不同发动机热力损失角测试及影响

在D6114车用柴油机上进行上止点位移测试及基于压缩压力的上止点位置计算,分析各种方法测量误差及发动机运行条件对上止点位置的影响规律,对理想多变指数比对法和绝热压力修正法两种方法进行校核计算;进一步开展车用柴油机、车用汽油机和船用中速柴油机3种不同类型发动机的热力损失角测试与估算研究,确定不同机型热力损失角范围。结果表明:采用两种方法都可以较好地预测车用柴油机热力损失角,上止点曲轴转角测试误差不超过0.2°,其中绝热压力修正法计算更简单直接;车用柴油机的热力损失角较大,车用汽油机次之,而船用中速柴油机的热力损失角最小,并且受转速变化的影响较小。

Test of the thermal loss angle on different kinds of engine and its influence

The top dead center(TDC)position measurement and the calculation of TDC position based on compression pressure are carried out on D6114 vehicle diesel engine.Based on the error analysis of different measurements and the effects of engine operating conditions on TDC position,different thermal loss angle(TLA)methods between ideal multiple index comparison method and adiabatic pressure correction method are compared,and the TLA test and estimation of three different types of engines,including vehicle diesel engine,vehicle gasoline engine and marine medium speed diesel,are further carried out.The range of TLA calculated by different models is compared.The results show that the TLA of vehicle diesel engine can be well predicted and the test error of TDC is within 0.2°,and the adiabatic pressure correction method is simpler and more direct.The TLA of vehicle diesel is larger than that of vehicle gasoline engine,and the TLA of marine medium speed diesel is the smallest,which is less affected engine speed.