Abstract
A cooling system using a cryocooler and boil-off gas was proposed for cryogenic propellant storage on the lunar surface. The cryogenic tank was covered with an advanced non-interlayer-contact multi-layer-insulation and coolant from the cryocooler and boil-off gas flow in the layers to remove the heat load. The proposed system included optimization factors for fluid tubes location, cryocooler temperature, and flow rate. A simple uniformtemperature thermal model was developed to optimize boil-off rates and system weights, and the results revealed a Pareto front. A three-dimensional model was developed to discuss the effect of temperature nonuniformity. Finally, the proposed concept was compared to other candidates. The results showed that the proposed system offered a well-balanced system in terms of boil-off rate, system mass, and electric power consumption, which drastically reduced the boil-off rate when compared to only multi-layer insulations, which reduced the weight and power consumptions as compared to zero-boil-off systems.
NSTL
Elsevier