[3J13-15] Density Stratification and Natural Convection

[3J14] Investigation on heat transfer characteristics of reactor cavity cooling system for high temperature gas-cooled reactor

*Seisuke Hosomi¹, Shuhei Yamaguchi¹, Tomoyasu Akashi¹, Tatsuya Matsumoto¹, Wei Liu¹, Koji Morita¹, Kuniyoshi Takamatsu² (1. Kyushu Univ., 2. JAEA)

Keywords:High temperature gas-cooled reactor, Reactor cavity cooling system, Radiative heat transfer, Scaled model, Heat transfer experiment

Reactor Cavity Cooling System (RCCS) is a new cooling concept with passive safety features. It is being considered for use in the next generation High-Temperature Gas - Cooled Reactor. To contribute to the evaluation of the thermal feasibility of the RCCS, this research aims to understand the heat transfer characteristics of natural convection and radiation, by conducting a heat transfer experiment using a scaled down model test facility. Experiments were performed with the emissivity of the heater surface and the cooling surfaces as parameters. Wall temperature and heat flux data was obtained in a series of cases when the cooling contribution of radiative heat transfer was changed. Regarding the evaluation of radiation heat transfer, we adopted the Monte Carlo method so that the directional reflection can also be evaluated. The applicability of the Monte Carlo method was confirmed by the comparison with the conventional shape factor method.