Numerical analysis of demolition waste‐based thermal energy storage system for concentrated solar power plants

Abstract

AbstractThermal energy storage (TES) is an enabling system that provides uninterrupted energy from concentrated solar power (CSP) plants. Packed‐bed TES systems have great opportunity to significantly enhance the cost‐effectiveness, efficiency, and sustainability of CSP plants by employing an affordable and sustainable packing material. The objective of this study is to design a demolition waste‐based packed bed TES system with a maximum storage capacity of 40 kWh, specifically tailored to store heat within the temperature range of 290°C to 565°C using solar salt as heat transfer fluid (HTF), thereby making it suitable for integration into CSP plants. Performance and thermal behavior of demolition waste‐based packed‐bed TES system was assessed through numerical analysis. The results demonstrate that a high discharging efficiency of 76.0% was achieved when the HTF flow rate was set at 100 kgh−1. However, it is important to note that at lower HTF flow rate, heat loss increases, leading to a decrease in discharging efficiency to 70%. The experiment also revealed a uniform thermal gradient within the packed‐bed TES system, up to a fluid flow rate of 300 kgh−1. It is worth mentioning that lower flow rates can further improve the stratification effect; however, they may also result in increased heat loss and reduced storage capacity. Based on these findings, an optimal flow rate range of 100 to 200 kgh−1 is recommended to achieve the best performance for the packed‐bed TES system.