Study On The Method Of Reducing The Emission Of Pollutants In The Cold-start Stage Of Light-duty Gasoline Vehicle

At present,the control of vehicle emission is the key to control the overall emission of gasoline engine.Through a large number of data and data analysis,one of the important factors that lead to high emission of gasoline engine pollutants at cold start is the difficulty of gasoline evaporation,resulting in lower gasoline combustion efficiency and poor emission effect.Therefore,it is a good measure to reduce the emission of pollutants by increasing the evaporation efficiency of gasoline.In order to improve the efficiency of gasoline evaporation,a scheme is proposed to improve the intake air temperature quickly: a car heater which can quickly heat the air intake air is studied.The preheating of the air can improve the temperature of the mixture of oil and gas,improve the efficiency of gasoline evaporation,improve the burning status of the gasoline,and reduce the emission of the pollutants.In the initial engine bench test,a bench test was carried out in parallel with the traditional heater and the engine intake pipe.In the experiment,the effect of the cold start emission of gasoline engine at different intake temperatures was discussed.The test results show that with the increase of intake temperature,the release of HC and CO of gasoline engine is reduced to a certain extent,and the minimum discharge effect can be obtained at the temperature of 70 degree C.In order to reduce the emission of pollutants more effectively,the temperature of cold air in the induction intake pipe can be improved.In order to effectively reduce the emission of the engine at cold start and improve the combustion quality in the corresponding working condition,the traditional heater is connected with the engine intake pipe to achieve a faster heating effect,and the computational fluid dynamics software is used for the combustion process in the process of testing.The specific data of the fuel evaporation is calculated.It is found that the intake temperature is closely related to the fuel evaporation and has the greatest impact on the emission reduction.At the same time,it is found through the data that the increase of the injection pressure can also affect the evaporation effect,and then reduce the emission of HC and CO in the emission,and optimize the heater structure based on the strategy of rapid heating.A fast air heater is developed to connect the engine with the engine intake pipe into a part of the engine intake system.The experimental results show that the heater can reach a satisfactory initial inlet temperature for 32 seconds.After a few minutes the engine starts,the intake temperature can remain high,making HC and C under cold start.The emission of O is improved effectively.