惰性基弥散燃料芯块有效热导率数值仿真分析

Numerical Simulation Analysis of Effective Thermal Conductivity of Inert Matrix Dispersion Pellet

作为事故容错燃料的备选技术路线之一,惰性基弥散燃料芯块(IMDP,Inert Matrix Dispersion Pellet)的典型特征之一是具备高热导率。采用通用有限元软件ABAQUS,结合其二次开发功能,建立有限元计算模型,研究了IMDP燃料芯块有效热导率影响因素。研究表明,燃料颗粒在IMDP芯块基体中的分布形式以及燃料颗粒的形状对其有效热导率没有影响;惰性基体热导率相比燃料核心热导率对IMDP芯块有效热导率的影响更大;燃料颗粒—基体间热阻以及外部热解碳层—碳化硅层间热阻相比其他热阻对IMDP芯块有效热导率的影响更大;IMDP芯块的传热性能优于UO2芯块。

One typical characteristics of inert matrix dispersion pellet(IMDP)which was regarded as one of the alternative technical routes for accident tolerant fuel was high thermal conductivity.A finite element model was established by using the general finite element software ABAQUS combined with its two development functions,and the influence factors of the effective thermal conductivity of the IMDP pellet were studied.Results showed that the fuel particle distribution form in the IMDP matrix and fuel particle shape had no effect on the effective thermal conductivity of IMDP;Matrix thermal conductivity had more influence on effective thermal conductivity of IMDP compared to kernel;Fuel particle-matrix thermal barrier and OPy layer-SiC layer thermal barrier had more influence on the effective thermal conductivity of IMDP compared with other thermal barrier.The heat transfer performance of IMDP pellet is significantly better than UO2 pellet.