Modelling and Simulation of Solar Absorption Cooling System using TRNSYS

Abstract

In this study, performance analysis of solar assisted single effect absorption cooling system is performed for two system configurations. The analysis is carried out to meet a cooling demand of 298 kW (85TR) for an educational building located in Islamabad (33.71° N, 73.06° E). In configuration-1 (C-1), the return water from absorption chiller always flows towards hot water storage tank which is connected to the solar collector. In configuration-2 (C-2), the return water from absorption chiller may become isolated from the collector-storage tank loop if the water temperature in the storage tank is less than the required temperature i.e. 110℃. Both system configurations are modelled in TRNSYS and dynamic simulations are carried out for the entire summer season. Various performance factors such as solar fraction, collector efficiency and primary energy savings are evaluated to optimize the system components which includes collector tilt, type and size of collector, storage volume. Results demonstrate that C-2 in conjunction with evacuated tube collectors (ETC) results in minimum area per kilowatt of cooling demand and higher monthly collector efficiency than C-1.