A novel insulation system based on active cooling without power input for liquid hydrogen storage

Hydrogen energy is a clean, efficient and renewable energy source. Compared with compressed gaseous hydrogen (GH(2)) storage and metal hydride storage, liquid hydrogen (LH2) storage has advantages of high energy density and storage efficiency. Excellent insulation system can effectively reduce heat leak into LH2 tank and evaporation loss. In comparison with vaporization heat (449 kJ/kg) of H-2, the sensible heat (from 20 K to 300 K, 3509 kJ/kg) and combustion heat (140 MJ/kg) are considerable. In this paper, thermoacoustic refrigerator shield (TRS) and self-evaporating vapor cooled shield (VCS) are introduced into different insulation materials to recover the sensible heat and combustion heat of discharged GH(2). The proposed insulation system is independent of external power supply and can realize efficient LH2 storage without H-2 emission into ambient, which can be used in skid-mounted LH2 storage tanks for remote areas. A self-built thermodynamic model, which has been verified by test results, is used to analyze the insulation performance with VCS and TRS quantitatively. For the proposed insulation system, the heat flux into tank with VCS decreased by 70.98% and TRS by 90.81%. The effects of hot boundary temperature, LH2 storage pressure and insulation material type on the insulation performance have been analyzed. (C) 2019 Elsevier Ltd. All rights reserved.