Toward Flexible Hydrogen Supply: Dynamic Simulation and Control of Mixed-Refrigerant-Precooled Liquefaction Plants

This study investigates the dynamic behavior of large-scale hydrogen liquefaction plants using mixed-refrigerant (MR) precooling to enhance operational flexibility for renewable energy integration. Hydrogen liquefaction is essential for hydrogen transport but remains energy-intensive. MR-precooled plants can significantly reduce energy consumption; yet, their dynamic performance and control strategies are underexplored. Dynamic simulation is crucial for capturing time-dependent responses to disturbances and designing robust control systems. This work develops the first dynamic simulation and control structure for an MR-precooled hydrogen liquefaction plant producing 100 tpd of liquid hydrogen (LH2). The model is validated against steady-state results and evaluated under variations in feed temperature, pressure, mass flow, and MR compressor power. Results show that the control strategy maintains the LH2 temperature at 22.5 K, restoring stability within 22 min to 96 min. These findings confirm the feasibility of dynamic control for MR-precooled liquefiers and provide a foundation for future validation with operational data.

Hydrogen liquefaction, Dynamic simulation, Control design, Ortho-para conversion, Equation of state, Mixed refrigerant precooling cycle

10.1016/j.ijhydene.2026.155036