碩士 / 國立臺北科技大學 / 能源與冷凍空調工程系碩士班 / 96 / This study investigates a new enhanced boiling surface, which is made by wrapping wire mesh on finned tubes. Pool boiling performance of the new enhanced tubes has been tested in Refrigerant-134a at 5, 10, 20, and 26.67oC saturation temperatures. Brass or copper mesh of 80, 100, or 120 meshes per inch was wrapped on finned tubes of 42, 50, or 60 FPI (fins per inch). The fin heights were either 0.2 mm or 0.4 mm. The test results show that the mesh covered fin tubes significantly enhanced the boiling performance by forming many pores of proper sizes on the surface and sustaining vapor in the tunnels formed by the mesh and fins. The enhanced surface formed by single layer of #100 (100 mesh per inch) brass mesh results in the best boiling performance at 5, and 10oC. However, the double layers of #80 copper mesh results in the best performance at 26.67oC. The best surface was made by wrapping two layers of # 80 copper mesh on the 0.4 mm fin height, 60 FPI tube. The boiling heat transfer coefficient of this surface is enhanced by 10.93 folds in average as compared with the smooth surface at 26.6oC saturation temperature. The enhancement ratio decreases as the saturation temperature decreases from 7.53 folds at 10oC to 6.16 folds at 5oC.
| Identifer | oai:union.ndltd.org:TW/096TIT05703048 |
| Date | January 2008 |
| Creators | Hao-Lin Huang, 黃浩林 |
| Contributors | 簡良翰 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 75 |
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