碩士 / 國立清華大學 / 動力機械工程學系 / 105 / This study investigates the airside performance and friction factor of 12 samples of smooth wavy fin-and-tube heat exchanger. All samples have large diameter (D_C=16.3mm) amount of tube rows (2, 4, 6 row), spacing of fin pitches (3 and 1.8mm), and cross sections (circular and oval). It is found that the heat transfer coefficient of circular samples increase as the amount of tube rows increases from N=2 to N=4. For oval samples, as the amounts of tube rows increase, the heat transfer coefficient of 3mm-spacing samples increase while the 1.8mm-spacing samples decrease.
For all samples, the effect of tube row on friction factors is negligible. The circular samples have higher friction factor as the fin-pitch spacing increases, and as the Reynolds number increases, the increase of friction factor with pitch spacing also accelerates.
The 3mm-pitch-spacing oval samples with N=2 improve heat transfer performance by 19.8% while decrease the pressure drop by 8.1%.
| Identifer | oai:union.ndltd.org:TW/105NTHU5311101 |
| Date | January 2017 |
| Creators | Hsu, Chen-Chieh, 徐振傑 |
| Contributors | Sheu, Wen-Jenn, Wang, Chi-Chuan, 許文震, 王啟川 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 52 |
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