Performance improvement for an open refrigerated display cabinet by limited coverage on the air curtain opening

Abstract

The opening of the open refrigerated display cabinet (ORDC) directly faces the environment and is vulnerable to the invasion of humid and warm ambient air, which causes high power consumption and excessive defrosting water. CFD simulation results show that the cold air leakage of the ORDC is mainly distributed in the lower areas on both edges of the ORDC opening. Limited coverage on the air curtain opening (LCO) is proposed by adding long narrow baffles at critical leakage positions to achieve an effective reduction in the heat load of the cabinet. According to simulation results, the ORDC equipped with a pair of 40 cm × 10 cm baffles can reduce the heat load by up to 33.8 % compared with the baseline prototype. The baffle improvement factor is defined to evaluate the baffles’ effect on refrigeration performance. The baffle with a small length (less than 20 cm) and a moderate width (4 cm–8 cm) is preferred to achieve a high baffle improvement factor. Moreover, the experiment on an ORDC is conducted to further investigate the effect of LCO on the refrigeration performance of the ORDC. The experimental results demonstrate that a pair of 40 cm × 10 cm baffles can reduce the 12 h power consumption and 12 h defrosting water weight of the cabinet by 30.1 % and 51.0 %, respectively, compared with the baseline prototype. Therefore, the LCO method has good application potential in saving electricity and reducing the defrost water in ORDCs.