Performance analysis and optimization of new double effect lithium bromide-water absorption chiller with series and parallel flows

In this paper the effect of some key parameters on coefficient of performance (COP) in two novel arrangements of double effect lithium bromide-water absorption chillers with series and parallel flow have been studied. The main components of these cycles are generators, absorber, condensers, evaporator and heat exchangers. The mass, concentration, and energy balance equations are used for both cycles and performances of the systems are analyzed at different conditions with the condition of no formation of lithium bromide crystal. Also, the effects of temperatures and mass flow rates of inlet vapor of generator and inlet water of absorber on evaporator cooling capacity, absorber heat transfer rate and COP are investigated. In addition, two new parameters based on mass ratio of solution splitters are defined (R-1 and R-2) and their effects on the system performance are analyzed. The results show that the series cycle at inlet vapor temperature to the high temperature generator (HTG) below 150 degrees C has higher COP than the parallel cycle. In addition, with increase of inlet vapor temperature to HTG and rise of mass flow rate of inlet water to absorber, the COP increases in both parallel and series cycles. In addition, with increase of R-1, the COP increases at first and reaches to a maximum value, and then decreases. Furthermore, the Genetic Algorithm (GA) method has been used to optimization of the system COP at series and parallel cycles. (C) 2018 Elsevier Ltd and IIR. All rights reserved.