Abstract: It is necessary to calculate natural gas thermophysical property parameters in the water power and thermodynamic calculation of pipelines. The method of solving each physical property parameter of natural gas and solving process were introduced in detail. The compression factor of nitrogen gas was obtained by using Van der Waals equation, RKS equation, P-R equation and BWRS equation respectively. It is concluded from the comparison of the experiment data that as a two-parameter cubic equation, the P-R has more accuracy than that of the Van der Waals and the RKS equation, but slightly lower accuracy than that of BWRS equation. But P-R equation has less number of parameters and is easier to compute and determine parameters. Therefore, the P-R equation gets an extensive application in the area of thermophysical property calculation.

Key words: Natural gas, P-R equation, Application

摘要： 在天然气管道的水力、热力计算中需要进行热物性参数的计算，详细地介绍了用P-R方程求解天然气各物性参数的方法及其求解过程。分别采用范德瓦尔斯方程、RKS方程、P-R方程和BWRS方程求氮气的压缩因子，通过与已知实验数据比较表明P-R方程作为两参数立方型方程，计算气体物性参数精度高于范德瓦尔斯方程和RKS方程，略低于BWRS方程。P-R方程参数数目少，参数确定简洁，计算简单，可以在天然气物性计算领域广泛应用。

关键词: 天然气, P-R方程, 应用