Subjects
-Tags
Mechanical, Power, Production, Design and Mechatronics Engineering.
Abstract
The effects of insulating wires (acting as turbulators only), with circular cross section of 2mm diameter, forming a coil of different pitches on the heat transfer rates are experimentally investigated. The investigation is performed for turbulent water stream in a double-pipe heat exchanger for both parallel and counter flows (for comparison) with cold water in the shell side. The experiments are performed for flows with Reynolds numbers ranging from 4,000 to 14,000. Three different spring coiled wire pitch values are used. The experimental results reveal that the use of coiled circular wire turbulators leads to a considerable increase in heat transfer over those of a smooth wall tube. The mean Nusselt number increases with the rise of Reynolds number and the increasing of pitch for both parallel and counter flows. The convective heat transfer coefficient for the turbulent flow was found to increase with turbulators for all coiled wire pitch values with the highest enhancement of about 450% for the counter flow while it was 400% for the parallel one. Correlations for mean relative Nusselt numbers and coiled wire pitch are provided.
DOI
10.21608/jesaun.2012.114407
Keywords
heat transfer enhancement, Coiled wire, Turbulators, turbulent pipe flow, heat exchanger
Authors
MiddleName
-Affiliation
Mechanical Engineering Department, Tabbin Institute for Metallurgical Studies, Cairo, Egypt,
Email
alaa_sadegh@yahoo.com
City
-Orcid
-MiddleName
-Affiliation
Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
Email
mahabib@kfupm.edu.sa
City
-Orcid
-Link
https://jesaun.journals.ekb.eg/article_114407.html
Detail API
https://jesaun.journals.ekb.eg/service?article_code=114407
Publication Title
JES. Journal of Engineering Sciences
Publication Link
https://jesaun.journals.ekb.eg/
MainTitle
HEAT TRANSFER CHARACTERISTICS IN A DOUBLE-PIPE HEAT EXCHANGER EQUIPPED WITH COILED CIRCULAR WIRES