A high-efficiency liquid hydrogen storage system cooled by a fuel-cell-driven refrigerator for hydrogen combustion heat recovery

•A fuel-cell-driven refrigerator was used to recover hydrogen combustion heat.•The efficiency is increased by 80.3–83.2% compared with traditional system.•The loss rate is reduced by 55.7% compared with traditional zero-boil-off system.•The efficiency is further improved by 8.1% by recovering the sensible heat. Effective thermal insulation technology is served as the key to liquid hydrogen storage. Existing studies have mainly been shedding light on the performance optimization of the passive thermal insulation systems or the direct introduction of refrigerators to achieve zero-boil-off storage. However, considering the immense combustion heat that is taken away by gaseous hydrogen discharged from the passive thermal insulation system, and the additional electric power required to be introduced in driving the refrigerator under the current zero-boil-off system, this paper is intended to propose a novel liquid hydrogen storage system that is cooled by a fuel-cell-driven refrigerator for hydrogen combustion heat recovery. In an effort to reduce the heat leakage, the combustion heat is recovered and converted into electricity, which can then be used to drive the refrigerator in cooling the passive insulation material. In this paper, a thermodynamic calculation model composite of the fuel cell, refrigerator, and passive thermal insulation system was established and verified. According to the results, at a fuel cell efficiency of 50%, the insulation efficiency of the proposed system is improved by up to 80.3% compared with the traditional multi-layer insulation system. Besides, the effects of fuel cell efficiency, refrigerator efficiency, cold shield position, storage pressure, boundary temperature, and system vacuum on the insulation performance were also analyzed.