Absorption cycle systems water is the refrigerant, and ___________ is used as the absorber.

Absorption cycle systems water is the refrigerant, and ___________ is used as the absorber.

• A. Ammonia
• B. Lithium bromide
• C. Water
• D. Freon

Answer: (B)

In absorption cooling, the absorber must attract and hold the refrigerant vapor. When water is used as the refrigerant, lithium bromide is the standard absorber because it is highly hygroscopic (it readily absorbs water) and is nonvolatile, so it stays as a liquid while taking up water vapor from the evaporator. The generator heats the LiBr–water solution to release water vapor, which then condenses and returns to the evaporator to continue cooling, while the LiBr solution recirculates back to the absorber to absorb more water. Freon isn’t used in absorption cycles, and ammonia would use water as the absorbent in its own ammonia–water system, not lithium bromide. Water itself isn’t the absorber in this setup, so lithium bromide is the correct choice.

In absorption cooling, the absorber must attract and hold the refrigerant vapor. When water is used as the refrigerant, lithium bromide is the standard absorber because it is highly hygroscopic (it readily absorbs water) and is nonvolatile, so it stays as a liquid while taking up water vapor from the evaporator. The generator heats the LiBr–water solution to release water vapor, which then condenses and returns to the evaporator to continue cooling, while the LiBr solution recirculates back to the absorber to absorb more water. Freon isn’t used in absorption cycles, and ammonia would use water as the absorbent in its own ammonia–water system, not lithium bromide. Water itself isn’t the absorber in this setup, so lithium bromide is the correct choice.