SOLUTION

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 a Lithium bromide absorption refrigeration system the refrigeration is water and lithium bromide is the absorber.
• 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 to 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 vapors 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 vapors returning from the evaporator so the cycle can be repeated.