Of Of Bj483 Europe Ii Diesel Engine Research And Development

NOx and PM are the main exhaust emissions of diesel engines. Emission reduction technologies include turbocharging, turbocharging with intercooling, exhaust gas recirculation (EGR), aftertreatment system etc.Based on the state of art in domestic and overseas research, a study on BJ483 diesel engine is done in consideration of domestic manufacturing techniques. Results show that with technologies of in-cylinder combustion process optimization and electronic-controlled EGR system (to reduce NOx emission), The engine not only meets Euro II emission standard, but also fulfills production consistency requirement.This thesis mainly introduces the development of in-cylinder combustion process optimization and electronic-controlled EGR system. For the in-cylinder combustion optimization, the matching of ports, combustion chamber, injection system and turbocharger is critical. Test results show that squish whirl intensity is well kept by the high whirl combustion chamber (reentrant shape) within a wide engine speed range, and the NOx emission is reduced sufficiently by fuel injection delay without deterioration of engine performance and smoke. The EGR system uses the acceleration pedal position signal as a load signal and the response characteristic of EGR system is greatly improved. A vacuum pressure sensor sends vacuum control feedback signal to ECU to trim output pressure value, so that a local closed loop control of EGR rate is fulfilled.This thesis also analyzes tolerance factors which affect emission consistency in detail, and suggests an effective method to control the acceleration pedal position signal. A brand-new concept of maximum NOx & PM state is introduced, and the engine consistency performance can be forecasted through tolerance experiments.