Static and dynamic modeling comparison of an adiabatic compressed air energy storage system
Résumé
Compressed air energy storage plant is a large scale potential energy storage system that provides longduration energy storage with a small response time. This technology is promising as it creates a balance between production and demand which thereby protects the electric grid. In fact, it makes the electric production of thermal and nuclear power plants more flexible and permits the increase of the contribution of intermittent renewable energies in electricity production. This paper presents a comparison between the static and dynamic modeling of an adiabatic compressed air energy storage system performed by a computer simulation using "Modelica". The studied storage plant is composed of 3 stages of compression, 3 stages of expansion, an underground cavern for air storage, 6 heat exchangers and a thermal energy storage system. Unlike the static model, the dynamic model takes into account the mechanical inertia of the turbo-machinery (compressors and turbines), as well as the thermal inertia of the heat exchangers. The developed dynamic model is based on the boundary conditions evolution of the different components of the storage cycle. It allows for examining the global behavior and evolutions of the storage system in time, and thus enables the study of the transient operations including start-up, shut-down, transient evolutions between different states and the continuous working state. Consequently, it enables studying the flexibility of the storage system and its ability to meet the electric grid requirements by evaluating the duration of the transient states. Furthermore, the efficiency losses due to the transient evolutions can be estimated.