发动机滑油散热系统性能研究

针对某型发动机滑油散热系统中换热器对环境散热量较大的情况,提出了实用的滑油换热器散热特性计算模型,推导了发动机的滑油吸热准则式,从而建立起一整套发动机滑油散热系统的性能计算的新方法。在理论分析的基础上,推导了换热器在实际运行状况下的NTU计算式。通过某型发动机的试验数据进行了校验,表明本文方法可以满足一般工程计算的要求,而且具有通用性,为计算滑油散热系统的性能和预测恶劣环境下滑油系统的散热能力提供了理论依据。

Investigation of Performance of an Engine Oil Cooling System

This paper establishes a new method of obtaining the performance of an engine oil cooling system.The method involves the equation of heat gain of the oil passing through an engine and performance calculations of oil heat exchangers.When the heat exchange between oil and ambient in the oil heat exchanger cannot be ignored,the complex heat transfer processes could be treated as two independent approaches,heat transfer from oil to cooling fluid as well as from coolant,to ambient.Each separate approach is a simple heat transfer problem for which an analytic solution can be acquired easily,and then the real outlet temperature value of oil is obtained by a linear combination correlation of these two solutions.Based on the theoretical analysis,a more effective NTU correlation of the heat exchanger is deduced under the operating condition.This method has been well verified by the experimental data of an engine and can be used to calculate the performance and estimate the heat-sinking capability of the oil cooling system of engine in severe condition.