用热力学第一及第二定律分析由对流与辐射共同构成的复合换热过程,从而建立起能定量评价其流动与换热性能的(火用)损失率方程,并用它分析空气流过平板的层流流动换热过程.结果表明,辐射换热的存在使换热过程的(火用)损失率减小,且随着换热平均温度的升高拥损失率减小的程度更为显著. The first and second laws of thermodynamics are used to analyze the composite heat transfer process composed of convection and radiation so as to establish the exergy loss rate equation that can quantitatively evaluate its flow and heat transfer performance and use it to analyze the air flow through the plate The results show that the exergy loss rate of the heat transfer process decreases with the existence of radiative heat transfer, and the degree of loss reduction decreases with the increase of the average heat transfer temperature.