Modeling of a Solar Assisted Water-libr Absorption Refrigeration System for Summer Airconditioning of an Office Room

Exploitation of solar energy for achieving low temperature is an active area of research at present owing to the concern over suitable alternatives to synthetic refrigerants and large electricity consumption by conventional vapour compression systems. Present work theoretically design and analyze the performance of a solar flat-plate collector-driven water-Lithium bromide absorption refrigeration system for comfort conditioning of an office room during working hours of summer months. Mathematical models of absorption chiller, flat-plate collector, water storage tank with auxiliary heating unit and conditioned-space psychrometry have been coupled with real weather data of Kolkata, India. Ten collectors of 1.5 m x 1 m each, alongside a storage tank of 15 m 3 capacity have been found to be adequate for the selected space. Absorption system exhibits an optimum generator temperature corresponding to maximum COP for any condenser-evaporator temperature combination and corresponding contour maps have been presented. Integrated system COP has also been found to attain maxima for a particular solar insolation level. It is possible to maintain collector efficiency greater than 40% almost throughout the day. Supply tank water temperature has been found to be slightly higher at the end of the day compared to the early morning for summer months, whereas it remains slightly lower during post-monsoon months. Use of auxiliary heaters has been suggested rather than augmenting the number of collectors.