碩士 / 國立勤益科技大學 / 冷凍空調系 / 102 / The effects of flat end plates on the louver fin-and-tube heat exchanger are studied by numerical simulation. The heat transfer and flow field including the flow efficiency and by-pass factors of the flow under different wind speed in the heat exchangers of 3, 4, 5, and 7 fins and two end plates are shown in the results. The flow field in the heat exchanger channel including the duct and louver directed streams is also shown in the results.
The results show that the end plates affect the air volume between fins and the louver-directed flow, the end plates lead to the different heat transfer rate in each fin. The channel near the end plates have smaller air flow by the resistant of the plane end plate to the louver-directed flow, which decrease the fin heat transfer neighboring on it. The heat transfer reduction effect is more evident in the low wind speed. The fins in the middle of the heat exchanger have higher heat transfer due to the increasing air flow directed from the channel near the end plates.
The results show that increasing the numbers of the fin between the end plates can make the heat transfer rate of the middle fin in the heat exchanger approaches the results of the ideal fin with periodic boundary conditions which used in the most literatures. But it is seems that 7 fins used in this research is still not enough to simulate the periodic ideal fin, it still has about 13% difference. The research could be a reference to the experimental model design of louver fin-and-tube heat exchangers.
| Identifer | oai:union.ndltd.org:TW/102NCIT5680012 |
| Date | January 2014 |
| Creators | Chen,Han-Chiang, 陳漢強 |
| Contributors | Hsieh,Wen-Chien, 謝文健 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 96 |
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