Thermal modelling of feedwater heaters

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dc.contributor.advisorFuls, Wimen_ZA
dc.contributor.advisorDu Preez, Francoisen_ZA
dc.contributor.authorAllie, Mohammed Nazieren_ZA
dc.date.accessioned2016-07-14T12:21:45Z
dc.date.available2016-07-14T12:21:45Z
dc.date.issued2016en_ZA
dc.description.abstractManufacturers of feedwater heaters (FWHs) are obliged to disclose a specification sheet to the client that describes their FWH design. However, the client is unable to verify the performance of this FWH design without comparing it to the results that are predicted by a thermal model. An additional limitation is that the manufacturer will only disclose the minimum number of design parameters. The purpose of this study was to develop a thermal model that can predict the performance of a FWH. The model requires the minimum design input data to predict the performance parameters that may be compared to values predicted by the vendor. A FWH in a regenerative water-steam Rankine cycle achieves heat transfer to the feedwater by condensing steam on the shell side. This is called a single zone FWH. The tube plate type FWH is the most common type of FWH referenced in literature but the following variations may exist: • The Eskom fleet consist of both tube plate and header type FWHs. • FWHs may be orientated vertically or horizontally. Internal shrouded regions, that define it as a 2 or 3 zone FWH, may be present in the FWH. The length of the drains cooler (DC) zone may either be identified as long or short. A general model was required to capture all these design variations. Plant visits were arranged with engineers at several power stations to obtain the minimum input data and to confirm that these FWH design variations existed within the Eskom fleet. The model was based on existing tube plate models found in literature. It was then extended to accommodate the FWH variations mentioned above. A further improvement was made by including an additional heat transfer sub-zone that removes excess superheat in the condensing (COND) zone. The vendor does not disclose the correlations used to predict the film heat transfer coefficients (h) in their design. Therefore, the user is granted the option of selecting a correlation from a list of popular correlations, specific to a heat transfer mode. Note that the uncertainty associated with this thermal model is affected by the uncertainty of each correlation selected in the model.en_ZA
dc.identifier.apacitationAllie, M. N. (2016). <i>Thermal modelling of feedwater heaters</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Mechanical Engineering. Retrieved from http://hdl.handle.net/11427/20348en_ZA
dc.identifier.chicagocitationAllie, Mohammed Nazier. <i>"Thermal modelling of feedwater heaters."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Mechanical Engineering, 2016. http://hdl.handle.net/11427/20348en_ZA
dc.identifier.citationAllie, M. 2016. Thermal modelling of feedwater heaters. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Allie, Mohammed Nazier AB - Manufacturers of feedwater heaters (FWHs) are obliged to disclose a specification sheet to the client that describes their FWH design. However, the client is unable to verify the performance of this FWH design without comparing it to the results that are predicted by a thermal model. An additional limitation is that the manufacturer will only disclose the minimum number of design parameters. The purpose of this study was to develop a thermal model that can predict the performance of a FWH. The model requires the minimum design input data to predict the performance parameters that may be compared to values predicted by the vendor. A FWH in a regenerative water-steam Rankine cycle achieves heat transfer to the feedwater by condensing steam on the shell side. This is called a single zone FWH. The tube plate type FWH is the most common type of FWH referenced in literature but the following variations may exist: • The Eskom fleet consist of both tube plate and header type FWHs. • FWHs may be orientated vertically or horizontally. Internal shrouded regions, that define it as a 2 or 3 zone FWH, may be present in the FWH. The length of the drains cooler (DC) zone may either be identified as long or short. A general model was required to capture all these design variations. Plant visits were arranged with engineers at several power stations to obtain the minimum input data and to confirm that these FWH design variations existed within the Eskom fleet. The model was based on existing tube plate models found in literature. It was then extended to accommodate the FWH variations mentioned above. A further improvement was made by including an additional heat transfer sub-zone that removes excess superheat in the condensing (COND) zone. The vendor does not disclose the correlations used to predict the film heat transfer coefficients (h) in their design. Therefore, the user is granted the option of selecting a correlation from a list of popular correlations, specific to a heat transfer mode. Note that the uncertainty associated with this thermal model is affected by the uncertainty of each correlation selected in the model. DA - 2016 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - Thermal modelling of feedwater heaters TI - Thermal modelling of feedwater heaters UR - http://hdl.handle.net/11427/20348 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/20348
dc.identifier.vancouvercitationAllie MN. Thermal modelling of feedwater heaters. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Mechanical Engineering, 2016 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/20348en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Mechanical Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherMechanical Engineeringen_ZA
dc.subject.otherFeedwater heatersen_ZA
dc.subject.othertube plate typeen_ZA
dc.subject.otherheader typeen_ZA
dc.subject.otherEskomen_ZA
dc.subject.otherthermal modellingen_ZA
dc.subject.otherMathcaen_ZA
dc.titleThermal modelling of feedwater heatersen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Eng)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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