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Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes'
Thesis (MEng)--University of Stellenbosch, 2000.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2012
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| _version_ | 1867613773303382016 |
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| access_status_str | Open Access |
| author | Sizani, Xolile L. |
| author2 | Terblanche, E. |
| author_browse | Sizani, Xolile L. Terblanche, E. |
| author_facet | Terblanche, E. Sizani, Xolile L. |
| author_sort | Sizani, Xolile L. |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--University of Stellenbosch, 2000. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/51748 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:41:28.315Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2012 |
| publishDateRange | 2012 |
| publishDateSort | 2012 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/51748 Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes' Sizani, Xolile L. Terblanche, E. Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. Heat exchangers -- Design and construction Dissertations -- Mechanical engineering Theses -- Mechanical engineering Thesis (MEng)--University of Stellenbosch, 2000. ENGLISH ABSTRACT: This report describes the Experimental and Numerical Investigations conducted, during the determination of the structural mechanics of elliptical tubes, viz. the F- and the Atubes. This report is requested in an endeavour to assist Sasol, who is currently busy developing and updating specifications on Air Cooled Heat Exchangers. The objectives of this report therefore are to : (1) determine the strength and the effectiveness of the tube-to-tube-sheet joints. (2) determine the allowable pressure limits on the tubes and (3) investigate the effects of thermal load and vibration on the tube bundle. A series of experiments were conducted to meet these objectives. From a Shear Load experiment it was found that the maximum allowable axial load on the Fand the A-tube is 14.55 kN and 20. 86 kN respectively. Fin Plates were found to have little effect on the bending strength of the tube, w~ilst they have significant effect on the resistance to volumetric expansion of the tube. In fact the more fins per unit length the greater the resistance to volumetric expansion of the tube. These conclusions were drawn from Bending and Pressure Load experiments respectively and supported by FEM analysis of the tube using NASTRAN. When the design pressure limit given by the manufacturer (GEA Air Cooled Systems), were tested using FEM analysis, it was found that they cause no significant deformation and failure of the tubes. Thermal stresses on the tube bundle greatly affect the first tube in the first row (row closest to the flanges) of the tube bundle and it is recommended that provision for thermal expansion be made to reduce these stresses. To reduce vibrations induced by the fan, it is recommended that the natural frequency of the tube bundle must not equal the number of blades (N) times the angular frequency (co) of the fan, or multiples thereof, of each mode of vibration. AFRIKAANSE OPSOMMING: Hierdie tesis beskrywe die Numeriese en Eksperimentele ondersoeke na die sterkte van elliptiese verkoelingsbuise, naamlik die F- en A- tipes. Hierdie werk sal Sasol, wat huidiglik besig is met die opgradering, van spesifikasies vir lugverkoelde hitteuitruilers van nut wees. Die doelwitte van hierdie tesis is om: (1) die sterkte en effektiwiteit van die buis laste was die buis and die buisplaat verdind, te ondersoek, (2) die toelaatbare druklimiete, sowel as (3) die effek wat hitte en vibrasie op 'n buisbundel het, te ondersoek. 'n Reeks eksperimente is uitgevoer om hierdie doelwitte te bevredig. 'n Skuifbelastingseksperiment het aangedui dat die toelaatbare krag wat op 'n F- en A-buis respektiewelik aangewend kan word 14.55 kN en 20.86 kN is. Die ondersoek het aangetoon dat vinne geen noemenswaardige effek op die buigsterkte van die buise gehad het nie, maar dat dit 'n aansienlike verstywingseffek teen volumetriese verandering as gevolg van interne druk, gehad het. Hierdie gevolgtrekkings is bereik deur die Druk- en Buigtoetse wat numeries bevestig is met die NASTRAN eindige element analise (EEA) pakket. EEA het aangetoon dat die druklimiete voorgeskryf deur die buisvervaardiger (GEA Air Cooled Systems) nie noemenswaardige vervorming van die buise tot gevolg gehad het nie. Termiese belastings het 'n groot invloed op die eerste buise (die rye naaste aan die flense) van 'n buisbundel. Die invoeging van uitsettingslaste word aanbeveel om die spannings hier te verminder. Om vibrasie van die buisbundel te verhoed word aanbeveel dat die resonansfrekwensie van die buisbundel nie gelyk is aan die aantal lemme (N) vermenigvuldig met die rotasie frekwensie (co)van die waaier vir elke vibrasiemode. 2012-08-27T11:34:40Z 2012-08-27T11:34:40Z 2000-04 Thesis http://hdl.handle.net/10019.1/51748 en_ZA Stellenbosch University 1 v. (various pagings) : ill. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Heat exchangers -- Design and construction Dissertations -- Mechanical engineering Theses -- Mechanical engineering Sizani, Xolile L. Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes' |
| title | Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes' |
| title_full | Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes' |
| title_fullStr | Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes' |
| title_full_unstemmed | Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes' |
| title_short | Evaluate the use of elliptical finned tubes in heat exchanger design and performance : 'the structural characteristics of finned tubes' |
| title_sort | evaluate the use of elliptical finned tubes in heat exchanger design and performance the structural characteristics of finned tubes |
| topic | Heat exchangers -- Design and construction Dissertations -- Mechanical engineering Theses -- Mechanical engineering |
| url | http://hdl.handle.net/10019.1/51748 |
| work_keys_str_mv | AT sizanixolilel evaluatetheuseofellipticalfinnedtubesinheatexchangerdesignandperformancethestructuralcharacteristicsoffinnedtubes |