利用天然气气体临界参数计算压缩因子的简便算法

A simple algorithm to calculate compression factor by using critical parameters of natural gas

AGA8-92DC方程的计算方法,对常规天然气的压缩因子计算十分精确,但是在运算过程中,引入大量的中间变量、定位参数以及交互参数,计算过程比较繁琐。该文利用立方体状态方程式—PR方程,基于混合气体的临界状态,提出新的拟合公式来代替原本在PR方程中使用的二元交互作用参数,以达到简化计算过程的目的。并在计算酸性天然气压缩因子计算结果方面,与原AGA8-92DC方程相比,使用该简便算法,其计算结果更接近实验室测得的压缩因子。

AGA8-92 DC equation,which is very accurate for the calculation of conventional natural gas compressibility factor,but in the calculation process,a large number of intermediate variables,positioning parameters and interactive parameters are introduced,which makes the calculation process more complicated.Based on the critical state of mixed gas,a new fitting formula is proposed to replace the binary interaction parameters used in PR equation,so as to simplify the calculation process.Compared with the original PR equation and AGA8-92 DC equation,the calculation results of conventional natural gas compressibility factor and acid natural gas compressibility factor are more close to the laboratory measured compressibility factor.