Decision-making analysis of air supply strategies for high rack cold stores

Abstract

The thermal performance of a high rack cold store is related to the quality of fresh fruit and vegetable preservation. As the complex air supply strategies, a comprehensive evaluation of the thermal and airflow performance needs more than one demand. Therefore, the Z-score method was used to evaluate the thermal and airflow performance of the high rack cold store in this paper. The Z-score considered the energy utilization coefficient, non-uniformity coefficient and Air Diffusion Performance Index (ADPI). Firstly, a numerical simulation model of a high rack cold store was developed and validated. The effects of air supply form, air supply angle and air supply velocity on thermal performance and flow properties were then investigated. The velocity, temperature and pressure distribution were analyzed. Based on the previous data, the air supply strategies of the high rack cold store were evaluated with the proposed Z-score method, and the results proved that it could be utilized as the multi-indicator comprehensive analysis method for the high rack cold store. The cooling effect and the thermal uniformity of the vertical wall attached ventilation was excellent in a high rack cold store. When the air supply angle is −90°, the high rack cold store has a more uniform and reasonable temperature field. Considering the energy consumption of fans, the optimal air supply velocity was 11.7 m·s−1. Those results could provide a reference for the design of air supply form in the high rack cold store.