Publication Cover
Numerical Heat Transfer, Part A: Applications
An International Journal of Computation and Methodology
Volume 78, 2020 - Issue 12
315
Views
8
CrossRef citations to date
0
Altmetric
Original Articles

Supercritical CO2 flowing upward in a vertical tube subject to axially nonuniform heating

, , ORCID Icon & ORCID Icon
Pages 717-736 | Received 16 Jul 2020, Accepted 30 Jul 2020, Published online: 14 Aug 2020
 

Abstract

Three different types of axially nonuniform heat fluxes are imposed on the outer surface of a vertical circular tube with turbulent supercritical carbon dioxide (S-CO2) flowing upward. The aim is to explore the potential in adjusting the axial heat flux distribution to optimize heat transfer. Numerical simulations are conducted to investigate how varying the heat flux in the axial direction influences several convective heat transfer behaviors (DHT: deteriorated heat transfer, NHT: normal heat transfer, EHT: enhanced heat transfer). It was found that DHT can be restrained by decreasing the local heat flux in the entrance region. Superior local heat transfer performance is realized for cases with a nonuniform heat flux defined by a piecewise linear function. The present study provides fundamental insight into the mechanisms of heat transfer under a varying axial heat flux and shows the promise of adjusting the axial heat flux distribution to obtain NHT, or even EHT, for S-CO2 flowing upward in a vertical tube.

Additional information

Funding

This work was sponsored by the National Natural Science Foundation of China (51676163), the National 111 Project (B18041), and the Fundamental Research Funds of Shenzhen City (JCYJ20170306155153048).

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.