We are glad that Cadley Chiller answers for you: Cold storage refers to a facility that is refrigerated with various equipment, can be artificially controlled and maintained at a stable low temperature.
Refrigeration systems, control devices, insulated warehouses, ancillary buildings, etc. are the basic components of cold storage. The refrigeration system of the cold storage mainly includes the cold storage unit, which is the core of the cold storage to ensure the cold source supply in the cold storage room.
The control device is the brain of the cold store, directing the refrigeration system to ensure the supply of cold energy. Cold storage warehouse, is the place to store and preserve agricultural products, its role is to maintain the stability of the low temperature environment, usually the thermal insulation performance is said to be insulation.
The good thermal insulation structure of the cold storage room can maximize the cold capacity manufactured by the cold storage unit in the cold storage to the outside less leakage, conversely, it is to minimize the leakage of heat outside the cold storage into the cold storage, which is also the main difference between the cold storage and the general house. Cold storage is mainly used for food, medicine, mechanical freezing processing and refrigeration, it through artificial refrigeration, so that the indoor to maintain a certain low temperature.
The walls, floors and flat roofs of the cold storage building are covered with a certain thickness of thermal insulation materials to reduce the heat transfer outside the cold storage. In order to reduce the absorption of solar radiation energy, the surface of the outer wall of the cold storage is generally painted white or light color, so the cold storage building is different from the general industrial and civil buildings, it has its own unique structure.
Working principle of mechanical cold storage Mechanical cold storage This method of storing fruits is in a good thermal insulation building, equipped with mechanical cold storage units, and according to the requirements of fruit varieties for storage temperature, humidity and ventilation, the cold storage system is artificially adjusted and controlled, so the storage time is longer and the effect is better. A. The principle of mechanical cold storage refrigeration.
Mechanical cold storage is the use of a liquid (refrigerant) with a very low gasification temperature to evaporate into gas under low pressure, thereby absorbing heat and achieving the purpose of cooling. In addition to low boiling point, refrigerants for cold storage are also required to be harmless to human organs, have no corrosive effect on metals, no risk of combustion and explosion, do not react chemically with lubricants, and should also have good heat absorption performance, evaporation and heat absorption, low pressure in high-pressure condensing systems, low viscosity and cheap price.
Types and properties of commonly used refrigerants in cold storage Boiling point(°C) Critical temperature(°C) Heat of vaporization (liters/g) Ammonia (NH3) -35.5 132.4 301.6*4.18 Carbon dioxide (CO2) -78.2 31.1 55.0*4.18 Sulfur dioxide (SO2) -10.0 157.2 91.3*4.18 Chloromethane (CH2CL) -23.7 143.1 98.8*4.18 Freon (CCL2 F2) -30.0 111.5 37.2*1.18 Among the refrigerants above cold storage, ammonia and Freon refrigeration effect are the most common. The main engine of the cold storage - refrigeration refrigerator with the working principle of cold storage refrigerant gasification and heat absorption is two types: compression type and absorption type.
The compression type is more used. The main structures of cold storage compression refrigeration refrigerator are; Compressor, condenser, evaporation pipe and air cooler parts.
B. Cold storage storage period management. The suitable temperature for fruit refrigeration varies from variety to variety, and most late-ripening varieties should be stored in a cold storage of -1-0 °C.
The humidity of the cold storage should be 90%. After the fruit is harvested, it must be cooled as soon as possible (pre-cooled to about 0 °C), and it is best to enter the cold storage within 1-2 days after harvesting.
Because the harvested fruits are delayed for 1 day at a temperature of 21 °C, the storage life of 10-20 days will be reduced at 0 °C, so the fruits that have been graded and selected after harvest should be quickly cooled to -1-0 °C within 3-5 days after entering the cold storage. The management of fruits stored in cold storage is mainly to regulate and control the temperature, humidity and gas composition of the cold storage environment.
Temperature regulation is based on the temperature requirements of different varieties and different periods, and the evaporation rate of the cold storage refrigerant is controlled to control the cold storage temperature. Cold storage often due to frost of the cooling pipe system, and hinder the conduction of heat, affect the cooling effect, and due to frosting, the humidity in the cold storage is too low, so it should be regularly heated and defrosted, and timely wet or spray to adjust the humidity of the cold storage.
The ventilation of the cold storage should be carried out at night, if the carbon dioxide accumulation in the cold storage is too much, an air purifier can be installed, and 7% caustic soda can also be absorbed.
