Abstract
An experimental study has been conducted for natural convection heat transfer over the outer surface of circular finned and unfinned helical coil heat exchanger. Hot water flowing in the range of 1–3 l/min has been taken as working fluid and is cooled by ambient air at 32.5 ± 0.1 °C. The volume flow rate of hot water covers the Reynolds number from 4230 to 12,720 and Prandtl number around 3.7. The temperature of hot water at the inlet of test section is maintained at 50 ± 0.1 °C. The heat transfer rate of hot water has been investigated. Better outside heat transfer coefficient has been found for circular finned helical coil heat exchanger than unfinned one. It is also observed that the temperature drop decreases with increase in hot water flowing through test section.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- A:
-
Surface area (m2)
- D:
-
Helical coil diameter (m)
- d:
-
Tube diameter (m)
- h:
-
Heat transfer coefficient (W/m2K)
- k:
-
Thermal conductivity (W/mK)
- L:
-
Length of tube (m)
- Nu:
-
Nusselt number (dimensionless)
- P:
-
Pitch of helical coil (m)
- Pr:
-
Prandtl number (dimensionless)
- Q:
-
Heat transfer rate (W)
- Re:
-
Reynolds number (dimensionless)
- T:
-
Temperature (°C)
- V:
-
Volume flow rate of hot water (m3/s)
- ρ:
-
Density (kg/m3)
- Cp:
-
Specific heat (J/kg K)
- θ:
-
Bulk mean temperature (°C)
- a:
-
Ambient air
- I:
-
Inlet/Inner
- o:
-
Outlet/Outside
- w:
-
Water
References
Zimparov, V.: Energy conservation through heat transfer enhancement techniques. Int. J. Energy Res. 26(7), 675–696 (2002)
Kumbhar, D.G., Sane, N.K.: Heat transfer enhancement in a circular tube twisted with swirl generator: a review. In: Proceedings 2010 3rd International Conference on Advances in Mechanical Engineering SVNIT Surat, pp. 188–192. Surat (2010)
Dewan, A., Mahanta, P., Raju, K.S., Kumar, P.S.: Review of passive heat transfer augmentation techniques. Proc. Inst. Mech. Eng. Part A J. Power Energy 218(7), 509–527 (2004)
Liu, S., Sakr, M.: A comprehensive review on passive heat transfer enhancements in pipe exchangers. Renew. Sustain. Energy Rev. 19, 64–81 (2013)
Ali, M.E.: Laminar natural convection from constant heat flux helical coiled tubes. Int. J. Heat Mass Transf. 41(14), 2175–2182 (1998)
Ali, M.E.: Natural convection heat transfer from vertical helical coils in oil. Heat Transf. Eng. 27(3), 79–85 (2006)
Prabhanjan, D.G., Rennie, T.J., Raghavan, G.V.: Natural convection heat transfer from helical coiled tubes. Int. J. Therm. Sci. 43(4), 359–365 (2004)
Pawar, S.S., Sunnapwar, V.K.: Studies on convective heat transfer through helical coils. Heat Mass Transf. 49(12), 1741–1754 (2013)
Park, J.H., Moon, J.Y., Chung, B.J.: Natural convection of an inclined helical coil in a duct. Int. Commun. Heat Mass Transf. 59, 11–16 (2014)
Nada, S.A., Eid, E.I., Abd El Aziz, G.B., Hassan, H.A.: Performance enhancement of shell and helical coil water coolers using different geometric and fins conditions. Heat Transf. Asian Res. 45(7), 631–647 (2016)
Andrzejczyk, R., Muszyński, T.: Performance analyses of helical coil heat exchangers. The effect of external coil surface modification on heat exchanger effectiveness. Arch. Thermodyn. 37(4), 137–159 (2016)
Rogers, G.F.C., Mayhew, Y.R.: Heat transfer and pressure loss in helically coiled tubes with turbulent flow. Int. J. Heat Mass Transf. 7(11), 1207–1216 (1964)
Kays, W., Crawford, M., Weigand, B.: Convective Heat and Mass Transfer, 4th edn. McGraw Hill, Singapore (2005)
Yildiz, C., Biçer, Y., Pehlivan, D.: Heat transfers and pressure drops in rotating helical pipes. Appl. Energy 50(1), 85–94 (1995)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Kumar, R., Chandra, P., Raj, G. (2020). Natural Convection Heat Transfer from Circular Finned Helical Coil Heat Exchanger in Air. In: Singh, I., Bajpai, P., Panwar, K. (eds) Trends in Manufacturing Processes. Lecture Notes on Multidisciplinary Industrial Engineering. Springer, Singapore. https://doi.org/10.1007/978-981-32-9099-0_10
Download citation
DOI: https://doi.org/10.1007/978-981-32-9099-0_10
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-32-9098-3
Online ISBN: 978-981-32-9099-0
eBook Packages: EngineeringEngineering (R0)