Melting effect in triplex-tube thermal energy storage system using multiple PCMs-porous metal foam combination

摘要

The study was performed on the melting performance of phase change materials (PCMs) inside a triplex heat exchanger with double-sided heat transfer. The purpose of numerical simulation in this paper was to investigate the effects of using three-layer PCM with different melting temperatures instead of single-layer PCM and also the effect of their combination with Al6061 metal foam to compensate for the major problem of low thermal conductivity of PCMs. According to research, despite the reduction of melting rate in pure three-layer PCM compared to pure single-layer PCM, the addition of Al-6061 metal foam to them caused the melting rate of three-layer PCM to be superior. By identifying porous three-layer PCM as a better case, the effect of changing the porosity arrangement of layers with constant average porosity of 0.95 was investigated. In the next step, this study was performed on different porosity numbers. As expected, with decreasing the porosity, the melting rate increased due to increased heat transfer. To achieve higher efficiency, the effect of heat transfer fluid (HTF) temperature was also investigated and plotted. The relevant results showed the significant effect of temperature change at the melting time of the system. Therefore, every case or combination of any of the above studies, which increased the melting efficiency, can be of great help in optimizing energy storage heat exchangers based on latent heat.