柴油机燃烧室壁面积炭层及其表面瞬态传热

Deposits and Surface Instantaneous Heat Transfer on the Diesel Engine Chamber Wall

本文在一台单缸直喷式柴油机上，用快速响应表面热电偶首先测量了倒拖运行时缸玉清洁壁面不同位置的瞬态温度。接着，在经历一段时间的着火变工况运行后，当热电偶热结点覆盖有积炭层时，重复上述实验。结果表明，表面积炭后瞬态温度波动减弱，平均温度下降，由此计算得到的传热率峰值降低，峰值相位滞后。文章提出了一种定量计算燃烧室壁面积炭层厚度和积炭表面时态温度的方法，并依据测量数据给出了研究结果。

In this paper, measurements of instantaneous temperature at three locations on the clean cylinder head of a motored single cylinder D.I diesel engine have been performed by means of fast response surface thermocouples.Then the same measurements were repeated after an interval of firing runs operated at varied loads and speeds when the thermocouples were coated by a layer of deposits.The results showed that when the combustion chamber wall was coated with deposits, the measured temperature fluctuation and mean temperature decreased,the corresponding peakheat flux became lower and its phase tended to lag.The paper put out an analytical method to compute the deposit thickness and the instantaneous temperature of the deposit surface, and obtained the computing results.