EXPERIMENTAL AND THEORETICAL ANALYSIS OF PHASE CHANGE ENERGY STORAGE SYSTEM

Abstract

Thermal energy storage is becoming increasingly popular and technically attractive as one of the possible solutions for energy conservation and leveling of energy demand patterns. In particular, latent heat energy storage systems, presents a valuable energy storage option with attractive technical features in comparison to the sensible storage, because of its relatively low volume / energy ratio, together with its small change of temperature experienced during the charging and discharging processes. In the development of latent heat storage systems, research is underway in two directions, namely the investigation of the phase change materials (PCM) and of heat-exchangers. There is a need to generate experimental data for the thermo physical properties in the solid and liquid phases of PCMs in order to assist the effective and appropriate design of the storage system in terms of efficiency and cost effectiveness. The present study gives the details of the design analysis, fabrication details and analysis of the shell-and-tube type phase change energy storage system. Details of the experimental setup is also explained. It is seen that during melting process, phase change is not isothermal but occurs over a certain temperature range that was within the melting zone, but phase change occurs isothermally during solidification process. The radial temperature distributions for different time periods during Melting and -Solidification process are also presented. It is also found that increase in the mass flow rate results a higher heat transfer rates and consequent the phase change period is reduced substantially. Hence to get a faster storage of energy in the PCM, the mass flow rate should be high. Experimental model is validated with the theoretical analysis, and the results are quite acceptable.