Harmonised and Non-road Cycles from

Transcription

1 Overview of Emissions on World- Harmonised and Non-road Cycles from the AECC Euro VI Programme Mr. G. Rickert AECC Technical Steering Committee AECC Technical Seminar on Heavy-duty Engine Emissions Brussels, 25 October 2007

2 Contents Introduction WHTC NRTC Steady-state cycles (WHSC and NRSC) Summary 2

3 AECC heavy-duty Euro VI test engine 6 cylinder 7.5 litre engine designed for US Common rail - Turbocharged - EGR - No modification to base engine calibration - No change to calibration or regeneration strategy. AECC emissions control system + Bosch advanced airless urea dosing system - Basic urea dosing system calibration for the ESC, ETC and WHTC - No specific calibration for other cycles. NOx sensor (optional) NOx sensor No thermal management. DOC Mixer SCR + ASC 1m mixing length between injector and SCR face. 3

4 PM vs NOx (ESC test) (Euro V & EEV data) PM g/kwh Euro III limits (<0.75dm 3 & >3000min -1 rated power speed) Euro III limits AECC Euro V tailpipe result Euro V limits Euro IV limits AECC Euro VI tailpipe result NOx g/kwh Source: KBA data, June 2002, January 2006, March

5 ETC and WHTC cycle comparison WHTC operates at lower speeds and loads than ETC. 800 ETC WHTC Powermap Torque (Nm m) Speed (rpm) 5

6 ETC and WHTC tests: CO & HC emissions for engine-out and tailpipe ETC, engine-0ut ETC, tailpipe WHTC, engine-0ut WHTC, tailpipe Engine Out 0.8 Engine Out CO [g/kwh h] Engine Out 90% conversion 79% conversion Euro V limit Tailpipe Tailpipe To otal HC [g/kw Wh] Engine Out Euro V NMHC limit 63% conversion Tailpipe 69% conversion Tailpipe 0.0 ETC WHTC (5 min hot soak, 10% cold weighting) 0.0 ETC WHTC (5 min hot soak, 10% cold weighting) 6

7 ETC and WHTC tests: PM emissions for engine-out and tailpipe ETC, engine-0ut ETC, tailpipe WHTC, engine-0ut WHTC, tailpipe Engine Out mg/kWh 0.60 Engine Out s [g/kwh] Particulate Mas % 99.7% conversion conversion Tailpipe Tailpipe Particula ate Mass [mg/kw Wh] Tailpipe Tailpipe 0.00 ETC WHTC (5 min hot soak, 10% cold weighting) 0.0 ETC WHTC (5 min soak, 10% cold weighting) 7

8 ETC and WHTC tests: NOx emissions for engine-out and tailpipe ETC, engine-0ut ETC, tailpipe WHTC, engine-0ut WHTC, tailpipe 2.0 Euro V limit NOx [g/ /kwh] Engine Out 86% conversion Engine Out 76% conversion 0.5 Tailpipe Tailpipe 0.0 ETC WHTC (5 min hot soak, 10% cold weighting) 8

9 Tailpipe cold and hot start WHTC results showing effect of hot soak period 3.0 Cold Start 5 min Soak 10 min Soak 20 min Soak No EGR or SCR at cold start Em missions [g/kwh] NOx THC CO PM*100 9

10 SCR temperatures for ETC and cold start WHTC WHTC Cold Start Test ETC Test Temperature at SCR inlet 400 ETC is a hot start test e [ C] Temperartur EGR valve starts operating after ~570s on cold start tests Urea injection for SCR started t operating after ~800s on cold start tests Time [s] 10

11 SCR temperatures for WHTC options WHTC Cold Start Test WHTC Hot Start After 5 min Soak WHTC Hot Start After 10 min Soak WHTC Hot Start After 20 min Soak Note: SCR inlet temperature plotted. The urea injection is triggered by an the average of the inlet & outlet temperatures over the SCR catalyst. Hence on the cold start test, the SCR temperature may be in excess of the 200 C threshold before urea injection is observed re [ C] 400 Urea injection for SCR started operating after ~80s on hot test after 5 min. soak test Urea injection for SCR re-started operating after ~490s on hot test after 10 min. soak Urea injection for SCR started operating after ~675s on hot test after 20 min. soak Temperatur 300 short period of urea injection around ~90s on hot test after 10 min. soak Note: EGR valve operated from the start on the hot tests EGR valve started operating after ~570s on cold start tests Urea injection for SCR started operating after ~800s on cold start t t Time [s] 11

12 Summary of WHTC composite results Test Procedure Emissions [g/kwh] THC NOx CO PM Engine Tail Conv. Engine Tail Conv. Engine Tail Conv. Engine Tail Conv. Out pipe Effy. Out pipe Effy. Out pipe Effy. Out pipe Effy. WHTC cold % % % % WHTC hot ( 5 min) % % % % 10% cold weighted % % % % (EU-composite WHTC) WHTC cold % % % % WHTC hot (10 min) % % % % 10% cold weighted % % % % WHTC cold % % % % WHTC hot (20 min) % % % % 10% cold weighted % % % % 14% cold weighted % % % % (US-composite WHTC) Hot NOx conversion efficiencies ~85%. PM reduction efficiencies i i >99.5%. 12

13 Continuous trace for NO 2 on the WHTC World Harmonised Transient Cycle (WHTC) nt [ppm] onstitue C Nitrogen Dioxide Engine Out: NO2 Post DPF: NO2 Tailpipe: NO Time [s] 13

14 Profile of nitrogen species through the emissions control system World Harmonised Transient Cycle (WHTC) s Concen ntration [p pm] Ave erage Ga Engine Out Post DPF Tailpipe Nitric Oxide Nitrogen Dioxide Nitrous Oxide Ammonia 14

15 WHTC and NRTC cycle comparison WHTC vs NRTC Cycle Comparison WHTC NRTC Powermap 400 Torque (Nm m) Speed (rpm) 15

16 Non-Road Transient Cycle Cold start t weighting factors: EU is 10%; US is 5%. Soak time between the cold and hot tests is 20 minutes. Cold start: EGR and low SCR inlet temperature for first 300s. Hot tests: SCR inlet temperature reaches 200 C after 60s WHTC Test NRTC Test (Hot tests) 400 Temp perature [ C] Time [s] 16

17 HC and CO for non-road transient cycle Total HC [g/kwh] WHTC ( 5 min) WHTC (10 min) WHTC (20 min) Europe ETC (hot) USA Japan JE05 (hot) NRTC (20 min) FTP (20 min) 2.00 CO [g/kwh] WHTC ( 5 min) WHTC (10 min) WHTC (20 min) Europe USA Japan JE05 (hot) NRTC (20 min) ETC (hot) FTP (20 min) 17

18 NOx and PM for non-road transient cycle NOx [g/kwh] WHTC (5 min) WHTC (10 min) WHTC (20 min) Europe USA Japan ETC (hot) FTP (20 min) JE05 (hot) Partial flow (MDLT) measurement system NRTC (20 min) Particulate Ma ass [g/kwh] WHTC ( 5 min) WHTC (10 min) WHTC (20 min) Europe ETC (hot) USA FTP (20 min) Japan JE05 (hot) NRTC (20 min) Note: PM limit for Stages IIIB & IV is 25mg/kWh. Average test result is <1mg/kWh 18

19 1.0E+13 Particle numbers measurements over non-road transient cycle cle 3 orders of magnitude reduction from engine-out emissions (4.66E+14/kWh cold NRTC; 4.71E14/kWh hot NRTC) 10E E+12 part icle/kwh 1.0E+11 10E E+10 19

20 NRTC composite results Test Procedure Engine Out Emissions [g/kw.h] THC NOx CO PM Tail Conv. Engine Tail Conv. Engine Tail Conv. Engine Tail pipe Effy. Out pipe Effy. Out pipe Effy. Out pipe NRTC cold cold % % % % NRTC hot hot (20 min) % % % % NRTC (EU) 10% cold wtd % % % % Conv. Effy. NRTC cold cold % % % % NRTC hot hot (20 min) % % % % NRTC (US) 10% 5% cold wtd % % % % No optimisation i was undertaken. - No change to engine calibration from US2007 HD basis. - One-shot system sizing: would be optimised for production. - Urea dosing was not optimised i for non-road cycles. - No thermal management strategy to improve cold NOx emissions. 20

21 HC and CO for steady-state tests THC [g/kw.h h] ETC wtd-whtc[20] ESC WHSC NRSC h] CO [g/kw ET C wtd-wht C[20] ESC WHSC NRSC 21

22 1.00 NOx and PM for steady-state tests.h] NOx [g/kw NRMM Stage IV NOx limit ETC wtd-whtc[20] ESC WHSC NRSC PM M, MDLT [mg/k kw.h] ET C wtd-wht C[20] ESC WHSC NRSC 22

23 Summary Over the EU-composite World Harmonised Transient Cycle, NOx emissions were 0.3g/kWh and PM emissions were 2mg/kWh. NOx conversion efficiency over the hot-start WHTC was similar to that for the ETC (85%). Cold start efficiency was lower as the EGR did not operate until 570s and the system did not reach minimum urea injection until 800s on cold tests. The system was not fully optimised; i there was no thermal management to assist cold start NOx emissions. The Non-Road Transient Cycle has higher speeds and loads than the WHTC, resulting in faster achievement of operating temperatures. Over the EU-composite Non-Road Transient Cycle, NOx emissions were 0.471g/kWh and PM emissions were 1mg/kWh. 23

24 Acknowledgements the OE engine manufacturer Bosch, urea dosing system supplier Yara International, urea supplier Ricardo UK and the AECC Members Thank you for your attention 24