Classification, capacity calculation, and maintenance inspection of cold storage

          Classification, capacity calculation, and maintenance inspection of cold storage

1、 Classification of cold storage and storage panels

Cold storage is usually divided into three temperatures: high temperature, medium low temperature, and ultra-low temperature. Different ingredients require different temperatures, and nowadays cold storage manufacturers can satisfy the needs of consumers at all levels.

High temperature cold storage

High temperature cold storage, also known as refrigerated and fresh storage, is typically used to store fruits and vegetables, eggs, medicinal materials, wood, and dry materials at temperatures above 0 ℃. Always maintain a temperature of around 0 ° C and use a cold air blower for blowing and cooling.

Medium and low temperature cold storage

A medium to low temperature cold storage, also known as a high temperature frozen cold storage, is typically used to store meat, water products, and products suitable for that temperature range, typically within -18 degrees Celsius.

Low temperature cold storage

Low temperature cold storage, also known as frozen storage or frozen cold storage, usually has a temperature of around -20 ° C~-30 ° C, and is used to freeze food through cold air fans or specialized freezing equipment.

Ultra low temperature cold storage

Ultra low temperature cold storage, ≤ -30 ℃ cold storage, is mainly used for quick freezing food, industrial experiments, medical and other special purposes. The use on the market is slightly smaller compared to the above three.

Medium temperature cold storage

Usually, 100mm thick cold storage panels are used, while 120mm or 150mm thick panels are usually used for low-temperature and frozen storage. The foam density of cold storage panels is between 38KG and 40KG/cubic meter according to national standards.

The protective materials for cold storage boards mainly include the following:

A. Embossed color steel plate (commonly used);
B. Stainless steel plate (not commonly used);
C. Color zinc steel plate (not commonly used);
D. Salinized steel plate (not commonly used);
E. Standard floor plate: 1.0mm galvanized plate

The selection of cold storage panels is very important for cold storage, as cold storage is different from other warehouses and requires high temperature, humidity, and other environmental factors. So when selecting cold storage boards, attention should be paid to the raw materials and insulation strength of the boards. Choosing the right board can effectively protect the cold storage.

2、 Calculation of Cold Storage Capacity

Calculate the tonnage of the cold storage: (calculated based on the design specifications for cold storage and relevant national standards for cold storage capacity);

The internal volume of the refrigeration room × Capacity utilization coefficient × Unit weight of food=tonnage of cold storage.

The first step is to calculate the actual available space for storing items inside the cold storage: the internal space of the cold storage - the aisle space that needs to be left 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 per cubic meter of space according to the category of inventory items, and multiply this to determine how many tons of products can be stored in the cold storage;

500-1000 cubic meters=0.40;
1001-2000 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 volume of 1000 cubic meters in the national standard is 0.4. If scientifically and effectively arranged, 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: can store 0.23 tons per cubic meter;
Mechanized ice: can store 0.75 tons per cubic meter;
Frozen sheep chamber: can store 0.25 tons per cubic meter;
Bone removal and meat cutting: can store 0.60 tons per cubic meter;
Box packed frozen poultry: can store 0.55 tons per cubic meter.

3、 Selection and maintenance of cold storage

1. Maintenance of the sealed parts of the cold storage. As the preservation 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, in use, timely repair some sealing failure parts.

2. The electrical equipment of the fresh-keeping cold storage equipment should avoid moisture to prevent electric shock accidents caused by leakage.

3. Regularly check and confirm whether the voltage of the power supply meets the requirements, and the voltage should be 380V ± 10% (three-phase four wire). When the cold storage equipment is not in use 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.

4. All refrigerant insulation pipes must be wrapped with wrapping tape, and steel sleeves must be used when passing through the floor slab.

5. 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 leaking areas).

The most practical method for leak detection is to use a sponge or soft cloth dipped in detergent, rub it to foam, and then evenly apply it to the area to be detected. Observe for a few minutes. If there is leakage, bubbles will appear. Mark the leakage area and then tighten or weld it (to be repaired by professional refrigeration personnel).

6. Control line operation: All control lines are bundled and laid along the refrigerant pipe using shielded wires, and some indoor controllers are concealed through pipes. It is prohibited to bundle power and control lines together to prevent interference.

7. Regularly check if the power supply voltage is normal (three-phase four wire), and check if the protection function of the power supply main switch is normal and effective.

8. The lifting point can be determined based on the number of fixed points on the top of the warehouse. It is best to install a pair of chain blocks on each hanger cross arm, which is beneficial for alignment and adjustment during fixation. When lifting, there should be a dedicated person to command, and the person pulling the chain should not stand directly below the pipe. Lift at each lifting point simultaneously, maintaining a consistent and stable height. After lifting and leveling, weld and fix it with the fixed lifting point on the top of the warehouse. This method is just to prepare more long backlinks.