(82d) A Numerical Modelling Study of Performance Evaluation of Absorption Refrigeration Cycle (NH3-H2O)

An advanced computer simulation model using MATLAB/Simulink^® is designed to estimate the net performance of an absorption refrigeration system with the NH₃-H₂O refrigerant as a selected working fluid. In this cycle, the refrigerant (NH₃-H₂O) absorbs heat in the evaporator, vaporizes, and then is absorbed by a solution in the absorber. The vapour is compressed in the generator, which releases heat and allows the refrigerant to condense and return to the evaporator. The proposed mathematical model is developed in terms of mass and energy balance calculations, along with mass and heat transfer principles for the various parts of the cycle. This simulation model is developed to carry out the sensitivity analysis in order to investigate the impact of different operating conditions on the overall effectiveness of the cycle elements of the simulated framework. These include a generator, an absorber, an evaporator, a condenser and a liquid-liquid heat exchanger, which are modelled independently to assess their performance. The complete system is then simulated as an active absorption cycle under a range of operating conditions. In this regard, the designer will assign the temperature of each component, the heat exchanger's effectiveness, the evaporator load and the coefficient of performance. To validate the model, a comparison is performed between the results obtained from the current model and the manufacturer's data for the simulated system. This validated model includes calculations for essential parameters, such as power, area, mass flow rate and maximum power coefficient.