Performance analysis of double effect solar absorption cooling system with different schemes of hot/cold auxiliary integration and parallel-serial arrangement of solar field

Abstract

Energy consumption of heating and/or cooling auxiliary devices in solar sorption cooling systems is one of the major factors of reduction in primary energy savings. This work simulates and analyzes the dynamic operation of a solar thermal double effect absorption cooling system for three strategies of employing hot and/or cold auxiliary devices and the influence of instituting the entire solar collector field in series versus parallel arrangement. An auxiliary heater is installed in the hot storage to absorption chiller loop in configuration-1 (C-1) to maintain the desired generator temperature. An auxiliary cooler is employed in configuration-2 (C-2) to furnish the cooling load in conjunction with an absorption chiller energized only by the evacuated tube solar collector (ETC). In configuration-3 (C-3) both auxiliary heater in the storage to chiller loop and auxiliary cooler in the chiller to load loop are modeled for three percentage contributions of the required cooling load by the double effect absorption and water-cooled vapor compression chiller i.e., 50-50 (C-3a), 70–30 (C-3b), and 30–70 (C-3c), respectively. Simulation results demonstrated that at lower collector areas C-2 resulted in considerably higher primary energy savings (∼58%) and solar fraction (∼14.4%) in comparison to C-1 and C-3. The serial connection of the entire solar field resulted in better primary energy savings in C-2 while for C-1 and C-3 parallel arrangement gave rise to higher primary energy savings than the serial arrangement.