Experimental Research On The Influence Of Working Parameters And Dilution Ratio To Engine Emission

With the sustainable growth of car ownership, energy and environmental problems brought by the automobile are becoming more and more prominent. Countries around the world have launched strict emissions regulations and laws gradually to improve the demand for limit value of pollutant and precision and response speed of test method and test system, but the research for influences of the corresponding emission had fallen behind obviously. This subject researched the influences caused by the working parameters and dilution ratio on engine emission test results, hoping to puts forward some rational advices for improving the engine parameters.This paper adopted control variable method to conduct research by comparison with multiple sets on the base of full flow emission test system CVS. In order to eliminate the effects of the other factors beyond the research object and enhance the validity of the test, first studied the repeatability of the test; on the basis, researched influencing rules on engine emission test results,which are caused by the parameters of flow discharge test system,such as the intake air temperature and humidity, charge cooler temperature, intake air pressure, exhaust back pressure, the primary and secondary dilution ratio. The results showed that reducing charge cooler temperature and increasing exhaust back pressure can reduce the emissions of NOX; improving charge cooler temperature, reducing intake air temperature, increasing exhaust back pressure can reduce the emissions of Total Hydrocarbons THC, carbon monoxide CO and PM; and the PM emissions of diesel engine increases with the increasing of the total dilution ratio.This paper made a full theoretical research on pollutant emissions regulations and laws, forming mechanism, influence factors and the measurement method etc.. After four test steps, including the experiment design, preparation, execution and result analysis. we got the influence law of engine working parameters and dilution ratio to the emission test results, and provide theoretic foundation for improve the engine parameters. The research conclusions can be used to analyze test results in the engine emission test. Total dilution ratio should choose the minimum value under the condition of meet regulatory requirements. This can reduce the quality increase of PM in the process of test. So that test results can reflect actual emission level of engine.