基于中空玻璃微珠和变密度多层绝热材料的液氢球罐复合隔热研究

The thermal insulation system of liquid hydrogen spherical tanks is the key to achieving low evaporation rate and economical storage. This paper uses“layer by layer”model to study the thermal insulation system composed of variable density multi-layer insulation (VDMLI) and hollow glass beads (HGB), design the support structure of the spherical tank enclosed space, and establish a prediction model for the heat leakage of the spherical tank. In this paper, daily evaporation rate of spherical tank under different insulation designs were compared. The effects of the vacuum degree of enclosed space, the total number of VDMLI layers and the layer density on the daily evaporation rate of the 25 m³ liquid spherical tank were analyzed. Thermal insulation system of the 2000 m³ liquid hydrogen spherical tank was designed based on construction quality, vacuuming difficulty, and cost of thermal insulation materials. The results show that the daily evaporation rate of a 2000 m³ liquid hydrogen spherical tank is 0.042%, which is 16% lower than that of a NASA spherical tank with the same volume.