Experimental Study On Parameters Of Test System For Exhaust Emission

With the steady growth of car ownership, energy and environmental problems brought by the automobile is becoming more and more prominent. Countries around the world have introduced gradually tightened emissions regulations to limit car emissions of pollutants. New emissions regulations not only limit requirements of further reducing the pollutants, and changed the test method. At the same time, higher and higher demands are also proposed on the emission test system precision and response speed. However, with the corresponding emission testing technology of related research is less. In order to solve this situation, combined with the requirements of the relevant emission regulations, the subject want to study the influence of test system parameters on the emission test result.This research topic is based on the full flow CVS emission test system and adopted control variable method by comparison with multiple sets of experiment research. In this paper, we study the influence law of environmental parameters on the emission test result, such as the intake air temperature and humidity, charge cooler temperature, intake air pressure and exhaust back pressure. we also study the influence law of the full flow CVS emission test system parameters on the emission test result. In the process of test, direct sampling method is used to measure gas pollutants, such as CO, THC and NOX, full flow dilute sampling method is used to measure the PM.The test results show that the influence of environmental parameters, such as the intake air temperature and humidity, charge cooler temperature, intake air pressure and exhaust back pressure,on the emission test results of CO, THC,NOX and PM are obvious. While the influence of the intake air pressure is small. The total dilution ratio of full flow dilute system depends on the Primary dilution ratio and secondary dilution ratio. The PM emissions of diesel engine increases with the increase of the total dilution ratio.This paper made a full theoretical research on Pollutant emissions regulations, forming mechanism, influence factors and the measurement method. After four test process, including the test design, test preparation, test execution and test result analysis, We got the law of influence of the test system parameters on the emission test result. The research results can be used to guide set the parameters of a engine emission test, so as to achieve the aim of reducing engine emission test results. At the same time, This research topic put forward a new method to control the engine emissions, combined the actual engine emission characteristics and the requirements of the emission regulations, Reasonably set the parameters to control the engine emissions, It has great practical value in regulations certification test.