碩士 / 國立高雄海洋科技大學 / 輪機工程研究所 / 99 / Abstract
The purpose of this study is to investigate the heat transfer as well as friction characteristics of a double pipe heat exchanger with internal fins. A counterflow arrangement is made for the hot water and cold water which serve as the working fluids. Smooth, four-fin, and eight-fin tubes are tested with an inclination angle of 0°, 30°, 60° and 90° in the test. In addition, with a well-stirred design, the hot water is kept around 70 ℃ in the hot bathing constant-temperature reservoir whereas the cold water temperature is set at 20 ℃. The temperature and pressure differences are recorded as the working fluids are pumped through the test unit. For a fully developed flow, the tested Reynolds number ranges from 250 to 750. The effects of flow velocities and fin numbers on the Nusselt number and friction factor of the tested heat exchangers are determined. It is shown that the heat transfer characteristics of the exchanger with fins is better than that with smooth tube. The more the fins installed in exchanger, the better the heat transfer performance will be. In addition, the inclination of the heat exchanger will enhance the heat transfer especially in natural convection.
| Identifer | oai:union.ndltd.org:TW/098NKIM8484006 |
| Date | January 2010 |
| Creators | Chi-yu,Liu, 劉起宇 |
| Contributors | Yeh, R.H., 葉榮華 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 56 |
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