Today, the life of absorption chillers in Iran has reached to more than half a century and it is used as one of the most suitable cooling equipment in the installation industries. Due to its reduced power consumption and lack of vibration and noise and its possibility to install it in any industrial and non-industrial environment, hence the project owners consider this cooling system as a proper equipment to select.

In adsorption chillers some chemicals are used as adsorbents for example in Ammonia chillers absorption element would be Ammonia and Lithium absorption chillers, an inorganic salt Lithium bromide is used as the adsorbent of steam in Lithium absorption chillers.

Physical Structure of Absorption Chillers:

Absorption chillers consist of evaporator and absorber units in its shell and its main shell and also condenser and generator units in the shell and the smaller shell and finally consist of heat exchanger, side systems such as Purge system to absorb and discharge non-condensation gases – guard cycle system to control the volume of water and the concentration of LiBr in this device and also transmission and heat transfer pipelines. Of course in some types of absorbent chillers the four main units are compacted in a shell and sometimes in others, there is no Purge system and non-condoning gases at different intervals are exhausted from the device by the vacuum pump.

Chemical Structure of Absorption Chillers:

In this type of chillers there are four fluid flows that are thermally related:

1. The ordinary water which flows in the fan coil system and the evaporator unit.
2. Another water flow which goes through the cooling tower system, absorber and condenser units.
3. The distilled water contained within the chiller-packed system which causes the concentration and dilution of LiBr (Carries heat from evaporator to absorber)
4. LiBr which is an inorganic salt and acts as an absorbent in the system, absorbs warm water steam and transmits it.

Absorption Chiller Performance:

When the fan coil water transfers its chill to the room and absorbs the existing heat this is transferred to the chiller by pump. Then the heat reaching the chiller enters the distilled water inside the machine and causes the water to become water vapor. These warm vapors are carried by LiBr inside the chiller and then this connects itself to the water from the cooling tower to the chiller and transfers its heat to the water tower, then this heat is pumped by tower water to the cooling tower and finally the heat is dissipated outside.