基于CPFD方法的UO_(2)氢氟化流化床反应器数值模拟

CPFD Simulation of UO_(2)Hydrofluorination in Fluidized Bed Reactor

深入认识和掌握流化床内气固两相流动规律和反应机理对于UO_(2)氢氟化流化床的工程应用具有重要意义。传统的实验方法研究成本高、周期长,因此,数值模拟方法成为更多科研设计人员的选择。基于计算颗粒流体力学(CPFD)建立了UO_(2)氢氟化二级流化床的数学模型,筛选了适用于UO_(2)-UF 4体系的曳力模型,推导出了氢氟化反应的阿伦尼乌斯方程。在该模型的基础上,研究了HF进气方式、操作气速、固体颗粒直径对流化质量的影响。仿真结果表明,目前设计参数合理,氢氟化二级流化床可形成良好的温度分布,转化率接近生产要求。基于CPFD方法建立的氢氟化数学模型可较准确模拟流化床反应器的运行情况,可为流化床反应器的放大设计和运行调试提供参考依据。

It is of key importance to understand and master the law of gas-solid two-phase flow and reaction mechanism in UO_(2)hydrofluorination second stage fluidized-bed for its engineering application.The traditional experimental method has high cost and long periodic,so the numerical simulation method has become the choice of more researchers and designers.Based on the CPFD method,the mathematical model of the UO_(2)hydrofluorination fluidized-bed was established,the drag model applicable to the UO_(2)-UF 4 system was screened out,and the Arrhenius equation for the hydrofluorination reaction was deduced.According to the model,researches on the influence of the HF inlet,the operating gas velocity,and the solid diameter on fluidization were conducted.The simulation results show that the current design parameters are reasonable,and UO_(2)hydrofluorination second stage fluidized-bed can form a good temperature gradient distribution and the percent conversion is close to the production requirement.The mathematical model of UO_(2)hydrofluorination fluidized-bed based on CPFD can accurately simulate the operation of fluidized-bed and provide useful references for enlarged design and operation.