泡核沸腾两相CFD模拟的参数敏感性分析与模型验证

摘要

预测偏离泡核沸腾(DNB)型的临界热流密度(CHF)是压水堆热工水力分析的重要内容.基于计算流体力学(CFD)方法预测CHF需要准确预测空泡份额在截面上(尤其是壁面附近)的分布.本文使用商用CFD程序STAR-CCM+对泡核沸腾状态下DEBORA竖直上升流均匀加热圆管实验进行模拟.经过敏感性分析,找出对空泡份额、气体速度、液体温度和气泡直径四个物理量的径向分布以及轴向壁面温度分布有显著影响的模型参数.基于一组实验数据,通过调整关键模型参数重新标定了相间作用模型,并将标定过的计算模型应用到其他工况验证其适用性,得到了较好的结果.本研究为后续将两相CFD计算应用于DNB型CHF的预测打下了基础.%The prediction of critical heat flux (CHF) of departure from nucleate boiling (DNB) type is significant in the thermal-hydraulic analysis of pressurized water reactor (PWR). It is necessary to predict the distribution of void fraction over the section plane (especially near the wall) exactly before predicting CHF based on computational fluid dynamics (CFD) methods. In this study, the commercial CFD software STAR-CCM+is used to simulate the DEBORA test. By sensitivity analysis, model parameters, which have great influence on the radial distribution of void fraction, gas velocity, liquid temperature and bubble diameter, and on the axial distribution of wall temperature, are found out. The interfacial interaction model is calibrated by adjusting the key model parameters based on one set of experimental data. Then the calibrated calculation models are used in other working conditions to verify the applicability, and good results are received. This study lays the foundation for the application of two-phase CFD simulation in predicting CHF of DNB type subsequently.