Development of a full-scale MATCH model in heat transfer performance simulation of RPV insulation structure with experimental validation

In a core meltdown accident, the reactor pressure vessel (RPV) insulation plays a significant role in the flooding process of the reactor cavity. The research on the function role of RPV insulation has attracted lots of attention whereas there are relatively few studies on heat transfer characteristics. Besides, the majority of previous studies on RPV insulation adopted a down-scaling or partial model instead of the entire model to decrease computational complexity. In this paper, a mesh assembly method is proposed to generate block-structured meshes and the heat transfer characteristics of the RPV insulation is carried out. Then a partial validation model has been verified against the experiments results. In addition, the effects of the air supply temperature, flow rate, and insulation installation gap on the overall model heat transfer performance of RPV insulation are investigated. The results demonstrate that the mean temperature of the insulation's outer wall (42.92 degrees C), the local temperature of the concrete (73.85 degrees C), and the heat flux of the insulation's outer wall (93.48 W & sdot;m-2) are less than their limit values of 60 degrees C, 95 degrees C, and 235 W & sdot;m-2, respectively. And the heat leakage from the supports accounts for over 90% of the total heat dissipation.