Numerical analysis of heat transfer in peripheral air vaporizers used in cryogenic storage tanks

Abstract

In this study, the numerical study of fluid flow and heat transfer in peripheral air vaporizers used in cryogenic tanks are studied. The vaporizers under consideration include two simple and non-simple peripheral air vaporizers. The fluid enters the vaporizer (in the liquid phase) which is connected to a cryogenic reservoir and, after heat exchanging, is converted to the gas phase, and exits the vaporizer. Inside the two vaporizers, porous foam is used to fill the entire cross-section of the channel. The k-ε realizable model is used for simulation. The Reynolds numbers and the surface temperature vary in the ranges of 2400≤Re≤3000 and 280 K≤Ts≤310 K, respectively. The results show that in all cases, the use of non-simple vaporizer versus simple vaporizer has more satisfactory results in increasing heat transfer. Also, the performance of vaporizers at low surface temperatures leads to a further increase in heat transfer. The presence of porous foam can be considered as an auxiliary factor in increasing heat transfer. In maximum and minimum Reynolds numbers, the percentage increase in convective heat transfer coefficient for surface temperature changes from 300 to 310 K is equal to 15 % and 17 % for the simple vaporizer and 30% and 20% for the non-simple vaporizer, respectively.