Effect of Ethylene glycol as Phase Change Material in a Cold Storage Unit on retention of cooling

Many commodities such as food, medicines & vaccines are required to be kept in commercial cold storages within a specified temperature range. problems arise in these systems within times of failure, power cuts, or transportation. The absence of refrigeration leads to an increase in temperature within the system which may lead to spoilage of products stored inside. Phase change materials may pose as a promising solution as they absorb the latent heat of the system at the expense of the phase change absorbing, latent heat. Ethylene glycol is selected as the phase change material due to its high latent heat content and negligible hazards. The system incorporated with phase change material was found to retain the cooling effect after cut off. In this paper, for investigation we conducted four experiments namely 0/0%, 75/25%, 50/50%, 100/0% Ethylene glycol and water respectively as phase change material for studying the retention of cooling within the system during power failures. The result shows that the retention of cooling in cold storage unit with 100% Ethylene glycol phase change material is very low 50% Ethylene glycol and 50% water has more retention of cooling. This indicates that addition of water in the phase change material increases the retention of cooling in cold storage unit. (paper)