换热器传热过程的(火用)分析

本文以热力学第二定律为理论依据，对换热器的熵损失，熵效率进行了分析。导出了同时考虑热熵损失和流阻熵损失时的熵损失、熵效率的计算公式，结果表明，考虑了流阻熵损失后，换热器的熵损失、熵效率可能出现极值点。当热负荷一定时，换热器的管径，冷热流体的流速应合理匹配使换热器的熵尽可能地得到利用。

Exergy Analysis of Heat-Exchange Process of Heat-Exchanger

Through the exergy analysis of heat-exchange process, the author in this paper has derived the calculation formilae of exergy low(ΔE) & exergy efficiency under the circumstances of cosidering heat exergy low and flow exergy low simultaneoraly. the results show that there is a possible esistence of the limit point ofΔE. when load of heat-exchanger (Q)is constant. To make use of exergy of heat-exchanger as much as possible，the diameter of heat-exchanger and the flow rate of cold & heat fluid should be appropriately matched.