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Description
Ortho-para hydrogen conversion is a pivotal step in the hydrogen liquefaction process. This study introduces a novel single-fluid conduction-type GM cryocooler heat exchanger designed specifically for hydrogen liquefaction, with its performance enhanced through systematic optimization. The heat exchanger utilizes oxygen-free copper as the conductive material and incorporates ortho-para hydrogen conversion catalysts, enabling simultaneous conversion and liquefaction of hydrogen during cooling. To streamline the design and improve overall system efficiency, a parameter adjustment strategy based on fluid dynamics and heat transfer optimization is proposed. An optimization model is developed to maximize the heat exchanger’s volumetric performance, thus improving heat transfer efficiency and the hydrogen liquefaction process. Using the NLopt-based COBYLA algorithm, key design parameters, such as channel diameter, the number of flow channels, and the heat exchanger length, are optimized. Numerical simulations reveal the coupled process of ortho-para hydrogen conversion and convective heat transfer within the temperature range of 20 K to 81 K, offering an efficient and practical solution for hydrogen liquefaction and energy storage systems.
Keywords；Hydrogen liquefaction； GM cryocooler (Gifford-McMahon cryocooler)； Ortho-para hydrogen conversion； Heat exchanger design； Optimized design
