T-x diagrams for refrigerant
This Temperature/Enthalpy (T-H) is similar to the T-x diagram for water, and is used for definitions of terms used in refrigeration. Understanding of the terms we will post on this scheme, however, will be easier if you remember, the difference between the heating water's example and heat transfer during the mechanical refrigeration system.
- Instead of water in a saucepan, we refrigerant inside the heat exchange coil, called the evaporator.
- Instead of fire, to heat the water, we have a relatively warm air in the room heating cold refrigerant in the evaporator tubes.
- Instead of water boiling in pairs 212F, we refrigerant BOILING point of about 40F.
- In addition, instead of cooling pair, so that it is condensed into water, we refrigerant rejecting heat and condense into a liquid inside of another heat exchange coil called a capacitor, which we will discuss in a moment.
As shown on the diagram, as a rule, refrigerant enters the evaporator, as SUPERCOOLED liquid.
As in the case of water, this means that it is below its saturation temperature of 212F sea level, and therefore sub-cooled. Moreover, even 160F water is considered as "hypothermia" in refrigeration terminology.
As heat is added to the refrigerant, it is saturated with heat SATURATION TEMPERATURE and called SATURATED LIQUID. In this moment, is as intense heat in the capacity of liquid may be without beginning it changes into a gas. (Refrigerant 22 40F 69 PSIG saturated liquid.) Add more heat, and this is starting to change gas, which is called the SATURATED VAPORS. This vapor is as rich warm gas can be without its growth above the saturation temperature. Refrigerated heated above the saturation temperature is called the SUPERHEATED GAS. For example, a pair at a temperature of 220F was superheated 8F. Refrigerant 22 55F 69 PSIG was superheated 15F.
And Vice versa, as the heat is removed from the refrigerant, we see the process, we need to move from right to left on the schedule, the first cooling refrigerant, then condensation of vapor into liquid), and, finally, hypothermia. Since the mechanical cooling system from sealed air outside the system of heat transfer process is reversible. It was wrong for the pan with water, because it was under open air in the room. The water that is boiled off, combined with chemically air of the room, and simply cannot condense into liquid when water temperature has fallen below the boiling point.
In the process of condensation of the refrigerant refrigerant enters the condenser, as superheated gas and is the first de-superheated that reduces it to the saturation temperature (120F). Finally, the liquid refrigerant begins to subcool while still in the condenser.
The refrigerant in any condition can be found in the system at any time: supercooled liquids, saturated liquid, saturated liquid/vapor mixture, vapour, or superheated gas. All present...
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Refrigeration 
