A comparative study of the performance characteristics of double-effect absorption refrigeration systems

摘要

Three classes of double-effect lithium bromide-water absorption refrigeration systems (series, parallel and reverse parallel) with identical refrigeration capacities are studied and compared thermodynamically. In order to simulate the performances of the systems, a new set of computationally efficient formulations is used for thermodynamic properties of Li-Br solutions at equilibrium. The simulation results are used to examine the influence of various operating parameters on the first and second law performance characteristics of the systems. In addition, the dependences are investigated of system performance on the effectivenesses of the solution heat exchangers, the pressure drops between the evaporator and the absorber and between the low-pressure generator and the condenser, and the low-grade heat externally supplied to the low-pressure generator. The results reveal the advantages and disadvantages of different configurations of double-effect lithium bromide-water absorption refrigeration systems, and are expected to be useful in the design and control of such systems.