Thermal, economic and food preservation performances of a refrigerated warehouse equipped with on-shelf phase change material

Low-temperature storage is an important way to maintain the quality of foodstuffs. Meanwhile, the massive power consumption and high operating costs of maintaining low temperatures are the main constraints for applying low-temperature storage applications. Utilizing phase change material (PCM) for low-temperature storage, which can postpone the electricity requirement, is a workable alternative. In the present study, numerical investigations are conducted to analyze the thermal, economic, and preservation performances in apple refrigerated warehouses (RWHs) with and without on-shelf PCM. The results show that employing on-shelf PCM can reduce the operating cost of the RWH by about 34.1% without deteriorating apple preservation performance in that the maximal difference in firmness reduction of apple is only about 6.57 %. In addition, the maximum air temperature in the pallet region of the RWH with on-shelf PCM varies from -1°C to 2.9°C, which is about 1.1℃ lower than that without on-shelf PCM during the storage process. Meanwhile, the maximum temperature rise rate of apple can be reduced from 0.58°C/h to 0.21°C/h with on-shelf PCM. However, the temperature of the apple on the edge of the pallet in the RWH with on-shelf PCM is higher than that in the RWH without on-shelf PCM in the last 6 hours of daily storage.