Research On Emission Control Of Non-road Mobile Mechanical Diesel Engines

Non-Road Mobile Machinery(NRMM)is defined as any mobile machine powered by engine including comprises agricultural & farming machinery,construction machinery,engine group and many others.The emissions from NRMMs is it is one of the main sources of pollution same as road vehicles.Currently the application of non-road mobile machinery more and more widely,the emission control of NRMM is increasingly urgent needed.According to the statistics,the annual increase of domestic non-road diesel engine is200 million units accounting for one-fifth of the total diesel consumption.The emissions of NOx reach about two million tons per year.Rather than NRMM lags in emission control technology,so it has greater potential for emission reduction.This article focused on the parameters and structure of a 4-cylinder diesel engine are improved and optimized,and the experimental study is carried out.By optimizing the influencing factors of the fuel injection system,determining the tip of the injector and the opening pressure,select the fuel pump plunger diameter and cam lift to improve the fuel injection rate and fuel injection pressure.By decreasing the premixed combustion temperature and reducing the initial injection rate to reduce NOx emission.To optimize fuel injection advance angle,it is first to ensure fuel consumption.Under this premise,in order to achieve the purpose of environmental protection and energy saving,it should be reduced the fuel injection advance angle,reduced ignition delay,decelerated the rise speed of cylinder pressure and temperature,and reduced emission.The results showed that through optimizing new design of combustion system,fuel system and others,adopted ? convex type combustion chamber,injector stretched with a 1mm nozzle and 26 MPa injection pressure,fuel injection pump with 11 mm diameter plunger and12 mm cam lift,selected the best fuel injection advance angle for each condition,improved the combustion efficiency of diesel engines,decreased fuel consumption to ensure the diesel engine work process more reasonable,to decrease NOX,CH and PM,to significantly improve the economy and power of diesel engine,and new type engine has reached National III emission standard.