The Influence of Rail Pressure and Injection Timing on the Performance of a China Ⅵ Diesel Engine
To optimize the performance of diesel engine,based on a high-pressure common rail inline four-cylinder diesel engine equipped with a complete China Ⅵ aftertreatment system,the load characteristics of the diesel engine were studied.On this basis,the effects of rail pressure and injection timing on the performance of the diesel engine were studied.The results show that the ideal fuel consumption and emission of diesel engine can be achieved by appropriately smaller rail pressure and earlier injection timing.Rail pressure and injection timing have little effect on HC emissions.Rail pressure has a great influence on fuel consumption,exhaust temperature,NOx emission and CO emission of diesel engine,and it is more sensitive at medium and large loads.With the rail pressure increased by 57 MPa,fuel consumption and exhaust temperature of diesel engine decrease by 16.1 g/(kW-h)and 63 ℃ respectively,NOx emission increases by 663 × 10-6 and CO emission decreases by 785 × 10-6.The injection timing has a great influence on the smoke level and diesel oxidation catalyst(DOC)front-end temperature T4,diesel particulate filters(DPF)front-end temperature T5 and selective catalytic reduction(SCR)front-end temperature T6,and is more sensitive at low loads.With the injection timing advanced by 6.0°,the smoke level decreased by 0.43％.T4,T5 and T6 peaks occur at a rail pressure of 76 MPa and an injection timing of 7.5° before top dead center,with temperatures of 315.3,338.4 and 329.3 ℃ respectively.
万方数据
维普
