碩士 / 國立臺灣海洋大學 / 機械與機電工程學系 / 101 / The objective of this study is to investigate the thermal characteristics of fin-tube air heaters powered by Dowtherm oil, and the outlet is used in heating a drying chamber. The Reynolds number, heat transfer coefficients inside and outside the tube are calculated, and hence the heat transfer area and the number of tubes are readily obtained. In addition, the layout of the tubes is studied accompanied with the pressure drop required. Secondly, according to the amount of heat loss and ventilation rate, the temporal variation of temperature in drying chamber is presented.
The temperature of the drying chamber was found to change with the dimension of the drying chamber, such as thicknesses in different layer of the inner frame, insulating layer and outer frame. The rate of heat loss as well as the ventilation influences the ultimate temperature. The above mentioned parameters are studied in this thesis.
The computer program was coded in Excel language which developed by Microsoft. First of all, input information includes the detailed structure size and operating conditions. The temperature dependent physical properties are inquired from the date base sheets. The preliminary structure of air heater is suggested. Coupled to the drying chamber, through a series of numerical analysis, the temperature at the exit of drying chamber can be estimated in each time step. Finally, the variation of temperature versus time is plotted in diagrams to assess whether the size of the heat exchanger design is satisfied.
| Identifer | oai:union.ndltd.org:TW/101NTOU5491015 |
| Date | January 2013 |
| Creators | Ci-Yuan Siao, 蕭棨元 |
| Contributors | Shih-Pin 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 | 53 |
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