A designed wall roughness approach to improve turbulent heat transfer to supercritical CO2 flowing in horizontal tubes

Title

A designed wall roughness approach to improve turbulent heat transfer to supercritical CO2 flowing in horizontal tubes

 Author

Wang, Jianyong (Sun Yat-sen University)
Yang, Jun (Sun Yat-sen University)
Gong, Jishuang (Sun Yat-sen University)
Zhao, Chunrong (University of Sydney)
Hooman, K. (TU Delft Process and Energy) ORCID 0000-0003-0282-7960

 Department

Process and Energy

 Date

2022

 Abstract

Supercritical flow through a horizontal pipe leads to a non-uniform peripheral wall temperature distribution even when the wall heat flux is kept constant and uniform. This is attributed to lower heat transfer coefficient at the top section where the denser fluid tends to sink. Hence, to obtain a uniform wall temperature, a designed wall roughness is devised. Uniform sand-grain roughness is employed to only partly cover the top half of the pipe wall. Numerical simulations were conducted using the SST k−ω turbulence model. The simulation results indicate that our proposed design can lead to a more uniform heat transfer distribution over the wall periphery compared with the smooth pipe. An extreme case was also considered where the inner wall was completely covered with roughness elements. While heat transfer augmentation was observed for this case, the excess pressure drop was prohibitively higher compared with a pipe with designed wall roughness.


 Subject

Horizontal pipe
Partly
Sand-grain roughness
Supercritical flow
Uniform heat transfer

 To reference this document use:

http://resolver.tudelft.nl/uuid:56123a69-f352-4f48-8c08-c05ea600c285

 DOI

https://doi.org/10.1016/j.supflu.2022.105738

 Embargo date

2023-03-08

 ISSN

0896-8446

 Source

The Journal of Supercritical Fluids, 190

 Bibliographical note

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

 Part of collection

Institutional Repository

 Document type

journal article

 Rights

© 2022 Jianyong Wang, Jun Yang, Jishuang Gong, Chunrong Zhao, K. Hooman
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