含较多参数的气体状态方程如Beattie-Bridgeman方程等虽然准确度较高,但其参数必须依该给定物质P-V-T关系的实验值求得,且计算冗繁,因而限制了它们的应用.仅含两个参数的Redlich-Kwong状态方程(以下简称R-K方程)的准确度较其它含两个或某些含三个参数的状态方程为好,这说明气体状态方程中函数的形式是很关键的.R-K方程实质上是一经验方程,具有下列形式: Gas-state equations with more parameters, such as the Beattie-Bridgeman equation, have higher accuracy but their parameters must be determined from experimental values ​​for the PVT relationship of the given substance and their calculation is cumbersome, thus limiting their application. The accuracy of the two-parameter Redlich-Kwong equation of state (hereinafter referred to as the RK equation) is better than the other two or some of the three-equation equations of state, indicating that the form of the function in the gas equation of state is crucial. The RK equation is essentially an empirical equation with the following form: