Absorption Chiller

An absorption chiller is a thermal-driven cooling system that uses a binary fluid pair, typically water as refrigerant and lithium bromide as absorbent, to generate chilled water via a thermo-chemical cycle instead of mechanical compression. It operates by flashing water under vacuum to absorb heat, dissolving vapor in the absorbent, and using a heat source like steam or hot water to regenerate the solution.

On the shop floor, absorption chillers are installed in facilities with waste heat from cogeneration or combined heat and power plants, high electricity costs, or unreliable grid power to provide large-tonnage HVAC cooling without electric compressors. They are driven by low-grade heat (single-effect) or high-grade heat (double-effect). Maintenance focuses on chemistry control of lithium bromide concentration and corrosion inhibitors, vacuum integrity, and heat transfer surface cleanliness. In CMMS systems like ServiceGrid, they are tracked as critical thermal assets with tasks for lithium bromide analysis 1-2 times per year, corrosion inhibitor topping, and vacuum monitoring.

• ⚠️Vacuum loss due to refrigerant leaks or non-condensable gas accumulation, causing crystallization of lithium bromide and standalone shutdown.
• ⚠️Crystallization from improper solution concentration or temperature swings, blocking flow paths and requiring system purge or reheat.
• ⚠️Corrosion of internal components like heat exchangers and pumps due to degraded corrosion inhibitors in lithium bromide, leading to premature metal failure.