基于CFD方法的棒束通道内临界热流密度预测

Prediction of Critical Heat Flux in Rod Bundle Based on CFD Methodology

为研究棒束通道内临界热流密度现象,采用基于对气、液两相分别建立基本守恒方程的欧拉两流体六方程模型和改进的壁面热流密度分配模型,利用CFD商用软件FLUENT 14.5对捷克大型水介质实验回路上开展的临界热流密度(CHF)实验进行数值模拟。通过计算获得CHF发生前、后计算域内重要热工水力参数的分布及CHF发生值,将CFD计算获得的CHF与实验测得值进行对比,结果表明,大多数工况的偏差在±30%以内,证明了欧拉两流体模型结合改进的壁面热流密度分配模型对CHF预测的准确性。本研究可为复杂结构的CHF预测提供依据。

To evaluate the critical heat flux（CHF）,the Eulerian two-fluid model coupled with improved RPI（Rensselaer Polytechnic Institute）wall boiling model was employed to investigate the CHF phenomena in rod bundles by using FLUENT 14.5 code.By comparison between the predicted CHF and measured one in large water loop experiment in Czech,it is found that most deviations are in the region of less than±30%.The results prove that Eulerian two-fluid model coupled with improved RPI wall boiling model is qualified to predict CHF accurately.The work in the paper can provide reference for predicting CHF in complicated geometry by CFD methodology.