Small cold storage
Small cold storage with air-cooled unit as the preferred form, it has the advantages of simple, compact, easy to install, convenient operation, less auxiliary equipment and so on. Generally, color steel plate is used as panel, rigid polyurethane foam is used as insulation material, and the library body has the characteristics of good rigidity, high strength, good thermal insulation performance, flame retardant and so on. The small cold storage body generally adopts the eccentric hook connection of the embedded parts inside the board wall or on-site foaming and solidification, which has good sealing and easy installation, easy installation, disassembly and handling, small amount of on-site construction and installation engineering, labor-saving, good quality and fast results. It can meet the needs of different uses and is suitable for use in various industries and sectors.
Product Introduction
Cold storage generally refers to facilities that are refrigerated with various equipment and can be artificially controlled and maintained at a stable low temperature. Its basic components are: refrigeration system; electronic control device; Warehouse with certain thermal insulation performance; Outbuildings, etc. The refrigeration system mainly includes a variety of refrigeration equipment, refrigeration equipment is the heart of the cold storage, it produces the cooling capacity, to ensure the cold source supply in the warehouse. The electronic control device is the brain of the cold storage, which directs the refrigeration system to ensure the supply of cold energy. The warehouse with certain thermal insulation performance is a place for storing and preserving agricultural products, and its role is to maintain the stability of the low temperature environment, usually the thermal insulation performance is said to be heat preservation. The good thermal insulation structure of the warehouse can maximize the cooling capacity manufactured by the refrigeration equipment in the warehouse to leak outward, in turn, it is to minimize the leakage of heat outside the warehouse into the warehouse, which is also the main difference between the cold storage and the general house.
Small cold storage is generally divided into two types: indoor type and outdoor type
1. Ambient temperature and humidity outside the cold storage: the temperature is +35°C; The relative humidity is 80%.
2. Set temperature in cold storage: fresh-keeping cold storage: +5~-5°C; Refrigerated cold storage: -5~-20°C; Low temperature cold storage: -25 °C
3. Food temperature in cold storage: L-level cold storage: +30°C; Class D and J cold storage: +15°C.
4. The effective volume of stacking of prefabricated cold storage is about 69% of the nominal volume, and the correction factor of 0.8 is multiplied by 0.8 when storing fruits and vegetables.
5. The daily purchase volume is 8~10% of the effective volume of the cold storage.
Small cold storage design points
Small prefabricated cold storage with a temperature below 0 degrees (-16 degrees) needs to be set up on the ground (under the library plate) 10# channel steel overhead to make it naturally ventilated. Small cold storage, the temperature in the cold storage is 5~-25 degrees, and the cold storage board can be directly in contact with the ground, but the ground should be flat. If the requirements are high, wooden strips can be placed under the cold storage and overhead to enhance ventilation; Channel steel can also be placed under the cold storage to enhance ventilation.
Small cold storage installation
The lap of wall panel and roof plate, the reinforcement of wall panel and steel frame, and the lifting of ceiling panel and frame are all equipped with special combination accessories and special forms to ensure that the cold storage insulation is airtight, firm and safe. Each prefabricated panel is surrounded by high-strength locks for easy assembly.
Installation display of small cold storage
How to calculate small cold storage plates
One. Design Objectives:
An indoor assembly small cold storage with a tonnage of 40t, a low temperature of -25 °C and a high temperature of 30 °C (that is, -25 °C in the warehouse and 30 °C outside the warehouse) was built, and the address was Hangzhou at 30 ° north latitude.
Two. Calculation instructions
1. Cold storage structure
Therefore, the size of the cold storage is designed as length× width× height = 26×16×5, divided into two small rooms with the same volume, and its design plan is as follows:
Cold storage is placed on the north facing south.
The structure of assembled cold storage and user requirements for cold storage:
1. Length× width× height = volume of the cold storage ________ m3.
2. Temperature in the warehouse: preservation: +5--5 °C, refrigeration and freezing: 0--18 °C Low temperature: -18--30 °C. The thickness of the library plate.
3. The specification and size of the warehouse door: the direction of opening the requirements of wide × high door locks.
4. The storage capacity of cold storage, the daily purchase and shipment volume.
5. The refrigerator is air-cooled or water-cooled. The chiller is air-cooled, and the user only needs to choose the placement position. The refrigerator is water-cooled and the user also needs to configure: the specification and size of the pool, length× width× height = ________
6. Configuration of evaporator: ceiling air cooler, floor air cooler or pipe ________.
How to choose the right small cold storage
1. Determine the size of the cold storage (length×width × height) according to the tonnage of the goods stored by themselves, the daily purchase and shipment volume and the size of the building, and the installation environment of the cold storage should be clean, dry and ventilated.
2. According to the stored items, choose to determine the temperature preservation storage in the warehouse: +5--5 °C, refrigerated and frozen: 0--18 °C, low temperature storage: -18--30 °C).
3. According to the characteristics of your own building and the local water source, choose the refrigeration method of the refrigerator, generally with air cooling and water cooling. (Users of the refrigerator are air-cooled only need to select the placement location, and users of the refrigerator are water-cooled and need to configure the placement of pools or deep-water wells, circulating water pipelines and pumps, and cooling towers).
What is cold storage and freshness:
Storage and preservation or called fresh-keeping storage, its main content is preservation, that is, for a long time, to maintain the original quality and freshness of some agricultural products to the greatest extent, that is, fresh agricultural products, after a period of fresh-keeping storage, is still freshly picked or close to the fresh state and quality when it was just picked.
The relationship between temperature and the preservation and storage of agricultural products:
After harvesting, agricultural products are still a living body, and in the process of storage, if it wants to maintain life, it must stop consuming its own stored nutrients, thus gradually losing its nutritional value and fresh quality. In addition, pests will also store nutrients of agricultural products as food, resulting in spoilage of agricultural products, loss of freshness and edible value. How to make the live body of agricultural products retain nutrition and fresh quality, temperature is the most important influencing factor. Generally speaking, the lower the temperature, the less nutrients the product consumes, the worse the pests and diseases, and the longer the fresh quality is maintained. At the same time, the smaller the temperature change, the better the fresh-keeping effect. The fresh-keeping temperature is not infinitely low, because when the temperature is so low that the product cannot stand it, cold or frost damage will also occur. Therefore, fresh-keeping storage requires a relatively stable suitable low temperature condition. The optimum temperature for freshness of most agricultural products is about 0°C.
Optimal temperature for maintaining the preservation and storage of agricultural products:
The temperature is constantly changing with the season of the year and the time of day, and most agricultural products are routinely cultivated and harvested, the temperature is high, and the day and night vary greatly, which is extremely unsuitable for the preservation and storage of products. Many simple methods are to find a relatively low and stable natural temperature to store agricultural products, to extend the shelf life of products, such as caves, earthen cellars, shady places, etc., these methods, can not arbitrarily control the temperature, the preservation effect is poor, the freshness period is relatively short. The final solution is to artificially create a relatively stable low temperature condition, that is, through mechanical equipment and electronic instruments, within a certain range, the temperature can be artificially controlled, and the common various cold storage is such a facility.
What is cold storage:
Cold storage generally refers to facilities that are refrigerated with various equipment and can be artificially controlled and maintained at a stable low temperature. Its basic components are: refrigeration system; electronic control device; Warehouse with certain thermal insulation performance; Outbuildings, etc. The refrigeration system mainly includes a variety of refrigeration equipment, refrigeration equipment is the heart of the cold storage, it produces the cooling capacity, to ensure the cold source supply in the warehouse. The electronic control device is the brain of the cold storage, which directs the refrigeration system to ensure the supply of cold energy. The warehouse with certain thermal insulation performance is a place for storing and preserving agricultural products, and its role is to maintain the stability of the low temperature environment, usually the thermal insulation performance is said to be heat preservation. The good thermal insulation structure of the warehouse can maximize the cooling capacity manufactured by the refrigeration equipment in the warehouse to leak outward, in turn, it is to minimize the leakage of heat outside the warehouse into the warehouse, which is also the main difference between the cold storage and the general house.
Selection and construction of cold storage types and rural origin: There are many types of cold storage in China, and there is a lack of unified standards for classification. The types commonly used according to the origin are briefly introduced as follows:
(1) According to the size of the storage capacity, there are large, medium and small. In general, the commercial large and medium-sized warehouses mentioned in the general data have a large storage capacity. According to the characteristics of the relatively small cold storage in China's production areas and the customary titles of the masses, the warehouse with a storage capacity of more than 1,000 tons can be called a large warehouse, the warehouse below 1,000 tons and more than 100 tons is called a medium-sized warehouse, and the warehouse below 100 tons is called a small warehouse. The production area is most suitable for building small cold storage of 10 tons ~ 100 tons.
(2) According to the refrigerant used in the refrigerator, it can be divided into ammonia machine cold ammonia hangar and fluorine machine cold fluorine hangar, and fluorine hangar with high degree of automation can be used to build small cold storage in rural production areas.
(3) According to the temperature of the cold storage, there are low temperature storage and high temperature storage, fruit and vegetable preservation storage is generally high temperature storage, the lowest temperature is -2 °C. The aquatic and meat preservation warehouse is a low-temperature storage with a temperature below -18 °C.
(4) According to the form of cold storage internal cooling distributor, there are pipe pipe cold storage and air cooler cold storage. Fruit and vegetable preservation generally use air cooler cold storage, commonly known as cold air storage.
(5) According to the construction mode of the warehouse, it is divided into civil cold storage, assembly cold storage and civil assembly composite cold storage. Civil cold storage is generally a sandwich wall insulation structure, covering a large area and a long construction period, and early cold storage is in this way. Prefabricated cold storage is a prefabricated insulation board assembly warehouse, its construction period is short, disassembled, but the investment is large. Civil assembly composite cold storage, the load-bearing and peripheral structure of the warehouse is the form of civil construction, and the thermal insulation structure is the form of polyurethane spray foam or polystyrene foam board assembly.
Refrigeration equipment suitable for small cold storage:
Cold storage refrigeration equipment is the heart of cold storage, very important, a cold storage operation effect of the most critical condition is refrigeration equipment. The main body of refrigeration equipment is the refrigerator, which has many kinds, according to the refrigerant is divided into ammonia machine and fluorine machine. While some fluorine machines are common models for a variety of refrigerants, advanced fluorine machines mostly use refrigerants R22 and other new refrigerants with little environmental impact. Fluorine machine is generally small in size, low noise, safe and reliable, high degree of automation, wide range of application, suitable for rural small cold storage. The combination of refrigerator and condenser and other equipment is often called a refrigeration unit, and the refrigeration unit is divided into a water-cooled unit and an air-cooled unit. Small cold storage with air-cooled unit as the preferred form, it has the advantages of simple, compact, easy to install, convenient operation, less auxiliary equipment and so on. The chiller of the refrigeration unit is the heart of the refrigeration equipment, and the common compression chiller is divided into open, semi-closed and fully closed. The hermetic compressor has small size, low noise, low power consumption, high efficiency and energy saving. It is the preferred model for small cold storage in the vast number of villages, and the air-cooled refrigeration unit mainly composed of fully enclosed compressors can be made into the form of split air conditioners and hung on the wall. At present, the better fully enclosed refrigeration compressors on the market, the quality of products imported from developed countries or Sino-foreign joint ventures is more reliable, but the price is more than 50% higher than that of domestic machines.
Benefits of building small cold storage in rural areas:
It is most suitable to build a small cold storage of 10 tons ~ 20 tons in rural production areas, and the investment in small cold storage is about 20,000 yuan ~ 40,000 yuan, which is acceptable to ordinary farmers. This small cold storage unit has small capacity, easy to control, convenient in and out of the warehouse, a product is easy to store, rapid cooling, stable temperature, less power consumption, high degree of automation, just like household air conditioners and refrigerators are as easy to manage. A number of such small cold stores are built together to form a small cold storage group, with a total capacity of hundreds of tons and thousands of tons, and its total investment is similar to that of medium and large cold storage of the same scale. But it can keep more products and varieties fresh, according to its different fresh-keeping temperature requirements, can be controlled arbitrarily, which is not easy to do in large-capacity cold storage. In short, the flexibility, operability, automation, energy-saving effect and operation effect of small cold storage groups are much better than medium and large cold storage.
