Air Conditioning process can divide in to four sections such as Compressor, Condenser, Expansion Valve and Evaporator.This air conditioning process is cycle and it can describe as simple as following image. There is a high pressure and low pressure side of the air condition and blue color show the cooling side and red color show the heated high pressure sides.Followng are the main components of Air Conditioning Process.
The compressor which pumps the refrigerant around the system is the heart of the air conditioner. Before the compressor, the refrigerant is a gas at low pressure. Because of the compressor, the gas becomes high pressure, gets heated and flows towards the condenser.
At the condenser, the high temperature, high pressure gas releases its heat to the outdoor air and becomes sub cooled high pressure liquid.
The high pressure liquid goes through the expansion valve, which reduces the pressure, and thus temperature goes below the temperature of the refrigerated space. This results in cold, low pressure refrigerant liquid.
Main Air Conditioning Process cycle
There are several heat transfer loops in a refrigeration system as shown in Figure 2. Thermal energy moves from left to right as it is extracted from the space and expelled into the outdoors through five loops of heat transfer.
Indoor air loop:
In the left loop, indoor air is driven by the supply air fan through a cooling coil, where it transfers its heat to chilled water. The cool air then cools the building space.
Chilled water loop:
Driven by the chilled water pump, water returns from the cooling coil to the chiller’ s evaporator to be re-cooled.
Using a phase-change refrigerant, the chiller’ s compressor pumps heat from the chilled water to the condenser water.
Condenser water loop:
Water absorbs heat from the chiller’ s condenser, and the condenser water pump sends it to the cooling tower.
Cooling tower loop:
The cooling tower’ s fan drives air across an open flow of the hot condenser water, transferring the heat to the outdoors.
Type of refrigerants
A variety of refrigerants are used in vapor compression systems. The required cooling
temperature largely determines the choice of fluid. Commonly used refrigerants are in the family of chlorinated fluorocarbons (CFCs, also called Freons): R -11, R-12, R-21, R-22 and R-502. Every Refrigent Gases has separate color to identify.
The choice of refrigerant and the required cooling temperature and load determine the choice of compressor, as well as the design of the condenser, evaporator, and other auxiliaries.
Additional factors such as ease of maintenance, physical space requirements and availability of utilities for auxiliaries (water, power, etc.) also influence component selection.
We are planing to discuss more on regarding the Air Conditioning Process and the electrical details related to