Absorptsioonjahutus

Absorptsioonjahutus is a refrigeration process that uses a heat source, rather than a mechanical compressor, to provide the necessary energy for cooling. It relies on the principle of absorption and desorption of a refrigerant by an absorbent fluid. The most common working pair is water as the refrigerant and lithium bromide as the absorbent, or ammonia as the refrigerant and water as the absorbent.

The cycle typically involves an evaporator, an absorber, a generator, and a condenser. In the evaporator, the refrigerant evaporates at low pressure, absorbing heat from the space to be cooled, thus producing the desired cooling effect. The refrigerant vapor then moves to the absorber, where it is absorbed by the absorbent solution. This absorption process is exothermic, releasing some heat. The resulting rich solution is then pumped to the generator, where it is heated by an external heat source. This heat causes the refrigerant to desorb from the absorbent, becoming a high-pressure vapor. The vapor then moves to the condenser, where it is cooled and condensed back into a liquid. Finally, the liquid refrigerant is returned to the evaporator, completing the cycle.

Absorptsioonjahutus systems are often employed when waste heat is readily available, such as from industrial processes, solar thermal collectors, or combined heat and power (CHP) systems. They are also advantageous in situations where electricity is expensive or unreliable. The cooling capacity of these systems can range from a few kilowatts to several megawatts. While generally less efficient in terms of energy conversion compared to vapor-compression refrigeration, their ability to utilize waste heat makes them an environmentally friendly and economically viable option in specific applications.