超音速冷凝分离过程的自发成核影响因素分析

Analysis of Influencing Parameter on Spontaneous Nucleation During Supersonic Condensing Separation

建立了两相双组分超音速冷凝流动三维湍流模型,对含湿气体在超音速冷凝流动中的自发成核进行预测。采用两相欧拉-欧拉控制方程组描述气液两相流动,引入经典成核理论模拟水蒸气的自发成核。模型计算结果与实验值吻合较好。以水蒸气和甲烷的混合气体为介质,模拟研究了天然气在超音速冷凝流动中的自发成核,得出了天然气超音速冷凝分离装置的结构参数和操作参数对自发成核的开始位置、强度、成核区轴向长度和最小临界成核半径的影响规律。研究结果表明,对超音速冷凝分离装置的分离性能有显著影响的操作参数足初始水蒸气分压和初始温度,所有的结构参数都影响分离性能;所有的操作参数都对能耗有显著影响,而结构参数中只有旋流发生器高度对能耗有影响。

Spontaneous nucleation of condensable gas components, a major way of droplet formation in technology of supersonic condensing separation, greatly affects the separation performance and energy consumption of supersonic condensing separator. A two-phase bicomponent threedimensional turbulent model was presented to predict spontaneous nucleation of humid gas in supersonic flow. The two-phase flow described by Eulerian-Eulerian multiphase equations was adopted and spontaneous nucleation was simulated according to classical nucleation theory. The results obtained by proposed model show good agreement with experimental data. Taking humid methane as separation object and using this model, spontaneous nucleation in supersonic condensing separation of natural gas was studied. Effects of structural and operational parameters on starting location of spontaneous nucleation, intensity, longitudinal length of nucleation zone and minimum critical nucleation radius of spontaneous nucleation were investigated. The results indicated that among operational parameters, initial partial pressure of water vapor and initial temperature show remarkable effect on separation performance; and among structural parameters height of swirling generator is most important to energy consumption of equipment.