工业结晶过程的多相流与粒数衡算的CFD耦合求解

考虑不同尺寸的晶体为不同的分散相，通过有限体积法差分不同尺寸组的晶体求解粒数衡算方程，建立了质量衡算与粒数衡算之间的联系，在考虑晶体成核和生长的条件下，建立了稳态结晶过程的粒数衡算方程与多相流方程的耦合求解方法，得到了工业结晶过程的计算流体力学模拟模型。使用商业软件ANSYS CFD，采用该模型对DTB 型工业结晶器中氯化钾-水体系的结晶过程进行了模拟，最终获得不同尺寸晶体的流场和固体含量的分布信息，从而实现结晶过程的仿真模拟。对部分模拟结果与实验值进行了比较，结果表明模拟结果与实验结果吻合较好。

Solution of population balance in multiphase flow field for industrial crystallization process

A method for solving the population balance equation coupled with multiphase flow field was developed for a steady crystallization process by considering nucleation rate and crystal growth rate. A simulation model with computational fluid dynamics (CFD) method was established for the industrial crystallization process. In this method, the different sizes of crystals were considered as the different dispersed phases. The relationship between mass balance and population balance was built by discretizing the population equation into different size groups with the finite volume method. By using this model in commercial software of ANSYS CFD, the crystallization process of potassium chloride in the draft tube baffle (DTB) crystallizer was simulated, then the flow fields and the volume fraction distributions of different dispersed phases were obtained. The simulation results were compared with experimental result. It was demonstrated that the modeling in this work can reasonably predict the flow fields and the volume fraction distributions of different dispersed phases in the industrial crystallization process.