COMPARISON OF FULL FLOW DILUTION, PARTIAL FLOW DILUTION, AND RAW EXHAUST PARTICLE NUMBER MEASUREMENTS

Transcription

1 COMPARISON OF FULL FLOW DILUTION, PARTIAL FLOW DILUTION, AND RAW EXHAUST PARTICLE NUMBER MEASUREMENTS M. Yusuf Khan 1, Sagar Sharma 1, Chet Mun Liew 1, Abhay Joshi 1,Daniel Barnes 1, Nathan Scott 1, Benjamin Mensen 1, Sam Cao 1, Yang Li 1, Montajir Rahman 2 1 Cummins Inc. 2 HORIBA Automotive Test Systems 21 st ETH-Conference on Combustion Generated Nanoparticles Zürich, Switzerland June 19 th to 22 nd 2017

2 Background Current EURO regulations allow Full flow & Partial flow dilution for PN measurements Studies have shown up to ±15% difference between CVS and Partial Flow Due to such variation, BSPN design target is set at least 50% lower than standards Most of the engine development occurs in raw test cells. Thus, there is a need of an instrument that can make PN measurement directly from raw exhaust HORIBA MEXA-2100 Solid Particle Counting System (SPCS) was identified which is compliant to PMP and can also measure raw PN emissions Therefore, Demo was conducted at Cummins Technical Center, Columbus, USA to evaluate the performance of the instrument 2

3 Overview of the HORIBA-2100 SPCS Compliant to EU regulation requirements Additional Dilution sampling unit (DSU) for raw PN measurements (Different PCRF values) Can operate in the test cell temp. up to 45 C (113 F) Can handle up to 500 C of exh. Temp. and 100 kpa exh. Back press. 4 m heated sampling line Integrated Cyclone to remove particle larger than 2.5 µm CPC calibration up to 10,000 #/cm 3 (TSI). Horiba internally confirmed linearity up to 30,000 #/cm 3 with R 2 > 0.99 Front View Rear View Heated PTT DSU Probe 3

4 Objectives PHASE 1: Evaluate Repeatability, Short-term Reproducibility and the Impact of PCRF Selection for HORIBA 2100 SPCS PHASES 2-5: Compare RAW or CVS against PFSS or CVS for DPF & non-dpf engines PHASE ENGINE DPF PN # Level HORIBA Location APC* Location (Ref.) 1-2 A NO RAW PFSS 3 B NO CVS CVS 4 C YES RAW CVS 5 D YES CVS CVS *APC: AVL PARTICLE COUNTER 4

5 PHASE 1: Experimental Setup Test Cell Location Cummins Technical Center (CTC), Columbus, USA Test Cell Type Engine A Raw Transient Cummins 8.9 L, 380 HP,6 Cylinder IL, SN: *****143 AT: DOC + SCR only Test Cycles NRTC (51), RMCC1/NRSC (26) Instruments HORIBA MEXA-2100 SPCS APC(SN 285) Location Dilution ratio Inside the Test Cell 202(RAW EO & SO) Test Cell 202 (PFSS SO) DSU:10; PND1:10,50,100; PND2:15 PFSS:~15 (avg. NRTC); PND1: 100, PND2: 10 Engine with DPF was not used to exclude the impact of DPF conditioning on PN concentration 5

6 Repeatability (NRTC) PCRF Values PHASE 1: Repeatability 5.0% 4.0% HORIBA Repeatability RAW -SO PCRF Values RAW -EO Repeatability of HORIBA varied from %, respectively on NRTC cycles. 3.0% 2.0% 1.0% Insignificant difference in repeatability of HORIBA due to change in sampling location 0.0% SO (4) SO (4) SO (3) SO (3) SO (5) EO (6) EO (5) EO (5) Horiba Location (No. of repeats) 0 Insignificant difference in repeatability due to change in PCRF values of HORIBA Repeatability of APC varied between % at PFSS SO 6

7 NRTC BSPN (#/BHP-HR) PHASE 1: Short-term Reproducibility 6E+13 5E+13 RAW -SO RAW- EO Short-term reproducibility at SO was 1.8% 4E+13 3E+13 Short-term reproducibility at EO was 3.5% 2E+13 1E+13 0 SO (4) SO (4) SO (3) SO (3) SO (5) EO (6) EO (5) EO (5) HORIBA Location (No. of Repeats) Short-term reproducibility of APC at PFSS SO was 1.2% 7

8 NRTC BSPN (#/BHP-HR) PHASE 1: Impact of PCRF Selection 6.00E+13 RAW SO RAW EO 5.00E E E E E+13 COV between dilution ratio settings ranging from ~2,000 to ~24,000 for RAW SO and RAW EO were 2.2% and 0.8%, respectively 0.00E (11) (8) (3) 2180 (6) (9) Dilution Ratio (No. of tests) 8

9 PHASE 2: Engine A w/o DPF (RAW vs. PFSS) Instrument SN PCRF Test Cell Location APC SO-PFSS HORIBA SPCS X SO-RAW 9

10 BSPN (#/BHP-HR) % Lower (HORIBA) PHASE 2: RAW vs PFSS RAW % Lower (HORIBA) 6.00E E E E E E % 16.0% 14.0% 12.0% 10.0% 8.0% 6.0% 4.0% 2.0% On average, RAW was ~13% lower than PFSS For NRTC, this average was ~14% and for RMCC1 was ~10% 0.00E+00 NRTC NRTC NRTC NRTC NRTC NRTC NRTC NRTC RMCC1 RMCC1 Test Cycles 0.0% 10

11 PHASE 2: CVS (Historical) vs. PFSS vs. RAW PN NRTC BSPN (#/BHP-HR) HORIBA 6E+13 5E+13 4E+13 3E+13 2E+13 1E+13 Historical -4% This Study 7% -6% CVS PN measurements were 6% higher and 7% lower than RAW and PFSS (this study), respectively Historical PFSS PN measurements (different test cell) differ by 11% from this study PN 0 CVS (6) PFSS (8) PFSS (19) RAW (22) PN Systems Location (No. of tests) 11

12 PHASE 3: Engine B w/o DPF (CVS vs. CVS) Instrument SN PCRF Test Cell Location APC CVS Tunnel HORIBA SPCS X CVS Tunnel 12

13 BSPN (#/BHP-HR) % Difference PHASE 3: CVS vs E E E E+13 CVS CVS % Difference 25.00% 20.00% 15.00% 10.00% 5.00% % Difference is defined as the ratio of the difference between two BSPN values and the average of two BSPN values 3.00E % 2.50E E E E Test Cycle Number -5.00% % % % % On average, the % difference between two on different types of test cycles ranged between ~ -9% to 2% with average of -4.21% 13

14 BSPN (#/BHP-HR) COV PHASE 3: Historical vs. This Study 5.00E E E+13 COV This Study 10.0% 8.0% 6.0% Historical data was 13% and 8% higher than APC and HORIBA measurements from this study. 2.00E E E+00 Historical (126) AVL (8) HORIBA (8) NRTC Cycle (No. of Repeats) 4.0% 2.0% 0.0% In this study HORIBA showed better COV than APC (2.7% vs. 5.9%) 14

15 PHASE 4: Engine C w/ DPF (RAW vs. CVS) Instrument SN PCRF Test Cell Location APC CVS Tunnel HORIBA SPCS X SO-RAW 15

16 BSPN (#/BHP-HR) % Higher (HORIBA) PHASE 4: RAW vs E E+11 3E E+11 2E E+11 1E+11 CVS RAW % Higher (HORIBA) Test Cycle Number 35% 30% 25% 20% 15% 10% 5% 0% -5% -10% -15% -20% -25% -30% -35% On average, the RAW PN were 7.9±13.7 % Higher than CVS (Reference) PN measurements 16

17 BSPN (#/BHP-HR) by RAW 3E+11 RAW vs E+11 2E E+11 ±15 ±20 ±25 ±30 Out of 45 data sets: 56%, 78% and 87%, and 91% of RAW data were within ±15%, ±20%, ±25% and ±30% of the Reference, respectively 1E+11 1E E+11 2E E+11 3E+11 BSPN (#/BHP-HR) by CVS (Reference) 17

18 PHASE 5: Engine D w/ DPF (CVS vs. CVS) Instrument SN PCRF Test Cell Location APC CVS Tunnel HORIBA SPCS X CVS Tunnel 18

19 BSPN (#/BHP-HR) PHASE 5: CVS vs % Difference CVS CVS % Difference 2E % 20.0% 1.5E+11 1E % 10.0% 5.0% 0.0% On average, the % difference between APC and HORIBA at CVS was -16%±4% -5.0% 5E % -15.0% -20.0% Test Cycle Number -25.0% 19

20 REFERENCE LOCATION (CVS or PFSS) OVERALL COMPARISON 30.0% 25.0% 20.0% 15.0% 10.0% PN level PN level PN level PN level % 0.0% -5.0% -10.0% -15.0% -20.0% -25.0% CVS CVS RAW RAW ±15% -30.0% HORIBA CVS or RAW 20

21 Conclusions Instrument performed adequately under high Temp. (up to 460 C) & high Pressure (up to ~43 kpa) BSPN Repeatability was observed between % BSPN Reproducibility was 1.8% and 3.5% for SO and EO, respectively No impact on BSPN due to change in PCRF values At level Historical CVS vs. PFSS vs. RAW were within ~13% At level RAW measurements were 7.9±13.7% higher than CVS For RAW testing, on average, the APC and HORIBA were between ~ ±15% 60%, 84%, 93%, and 98% of all raw HORIBA measurements were within ±15%, ±20%, ±25%, and ±30%, respectively. 21