Experimental Studies on the Thermal Performance of the Wall-Type All-Glass Evacuated Tube Solar Water Heater

Abstract

Based on the test methods for solar water heating systems, the useful energy output, water temperature rise and thermal efficiency of the wall-type all-glass evacuated tube collectors fixed at a large tilt angle (≥60o) have been conducted by the experimental test in Kunming. The results show that the average thermal efficiency varies from 35% to 50%, the useful energy output decreases from 13.1MJ to 8.8MJ and the water temperature rise decreases from 31.3 °Cto 20.9°C when the tilt angle increases from 60o to 90o. These results can provide some useful experimental data support for the application of the all-glass evacuated tube solar collector integrated into the wall of the high-rise buildings.