碩士 / 國立海洋大學 / 機械與輪機工程學系 / 87 / Abstract
In the experiment, an induced Wind tunnel was used to measure thermal and hydrodynamic characteristics for the dry coil. Seven difficult plate fin and tube heat exchangers were conducted with row number and fin pitch varied parametrically. During the meas- urements，the water inlet temperature and flow rate were maintained at 60℃ and 5 L/min in the tube side. However, in the fin side, the air frontal velocity was kept in the range from 0.3 to 1.8 m/s. The objective of the present study is to investigate the heat duty, overall heat coefficient, pressure drop, Colburn factor, and fr- iction factor.
The results indicate that the pressure drop and heat transfer increase with air inlet velocity and fin numbers, and the overall heat coefficient increases with air inlet velocity. The Colburn factor j and friction factor f are compared with other investigations, and good agreement is obtained. When Reynolds number is less than 1200,the influence of row number is significant for Colburn factor, and Colburn factor j decreases with the increase of row number. The influence of row number is neglectable for friction factor f. In addition, when the row number is equal to one or two, the change of fin pitch shows a strong dependence
on j and f. The values of Colburn factor and friction factor decrease with the increase of fin pitch, and the influence of fin
pitch decreases with increasing of row numbers.
We wish to present useful information about fin and tube heat exchangers through this experiment；further, it can promote the efficiency of exchangers with the knowledge of the charact- eristics of heat transfer and pressure drop of fin-and-tube heat exchangers.
| Identifer | oai:union.ndltd.org:TW/087NTOU0491006 |
| Date | January 1999 |
| Creators | Huang Ta Yi, 黃大益 |
| Contributors | S.P.Liaw, 廖世平 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 62 |
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