冷风通道内相变蓄冷对冷藏陈列柜性能影响研究OA

To suppress temperature fluctuations inside open-type food refrigerated display cabinets caused by periodic defrosting,an optimized scheme of installing phase change cold storage materials(PCM)in the cold air ducts was proposed.By analyzing the temperature characteristics of the cold air ducts,ND-1 type PCM with a phase transition temperature of-3℃was selected.The dosage of PCM was calculated based on the refrigeration system load,and the PCM was encapsulated into food-grade cold storage packs and integrated into the cold air ducts.Under conditions of 25℃and 60%relative humidity,the refrigeration performance of the refrigerated display cabinet before and after installing PCM was compared.The results show that compared with before the improvement,the vertical temperature uniformity of food packages on the first,third and fifth layers in the cabinet after the improvement has increased by 27.6%,21.2%,and 37.8%respectively,and the horizontal temperature uniformity has increased by 58.2%,15.9%,and 24.4%respectively.The average temperature of refrigerated food decreases by 1.12℃,the air curtain thermal suction coefficient decreases by 15.9%,the total energy consumption of the cabinet decreases by 6.2%,and the average air velocity attenuation rates at the supply and return air outlets decrease by 2.5%(supply air)and 6.5%(return air),respectively.This scheme effectively stabilizes the internal temperature field of the cabinet and improves energy efficiency.This study can provide a reference for the optimal design of food refrigerated display cabinets.