内燃机示功图误差修正的热力学方法

A STUDY OF A NEW METHOD FOR ERROR CORRECTION IN CYLINDER PRESSURE MEASUREMENTS

本文通过计算机模拟,研究了内燃机拖动过程多变指数n,以及n与比热比κ之比与缸内传热状态的关系,研究了示功图热力分析中的主要误差对计算的n和n/κ的影响,详细地分析了热力学损失角的各种影响因素,并导出了标定上止点的两转速拖动示功图法。综合上述研究,本文提出了实用的示功图误差的综合修正方法。

In this paper the effects of heat transfer in engine cylinder on the thermodynamic loss angle of TDC, the polytropic exponent n calculated under motoring conditions and the ratio of n to the isentropic index k have been studied by computer simulation. The influences of errors in the thermodynamic analysis of an engine indicator diagram on n and n/k have also been investigated. Finally, a new method has been developed for correcting errors in cylinder pressure measurements.