基于Soave-Redlich-Kwong气体物态方程的CH4焓、熵图数值计算及关联应用程序开发

Numerical calculations of enthalpy and entropy chart of CH4 gas based on Soave-Redlich-Kwong gas state equation and related application program development

运用Soave-Redlich-Kwong真实气体物态方程(SRK方程),结合状态函数焓和熵的全微分形式,使用Mathematica软件以数值方法计算得到了CH4(甲烷)气体的焓图和熵图.基于Mathematica软件具有的交互性和即时计算功能,借助零压强条件下的CH4气体热容量测量数据,开发出CH4在2个任意热力学状态间的焓差和熵差即时计算及查询程序.考虑到真实气体物态方程的误差,参考实验测量得到的焓、熵图数据,在程序中加入线性修正代码,对理论计算值进行修正.经过对随机生成的热力学状态间焓、熵差的程序计算值与实验值进行比较,发现所开发程序具有较好的准确度.

Using the Redlich-Kwong-Soave real gas equation of state(SRK equation), combined with the full differential forms of enthalpy and entropy, the charts of enthalpy and entropy of CH4 gas are calculated numerically using Mathematica software. Based on the interactivity and update function of Mathematica, with experimental heat capacity of CH4 gas under the zero-pressure condition, instant calculation and query program for enthalpy and entropy differences of CH4 between two arbitrary thermodynamics states are developed. Taking into account the error of the real gas state equation, referencing experimentally measured data of enthalpy and entropy charts, a linear correction code is added to the program to correct the theoretical calculation values. For randomly generated thermodynamics states, the program calculated results of enthalpy and entropy differences are compared with the experimental results. It is found that the developed program has comparatively high accuracy.