Three-dimensional numerical investigation of heat transfer process in the reactor cavity of HTR-10

The 10 MW High Temperature Gas-cooled Test Reactor (HTR-10) is the first Modular High Temperature Gas-cooled Reactor (MHTGR) in China. The heat transfer process in the reactor cavity of HTR-10, which was very important for the decay heat to be removed, was investigated with a three-dimensional numerical model in this study. The temperature distributions of air, water cooled panel and water in five experimental conditions were analyzed. The heat transfer rates on the reactor pressure vessel (RPV) wall, front and back wall of the water cooled panel, and outer wall of the water cooled pipe were calculated. Besides, the percentages of radiation heat transfer rate on these walls were given, and the variations of them with the RPV temperature rising were also analyzed. The results show that radiation between the RPV and the steel sheet, heat conduction between the steel sheet and the water cooled pipe, and convection between the water cooled pipe and the water form the main way that the heat is removed, especially when the RPV temperature is high. The maximum temperature of air occurs on the top of the RPV. In addition, as the RPV temperature rises, the heat transfer rates and the percentages of radiation all increase.