Use of phase change material (PCM) for the improvement of thermal performance of cold storage

Latent heat storage using phase change materials (PCMs) is one of the most efficient methods to store thermal energy. Therefore, PCM have been applied to increase thermal energy storage capacity of different systems. The use of PCM provides higher heat storage capacity and more isothermal behaviour during charging and discharging compared to sensible heat storage. Moreover, thermal energy storage (TES) systems for both heat and cold are necessary for good performance of many industrial processes. High energy storage density and high power capacity for charging and discharging are desirable properties of any storage system. These storage systems have been studied for many years addressing different problems of the used materials such as low thermal conductivity and segregation of the PCM. As regards to the criteria for selecting a suitable storage medium, the phase change materials (PCMs) are very attractive candidates in a thermal energy storage system and has drawn huge interest in recent years.1 The criteria include but not limited to the thermo-physical benefits, environmental effects and economy. The use of PCMs as storage media is by far the most effective and efficient way to storing thermal energy by exploiting the enthalpy of phase change as the storage mechanism.2 Among all possible phase change processes, the solid-liquid phase change is considered as the most suitable form for TES applications. The use of PCM in TES has many advantages over other forms of energy storage mediums, especially the sensible heat storage.3 Because of PCM’s high energy density (amount of heat energy storage per unit mass), it is possible to have much smaller and compact storage facilities compared to sensible heat storage types. The characteristic ability of PCM’s narrow temperature range during thermal energy charging and discharging periods has made it a suitable candidate for applications where smaller range of temperature variations are important.