Evaluation of the suitability to European conditions of the WNTE control zone concept as set out in the OCE GTR

Transcription

1 Evaluation of the suitability to European conditions of the WNTE control zone concept as set out in the OCE GTR Henk Dekker - TNO Stefan Hausberger, Martin Rexeis - TUG Patrik Soltic EMPA Heinz Steven - TUEV Nord 10 October 2006

2 WNTE Evaluation European driving conditions European ambient conditions Evaluation WNTE control zone and alternative approaches 10/10/2006 WNTE Evaluation 2

3 WNTE Ambient Conditions Proposal Measurements valid if altitude < 1680 m above sea level humidity between 7.14 and g water per kg dry air. Outside these conditions: correction factors for the emissions. ambient temperature between 12 and approximately 35 C (two options exist). Below 12 C : correction factors, above about 35 C correction factors (option A) or invalidity (option B) 10/10/2006 WNTE Evaluation 3

4 Analysis of Ambient Conditions in Europe Main alp-crossing transitions Brenner (1375 m), Frejus (1312 m) and Gotthard (1175 m ) lie below the proposed 1680 m Weather: Analysis of daily European weather stations data of the year 2005 (source: NOAA) latitude [ ] altitude [m.a.s.l.] number of stations longitude [ ] station altitude [m.a.s.l.] Average daily temperature of all stations: 9.6 C 10/10/2006 WNTE Evaluation 4

5 Frequency Distribution of Temperature and Humidity hot&dry zone (total 0%) hot zone (total 0%) hot&wet zone (total 0%) average temperature [ C] dry zone (total 2.5%) cold&dry zone (total 47.2%) WNTE zone (total 20.4%) cold zone (total 11.4%) wet zone (total 18.5%) cold&wet zone (total 0%) Frequency (%) humidity [g/kg] Only 20.4% of average temperatures in 2005 lied within the proposed WNTE conditions 10/10/2006 WNTE Evaluation 5

6 Geographical Distribution of the Weather Conditions latitude [ ] hot&dry: T > 35 C & humidity < 7.14 g/kg 70 total : % hot: T > 35 C & humidity g/kg total : % Frequency (%) latitude [ ] Frequency (%) latitude [ ] hot&wet: T > 35 C & humidity > g/kg 70 total :0.0016% Frequency (%) longitude [ ] longitude [ ] longitude [ ] 0 dry: T C & humidity < 7.14 g/kg 70 total :2.56% in WNTE ambient boundaries total :20.4% 100 wet: T C & humidity > g/kg 70 total :18.5% latitude [ ] Frequency (%) latitude [ ] Frequency (%) latitude [ ] Frequency (%) longitude [ ] longitude [ ] longitude [ ] 0 cold&dry: T < 12 C & humidity < 7.14 g/kg 70 total :47.2% 100 cold: T < 12 C & humidity g/kg 70 total :11.4% 100 cold&wet: T < 12 C & humidity > g/kg 70 total :0% latitude [ ] Frequency (%) latitude [ ] Frequency (%) latitude [ ] Frequency (%) longitude [ ] longitude [ ] northern European and alpine countries are often cold and dry longitude [ ] southern European countries are often wet 0 10/10/2006 WNTE Evaluation 6

7 Influence of Widening the Zone contour label: coverage of average 2005 daily conditions (%) 4 80 delta humidity range [g/kg] minimum zone temperature [ C] 30 current proposal If the minimum zone temperature would be lowered to 5 C and the humidity range would be widened by 3 g/kg, about 65 % of the average European conditions could be covered (instead of ~ 20% with the current proposal) without the use of correction factors. 10/10/2006 WNTE Evaluation 7

8 Evaluation OCE monitoring approaches Requirements OCE monitoring approach: include all relevant operating conditions shall be able to detect defeat strategies compliant with PEMS 10/10/2006 WNTE Evaluation 8

9 Methodology Real life driving data 12 representative HDV applications : 45 hours driving from WHDC database - rigid truck (mot / rur / urb) - truck trailer 30t (mot / rur / urb) - truck trailer 40t (mot / rur / urb) - garbage truck (urb) - urban bus (rur / urb) Emission data EURO III: measurements on 24 engines 1 representative engine selected EURO V: only 1 engine measured (SCR concept) Emission model PHEM Measurements Emissions for real life driving Engine load patterns Engine emissions (in 1 Hz resolution) Evaluation of OCE monitoring approaches Covered percentage of HDV applications # monitored emission events max / min / average of emission events Comparison of monitored emission levels with total emission levels 10/10/2006 WNTE Evaluation 9

10 WNTE current draft Brake specific NOx emissions [g/kwh] / EURO III NTE control area engine power [kw] g/kwh = Infinite engine speed [rpm] Minimum sampling period: 30 seconds /10/2006 WNTE Evaluation 10

11 Distribution of NOx emissions urban bus / urban total WNTE 10/10/2006 WNTE Evaluation 11

12 Coverage of the draft WNTE (all HDV) (example: EURO III) Coverage total HDV driving in Europe: ~22% time ~33% NOx ~28% PM 10/10/2006 WNTE Evaluation 12

13 Modified control area based concepts Basic WNTE version: Coverage total HDV fleet (example EURO III): ~22% time ~33% NOx ~28% PM Alternative WNTE version #1: - unchanged control area - minimum sampling period reduced to 10s ~33% time ~53% NOx ~46% PM Alternative WNTE version #2: - enlarged control area - minimum sampling period reduced to 10s ~41% time ~63% NOx ~57% PM Problems: - highly transient operation not covered - interpretability of short emission peaks - PM mass measurement with filter not applicable 10/10/2006 WNTE Evaluation 13

14 Enlarged WNTE control zone % percentile of cumulative engine speed WHTC cycle % max power Engine Torque [Nm] modified NTE Control Area 500 PM carve out 20% max torque 20% max power Engine speed [rpm] 10/10/2006 WNTE Evaluation 14

15 Alternative approach: Work window Method: Total driving time is measured and evaluated Calculation of [g/kwh] averaged over a fixed amount of engine work ( work window ) engine power [kw] engine power [kw] cumulative positive engine work [kw] cumulative positive engine work [kwh] fixed work window NOx [g/s] NOx [g/s] cumulative NOx emissions [g] cumulative NOx emissions [g] time [s] time [s] 0 variable time window variable time window 10/10/2006 WNTE Evaluation 15

16 Work window based emission events instantaneous NOx emissions [g/min] work-window events NOx [g/kwh] W WHTC 5 instantaneous NOx emissions [g/h] work window based NTE events NOx [g/kwh] time 10/10/2006 WNTE Evaluation 16

17 Method: Alternative approach: CO 2 specific Total driving time is measured and evaluated Calculation of [g/kg CO 2 ] averaged over a fixed amount of emitted CO 2 ( CO 2 window ) Coverage total HDV fleet (example EURO III): ~99% time ~99% NOx ~99% PM Features of work window and CO 2 specific method: - all relevant operation conditions covered - classification of emission events possible (unavoidable high or defeat strategy ) if boundary conditions for test trip are well defined - PM mass measurement with filter is applicable 10/10/2006 WNTE Evaluation 17

18 Alternative approach: CO 2 specific Extra advantages CO 2 specific method: - No tricks needed to prevent excessive emissions in [g/kwh] at low loads - Less sensitive to ambient conditions - No ECM, kw or engine speed data necessary - Less sensitive for possible PEMS flow measurement errors 10/10/2006 WNTE Evaluation 18

19 Alternative approaches: CO2 specific methods CO2 specific NOx emissions [g/kg] / EURO III engine power [kw] engine speed [rpm] 10/10/2006 WNTE Evaluation 19

20 Alternative approaches: CO2 specific methods within WNTE engine map and 30' window within WNTE engine map and 30' window 120.0% 120.0% relative to emissions within the WNTE ambient conditions zone 100.0% 80.0% 60.0% 40.0% 20.0% NOx mass / work NOx mass / CO2 mass relative to emissions within the WNTE ambient conditions zone 100.0% 80.0% 60.0% 40.0% 20.0% THC mass / work THC mass / CO2 mass 0.0% all ambient conditions WNTE ambient conditions zone wet zone hot&wet zone hot and hot&dry zone 0.0% all ambient conditions WNTE ambient conditions zone wet zone hot&wet zone hot and hot&dry zone 10/10/2006 WNTE Evaluation 20

21 Comparison OCE monitoring approaches OCE monitoring approach coverage of relevant operating conditions unavoidable high emissions excluded feasibility with PEMS (*) ECU data necessary WNTE draft WNTE + 10s minimum sampling period yes yes 10s + enlarged control area o yes Alternatives Work window Compliance factor based on CO 2 specific emissions WNTE + minimum sampling period & work window for averaging of emission events + + o yes no yes (*) incl. filter-based measurement of PM emissions 10/10/2006 WNTE Evaluation 21

22 Summary I Findings are based on a large set of driving conditions from the WHDC database & emission data from ARTEMIS + COST D.A.CH.-NL (only one EURO V HDV): All approaches have specific advantages and disadvantages The actual proposal with a 30 second sampling period covers ~30% of European HDV emissions (large gaps especially in urban and rural driving) > no large additional value to existing type approval Only ~20% of the European weather conditions are covered without the use of correction factors Reducing the minimum temperature from 12 C to 5 C & widening the humidity range by 3 g/kg, leads to a much better coverage of weather conditions (65% instead of 20%) 10/10/2006 WNTE Evaluation 22

23 Summary II PM mass measurement with filter is not applicable for control area based approaches An alternative with 10 second sampling and enlarged control area covers ~55% of European HDV emissions, but transient and low load urban driving is still not covered > reasonable additional value to existing type approval The work window based approach and the CO 2 specific approach cover all relevant driving situations > large additional value to existing type approval The CO 2 based approach showed lower sensitivity to operating + ambient conditions and does not need measurement of engine work PM mass measurement with filter would be applicable 10/10/2006 WNTE Evaluation 23

24 Summary III At least for work window and the CO 2 specific approach further boundary conditions for the test trip would have to be defined The test trips and the evaluation should be divided at least into urban driving and highway driving The measured EURO V vehicle would have failed all OCE approaches due to increased emission levels after highly transient load changes and with inactive SCR in low loads; although the overall emission level was low (on average < 2g/kWh but scattering from 0.5 to 8 g/kwh) Without introducing OCE approaches EURO V and VI may have high NOx emission levels in several urban driving conditions which frequently occur 10/10/2006 WNTE Evaluation 24

25 Open questions Policy questions to define the boundary conditions: Shall OCE monitoring cover the thermal management of the engine and the exhaust gas after treatment too (e.g. cool down of SCR in stop&go)? If yes, low load driving has to be included in the trips Shall future HDV have low NOx emissions also in very unfavourable traffic situations (e.g. highly transient conditions)? If yes, the control area based approach is not suitable Feasibility and costs for manufacturers should be considered too Technological question: How can particulate mass be measured comparable to the type approval with filter method? 10/10/2006 WNTE Evaluation 25

26 Thank you for your attention! 10/10/2006 WNTE Evaluation 26

27 Backup Slides 10/10/2006 WNTE Evaluation 27

28 HDV mileage distribution country / weighting factor share on total HDV mileage mix GER NL A 100.0% 82.3% 10.6% 7.1% motorway 10.9% 9.2% 22.1% 13.5% rigid truck rural 11.0% 10.9% 12.1% 10.4% urban 7.7% 8.1% 5.2% 7.2% motorway 13.9% 14.2% 9.9% 15.7% truck&trailer (GVM: 30t) rural 5.2% 5.4% 3.4% 4.4% urban 2.8% 2.8% 4.0% 2.0% truck&(semi)trailer (GVM: 40t) motorway rural urban 31.4% 10.9% 3.2% 32.5% 11.5% 2.2% 22.9% 8.2% 10.3% 31.4% 8.8% 4.0% garbage truck urban 0.4% 0.4% 0.3% 0.4% urban bus rural urban 1.1% 1.5% 1.2% 1.6% 0.7% 1.1% 0.2% 2.0% TOTAL 100.0% 100.0% 100.0% 100.0% 10/10/2006 WNTE Evaluation 28

29 Cumulative NOx emissions truck + semitrailer 40t / motorway total WNTE 10/10/2006 WNTE Evaluation 29

30 WNTE control area + variants Euro III NOx NOx [g/kwh] [g/kwh] overall maximum overall weighted average overall minimum 0.00 overall maximum overall weighted average overall minimum total trip (overall weighted) WNTE event total trip (overall weighted) NTE event (10s minimum sampling period) NOx [g/kwh] total trip (overall weighted) overall maximum overall weighted average overall minimum NTE event (enlarged control area + 10s minimum sampling period) 10/10/2006 WNTE Evaluation 30

31 WNTE control area Euro III minimum sampling period: 30s rigid truck / mot rigid truck / rur rigid truck / urb brake specific emissions [g/kwh] truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile urban bus / urb 10/10/2006 WNTE Evaluation 31

32 WNTE control area variants Euro III WNTE events / NOx brake specific emissions [g/kwh] minimum sampling period: 10s rigid truck / mot rigid truck / rur rigid truck / urb truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile urban bus / urb 10/10/2006 WNTE Evaluation 32

33 WNTE control area variants Euro III WNTE events / NOx brake specific emissions [g/kwh] enlarged control area minimum sampling period: 10s rigid truck / mot rigid truck / rur rigid truck / urb truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile urban bus / urb 10/10/2006 WNTE Evaluation 33

34 Work Window approach #1 Euro III rigid truck / mot brake specific emissions [g/kwh] rigid truck / rur rigid truck / urb truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile urban bus / urb 10/10/2006 WNTE Evaluation 34

35 Work Window approach #3 Euro III brake specific emissions [g/kwh] rigid truck / mot rigid truck / rur rigid truck / urb truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile urban bus / urb 10/10/2006 WNTE Evaluation 35

36 CO 2 based compliance factor Euro III Compliance Factor [-] % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile rigid truck / mot rigid truck / rur rigid truck / urb truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur urban bus / urb 10/10/2006 WNTE Evaluation 36

37 WNTE control area + variants - Euro V NOx NOx [g/kwh] [g/kwh] total trip (overall weighted) overall maximum overall weighted average overall minimum WNTE event 0.00 total trip (overall weighted) 0.04 overall maximum overall weighted average overall minimum NTE event (10s minimum sampling period) NOx [g/kwh] total trip (overall weighted) overall maximum overall weighted average overall minimum NTE event (enlarged control area + 10s minimum sampling period) 10/10/2006 WNTE Evaluation 37

38 WNTE current draft 8.0 Emission events detected for the EURO V (40t truck trailer) brake specific NOx emissions [g/kwh] % 20% 40% 60% 80% 100% percentil Total range of emissions with inactive SCR Total range of emissions with active SCR Only 3 events (total duration: 120s) within seconds of measurements 10/10/2006 WNTE Evaluation 38

39 WNTE control area variants - Euro V NOx event [g/kwh] NOx event [g/kwh] % 20% 40% 60% 80% 100% percentil 0.0 0% 20% 40% 60% 80% 100% percentil NOx event [g/kwh] NOx event [g/kwh] % 20% 40% 60% 80% 100% percentil 0.0 0% 20% 40% 60% 80% 100% percentil 10/10/2006 WNTE Evaluation 39

40 Alternative approach: Work Window Euro V Approach 1: W_WHTC Approach 2: 0.5*W_WHTC Approach 3: WHTC; Pmin=4% Approach 1: W_WHTC Approach 2: 0.5*W_WHTC Approach 3: WHTC; Pmin=4% NOx [g/kwh] NOx [g/kwh] % 20% 40% 60% 80% 100% quantil 0.0 0% 20% 40% 60% 80% 100% quantil 10/10/2006 WNTE Evaluation 40

41 Alternative approach: CO 2 Euro V NOx CO HC PM 3.0 NOx CO HC PM Compliance Factor [-] Compliance Factor [-] % 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% percentil percentil 10/10/2006 WNTE Evaluation 41

42 Work Window approach #1 Euro V sim brake specific emissions [g/kwh] rigid truck / mot rigid truck / rur rigid truck / urb truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur urban bus / urb % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile 10/10/2006 WNTE Evaluation 42

43 Work Window approach #3 Euro V sim brake specific emissions [g/kwh] % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile rigid truck / mot rigid truck / rur rigid truck / urb truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur urban bus / urb 10/10/2006 WNTE Evaluation 43

44 CO 2 based Euro V (simulated engine) rigid truck / mot rigid truck / rur rigid truck / urb Compliance Factor [-] % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% quantile truck+trailer 30t / mot truck+trailer 30t / rur truck+trailer 30t / urb truck+semitrailer 40t / mot truck+semitrailer 40t / rur truck+semitrailer 40t / urb garbage truck / urb urban bus / rur urban bus / urb 10/10/2006 WNTE Evaluation 44

45 WNTE limits WNTE limits for EURO III engines EURO III ETC limit [g/kwh] WNTE limit [g/kwh] NOx OICA proposal 04/ OICA proposal 06/ PM OICA proposal 04/ OICA proposal 06/ HC CO WNTE limits for EURO V engines EURO V NOx PM ETC limit [g/kwh] WNTE limit [g/kwh] OICA proposal 04/ OICA proposal 06/ OICA proposal 04/ OICA proposal 06/ HC CO /10/2006 WNTE Evaluation 45

46 Alternative approach: CO 2 specific 1. Assessment of the CO 2 -specific emission behaviour in the type approval cycle TA based on the according emission limits: TA [g emissions /g CO2 ] = (emission limit) transient TA cycle [g/kwh] (carbon content) fuel[ ] 190[g/kWh] 0, Determination of the CO 2 specific emission events during the OCE monitoring OCE : Boundary constraint: a) In the OCE testing the same fuel has to be used as in type approval test b) The emission events OCE are calculated by averaging the CO 2 specific emissions over periods fixed by the amount of CO 2 emitted in the type approval test: OCE [g emissions /g CO2 ] = (mass CO2) transient TA cycle (mass CO (mass emissions) 2 ) transient TA cycle [g] OCE test [g] 10/10/2006 WNTE Evaluation 46

47 Alternative approach: CO 2 specific 3. The considered OCE test complies with the regulations, if all compliance factor events CF OCE (calculated by division of the CO 2 specific emission events in the OCE monitoring OCE by the constant CO 2 -specific emission behaviour in the type approval cycle TA ) are lower or equal the defined limit for the compliance factor for passing the OCE regulations CF Fail : CF OCE = OCE TA! CF Fail 10/10/2006 WNTE Evaluation 47

48 Reasons for HDV OCE monitoring Example: 1 manufacturer, 3 emission standards EURO I EURO II EURO III NOx [(g/h)/kw_ratedpower] Pe/P_rated n_norm Nox[(g/h)/kW_ratedpower] Pe/P_rated n_norm 1.2 NOx[(g/h)/kW_ratedPower] Pe/P_rated n_norm /10/2006 WNTE Evaluation 48

49 Reasons for HDV OCE monitoring Only one engine measured (SCRconcept) BS NOx [g/kwh] type approval limit Inactive SCR system (low catalyst temperature) type approval measured 2 real world highway real world city 0 Pre EURO EURO I EURO II EURO III EURO V 1993/ / / /09 10/10/2006 WNTE Evaluation 49

50 Current WNTE control zone % percentile of cumulative engine speed WHTC cycle % max power Engine Torque [Nm] NTE Control Area PM carve out % max torque 30% max power Engine speed [rpm] 10/10/2006 WNTE Evaluation 50

51 European driving data Basis of the analysis was the European part of the WHDC database, used for the development of a Worldwide Harmonised Heavy-Duty Engine Emissions Test Cycle No of vehicles vehicle category gross vehicle mass in kg rated power in kw distance driven in km motorway rural urban total 1 coach garbage truck rigid truck 5600 to to trailer/semitrailer truck to to urban bus to to total /10/2006 WNTE Evaluation 51

52 Percentage of driving time in WNTE zone percentage of time in NTE area related to driving time No time window vehicle category motorway rural urban coach 51.1% 36.2% 19.1% garbage truck 45.9% rigid truck 62.7% 45.1% 25.8% trailer/semitrailer truck 50.7% 44.6% 26.8% urban bus 32.2% 25.0% percentage of time of >= 30 s events in NTE area related to driving time 30 s time window vehicle category motorway rural urban coach 24.2% 4.2% 0.0% garbage truck 15.0% rigid truck 38.6% 13.7% 1.5% trailer/semitrailer truck 30.6% 16.5% 2.1% urban bus 3.6% 1.1% 10/10/2006 WNTE Evaluation 52

53 Percentage of driving time in WNTE zone percentage of time of >= 20 s events in NTE area related to driving time 20 s time window vehicle category motorway rural urban coach 29.8% 9.8% 0.0% garbage truck 20.2% rigid truck 44.1% 17.7% 3.0% trailer/semitrailer truck 36.4% 22.5% 4.0% urban bus 8.1% 2.9% percentage of time of >= 10 s events in NTE area related to driving time 10 s time window vehicle category motorway rural urban coach 37.0% 19.9% 2.2% garbage truck 28.8% rigid truck 52.0% 27.2% 7.8% trailer/semitrailer truck 43.2% 32.7% 10.2% urban bus 16.5% 8.7% 10/10/2006 WNTE Evaluation 53

54 Distribution of the duration of NTE events 100% 90% cum frequency 80% 70% 60% 50% 40% 30% veh 3, motorway veh 3, rural veh 3, urban 20% 10% 0% duration of NTE events in s 10/10/2006 WNTE Evaluation 54

55 Distribution of the duration of NTE events 100% 90% cum frequency 80% 70% 60% 50% 40% 30% veh 6, motorway veh 6, rural veh 6, urban 20% 10% 0% duration of NTE events in s 10/10/2006 WNTE Evaluation 55