU II 475 43 0 STV KEROSENE 425 STV ETHANOL 400 375 S a i a 35 0 A 4 325 wy SA 30 0 275 25 0 22 5 20 0 100000 102500 105000 107500 110000 112500 115000 117500 TIME milliseconds
14. ere it is showed some experimental preliminary results of the aero turbine operation with ethanol fuel whose final intention is for power application Ethanol measurements results will be compared with the same values to common fuel aviation kerosene It is impractical to cover specific operational procedures and there are certain operational considerations that are common to all turbine engines They include engine temperature limits hot start compressor stall and flameout Comparing data tests provided of the kerosene cycle and ethanol cycle 3 parameters pay out attention T5 turbine inlet temperature FF Fuel Flow and Stator Vanes Table 2 shows parameter range precision and accuracy of each one Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil Table 2 Parameters characteristics Range Parameter MIN Precision Accuracy MAX fuel flow Ib hr or kg s aa coe coe power mene temperature 0 1000 c 43 1 0 T5 f or c 1 Turbine engine hot hung start A hot start is when the EGT exceeds the safe limit Exhaust gas temperature EGT gauge is an engine operating limit used to monitor overall engine operating conditions Hot starts are caused by too much fuel entering the combustion chamber or insufficient turbine r p m Any time an engine has a hot start refer to the AFM POH or an appropriate maintenance manual for inspect
15. h Press Eng Of Bearings 2P Fae Eng Of Bearing 3P Eng Oil Bearing 4 5 P Speed Selector AM P3 T3 HEH l Filtra 1000 0 a B a a a B a a B a B a al a I lt 100000 0 200000 0 300000 0 Time ms b PROZTOS Banco de Provas Motor GE TS8 100 e MGB SHA TSS Save 20343266434 _20070925_1 txt Gerar Relat rio Figure 4 Front Panel built to T58 GE 100 engine tests 3 METODOLOGY The start up procedure is almost the same in almost every turbine engines Exception is when the engine turns via an electric starter rather than bleed air from an APU or a cross bleed from the other engine The starter procedure is very well described by Ashby et al 2005 included the following 1 Air turbine is powered up and begins turning the engine The torque required to accelerate the engine increases with rotor speed as an effect of the increase in the airflow 2 Before reaching the maximum motoring point fuel is added and the igniter begins to spark Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil 3 Once a flame is sustained the engine begins to accelerate the system High Pressure Turbine HPT is now doing work 4 At the self sustaining point the torque is balanced At any point prior to the self sustaining point disengaging the starter would not allow the engine to achieve idle engine speed HPT
16. ine 3 Main Gear Box for reduction gearbox 4 Dynamometer 5 throttle valve 6 analogy instruments panel 7 data acquisition 8 server computer coupled to engine and MGB monitors Figure 2 Basic setup for turbine measurements a torquemeter detail b side view Proceedings of COBEM 2009 20th International Congress of Mechanical Engineering Copyright 2009 by ABCM November 15 20 2009 Gramado RS Brazil 2 1 INSTRUMENTATION AND TURBINE ENGINE OPERATIONAL CONSIDERATIONS Figure 3 shows the position of the pressure and the temperature sensors around of the engine Engine was instrumented in order to indicate pressure temperature rotation oil pressure oil temperature engine speed exhaust gas temperature and fuel flow At the turbine section there are multiple temperature sensing instruments thermocouples that provide temperature readings in and around it STATOR m Temperature BOP ifpg i iti E Ss VANE i Rotation i nananana Position hS Rees ee ee Pressure EAT gt H X a e b E _ nS mis RAN g h J al X B2 PS gt FF F P FCU TEMPERATURES T2 COMPRESSOR INLET TEMPERATURE ROTATION T3 COMPRESSOR EXIT TEMPERATUTE NG GAS GENERATOR SPEED T5 POWER TURBINE INLET TEMPERATURE NF POWER TURBINE SPEED T OIL ENGINE OIL IN TEMP POSITION PRESSURE STATOR VANE EOP ENGINE OIL DISCH PRESS B2 ENGINE OIL SCAV BEARING 2 FLOW B3 ENGINE OIL SCAV BEARING 3 FF FUEL FLOW BY OUTLET F
17. ion requirements If the engine fails to accelerate to the proper speed after ignition or does not accelerate to idle r p m a hung start occurs A hung start may also be called a false start A hung start may be caused by an insufficient starting power source or fuel control malfunction Fuel control in TS58 GE 100 is a hydromechanical control with 5 engine operating parameters These parameters are 1 Control lever position 2 Gas generator speed Ng 3 Power turbine speed Nf 4 Compressor discharge pressure P3 and 5 Compressor Inlet temperature T2 This information is furnished by a system of sensors throughout the engine which signal the control servo system The servos correlate the various signals and translate them into an input to the control which then meters fuel and positions stator vanes The operation of these 2 variables the amount of fuel supplied to the combustion chamber and the position of stator vanes produces the desired engine output Similar behaviour between both fuels can be observed in Figure 5 This is due to loop control Flow Fuel FF was set through FCU Fuel Control Unit which always tries to increase flow for ethanol operation FCU reading lower rotation and is translated with fuel demands This is an indicative that the fuel system must be calibrated for flow ethanol operation In fact it must be adjusted for at least one addition of the 10 more fuel ENGINE RUNNING ETHANOL VS KEROSENE FUEL FLOW STAR
18. ronautics engines Whole experimental tests were conducted in the Gespi Aeronautics Ltda and more details will be presented here Keywords ethanol aeronautic turbine gas turbine electric plant 1 INTRODUCTION Electric power can be generated in different kinds In fact generator has the necessity of something able to cause the shaft and armature to spin The result is the generation of an electric current The process responsible for the spin shaft and armature can be so different as a hydroelectric turbine wind turbine a nuclear power plant or the same gas turbine power plant Independently all system must be able to turn the copper armature inside the generator and to generate electric current Particularly in a gas turbine power plant fuels are burned to create hot gases which go through a turbine which spins turning the copper armature inside the generator and generating electric current Normally the turbine consists of several stages with each stage consisting of a stationary blade and a rotating blade Stationary blades convert the potential energy of the exhaust product temperature and pressure into kinetic energy velocity and direct the flow onto the rotating blades The rotating blades convert the kinetic energy into forces caused by pressure drop resulting in the rotation of the turbine shaft The turbine shaft is connected to a generator which produces the electrical energy The rotation speed is 3000 rpm for 50 Hz systems
Download Pdf Manuals
Related Search