Influence of metal encapsulation on thermophysical properties and heat transfer in salt hydrate phase change material for air conditioning system

Abstract

Phase change materials (PCM) are gaining increasing attention as a cold energy storage technology for air conditioning systems due to their potential to reduce electrical grid loading, energy consumption, and electricity costs. However, realizing the full potential of PCM-based cold energy storage in practical applications is constrained by low cold energy transfer efficiency within air conditioning systems. This study addresses this challenge by exploring the encapsulation of salt hydrate PCM using six different metals to enhance heat transfer efficiency. Additionally, the corrosion behaviors of the PCM towards these metals were thoroughly evaluated. Notably, copper demonstrated the highest corrosion rate, and the resulting corrosion products, particularly from copper and brass, were found to substantially reduce the energy storage capacity of PCM. Moreover, PCM encapsulated into aluminum alloy exhibited higher heat transfer efficiency than that of stainless steel. In light of these findings, aluminum alloy is recommended as the optimal choice for PCM encapsulation, given its corrosion resistance and minimal effect on thermal properties. This research provides crucial insights for selecting appropriate metals to enhance the efficiency and durability of air conditioning systems utilizing salt hydrate PCM.