比热2好学的热力学.pdf

重力场中真实气体内能与状态方程的关系 缪波 （比亚迪股份有限公司 518116） 摘 要：真实气体内能包括动能和势能。假定动能只与温度有关，与体 积和密度无关。在重场中，真实气体服从静力平衡和对流平衡。这两个 方程包含重力、分子势能和状态方程。将这两个方程组合起来消除重力， 得到了状态方程与势能之间的关系。根据这种关系，本文从状态方程计 算了HFC125 的比热，R143a，、HFC227ea 声速的维里系数。三个结果与 实验相符。 关键词：真实气体，静力平衡，对流平衡，内能、状态方程，R143a，HFC227ea, HFC125 The relation between the internal energy and the equation of state of real gas in the gravitational field Bo Miao (Byd Company Limited, Ltd. 518116) Abstract The internal energy of real gas includes kinetic energy and potential energy. It is assumed that kinetic energy is only concerned with temperature and is independent of volume and density. In gravitational field, real gas obey static equilibrium and convection balance. The two equations contain gravity, molecular potential energy and equation of state. The two equations are combined to remove gravity, and the relationship between the equation of state and potential energy is obtained. According to the relation, this paper calculates the specific heat of HFC125, sound velocity virial coefficients of R143a, HFC227ea from the state equation. The three results are in accordance with the experiment. Keywords: real gas, static equilibrium, convection equilibrium, internal energy, equation of state, free energy, R143a, HFC-227ea, HFC125 1 引 言 真实气体的内能主要包括动能和势能，假设气体的动能与气体的密度（或者体积无关）， 表示为: x Ek RT (0.1) 2 真实气体的势能是密度的函数，1mol气体的势能为  ，一个分子具有的势能为： E E  p p 1