By Niyas in glossary —

Absorption chiller

In the realm of HVAC systems, understanding the various types of chillers is crucial for effective energy management and application. One such technology gaining traction is the absorption chiller, which stands out for its distinct operational principles compared to mechanical vapor compression chillers.

What is an Absorption Chiller?

Absorption chillers are advanced systems that utilize thermal and/or chemical processes to produce the refrigeration effect necessary for generating chilled water. Unlike traditional vapor compression chillers, which rely on mechanical compression of the refrigerant, absorption chillers harness heat to drive the cooling process.

How Do Absorption Chillers Work?

The principle of an absorption chiller is based on a heat-absorbing refrigerant (such as water or ammonia) and a secondary fluid that absorbs the refrigerant vapor. This process is facilitated by a refrigerant cycle that consists of four primary components: the generator, absorber, pump, and evaporator.

  • Generator: The chiller uses heat (from natural gas, steam, or hot water) to evaporate the refrigerant from a liquid to a vapor state.
  • Absorber: The refrigerant vapor is then absorbed by a secondary fluid, typically a lithium bromide solution, which cools the vapor and transforms it back into a liquid.
  • Pump: The liquid refrigerant is pumped back to the generator to restart the cycle.
  • Evaporator: The evaporation of the refrigerant absorbs heat from the environment (such as a building or process), cooling the space efficiently.

Benefits of Absorption Chillers

1. Energy-Efficiency: By utilizing thermal energy instead of electricity, absorption chillers can significantly reduce energy costs, especially in applications where waste heat is available.

2. Lower Environmental Impact: These systems often use environmentally friendly refrigerants, which contribute to reducing the carbon footprint.

3. Reliability and Longevity: Designed for durability, absorption chillers generally have fewer moving parts than mechanical chillers, leading to lower maintenance costs and longer lifespans.

Applications

Absorption chillers find their niche in various applications, particularly in large facilities where waste heat is present, such as:

Conclusion

In conclusion, absorption chillers are an efficient alternative to traditional mechanical vapor compression chillers, leveraging thermal energy to produce cooling. For HVAC professionals, understanding the operational mechanisms and benefits of absorption chillers can be integral to optimizing energy use in various applications, ultimately contributing to more sustainable building management practices.