Developing of vapor cooling system configuration for enhanced thermal performance of cryogenic hydrogen tank

Improving cryogenic insulation is critical for liquid-hydrogen (H۲) tanks because even small heat ingress can increase boil-off and accelerate self-pressurization. While multilayer insulation (MLI) used together with vapor-cooled shielding has been studied extensively, much of the literature evaluates preset designs under steady or simplified conditions, and fewer works treat shield design as an optimization problem under transient storage behavior. This work presents an optimization-focused assessment of a liquid-H۲ tank using MLI integrated with a vapor cooling system shield supplied by liquid-nitrogen boil-off. A coupled numerical approach is established by combining a layer-resolved insulation heat-transfer model with a dynamic multi-zone model that predicts tank self-pressurization. Under controlled boundary conditions, the shield location is optimized, reducing the heat flux into the tank from roughly ۰.۳۴ W/m_x۰۰۱۷_۸ to about ۰.۱۴ W/m_x۰۰۱۷_۸. The resulting configuration is then tested under time-varying storage conditions. Simulations indicate that the optimized insulation arrangement cuts the pressure rise by more than ۵۰% relative to operation without a vapor-cooled shield. Flow direction within the shield also matters: a top-down nitrogen flow performs better because it more effectively cools the vapor space, producing an approximate pressurization rate of ۲.۰ kPa/day at high fill levels, compared with about ۲.۷ kPa/day for bottom-up flow. In the optimized case, the daily evaporation loss falls below ۰.۰۵ kg/day. Overall, jointly optimizing shield placement and operating mode substantially improves thermal performance and storage stability, offering practical design guidance for advanced liquid-H۲ tank insulation.

کلیدواژه ها:

Cryogenic storage ، vapor cooling ، thermal performance ، H۲