碩士 / 逢甲大學 / 機械工程學所 / 91 / ABSTRACT
The three-dimensional fluid flow in a plate finned oval tube heat exchanger with vortex generator was studied with the SIMPLE algorithm method in addition to an understanding of heat transfer properties and pressure drop. The result of local heat transfer coefficient was analyzed directly and compared with the convection heat transfer coefficient obtained by the conjugate gradient method. This approach was to check the accuracy of the convection heat transfer coefficient in a plate finned oval tube heat exchanger with vortex generator via applying the reverse algorithm method. After exploring the impact upon heat transfer and pressure drop imposed by parameters of various plate finned tubes (circular, oval) heat exchangers with vortex generator such as the number, the position and the shape, etc., it was found that heat transfer effect of fin-tube heat exchanger with a circular tube without vortex generator was better than that with an oval tube; however, higher pressure drop was resulted. When the vortex generator was installed in the front of the tube on both sides, heat convection and transfer effect of an oval tube is better than that of a circular tube and pressure drop of the former is lower as well. Nevertheless, as the vortex generator was placed in the rear of the tube on both sides, heat convection and transfer effect of an oval tube is worse than that of a circular tube despite pressure drop of the former is still lower than that of the latter. From the perspective of the number of vortex generators, it was discovered that the more vortex generators were placed, the better the heat convection and transfer effect with greater pressure drop. A triangular winged vortex generator had the most significant performance of boosting heat transfer effect for a plate finned tube heat exchanger. Upon comparison of the results, it was found that the conjugate gradient method could predict the convection heat transfer coefficient accurately and rapidly for a plate finned oval tube heat exchanger. The results concluded from this article can make great contributions for people who expect to have an in-depth understanding about pressure drop of fluid flow and convection heat transfer coefficient for a plate finned oval tube heat exchanger. The data obtained may serve as a reference of complete detailed design information for heat exchanger developers and designers.
| Identifer | oai:union.ndltd.org:TW/091FCU05489010 |
| Date | January 2003 |
| Creators | Cheng-chung Chang, 張正忠 |
| 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 | 115 |
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