乙烯热力学相平衡模型及相图研究

Study on thermodynamic phase equilibrium model and phase diagram of ethylene

研究了乙烯的热力学相平衡实验数据,给出了乙烯的气-固-液、固Ⅰ-固Ⅱ-液两个三相点温度和三相点压力以及临界温度和临界压力的推荐值;提出了系列乙烯热力学相平衡方程,包括冷凝曲线、熔融曲线Ⅰ、熔融曲线Ⅱ、熔融曲线Ⅰ+Ⅱ及升华曲线方程,拟合效果均优于文献方程;绘制了乙烯的热力学相图以及p-V和V-T相图;建立了乙烯的气-液相平衡的汽化焓方程,方程计算值的相对误差平均值为1.291%。

The experimental data of the thermodynamic phase equilibrium of ethylene was studied.The recommended values of temperature,pressure of ethylene for two three-phase points namely gas-solid-liquid,solid Ⅰ-solid Ⅱ-liquid respectively and the critical point temperature,pressure were given. A series of thermodynamic phase equilibrium equations of ethylene were proposed,including condensation curve,melting curve I,melting curve Ⅱ,melting curve Ⅰ + Ⅱ and sublimation curve equation. The fitting results were better than those of the literature equations. The thermodynamic phase diagram,p-V and V-T phase diagrams of ethylene were drawn. The evaporation enthalpy equation of vapor-liquid phase equilibrium of ethylene was established. The average relative error of the calculated value of the equation was 1.291%.