Influence of helium on process of thermal stratification and pressurization in cryogenic liquid oxygen tank

Cylindrical liquid oxygen tank is chosen to investigate the effect of helium on the process of thermal stratification development and pressurization. The initial tank pressure can be adjusted by changing proportions of gas helium and gas oxygen. The variations of thermal stratification and pressurization parameters are analyzed under conditions of equal and different initial tank pressure. It is found that gas helium enhances the natural convection intensity occurring between tank wall and liquid-vapor interface to strengthen evaporation phase change and mass diffusion. When the initial tank pressure keeps constant, both tank pressure increment and total phase change amount rise with increasing helium component. When the initial gas helium ranges from 0.0 kg to 0.563 kg, the tank pressure increment rises by 20.91%, the total phase change amount rises by 7.87 times. When the initial oxygen keeps constant, the tank pressure increment drops with the increasing initial helium quantity, and the total phase change amount tends oppositely. When the initial gas helium ranges from 0.0 kg to 0.2 kg, the tank pressure increment drops by 28.66%, and the total phase change amount rises by 4.3 times. © 2016, Editorial Office of Journal of Xi'an Jiaotong University. All right reserved.