柴油机非水冷却介质自然对流沸腾传热特性研究

A Study on Heat Transfer Performances of Free Convection

对于采用非水冷介质的高温冷却及少冷却柴油机的研究，目前尚需了解冷却介质温度的提高及冷却介质的性质差异，对柴油机的传热及零部件热状况的影响。本文模拟柴油机工作条件，对机油、柴油及不同配比的乙二醇水溶液等液体的自然对流沸腾传热特性进行了试验研究，揭示了各种因素对传热的影响，通过对试验数据的回归分析得出了３种非水冷却介质自然对流沸腾传热关系式。为机油、柴油及乙二醇水溶液用于柴油机高温冷却及少冷却提供了理论依据。

In order to study the high temperature cooling and low heat rejection diesels with non water coolants,it is necessary to find out the affections of teperature raising and properties changing of the coolants for the heat transfer in the diesels and thermal states of the parts.The paper simulating diesel engine work conditions,free convection boiling heat transfer performances were researched for an engine oil,a diesel fuel and ethylene glycol aqueous solutions with different composition as coolants,the effects of different factors were analysed for heat transfer,and the correlation expressions of free convection boiling heat transfer for the three kinds of non water coolants were obtainted by regress analysis using test data.The study provides a throretical basis for the diesel engines high temperature cooling and low heat rejection cooling using engine oils,diesel fuels and ethylene glycol aqueous solutions as coolants.