Augmenting the Performance of Evacuated Tube Solar Water Heater Using Perforated Wavy Tape

A significant portion of energy is wasted within the evacuated tube collector due to the formation of an inactive zone at the bottom of the tube, resulting in decreased efficiency. The current study presents an experimental investigation of the energetic and exergetic analysis of an evacuated tube solar water heater associated with perforated wavy tubes. A comparative analysis of conventional solar water heater and water heater with three different thermal enhancement methods was carried out: the use of wavy tape inserts (Plain WT), perforated wavy tape with 6 mm equilateral triangles (6 PWT), and perforated wavy tape with 9 mm equilateral triangles (9 PWT). The results showed that the insertion of wavy tapes improved the temperature of the ETC solar water heater's tank water as well as the temperature of the evacuated tubes. The highest hourly efficiency was recorded as 83.33% for the ETSC with 6 PWT, followed by 81.8%, 78.3%, and 75.6% for the ETSC with 9 PWT, ETSC with plain WT, and ETSC without WT, respectively. The effect of perforated wavy tape ETSC (6 PWT) resulted in a daily energy efficiency of 49.3%, which is greater than without WT (38.7%), with plain WT (44.9%), and with 9 PWT (47.8%). The average exergy efficiency of ETSC with 6 PWT was higher by 70.1%, 35.1%, and 13.1% compared to without WT, with plain WT, and with 9 PWT, respectively.