A novel hydrogen liquefaction model: numerical study of supersonic condensation and structural optimization for multi-state hydrogen for enhanced transportation

Abstract

Hydrogen, as a clean and sustainable energy carrier, has attracted increasing attention for large-scale storage and long-distance transportation, primarily through liquefaction. However, conventional hydrogen liquefaction systems are often complex, bulky, and energy-intensive, which constrains their widespread deployment and economic feasibility. To address these challenges, this study develops a novel numerical modeling framework that systematically simulates the multi-state non-equilibrium condensation process of hydrogen during supersonic expansion liquefaction. The proposed blend linear numerical model captures the intricate coupling of non-equilibrium phase transitions across supercritical, near-critical, and subcritical hydrogen states. Results indicate that elevated pressure enhances nucleation, reduces supercooling, and significantly promotes phase change, with a peak liquid hydrogen production of 30.67 % observed near critical conditions. To better evaluate system performance, flow loss coefficients and a comprehensive liquid hydrogen yield index are introduced to provide a more rigorous quantification of irreversible losses. Furthermore, by optimizing nozzle inlet geometries, the conclusions show that the WTC nozzle exhibits superior performance in supercritical state, while the BSC nozzle optimizes liquid yield under near- and subcritical conditions. These findings provide critical insights to enhance the economic viability of the hydrogen energy sector, advance the development of hydrogen storage and transportation technologies, and contribute to the realization of a low-carbon economy and advanced cryogenic refrigeration systems.