Analysis of Heat Transfer Performance Impact for Passive Containment Air-Cooling System Radiation Plates

In addition to convective heat transfer, radiation heat transfer constitutes a significant component of the thermal performance of Passive Containment Air-Cooling System (PAS). The installation of radiation plates within the PAS flow channel enhances the convective heat transfer area between the wall and the air, an effect that should not be overlooked. ANSYS Fluent was employed to investigate how the placement and quantity of radiation plates influence the heat transfer efficiency of PAS. The computational results indicate that radiation plates can substantially enhance the thermal performance of PAS. Specifically, when a radiation plate is positioned 0.9 m from the inner wall of the concrete shell, an improvement in PAS heat transfer power by as much as 34.4% can be achieved. However, it was observed that increasing the number of radiation plates has a minimal impact on overall performance; thus, utilizing multiple plates does not further augment the PAS heat transfer capability. Nonetheless, incorporating several radiation plates may contribute to lowering the temperature of the concrete shell. Based on this research, it can be concluded that strategically arranging radiation plates significantly improves the PAS heat transfer capacity. While multiple radiation plates do not provide additional enhancements to heat transfer efficiency under normal conditions, they remain a viable option for mitigating concrete shell temperatures during accident scenarios.