Matching Study Of China Ⅲ Non-Road Diesel Engine Combustion System

With " Limits and Measurement Methods for Exhaust Pollutants from Diesel Engines of Non-road Mobile Machinery(China Ⅲ Ⅳ)" released,diesel engines of non-road mobile machinery in China will enter the Stage Ⅲ,and then Stage Ⅳ.The enterprises,who manufacture the non-road machinery diesel engines,face the fact that their products have to be optimized to meet the emission limits of the diesel engines of non-road mobile machinery in Stage Ⅲ.To help some enterprises in Shandong Province upgrade their products,the thesis focused on researching the Stage Ⅲ technical route,and had tried to apply the electronic control unit pump and high-pressure common-rail system to the non-road diesel engines.Below is the main work in the thesis:Built the test bench which included the dynamometer system,steady-state parameters acquisition system,emission test system,intake test system,transient parameters acquisition system and so on.Studied the application of electronic control unit pump and EGR system on the 4105 turbocharged diesel engine.In the study,the original straight-mouth ω combustion chamber was cornverted into the staged combustion chamber,the original mechanical fuel system was replaced by electronic control unit pump system,and the EGR system was applied.After the work above,the thesis optimized the pump plunger diameter,the injector and the length of the injector nozzle exposed in the combustion chamber,the pressure ratio and flow of supercharger,the position from which EGR taking exhaust in.Those matching experiments confirmed that the appropriate pump plunger diameter was 10mm,the 6-23 injector was selected,the length of the injector nozzle exposed in the combustion chamber was 3.6 mm,the bigger flow and pressure ratio supercharger was selected,the EGR system took the exhaust in from the manifold.Finally,the thesis calibrated the matched diesel engine.The calibration showed that 4105 turbocharged diesel engine with electronic control unit pump and EGR system can satisfy the emission requirements in Stage Ⅲ regulation for non-road diesel engine.Applied high-pressure common-rail system to the 4102 naturally aspirated diesel engine.In the study,the original straight-mouth ω combustion chamber was converted into the staged combustion chamber,the high-pressure common-rail system replaced the original mechanical fuel system,both the swirl rate of the cylinder head and the setting angel of injector were reduced,the injector was selected,the length of injector nozzle exposed in the combustion chamber was optimized.Those experiments confirmed that the parameters of the appropriate injector were 7 holes,0.14Mm hole diameter and 155° hole cone angel and the length of the injector nozzle exposed in the combustion chamber was 2mm.Based on the work above,the paper studied the impact of rail pressure and pilot injection on emissions and fuel consumption.Finally,the thesis calibrated the engine.The calibration confirmed that naturally aspirated diesel engine with high-pressure common-rail system can satisfy the emission requirements in Stage III regulation for non-road diesel engine.