本文選題：太陽能集熱器　切入點：減壓膜蒸餾　出處：《武漢紡織大學》2016年碩士論文　論文類型：學位論文

【摘要】：眾所周知,淡水資源是人類賴以生存和發(fā)展的基礎物質(zhì)之一。然而,隨著社會經(jīng)濟以及現(xiàn)代工業(yè)的不斷發(fā)展,淡水資源的短缺已經(jīng)成為世界性問題。海水淡化作為一種解決淡水資源短缺的重要手段越來越被世界各國所關注。常規(guī)的海水淡化是高能耗產(chǎn)業(yè),但在當今石油資源日益枯竭的威脅下,人類不得不尋求一種綠色可持續(xù)的海水淡化發(fā)展道路。因此,結合可再生能源(如太陽能)等實現(xiàn)海水淡化必將成為解決淡水危機的重要研究方向。膜蒸餾技術(Membrane distillation,MD)是一種將膜技術與熱蒸餾過程結合在一起的新型膜分離技術,由于MD不需要將待處理的液體加熱到沸點以上,因此所需操作溫度更低。將MD過程耦合太陽能集熱技術,利用低品位熱源作為膜蒸餾的能源驅動,是目前膜蒸餾淡化海水研究的一個新熱點,有望成為一種高效廉價的海水脫鹽技術。本文首先用恒溫電加熱水箱作為加熱熱源,以3.5%的NaCl溶液模擬海水,用疏水性聚丙烯(PP)中空纖維膜進行減壓膜蒸餾實驗,重點研究不同進料液溫度、冷側真空度、進料液流量以及進料液濃度對膜通量、截留率、淡水電導率等的影響,從而確定影響實驗系統(tǒng)的最佳反應條件。實驗結果表明,進料液溫度和冷側真空度是影響系統(tǒng)性能的主要因素,其最佳反應條件為:溫度70℃;真空度0.095MPa;其中最大膜通量達到10.31kg/(m2·h);聚丙烯(PP)疏水膜表現(xiàn)出了很好的膜分離功能,截留率均大于99.9%,且淡水的電導率可達10μs/cm以下。其次,在減壓膜蒸餾小試實驗的基礎上,設計構建了一種新型可旋轉的、以太陽能集熱器耦合電加熱的減壓膜蒸餾海水淡化系統(tǒng),考察可旋轉式太陽能集熱裝置的集熱穩(wěn)定性,確定其應用于膜蒸餾實驗的可行性。最后,以經(jīng)過預處理的真實海水在該裝置下進行實驗,考察了一個工作日內(nèi)太陽能海水淡化裝置的工作狀態(tài),并對該新型裝置下的海水淡化實驗過程與結論進行分析,總結運行過程中的缺陷和不足,為將來構建太陽能膜蒸餾海水淡化中試系統(tǒng)提供一定的參考和依據(jù)。
[Abstract]:As we all know, freshwater resources are one of the basic materials for human survival and development. However, with the development of social economy and modern industry, The shortage of fresh water resources has become a worldwide problem. As an important means to solve the shortage of fresh water resources, seawater desalination has been paid more and more attention by many countries all over the world. Conventional desalination is a high energy consumption industry. However, under the threat of increasing depletion of petroleum resources, human beings have to seek a green and sustainable way to develop seawater desalination. Seawater desalination with renewable energy (such as solar energy) will become an important research direction to solve the freshwater crisis. Membrane distillation (Membrane distillation) is a new membrane separation technology which combines membrane technology with thermal distillation process. Because MD does not need to heat the liquid to the boiling point, so the operating temperature is lower. The MD process is coupled with solar energy collection technology, and the low-grade heat source is used as the energy source for membrane distillation. At present, membrane distillation desalination is a new research hotspot, which is expected to become an efficient and cheap desalination technology. In this paper, the constant temperature electric heating tank is used as the heating heat source, and the 3.5% NaCl solution is used to simulate the sea water. The experiment of vacuum membrane distillation with hydrophobic polypropylene (PP) hollow fiber membrane was carried out. The effects of different feed temperature, cold side vacuum degree, feed liquid flow rate and feed liquid concentration on membrane flux, rejection rate, fresh water conductivity and so on were studied. The experimental results show that the temperature of feed liquid and the vacuum degree of cold side are the main factors affecting the performance of the system, and the optimum reaction conditions are as follows: temperature 70 鈩，

本文編號：1588824