Experimental Observation of a Small Capacity Vapor Absorption Cooling System

This paper work indicates the experimental investigation and performance evaluation of a small capacity of vapor absorption cooling system. With the development in the field of refrigeration, cooling and heat transforming systems, the vapor absorption cycle has gained renewed interest due to environmental and electricity availability problems of commonly used refrigerants in vapor compression system. The most common refrigerant-absorbent pair is water-LiBr. It is the most popular choice in absorption cooling. A small capacity vapor absorption system is first analyzed and characteristics at various points are measured. Components like absorber, evaporator, condenser and generator are designed based on capacity 2 kW. Heat exchanger sizing are made based on type of heat exchanger used. The necessary heat and mass transfer equations and appropriate equations describing the working properties are specified. The difference between absorber LiBr inlet outlet percentage ratio, the COP of the unit, variation of absorption rate with LiBr weight percentage, variation of evaporator outlet temperature are examined. The experimentally obtained cop is 0.32 which is less than the design COP 0.58. Information on designing the heat exchangers of the unit is also presented. The calculated theoretical values are then compared to experimental results derived for a small unit with nominal capacity of 2 kW. Absorber heat rejection increases with increasing absorber temperature. Evaporator heat exchanger exit temperature decreases with increasing pressure at evaporator.