本研究利用計算流體力學(Computational Fluid Dynamics, CFD)模擬探討薄膜接觸器應用於鹽水脫鹽與二氧化碳吸收之流力與熱質傳特性。薄膜接觸器使用多孔疏水性膜且模組型式包括空通道與具網狀間隔物通道。本研究使用FLUENT軟體之層流模式與VOF(Volume of Fluid)多相模式，薄膜為可滲透邊界條件。模式之驗證是利用文獻實驗數據且獲得相當接近之結果。 具間隔物模組之流力與熱質傳特性皆會受到間隔物配置之影響，而呈現上下震盪之變化，其壓降、熱傳係數與質傳係數均高於空通道。間隔物通道與空通道之濃度邊界層厚度分別約為1 mm與2-4 mm。使用具間隔物通道可大幅提升鹽水脫鹽系統與碳酸丙烯酯之二氧化碳物理性吸收系統之質傳通量。間隔物通道之水利損耗遠高於空通道，後者接近平板通道關聯式預測值。間隔物與空通道之熱傳係數與質傳係數均與文獻報導關聯式之預測值有很大偏差。 In this thesis, the fluid flow, heat and mass transfer characteristics in the membrane contactors for desalination and carbon dioxide physical absorption with propylene carbonate are studied using computational fluid dynamics (CFD) simulation. For desalination, the membrane modules are direct contact type. The membrane contactors simulated use hydrophobic membranes and either empty or spacer-filled channels. The laminar flow model and Volume of Fluid (VOF) multiphase model in FLUENT are employed with the membranes defined as permeable boundary conditions. The model simulation results are fairly close to the literature experimental data The fluid flow, mass and heat transfer characteristics of spacer-filled channels show fluctuating patterns corresponding to the spacer configurations. The pressure drop, heat and mass transfer coefficients of spacer-filled channels are all higher than the empty channels. The concentration boundary layer thicknesses of spacer-filled and empty channels are approximately 1 mm and 2-4 mm, respectively. For both desalination and carbon dioxide absorption systems, the spacers significantly enhance the transmembrane mass fluxes. The hydraulic power consumptions of spacer-filled channels are much higher than the empty channels, which are close to the correlation for parallel-plate channels. The heat and mass transfer coefficients of both spacer-filled and empty channels are not close to the literature reported correlations.
