Direct expansion air conditioning system (DX)
Introduction
The so-called refrigeration systems or refrigeration systems correspond to mechanical arrangements that use the thermodynamic properties of matter to transfer thermal energy in the form of heat between two or more sources, as required. They are designed primarily to reduce the temperature of the product stored in cold rooms or refrigeration chambers, which may contain a variety of foods or chemical compounds, according to specifications.
It is worth mentioning the radical difference between a refrigeration system and a refrigeration circuit, the latter being a mere arrangement to reduce the temperature, which is defined as a "concept", since its design (open, semi-open, closed), fluid (air, water, even refrigerant gas), flow (only cold or "heat pump"), etc. varies depending on the application. These vary from the classic cooling of internal combustion engines by means of water to the water cooling used in computer cooling. Refrigeration systems tend to be much more complex than a refrigeration circuit and that is why they are presented separately.
In the final study and design of these refrigeration systems, various sciences are applied, such as chemistry, to the properties and composition of the refrigerants; thermodynamics, in the study of the properties of matter and its internal energy; heat transfer, in the study of heat exchangers and technical solutions; as well as mechanical engineering, in the study of gas compressors "Compressor (machine)" to achieve the required compression work. These disciplines have been mentioned, leaving aside electricity, from traditional knowledge in three-phase currents for powering the equipment, to relatively advanced knowledge in automation and PLC, for the automatic control that they require when operating in a refrigeration plant.
Refrigeration systems differ from each other according to their refrigerant injection method and constructive configuration, both conditioned by their design parameters. In this way, and by making an adequate balance of masses and energies, it is possible to find the appropriate solution to any refrigeration request.