碩士 / 國立成功大學 / 機械工程學系碩博士班 / 92 / The numerical analysis was carried out to study the 3- D heat transfer and flow in finned tube heat exchanger of Air-cooled condenser. Three kinds of major/mirror axis ratios (2.5、2.8 and 3) are examined for the elliptic finned-tube heat exchangers and the results are also compared with the corresponding circular finned-tube having the same perimeter. Numerical simulation was performed by 3-D turbulence analysis with conjugated heat transfer and fluid flow. The numerical results for the temperature、pressure 、Nusselt number and fanning friction factor at various inlet frontal velocities(1~5 m/s) are shown and compared with the available experimental data.
The numerical result indicated that the pressure drop of circular finned-tube heat exchanger is 3 times of elliptic finned-tube heat exchanger, while the heat transfer coefficient of circular finned-tube is 1.1 times of elliptic finned-tube. The heat transfer coefficient per unit of pressure drop for elliptic finned-tube(Ar = 3.1) is 1.08 times of elliptic finned-tube(Ar = 2.8) 、1.24 times of elliptic finned-tube(Ar = 2.5) and 2.6 times of circular finned-tube.
| Identifer | oai:union.ndltd.org:TW/092NCKU5490039 |
| Date | January 2004 |
| Creators | Hong-wun Li, 李宏文 |
| Contributors | Jiin-Yuh Jang, 張錦裕 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 71 |
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