Using lithium bromide aqueous solution as working medium, in which water as refrigerant, lithium bromide as absorbent. Lithium bromide is a kind of salt, white crystal, soluble in water and alcohol, non-toxic, chemically stable, will not deteriorate. The presence of air in aqueous solution of lithium bromide is highly corrosive to steel. Because water is the refrigerant and the evaporation temperature is above 0℃, the lithium bromide absorption refrigerating machine can only be used for air conditioning equipment and cold water used in the production process. This kind of refrigerating machine can use low-pressure steam or hot water above 75℃ as heat source, so it plays an important role in the utilization of waste gas, waste heat, solar energy and low-temperature thermal energy.
Because the boiling point of the solution of lithium bromide is very high, it is very difficult to volatilize, so the vapor on the surface of the saturated solution of lithium bromide can be considered as pure water vapor. At a certain temperature, the saturated partial pressure of water vapor on the surface of lithium bromide aqueous solution is less than that of pure water. And the higher the concentration, the smaller the vapor saturation pressure on the surface. Therefore, under the same temperature conditions, the greater the concentration of lithium bromide water solution, the stronger its ability to absorb water. This is why lithium bromide is usually used as absorbent and water as refrigerant.
