What should be paid attention to to make cold storage more energy-efficient?

What should be paid attention to to make cold storage more energy-efficient?

1. The index to reduce the unit heat flow of the enclosure structure of the cold storage. In the design of the cold storage, the unit heat flow q of the outer wall of the low-temperature cold storage is generally about 11.63W. If q can be reduced to 6.9W, it is for a 5000T~10000T class For low-temperature cold storage, it is estimated that power costs can be reduced by about 10%. Of course, the reduction of the unit heat flow index means that the insulation layer of the envelope structure should be thickened, and the one-time investment cost has increased. However, compared with the reduction of the cold storage regular operating cost, then, whether from an economic point of view or from From the perspective of technical management, it is reasonable and cost-effective to reduce the unit heat flow index of the cold storage enclosure structure.

2. According to different refrigerated foods and different storage periods, determine the corresponding storage temperature value. For various foods, especially meat, the biochemical changes during low-temperature storage and the extent to which the growth and reproduction of hypothermic bacteria are inhibited can be determined. If the storage temperature is not more than half a year, the storage temperature is generally -18—-15℃; for storage more than half a year, a low temperature of ≤-18℃ should be used; for foods with large fat content, such as For fish with a lot of fat, in order to prevent the oxidation of fat during the low-temperature storage period, the storage temperature should be lower than -18℃, which is -24 to -20℃.

　　 It can be seen that after adopting different storage temperatures, for certain foods, especially for short-term storage, it is equivalent to increasing the evaporation temperature of the refrigeration system, thereby increasing the refrigeration capacity of the refrigeration compressor. To achieve energy saving.

3. Reduce the temperature between the refrigerant evaporation temperature and the temperature in the cold storage. When the temperature in the cold storage is constant, as the temperature difference between the evaporation temperature and the temperature in the storage decreases, the evaporation temperature can be increased accordingly. At this time, if the condensation temperature of the cold storage is not maintained Change means that the cooling capacity of the refrigeration compressor is increased. It can also be said that when the same cooling capacity is obtained, the power consumption can be reduced.

　　According to estimates, when the evaporation temperature drops by 1℃, it will consume 3-4% more electricity. In addition, reducing the temperature difference is also extremely beneficial to reducing the dry consumption of food stored in the warehouse. Because a small temperature difference can make the warehouse obtain a relatively large relative humidity, it can slow down the degree of heat load exchange in the air in the warehouse, so as to reduce the dry consumption of stored food, especially for the stored food that has not been packaged. The temperature difference.

　　 4. Two-speed or variable-speed fans are used in the freezing room. In the process of food freezing, the heat released is actually an uneven exothermic process, and the corresponding cooling capacity of the cooling equipment is also uneven. The freezing process of food can be divided into three stages, namely the first stage is the cooling stage, the temperature of the food drops from >0℃ to about 0~C; the second stage is the ice crystal formation stage, the food temperature drops from about 0~C About -5°C; the third stage is the freezing and cooling stage, where the food drops from -5°C to about -15°C.

From the above analysis, it can be seen that of the three stages of food freezing, the second stage requires a large amount of refrigeration. At this time, all equipment in the freezing room must be put into operation. In the first and last stages, due to the low heat load per unit time, The wind speed and volume of the air cooler can be appropriately reduced to achieve the purpose of saving electric energy. If the air cooler used in the freezing room is only one speed and cannot be adjusted, it will affect the adjustment of the circulating air volume and indoor blowing speed during the freezing process. Thereby increasing power consumption.

　　5. Comprehensive utilization of the cold storage building space to give full play to the multi-functional role. There are high and low seasons in the use of freezing rooms, and the off-season is greater than the peak season. In the off-season, it can also be used as a refrigerating room to store foods in packaging. This not only increases the use efficiency and economic benefits; reduces various damages to the enclosure structure, and solves the temperature impact on the adjacent cold storage room; speeds up the food freezing speed, shortens the time, and makes the food quality better; it can also be used with cold air The use of the machine and the requirements of ultra-low temperature storage of special food.