Xi`an Diesel Study Report - International Sustainable Systems
Contents
1. 7 TABLE 5 POTENTIAL ADJUSTMENT VALUES TO BE USED IN IVE MODEL eee nen eene eene nene nnnnnna 17 TABLE 6 RECOMMENDED ADJUSTMENT VALUES FOR USE IN THE IVE MODEL eere eene 18 TABLE 7 EMISSIONS RESULTS FOR AN AVERAGE FLEET IN SEVERAL CITIES cccccsesssseeececensseeeecessssseeecesesseeeceesensseeees 18 List of Figures FIGURE 1 ISSRC FIELD DILUTION DEVICE cccccccccessssceccessssseeececesnsceeceecessnseeecceessseeceeesssseeeeceeesseeeeceeessseeecesenseeeees 3 FIGURE 2 FLOW DIAGRAM FOR THE OVERALL EMISSIONS TESTING SYSTEM ccsssseesesssssssssssssssssscscesceceseseseseseeesenens 3 FIGURE 3 EXTERIOR OF A TRUCK OUTFITTED FOR EMISSIONS TESTING ccsccccccssssssecceecesssceececeensseseeceessseeecesessneeeees 4 FIGURE 4 WATER BARRELS FOR EMISSIONS TESTING ccccsesssscscccssssscecceecsssseeccceessseeceecessseeecessessaeseeceeessseeeceeentaaeeees 4 FIGURE 5 NUMBER OF VEHICLES BY MODEL YEARS FOR THE TESTED LIGHT DUTY TRUCKS 8 FIGURE 6 EMISSIONS AVERAGED OVER SELECTED MODEL YEARS FOR LIGHT DUTY G KM 8 FIGURE 7 VEHICLES DISTRIBUTION ACCORDING TO EMISSIONS STANDARD esee eene nennen eene nnne 9 FIGURE 8 FTP NORMALIZED EMISSIONS AVERAGED OVER EMISSIONS STANDARDS 10 FIGURE 9 VEHICLES DISTRIBUTION ACCORDING TO WEIGHT ccccssssccceesessseeceecessseeeccceessseeeecessssseeeeeeesssseeceeeensaeeees2. VII Vehicle Sampling Equipment For purposes of these studies a SEMTECH D portable emissions monitor PEM manufactured by Sensors Inc will be used for gaseous emissions This unit employs a flame ionization detector FID to measure THC a Non Dispersive Ultraviolet NDUV analyzer to measure NO and NO a Non Dispersive Infrared NDIR analyzer to measure CO and and an Electrochemical sensor to measure Fuel for the FID is provided via a high pressure canister mounted within the PEM For measuring particulate 26 emissions a Finnish Dekati testing unit will be used to collect second by second particulate emissions data The Dekati test unit makes use of technology that ionizes the particulates and collects them by size A whole exhaust mass flow measurement device will measure the exhaust flow rate based on static and dynamic pressure differentials A partial stream of the exhaust taken from within the mass flow measurement device is routed through the analyzer system at a constant rate of 10 liters per minute The concentration and flow rate data is input to the onboard data logger on a second by second basis Internal filters carbon absorbers and chillers are strategically located in the sample stream to minimize interferences A temperature and humidity measurement device also provides second by second data on the temperature and humidity of the engine intake air Algorithm s in the processing software provide the nec
3. 0 115 3 61 1 58 36 Light Truck 2006 Euro2 328 7 76 0 082 1 12 0 52 397 10 07 0 101 1 39 0 62 37 Light Truck 2004 Euro 1 357 5 63 0 111 1 07 0 53 418 7 01 0 132 1 29 0 62 38 Light Truck 2002 Euro 2 339 5 89 0 116 1 29 0 43 417 7 64 0 148 1 63 0 55 39 Light Truck 2007 Euro2 237 2 90 0 081 0 54 0 97 281 4 00 0 099 0 65 1 12 CO NOx PM co THC CO NOx PM co THC Average of Tests 305 92 5 31 0 17 4 02 1 40 349 95 6 85 0 19 4 55 1 54 90 Confidence Interval 4 10 21 24 9 4 9 22 22 8 Emissions according to Model Year Figure 5 shows the Model Year distribution of the sampled vehicles in this study There were 4 10 of the vehicles in the range of years 1999 2002 9 23 were in the 2002 2005 range and 26 67 were in the 2005 2008 year range Figure 6 shows the CO HC NOx PM and CO emissions from the Light Duty Trucks and emissions for three groupings of model years as can be seen in Figure 5 There is a little overall relation between emissions and model year for the vehicles tested in China CO THC and PM show a decrease trend NOx shows a growing trend in emissions Because the newer vehicles the higher NOx emissions 2009 1999 2002 2005 2005 2008 2008 2002 9 5 9 2007 IIIIYIIIYIIIYY 2006 9 2005 999 99 2004 2003 MODEL YEAR 2002 2001 99 2000 1
4. O flash gps data sample2 155570109 Start Hour 0 v End Hour 23 v CO Column n a lt CO2 Column n a v Satellite Column n a v SaveSettings CALCULATE _ Display Power in Bins Y SAVE RESULTS Time Offset hrs NOx Column n a il Caictiation Hesults Low 1 2 3 4 5 5 7 8 3 10 11 alle Bla 20 Stless 0 01 0 0 01 001 0 06 0 07 0 44 0 62 154 292 592 5553 15 25 375 526 154 023 012 003 0 04 File International Vehicle Emissions Calculation Location Location Fleet InUseTestCycle S Enter the data manually for the 60 Dey Month eL bins and the average velocity in wv v v i September 2004 the Location Page of the IVE model C ooj r Fuel Characteristics Overall Sulfur S Lead Pb Benzene Oxygenate Gasoline moderateipremixed moderate 300 none v moderate 150 05 Overall Sulfur S Diesel moderate v moderate yes r Hour 0 00 all v W Use this hour Driving Characteristics Humidity ee ees VSP Bins Soak Bins 500 0 0 kilometers o o me Temperature E Group 1 Group 2 1 wseg VSPBin2 VSPHn3 VSPBn4 VSPBn5 VSPBn6 VSPBn7 VSPBin8 VSPBn8 VSPBn10 01 01 0B 07 44 e2 154 2 92 vsPq VSPBini12 VSPBini3 VSPBnt4 VSPBni5 VSPBni6 VSPBni7 VSPBn1B VSPBH18 5 20 Average Velocity 55 69 15 25 9 75 5 26 1 54
5. 1 in the section above Max Time 1 seconds When there is a time gap of more than the entry in this column it Jump will discard the data during that time period and pick up when the time gap is over Speed column 9 Mph Indicates which column the velocity is in the GPS text files The GPS units report this information in the column 9 when counting from 0 see Table 1 in the section above Min Time 1 seconds When there is a time gap of less than the entry in this column it will Jump ignore the data during that time period This is to protect against data that is collected at a faster resolution than the GPS reports For example if the GPS is 1 Hz 1 measurement per second but the data is collected at every half second the output file will report a line of data every half second with the information only changing every second In this situation you would want to make sure the Min Time Jump is set to 1 second Altitude 7 Meters Indicates which column the altitude is in the GPS text files The GPS column above units report this information in the column 7 when counting from 0 sea level see Table 1 in the section above Start Rows to 3 integer This is the number of rows after the data starts that is not used in the Skip analysis Usually once the recording begins there are several seconds that do not represent the usual driving pattern Start hour 0 n a Indicates which hour of the day to start the processing according to the time co
6. 12 03 a4 17 2 0 kmhr vseg VSPBn22 VSPBn23 VSPBi24 VSPBin2S VSPBin28 VSPBin29 vsPH VSPBn32 VSPBn33 VSPBin3s4 VSPBin3S VSPBin38 VSPBin38 04 02 vsPH i VSPBin48 VSPBin 49 VSP VSPBin58 VSPBinSa Vehicle 96 Spec Power Distribution 15 8hours 12 hours o Soak Time Figure VIII 2 VE Model User Interface for Entering in Driving Pattern Data 33 Location Various Input Latitude Longitude Altitude Units Location Info 500 m m meters ft feet MM DD YYYY Date 8 28 2002 Units Road Grade positive value is uphill negative number is downhill T M Class Percent AC In Use at 80 F 27 C Fleet File to Use Interpolation File to Use none enter text for one of five options percent of public with AC on vehicle using AC at 80F 27C ambient temperature A blank will be interpreted to use a linear fit for missing hours Overall Lead Pb Sulfur S Benzene Oxygenate Gasoline Enter gasoline related data Diesel Enter diesel related data Description Driving Style Distribution Facility Cycle Distribution Group 1 Vehicles Time Period VSP Bin 1 VSP Bin 2 VSP Bin 3 VSP Bin4 VSPBin5 VSP Bin6 VSP Bin 7 Total Distance or Time Driven Number of Statups Soak Time Distribution Group 1 Vehicles Temperature Relative Humidity 1 hour 2 hour 3 hours 4 hours 6 hours Average Velocity for Group 1 Ve
7. 3 08 3 11 3 14 3 17 Figure 15 NOx Emissions by IVE Bin The main difference compared to previous studies of diesel vehicles is that there is a high emissions rate in bins from 1 00 to 1 05 those bins represented the emissions on vehicles when they are decelerating and one of the possible causes of this behavior as discussed earlier is that the vehicles were being rapidly slowed down when they met speed bumps Figure 16 presents the binned data for particulate matter from the large diesel vehicles The standard form of the emissions curve can still be seen in the data when the erroneous bin classifications are ignored 0 0045 PM 0 004 e 0 0035 f 0 0015 0 001 Ny 00066 ee 0666 dou dom ap e a rn ge E gt pop poper p pep poro 1 00 1 03 1 06 1 09 1 12 1 15 1 18 2 01 2 04 2 07 2 10 2 13 2 16 2 19 3 02 3 05 3 08 3 11 3 14 3 17 g km Ww 4 E S gt Figure 16 PM Emissions by IVE Bin 15 There is a consistent result for the low bins for the PM results they have high emissions in bins from 1 00 to 1 03 probably for the same cause that was already discussed with respect to the CO and NOx Emissions appear to be normal compared to measurements made in other cities VI Emission Comparisons with the IVE Model As noted earlier 39 trucks were successfully tested in Xi an This lim
8. 394 5 99 0 294 12 35 2 33 360 6 97 0 251 10 59 1 87 8 Light Truck 1999 Euro O 298 2 99 0 496 14 63 2 28 296 3 83 0 504 14 99 2 02 9 Light Truck 2005 Euro2 314 4 43 0 116 3 15 1 34 381 5 90 0 146 3 96 1 63 0 Light Truck 2007 Euro2 246 4 51 0 090 1 31 1 29 281 6 11 0 106 1 54 1 40 1 Light Truck 2007 Euro2 266 5 16 0 058 1 39 1 26 305 6 74 0 065 1 56 1 39 2 Light Truck 2005 Euro2 229 4 54 0 085 1 32 1 56 226 5 87 0 080 124 1 33 13 Light Truck 2007 Euro2 329 4 98 0 101 1 68 1 78 381 6 56 0 121 2 00 2 00 14 Light Truck 2002 Euro 1 342 7 04 0 172 7 83 1 32 380 8 56 0 198 8 95 1 44 5 Light Truck 2001 Euro 1 305 5 79 0 080 3 60 2 15 371 7 82 0 098 4 41 2 60 6 Light Truck 2007 Euro2 265 4 52 0 209 2 66 1 27 309 5 66 0 246 3 13 1 47 17 Light Truck 2007 Euro 2 288 4 03 0 122 4 28 1 34 332 5 27 0 146 5 11 1 51 8 Light Truck 2006 Euro2 223 3 91 0 042 1 02 0 63 269 5 17 0 052 1 26 0 75 Light Truck 2005 Euro2 319 10 04 0 075 1 69 1 07 362 12 50 0 086 1 91 1 18 20 Light Truck 2007 Euro 2 283 5 67 0 369 7 16 1 45 338 7 64 0 454 8 82 1 68 21 Light Truck 2002 Euro 1 351 8 78 0 245 13 60 1 58 403 10 09 0 281 15 79 1 80 Table 4 Emission Measurement Results for the Tested Xi an Dies
9. a relationship between emissions and engine standard except for NOx and CO where there is little improvement between Euro 1 and Euro 2 The Euro 1 NOx emissions are lower than the Euro 2 for trucks with the same engine sizes In summary the results show a good relationship between emissions and standard except for NOx It should be noted that just one Euro 0 truck was tested in Xi an Thus this emission rate should not be given much consideration 18 00 16 00 14 00 12 00 10 00 8 00 Emission g km 6 00 4 00 2 00 0 00 14 99 W Euro 0 EH Euro 1 Euro 2 661 7 06 6 02 5 04 3 56 S 3 52 3 5 a 2 02 is 1 78 1 42 1 52 CO CO2 100 NOx THC PM 10 Figure 8 FTP Normalized Emissions Averaged Over Emissions Standards Overall Emissions according to Weight In Figure 9 the Weight distribution of the vehicles tested is shown the range for the overall sample is only 5 tons between 1 to 6 Tons In the range of 1 to 4 tons there were 34 vehicles 23 of them between 2 and 3 tons In the range of 4 to 6 tons there are only 5 vehicles The vehicles were grouped into two weight classes In Figure 10 the results of emissions for these two weight classes are shown The CO THC and PM emissions become lower when the weight increases These can be explained because the heavy vehicles tended to be newer The CO and NOx emissions of the high weight
10. countries as local capacity increases The IVE In Use vehicle emissions study is not designed to fully develop correction factors for the IVE model The original data base used to developed the IVE model correction factors was based on more than 500 vehicle tests each involving three driving cycles carried out at the University of California CE CERT research facility This information was combined with summarizations of thousands of in use vehicle tests provided by the United States Environmental Protection Agency The IVE In Use emissions study discussed in the following section results in emissions data for 40 diesel fueled vehicles Information from 40 vehicles while significant does not provide the range of data for the development of a full range of new emission factors and adjustments Nonetheless the IVE In Use emissions study can be used to make rudimentary adjustments to the IVE model that will certainly improve its performance for developing countries The actual IVE In Use vehicle emissions study makes use of recently developed emissions measurement technology that can be carried on board vehicles while they are driven on urban streets This technology allows emission mass per unit distance to be determined in real driving situations To date this on board emissions measurement 22 technology can be used to measure carbon monoxide carbon dioxide CO2 total hydrocarbons THC and nitrogen oxides NOx A different testi
11. each city 18 Emissions g km 10 00 4 9 00 4 8 00 4 7 00 4 8 Beijing 6 00 E MexicoCity E Istanbul 5 00 1 E SantiagoLD B SantiagoHD 4 00 WSao Paulo E Xi an 3 00 2 00 1 00 4 0 00 1 co HC NOx PM 10 CO2 100 Figure 18 Comparison of Measured Emission in Several Cities Normalized to the FTP LA4 Cycle and Grouped to Similar Size Distributions After studying the results it can be concluded that An emissions from the trucks in Xi an are comparable to those emissions found in vehicles measured in Istanbul However the vehicles measured in Mexico City and Sao Paulo were significantly larger than the Xi an vehicles tested This indicates that the Xi an vehicles are not very fuel efficient for their size HC and NOx emissions of the Xi an vehicles are the highest in these cities although ones tested were not the largest ones PM emissions for Xi an vehicles makes more sense But it 1s higher than Sao Paulo This is especially worrisome considering that the Sao Paulo vehicles were significantly larger than the Xi an vehicles CO emissions are the second greatest of the cities studied They are higher than Beijing vehicles which are bigger in size than Xi an vehicles analysis was also done to derive the rates of emission increase with vehicle use However as was the case with model year comparisons the measurements did not show a trend of vehicle emissions increasing
12. primarily on emission measurements made in the United States and Europe and represent test results from thousands of vehicles It is difficult to know how much weight to give to emission results from only 39 vehicles in Xi an However the confidence limits shown in Table 3 suggest that the averages of the results should be in the ballpark of 30 of the actual values Table 5 shows the actual ratios and the ratios of the measured emission results were modified to be 30 closer to the VE projected values Table 5 Potential Adjustment Values To Be Used in IVE Model NOX Ratio Ewo0 243 206 096 098 100 Overall 561 592 195 096 108 Because of the limited number of tests it is suggested that the values closer to the IVE default values the 30 adjusted values be used until more in use emissions data is collected in Xi an A value of 1 is used in the cases where the 30 adjustment takes the values from less than 1 to greater than 1 17 Table 6 presents the recommended adjustment values for diesel vehicles in Xi an These values should of course be improved as more data is collected Table 6 Recommended Adjustment Values for Use in the IVE model Class CO Ratio VOC Ratio NOx Ratio PM Ratio Euro 0 2 75 1 92 0 48 1 26 Euro 1 7 17 5 39 2 02 0 52 Euro 2 5 74 7 12 2 06 2 17 Overall 5 61 5 92 1 95 0 96 VII Conclusions In summary the results of this report explain
13. range vehicles are slightly higher than the lighter ones The reason for this is that the lighter vehicles have smaller engines than heavier ones and the bigger engine has the higher CO emission 10 7 0 1T 4T I 4T 6T 60 H o 50 I Q E40 I 59599 E Q 230 VES Q gt 999 99999 9 9 2 0 5999999 99 10 F I 0 0 1 6 11 16 21 26 3l 36 Figure 9 Vehicles Distribution According to Weight 9 00 8 00 7 0 en 4 6 Ton 7 00 6 6 6 00 N 3 sool 47 o 5 3 8 4 00 3 4 3 4 3 00 2 0 2 00 1 5 14 1 5 0 00 CO C02 100 NOx THC PM 10 Figure 10 FTP Normalized Emissions Averaged Over Vehicle Weight Emissions according to mileage In Figure 11 the distribution according to mileage is shown The range of mileage is going between 0 to 300 000 kilometers The distribution shows 25 64 of the vehicles in the low range 0 to 80 000 kilometers 6 15 in the middle range 80 000 to 160 000 kilometers and 8 21 in the high range 160 000 and more 11 The results in Figure 12 show the emissions by mileage distribution of the trucks There is some relationship between mileage and emissions NOx emissions seem to almost the same in the middle and high range and it is higher in the low range than the others CO and HC emissions are higher as the mileage increases CO emissions
14. show lower emissions on the middle range of mileage and higher in the high and low range of mileage PM emissions show higher emissions on the middle range of mileage and lower in the low range of mileage Again vehicle size is not equal throughout the size range complicating the picture and illustrating the need for a broad range of vehicle testing 300000 X 80 000 l 80 000 lt x lt x gt 160 000 160 000 gt 25000 I I I I Q N 9 20000 L I 1 Igo 8 150000 s 1 1 100000 I ba I gt ei 50000 5 5 9 9 Ly 1 6 11 16 21 26 31 36 Figure 11 Vehicles Distribution According to Mileage 12 Emission g km 8 00 7 00 6 00 5 00 4 00 3 00 2 00 0 00 7 18 E x lt 80 000 6 78 80000 lt lt 160000 625 628 625 628 x gt 160 000 552 3 60 3 53 3 53 3 35 2 81 2 47 141 154 co CO2 100 NOx THC PM 10 Figure 12 FTP Normalized Emissions Averaged Over Vehicle Mileage 13 Vehicle Emissions Under Different Driving Conditions Another purpose of this study is to determine how emissions vary under different driving conditions These conditions can be represented by the IVE driving bin designations The IVE model divides the range of driving situations into 20 vehicle en
15. the group to carry out the testing The local partner must also arrange for a zero gas and a calibration gas that is guaranteed to be within a 2 tolerance of specified values The testing program is begun at 06 30 when all personnel must arrive at the testing location and typically continues until 18 00 although on good days the testing may finish by 17 00 and on bad days the testing may take until 19 00 The daily work crew must be prepared to stay until testing is completed IX Analysis of Emissions Data Once collected the data needs to be divided into the appropriate 60 driving bins required by the IVE model based on the GPS data collected along with the emissions data The GPS evaluation program contains the necessary algorithms to estimate average emissions in each power bin to look at the relative emissions in the various power bins The binned GPS data can also be entered into the IVE model and emissions predicted for that driving pattern and vehicle technology These two comparisons will then indicate how well the IVE model is performing when averaged over the vehicles tested Based on the results emission adjustment files can be generated for the IVE model for the location of interest A Viewing GPS and Emissions Output The SEMTECH system outputs mass emissions second by second into a spreadsheet that can be opened in excel There is a template made called Raw Emissions Data xls that can be opened and the data post processed
16. the relationship between the real emissions and the estimated emissions as determined by the IVE model However this information is not complete without comparing the emissions of the light duty fleet in Xi an with others fleets around the world The comparisons in this chapter include six cities Beijing China Istanbul Turkey Mexico City Mexico Santiago Chile Sao Paulo Brazil and Xi an China In order to normalize the results and make them comparable the Bin methodology has been used to evaluate the emissions of each city under the FTP LA4 cycle The comparison includes the overall emissions for each campaign in each city It has to be noticed that in the case of Santiago the Light Duty vehicles are small diesel vehicle with less than 2 5 liter engines The Table 7 below displays the results Table 7 Emissions results for an average fleet in several cities Mexico Santiago Santiago Pollutant Xi an Beijing Istanbul Light Heavy Sao Paulo City Duty Duty CO g km 4 55 2 47 1 35 6 52 0 40 1 41 2 59 HC g km 1 54 1 06 0 51 0 78 0 04 0 48 0 55 NOx g km 6 85 5 67 3 58 5 91 1 10 3 13 5 30 PM 10 g km 1 92 2 37 0 92 3 81 0 09 0 42 1 48 CO 100 g km 3 50 4 82 3 36 5 40 2 21 2 85 4 84 In Figure 19 the results are shown with the 90 confidence interval so that one can better understand the variation in the measured data for each city and likely representativeness of the data for
17. to create the proper emissions files from the SEMTECH unit Also in this worksheet there are some graphs to view the emissions data in some common formats B Binning GPS and Emissions Output After processing the data in excel the file should be saved as a text file and used in the GPSEvaluate program This program will take all of the data files and compile them to create the emissions correction for each of the 60 bins as well as the driving fraction for each of the 60 bins The output file will be a text file that can be used in the IVE model The text files that are to be processed should be placed in the Data folder in the same folder with the GPSEvaluate program The program should then be started Figure VI 1 The program will list all files found in the Data folder at the time of program start These appear in the upper left hand window Clicking in the box to the left of the file names will cause the checked file to be evaluated when the Calculate button is 29 clicked For each group all data associated with that group is usually selected for the calculation EVALUATE GPS DATA Fije Edit N Select Files to Evaluate D AI f Speed Column 9 Min Time Jump sec 1 0 O flash gps data sample 155554 loq O flash gps data sarnbple2 155570 loq Altitude Column 7 Start Rows to Skip 3 d v Lists the files found in the data CO Column 11 v C02 Column 12 v v folder that might
18. would exist if the tested vehicles were randomly selected from the Xi an fleet The vehicles tested should be somewhat representative of the Xi an fleet thus the measured values are likely within 20 25 of the true mean of the Xi an fleet It should be noted that any zero emissions shown in Tables 3 or 4 indicates that emissions measured for the vehicles were below the detection limits of the equipment This only occurs in the case of CO and THC due to the fact that diesel vehicles run with high amounts of air compared to the fuel and a well running engine can have low CO and THC Table3 Emission Measurement Results for the Tested Xi an Diesel Fleet Measured Emissions FTP Normalized Emissions Test Vehicle Type Year Std grams kilometer grams kilometer Number CO NOx PM co THC CO NOx PM CO THC 1 Light Truck 2005 Euro2 341 5 62 0 325 10 93 1 93 401 7 74 0 392 13 25 2 16 2 Light Truck 2007 Euro2 283 3 42 0 071 1 60 1 19 336 4 70 0 088 1 97 1 38 3 Light Truck 2003 Euro 1 253 2 83 0 245 3 26 1 59 294 3 87 0 294 3 92 1 77 4 Light Truck 2007 Euro2 430 10 83 0 066 1 96 1 98 396 13 56 0 063 1 86 1 56 5 Light Truck 2001 Euro 1 284 3 23 0 359 3 63 1 48 350 4 64 0 458 4 64 1 79 6 Light Truck 2008 Euro2 275 4 25 0 148 5 63 1 38 328 5 50 0 179 6 88 1 64 7 Light Truck 2007 Euro 2
19. 0 Thus a second vehicle will be due at 10 15 On the first day only two tests should be scheduled to allow for proper on site training It is critical that vehicles not arrive late It is best to schedule them to arrive a little early The new vehicles will be parked in the test area leaving room for the returning vehicle to be parked Once the vehicle being tested arrives at the test setup facility the equipment is moved from the tested vehicle and installed in the new vehicle that has arrived for testing Buses are expected to arrive with only a driver Sand bags will be loaded onto the bus to simulate passenger weight Trucks should arrive with a half to a full load for purposes of 24 testing The truck or bus will be at the facility for about 3 hours for equipment installation testing and equipment removal It can then be returned to its owner Exhaust V Vehicle Driving Procedure Table IV 1 indicates the approach that will be used to test the vehicle The driving roads selected for the study should provide for convenient stopping locations that will occur at the desired time intervals and return the vehicle to the starting point at the desired time The roads selected should also allow for as great a variety of driving as feasible for the location It is critical that vehicles arrive on time A testing facilitator should be in touch with the vehicle suppliers to insure that the vehicles will arrive on schedule Table IV 1 Vehi
20. 11 FIGURE 10 FTP NORMALIZED EMISSIONS AVERAGED OVER VEHICLE WEIGHT ccceeeeer eene nennen 11 FIGURE 11 VEHICLES DISTRIBUTION ACCORDING TO MILEAGE cccssccccccsesssceceecessseeeccceessseeeecesssseeeceeesssseeceesensaeeees 12 FIGURE 12 FTP NORMALIZED EMISSIONS AVERAGED OVER VEHICLE MILEAGE ccccccessssessssssccscscccccceseseseseseeseeeens 13 FIGURE 13 FRACTION OF DRIVING IN VARIOUS BINS ccccccccssssseecceesssseeeceeeessseeccecessseeeccceessseeeeceesssseeecesessseeceesenaeeees 14 FIGURE 14 CO EMISSIONS FROM LIGHT DUTY VEHICLES BY IVE BIN eese nennen nennt nnne 14 FIGURE 15 NOX EMISSIONS BY IVE BIN ccs cccccssssssscseccesssceseccesssceccecesssenaccccessnsacescessssseesescenseaaeescessseaeeescesssaaeeccs 15 FIGURE 16 PM EMISSIONS BY IV E BIN 455 eicit Sere feeit tree eee Pa C cds co exh ous te regere 15 FIGURE 17 COMPARISON OF MEASURED EMISSION RATES WITH IVE PREDICTED EMISSION 17 FIGURE 18 COMPARISON OF MEASURED EMISSION IN SEVERAL CITIES NORMALIZED TO THE FTP LA4 CYCLE AND GROUPED TO SIMILAR SIZE DISTRIBUTIONS cccssssccccessssscecceceesseeecccesssseececessesseeeccesessseeeeeseessaeeeceeeesseeseesensaes 19 Introduction From April 4 to May 9 2008 a series of 40 diesel vehicles were tested in Xi an China All of these vehicles were classified as light heavy duty vehicles The tests were carried out in Xi an at a laboratory in Shaanxi Univ
21. 9994 1 6 11 16 21 26 31 36 1998 Figure 5 Number of Vehicles by Model Years for the Tested Light Duty Trucks g km 7 00 6 50 Wi 1999 2001 600 2002 2004 541 545 535 1 2005 2008 5 00 424 5 40 B g 8 321 8 3 12 a 2 93 0 B 300 2 74 m 217 1 91 200 137 134 1 32 1 00 0 00 co 02 100 NOx THC PM 10 Figure 6 Emissions Averaged over Selected Model Years for Light Duty g km Emissions according to Emissions Standard Figure 7 shows the distribution of the sampled vehicles All of the vehicles are of course Light Duty Trucks In addition one vehicle 3 complies the Euro 0 standard 11 vehicles 28 complies Euro 1 standard 27 69 complies Euro 2 1 3 a Euro Eurol Euro2 11 28 27 69 Light Trucks Figure 7 Vehicles Distribution According to Emissions Standard Figure 8 shows the emissions results for CO HC NOx PM and distributed by the vehicle engine standards The Overall results show a reasonable correlation with the standard looking from Euro through Euro 2 standards indicating a reduction for CO THC and PM10 The Euro 0 vehicle shows high levels of emissions for CO THC and PM but it shows lower levels of emissions for CO and NOx It appears that the Euro 0 vehicle s engine size is smaller than the others Observing results there is
22. A Study of the Emissions from Diesel Vehicles Operating in Xi an China June 2008 a 55 gt L Sebastian Tolvett ISSRC Huan Liu Tsinghua University Yingzhi Zhang Tsinghua University James Lents ISSRC Mauricio Osses University of Chile Kebin He Tsinghua University Table of Contents F TINTDIRODUG TION 3 552 R 1 TESTING eE E e E rE a 2 HE MEASUREMENT ERROR Toe Loop Re a eene PPP 5 IEEE OOADCEYELERHEONIUI PLU 6 V VEHICLE EMISSIONS UNDER DIFFERENT DRIVING CONDITIONS eene eee eene 14 VI EMISSION COMPARISONS WITH THE IVE MODEL 22222220222000080000000000000000000000000000000200 000000 16 CONCDEUSIONS i deese xies eetesteecVesseuseenetvesegeeeeed reso etie eee Sob eene eV eo ene dee Dese edo ev R rade entes Peso sea ese 18 List of Tables TABLE 1 DIESEL VEHICLES TESTED DURING THE STUDY ccssccsccsssssscecceeesssseeecccessseeceecessseeeceesessseeeeceesssseeecesensaeeees 1 TABLE 2 ESTIMATION OF EXPECTED VARIATION IN TEST DATA FOR REPEATED DRIVING 5 TABLE 3 EMISSION MEASUREMENT RESULTS FOR THE TESTED XT AN DIESEL FLEET eee 6 TABLE 4 EMISSION MEASUREMENT RESULTS FOR THE TESTED XI AN DIESEL FLEET CONTINUED
23. SRC data collected in similar gasoline emissions studies the collection A vehicle will typically not operate in all of the defined Power Bins during a given driving test Since this data is only used to calculate emissions projected for an FTP cycle it is only important to have values for the bins that occur in the FTP cycle This usually occurs In the few cases were a FTP bin is missing then the data is interpolated to fill in values of data from a fleet of randomly selected gasoline fueled vehicles resulted in 9096 confidence interval of plus or minus 20 When all potential errors are combined it should be anticipated that this study will produce results which are to a 90 probability to within 20 30 of the actual emissions produced by the local fleet While this potential error is larger than preferred it is still better than using emission estimates derived from studies in the U S and Europe In the long run more emissions tests are required in order to reduce the mobile source inventory uncertainty to the more preferred 1096 range IV Overall Results Table 3 and Table 4 present the average emissions measured for the various vehicles tested in the program They are listed in the order tested An average value and 90 confidence limits are also included at the end of Table 4 The 90 confidence interval in Table 4 indicates the range of emissions for which there is a 9096 probability that the true mean emission rate of the fleet
24. Truck JINBEI Euro 2 2008 5765 4295 27 Light Truck JIANGHUAI Euro 2 2007 40077 3295 28 Light Truck SHIHUA Euro 2 2005 62524 2360 29 Light Truck FUTIAN Euro 1 2003 167155 4000 30 Light Truck SHIDAI Euro 2 2007 18833 2690 31 Light Truck YUEJIN Euro 2 2005 115075 2170 32 Light Truck YUEJIN Euro 2 2008 1623 2080 33 Light Truck YUEJIN Euro 1 2004 91743 3815 34 Light Truck JIANGHUAI Euro 1 2001 211500 5750 35 Light Truck JIANGHUAI Euro 2 2006 43968 3295 36 Light Truck DONGFENG Euro 2 2006 53887 4200 37 Light Truck DONGFENG Euro 2 2004 73125 4420 38 Light Truck DONGFENG Euro 1 2002 206809 4170 39 Light Truck YUEJIN Euro 2 2007 24525 2895 40 Light Truck Euro 1 2003 87397 4661 II This study was a joint effort of the Tsinghua University and the International Sustainable Systems Research Center ISSRC Testing Procedure Vehicles were brought to the test site by drivers supplied by the owners of the vehicles for test equipment installation These vehicles were warmed up at the time of the testing Once the emissions testing equipment was installed the vehicles were driven over a prescribed driving circuit by the original vehicle drivers The driving route was designed so that the vehicles would be operated over as wide a range of operating conditions as could be achieved within the city limits of Xi an The driving circuit required from 30 to 40 minutes to complete depending upon the traffic situation and included a moderate hill that the vehicl
25. ation II 1 becomes Lo M V n 1 11 2 where M measured sample mean In this special case to insure that the measured mean has a 70 probability of being within 15 of the actual mean requires a sample size of 44 vehicles The actual variation in emissions from similar technologies is unknown but based on the previous discussion it is clear that a relatively large number of vehicles of a given technology class should be tested For purposes of this study at least 10 vehicles of each important technology should be measured to insure even a moderate level of confidence in the results Once the data is collected the variance in the data of similar vehicles will establish the true confidence that can be placed in the results of the tests 23 ART With present vehicle testing technology about 1 5 hours are required to remove the equipment from one vehicle and install the sampling equipment in a second vehicle To collect data for of an hour for a given vehicle will thus require a total of 2 25 hours per vehicle In a 9 hour day about 4 vehicles can be sampled In a two week sampling period 10 sampling days about 40 vehicles can be studied Thus based on the preceding discussion only four general vehicle technology groups should be studied over the two week sampling period in order to insure at least 10 vehicles per technology class are studied The variety of diesel engine technologies operating in most urban areas today are relativel
26. be processed N Column 13 VOC Column 14 alumn 3 No Limit On Idle CALCULATE M amt ii Time OffseHnis Calculation Results Low 1 Stress Med 21 222 eesti 24 ee 26s 27 a ee 32315533 5343 37 40 Stress 52 63 5B amp 55 56 57 58 59 60 46 47 48 49 50 51 Displays results including er een Average Spe 41 42 431 44 45 SCs percentage in each bin emissions in each bin overall number of data Indicates what information will be points processed and average displayed in lower portion of nnd ee speed program Options are Driving ropdown menus indicating the fractions CO CO2 PM VOC or columns for the time and speed data NOx The display does not impact the start rows to skip columns for each output files all data is always pollutant and other user options provided in the output files Figure VIII 1 GPSEvaluate Program The upper right portion of the program displays the current settings for the program A description of each setting is described in the Table VI 1 below 30 Table VIII 1 Description of the Options in the GPSEvaluate Program Parameter Default Units Description Value Time column 1 hh mm ss Indicates which column the hour min and second is in the GPS text files The GPS units report this information in the column 1 when counting from 0 see Table
27. cle Driving Procedure Step Procedure Time Interval 1 A vehicle arrives at the test setup facility at the designated appointment time while previous vehicle is being tested 2 Vehicle will be parked in the next vehicle test setup location 5 minutes Vehicle will be studied and a decision will be made as to the best 3 way to attach testing equipment to the just arrived vehicle Sand 20 minutes bags are loaded onto vehicle to be tested 4 Tested vehicle returns to the test setup location and parks near the 5 minutes 25 next vehicle setup location 5 Download data from the just tested vehicle 5 minutes 6 Test equipment is removed from tested vehicle and transferred to 30 minutes new vehicle and tested vehicle released for return to the owner 7 Equipment installed on new vehicle 25 minutes Data collection initiated and vehicle started and driven over the 8 45 minutes designated one hour test route 9 Total time to test one vehicle 135 minutes Traffic will of course impact the distances that will be covered during the driving phase Thus the test route should be designed so that there are alternate routes to be taken so that the vehicle can complete its test run in the 45 minutes that are allocated Since traffic will flow better at various times of the day the test may be completed in 30 minutes in one case and in 60 minutes in another case The test route should be sel
28. ected so that the vehicle can complete the test run in 60 minutes in the worst traffic It is also critical that the driving course selected contain street sections where higher speeds and accelerations can be achieved as well as slower speeds and lower accelerations The driver should operate the vehicle in a manner typical of the traffic that is occurring at the time of testing and in the manner that the vehicle is normally used i e a bus will stop at bus stops even though it does not pick up or discharge passengers Buses and trucks should be marked with signs taped to the vehicle indicating that the vehicle is participating in a testing program VI Vehicle Procurement Procuring 40 large diesel vehicles for testing with a driver and in the case of trucks can bea challenge Bus companies must be contacted as well as trucking companies to find the desired vehicles In both Mexico City and Sao Paulo a US50 per vehicle fee was paid for gasoline fueled vehicle This fee plus the use of contacts at the partnering agencies provided all of the needed vehicles in Sao Paulo In the case of buses and trucks a higher fee may be necessary unless representative buses can be obtained from government sources supportive of the testing program It is recommended that 200 300 be set aside for payment to bus truck owners for providing a vehicle and driver for the approximate 3 hour testing program However this is a local decision that should be made
29. ectronic Flow Meter Black Box For Diluter Semtech D Dekati DMM Figure 3 Exterior of a Truck Outfitted for Emissions Testing Water Barrel Figure 4 Water Barrels for Emissions Testing In order to simulate a loaded truck 200 Kilograms of water in barrels were placed on the truck according to the carrying capacity of the truck Depending upon the size of the vehicles barrels were loaded to simulate 50 of the total load capacity to produce consistent measurements Appendix A contains a description of the overall testing procedure and data processing steps III Measurement Error No measurement process is free from measurement and operating error Referring to Figure 2 there is the potential for measurement error in the flow measurement process the dilution rate measurement the gas concentrations measurement Table 2 outlines potential error assuming that each process can be held to produce only 2 error to help understand the expected variations in results from the repeated testing Table 2 Estimation of Expected Variation in Test Data for Repeated Driving Cycles Impact on Gaseous Impact on Particle Measurement Process Measurements Measurements Exhaust Volume Flow Measurement 296 296 Dilution Measurement 2 Emissions Concentration Measurement 2 2 Total Potential Variation 4 6 To further complicate the process data is collected on normal city streets which resu
30. el Fleet continued Measured Emissions FTP Normalized Emissions Vehicle Type Year Std grams kilometer grams kilometer CO NOx PM co THC CO NOx PM co THC Test Number 22 Light Truck 2008 Euro2 301 3 20 0 161 2 36 0 69 353 4 04 0 193 2 86 0 80 23 Light Truck 2008 Euro2 288 7 63 0 047 1 99 1 07 361 10 49 0 061 2 57 1 33 24 Light Truck 2002 Euro1 282 3 52 0 673 2 43 1 74 344 4 79 0 846 3 06 2 13 25 Light Truck 2002 Euro 1 351 3 55 0 180 6 75 2 11 346 4 18 0 182 6 83 1 93 26 Light Truck 2008 Euro2 336 5 63 0 173 2 15 1 45 425 7 81 0 216 2 70 1 79 27 Light Truck 2007 Euro2 444 4 60 0 156 4 01 1 68 482 5 52 0 174 448 1 79 28 Light Truck 2005 Euro2 353 9 00 0 076 1 95 1 19 419 12 28 0 093 2 37 1 37 29 Light Truck 2003 Euro 1 295 5 94 0 206 7 73 1 76 333 7 73 0 283 8 74 1 91 30 Light Truck 2007 Euro2 269 2 90 0 266 445 1 30 306 3 82 0 312 520 1 43 31 Light Truck 2005 Euro2 251 4 24 0 103 1 86 1 37 282 5 32 0 119 2 16 1 54 32 Light Truck 2008 Euro2 294 5 06 0 011 1 46 1 22 368 6 51 0 014 1 77 1 55 33 Light Truck 2004 Euro 1 237 5 52 0 001 3 26 1 26 305 7 55 0 001 4 24 1 67 34 Light Truck 2001 Euro 1 287 4 94 0 160 4 14 1 71 332 5 87 0 155 4 03 1 98 35 Light Truck 2006 Euro2 366 6 77 0 107 3 41 1 60 380 7 99
31. ergy demand situations and 3 engine stress situations Figures 13 14 15 and 16 present emissions from the diesel vehicles as a function of IVE driving bin 0 45 Driving Bir 0 4 F 0 35 0 3 f 0 25 f 0 2 F 0 157 e 0 05 f 0 1 00 1 03 1 06 1 09 1 12 1 15 1 18 2 01 2 04 2 07 2 10 2 13 2 16 2 19 3 02 3 05 3 08 3 11 3 14 3 17 Figure 13 Fraction of Driving in Various Bins 8r co2 7r e eL _ at EN tet x e Sal gt eti 1 e rt rec EE 1 00 1 03 1 06 1 09 1 12 1 15 1 18 2 01 2 04 2 07 2 10 2 13 2 16 2 19 3 02 3 05 3 08 3 11 3 14 3 17 Figure 14 CO Emissions From Light Duty Vehicles by IVE Bin The emissions look typical with the exception of the apparent fall off in emission rates in stress category in the case of bins 15 19 i e 1 15 to 1 19 in Figures 14 15 and 16 Reviewing Figure 13 there are many seconds of data in the bins 9 15 i e 1 09 to 1 15 in Figures 14 15 and 16 There is very little data in bins 15 19 This results in the classification of data into erroneously high bins It appears that momentary deviations in GPS altitude and speed produced erroneous calculations of road grade and acceleration It has been found that the GPS unit will loose signal freeze and then jump to the correct speed a few seconds to a minute later when the The energy demand on a vehicle is the result of engine and rolling fr
32. ersity of Science and Technology Table lindicates the vehicles that were tested Table 1 Diesel Vehicles Tested During the Study MUR Vehicle Type Model Emission Standard Year ne en 1 Light Truck JIEFANG Euro 2 2005 47485 2480 2 Light Truck JINBEI Euro 2 2007 24000 2480 3 Light Truck FUTIAN Euro 1 2003 129578 2430 4 Light Truck KAIMA Euro 2 2007 20282 2790 5 Light Truck LANLING Euro 1 2001 230000 3100 6 Light Truck JIANGHUAI Euro 2 2008 7617 2495 7 Light Truck JINBEI Euro 2 2007 45678 2360 8 Light Truck YUEJIN Euro 0 1999 264945 2450 9 Light Truck YUEJIN Euro 2 2005 107805 3470 10 Light Truck YUEJIN Euro 2 2007 8184 2680 12 Light Truck JINBEI Euro 2 2007 32863 2340 11 Light Truck YUEJIN Euro 2 2005 65731 2165 13 Light Truck YUEJIN Euro 2 2007 9776 3710 14 Light Truck JINBEI Euro 1 2002 163468 1950 15 Light Truck JIANGHUAI Euro 1 2001 234500 4000 16 Light Truck YUEJIN Euro 2 2007 18546 2680 17 Light Truck JINBEI Euro 2 2007 25725 2500 18 Light Truck JIEFANG Euro 2 2006 75000 3240 19 Light Truck YUEJIN Euro 2 2005 71951 2290 20 Light Truck SHI DAI Euro 2 2007 35000 2070 21 Light Truck JINBEI Euro 1 2002 156135 3890 22 Light Truck JINBEI Euro 2 2008 3654 2340 23 Light Truck JINBEI Euro 2 2008 4753 2810 24 Light Truck FUTIAN Euro 1 2002 116695 2200 25 Light Truck QINGQI Euro 1 2002 172691 2450 26 Light
33. es drove over For emission measurement purposes a Semtech Sensor D gas emissions testing unit was used to measure the emissions of CO total Hydrocarbons THC NOx and NO The Sensor D unit uses infrared absorption technology to measure CO and CO ultraviolet absorption technology to measure NOx and NO and a flame ionization detector to measure total hydrocarbon emissions The Sensor D testing unit is an integrated emissions testing device designed to be used in on road testing programs The Sensor D measures emission concentrations and must be provided with exhaust flow rates and ambient temperatures and pressures in order to determine mass emission rates The Sensor D is equipped with a temperature pressure sensor A Semtech manufactured 4 inch 10 cm exhaust flow measurement device was used to measure the exhaust flow rate from the vehicles This device uses standard dynamic and static pressure measurement techniques to calculate exhaust flow The Sensor D was also equipped with a GPS device to measure location and speed AII data were collected at one second intervals For further information on the Sensor D test unit and the Semtech exhaust flow device please go to www sensors inc com The Sensor D test unit was zeroed and spanned at each set of test cycles The unit was found to be very stable from day to day with the zero and span holding within 196 of the calibration gases values from day to day Particulates were measured
34. essary adjustment to the NO and NO results from the NDUV based upon the humidity of the intake air Data also collected on a 1 hertz cycle from an onboard GPS unit allows the measured mass of each pollutant to be matched up with the driving activities of the vehicle The PEM including protruding knobs and connectors measures 404 mm in height by 516 mm in width by 622 mm in depth It weighs approximately 35 kg The ID of the mass flow measurement device will have a diameter of 10 2cm Except during actual testing the internal temperatures of the PEM will be maintained using a line serviced 12 volt DC power supply A Y connector allows the PEM to be simultaneously connected to the line serviced power supply as well as a deep cycle 12 volt battery Prior to starting the first test each day the PEM will undergo a leak test as 27 well as a zero span and if necessary calibration test The proper size mass flow measurement device will be selected based upon the engine size of the test vehicle This will insure that a backpressure of less than ten inches of water column is maintained during the testing The mass flow measurement device will then be attached to the rear of the vehicle using high vacuum suction cups A high temperature silicone sleeve sized to match the OD of the tailpipe will be attached to the tailpipe with a hose clamp The silicone sleeve will be attached to flexible silicone transport tubing A second silicone sleeve wi
35. hat diesel emissions be well understood and that air quality planners be able to predict the impact of diesels in the present time and at times in the future based on specific control scenarios To support these efforts a process of on road measurement of diesel emissions has been devised and the International Vehicle Emissions IVE model was developed to estimate emissions from diesel vehicles under different driving and control scenarios The IVE model is designed to make estimates of in use vehicle emissions in the full range of global urban areas At the point in time of IVE model development data to establish base emission factors and driving pattern adjustments were of necessity based on vehicle studies carried out primarily in the United States This has raised questions as to the applicability of the base emission rates and driving pattern adjustments used in the model to developing countries The IVE in use vehicle emissions study is designed to test the hypothesis that similar vehicle technologies will produce equivalent emission results in a given location and to provide some rudimentary data for creating improved emission factors The IVE modeling framework provides the user with the ability to enter adjustments to the base emission factors that are specific to a location in case the supplied factors are found to be in error This capability was built into the model to support emission measurement studies that would be made in developing
36. he IVE model These emission factors will apply a correction to the IVE emission rates already used in the model To calculate the change in emissions from the IVE default emissions to the new measured emissions emissions will need to be predicted on the same driving trace as the emissions measurements were made on This means a driving trace for the overall driving conducted during the emission measurement test procedure will need to be created and input into the IVE model The GPSEvaluate Program has already made a composite set of data with fractions of driving in each bin that add up to 100 This data can be entered into the IVE model in one of two ways The data can simply be entered into the IVE model directly into the location page Figure VI 2 While this is a simple option for entering in data for a single file this can be time consuming for many data files or many hours of the day For multiple files the import function in the Location File Template may be used Figure VI 3 To use the Location File Template follow the instructions on the first spreadsheet in the workbook or refer to the GPS Operating Instructions document 32 2 EVALUATE GPS DATA File Edit Select Files to Evaluate dmsboums O Al Speed Column 9 vB Min Time Jump sec 1 0 v 4 BusDataExample txt flash gps data 040826 233826 lo Altitude Column 7 v gj Start Rows to Skip 3 v O flash gps data 1 155554 log
37. hicles Average Velocity for Group 2 Vehicles Driving Style Distribution Facility Cycle Distribution Group 2 Vehicles 1 VSP Bin 1 VSP Bin 2 VSP Bin 3 VSP Bin4 VSPBin5 VSP Bin 6 VSP Bin 7 Sec seconds min minutes hr hours Mhr 1000 s of hours 1 km kilometers Mkm 10005 of kilometers mi miles Mmi thousands of miles Soak Time Distribution Group 2 Vehicles IS single units M 1000 s 1 IC degrees Centigrade F degrees Fahrenheit m s meters second mph miles per hour km hr kilometers hour 1 Description Driving Style Distribution Facility Cycle Distribution Group 1 Vehicles Time Period VSP Bin 1 VSP Bin2 VSP Bin3 VSP Bin4 VSP Bin 5 VSP Bin6 VSP Bin 7 Total Distance or Time Driven Number of Statups Soak Time Distribution Group 1 Vehicles Temperature Relative Humidity Average Velocity for Group 1 Average Velocity for Group 2 Vehicles 1 hour 2 hour 3 hours 4 hours 6 hours 1 hour 2 hour 3 hours 4 hours 6 hours Driving Style Distribution Facility Cycle Distribution Group 2 Vehicles VSP Bin 1 VSP Bin2 VSP Bin3 VSP Bin4 _VSPBin5 VSP Bin6 VSP Bin 7 1 sec seconds min minutes hr hours Mhr 1000 s of hours jkm kilometers Mkm 1000s of kilometers mi miles Mmi thousands of miles I Soak Time Distribution Group 2 Vehicles IS single units M 1000 s 1 IC degrees Centigrade F degrees Fahrenheit m s meters second mph miles per hour km hr kilometers hour Figure VIIL3 Location File Templa
38. iction wind resistance acceleration energy and road grade For a further discussion the reader is referred to the user s manual for the IVE model which can be obtained at www issrc org ive Engine stress relates to engine rpm and the average energy demand on the vehicle in the most recent 15 seconds The reader is referred to the user s manual for the IVE model which can be obtained at www issrc org ive 14 signal returns Altitude can also be mis measured by the GPS Steps are taken to filter these events out of the data however a few data points slip by The data in bins 1 15 1 19 in Figure 6 represent only 0 001 of the collected data and are included only for the sake of completeness We believe that these data should be ignored In the case of bins 1 5 i e 1 01 to 1 05 in Figure 6 the points are higher than normal Due to the emergency braking it is likely that driving occurred in bins 1 01 to 1 05 In the course that we drove in Xi an there are a few speed bumps on the road and the vehicles that we tested were rapidly slowed down when they met the speed bumps to avoid damage to the testing equipment Figure 15 presents data from the same vehicles but this data is the NOx data from those vehicles 0 14 NOx 0 12 _ 0 1 KON E 0 08 id 5 2 0 06 e 0 04 Me F wo Feet 7 1 00 1 03 1 06 1 09 1 12 1 15 1 18 2 01 2 04 2 07 2 10 2 13 2 16 2 19 3 02 3 05
39. ited data does not provide large enough samples of individual technologies to do an analysis of emission comparisons by technology type Instead the IVE model was run using an FTP driving pattern the pattern used to develop base emission factors for the IVE model and using the overall distribution of vehicles tested in Xi an The average measured values normalized to FTP driving cycles were then divided by the IVE predicted values to evaluate the comparisons Figure 17 provides the results of this analysis As can be seen the CO emission projections were accurate producing a ratio close to 1 The other predictions however showed a wide variance The model appears to be underestimating the emissions for all the vehicles except NOx and PM for Euro 0 and PM for Euro 1 but actually they are almost the same between model prediction and measured value in NOx and PM for Euro 0 For Euro 1 and Euro 2 the model is overestimating the emissions for CO HC and NOx The exact value for all the vehicles is 1 29 16 12 00 1000 I 8 00 L amp 600 T El E2 x ib BOA 4 00 L 200 7 rm G H E a 0 00 CO Ratio HC Ratio NOx Ratio PM Ratio CO2 Ratio Figure 17 Comparison of Measured Emission Rates with IVE Predicted Emission Rates The default base emission factors in the model are based
40. ll be used to attach the other end of the transport tubing to the mass flow measurement device The PEM will be disconnected from the line serviced 12 volt power supply and placed in the trunk or back seat of the test vehicle along with the deep cycle 12 volt battery A 18 foot sample line will be used to connect the mass flow measurement device to the sample input system of the PEM The GPS unit will be magnetically attached to the roof of the vehicle and connected to the PEM The temperature and humidity probe will be located near the front of the vehicle and connected to the PEM If the PEM is placed in the trunk a special piece of hardware will be used to allow the lid of the trunk to be latched but still allow space for the sample line and other lines to be connected to the external devices At this point the PEM will be switched to the measurement mode and the engine of the test vehicle will be started Following completion of the vehicle driving procedure described earlier in Table IV 1 the installation process will be reversed to remove the PEM from the vehicle The data collected will be downloaded to a laptop computer at the end of each vehicle test At the end of each day a span check will be conducted to observe the sustained linearity of the system Calibration gases are a critical component of insuring that the measurements by the Semtech D are correct The following table recommends gas concentrations for calibrating and auditing the Se
41. lts in different driving patterns from test to test Daily variations in traffic flow have a major impact on how the vehicles can be operated Thus emissions can vary considerably from test to test even using the same vehicle To correct for this variation the data is divided into different power demand categories 60 power demand categories are used for this purpose These categories are typically referred to as Power Bins and are numbered from 0 to 59 The amount of emissions that occurs when the vehicle is operated in each of the 60 Power Bins is determined This bin emission rate is multiplied by the driving distribution that would have occurred had the vehicle driven an FTP driving cycle to produce a standardized estimate of emissions that would have resulted if the vehicle had been operated on an FTP cycle This approach was found in an already published study in Brazil to produce estimates of emissions on the actual driving cycle within 6 While this is good in many respects it must be added to measurement uncertainty indicated in Table 2 which results in a potential emissions error of 10 12 overall The error discussed in the previous paragraphs should be random and thus should average out to some degree over multiple tests Finally the number of vehicles that can be tested in a 2 week period is limited This limited testing further decreases the certainty of how well the tested fleet actually represents the actual urban fleet Based on IS
42. lumn or if calculations for each hour should be performed End hour 23 n a Indicates which hour of the day to end the data processing according to the time in the time column This does not apply if hourly calculation has been selected in the start hour column CO column n a Mass sec Indicates which column the CO emissions are in if they exist CO2 column n a Mass sec Indicates which column the CO2 emissions are in if they exist NOx column n a Mass sec Indicates which column the NOx emissions are in if they exist VOC column n a Mass sec Indicates which column the VOC emissions are in if they exist PM column n a Mass sec Indicates which column the PM emissions are in if they exist No Limit on No minutes Indicates the maximum time to allow for idling in the program If Idle Limit this is set to 10 minutes the program would set any idle time defined as a velocity of less than 5m s of longer than 10 minutes to 10 minutes Satellite n a Integer Indicates the column that contains the number of satellites This column through column is optional and is not used in the default configuration If this 14 option is selected program will ignore data that has less than 3 satellites Straight Speed Straight n a Indicates whether to average the current row of data and the previous row average speed or to use each data point separately straight speed Save Settings n a n a This button will save the current settings Set
43. mtech D unit The audit gases may be skipped if it 1s difficult to get gases or if the cost is beyond that budgeted for the project Gas For Unit Calibration For Unit Auditing CO2 12 6 CO 1200 ppmv 200 ppmv NO 1500 ppmv 300 ppmv Total Hydrocarbons as Propane 200 ppmv 50 ppmv VIII Local Support Requirements The most difficult job for the local partnering agencies is the procurement of the needed 40 vehicles This procedure needs to be started one month or more before the beginning of testing Each vehicle owner is required to bring their vehicle for testing at least exactly at the scheduled time In addition a secure location must be found where two large vehicles can be parked and sampling equipment removed from one and installed on another 28 Once the testing is begun a person is needed to insure that the next vehicle will arrive on time and to help with installation of equipment and data downloading An experienced driver is needed to drive the vehicle This should be supplied by the vehicle owner An experienced mechanic is needed to help install the test equipment and to identify the engine type and technology Necessary ladders to enable the installers to reach the exhaust for connection will be required In the case of buses sand bags representing a the weight of a 2 3 full bus must be available along with two persons to load the bags onto the bus The ISSRC team will supply one person to work with
44. ng device to measure particulate emissions is also used during the study to establish real time particulate emissions from the tested diesel vehicles The IVE in use vehicle emissions study is built around a two week study period where on road vehicle emissions data is collected Equipment Needed to Complete Study A wide range of equipment is required to carry out the diesel emissions study The key pieces of equipment will be shipped from the United States However a significant amount of equipment and supplies must be provided locally An Excel spreadsheet program is provided with this write up that indicates the equipment that will be sent from the United States and the equipment that must be procured locally III Sample Size and Impact on Emissions Measurement Reliability Unfortunately for the researcher studying the emissions from on road vehicles the variance in emissions among vehicles with similar technologies is quite large This means that multiple tests on different vehicles are required to accurately establish the true fleet wide average for a given technology Equation II 1 indicates the 70 confidence interval for data in a Gaussian distribution 170 0 V 1 1 where Lo 70 confidence interval o standard deviation n sample size In the case of vehicular emissions o is often close to the sample mean although diesel vehicles show a little less variation that do gasoline fueled vehicles In this case Equ
45. on a second by second basis using a Dekati DMM testing unit This unit uses a particle charging process and six stage impactor setup to determine particle mass The DMM measures particle concentration The exhaust flow rates collected by the Sensor D unit must be used with the Dekati measurements to determine particulate mass flow rates The DMM measures particles in the 0 to 1 5 micron range which is the size range where virtually all diesel particulates reside The DMM has been found to produce results comparable to the reference particulate sampling methods for diesel particulates although it was found to produce readings about 30 high in one published study Dekati experts believe that this is due to the fact that the Dekati measurement process can measure volatile particulate matter that is lost in the case of filter based particulate sampling devices For further information on the DMM please see www dekati com The DMM was zeroed at the beginning of each testing cycle The charging and impactor units become covered with particulates and must be cleaned after each 2 3 hours of testing to keep the unit operating properly The DMM can not handle the mass concentrations found in uncontrolled diesel exhaust Thus the diesel exhaust must be diluted at a controlled rate in order to use the DMM A field dilution device was developed by ISSRC to use in on road emissions testing with the DMM Figure 1 illustrates the design of the ISSRC field dilution
46. t Figure VI 4 Any time this base correction factor file is used it will correct the emissions predicted by a factor of 1 3 for CO for this specific technology 34 Base Adjustments Base Adjustment file Example x Add Technology all FUEL TYPES all AIRIFUEL v __ 8 un 418 Pt Auto SmTk Lt MPF 3Wy PCV 80 161K km Y 2 8 vos wx sos mm 118 Pt Auto SmTk Lt MPFI 3Wy PCV 80 161K km cg sapo in Figure VIILA Applying Location Emission Correction Factors in the IVE model 35
47. te in Excel 15 min 30 min 1 hour 2 hour 3 hours 4 hours Once the driving fractions have been entered select all other information as close as possible to match the emissions testing conditions in the Location Page This includes selecting the ambient temperature and humidity fuel specifications and fleet The user will have to create a fleet file to represent the type of vehicle tested in this study For deriving correction factors only one technology should be used at a time To more information on how to fill out the location file and creating a fleet file please refer to the IVE user s manual Once the fleet and location file have been properly filled out the user can run the model and record the emission rate per distance for each pollutant Once the emissions values have been predicted by the IVE model these values can then be compared with the actual emissions values that were collected in the study To derive the correction factors simply divide the measured emission value over the predicted value to get the correction factor for that specific technology Then in the IVE model this correction should be entered and used when predicting emissions from this area For example if the IVE model predicts a CO emission rate of 10 g mi and the emissions measurements indicated on average an emission rate of 13 g mi of CO the correction factor for this technology would be 1 3 This information is entered in the base correction factor workshee
48. tings should be saved in Button the Settings Folder as a txt file Load Settings n a n a This button will load the file named GPSEvaluateSettings txt that Button is located in the Settings Folder Time Offset 0 0 hours This is to enter the time difference from UTC GMT time reported Button in the GPS data to local time If location is 6 hours from GMT enter 6 If location is 6 hours from GMT enter 18 3l Once the appropriate settings have been selected or loaded and the files to process have been checked in the boxes the user is ready to process the data by pressing Calculate The bar above the Calculate button will show you the status of the calculation The calculation may take a few minutes especially with many data files or long data files Once the calculation has been finished the results will be displayed in the bottom half of the program There will be the percentage of travel in each of the 60 bins along with the total number of rows processed and the average speed over all the files It is also possible to save the output of the file analysis Click on the Save Output button and a text file with the information contained in the Results box can be saved All data on the driving and emissions will be saved in a text file C Applying Base Correction Factors in the IVE model You can use the emissions data collected in the field study to derive base or emission correction factors in t
49. unit Pressure Tap for Flow Measurement cA From Exhaust PP Micro Filter 99 9 PM2 5 removal Diluted Exhaust to Dekati Sampler 10 liters minute Dilution Control Figure 1 ISSRC Field Dilution Device The exhaust flow in the dilution device is measured using a Dwyer differential pressure transducer which is accurate to 0 25 of full scale The differential pressure gauge is used to measure the pressure difference between P2 and P3 shown in Figure 1 A micro filter produces particle free air to be diluted with the exhaust sample The exhaust sample and dilution air are heated to 110 degrees C to avoid water and organic condensation The dilution level reaches values from 20 to 1 to 30 to 1 depending on the vehicle tested and the exhaust flow rate Figure 2 presents a flow diagram for the overall emissions testing system The data collected by Vehicle Exhaust peated Sample Line Sensor D Gas Measurement Flow Measurement Device Device mple i Line Dekati Partical Measurement Device Figure 2 Flow Diagram for the Overall Emissions Testing System the flow measurement device and the Sensor D are recorded to a flash card on the Sensor D unit The Dekati information is recorded to a laptop computer that is connected to the Dekati by a serial cable Figure 3 and Figure 4 show the exterior of a truck outfitted for testing Flow Meter Diluter d ar Exhaust Hose El
50. with use This is an unusual result but may be because the fleet tested in Xi an was relatively homogeneous The fact that emissions from the Xi an diesel vehicles seem to run higher than comparable veh icles in the other cities tested may suggest that maintenance in Xi an may be lax It might be good to establish a traditional Inspection and Maintenance program for vehicles or to use remote 19 sensing to measure the emission rates of trucks as they transverse the city to identify and repair high emitters In addition some differences of emissions were found among vehicles supposedly conforming to different vehicle emission standards which mean there is effective emission improvement for diesel trucks in Xi an during in recent years with tightening emission standards Particulate and NOx control devices are becoming available for reducing diesel emissions Xi an may want to take advantage of these controls by setting more stringent new vehicle standards and by considering some form of retrofit program for diesel vehicles 20 Appendix A Field Manual For Diesel Vehicle Testing 2 IVE In Use Vehicle Emissions Study for Diesel Vehicles I Introduction Diesel emissions are important contributors to air quality degradation in urban areas Diesel particulates are considered to be carcinogenic or likely carcinogens in the United States and diesels are often the prime source of nitrogen oxide emissions It is thus important t
51. y small and the study of the four most predominate vehicle technologies in an area will provide useful data for understanding the overall diesel emissions in an urban area IV Sampling Program Based on Section II it is desired to study four vehicle technology classes during the two week study The vehicle technology classes that should be studied are those groups which dominate the local diesel fleet being studied and which will continue to be important in the next 5 years The vehicles selected may vary from location to location but based on previous experience it is suggested that the following four technology classes be considered Euro 1 type technologies Euro 2 type technologies Euro 3 type technologies Euro 4 type technologies if available or extend testing of most common of the three previous groups The previous suggested technology classes should not be rigidly adhered to in cases where the local fleet does not contain significant numbers of vehicles in any of the vehicle classes listed It is best to tailor the study to the makeup of the local fleet For this paper the four suggested classes will be used for discussion purposes Start emissions are important for gasoline vehicles but are not considered as important for diesel vehicles Thus the testing program that will be used will not collect diesel vehicle start emissions Vehicles will be scheduled to be brought to the testing area at 2 25 hour intervals beginning at 08 0
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