Numerical modelling of a solar thermal cooling system under arid weather conditions

In Middle East, the electricity demand often increased rapidly during the summer seasons due to high outdoor temperatures. The extreme ambient air temperatures lead to extensive use of air-conditioning systems in order to reduce the indoor air temperatures. Since the cooling demand during the summer seasons for office buildings coincides with the solar energy gain, this paper presents a study of utilising thermal cooling system for an office space based on the weather conditions in Doha, Qatar. The simulations are carried using TRNSYS simulation program with the typical meteorological year data file to determine the optimum values of the design parameters. The studied parameters include solar collector area, collector slope, tank volume, water flow rate and heat exchanger effectiveness. The results show the optimum system for 4.5 kW adsorption cooling system requires an area of 23.4 m2 evacuated tube collector titled at 24° from horizontal with a water storage tank of 0.3 m3. Also, local weather data between May and June 2012 are recorded and utilised to analyse the optimum parameters. Study shows that the adsorption cooling system can reduce the electricity consumption by 47% compared to a compression cooling system.