*Assistant Professor, Theni Kammavar Sangam College of Technology, Theni, Tamilnadu, India
**Professor, Odaiyappa College of Engineering & Technology, Theni, Tamilnadu, India
***Professor, Department of Mechanical Engineering, Star Lion College of Engineering & Technology, Thanjavr, Tamilnadu, India
Online published on 14 October, 2016.
Experimental investigation of heat transfer and friction factor characteristics of thermosyphon solar water heater with helical screw tape of various twist ratios(Y=3, 4, 5 and 6) has been studied. Compared to other twist ratio, the minimum twist ratio 3, offers higher Nusselt number, friction factor and Thermal performance. The average Nusselt number, friction factor and thermal efficiency for helical screw tape collector with minimum twist ratio 3 are 13.86, 0.111 and 63.62% respectively. Whereas the increasing twist ratio decreases the above performance. The heat removal factor for screw tape collector with twist ratio 3 has 54.4% higher than plain tube collector. Correlations developed for friction factor and Nusselt number has been verified and deviation falls within ±13%.
Thermosyphon, Helical screw tapes, Centre core rod, Average Nusselt number, thermal efficiency
