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Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces
Dissertation (MEng)--University of Pretoria, 2017.
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University of Pretoria
2017
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| _version_ | 1867613463168155648 |
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| access_status_str | Open Access |
| author2 | Slabber, Johan F.M. |
| author_browse | Slabber, Johan F.M. |
| author_facet | Slabber, Johan F.M. |
| collection | Thesis |
| dc_rights_str_mv | © 2017 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng)--University of Pretoria, 2017. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/62792 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:36:32.683Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/62792 Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces Slabber, Johan F.M. marco.alfama@gmail.com Meyer, Josua P. Alfama, Marco Heat transfer Nucleate boiling Flow boiling Roughness UCTD Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-13 SDG-13: Climate action Dissertation (MEng)--University of Pretoria, 2017. Modern nuclear reactors still use Zirconium-4 Alloy (Zircaloy®) as the cladding material for fuel elements. A substantial amount of research has been done to investigate the boiling heat transfer behind the cooling mechanism of the reactor. Boiling heat transfer is notoriously difficult to quantify in an acceptable manner and many empirical correlations have been derived in order to achieve some semblance of a mathematical model. It is well known that the surface conditions on the heat transfer surface plays a role in the formulation of the heat transfer coefficient but on the other hand it also has an effect on the pressure drop alongside the surface. It is therefore necessary to see whether there might be an optimum surface roughness that maximises heat transfer and still provides acceptably low pressure drop. The purpose of this study was to experimentally measure pressure drop and heat transfer associated with vertical heated tubes surrounded by flowing water in order to produce flow boiling heat transfer. The boiling heat transfer data was used to ascertain what surface roughness range would be best for everyday functioning of nuclear reactors. An experimental set-up was designed and built, which included a removable panel that could be used to secure a variety of rods with different surface roughnesses. The pressure drop, surface temperature, flow rate and heat input measurements were taken and captured in order to analyse the heat transfer and friction factors. Four rods were manufactured with different roughnesses along with a fifth rod, which remained standard. These rods were tested in the flow loop with water in the upward flow direction. Three different system mass flow rates were used: 0kg/s, 3.2kg/s and 6.4kg/s. Six repetitions were done on each rod for the tests; the first repetition was not used in the results since it served the purpose to deaerate the water in the flow loop. The full range of the power input was used for each repetition in the tests. For the heat transfer coefficient at a system mass flow rate of 3.2kg/s, satisfactory comparisons were made between the test results and those found in literature with an average deviation of 14.53%. At 6.4kg/s system mass flow rate the comparisons deviated on average 55.45%. The velocity of the fluid in the test section was calculated from the pressure drop and was validated using separate tests. The plain rod, with no added roughness, was found to be the optimal surface roughness which is what is used in industry today. The flow loop was in need of a couple of redesigns in order to produce more accurate results. Future work suggestions include adding more rods in the test section in order to investigate the nature of heat transfer in a rod bundle array as well as implementing all the suggested changes listed in the conclusion. mi2025 Mechanical and Aeronautical Engineering MEng Unrestricted SDG-07: Affordable and clean energy SDG-09: Industry, innovation and infrastructure SDG-13: Climate action 2017-10-13T13:41:23Z 2017-10-13T13:41:23Z 2017-09-08 2017 Dissertation Alfama, M 2017, Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces, MEng Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/62792> S2017 http://hdl.handle.net/2263/62792 © 2017 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Heat transfer Nucleate boiling Flow boiling Roughness UCTD Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-13 SDG-13: Climate action Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces |
| title | Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces |
| title_full | Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces |
| title_fullStr | Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces |
| title_full_unstemmed | Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces |
| title_short | Theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces |
| title_sort | theoretical and experimental investigation of the heat transfer and pressure drop optimisation on textured heat transfer surfaces |
| topic | Heat transfer Nucleate boiling Flow boiling Roughness UCTD Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-13 SDG-13: Climate action |
| url | http://hdl.handle.net/2263/62792 |