Effects of left and right screw tapes in natural circulation solar water heating system

ABSTRACT

The escalating world population for the recent year’s raising the demand of hot water. The hot water can be acquired by conventional and sustainable sources. If it is obtained from conventional sources like relic fuels, which would increase the cost and global warming. The possible of hot water producing from renewable source are two ways such as solar thermal and solar electrical. The conversion efficiency is superior in solar to thermal is nearly 70% when measure up to photovoltaic and is 17%. The increasing hot water demands to increase the research knowledge in the solar water heater and is addressed by many researchers. Few designs of twist and techniques are addressed by researchers in solar water heater. The Left and Right screw tapes is a new design which is to be experimented for the first time in solar water heater. Experimentation carried out with conventional and left-right screw tapes solar collector with twist ratio 3–6 has been studied under natural circulation mode. The overall thermal efficiency for LR3, LR4, LR5, LR6, and conventional are 89.1%, 87.2%, 85%, 83.8%, and 66.4%, respectively. From this comparison, it is clear that the small twist 3 acquires elevated hi, Nu, ΔP, and η at 1.00 pm and is 983 W, 23, 35 N/m², and 89.1% respectively. The above parameters are decreased where the twist ratio increases.

KEYWORDS:

• Buoyancy force
• left and right screw tapes
• swirl flow
• heat intensification
• conventional collector

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Acknowledgments

The authors thanks to Department of science and Technology (SR/FTP/ETA-071/2009) Government of India for providing financial support for this research work.

Additional information

Funding

This work was supported by the Science and Engineering Research Board [SR/FTP/ETA-071/2009].