Experimental study on thermal stratification in water tank and heat transfer characteristics of condenser in water-cooled passive residual heat removal system of molten salt reactor

摘要

Based on the residual heat removal system of molten salt reactor (MSR) in Oak Ridge National Laboratory, a set of water-cooled passive residual heat removal system (PRHRS) applied to 2 MW thorium based MSR is designed and built. During the preheating of the water-cooled PRHRS, the open and closed natural circulation are started respectively. Then, the thermal stratification effect in the water tank of the system and the overall heat transfer characteristics of the condenser are studied under different start-up modes, and the temperature distribution and heat transfer characteristics in the water tank under transient conditions are obtained. The results show that under open startup mode, the development degree of thermal stratification in water tank is hardly affected by the heating power, completely different from that in closed startup mode. And development law and overall heat transfer characteristics of condenser differed under both two startup mode. The results and characteristics could provide applicable and effective references for the actual operation and safety analysis of the PRHRS in the later commercial MSR.