Liquid air energy storage system based on fluidized bed heat transfer

Liquid air energy storage (LAES) is a large-scale energy storage technology that has gained wide popularity due to its ability to integrate renewable energy into the power grid. Efficient cold/heat energy storage, which currently mainly includes solid-phase packed beds and liquid-phase fluids, is essential for the LAES system. However, the current heat/cold energy storage methods have limitations, such as the risk of flammability and explosion, the dynamic effect of the thermocline, and expensive investment. To address these limitations, a novel LAES based on fluidized bed heat transfer (FB-LAES) is proposed, and quartz sand is adopted as the heat/cold energy storage material. A thermodynamic model is developed, and the effects of heat exchanger design con-ditions and fluidization parameters on system performance are investigated, which indicates that the lower air-side/particle-side pressure drop and higher particle transport coefficient (PTC) favor the efficiency improvement of the FB-LAES system. The comparison demonstrates that the round-trip efficiency (RTE) of the FB-LAES system can reach 58.76% without stringent design conditions, while the RTE of the LAES system with traditional solid-phase (packed bed) and liquid-phase (methanol and propane) cold energy storage are 48.76% and 57.46%, respectively.