Experimental study of heat transfer intensification by using a novel combined shelf in food refrigerated display cabinets (Experimental study of a novel cabinets)

Open-type display cabinets are widely used in supermarkets for chilling and displaying food. These cabinets use convective heat transfer to cool the food, and they often show uneven food temperature distribution and obvious food temperature rise during defrost process. A novel design for display cabinet’s shelf is proposed in this paper. In the new design heat pipes of new structure and appropriate phase change materials (PCM) are equipped in the shelf. Comparison tests of two prototypes (one with heat pipe only and the other with both heat pipe and PCM) and original cabinet have been conducted. The tests results show that improved heat transfer and lower food temperature are achieved by the two new shelves. The new shelf with heat pipes only leads to lower food core temperatures of approximately 3.0 to 5.5 °C compared to the original design. The new shelf with both heat pipes and phase change materials reduces 1.5 °C of food temperature rise during defrost period and improves the uniform of food temperature distribution while the energy consumption is basically the same as that of the original cabinet.