What is the main principle of operation of a refrigerator and an ordinary refrigeration unit?
The modern world is difficult to imagine without achievementsscientific and technical progress and the development of civilization. Thanks to scientific discoveries, people have become available to various types of energy that benefit modern humanity. One of such revolutionary discoveries was the invention of a refrigeration unit in 1910 by the French physicist Marcel Odifren.
The principle of the refrigerator is based on physicalThe phenomenon of condensation and evaporation, which is expressed in the following: the heat pump of the refrigeration unit transfers heat energy from the working chamber to the outside, where it cools and dissipates into the external environment. Cooling gas, which is freon, SF6, or ammonia, performs the reverse process, as a result of which the cold is produced.
To achieve high cold performancea large area of the heating and cooling heat exchanger is needed so that a high pressure can be created. In modern refrigeration systems, this is not always convenient, so here to achieve the necessary pressure, compressors are used that compress and pump refrigerant vapor, as a result of which not only the pressure but also the temperature of the coolant rises. Thus, the principle of the refrigeration system is based on the elementary laws of physics.
Refrigeration compressors are of the following types:
- screw;
- piston;
- centrifugal type.
The latter are the most effective and foundwide application in modern industrial refrigeration plants. In addition, in any refrigerator and freezer, a condenser is necessarily included, which is intended to convert the vapors into liquid due to a change in the ambient temperature.
In general, the principle of the refrigerator is usednot only for the creation of refrigeration facilities for various purposes, but also for freezing systems, since by adjusting the pressure in the system it is possible to obtain the necessary temperature of the internal environment of the chamber. When the compressor is operating, the refrigerant passes under high pressure through special throttle openings and enters the evaporator chamber, where as a result of a sudden decrease in pressure, the liquid instantly turns into steam. In this physical phenomenon, the refrigerant, due to its properties, takes away heat from the walls of the evaporator, resulting in gradual cooling of the inner chamber of the refrigeration system.
The principle of the refrigerator is used alreadyfor 100 years, with more and more new installations every year. One of the latest inventions in this field was the emergence of thermoelectric refrigeration units using the Peltier principle. The effect is based on the appearance of a difference in the temperature environment during the current flow, as a result of which it is possible to achieve a decrease in the temperature of the internal environment of the refrigerating space. Despite the fact that this scientist discovered this property of electric current long enough, until such time, such refrigerating chambers were not received. Usually they were used in automotive coolers, potable water coolers and refrigerator bags, however, due to the high cost of the thermoelectric cooling elements, until recently they were not quite common.
The modern operating principle of the refrigeratorwill allow to use industrial refrigerating and freezing units in the food industry, as well as in cold stores and warehouses. It is difficult to overestimate the significance of the discovery of the second law of thermodynamics, since without it it would be impossible to carry out all the activities of modern food processing plants. Thus, the principle of the refrigerator is now the basis for all modern cooling plants for both industrial and domestic purposes.
