Dynamic simulation as a tool to support design decisions in a liquid air energy storage process

Dynamic behaviour and controllability play a critical role in the practical deployment of large-scale energy storage systems; however, liquid air energy storage processes are commonly evaluated under steady-state assumptions. This study develops a detailed dynamic process model of a liquid air energy storage charging system to investigate the interaction between process design, transient operation, and control performance. The model incorporates a realistic process concept with physically consistent representations of key components, including multi-stream plate-fin heat exchanger, cold storage, recycle streams, and practical control structures. The results demonstrate that designs identified as optimal under steady-state conditions may exhibit limited operability when subjected to realistic transient operation. Strong coupling between cold storage dynamics, recycle flows, and temperature control significantly influences system stability and liquid air production. Two novel process control schemes implemented in the dynamic model reveal that appropriate control configurations can extend stable operating periods, enhance cold utilization, and increase the total liquid yield by 20 % while reducing the specific energy consumption of liquefaction by 6 % without any hardware modifications. The analysis further highlights that neglecting dynamic interactions may lead to suboptimal design decisions and increased operational constraints. Overall, the proposed dynamic modelling framework provides a more realistic basis for early-stage design evaluation and operational optimization of liquid air energy storage systems. The findings emphasize the necessity of integrating process design and control considerations to ensure stable, flexible, and efficient performance in large-scale energy storage applications.