Preliminary investigation of wickless-heat pipe as passive cooling system in emergency cooling tank

Abstract

To improve the thermal safety of a nuclear power plant, a wickless-heat pipe is proposed as a passive cooling system on an emergency cooling tank. Heat pipe will keep the water in the emergency cooling tank on normal operating temperature. The objective of this preliminary research is to investigate the characteristics of the wickless-heat pipe. RELAP/SCDAPSIM/MOD3.4 thermal-hydraulic code was used to analyze the characteristics of the wickless-heat pipe. The simulation results will be used as a basis for designing the future experimental investigations of the proposed wickless-heat pipe. The influence of the hot water temperature in the emergency cooling tank and the mass flow rate of coolant on the water jacket were investigated. The hot water temperature in the emergency cooling tank was varied, i.e. 60, 70, and 80°C. The mass flow rate of condenser coolant in the water jacket was varied, i.e. 2, 4, and 8 L/min. The initial pressure of the heat pipe was -74 cm Hg. De-mineralized water, which serves as heat pipe working fluid, was charged with filling ratio of 80%. The working fluid in the heat pipe can circulate naturally in stable condition if cooling water could absorb the latent heat in condenser. The simulation results showed that for constant hot water temperature, the increasing of condenser coolant volumetric flow rate will decrease the temperature of evaporator and condenser. While for constant condenser coolant volumetric flow rate, the increasing of hot water temperature will increase the temperature of evaporator and condenser.To improve the thermal safety of a nuclear power plant, a wickless-heat pipe is proposed as a passive cooling system on an emergency cooling tank. Heat pipe will keep the water in the emergency cooling tank on normal operating temperature. The objective of this preliminary research is to investigate the characteristics of the wickless-heat pipe. RELAP/SCDAPSIM/MOD3.4 thermal-hydraulic code was used to analyze the characteristics of the wickless-heat pipe. The simulation results will be used as a basis for designing the future experimental investigations of the proposed wickless-heat pipe. The influence of the hot water temperature in the emergency cooling tank and the mass flow rate of coolant on the water jacket were investigated. The hot water temperature in the emergency cooling tank was varied, i.e. 60, 70, and 80°C. The mass flow rate of condenser coolant in the water jacket was varied, i.e. 2, 4, and 8 L/min. The initial pressure of the heat pipe was -74 cm Hg. De-mineralized water, which serves as ...