Research And Simulation Optimization Of Ethanol-fueled Engine With Diesel Micro Pilot Injection Ignition

Compression ignition engines are the main power source for commercial transportation,especially for ships.The current commercial compression ignition engine is mainly diesel-based,with advantage of high efficiency and durability.However,diesel engine has a reliance on fossil fuel,causing serious emissions problems.Port-injected ethanol-fueled engine with micro-pilot diesel induced ignition(MPII)enables little reliance on fossil fuel,and can also achieve very low soot emissions and low NOx emissions.However,it faces a more serious problem of carbon monoxide and unburned hydrocarbon emissions.Domestic and foreign researches on the ignition mode of diesel-ethanol MPII mainly focused on experimental exploration with rare simulation research.In this study,the application of diesel-ethanol MPII in compression ignition engine was experimentally verified and simulated.The experiment proved the practicability of combustion mode of diesel-ethanol MIPP in compression ignition engine,and found that appropriate early injection time can reduce carbon monoxide and soot emissions.Through the optimization of simulation,the optimized combustor shape,injector orifice taper angle and fuel injection timing are obtained,and the problem of over-high unburned hydrocarbon and carbon monoxide emissions from diesel-ethanol MPII engine is well controlled.Compared with the original condition,unburned hydrocarbon emissions decreased by 96.68% and carbon monoxide emissions decreased by 94.64% at the expense of a slight increase of nitrogen oxides emissions by 12.01% and a decrease of 0.3% in thermal efficiency of the engine.