Experimental studies on heat transfer and friction factor characteristics of forced circulation solar water heater system fitted with helical twisted tapes

Journal Article · Sun Nov 15 04:00:00 EST 2009 · Solar Energy

DOI:https://doi.org/10.1016/J.SOLENER.2009.07.006· OSTI ID:21236000

Jaisankar, S ^[1]; Radhakrishnan, T K; Sheeba, K N ^[2]

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1. Department of Mechanical Engineering, Oxford Engineering College, Tiruchirappalli 620009, Tamil Nadu (India)
2. Department of Chemical Engineering, National Institute of Technology, Tiruchirappalli 620015, Tamil Nadu (India)

Experimental investigation of heat transfer, friction factor and thermal performance of twisted tape solar water heater with various twist ratios has been conducted and the results are compared with plain tube collector for the same operating conditions with Reynolds number varied from 3000 to 23,000. Experimental data from plain tube collector is validated with the fundamental equations and found that the discrepancy is less than {+-}5.35% and {+-}8.80% for Nusselt number and friction factor, respectively. Correlations have been developed for Nusselt number and friction factor with various twist ratios (Y = 3, 4, 5, 6) and are compared with the experimental values. Results conclude that, heat transfer and pressure drop are higher in twisted tape collector compared to the plain one. Among the various twist ratios, the minimum twist ratio 3 is found to enhance the heat transfer and pressure drop due to swirl generation. As the twist ratio increases, the swirl generation decreases and minimizes the heat transfer and friction factor. (author)

• OSTI ID: 21236000
• Journal Information: Solar Energy, Journal Name: Solar Energy Journal Issue: 11 Vol. 83; ISSN 0038-092X; ISSN SRENA4
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
CORRELATIONS
EXPERIMENTAL DATA
FORCED CONVECTION
FRICTION FACTOR
HEAT TRANSFER
NUSSELT NUMBER
PERFORMANCE
PRESSURE DROP
REYNOLDS NUMBER
SOLAR WATER HEATERS
TUBES