节流过程中的致冷与致热分析

在真实气体物态方程中，压强和体积的修正项导致了节流过程的致冷和致热．通过对范德瓦耳斯方程的分解，从理论上得到了压强的修正项导致气体致冷，体积的修正项导致气体致热的结论．结合节流过程，从实验角度进一步分析了致冷和致热的物理原因．最后，从真实气体分子相互作用势的角度出发，探讨了分子间的吸引作用导致气体致冷的机理．

Cooling and heating analysis for the Joule-Thomson process

Due to the terms of pressure and volume corrections, the real gas occurs heating or cooling during the Joule-Thomson process. The rigorous derivation is carried out by separating the van der Waals' equation, and the following results are obtained: pressure correcting coefficient leads to cooling and volume correcting coefficient leads to heating. Furthermore,the physical reasons of cooling and heating are analyzed on the basis of the Joule-Thomson experiment. Finally, the mechanism of the cooling by the attraction between two real gas molecules is investigated in terms of interaction potential.