Study On Development And Calibration Of Diesel Engine For Meeting State ⅣEmission Regulation

Tianjin Lovol engine Co.Ltd has finished a kind of275HP diesel engine type development which meet China state IV emission regulations for heavy truck.Based on this diesel engine,this issue made a kind of230HP diesel engine type development which meet state IV emission regulations for passenger vehicle and gave a technological flow study about the electronic control calibration.Based on the study of abroad diesel engine emission control technology route,this issue compared the characteristic between EGR plus DPF system and SCR system in after-treatment technology route. According to the real condition in China diesel engine market and company production resource, this issue finally chose the4valve plus high pressure common rail plus SCR after-treatment technology route.Based on the choose of SCR after-treatment route, this issue expressed the emphasis is reducing PM for engine emission control. According to the analysis of PM composition, this issue pointed out the main control factors for reducing PM combustion optimization,use of few sulfur content fuel and reducing lubrication oil consumption.According to obvious PM improvement after changing air valve oil seal,this issue pointed out current key control factor of reducing lubrication oil consumption is the quality reliability performance improvement of air valve oil seal.At the same time,according to the analysis of SCR usual conversion efficiency, this issue got the engine emission test (ESC、ETC、ELR)control target and gave a summary about ESC,ETC and ELR test engine calibration.Based on the compared analysis about structure and characteristic of the key part of SCR after-treatment system, this issue gave a summary and provided a reference for hardware selection in SCR parts.Based on the study of SCR after-treatment control system, this issue chose a advanced urea closed-loop injection control strategy which has good environment and control system adaptability. At the same time introduced the study method of main factors which influenced urea closed-loop injection,gave a summary how to calibrate the electronic control model. At last, according to the OBD regulations and diagnosis principle, this issue gave a OBD calibration summary, so had a full SCR emission control strategy and calibration technological flow.