LiBrSysteme

LiBrSysteme, short for lithium bromide systems, denote a class of thermally driven cooling and humidity control systems that use lithium bromide as the absorbent in a water-refrigerant cycle. The LiBr–H2O pair is the most common, in which water acts as the refrigerant and LiBr absorbs it.

In a typical LiBr system, heat input at the generator causes desorption of water from the LiBr solution; the water vapor is condensed and then evaporated in the evaporator; the resulting vapor is absorbed by the LiBr solution in the absorber; the enriched solution returns to the generator via a pump and heat exchanger.

Design variants include single-effect and double-effect configurations; double-effect uses the heat from the absorber or generator to drive another desorption step, improving COP. Efficiency depends on temperatures, the quality of absorbent, and crystallization control.

Materials: LiBr is highly hygroscopic and corrosive to many metals; systems require corrosion-resistant materials (stainless steel, nickel, special coatings) and anti-crystallization controls; crystallization can occur if concentration or temperatures fall too low, leading to blockages.

Applications: energy-efficient cooling for large buildings, industrial process cooling, district cooling, and solar-thermal integration. LiBr systems offer low environmental impact due to zero ozone depletion potential and low global warming potential relative to some refrigerants; but they require reliable heat sources and maintenance.

Desiccant variants use LiBr solutions for humidity control in HVAC, offering adiabatic dehumidification; regeneration uses heat and closed-loop cycles.