Natural Convection Heat Transfer from Circular Finned Helical Coil Heat Exchanger in Air

Kumar, Ramesh; Prakash, Chandra; Raj, Gaurav

doi:10.1007/978-981-32-9099-0_10

Cited by 1 publication

(1 citation statement)

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“…They affirmed that strip fins enhance the performance of the coil in both orientations for all studied range of airflow. Rajesh Kumar et al [19] experimentally investigated that finned helical coil heat exchanger exhibits heat transfer coefficient 15-16% higher than an un-finned heat exchanger. They also observed a drop in temperature with an increased flow rate of hot water in the test section.…”

Section: Introductionmentioning

confidence: 99%

Thermal performance enhancement studies on a circular finned coil-in-shell heat exchanger using graphene oxide nanofluid

Rai¹,

Hegde²

2020

SN Appl. Sci.

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The objective of this study is to investigate the effect on heat transfer augmentation by the combined effect of circular fins directly attached to the helical surface of the coil in two different orientations (45° and 90°) and Graphene Oxide nanofluid as a heat transport agent, in a coil-in-shell heat exchanger. The attached circular fins not only act as turbulators on the shell side but could also add to heat transfer from the hot side to the cold side, by a combined mechanism of conduction and convection. The experiment is conducted at constant heat flux, with the cold nanofluid in the coil side and hot air in the shell side. Test runs are taken by varying hot air velocities from 1 m/s to 5 m/s, keeping fixed volume concentration of nanofluid (0.05-0.15%) and flow rate (500 ≤ Re ≤ 5500) one at a time. Experimental results indicated significant enhancement in heat transfer performance for the finned configuration. For 90º and 45º fin orientation-0.15% volume concentration of nanofluid, the maximum heat transfer increase is by 78.46%, and 82.22%, Nusselt number increase is by 32.57%, 60.79% respectively, at a hot air velocity of 3 m/s. The coil side pressure drop and friction factor increased to 32.72% and 24.64% for 0.15% GO nanofluid when compared to pure water at the maximum flow rate. The thermal-hydraulic performance improvement is nearly twofold with 45º fin orientation-GO nanofluid combination.

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Section: Introductionmentioning

confidence: 99%