What refrigerant do absorption chillers use?
lithium bromide
Absorption chillers can be used for both heating and cooling purposes simultaneously, by using the process cooling water from the absorber and the condenser. The most efficient modern absorption cycle chillers use water as the refrigerant and a solution of lithium bromide (LiBr) as the absorbent.
How is COP of absorption chiller calculated?
The COP can be thought of as a sort of index of the efficiency of the machine. It is calculated by dividing the cooling output by the 299 Page 2 required heat input. For example, a 500-ton absorption chiller operating at a COP of 0.70 would require: (500 x 12,000 Btu/h) divided by 0.70 = 8,571,429 Btu/h heat input.
How efficient are absorption chillers?
Looking at Graph 1, all three types of absorption chillers are most efficient at 50% part load with the single-effect indirect-fired chiller having a 9.4% increase in efficiency; the double-effect direct-fired chiller having a 10% increase in efficiency; and the double-effect indirect-fired chiller having a 16.7% …
How do absorption chillers work?
In short, the absorption chiller chills water via sudden change of pressure. When the water heats up in the generator, the air pressure is high. Water releases the heat and becomes vapor. Then, as it goes through the cooling tower, the vapor cools down in a low-pressure environment and becomes water again.
What medium is used for cooling in an absorption refrigerant cycle?
Cooling can be accomplished from geothermal energy using lithium bromide or ammonia absorption refrigeration systems. The lithium bromide system is the most common because it uses water as the refrigerant.
Is LiBr a refrigerant?
The lithium bromide- water (LiBr-H2O) absorption system mainly constitutes evaporator, absorber, generator, condenser, solution pump, storage tank and expansion valve [1]. When powered by flat plate collector, the water is taken as refrigerant and Lithium Bromide (LiBr) as absorbent.
Why lithium bromide is used in absorption chiller?
Lithium Bromide (LiBr) has the property to absorb water (Refrigerant) due to its chemical affinity. It is directly proportional to concentration and inversely proportional to its temperature. Diluted LiBr loses its capacity to absorb water vapour. Thus, needs to be re-concentrated using a Heat Source.
What is double effect absorption chiller?
Double-Effect Absorption Chillers A double-effect absorption chiller has the same basic components as single-effect, but also includes an additional generator, heat exchanger and pump. Within this kind of chiller there are two cycles: a main cycle, and an auxiliary cycle.
How much does absorption chiller cost?
Installed costs range from $1,800 to $6,000 per ton for the three single stage systems, and from $1,600 to $3,300 per ton for the four two stage chillers.
Is lithium bromide a refrigerant?
In a water-lithium bromide vapor absorption refrigeration system, water is used as the refrigerant while lithium bromide (Li Br) is used as the absorbent. In the absorber, the lithium bromide absorbs the water refrigerant, creating a solution of water and lithium bromide.