ME/柴油HCCI燃烧与排放特性的试验研究

he homogeneous charge compression ignition(HCCI) combustion operated with DME and diesel fuel blend was investigated on a modified single cylinder diesel engine. The experimantal work was carried out by using port fuel injection with pintle nozzle. The effects of fuel injection pressure, Inlet air preheating and CO2 addition in intake air on engine performance and emission characteristics were studied. The results show that port injection of diesel fuel with higher volatility DME with distillation temperature lower than ambient air temperature has the potential to improve both mixture formation and homogeneity as a result of DME flash boiling. It is also an effective way to control HCCI combustion and extend the engine operating range. Different proportion of CO2 addition in intake air allows further control of combustion timing and engine load. When the proportion of CO2 addition was increased from zero to 30%, the Brake Mean Effective Pressure (BMEP) was extended from 0.32MPa to 0.5MPa，and simultaneous reduction of NOx and soot was achieved while HC and CO emissions slightly increased.