When water – Lithium Bromide is used in a vapour absorption refrigeration system, then

When water – Lithium Bromide is used in a vapour absorption refrigeration system, then Correct Answer water is the refrigerant.

Concept:

In the vapour absorption system, the water is used as the refrigerant while lithium bromide (Li Br) is used as the absorbent.

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Basic Vapour Absorption Refrigeration System

• The basic absorption cycle employs two fluids, the absorbate or refrigerant, and the absorbent
• The most common fluids are Water/Ammonia as the refrigerant and lithium bromide/ water as the absorbent
• These fluids are separated and recombined in the absorption cycle
  In the absorption cycle, the low-pressure refrigerant vapour is absorbed into the absorbent releasing a large amount of heat (Absorber pressure is equal to evaporator pressure)
• The liquid refrigerant/absorbent solution is pumped to a high-operating pressure generator using significantly less electricity than that for compressing the refrigerant for an electric chiller
• Heat is added at the high-pressure generator from a gas burner, steam, hot water or hot gases
• The added heat causes the refrigerant to desorb from the absorbent and vaporize
• The vapours flow to a condenser, where heat is rejected and condense to a high-pressure liquid
• The liquid is then throttled through an expansion valve to the lower pressure in the evaporator where it evaporates by absorbing heat and provides useful cooling
• The remaining liquid absorbent, in the generator, passes through a valve, where its pressure is reduced, and then is recombined with the low-pressure refrigerant vapours returning from the evaporator so the cycle can be repeated