Design and thermodynamic analysis of an advanced liquid air energy storage system coupled with LNG cold energy, ORCs and natural resources

Liquid air energy storage (LAES) is a kind of cryogenic energy storage technology that offers the advantages of relatively sizeable volumetric energy density and ease of storage, which will have good application prospects for power management systems in the future. An advanced LAES system coupled with LNG cold energy, ORCs and natural resources is proposed in this paper, in which external energy sources are simultaneously utilized in both the energy storage and energy release process to enhance the system performance. The cold storage subsystem is designed to recover LNG cold energy during peak hours for flexible operation. Organic Rankine cycles are established in both LNG regasification process and energy release process, thus entirely using cold energy to improve energy efficiency. Multi-parameter genetic algorithm is adopted to achieve optimal performance. It turns out that the proposed LAES system has high electrical round-trip efficiency and exergy efficiency compared to the existing LAES systems, yielding 240.7% and 80.2% respectively. The thermodynamic and exergy analysis indicates that the proposed system is characterized by operational flexibility and exceedingly high efficiency. The results show that the system might play an essential role in power systems balancing. [Display omitted] •An advanced liquid air energy storage system is proposed.•LNG high-grade cold energy is used for air liquefaction.•Natural resources are introduced for air expansion.•ORCs are established in the system to improve energy efficiency.•Electrical round-trip efficiency reached 240.7%, and the system operates flexibly.