It is difficult to imagine the modern world without the achievements of scientific and technological progress and the development of civilization. Thanks to scientific discoveries, different types of energy have become available to people that benefit modern humanity. One of these revolutionary discoveries was the invention of the refrigeration unit in 1910 by the French physicist Marcel Odifren.
The principle of operation of the refrigerator is based on the physical 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. The cooling gas, which is freon, SF6 or ammonia, performs the reverse process, which produces cold.
To achieve high cold productivity, a large area of the heating and cooling heat exchanger is needed so that high pressure can be created . In modern refrigeration systems this is not always convenient, therefore, compressors are used to compress and pump refrigerant vapors to achieve the required pressure, as a result of which not only pressure increases, but also the temperature of the coolant. Thus, the principle of operation of the refrigeration unit is based on the elementary laws of physics.
Refrigeration compressors come in the following types:
- screw;
- piston;
- centrifugal type.
The latter are the most effective and have been widely used in modern industrial refrigeration units. In addition, a condenser is necessarily included in any refrigerator and freezer, which is designed to turn vapors into liquids due to changes in ambient temperature.
In general, the principle of operation of the refrigerator is used not only to create refrigeration units for various purposes, but also freezing systems, since by regulating 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 evaporation chamber, where as a result of a sharp decrease in pressure, the liquid instantly turns into steam. In this physical phenomenon, the refrigerant takes away heat from the walls of the evaporator due to its properties, as a result of which the internal chamber of the refrigeration unit is gradually cooled.
The principle of operation of the refrigerator has been used for over 100 years, and more and more new installations appear every year. One of the latest inventions in this area was the emergence of thermoelectric refrigeration units that use the Peltier principle. The effect is based on the occurrence of a difference in the temperature environment during the flow of current, as a result of which it is possible to lower the temperature of the internal environment of the refrigerating space. Despite the fact that this scientist discovered this property of electric current quite a long time ago, until recently, such cooling chambers were not widely used. Usually they were used in automobile refrigerators, drinking water coolers and cooler bags, however, due to the high cost of thermoelectric cooling elements, until recently they were not quite common.
The modern principle of operation of the refrigerator will allow the use of industrial refrigeration and freezing units in the food industry, as well as in cold storage plants and product 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 plants. Thus, the principle of operation of the refrigerator is laid today at the basis of all modern cooling systems, both industrial and domestic.