嵌入W型碳纖維板於直接接觸式薄膜蒸餾系統之理論與實驗研究

Theoretical and experimental studies of direct contact membrane distillation modules with inserting w-shaped carbon-fiber channels

賴靖元(Jing-Yuan Lai)

指導教授 ： 何啟東

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2017年)

https://doi.org/10.6846/TKU.2017.00039

摘要

薄膜蒸餾海水淡化用來製造純水提供民生及工業使用，因其優點特色為具有裝置簡潔、低能耗、可模組化、高介面面積等，為近來廣受重視的一種技術。然而，薄膜蒸餾因模組通道限制，對於系統產能有相當顯著的影響，此現象越明顯則產能相對低落。
本研究針對薄膜蒸餾之主要設備進行效率改善的研究，目的為：(1)設計新型紊流促進因子(Eddy promoter) ，以求有效改善系統內部的溫度極化現象進而提升系統產能，並歸納出一經驗公式，描述此型式的紊流促進因子對於通道內部熱對流效應的影響；(2)藉由一維數學模型針對薄膜蒸餾設備的熱量與質量傳送機制進行研究，配合實驗分析以驗證經驗公式與數學模型的正確性；(3)探討設計參數及操作條件對於薄膜蒸餾系統之流體溫度分佈、溫度極化現象、純水透膜通量增加百分率與水力損耗提升百分率的影響。
研究結果顯示，嵌入W型碳纖維直接接觸式薄膜蒸餾系統之理論值與實驗值的相對誤差總平均為9.17 %，而本研究設定新型擾流因子能夠有效的提升系統透膜通量，最高可達到單位面積的34.17%的增益。本研究以操作在低體積流率之設備為主，除了有效利用通道內熱側流體以降低操作成本外，經由改善後的設計可提升設備效能並得到增加透膜通量總產量的效果。

關鍵字

直接接觸式薄膜蒸餾 ； 透膜通量 ； 溫度極化 ； 碳纖維板 ； 水力角度

並列摘要

The modeling equations for predicting distillate flux in the flat-plate direct contact membrane distillation (DCMD) module with inserting W-shaped carbon-fiber spacers of various hydrodynamic angles in flow channels were developed theoretical and experimentally. The pure water productivity and temperature distributions of both hot and cold feed streams are represented graphically with the volumetric flow rate, inlet saline temperature as parameters, and the experimental data was incorporated with the slot opening of the spacers and hydrodynamic angle as parameters to validate the theoretical predictions. A description of the average Nusselt number was made to evolve a correlation for a heat transfer coefficient correction factor in incorporating with experimental data. The effects of operating and design parameters such as volumetric flow rate, slot opening and hydrodynamic angle of the spacers, and inlet saline temperature on pure water productivity and production energy efficiency were also delineated.

並列關鍵字

Direct contact membrane distillation ； Permeate flux ； Temperature polarization ； Carbon-fiber spacers ； Hydrodynamic angles

參考文獻

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