As a clean energy carrier, hydrogen has attracted extensive international attention. Hydrogen liquefaction is the key solution of large-scale utilization of hydrogen energy. How to realize the high-efficiency and low-cost liquefaction of hydrogen is one of the key technologies that need to be solved urgently. In the current mainstream hydrogen liquefaction technology, the high-speed rotating turbine may have an adverse impact on the stable operation of the bearing. Therefore, the supersonic two-phase expander in liquid hydrogen temperature zone is innovatively employed for the first time to complete expansion refrigeration, condensation phase change, gas-liquid separation and pressure recovery in a compact space. It has the advantages of gas-liquid two-phase operation, direct liquefaction, easy high power, simple structure and low processing cost. In the hydrogen supersonic two-phase expander, Laval nozzle is the key component. The main research contents in this paper include: (1) Establish the design criteria of hydrogen Laval nozzles. (2) The design law of hydrogen Laval nozzles under different working conditions. (3) The cooling characteristics of hydrogen Laval nozzles under different operating conditions. This paper preliminarily investigates the liquefaction possibility of supersonic two-phase expansion refrigeration technology in liquid hydrogen temperature region, and supports the development of new hydrogen liquefaction technology. It has important strategic value for promoting the realization of carbon neutralization goal in clean energy industry.
Keywords Hydrogen liquefaction, Hydrogen supersonic two-phase expander, Hydrogen Laval nozzle