The use of parabolic trough collectors for solar cooling - A case study for Athens climate

Solar cooling is a state of the art technology in the last years, especially for countries with high irradiation level as Greece. The objective of this study is to determine the performance of an efficient solar cooling system for Athens, the most populated city in Greece. The examined solar cooling system is a one stage water/lithium-bromide absorption chiller driven by a parabolic trough collector coupled with a storage tank. A numerical model is developed in order to simulate the dynamic performance of this system. Many parameters have been investigated through sensitivity analyses and their optimum values are determined. The mass flow rates and the storage tank volume are the parameters that have been examined parametrically. The final results proved that by using a PTC module with an aperture area of 14 m2, a building area of about 25 m2 can be cooled for 13 h daily during the summer period. The optimum specific mass flow rate was determined to 0.03 kg/sm2 and the optimum storage tank volume to 0.3 m3. Moreover, a case study for a typical building of 100 m2 is presented with very satisfying results, where four PTC modules are used in parallel connection.