A numerical investigation of three different thermosyphon solar water heating systems

This work presents a theoretical evaluation of the performance of three types of thermosyphon solar water heating (TSWH) systems with flat-plate collectors considering different weather conditions. The flat-plate solar collectors considered are the absorber–pipe lower bond configuration (Type I), the absorber–pipe side bond configuration (Type II) and the absorber–pipe upper bond configuration (Type III). The performance of the three heaters have been investigated numerically under the same conditions. The average values of the energetic and exergetic efficiencies, for one of the weather conditions are: 39.47% and 18.21% for Type I, 34.86% and 15.45% for Type II, 32.28% and 13.8% for Type III. This study reveals that, the thermal performances obtained with Type I TSWH is always greater than the two others, and that this configuration leads to an improvement in the efficiency–temperature rise couple, followed by Type II TSWH system.