Current development status of cold storage evaporator and prospects for the future

Current development status of cold storage evaporator and prospects for the future

Chinese agricultural output has always been the number one in the world. The output of grain, vegetables, meat, eggs, aquatic products or fruits has shown an increasing trend, providing extremely abundant raw materials for the food industry. Since the reform and opening up, the cooling in the production process of the food industry, the freezing and preservation of products, and the refrigerated transportation are inseparable from cold storage equipment. It is under this background that the cold storage evaporator came into being.

　　 Food cold storage is an important facility for food freezing, processing, storage and circulation, and it occupies an important position in the national economy. In the food industry, with the rapid advancement of food cold storage technology, the reform of China's food structure and packaging forms, especially the rapid development of the small-package frozen food industry, food freezing methods have undergone major changes, starting from the 1950s and 1960s The widely used intermittent, slow warehouse-type and shelf-type freezing rooms have been changed to use fast and continuous freezing devices (tunnel, spiral, fluidized). The temperature of the freezing chamber in Dongguan Ganghua has dropped from -33 to -35°C to -40 to -42°C, thus speeding up the freezing speed and improving the quality of frozen products. At the same time, with the application of automatic control technology for food cold storage refrigeration systems. Large and medium-sized food cold storages have basically realized real-time display and automatic recording of storage temperature, refrigeration system pressure, equipment operating status, etc., and with the large-scale application of screw compressors in cold storage, PLC automatic control has gradually replaced the traditional Manual control method.

At present, according to incomplete statistics, the energy consumption of the refrigeration system of the cold storage is about 110 degrees per ton of white meat frozen (the power consumption index is as high as 180 degrees/ton, and the power consumption index is as low as 70 degrees. KWh/ton); for freezing one ton of frozen food in the freezing room, the average power consumption is 0.4 kWh/day (the power consumption index per ton is as high as 1.4 kWh/day, and the power consumption index is as low as 0.2 per ton. KWh/day); for refrigerating a ton of food in the cold storage room, the average power consumption is 0.5 kWh/day (the power consumption index is as high as 1 kWh/day, and the power consumption is as low as 0.3 kWh/day).

　　According to statistics, my country's production enterprises have produced about 800 large, medium and small assembly warehouses, and about 25,000 sets (seats) of indoor prefabricated food cold storage. In 2015, only 38 fresh-keeping cold storages were newly built in Shanghai, accounting for 40% of Shanghai.

　　When it comes to specific energy-saving measures for refrigerated cold storage, there are generally these points:

　　 1. Reduce the intrusion of hot and humid air through the opening of the refrigerator door;

　　2. The envelope structure adopts energy-saving insulation layer thickness;

　　3. Adopt refrigeration compressors with high COP (single-stage screw compressors or single-stage two-stage screw compressors), high-efficiency water pumps and fans;

　　 4. Evaporative condensers are more widely used;

　　5. Reasonable adjustment of refrigerator energy;

　　 6. The evaporator adopts a reasonable defrosting method and defrosts in time.