Theoretical and experimental investigation on the absorption refrigeration systems

Abstract EN

In the present work, theoretical model is developed to study the single-effect absorption refrigeration cycle from the thermodynamic point of view for lithium bromide-water pair and lithium chloride-water pair.

The effect of different operating temperatures on the coefficient of performance (COP) and flow ratio (FR) (the weak solution mass flow rate with reference to the refrigerant mass flow rate) are investigated.

The generation process in an absorption refrigeration cycle using lithium chloride-water solution as the working pair is experimentally studied.

From the theoretical study, it is found that the COP increases with an increase in generation temperature until a certain value, then it decreases slightly.

The COP increases with an increase in evaporator temperature and decrease in condenser or absorber temperatures.

The rate of decrease in FR is higher at higher condenser and absorber temperatures.

The data obtained for lithium bromide-water pair is compared with lithium chloride-water pair It is found that the COP is higher for lithium chloride-water pair than that for lithium bromide-water pair and the FR is lower for the lithium chloride-water pair.

The experimental results are plotted to illustrate the effect of generation temperature on the coefficient of performance, flow ratio and output variables.

Also, the effect of the inlet solution temperature, inlet solution flow rate and generator pressure on the generated water vapor is discussed.

A minimum generation temperature must be chosen to boil off the water from the lithium chloride-water solution.

From the measured data a maximum coefficient of performance of 0.812 can be obtained for a single stage system.