Cryogenic cooling and fuel cell hybrid system for HTS maglev trains Employing liquid hydrogen

Abstract

High-Temperature Superconducting (HTS) maglev trains hold great promise for transforming transportation, achieving speeds beyond 1000 km/h with superior energy efficiency. However, maintaining the superconducting state requires cryogenic cooling, which presents challenges under constrained space, weight, and power conditions. To overcome these limitations, this study proposes a hybrid system combining a liquid hydrogen (LH₂) thermal battery and a fuel cell. LH₂, with its low boiling point and high latent heat, serves as an effective coolant for HTS magnets, while the evaporated hydrogen is utilized in a fuel cell to produce onboard power, enhancing the system’s overall efficiency. To validate the proposed concept, a thermal network model was developed incorporating sections for HTS magnets, an LH₂ thermal battery, and a fuel cell. The HTS magnet section models the thermal resistance variation due to LH₂ level reduction and considers heat influx from conduction, radiation, and AC losses. The LH₂ thermal battery simulates hydrogen evaporation caused by heat transfer, with the vaporized hydrogen directed to the fuel cell for power generation. Simulations using MATLAB Simscape analyzed the dynamic thermal behavior of the system under operational scenarios. The study demonstrates the capability of the LH₂ thermal battery to maintain thermal stability for HTS magnets while leveraging evaporated hydrogen for onboard power generation. This integrated approach offers a foundation for optimizing cryogenic cooling and energy management, providing key insights for the development of next-generation HTS maglev train systems.