Abstract: The crude and wax liquid/solid phase equilibrium calculation was performed with the liquid phase described by EOS and activity coefficient approach and the solid phase described by solution theory respectively. The effects of PR, SRK equations and activity coefficient approach describing liquid phase characteristics on liquid/solid phase equilibrium calculation were compared. The analysis on study case show that the calculation results are similar if the liquid phase is described by PR and SRK equations, and the calculation results are also similar if liquid and solid phases are both described by activity coefficient approach. The above results confirm that for the crude/wax deposition phase equilibrium calculation, EOS or activity coefficient approach can be used to describe liquid phase characteristics, which affect the phase equilibrium calculation a little.

Key words: Crude oil, Wax deposition, Equations of state, Activity coefficient approach, Liquid and solid phase equilibrium

摘要： 分别采用状态方程和活度模型描述液相，采用溶液理论描述固相，对液固两相平衡进行了计算。比较了ＰＲ和ＳＲＫ状态方程以及活度模型描述液相特性时对液固平衡计算结果的影响。通过算例分析可知，采用ＰＲ和ＳＲＫ状态方程描述液相时相平衡计算结果差别不大，液相和固相都采用活度模型时计算结果也很相近。上述结果表明，对于计算原油中固相沉积相平衡，可以采用状态方程或者活度模型描述液相的特性，两者对计算结果的影响不大。

关键词: 原油 , 蜡沉积 , 状态方程 , 活度模型 , 液固平衡