改进SRK方程提高正构烷烃饱和蒸气压和液体体积预测精度

<正>引言 在化学工程和油藏工程的相平衡和其他热力学性质计算中,两参数立方型SRK方程应用最为广泛。然而,在某些情况下由SRK方程预测的饱和蒸气压出预测的液体体积偏差较大,无法满足工程计算的需要,必须改进方程,提高其预测精度。1 饱和蒸气压的改进 SRK方程可以写为 p=RT/（V-b）-(a(T)）/V(V+b) （1）

MODIFIED SRK EQUATION OF STATE TO IMPROVE PREDICTION OF SATURATED VAPOR PRESSURES AND SATURATED VOLUMES OF ALKANES

SRK equation of state(EOS) is modified to improve the prediction of vapor pressures and saturated liquid volumes of alkanes (C1 -C20). The new generalized correlations for calculating the parameters n and m in the α ( T) function as well as C and S used for volume translation method are proposed. The modified SRK EOS is applicable for calculating the vapor pressures and saturated volumes from friple point to critical point, and it has been compared with SRK, PR, TVDW, PT, SW and Lee - Kesler empirical correlation.