Pollution realtime mass measurement method for vehicle emission test

XIONG Zhikai1, WANG Fengjin2

(1.Jiangling Motor Co., Ltd., Nanchang 330001, China; 2.GETRAG(Jiang Xi)
Transmission Co., Ltd., Nanchang 330011, China)

Abstract: Aiming at exhaust pollution instantaneous mass not been directly measured by direct sampling measurement system in vehicle development emission test, SAO and trace CO2 analyzer were developed. SAO was used to real time measure dilution air flow rate. Through CVS flow rate subtracts dilution air flow rate, the vehicle exhaust gas flow rate can be calculated. Trace CO2 analyzer was used to real time measure CO2 concentration of diluted gas. Through computing the dynamic ratio of CO2 concentration of diluted gas with CO2 concentration of tailpipe exhaust gas, the vehicle exhaust gas flow rate also can be calculated. Then pollution instantaneous mass can be calculated through multiplying tailpipe pollution concentration with vehicle exhaust real time volume at the same time. The emission test results indicate that the emission measurement system which additional SAO or trace CO2 analyzer can efficiently measure vehicle pollution instantaneous mass.

Key words: constant volume sampling(CVS) system; direct sample measurement; SAO method; trace CO2 method