本文選題：膜蒸餾 + 熱泵��； 參考：《天津科技大學(xué)》2016年碩士論文

【摘要】：膜蒸餾技術(shù)是一項(xiàng)將蒸餾與膜分離技術(shù)相結(jié)合的新技術(shù),具有常壓中低溫操作、設(shè)備簡單等優(yōu)點(diǎn),在中高濃度廢水處理、超純水制備、熱敏性料液濃縮等方面均可廣泛應(yīng)用。膜蒸餾過程需要外界同時(shí)提供冷熱能對其冷凝液側(cè)冷卻、料液側(cè)加熱,基于熱泵系統(tǒng)可以同時(shí)提供冷熱能的特點(diǎn),將膜蒸餾技術(shù)與熱泵相結(jié)合,為解決單效膜蒸餾系統(tǒng)能耗大的問題,本文將熱泵與多效膜蒸餾技術(shù)集合為熱泵多效膜蒸餾系統(tǒng),并對其性能隨不同參數(shù)的變化規(guī)律進(jìn)行研究。針對四種膜蒸餾技術(shù):直接接觸式膜蒸餾(DCMD)、氣隙式膜蒸餾(AGMD)、氣掃式膜蒸餾(SGMD)、真空式膜蒸餾(VMD)。建立了各自的物理模型,給出了膜通量和造水比的理論方程,并以膜通量、造水比為評價(jià)指標(biāo),對其隨料液溫度、膜冷熱側(cè)溫差、膜孔徑、膜壁厚度的變化規(guī)律進(jìn)行了計(jì)算對比,結(jié)果表明,相同條件下VMD膜通量和造水比最高,但投資偏大;AGMD和SGMD造水比較高但膜通量偏低;DCMD結(jié)構(gòu)簡單,膜通量較大、適宜條件下造水比也較高,具有較強(qiáng)的綜合優(yōu)勢。以DCMD為基礎(chǔ),構(gòu)建了熱泵兩效膜蒸餾系統(tǒng)的物理模型和數(shù)學(xué)模型,編制了計(jì)算軟件,對產(chǎn)水率、造水比、熱泵制熱量和熱泵制熱系數(shù)等性能指標(biāo)隨料液溫度、膜組件膜面積和液體流速的變化規(guī)律進(jìn)行了計(jì)算研究。結(jié)果表明,在一定范圍內(nèi),系統(tǒng)在料液溫度較低時(shí),產(chǎn)水率、造水比等隨著料液溫度近似呈線性增大,當(dāng)料液溫度達(dá)到70℃后,產(chǎn)水率、造水比等繼續(xù)增大,但增幅減小;一定范圍內(nèi),系統(tǒng)產(chǎn)水率、造水比等隨著膜面積的增大而增大,但增幅越來越小;一定范圍內(nèi),系統(tǒng)在料液溫度較高、膜面積較大時(shí)運(yùn)行最好。以上述工作為指導(dǎo),以熱敏料液低溫濃縮為背景,研制了熱泵兩效膜蒸餾實(shí)驗(yàn)裝置,研究了系統(tǒng)工作時(shí)的工況調(diào)整方法和性能指標(biāo)變化規(guī)律,結(jié)果表明,采用輔冷器可顯著改進(jìn)裝置的工況調(diào)整效果,產(chǎn)水率、造水比、熱泵制熱量和熱泵制熱系數(shù)等變化規(guī)律與理論模型計(jì)算結(jié)果基本一致,低溫工況熱泵性能良好,但膜組件的造水比和膜通量較低。
[Abstract]:Membrane distillation is a new technology which combines distillation with membrane separation technology. It has the advantages of normal pressure, medium and low temperature operation, simple equipment and so on. It can be widely used in the treatment of medium and high concentration wastewater, the preparation of ultra-pure water, and the concentration of thermosensitive material liquid. In the process of membrane distillation, the heat and cold energy is provided simultaneously to cool the condensate side and the material side is heated. Based on the characteristics that the heat pump system can provide the heat and cold energy simultaneously, the membrane distillation technology is combined with the heat pump. In order to solve the problem of high energy consumption of single-effect membrane distillation system, the heat pump and multi-effect membrane distillation technology are combined into heat pump multi-effect membrane distillation system in this paper, and its performance changes with different parameters are studied. There are four kinds of membrane distillation technologies: direct contact membrane distillation, air gap membrane distillation, air sweep membrane distillation and vacuum membrane distillation. Their physical models were established and the theoretical equations of membrane flux and water ratio were given. The membrane flux and the ratio of water to water were taken as the evaluation indexes, and the membrane pore size was determined with the temperature of the liquid, the temperature difference of the cold and hot side of the membrane, and the pore size of the membrane. The results show that the membrane flux and water ratio of VMD are the highest under the same conditions, but the investment is higher than that of SGMD, but the structure of membrane flux is simple and the flux of membrane is larger. The ratio of water to water is also high under suitable conditions, and has strong comprehensive advantages. Based on DCMD, the physical model and mathematical model of two-effect membrane distillation system of heat pump are constructed. The calculation software is developed to calculate the performance of heat pump, such as water yield, ratio of water to water, heat capacity of heat pump and heat coefficient of heat pump, etc. The changes of membrane area and liquid velocity of membrane assembly were calculated and studied. The results show that, in a certain range, the water yield and the ratio of water to water increase linearly with the temperature of the feed liquid at a lower temperature. When the temperature reaches 70 鈩，

本文編號：1928098