Transient prediction model of finned tube energy storage system based on thermal network

Abstract

This paper proposed a two-dimensional thermal network model to predict the output of the finned tube energy storage system during the melting stage to solve the fast calculation of latent heat storage cooling equipment for high-energy airborne weapons. The thermal network model introduces effective thermal conductivity to consider the effect of natural convection on the melting of PCM. Numerical simulation and experiment verify the accuracy of a single tube under various working conditions and actual size heat exchangers, respectively. Compared with single-tube numerical simulation, the maximum average outlet temperature error is 0.634 °C, saving 99% of the simulation time. Compared with the experiment, the maximum temperature error of outlet temperature is 4.91%, and the average temperature error is 1.18%. Results are found to be in good agreement with numerical simulation and experiment. The performance of heat exchangers is evaluated by effectiveness under different conditions, including fin geometry, material, and periodic inlet. The results show that the structure with smaller fin thickness and interval has better effectiveness and latent heat storage, more benefits from increasing the fin thermal conductivity, and better stabilizes the outlet under the periodic inlet. It provides a reference for designing and optimizing energy storage systems.