Analysis of cold thermal energy storage using phase change materials in freezers

Abstract

Today, the use of PCM is widespread throughout the world. PCMs are used in various industries, including buildings and refrigeration systems. PCMs are used to improve the energy efficiency of freezers. According to the high latent heat of PCMs, they have a good energy storage capacity. Adopting PCM in the system can reduce energy fluctuations and improve energy consumption. In this study, cold energy for energy storage from PCM is exploited in order to reduce energy usage. In addition, all types of PCMs and the proper category for freezer brakes are assessed. Heat and energy exchange methods for PCM solutions are discussed. Then, as a complementary method, the enthalpy method is selected, and energy equations based on this method are proposed. For the system, two PCMs of water and ethylene glycol are considered, and each is evaluated in terms of charge. The results showed that the use of water as PCM in the first 100 min, consumes only 63% of its energy, while in the absence of PCM, the system loses almost 90.9% of its energy after 100 min. By replacing ethylene with water, in the first 500 min, only 35.97% of the energy is released from the system, and the rest of the power remains. This research indicates that the adoption of PCM leads to optimization in energy consumption and storage.