碩士 / 元智大學 / 機械工程研究所 / 86 / In the present study , ten louver and four plain and twenty-two wavy fin-and-tube feat exchangers were tested. In the louvers and plains , the corresponding longitudinal tube pitches for the test samples were 19.05 and 22 mm, and the nominal tube diameter for the test samples is 9.52 mm. For plain fin pattern, the effect of longitudinal tube pitch on the air-side performance is negligible whereas the heat transfer performance increases with decrease of fin pitch. For louver fin geometry, both longitudinal tube pitch and fin pitch shows very small effect on the heat transfer performance. However, it is found that the heat transfer coefficients for Fp = 1.78 mm are approximately 0-10% higher than those of Fp = 1.21 nun and Fp = 2.42 mm. In addition, compared with Pl = 19.05 mm, significant increase of friction factors were observed for the louver fin pattern.
In the wavy , the effects of the number of tube rows , fin pitch , and edge-corrugation on the air-side performances were examined. It is found that the heat transfer characteristics were strongly related to the corrugation angle , and the ratio of waffle height and wave length. In addition , the effect of edge-corrugation had negligible effect on the air-side performance. The proposed correlation can describe 93﹪of j within 10﹪, and can correlate 91.8﹪of the friction factor within 10﹪.
| Identifer | oai:union.ndltd.org:TW/086YZU00489010 |
| Creators | 李錡專 |
| Contributors | , 蘇艾, 張昌財 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 68 |
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