absorbtionjäähdytys

Absorbtionjäähdytys is a refrigeration technology that uses a heat source to drive a cooling cycle, rather than mechanical work. The system consists of a refrigerant that evaporates at low pressure, absorbing heat and producing a cold effect, and an absorbent that absorbs the refrigerant and releases it at higher pressure after a heat input. Common refrigerant‑absorbent pairs include ammonia‑water and lithium bromide‑water; the choice depends on the desired temperature range and the available heat source.

In operation, the low‑pressure refrigerant vapor is condensed in a heat exchanger by the heated absorbent. The hot absorbent carries the refrigerant vapor to a generator where the heat supply drives the separation of refrigerant and absorbent. The pure refrigerant then evaporates in an evaporator, providing cooling to the conditioned space, while the absorbed liquid refills the absorber, completing the cycle. Because the drive energy is heat, absorbtionjäähdytys can utilize waste heat from industrial processes, solar thermal collectors, or low‑grade geothermal sources, making it attractive for environmentally friendly and energy‑efficient applications.

Historically, absorption refrigeration was first patented in the 19th century and saw widespread use in large ships and early industrial plants. Modern systems, especially those employing ammonia‑water or lithium bromide‑water loops, are found in commercial air conditioning units, cold storage facilities, and in rail freight where LNG or natural gas is available as a heat source. Advantages of the technology include lower electrical consumption, fewer moving parts, and the ability to run on low‑grade heat. Disadvantages are larger equipment footprints, higher initial costs, and less efficient performance at extremely low temperatures, where compressor‑based systems are more economical.