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Numerical investigation of a large air-cooled steam condensor.
Thesis (MEng)--Stellenbosch University, 2021.
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| Format: | Thesis |
| Language: | en_ZA |
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2021
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| _version_ | 1867614068195459072 |
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| access_status_str | Open Access |
| author | Siavhe, A. W. |
| author2 | Van der Spuy, S. J. |
| author_browse | Siavhe, A. W. Van der Spuy, S. J. |
| author_facet | Van der Spuy, S. J. Siavhe, A. W. |
| author_sort | Siavhe, A. W. |
| collection | Thesis |
| description | Thesis (MEng)--Stellenbosch University, 2021. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/123603 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:46:09.042Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/123603 Numerical investigation of a large air-cooled steam condensor. Siavhe, A. W. Van der Spuy, S. J. Meyer, C. J. Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. OpenFoam Air-Cooled-Condenser Computational fluid dynamics Wind waves Numerical analysis Thesis (MEng)--Stellenbosch University, 2021. ENGLISH ABSTRACT: This study investigates physical ways of improving the performance of a large Air-Cooled-Condenser (ACC), with the influence of the turbine hall building included under adverse wind conditions. Open-source computational fluid dynamics (CFD) tools were used to study these wind effects. Custom solvers were developed in OpenFOAM 5.0. Three ways of mitigating the adverse wind effects were investigated. The first approach involved removal of the turbine hall cladding. The second approach involved addition of cruciform walls. Lastly, the third approach involved replacing the fans along the windward unit positions. Four multiple fan ACC array models were developed. Each model consisted of 30 fans in 5 × 6 array configuration. The first model represented the base case ACC array. The three remaining models represented one of the three mitigating methods for wind effects which were investigated in this study. Two wind directions and two wind speeds were considered. For wind direction of 120◦, for all the ACC array models, it was found that the flow distortion is most severe on the windward fans, while fan units closer to the turbine hall building experienced good performance, with volumetric effectiveness increasing with an increase in wind speed. This is because the turbine hall enables harnessing of the wind energy by deflecting flow into the fans near it. For both the reference wind speeds, wind direction of 232.5◦ leads to the worst ACC performance for all the ACC arrays investigated in this study. At this wind direction, severe flow distortion and separation at the inlet of windwards fans resulted in these fans experiencing severe back-flow. This effect was less severe on the windwards fans serviced by the B2a-fans of the combined fan ACC array. The removal of the turbine hall cladding lead to an increase in volumetric flow rate for the non-windward fans. However, the removal of the turbine hall cladding increases the number windward fans, thus the overall ACC performance is not improved. The addition of cruciform walls beneath the ACC had a marginal influence on the performance of the ACC array. The investigation however only considered one format of cruciform wall. For all wind conditions considered, the combined fans ACC with B2a-fans on the windward positions shows the greatest performance improvements. It is therefore recommended as a physical way of improving the performance of an ACC array under adverse wind conditions. AFRIKAANSE OPSOMMING: Hierdie studie ondersoek fisiese wyses waarop die werking van ’n groot Lugverkoelde Kondensor (LVK) verbeter kan word, met inagneming van die effek van ’n nabygele ̈e turbienesaal onder atmosferiese windtoestande. Oop-bron Numeriese Berekenings Vloeimeganika (BVM) sagteware is gebruik om hierdie effekte te ondersoek. Doel-spesifieke oplosroetines is hiervoor ontwikkel in OpenFOAM 5.0. Drie metodes om die wind newe-effekte te verminder is ondersoek. Die eerste metode het die verwydering van die turbinesaal wande behels en die tweede metode het die gebruik van ’n windkruis behels. Laastens, het die derde metode die vervanging van die waaiers langs die wind-op eenhede se posisies behels. Vier multi-waaier LVKs is ontwikkel. Elke model het 30 waaiers in ’n 5 × 6 matriks bevat. Die eerste model het die basisgeval LVK verteenwoordig. Die drie oorblywende modelle het die drie wind-effek verminderingsmetodes, wat as deel van hierdie studie ondersoek is, verteenwoordig. Twee windrigtings en twee windspoede is ondersoek. Vir ’n 120◦ windrigting, vir al die LVK modelle, is daar gevind dat die windversteuring die beduidendste is vir die wind-op waaiers, terwyl waaiers wat nader aan die turbienesaal is beter vaar, met ’n volumetriese effektiwiteit wat toeneem met ’n toename in windspoed. Die effek is toe te skryf aan die turbienesaal wat die windenergie benut deur die vloei in die waaiers in sy onmiddellike omgewing in te deflekteer. Vir beide verwysings windspoede, lei ’n windrigting van 232.5◦ tot die swakste werkverrigting van al die LVKs wat in hierdie studie ondersoek is. Teen hierdie windrigting het beduidende wegbreking en vloeiversteuring by die waaierinlate van die wind-op waaiers daartoe gelei dat hierdie waaiers terugvloei ondervind. Hierdie effek was minder beduidend by waaierposisies waar die B2a-waaier op die ”gekombineerde”LVK ge ̃A ̄nstalleer is. Die verwydering van die wande van die turbienesaal het wel tot ’n verhoging in die volumevloeitempo vir die nie wind-op waaiers gelei, maar die verwydering van hierdie wande het die hoeveelheid wind-op waaiers verhoog, so die oorkoepelende werkverrigting van die LVK is nie verbeter nie. Die byvoeging van ’n windkruis onder die LVK het ’n marginale verbetering in die werkverrigting teweeg gebring. Die ondersoek het egter net een windkruis konfigurasie ondersoek. Vir al die windtoestande wat ondersoek is, wys die gekombineerde LVK met B2a-waaiers in die wind-op posisies die grootste verbetering in werkverrigting. Hierdie metode word dus aanbeveel as ’n fisiese wyse waarop die werkverrigting van ’n LVK onder windtoestande verbeter kan word. Masters 2021-06-23T15:13:03Z 2021-12-22T14:11:45Z 2021-06-23T15:13:03Z 2021-12-22T14:11:45Z 2021-12 Thesis http://hdl.handle.net/10019.1/123603 en_ZA 122 pages application/pdf |
| spellingShingle | OpenFoam Air-Cooled-Condenser Computational fluid dynamics Wind waves Numerical analysis Siavhe, A. W. Numerical investigation of a large air-cooled steam condensor. |
| title | Numerical investigation of a large air-cooled steam condensor. |
| title_full | Numerical investigation of a large air-cooled steam condensor. |
| title_fullStr | Numerical investigation of a large air-cooled steam condensor. |
| title_full_unstemmed | Numerical investigation of a large air-cooled steam condensor. |
| title_short | Numerical investigation of a large air-cooled steam condensor. |
| title_sort | numerical investigation of a large air cooled steam condensor |
| topic | OpenFoam Air-Cooled-Condenser Computational fluid dynamics Wind waves Numerical analysis |
| url | http://hdl.handle.net/10019.1/123603 |
| work_keys_str_mv | AT siavheaw numericalinvestigationofalargeaircooledsteamcondensor |