Fridge types and types, its structure.
A refrigerator is an apparatus for cooling items placed in his cell. It is used for perishable foods and other things that require storage at low temperature.
A refrigerator is an apparatus for cooling items placed in his cell. It is used for perishable foods and other things that require storage at low temperature. The cooling function is provided by a refrigeration machine, through which heat is removed from the camera outside of the refrigerator.
The principle of operation of refrigerators can vary. Based on that model are divided into:
– equipped with vortex coolers.
Compression refrigerators are the most common.
In the market you can find different types of refrigerators — household, commercial, industrial. The first is designed for use at home, the second have higher ratios of cooling power and are used in public places such as restaurants, shops, etc. Industrial refrigerators are used in factories, plants, they may represent a separate room or a big installation for the storage of large volumes of products.
In the medium temperature cold rooms the temperature does not drop below zero, and in the low temperature, or freezing, it ranges from -18 to -21 OS. Last may enter into the design of refrigerated cabinets or issued as separate devices that perform the sole function of the freeze.
The operation of the refrigerating apparatus based on the second law of thermodynamics. The refrigerant is so-called reverse Carnot cycle (a refrigerant or refrigerant – the working fluid takes heat from the cooled object and transmitting it to the cooling medium). The main role in heat transfer is played by the changing thermodynamic state of the refrigerant phase transitions — evaporation and condensation. To operate the cooling function is, in fact, enough of a Carnot cycle, but in order to achieve a high cooling power, you need to use compressor to create significant pressure or heat exchangers heating and cooling must have a significant heat exchange area.
Compression refrigerator consists of the following main elements:
compressor, the purpose of which is to ensure the required pressure difference,
– evaporator performs the function of intake of heat from the inner chamber,
capacitor, outputting heat from the refrigerating apparatus,
– thermostatic expansion valve performs the throttling of the refrigerant and thereby providing a pressure difference,
– the refrigerant, transferring heat from the evaporator to the condenser.
The refrigerant in a gaseous state is sucked from the evaporator to the compressor, which produces the contraction and passes it to the condenser. It’s condensation, during which it gives off heat to the external environment. The resulting fluid enters the capillary.
Turned into a liquid refrigerant under pressure is passed into the evaporator passing through the expansion valve or capillary. Here it evaporates, aided by significant pressure drop. The liquid absorbs heat from the inside walls of the evaporator, causing the cooling chamber is cooled.
Domestic models are equipped with hermetic reciprocating compressors with a motor. These compressors are protected from leakage due to the location of the motor within the housing. In addition, in models for use in the home, usually installed condensers finned-tube type. Cooling in most cases is carried out in a natural way, in particular by thermal radiation and convection. In refrigerators high-performance and industrial models feature a forced cooling system of the condenser.
As a rule, in the domestic options are set lototrone evaporators of aluminium. They have internal channels through which the refrigerant. In the refrigerating chamber evaporator is located on the rear panel, and the freezer often he acts as the camera body.
The refrigerator has double walls, between which are insulating materials – mineral wool, polyurethane or polystyrene foam. Of how well insulated its body depends on the amount of energy consumed.
The function performs insulation and door seal, which fills the gap between it and the housing and prevents the penetration of warm air into the chamber. Feature of seals in modern models is the magnetic insert, through which the door closes.
Air circulation in the chamber can occur naturally or artificially organized. An example of an artificial system is the technology of No Frost — in this case, the evaporator and the main camera are located separately from each other, and moving the air between them is carried out by means of a fan. This hinders the emergence of a layer of frost on the evaporator, since the air is pre-dried, in addition, the melting of the snow layer is not required to raise the temperature in the chamber. There are models of refrigerators that allow you to control the level of temperature and humidity; some also are provided special defrosting system to avoid buildup of frost.
The thermostat in domestic refrigerators is it to cycle on and off. The correct engine start adjustable starting and protective relays. Refrigerators equipped with sensors to open doors that automatically turn on the light in the chamber when it is otvorenie; more advanced models are equipped with an alarm that is triggered when long finding the door open. Today, you can find refrigerators with Internet access, with integrated in the body computer.
Refrigerators may have different layout. Consider what its variations can be found on the market.
When the “European” version, the freezer is located below the refrigeration chamber.
The “American” variant is the parallel arrangement of refrigerator and freezer placed side by side and have the same height. These refrigerators can have a volume of more than 700 HP
In the case of “Asian” layout freezer is located above the cooling chamber.
Vertical refrigeration Cabinet, not having a freezing chamber and has a glass door, typically used for storing beverages.
Horizontal refrigerator, also called a refrigerated chest, often represents the freezer. Its design helps to reduce leakage of cold when the cover is opened. The main sphere of its application — trade.
In order for the refrigerator served as long as possible, you need to follow certain rules of operation. In the model without autoactive is not recommended to place hot products, because they emit vapor, resulting in the vaporizer quickly formed snow. Thus irrespective of, whether the refrigerator is equipped with system of automatic defrosting, efficiency is reduced, it starts to consume more energy.
Refrigerators without automatic defrost is necessary to regularly defrost the unit disconnected from the network until the complete disappearance of the layer of frost. Disabling should lay out all the products and open the door.
Regular washing and airing of the Cabinet is required — this applies to models with autoactivation, and without.
Models with natural convection, the temperature varies on different shelves, which should be considered when placing products. Modern advanced models are equipped with various cameras specially designed for storing certain kinds of products — they are kept at a temperature regimethat is optimal in each case.
Products should be stored in closed containers — odors easily eats into the chamber wall and the gasket and get rid of them is difficult, despite the abundance of advice on the Internet. It is necessary to monitor the timely removal of spoiled food. Certain types of products readily absorb odors, and they should be accommodated separately; these include dairy products, including butter, cheese, etc. to Prevent penetration of foreign odors and allows for the use of sealed food containers.
According to European statistics, one person is enough refrigerator with a volume of 150 l For a group not exceeding four people, the best a volume of about 280 liters, but with a larger number of people are advised to choose a larger model.
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