Power generation system utilizing cold energy from liquid hydrogen: Integration with a liquid air storage system for peak load shaving

초록

Liquid hydrogen (LH2) can serve as a carrier for hydrogen and renewable energy by recovering the cold energy during LH2 regasification to generate electricity. However, the fluctuating nature of power demand throughout the day often does not align with hydrogen demand. To address this challenge, this study focuses on integrating liquid air energy storage with a power generation system based on LH2 regasification. Three configurations are proposed and compared: no-storage, partial-storage, and full-storage. In the no-storage system, power is generated using recuperated Brayton cycle and two organic Rankine cycles without energy storage. In contrast, the partial-storage system offers flexible operational modes. During peak times, cold energy is utilized for power generation, while it is diverted to store liquid air during off-peak times. In the full-storage system, produced energy is partially reserved throughout the day. Thus, compared to the partial-storage system, the full-storage system boasts a simplified configuration, eliminating the need for operational mode transitions. Furthermore, its larger liquid air storage capacity maximizes the difference in power production up to 4.53 MW between onand off-peak times. Consequently, despite its higher capital costs, the full-storage system demonstrates greater economic viability, especially when considering government subsidies.

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