碩士 / 逢甲大學 / 機械工程學所 / 92 / Abstract
The optimal fin shape profile of a three-dimensional finned-tube heat exchanger was studied with numerical method in this research. When the fluid flows through the finned-tube heat exchanger at a certain speed, heat flux on the fin varies with the position, and the optimal fin shape profile was non-circular curve. FLUENT, a canned software, was utilized for numerical simulation in the study to investigate the optimal fin shape profile effects of different materials, including copper, aluminum and steel as well as the thickness and the interval of fins under various velocities of flows. Moreover, the issue of how much material saved by the optimal fin shape profile was also discussed in the article.
Numerical results indicate the optimal fin shape profile is not a round ring indeed, and the optimal fin shape profile near the tube does not change after altering the primary fin shape. When the velocity of flow increases, the optimal fin shape does not change, but shrinks towards the tube. As the thermal conductivity coefficient of the copper-based fin is the greatest, its optimal shape is the biggest as well. The optimal fin shape does not change when the fin gets thicker; however, the area expands outward. As the interval of the fin diminishes, the optimal shape turns to be flat and long. The optimal fin shape profile of a finned-tube heat exchanger is truly affected by the velocity, material of fin, thickness of fin and interval of fin; nevertheless, the influence is merely limited to the size rather than the shape of the optimal shape. A comparison of heat transfer rate between an optimal fin-shaped heat exchanger and a heat exchanger on the market shows that the iron-based fin can save 25% material with a reduced heat transfer rate by 4%, which reveals the optimal copper-based fin shape with the highest heat transfer rate does not save much material. The result of this paper can be a great contribution to the exploration of the optimal fin shape profile of the heat exchanger when served to be a reference of fin shape design for the developers and designers of heat exchangers.
| Identifer | oai:union.ndltd.org:TW/092FCU05489063 |
| Date | January 2004 |
| Creators | Hung-Chia Wang, 王宏加 |
| Contributors | Wen-Jeng Chang, 張文政 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 103 |
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