垂直圓管中二元非共沸混合氣體的強制對流凝結是本篇所要探討的主題，
以理論模式分析描述其冷凝情形，並佐以二元非共沸混合氣體在分離式兩
相虹吸熱管的實驗驗證其冷凝趨勢。垂直冷凝管入口為層流之混合氣體，
在管壁有固定熱通量時開始凝結，計算時假設管壁為均勻熱通量，忽略冷
凝膜的表面張力及漣漪效應，利用邊界層理論來處理氣相統御方程式，並
且以修正的Nusselt解來處理液相統御方程式，計算出二元非共沸混合氣
體的冷凝率、熱傳係數、溫度分布及速度分布。本理論模式所解得的熱傳
係數、壓力及溫度分布之數值解和實驗的趨勢是相吻合的。由於圓管中二
元非共沸混合氣體的冷凝流場相當繁複，且文獻上對理論的探討仍不多見
，本理論模式所計算的結果可作為熱交換器設計時之參考。

The subject of this thesis is to investigate forced convective
filmwise condensation of non-azeotropic binary mixtures inside
a vertical tube. The numerical results are verified by the ex-
perimental data obtained in a two phase closed-loop thermosy-
phon which using non-azeotropic binary as working fluid. The
gas mixtures at the vertical tube inlet are liminar and be- gin
condensing under the condition that the heat flux at wall is
uniform and neglects the surface tension and wavy effect of
liquid film, the condensation rate, heat transfer coefficient,
temperature and velocity distributions in binary mixtures are
analyzed using boundary layer theory in vapor phase and
modified Nusselt solution in liquid film for the governing
equations. The trends of numerical results obtained from
present model such as heat transfer coefficient, pressure and
temperature distribu- tions are in good agreement compared with
those of experimental data. Due to the complicated flow fields
of condensation of non- azeotropic binary mixtures in pipes and
the lack of theoretical study in published literature,the
present model can serve as a useful guide in the design of heat
exchangers.