太陽能輔助式薄膜蒸餾於海水淡化之應用研究

The Study of Solar Assisted Membrane Distillation on Seawater Desalination

陳宗慶(Tsung-Ching Chen)

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博士班/博士(2010年)

https://doi.org/10.6846/TKU.2010.00033

摘要

太陽能輔助式薄膜蒸餾海水淡化系統是一套節能的系統，係將太陽能集熱設備與薄膜蒸餾系統作一結合，並利用源源不絕的太陽熱能作為薄膜分離驅動力的來源。太陽熱能應用於薄膜蒸餾系統有兩個方式，即(一)間接式加熱程序，其特點即是將太陽能透過集熱設備收集並加以儲存，再間接地提供予薄膜蒸餾單元利用；(二)直接式加熱程序：即將太陽能集熱設備與薄膜蒸餾設備結合，在平板式薄膜蒸餾設備中裝設一具有太陽輻射吸收功能之吸收板，可補充薄膜蒸餾程序中之熱量損失，提高純水產能，同時，對於節省設備空間有相當大的幫助。本研究針對太陽能輔助式薄膜蒸餾之主要設備進行效率改善研究，研究對象包括:(1)超薄通道式太陽能集熱器；(2)直接接觸式薄膜蒸餾系統；(3)雙膜型直接接觸式薄膜蒸餾系統；(4) 直接輔助式太陽能薄膜蒸餾系統。本研究的研究目的為：(1)設計超薄通道式太陽能集熱器，以提升傳統太陽能集熱器之集熱較率；(2)以二維數學模型針對不同薄膜蒸餾設備的熱量與質量傳送機制進行研究，並以實驗分析的方法驗證數學模式的正確性，探討設計參數及操作條件對於集熱器之集熱效率提升百分率和薄膜蒸餾系統之流體溫度分佈、溫度極化現象及純水透膜通量提升百分率進行研究。研究結果顯示，超薄通道式太陽能集熱器、直接接觸式薄膜蒸餾系統、雙膜型直接接觸式薄膜蒸餾系統及直接輔助式太陽能薄膜蒸餾系統之理論值與實驗值的平均相對誤差為1.33 %、5.98 %、5.86 %及4.84 %。本研究以開發低流體流速設備為主，除了可以降低操作成本外，經由新穎的改善策略可提升設備效能並得到令人滿意的熱量及質量傳送效率改善效果。

關鍵字

薄膜蒸餾 ； 太陽能集熱器 ； 透膜通量 ； 效率提升

並列摘要

The solar heat assisted membrane seawater desalination system is technically and economically feasible, which is constructed of solar collectors and membrane distillation device for energy saving water purification. The diving force of separation in membrane distillation device is supplied by infinite resources of solar radiation. Solar desalination systems are classified into two categories, i.e. direct and indirect collector systems. There are some advantages for the direct indirect solar heat driven systems (1) the direct solar heat system integrates the solar absorber as an additional heat supply source and membrane distillation process into a small-scale unit which uses the solar radiation as the heat source to produce high purity water; (2) the hot brine is indirectly preheated by the solar heating system to prevent equipment fouling and the maintenance costs of solar collectors and hot water storages are low, respectively. The purposes of this study are (1) to study new design of ultra-thin channel solar water heater, direct contact membrane distillation, dual films membrane distillation, immediate solar assisted membrane distillation systems with mathematical modeling and experimental studies; (2) to develop a two-dimensional mathematical model and propose a general numerical method for solving this complex mathematical model in predicting pure water productivity of membrane distillation systems; (3) to study the collector efficiency improvement of solar collector and the effect of temperature distributions, temperature polarization and pure water productivity improvement on the membrane distillation systems. The results show that the agreement between the experimental results and theoretical prediction are fairly good.

並列關鍵字

membrane distillation ； solar collector ； transmembrane flux ； efficiency improvement ； temperature polarization

參考文獻

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