Do you know the common knowledge of cold storage?

1, Classification of Cold Storage and Storage Plates
Cold storage is usually divided into three temperatures: high temperature, medium low temperature, and ultra-low temperature. Different ingredients require different temperatures.
High temperature cold storage, also known as refrigerated and fresh-keeping cold storage, typically has a temperature above 0 ℃ and is mainly used for storing fruits, vegetables, eggs, medicinal herbs, wood preservation, and dry materials. Maintain the temperature at around 0 ° C and use a cold air blower for blowing and cooling.
Low temperature cold storage, also known as high-temperature freezing cold storage, is typically used to store meat, water products, and goods suitable for this temperature range, with temperatures typically below -18 degrees Celsius.
Low temperature cold storage, also known as freezing storage or frozen cold storage, usually has a storage temperature of around -20 ° C~-30 ° C, and uses air coolers or specialized freezing equipment to freeze food.
Ultra low temperature cold storage, with a temperature range of ≤ -30 ℃, is primarily used for quick freezing of food, industrial experiments, medical and other special purposes. Compared to the above three types, its usage in the market is slightly smaller.
Medium temperature cold storage usually uses 100MM thick cold storage panels, while low-temperature and frozen storage usually use 120MM or 150MM thick panels. The foam density of cold storage panels is between 38KG and 40KG per cubic meter according to national regulations.
The protective materials for cold storage panels mainly include the following:
A. Embossed color steel plate;
B. Stainless steel plate;
C. Color zinc steel plate;
D. Salt coated steel plate;
E. Standardize the floor slab;
The selection of cold storage panels is very important for cold storage, as cold storage is different from other warehouses and requires high environmental conditions such as temperature and humidity. So when selecting cold storage panels, attention should be paid to the raw materials and insulation strength of the panels. Choosing the right panels can effectively protect the cold storage.
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2, Calculation of storage capacity for cold storage
Calculate the tonnage of the cold storage: (based on the design specifications of the cold storage and relevant national standards for cold storage capacity): The internal volume of the refrigeration room multiplied by the volume utilization coefficient multiplied by the unit weight of food=tonnage of the cold storage.
The first step is to calculate the actual available and stored space inside the cold storage: the aisle space that needs to be reserved in the warehouse, the location occupied by internal equipment, and the space that needs to be reserved for internal air circulation (which can be estimated or calculated according to the volume utilization coefficient in Table 1);
The second step is to search for the weight of items that can be stored in each cubic meter of space according to the category of inventory items, and multiply it to obtain how many tons of products can be stored in the cold storage;
500-1000 cubic meters=0.40;
1001 to 2000 cubic meters=0.50;
2001-10000 cubic meters=0.55;
10001-15000 cubic meters=0.60.
Note: Based on our experience, the actual available capacity is greater than the capacity utilization coefficient defined by the national standard. For example, the utilization coefficient of a cold storage with a capacity of 1000 cubic meters according to the national standard is 0.4. If scientifically and effectively placed, the actual utilization coefficient can generally reach 0.5-0.6.
Unit weight of food in the activity cold storage: frozen meat: can store 0.40 tons per cubic meter; Frozen fish: can store 0.47 tons per cubic meter; Fresh fruits and vegetables: 0.23 tons can be stored per cubic meter; Mechanized ice: can store 0.75 tons per cubic meter; Frozen sheep compartment: capable of storing 0.25 tons per cubic meter; Bone removal and meat cutting: each cubic meter can store 0.60 tons; Box packaged frozen poultry: can store 0.55 tons per cubic meter.
3, Maintenance and upkeep of cold storage
1. After the installation or long-term shutdown of cold storage and refrigeration equipment, comprehensive testing and debugging should be carried out before reuse. Under normal conditions, professional refrigeration technicians should guide the use of the equipment.
2. Attention should be paid to the collision and scratching of hard objects on the cold storage body and outer body during use. Because it can cause dents and rust, and in severe cases, it can lead to a decrease in local insulation performance.
3. Due to the fact that prefabricated cold storage is made up of several insulation boards, there are certain gaps between the boards. During construction, these gaps will be sealed with sealant to prevent air and moisture from entering. So, timely repair of some sealing failure areas during use. We must resolutely prevent the occurrence of cold escape phenomenon.
4. Generally, insulation boards are used on the floor of small prefabricated cold storage facilities. When using the cold storage, it is necessary to prevent a large amount of ice and water from being stored on the floor. If there is ice, hard objects should not be used to hit and damage the floor during cleaning.
5. Initial operation of the unit: It is necessary to regularly observe the oil level and return oil condition of the compressor, as well as the cleanliness of the oil. If the oil is dirty or the oil level drops, it should be resolved in a timely manner to avoid poor lubrication.
6. Regularly clean the air cooler to maintain a good heat exchange condition. Check whether the motor and fan rotate flexibly, and if there is any blockage, add lubricating oil; If there is abnormal friction sound, replace the bearings with the same model and specifications to clean the dirt on the fan blades, coils, and water collection tray. For the air cooling unit, it is necessary to regularly check the condenser. If scaling occurs, the scale should be removed in a timely manner.
7. For the evaporator: it is necessary to regularly check the defrosting situation and whether the defrosting is timely and effective, which will affect the refrigeration effect and cause the refrigeration system to return liquid.
8. Regularly observe the operating status of the compressor; Check the exhaust temperature and pay special attention to the operating status of the system during seasonal operation. Adjust the system's liquid supply and condensation temperature in a timely manner.
9. Listen carefully to the sound of the compressor and condenser fan operation, promptly handle any abnormalities, and check the vibration of the compressor, exhaust pipe, and foundation. Check if there is any abnormal odor in the compressor
10. The internal cleanliness of the initial system is poor, and the refrigeration oil needs to be replaced after 30 days of operation. For systems with high cleanliness, they should be thoroughly replaced after six months of operation (depending on the actual situation).
11. Refrigeration technicians conduct an annual inspection and maintenance of the compressor. Check the oil level and color of the compressor. If the oil level is lower than 1/2 of the observation glass, the cause of the oil leakage should be identified and the fault should be eliminated before refilling with lubricating oil; If the oil has changed color, the lubricating oil should be completely replaced. Check if there is air in the refrigeration system, and if so, exhaust the air.
12. Regularly check and confirm whether the voltage of the power supply meets the requirements, which should be 380V ± 10% (three-phase four wire). When the cold storage equipment is not used for a long time, the main power supply of the fresh-keeping cold storage should be cut off, and the cold storage equipment should be ensured not to be damp or contaminated by other substances such as dust.
13. Regularly check whether the connecting pipes and valves of the refrigeration unit are secure and whether there is refrigerant leakage (oil stains usually appear in the leakage areas).