How single-effect absorption chiller works?
The single-effect absorption cycle uses water as the refrigerant and lithium bromide as the absorbent.
It is the strong affinity that these two substances have for one another that makes the cycle work.
The entire process occurs in almost a complete vacuum.
A dilute lithium bromide solution is collected at the bottom of the absorber shell.
From here, a hermetic solution pump moves the solution through a shell and tube heat exchanger for preheating.
After exiting the heat exchanger, the dilute solution moves into the upper shell.
The solution surrounds a bundle of tubes that carry either steam or hot water.
The steam or hot water transfers heat into the pool of dilute lithium bromide solution.
Hence the solution boils, sending refrigerant vapor upward into the condenser and leaving behind concentrated lithium bromide.
The concentrated lithium bromide solution moves down to the heat exchanger.
Where it is cooled by the weak solution being pumped up to the generator.
The refrigerant vapor migrates through mist eliminators to the condenser tube bundle.
A refrigerant vapor condenses on the tubes.
The heat is removed by the cooling water which moves through the inside of the tubes.
As the refrigerant condenses, it collects in a trough at the bottom of the condenser.
The refrigerant liquid moves from the condenser in the upper shell down to the evaporator in the lower shell.
Then after it is sprayed over the evaporator tube bundle.
Due to the extreme vacuum of the lower shell, the refrigerant liquid boils at approximately 39°F (3.9°C).
This will create the refrigerant effect. (This vacuum is created by hygroscopic action – the strong affinity lithium bromide has for water – in the Absorber directly below.)
As the refrigerant vapor migrates to the absorber from the evaporator.
The strong lithium bromide solution from the generator is sprayed over the top of the absorber tube bundle.
The strong lithium bromide solution actually pulls the refrigerant vapor into the solution, creating an extreme vacuum in the evaporator.
The absorption of the refrigerant vapor into the lithium bromide solution also generates heat which is removed by the cooling water.
The now dilute lithium bromide solution collects in the bottom of the lower shell, where it flows down to the solution pump.
The chilling cycle is now completed and the process begins once again.