Numerical Study of an Energy Storage Container with a Flat Plate Phase Change Unit Characterized by an S-Shaped Flow Channel

Abstract

China’s rapid economic development and rising energy consumption have led to significant challenges in energy supply and demand. While wind and solar energy are clean alternatives, they do not always align with the varying energy needs across different times and regions. Concurrently, China produces substantial amounts of industrial waste heat annually. Effective recycling of this waste heat could substantially mitigate energy supply and demand issues. The Mobile Thermal Energy Storage (M-TES) system is a key solution to address these challenges, as it helps manage the uneven distribution of energy over time and space. This article establishes a packaged M-TES based on a plate-type phase change unit. Based on different placement methods of the plate-type phase change unit, different inlet temperatures and phase change temperature differences, and different inlet and outlet directions, the complete charging and discharging process of the packaged phase change thermal storage system was simulated using ANSYS FLUENT 2022 R1 software. The results showed that during the heating process of the entire system, the horizontal placement of the plate-type phase change unit and the inlet and outlet methods of the heat transfer fluid (HTF) significantly improved the heating effect of the system, increasing it by 15.9%. Increasing the temperature difference between the inlet temperature of the heat transfer fluid and the melting temperature of the phase change material (PCM) from 4 K to 19 K can increase the melting rate of PCM by approximately 54.9%