absorptiojäähdytyksessä

Absorptiojäähdytys, also known as absorption refrigeration, is a cooling process that utilizes a liquid coolant and a refrigerant. Unlike vapor-compression refrigeration, which relies on mechanical compressors, absorption refrigeration uses a thermal compressor. This process typically involves four main components: an evaporator, an absorber, a generator, and a condenser.

In a typical absorption cycle, a refrigerant (often ammonia or water) is evaporated in the evaporator, absorbing heat from the space to be cooled. The refrigerant vapor then enters the absorber, where it is absorbed by an absorbent solution (such as water for ammonia or lithium bromide for water). This absorption process generates heat, which must be dissipated. The enriched absorbent solution is then pumped to the generator, where heat is applied to boil off the refrigerant, separating it from the absorbent. The refrigerant vapor then travels to the condenser, where it is cooled and liquefied, releasing heat to the surroundings. The liquefied refrigerant then flows back to the evaporator, completing the cycle.

The primary advantage of absorption refrigeration is its ability to utilize waste heat or low-grade heat sources, such as solar energy or the exhaust heat from engines or industrial processes. This can lead to significant energy savings compared to conventional refrigeration methods, especially in applications where such heat sources are readily available. However, absorption systems generally have lower coefficients of performance (COP) than vapor-compression systems and can be more complex and expensive to build. They are often used in niche applications, such as large industrial cooling, where waste heat recovery is economically beneficial, or in remote locations with access to heat but limited electricity.