Investigation of newly designed Alternate Perforated V-Notch (APVN) twisted tape with heat transfer characteristics

Abstract

Swirl device is seen as a path to enhance the efficiency of a thermal switch. Swirl device with fabricated form of porosity and v-cuts twisted tape (tt) inner pipe insert helps to augment performance by improving the heat transfer (U) coefficient. This work is related to the thermal performance factor (TPF), friction factor (ff) and Nusselt (NNu) number in the inner tube inserted with a innovative design of Alternate Perforated V-Notch (APVN) tape having twisted ratio 6.25 incorporating porosity amount of Rp = 1.087% and width (w/W) ratio = 0.333, were investigated features to improve heat transfer rate. Enhancement in turbulent generation of the primary flow into the secondary flow with this design. Experiment test was performed on a pipe in pipe tubes of (d) internal diameter of 0.013 m with test section length of 0.9 m. Temperature of the warm water had kept constant at 60 °C within the Reynolds number range of 2246–16,224. The heat exchanger with empty tube (without tt) and the input of normal twisted tape (tt) has been checked. In addition to the investigated range, NNu, ff and TPF in the tube with APVN twisted tape insertion were observed (Rp - ratio) 1.833–2.276, 2.155–4.549 and 1.84–1.778 times more than the values of empty tube. The presented work is very useful in the field of energy conservation through maximum transfer of heat in the industrial process.

Keywords

• Heat augmentation
• V-notch-twisted tape
• Passive technique
• Pipe in pipe heat exchanger
• Porosity
• Thermal efficiency