Investigation On Zero Boil-off System Of Liquid Hydrogen Based On Pulse Tube Cooler

Hydrogen is a promising energy in the 21^st century. It is a clean energy carrier made from diverse resources, and has high energy content per unit weight. Hydrogen in the long-term will simultaneously reduce dependence on fossil fuels and emissions of greenhouse gases and criteria pollutants.Liquid hydrogen, as one of most used storage methods, has wide applications. Focusing on the heat loss of liquid hydrogen storage, recent developments of zero boil-off (ZBO) storage system were reviewed in two aspects, such as passive insulation technology and active technology by using cryocoolers.By using the liquid hydrogen storage model, the storage time of liquid hydrogen and average boil-off rate per day were predicted in both of the situations: with and without a pulse tube cryocooler. According to the ZBO storage methods of other cryogens, a system of centralized re-condensation of liquid hydrogen using a pulse tube cryocooler for a large container was proposed. Two design methods were suggested and compared, such as liquid hydrogen circumfluence system and liquid hydrogen recycling system. In order to satisfy the requirement of ZBO storage of liquid hydrogen, a G-M type single-stage pulse tube cryocooler was designed and built up. In the preliminary experiment, a lowest no-load refrigeration temperature of 11.3 K was obtained. The PTC can supply 20 W at 21 K with actual input power of 7.5 kW, which can meet the requirement.