在石油化学工业中,精馏、闪蒸、冷凝等是重要的单元操作,其理论基础是汽液相平衡。本文试图将热力学中的化学势与汽液平衡常数关联起来。对于多元系统,当发生相变时,每个组分在各相中的克分子数也要发生变化,系统的某些热力学函数值也随之变化。若选择温度、压力和克分子数作为自变量,Z表示某热力学函数,则 In the petrochemical industry, distillation, flash evaporation, condensation, etc. are important unit operations, the theoretical basis of which is the vapor-liquid phase equilibrium. This article attempts to correlate the chemical potential in thermodynamics with the vapor-liquid equilibrium constant. For multiple systems, when a phase change occurs, the number of moles of each component in each phase also changes and some of the system’s thermodynamic functions also change. If you choose temperature, pressure and mole number as independent variables, Z represents a thermodynamic function, then