碩士 / 國立海洋大學 / 機械與輪機工程學系 / 89 / In this paper, an induced Wind tunnel was used to measure the thermal characteristics of air conditioner below the dew-point temperature and so-called wet coil. Three plain plates and four slit-fin heat exchangers were tested with different fin pitch, row number, and fin type. During the measurements, the ice water temperature at the inlet were maintained at 7.5℃ and with a flow rate of 6L/min in the tube side. Outside the tube, the frontal velocity of air was varied in the range from 0.33 to 1.25 m/s. On the other hand, the water side, the ice water temperature was changed in the range from 5.5 to 12.5℃ with a constant frontal velocity at 0.33 m/s. The objective of the present study is to investigate the total heat transfer rate including sensible and latent heat transfer. Furthermore, sensible heat factor and the ability of dehumidity are also calculated.
The results indicate that the latent heat transfer plays an important role in the overall heat transfer in all cases. The heat transfer increases with air inlet velocity and fin numbers. In addition, the sensible heat factor and dehumidity is found to increase with the inlet velocity of air in the wet coil. The heat transfer rate and dehumidity increase when the temperature at the inlet ice water decreases. Also, the sensible heat factor decreases when the inlet temperature of ice water decreases.
In the experiments, the data were made to compare with the results of the other previous documents. Because the frontal velocity was kept in the range from 0.33 to 1.25m/s, and Reynold Number is less than 1200. The heat transfer rate and dehumidity increase with the row number and fin pitch. The heat transfer rate and dehumidity of the slit fin type are higher than those measured from the plain fin type heat exchanger. The sensible heat factor decreases while the row number increases.
We wish to present useful information about fin-and-tube heat exchangers through the present experiments. Further, it can promote the efficiency of exchangers with the knowledge of the characteristics of heat transfer and air condition of plain and slit fin-and-tube heat exchangers.
| Identifer | oai:union.ndltd.org:TW/089NTOU0491005 |
| Date | January 2001 |
| Creators | He Jau-Cheng, 賀照誠 |
| Contributors | Liaw Shih-Pin, 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 | 86 |
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