Cold storage using phase change material in refrigerated display cabinets: experimental investigation

Abstract

Refrigerated display cabinets are the main energy consumers in supermarkets. Cold thermal energy storage (CTES) using phase change materials (PCM) can significantly reduce temperature variations in a display cabinet during loading of warm items, defrost cycles or power outages. This contributes to reduced loss in product quality and less food being wasted. With an increasing share of intermittent renewables in the power grid, PCM-enhanced systems benefit from low-cost electricity during periods with low demand. Stored excess cooling can be later used during periods with high demand. A CTES prototype was developed using water as PCM integrated in an evaporator. This system was experimentally compared to a reference case not using the PCM capabilities. The results show the potential for PCM-CTES to consistently keep the cabinet air temperature low, thus prolonging shelf life and product quality. Charged PCM-CTES systems provide cooling for several hours after the main evaporator is deactivated. Keywords: Refrigerated Display Cabinet, Thermal Energy Storage, Cold Storage, Phase Change Material, Supermarket Refrigeration, Defrost Cycle.