by What are Absorption Chillers?
An absorption chiller is a device that provides chilled water for cooling and refrigeration using an absorption refrigeration cycle. In an absorption refrigeration cycle, a thermally-powered cooling effect is produced when a secondary working fluid (refrigerant) is absorbed into a high concentration solution and vaporized. The vapor is then condensed removing heat from the surrounding environment. This forms the basis of the operation of an absorption chiller.
How do Absorption Chillers Work?
Sorption use a heat source to drive the refrigeration cycle instead of mechanical power. The basic components of an Absorption Chiller include an absorber, generator, condenser, and evaporator. In the generator, a concentrated solution is heated using a heat source like natural gas, district heating, or waste heat. This causes the refrigerant vapor to be released from the solution. The refrigerant vapor rises to the condenser where it condenses removing heat. The condensed refrigerant then passes through the evaporator where it absorbs heat from the evaporator’s water circuits causing them to chill. Finally, the low-pressure refrigerant vapor from the evaporator is absorbed back into the diluted solution in the absorber, concentrating the solution and completing the cycle.
Key Components of an Absorption Chiller
Generator – This is where heat is added to separate the refrigerant vapor from the diluted absorbent solution, allowing the refrigerant to leave as a vapor. Common generators use a rich lithium bromide solution.
Absorber – This component absorbs the low-pressure refrigerant vapor back into the concentrated absorbent solution, diluting it and completing the cycle.
Condenser – In the condenser, the high-pressure refrigerant vapor is cooled and condensed to a liquid form, releasing heat to the surrounding environment.
Evaporator – Low-pressure refrigerant in liquid form enters the evaporator where it absorbs heat from the water or glycol circuits, causing chilling through the evaporation process.
Pump – A dilute solution pump circulates the diluted absorbent solution from the absorber back to the generator to start the cycle over again.
Benefits of Using Sorption
Lower Operating Costs
While sorption have higher initial capital costs compared to electric-driven compression chillers, they provide significant operating cost savings over the long run since they use low-cost heat as the primary energy input rather than electricity. Common heat sources used are natural gas, propane, waste heat recovery from engine generators, biomass boilers, and solar thermal panels. This makes sorption especially suitable for applications where low-cost waste heat is available or natural gas prices are competitive with electricity.
Reduced Electricity Usage and Peak Demand
By offloading the cooling load from electric-driven compression chillers, sorption significantly reduce electricity usage and decrease the building/facility’s monthly peak electricity demand. This provides savings on demand charges from the electricity utility. In some cases, the electricity demand reduction can even help the building avoid costly demand ratchets imposed by utilities.
Improved Sustainability Credentials
Since sorption use thermal energy instead of electricity to power the refrigeration cycle, they produce significantly lower carbon emissions compared to electrically driven chillers. This makes them an attractive sustainable cooling option, especially for LEED certified buildings aiming for improved energy efficiency and reduced emissions. Their widespread use could even help reduce grid congestion during peak cooling periods.
Allows Use of Renewable and Waste Heat Sources
A key advantage is that sorption can utilize low-grade waste heat from engine generators, industrial processes, solar thermal collectors, geothermal wells, biomass boilers and more. This waste heat source may otherwise have no economic value. By tapping into available waste heat streams, sorption improve overall system efficiency.
Applications of Sorption
Due to their flexibility to utilize various fuel sources and ability to reduce electric demand, sorption find applications in the following areas:
District Cooling Systems – Large central plants provide cooling to multiple buildings using an urban underground loop distribution system. Waste heat recovery makes sorption an ideal fit for district cooling.
Hospitals and Healthcare – Constant cooling needs year-round and heavy electricity demand charges benefit from sorption powered by on-site cogeneration systems.
Hotels – Trigeneration systems with sorption can provide efficient cooling, heating and power for hotels seeking lower utility costs.
Industrial Plants – Waste heat streams from manufacturing processes like food/beverage plants are well-suited for sorption.
Large Office Buildings – Natural gas-fired sorption substantially cut electricity usage and demand charges versus electric chillers.
In conclusion, sorption provide a cost-effective and sustainable option for cooling applications where waste heat or fuel sources other than electricity are available. With proper component selection and system design, they deliver significant energy savings and environmental benefits compared to electric compression chillers.
*Note:
1.Source: Coherent Market Insights, Public sources, Desk research
2.We have leveraged AI tools to mine information and compile it
About Author - Ravina Pandya
Ravina Pandya,a content writer, has a strong foothold in the market research industry. She specializes in writing well-researched articles from different industries, including food and beverages, information and technology, healthcare, chemicals and materials, etc. With an MBA in E-commerce, she has expertise in SEO-optimized content that resonates with industry professionals. LinkedIn Profile
