Numerical Investigation on Regenerative Heat-Driven Cryocoolers for Zero Boil-Off Storage of Liquid Hydrogen

Abstract

Aiming at the zero boil-off demand of liquid hydrogen storage tank, this paper uses SAGE software to design and simulate 300 W @ 20 K regenerative heat-driven cryocoolers, verifying the principle feasibility of duplex free-piston Stirling cryocooler and thermoacoustic heat-driven pulse tube cryocooler for the zero boil-off storage of liquid hydrogen. The results show that under the design conditions of mean pressure of 5 MPa, the operating frequency of 50 Hz, the heating temperature of 500°C, and ambient temperature of 30°C, the exergy efficiency of the duplex free-piston Stirling cryocooler can reach 19.4%, while the exergy efficiency of the thermoacoustic heat-driven pulse tube cryocooler is 14.3%. However, because a fixed-parameter harmonic oscillator is used to couple the engine and the cryocooler in the duplex free-piston Stirling cryocooler, it is difficult to achieve multi-condition matching, which makes it very sensitive to changes in operating parameters such as mean pressure and heating temperature. In contrast, the thermoacoustic heat-driven pulse tube cryocooler is completely free of moving parts and has excellent adaptability to the operating conditions. Therefore, the thermoacoustic heat-driven pulse tube cryocooler may be a promising solution in the application field of zero boil-off storage of liquid hydrogen.