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Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes
Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2007.
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| Format: | Thesis |
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University of Pretoria
2013
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| _version_ | 1867613515828690944 |
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| access_status_str | Open Access |
| author2 | Meyer, Josua P. |
| author_browse | Meyer, Josua P. |
| author_facet | Meyer, Josua P. |
| collection | Thesis |
| dc_rights_str_mv | © University of Pretoria 2007 C |
| description | Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2007. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/26055 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:37:22.997Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| 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:2263/26055 Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes Meyer, Josua P. Liebenberg, Leon marcel.christians@up.ac.za Christians, Marcel Time fraction Flow pattern Smooth tube Condensation Heat transfer Pressure drop UCTD Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2007. The phase-out of ozone-depleting refrigerants, such as R-12 and R-22, according to the Montreal Protocol of 1987, has provided the incentive to increase the thermal efficiency of current heating and refrigeration systems. The purpose of this study was to increase the accuracy of the predictions of both the heat transfer and pressure drop correlations for condensing refrigerants in the Intermittent flow regime. This was done utilizing a novel method involving the temporal and spectral analysis of the light intensity of the local flow regime, as seen through a sight glass. An experimental setup was designed, built and commissioned specifically for this purpose using refrigerant R-22 and a smooth tube. It was found that the accuracy of the mean heat transfer coefficient predictions increased substantially compared to other leading correlations,particularly at low mass fluxes. In terms of the pressure drop,the predictions also increased in accuracy, and it was found that the time fraction method allows for continuous predictions over flow regime transitions when using local flow-pattern-based pressure drop models. This was previously not possible. Mechanical and Aeronautical Engineering unrestricted 2013-09-07T02:18:26Z 2008-08-05 2013-09-07T02:18:26Z 2007-09-05 2007 2008-07-04 Dissertation a 2007 C53 http://hdl.handle.net/2263/26055 http://upetd.up.ac.za/thesis/available/etd-07042008-181022/ © University of Pretoria 2007 C application/pdf University of Pretoria |
| spellingShingle | Time fraction Flow pattern Smooth tube Condensation Heat transfer Pressure drop UCTD Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes |
| title | Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes |
| title_full | Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes |
| title_fullStr | Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes |
| title_full_unstemmed | Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes |
| title_short | Flow-pattern-based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes |
| title_sort | flow pattern based heat transfer and pressure drop correlations for condensing refrigerants in smooth tubes |
| topic | Time fraction Flow pattern Smooth tube Condensation Heat transfer Pressure drop UCTD |
| url | http://hdl.handle.net/2263/26055 http://upetd.up.ac.za/thesis/available/etd-07042008-181022/ |