Intensification of thermal characteristics of flat plate solar water heater using triangular perforated wavy tape

Abstract

The efficiency of the flat Plate Solar water heater has improved experimentally using passive methods. Experiments have shown that the addition of wavy tape (WT), 6 mm perforated wavy tape (PWT), and 9 mm perforated wavy tape (PWT) to a forced circulation solar water heater improves rate of heat transfer (Nu), friction factor (f), and effectiveness. Wavy tape inside the pipes induces secondary swirl flow, which improves mixing and increases heat transfer coefficients. The heat transfer rate (Nu) is increased by the incorporation of wavy tape; FPC with 6 PWT was higher than FPC without WT, FPC with plain WT, and FPC with 9 PWT by 20.83%, 14.85% and 6.25%, respectively. The maximum temperature difference of FPC with 6 PWT was higher than FPC without WT, FPC with plain WT, and FPC with 9 PWT by 61.9%, 22.9%, and 12.62% respectively. The maximum efficiencies value observed was 37.55%, 49.46%, 54.013%, and 51.03% for FPC without WT, FPC with plain WT, FPC with 6 PWT, and FPC with 9 PWT, respectively.