The Role of Bayonet Tube on Heat and Mass Transfer Characteristics of Capillary Porous Wick Evaporator Based on AMTEC

摘要

An axial symmetric 2-D invariable temperature phase change interface model of capillary porous wick evaporator with bayonet tube for alkali metal thermal-to-electric converter (AMTEC) was established to simulate flow and heat transfer characteristics in capillary porous wick and liquid channel by solving the mass and heat transport controlling equations. The effects of length, radius and thermal resistance of the bayonet tube on the distributions of pressure, velocity and temperature in capillary porous wick and liquid channel were analyzed. The results show that the performance of evaporator can be improved by inserting a bayonet tube into the liquid channel, including better averaging function of temperature, reduction in the peak temperature on the inner surface of capillary porous wick, and better adaptability in working environment. However, bayonet tube parameters should be carefully chosen depending on specific working conditions.