What two mixtures are commonly used in absorption systems?

Lithium bromide and water are commonly used in absorption refrigeration systems due to their effectiveness in heat absorption and transfer. This mixture takes advantage of the thermodynamic properties of lithium bromide, which has a strong affinity for water, allowing it to absorb moisture from the refrigerant vapor.

In these systems, the lithium bromide solution acts as the absorbent, efficiently capturing water vapor that has evaporated from the refrigerant. The process of absorption breaks down into several stages, including the generation of vapor, the absorption of that vapor by the lithium bromide solution, and the subsequent release of heat. This cycle allows for a continuous operation in cooling applications.

Other mixtures, such as hydrochloric acid and water or ammonium sulfate and water, are not commonly used in refrigeration applications, as they do not possess the appropriate properties needed for efficient thermodynamic cycles in absorption systems. Glycol mixed with water might be relevant in other contexts such as freeze protection or as a heat transfer fluid, but it is not typically utilized in absorption systems for refrigeration.