Integrated thermal modeling and parametric study of liquid hydrogen storage tanks: Effects of insulation design and operating conditions

In this study, an integrated thermal model for a liquid hydrogen storage tank was developed, which consists of three major parts: tank design, thermal network, and dynamic behavior of hydrogen. Based on the user's design and operating condition requirements, the model calculates the appropriate design parameters and builds a thermal network to compute heat transfer rates across the tank components of the inner and outer shells, insulation, suspensions, fill/drain pipe, vent line, vaporizer, and level sensor. It also simulates the time-dependent behavior of hydrogen in the tank to compute temperature, pressure variation, and predict dormancy and boil-off rate (BOR). Using this integrated model, a parametric study was done on 41 cases of 500 L liquid hydrogen storage tanks with different insulation parameters and operating conditions. The important findings from the parametric analysis are as follows. Firstly, there is an optimum number of layers for the multi-layer insulation (MLI), which is identified as 40 in this study. Secondly, silk net spacers exhibit good insulation performance, achieving 1.01 W/m2. Lastly, repeating the venting valve opening and closing within a certain pressure range greatly minimizes immediate hydrogen loss during venting, reducing the 6-h boil-off mass by 92.9 %.