Analysis of heat storage using Phase change material

Abstract

In many cases heat released from some of the renewable energy sources, cannot be directly used at the time of its generation. Therefore, facilities for thermal-energy storage (TES) which would allow delayed use of the harvested heat are very important for increase of the total process efficiency. An approach to thermal-energy storage is based on the use of the latent heat of phase-change materials (PCMs). The use of PCMs as thermal storage has a theoretical advantage over the sensible one because of their high latent heat that is released or accumulated during the phase-change process.
The advantage of PCM in thermal energy storage is in applications that needs narrow temperature range of supplying and storing thermal energy. The focus of the paper is on the analysis of thermal energy storage devices based on macroencapsulated PCM. The aim of this paper is to design a latent heat storage (LHS) system with spherical modules filled with PCM. Several measurements were performed on the experimental system under constant input conditions which shows that PCMs improve the release of heat from thermal storage and can supply heat or cold at a desired temperature level for longer time periods. With the help of the computer simulation program TRNSYS, a validation of the simulation model of the latent heat storage system Type 840 was carried out with the initial and boundary conditions of the experimental system. Finally, a parameter analysis for different diameters of the spherical modules was carried out using the simulation model.