Experimental investigation of single-phase and two-phase closed thermosyphon solar water heater systems

摘要

This study represents an experimental performance comparison between single-phase and two-phase closed thermosyphon solar water heater systems (SWHS). For this aim, two identical small-scale SWHSs were constructed side-by-side. The tests were performed under same environmental and load conditions. In the first one of these systems, water was used as working fluid in the solar collector in the conventional SWHS called single-phase. In the second one of these systems, R-134a was used as working fluid in two-phase SWHS. The performance of these systems under clear-sky conditions were investigated in July under the field conditions of Konya in Turkey. In both of these systems, the temperatures of collector inlets and outlets and water storage tanks were measured. Instantaneous solar radiation data were also taken from Konya Directorship of Meteorology Citation. Cumulative efficiencies of two-phase and single-phase systems by daily were determined. When the two-phase system is compared with the conventional single-phase system, it is derived that the two-phase system is 42.8% more efficient than the other.