灰分分布系数对柴油机性能的影响研究

Influence of Ash Distribution Coefficient on Diesel Engine Performance

通过构建柴油机耦合柴油机颗粒捕集器(diesel particulate filter,DPF)的一维热力学仿真模型,研究了灰分分布系数对柴油机性能的影响,并重点分析了灰分分布系数对柴油机系统热效率的影响。结果表明:炭载量为6 g/L,灰分量为33 g/L时,DPF压降和捕集效率随灰分分布系数增加而上升;随着灰分分布系数增大,柴油机转矩、缸内最最高燃烧压力及氮氧化物排放量均下降,碳烟排放量升高;灰分分布系数增加,柴油机有效燃油消耗率增加,DPF再生频率增加,包含柴油机热效率和DPF再生效率的柴油机系统热效率降低。单一地依靠DPF压降对主动再生时刻进行判定误差较大,且误差会随灰分量的增加呈现类指数增大。

By constructing an one-dimensional thermodynamic simulation model of diesel engine coupled with diesel particle filter(DPF),the effect of ash distribution coefficient on the performance of diesel engine was studied,focusing on the influence of ash distribution coefficient on the thermal efficiency of the diesel engine system.The results show that when the soot loading is 6 g/L and the ash loading is 33 g/L,the DPF pressure drop and filtration efficiency increase with the increase of the ash distribution coefficient.When the ash distribution coefficient increases,the diesel torque,the maximum pressure in the cylinder,and the NO x emissions decline,and the soot emissions increase.When the ash distribution coefficient increases,the engine brake specific fuel consumption and DPF regeneration frequency increase,and the engine thermal system efficiency that contains both diesel thermal efficiency and DPF regeneration efficiency decreases.Relying solely on the DPF pressure drop to determine the start of active regeneration have a large error,and the error increases with the increase of the ash loading.