碩士 / 國立高雄應用科技大學 / 機械與精密工程研究所 / 96 / Because of the evaporator usually use in inside and outside the very great environment of the difference in temperature. Therefore, the Humidity in the air will condense the frost on evaporator surface, even become the ice. And then creates the thermal resistance. The liquid nitrogen evaporates through the evaporator. Influence the liquid nitrogen to absorb the heat evaporation and become superheated vapor factor to have very much. The factor include the evaporator several structure and material of the machine; and the system-pressure, the thermodynamic properties, the mass flow rate, the quality, the friction factor and the phase-change inside tube and the environment temperature, the humidity, the thermal radiation, the frost thickness, the sensible heat and the latent heat outside tube. These factors can affect heat transfer efficiency of the evaporator. The text used finite volume method. It analyzes the effect of heat transfer of the finned-tube evaporator. The theorem includes the conservation of mass, the conservation of energy, the Bernoulli’s law and the thermal resistance. After the liquid nitrogen flows in the evaporator discussion the entire heat transfer phenomenon. The application runge-kutta method and curve fitting method increases restrains on the precision and the computation speed. The establishment experiment system verifies the analysis program accurately. By the result demonstrated the analysis program and the experimental curve tendency extremely tallies. The simulation method selects the steady state, in view of some condition parameters forecast evaporates the result. Provides designer's in design reference, achieved reduces the cost to be prompt.
| Identifer | oai:union.ndltd.org:TW/096KUAS0693050 |
| Date | January 2008 |
| Creators | Chung Qua Lin, 林全貴 |
| Contributors | Shun Ching Lee, 李順晴 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 83 |
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