薄膜蒸餾乃是一種海水淡化技術，用以製造純水，來供應民生與工業用水。而太陽能則是屬於無污染且無虞匱乏的潔淨能源，是目前世界各國的發展重點。本研究即是結合薄膜蒸餾與太陽能源的特點，設計一太陽能平板型氣隔式薄膜蒸發系統，此系統的特色乃是藉由吸收板收集太陽光通量並加熱工作流體，提升冷熱流體的溫度差，以提高薄膜蒸發的效率和純水產率。 本研究分別針對傳統氣隔式薄膜蒸發與新型太陽能氣隔式薄膜蒸發系統做理論模式建立，並根據不同之操作條件與設計參數作體下討論：(一) 流體進口溫度、(二)流體體積流量、(三)氣隔層之厚度、(四)太陽光之入射量等對蒸發液量之影響，並與傳統氣隔式薄膜比較。研究結果顯示，在熱流體溫度較低和流量較小時，蒸發液增加效率較高，在氣隔層厚度越薄時，純水產率較大，且入射量對增加效果也較好，當氣隔層厚度在2.5mm 時，氣隔式薄膜蒸發系統之熱效率最好。 A new design of the solar air gap membrane distillation (Solar AGMD) system is investigated theoretically and experimentally. The theoretical formulations are also developed and the resultant equations are solved by the Newton-Raphson method. The effects of the fluid inlet temperature, volumetric flow rate, air gap thickness and incident solar radiation on the heat transfer efficiency and the productivity of pure water are discussed in this study. The theoretical results indicate that the pure water productivity increases with increasing the inlet temperature of hot fluid, volumetric flow rate and incident solar radiation. Moreover, the best thermal efficiency of the solar AGMD system was obtained as the air gap thickness is 2.5 mm. A comparison of the traditional air gap membrane distillation system (AGMD) and the new solar AGMD system on the pure water productivity are also made. The results show that the solar AGMD system does the better performance than the traditional AGMD system. The experiments of the AGMD and solar AGMD systems are set up to confirm the accuracy of the theoretical predictions. The good agreement is achieved between the theoretical results and the experimental runs in the present study.
