Numerical analysis of the pressure behavior in cryogenic storage tanks under various insulation conditions

초록

Cryogenic liquefied storage systems require careful control of boil-off gas (BOG) to prevent hazardous pressure buildup caused by external heat ingress. In this study, a numerical model was developed and validated against experimental liquid nitrogen (LN2) data to investigate heat transfer and pressurization behavior in liquid hydrogen (LH2) storage tanks under various insulation and filling conditions. The Redlich-Kwong-Aungier equation and SST k-omega turbulence model with low-Re correction showed the best predictive performance. Using the validated framework, LH2 pressurization was analyzed under different vacuum levels and filling ratios. Results indicate that improved vacuum insulation significantly reduces heat ingress and suppresses BOG generation. Compared with LN2, LH2 exhibits faster convection and evaporation, leading to greater sensitivity to ullage volume. Additionally, ortho-para hydrogen conversion increases ullage pressure by up to 2.6% at high filling levels, highlighting its importance in LH2 storage system design and safety.

키워드