空气管流两种典型工况的热力学性能分析

Thermodynamic Performance of Air Flow in Tube under two Conditons

在壁面等热流和壁面等温度两种工况空气管流过程的流体力学及传热学研究基础上进行了热力学性能比较,指出两种工况下空气管流过程的热力学性能差别,同时提出了性能比较依据——热力学能量特性准则方程式。分析比较结果表明,壁面等热流工况空气管流过程的能量综合利用效果较优越,并且存在较小的热力学不完善度,还对各项主要影响因素进行了较深入的分析探讨。

This paper studied the thermodynamic performance of air flow in tube on the basis of aerodynamics and heat transfer,and presented a concept, the available energy loss dimensionless factor , and gave its dimensionless equation to analyse the irre-versibility and available energy loss degree of air flow in tube. The equation contains two parts of heat transfer and flow. In order to compare the thermodynamic performance of air flow in tube under both working conditions of equal wall heat flux and temperature, both dimensionless equations were established as comparing criteria to evaluate the difference of the thermodynamic performance. Through the comparision and anaylsis the conclusion was taken that the available energy loss of air flow in tube on the condition of equal wall heat flux is lower and has a less irreversibility,than that on the condition of e-qual wall temperature. The paper also analysed the effect of various parameters, fllow-ing,constructure of the tube,heat transfer and so on.