Thermodynamic and economic assessment of a liquid nitrogen precooling dual-pressure Claude cycle for hydrogen liquefaction
Youan Ji
Hydrogen liquefaction remains one of the most energy-intensive steps in the hydrogen value chain. This study proposes a liquid-nitrogen-precooled dual-pressure Claude cycle and evaluates its performance using a detailed steady-state Aspen HYSYS model incorporating realistic turbomachinery characteristics, distributed ortho–para conversion, and temperature-dependent heat-exchanger constraints. Simulation results show that LN2 precooling provides approximately 40% of the total refrigeration duty,