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In order to improve the performance of refrigerated display cabinet, decrease the food temperature, improve the uniformity of food temperature and restrain the temperature fluctuation during the defrosting time, a new kind of composite shelf is designed for the food vertical open refrigerated display cabinet (VORDC), which is based on the heat pipe technology and the cool storage characteristics of phase change materials (PCMs) among the heat pipes. Experimental results show that the novel composite shelf can enhance the heat transfer between food and shelf, reduce the core temperature of food, decrease temperature fluctuation in defrosting process and reduce the temperature difference along height, width and depth direction. Compared with the normal shelf, the temperature differences of food packages on both sides of the composite shelves (RT3, RT4 and RT5) are reduced by 40%, 80% and 40%, respectively. The average temperature of food packages is reduced by 13.7–32% and the temperature fluctuation of food packages is reduced by 53.3–83.3% during defrosting. For these kinds of composite shelves, the temperature of food packages of RT4 composite shelf is lowest, and the average temperature of food packages at each layers and rows are controlled in 5 °C. This novel composite shelve can effectively reduce the temperature rise during defrosting, and improve the performance of VORDC obviously.

A multi-scale approach has been formulated in a previous work. The influence of HVAC system in supermarket on the performance of vertical open refrigerated display cabinet (VORDC) is considered. The influence is evaluated by varying the supply air temperature and velocity at the diffusers of HVAC. The computational results show that there is a direct interaction between the HVAC system and VORDC in supermarket. When the supply air temperature of HVAC system decreases from 19 °C to 16 °C, the electricity energy input in VORDC system decreases by 6.36%, and the highest products temperature is reduced by 0.18 °C. When the diffuser supply air velocity of HVAC system increases from 2.0 m/s to 3.5 m/s, the energy input in VORDC system decreases by 23.4%, and the highest product temperature reduces by 0.4 °C.

In this paper, the effect of the back panel structure on the performance of fluid flow and heat transfer of vertical open refrigerated display cabinets (VORDC) is presented by experiments and numerical simulation. Experimental tests are performed to validate the accuracy of numerical predictions. The characteristics of heat transfer and fluid flow of VORDC are investigated at the different locations of the perforations of back panel at the same porosity and the different flow ratios between back panel and air curtain at different porosities. By comparing numerical results with experimental results, the predictive abilities of the computational model have been revealed. Further computational results have also shown that less than 3% porosities can provide a better performance in the VORDC; the location of perforations has a minor influence on the temperature distribution of products. Furthermore, the suitable porosities in the back panel among the shelves are more likely to improve the uniformity of products temperature in the VORDC. As a result, the overall uniformity of product temperature inside the refrigerated display cabinet and the maximum deviation values of product temperature have been improve to 41% and 49%, respectively. The present study can provide the theoretical guide for the design of the narrow VORDC.