Parameter study of the injection configuration in a zero boil-off hydrogen storage tank using orthogonal test design

This paper presents a steady-state numerical study of a zero boil-off liquid hydrogen storage tank in microgravity conditions. An injection configuration including a nozzle head and a guide tube is equipped to the ZBO tank. The colder liquid hydrogen injected from the nozzles and the guide tube cools down and mixes the main heated fluid inside the tank. The heated fluid then is driven from the outlet opening towards the external cooling system including a pump, cryocooler and heat exchanger to be cooled down and pumped into the injection configuration again to complete a working cycle. An axisymmetric model is employed to analyze the fluid flow and heat transfer inside the storage tank. Twenty five cases selected by the L25(56) orthogonal array with different geometry settings are performed to quantify the parametric study of the injection configuration. The influence of each parameter and the relatively optimal configuration for the injection are both investigated. The results show that the depth of the nozzle head has more influence than other parameters, the guide tube affects the fluid flow in the bottom region obviously, and properly structural parameters of the injection can improve the cooling and mixing performance of the ZBO tank.