Research On Reducing Particulate Emissions Of TMPI Gasoline Engines

With the improvement of people’s living conditions,cars have gradually become people’s transportation means of daily life.China’s car ownership has increased year by year.And the affect the enormous car ownership has on the environment has become more and more critical.The main car exhaust pollutants include hydrocarbon,carbon monoxide,nitrogen oxides and particle,which cause serious damages to people’s health and ecosystem.Recently years people demand more and more on the air quality,and it’s critical to control the particles in the car exhaust pollutants.The Nation VI regulation comes forth as the most strict emission regulation.How to reduce the particle emission is the most challenging work for all the engine manufacturers.This paper researches on means to reduce the particle emission of one 2.0TMPI gasoline engine.The engine adopts inside-engine and outside-engine purification technology so as to meet the standards of Nation VI regulation requirements.Firstly the paper introduces the National VI Emissions Regulations and the emission requirements of TMPI gasoline engine particulate have been added.In order to meet the requirements of National VI Emissions Regulations,the factors that affect the generation of gasoline engine particulates are explained in detail.The concentration and quality of the mixture,the engine operation parameters,intake tumble,and fuel injection are analyzed to track the impact on particulate emissions,and then the improvement methods are proposed.The TMPI gasoline particulate control method mainly includes internal purification and external purification.The internal purification technology is based on improving the combustion process of the engine.It is a radical measure to control the particulate emissions of gasoline engines.It mainly includes high-quality automation injection technology,high tumble flow intake technology,and efficient thermal management technology(EGR technology,dual thermostat control technology,exhaust manifold integrated to Cylinder head technology)and low engine oil consumption technology.External purification technology is mainly gasoline particulate filter(GPF),which is mainly to capture particulates in the exhaust gas.Secondly the emission test of this 2.0TMPI gasoline engine shows that the particulate emission exceeds the limit value greatly,and the the maximum exhaust temperature is much higher than the design limit.It’s essential to keep the exhaust temperature under a certain reasonable level with adopting the integrated exhaust manifold to the cylinder cover.And with the assistance of CAE analysis to ensure every parts of the water jackets heat exchange index to meet the design requirement.Inner purification is mainly by means of improving the intake port tumble ratio and optimization of the layout of injector and utilizing the high tension piston ring to reduce the particulate emission.The out-engine purification is mainly using the chassis GPF to reduce the engine’s particulate emission.Finally the optimized engine installed onto the vehicle to run the Nation VI emission regulation test.The engine’s particulate emission PN/PM has all met the requirement.With further optimization of the calibration data,all air pollutant emission values are under the limit values.And even after the deterioration it can still met the requirements(≤70%).