Introduction of measurement technics regarding mass emissions and real time fuel consumption using direct exhaust gas flow meter

THAI Automotive Summit 2015 Introduction of measurement technics regarding mass emissions and real time fuel consumption using direct exhaust gas flow meter Masanobu Akita HORIBA, Ltd. 2015 HORIBA, Ltd. All rights reserved. 1

INDEX 1. Background 2. Conventional measurement method 3. Direct mass emission measurement 4. Test equipment and test system 5. Test results 6. Other applications 7. Summary

World Fuel Economy Targets Light-Medium Duty Vehicle; CO 2 emission criteria (1/28) CO2 weighted average (g/km) 200 Current (2015) 180 160 140 120 100 (201g/km) (140g/km) 2010 (169.9g/km) (130g/km) (145 g/km) (137.5g/km) (95g/km) 2020 (115.5g/km) (89 g/km) 2005 2010 2015 2020 Current EU CO 2 emissions based on NEDC and EURO5/6 procedures EU is more aggressive than USA/JAPAN EU requests 68-78g/km by 2025 2025

INDEX 1. Background 2. Conventional measurement method 3. Direct mass emission measurement 4. Test equipment and test system 5. Test results 6. Other applications 7. Summary

Conventional Fuel economy measurement method for light duty vehicle CVS method Combination of Dilute sampling using CVS and Gas concentration measurement using Gas analyzer CVS Measurement System Driver s aid (2/28) Chassis Dynometer Constant Volume Sampler(CVS) Diluted Gas Analyzer Test Automation system

Conventional Fuel economy measurement method for light duty vehicle CVS method (2/28) Combination of Dilute sampling using CVS and Gas concentration measurement using Gas analyzer CVS Measurement System Driver s aid Test vehicle is driven on a chassis dyno using driver s aid or auto driving system Diluted exhaust gas is stored in a sample bag which has constant volume Mass emissions are calculated from the concentration of the exhaust gas Fuel economy is calculated by the mass emissions and the driving distance

Fuel consumption calculation from mass emissions (3/28) Carbon Balance Method for fuel consumption 1 M M M FCB THC CO RCWF αexh M H + M C MCO M CO 2 Fuel THC CO CO 2 ( ) C C C t = Mass ( t) + Mass ( t) + Mass ( t) Mass Measurement of each emissions by CVS CO2 Mass = x Mass Emission = ρ C x ρx C x_ex V x_sam ex C 10 6 x_amb Gas Density Gas Concentration 1 1 DF V mix 10 6 Diluted Gas Volume Fuel economy is calculated by gas emissions and it is important to optimize not only fuel economy but also totally mass emissions

INDEX 1. Background 2. Conventional measurement method 3. Direct mass emission measurement 4. Test equipment and test system 5. Test results 6. Other applications 7. Summary

Development challenges of the automobile (4/28) Increasing of test patterns Test cycles of each countries JC08, FTP-75, NEDC, WLTC,,,, Demands from Each county Various Fuel, Low cost vehicle Increasing of measured gas compositions Regulation of gas emissions CO, NO x, THC, PM, PN Environmental law CO 2, GHG NH 3, Sulfur Compounds Efficient emission test is required on R&D of vehicles Optimization in engine test cell Instantaneous emission measurement linked with engine speed/torque

Importance of transient mass measurement Exhaust Flowrate[m 3 /min] CO 2 [%] THC[vol%C] NOx[%] 3.5 3 2.5 2 1.5 1 0.5 0 18 16 14 12 10 8 6 4 2 0 0.6 0.5 0.4 0.3 0.2 0.1 0 50 100 150 200 250 300 350 400 450 500 Time[sec] CO 2 CO2 Conc. Wet 0 50 100 150 200 250 300 350 400 450 500 Time[sec] THC THC Conc. 0 0 50 100 150 200 250 300 350 400 450 500 Time[sec] 0.07 0.06 0.05 0.04 0.03 0.02 0.01 Exh. Flow NOx Conc. 0 0 50 100 150 200 250 300 350 400 450 500 Time[sec] Example:FTP-75 CT Phase Most of regulated emissions are emitted in early stage of a test cycle CVS method basically measures average mass through the test cycle It is more effective to measure transient mass variation for optimizing fuel economy and emissions (5/28)

Proposal of Direct mass emission measurement Direct Mass Emission Measurement Transient variation is measured by combination Direct gas flow meter and analyzer (6/28) Change parameters, Improve parts Improve using Direct Mass Emission Efficiency optimize in engine bench After Treatment Engine Dyno Direct Exhaust Gas Flow Meter Direct Gas Analyzer Final regulation test is executed by CVS method

Direct mass emission measurement [1/2] Basic equation (7/28) m (t) =ρ C (t) x x x Mass Emission Gas Density Gas Conc. Q exh (t) Exhaust Flowrate CO2 conc.[ppm] 160,000 120,000 Exh. flow rate[l/min] CO2 mass[mg/s] 80,000 40,000 0 1,500 1,200 900 600 300 0 5,000 4,000 3,000 2,000 1,000 0 Gas conc. 0 20 40 60 80 100 120 140 160 Time[sec] Exh. Flowrate 0 20 40 60 80 100 120 140 160 Time[sec] CO 2 Mass Emission 0 20 40 60 80 100 120 140 160 Time[sec] Example of CO 2 Mass emission Gasoline E/G FTP75 CT ~160sec

Direct mass emission measurement [2/2] Actual equation (8/28) 1 273. 15 m x (t) = Mx Cx(t+ DTx) ( 1 CH 2O(t)) Qexh(t) Molecular Delay Time Water Correction 22. 415 293. 15 Mass Response Time Correction CO conc.[ppm] 1,500 1,200 Exh. flow rate[l/min] CO mass[mg/s] 900 600 300 0 300 250 200 150 100 50 0 2.0 1.5 1.0 0.5 0.0 Gas conc. 0 2 4 6 8 10 12 14 16 18 20 Time[sec] Exh. Flowrate 0 2 4 6 8 10 12 14 16 18 20 Time[sec] CO Mass emission 0 2 4 6 8 Time[sec] 10 12 14 16 18 20 Example of CO Mass emission Gasoline E/G FTP75 CT ~20sec

INDEX 1. Background 2. Conventional measurement method 3. Direct mass emission measurement 4. Test equipment and test system 5. Test results 6. Other applications 7. Summary

Test Equipment [1/2] Exhaust Volume Flow Meter (9/28) Ultrasonic Raw Exhaust Gas Flow Meter Principle Ultrasonic transit time method Advantages for the method No pressure loss No influence of compositions Wide measurement range Non Sampling 690mm HORIBA EXFM-ONE Exhaust gas flow Ultrasonic wave Measure the difference of the transit time

Test Equipment [2/2] Exhaust Volume Flow Meter Direct Exhaust Gas Analyzer (10/28) Compositions CO 2 CO THC NOx PN Principle Non Dispersive Infrared Detector(NDIR) Flame Ionization Detector (FID) Chemiluminescence Detector (CLD) Condensati on Particle Counter (CPC) Gas Flow Filter Analyzer F Cooler P HORIBA MEXA-ONE Exhaust pipe Exhaust gas (drain) Pump [Gas Concentration] PC

Evaluation Test System (13/28) Sync. / Control signal Test Automation System or After Treatment Exh. Flow Exh. Flow meter CVS Gas Analyzer (Dilute) Gas sample line Gas Analyzer (Direct) Direct Mass Measurement CVS Method Compare these 2 methods

Integrated operation system HORIBA ONE Platform[1/2] (11/28) MEXA-ONE CVS-ONE EXFM-ONE Existing Products 3 rd Party Products

Integrated operation system HORIBA ONE Platform[2/2] (12/28) Operation screen

Evaluated Engine/Vehicles (14/28) Items Specifications Engine A Vehicle A Vehicle B Engine DI Diesel DI Diesel Gasoline Engine displacement 1.6 L 1.4 L 1.5 L Injection system Common Common Port Rail Rail Injection Intake system TC IC TC IC N/A

INDEX 1. Background 2. Conventional measurement method 3. Direct mass emission measurement 4. Test equipment and test system 5. Test results 6. Other applications 7. Summary

Example of Real time Mass Emission[1/2] (15/28) THC [mg/s] CO [mg/s] CO 2 [mg/s] Speed [km/h] THC mass[mg/s] 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 ECE EUDC THC mass 0 200 400 600 Time[sec] 800 1000 1200 Vehicle A(DI Diesel) [NEDC Test cycle] CO 2 Mass emission is related with acceleration CO Emission is remarkable at High speed phase(eudc) THC Almost all THC is emitted at the beginning of the cycle

Example of Real time Mass Emission[2/2] (16/28) Speed [km/h] ECE EUDC Vehicle A(DI Diesel) [NEDC Test cycle] NOx ]mg/s] NO x Mass emission is increased stabilized phase after deceleration PN [#/s] PN Particle Number (#/s) contrastive with NOx is observed

Difference from CVS [1/2] (Integrated mass emissions) (17/28) CO2 2 [g/km] 240 210 180 150 120 90 60 CVS Direct Mass Difference ±2% CO 2 20% 15% 10% 5% 0% -5% -10% Test conditions Test1:Engine A(CI) ECE Test2:Engine A(CI) EUDC Test3:Vehicle A(CI) NEDC Test4:Vehicle B(SI) FTP75 HT 30-15% 0 Test1 Test2 Test3 Test4-20% CO [g/km] CO [g/km] 1.6 1.4 1.2 1 0.8 0.6 CO CVS Direct Mass Difference ±5% 20% 15% 10% 5% 0% -5% CO 2, CO CO 2 ±2% difference CO±5% difference in this tests 0.4-10% 0.2-15% 0 Test1 Test2 Test3 Test4-20%

THC [g/km] THC [g/km] 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 Difference from CVS [2/2] (Integrated mass emissions) THC CVS Direct Mass Difference ±5% 20% 15% 10% 5% 0% -5% -10% -15% (18/28) Test conditions Test1:Engine A(CI) ECE Test2:Engine A(CI) EUDC Test3:Vehicle A(CI) NEDC Test4:Vehicle B(SI) FTP75 HT 0.00 Test1 Test2 Test3 Test4-20% NO X [g/km] NOx [g/km] 0.24 0.21 0.18 0.15 0.12 0.09 0.06 NO x CVS Direct Mass Difference ±5% 20% 15% 10% 5% 0% -5% -10% THC, NO x THC±5% difference NO x ±5% difference in this tests 0.03 0.00 Test1 Test2 Test3 Test4-15% -20%

Correlation with CVS[CO 2 mass] (19/28) 250 200 y=1.028x - 1.570 R 2 =0.9996 y = 1.018x - 1.5703 R² = 0.9996 Test4 Direct mass[g/km] 150 100 Test1 Test2 Test3 Test conditions Test1:Engine A(CI) ECE Test2:Engine A(CI) EUDC Test3:Vehicle A(CI) NEDC Test4:Vehicle B(SI) FTP75 HT 50 0 0 50 100 150 200 250 CVS Bag[g/km] R 2 indicates a strong correlation between direct mass and CVS

Repeatability [CO 2 mass] (20/28) 160 140 120 Vehicle B Repeat test FTP-75 HT505sec Standard deviations CVS Bag 2.67 Direct mass 2.37 CoV within 2%! CO 2 [g/km] CO 2 [g/km] 100 80 60 40 20 CVS Bag Direct Mass 0 n1 n2 n3 n4 n5 n6 n7 Average

INDEX 1. Background 2. Conventional measurement method 3. Direct mass emission measurement 4. Test equipment and test system 5. Test results 6. Other applications 7. Summary

Other Application ~PEMS alternative in a cell~ (22/28) RDE(Real Driving Emissions) regulation requires to measure emissions(nox, PN(2017~)) using PEMS PEMS: Portable Emission Measurement System) HORIBA On Board System (PEMS) OBS-ONE However,,, Vehicles under development can not be driven on a normal road!

Other Application ~PEMS alternative in a cell~ Real World Regulation test for commercial cars Real Drive using PEMS (23/28) Chassis Cell R&D evaluation for development cars Simulation drive using direct emission measurement Vehicle for R&D Direct Exhaust Gas Flow Meter (Existing) Gas Analyzer

Challenge to easy measurement of fuel consumption (24/28) Fuel Flow Meter Need to modify a test vehicle Non real-time CVS Bag measurement with Carbon balance method Chassis Test Cell In-situ measurement Delay by dead time Dilute stream Challenge: Real-time, No modify, High response method

Principle of Proposed Method (25/28) Measure Real-time Fuel Consumption from Exhaust Flow rate and Air-to-Fuel Ratio(AFR) Air Exhaust Fuel AFR 1Exhaust = Air + Fuel From these 2AFR = Air / Fuel Fuel = 2 relations,,, Exhaust 1+AFR

EXFM-ONE integrates AFR Sensor inside Device Management Controller (DMC) (26/28) Ultrasonic Flow Controller Rear Front Easy replacement Ultrasonic transducer AFR Sensor Exhaust Flow

Fuel consumption(g) Measured by Exh. flow and AFR Correlation of Integrated fuel consumption 200 180 160 140 120 100 80 60 40 20 0 y = 1.0084x - 2.6403 R² = 0.9999 Vehicle A Idling Vehicle A Approx. 40km/h Vehicle A Approx. 60km/h Vehicle A Approx. 80km/h 0 20 40 60 80 100 120 140 160 180 200 Fuel consumption(g) Measured by Fuel flow meter Correlation with Fuel Flow Meter Fuel consumption(g) Measured by Exh. flow and AFR y = 1.031x - 3.563 R² = 0.9998 Correlation with CVS bag method Good correlation is observed for both conventional method 200 180 160 140 120 100 80 60 40 20 0 Idle Vehicle A Approx. 40km/h Vehicle A Approx. 60km/h Vehicle A Approx. 80km/h Vehicle B Approx. 15km/h Vehicle B Approx. 25km/h Vehicle B Approx. 50km/h 0 20 40 60 80 100 120 140 160 180 200 Fuel consumption(g) Measured by CVS-Bag Possibility to measure reliable fuel consumption (27/28)

INDEX 1. Background 2. Conventional measurement method 3. Direct mass emission measurement 4. Test equipment and test system 5. Test results 6. Other applications 7. Summary

Summary (28/28) Direct mass emission measurement technique is effective method for R&D of vehicles The usability of this measurement method was verified by comparing CVS method, and some good correlations and equivalencies suggested the potential of the method Direct mass emission is based on a raw exhaust gas measurement, and easy and in-situ real-time fuel consumption measurement is achieved by combination of exhaust flow meter and AFR sensor