快速压缩机漏气量的计算方法

Calculation of blow-by in rapid compression machine

以自主研发的快速压缩机为研究对象,对燃烧缸内可燃混合气的泄漏量进行了计算。由于密封不好和活塞速度较慢,快速压缩机出现漏气,混合气的泄漏量与压缩比和活塞的速度有关。作者利用已知的缸内压力-时间关系曲线,对活塞的有效漏气面积进行了计算,在根据燃烧时缸内压力变化关系曲线对燃烧缸的漏气量进行了计算。漏气量的计算可以实现对缸内压力曲线修正,同时也可以对燃料的低热值进行修正,研究结果有助于提高计算精度和准确分析燃烧特性。

The combustible mixture in the combustion chamber of a self-developed rapid compression machine is leaking significantly when the machine works because of the poor seal between the cylinder liner and the piston assembly and the slow piston speed. Depending on the compression ratio and the piston speed, the blow-by was studied. An equivalent leaking orifice area was calculated according to the measured in-cylinder pressure versus time curves during the compression-combustion-expansion processes, and then the blow-by amount can be comkuted. The blow-by calculation results can be used to compensate the measured in-cylinder pressure histories and correct the fuel lower heat value, that is helpful for improving the validity of the combustion behavior analysis.