本文選題：光催化 + 二氧化碳還原��； 參考：《華北電力大學(xué)》2015年碩士論文

【摘要】：能源危機(jī)和溫室效應(yīng)制約著人類的發(fā)展。利用太陽光的光催化還原CO2技術(shù)既能控制溫室氣體排放,又可產(chǎn)生燃料甲醇,富有發(fā)展?jié)摿�。作為光催化還原CO2反應(yīng)的載體,蜂窩光纖反應(yīng)器因其反應(yīng)速率高、傳質(zhì)能力強(qiáng)備受關(guān)注。以蜂窩光纖反應(yīng)器為對象,以數(shù)值模擬為手段,選擇合適的反應(yīng)動(dòng)力學(xué)模型、流動(dòng)擴(kuò)散模型等,開展研究。數(shù)值模擬結(jié)果與已有實(shí)驗(yàn)數(shù)據(jù)吻合,證明數(shù)值模擬的可行性。將多根光纖嵌入單個(gè)反應(yīng)通道并改變光源位置,提出多光纖蜂窩反應(yīng)器。對已有光強(qiáng)分布模型進(jìn)行分析和推導(dǎo),得出新的光強(qiáng)分布公式。通過數(shù)值實(shí)驗(yàn),得出CH30H濃度與光纖位置和運(yùn)行參數(shù)的變化關(guān)系。隨著光纖和反應(yīng)器中心距離、輸入光強(qiáng)和水蒸氣濃度的增加,CH30H平均濃度增加。但隨著入口流速的增加,CH30H平均濃度下降,二者呈反比關(guān)系。多光纖蜂窩反應(yīng)器的CH30H最高出口平均濃度為2.32×10-5 mol·m-3,與蜂窩光纖反應(yīng)器的結(jié)果1.770×10-5mol·m-3相比,提高了31.1%。多光纖蜂窩反應(yīng)器的最大轉(zhuǎn)化效率和量子效率分別為0.235μmol·g-1·h-1和0.0177%,均高于蜂窩光纖反應(yīng)器(0.16μmol·g-1·h-1和0.012%)。增加蜂窩光纖反應(yīng)器的反應(yīng)層數(shù)以擴(kuò)大反應(yīng)表面積,得到多反應(yīng)層蜂窩反應(yīng)器。結(jié)合多光纖模型,繼續(xù)優(yōu)化得到多反應(yīng)層多光纖蜂窩反應(yīng)器。提出到達(dá)反應(yīng)面的光功率和單位輸入功率的產(chǎn)物速率等參數(shù),以更好地對比幾種結(jié)構(gòu)的性能。通過光強(qiáng)的積分得到光功率,并發(fā)現(xiàn)入口流速和光纖數(shù)量一定時(shí),光功率和CH30H濃度呈線性關(guān)系。兩種優(yōu)化的結(jié)構(gòu)中,出口CH3OH濃度為3.004×10-5 mol·m-3和3.685×10-5 mol·m-3,分別增加了69.7%和108.2%。光功率的傳輸效率最大為2.297%,最高的CH30H產(chǎn)率為3.018×10-12mol·s-1.W-1。通過分析不同半徑和流速下的濃度場、產(chǎn)物出口濃度和光強(qiáng),得出多光纖多反應(yīng)層蜂窩反應(yīng)器的優(yōu)化結(jié)構(gòu)為：中層管直徑12 mm、長度50 mm。
[Abstract]:The energy crisis and the greenhouse effect restrict the development of human beings. The photocatalytic reduction of CO2 by solar light can not only control the emission of greenhouse gases, but also produce fuel methanol, which has a potential for development. As a carrier for photocatalytic reduction of CO2 reaction, the honeycomb fiber reactor has attracted much attention because of its high reaction rate and high mass transfer capacity. The results of the numerical simulation are consistent with the existing experimental data, which proves the feasibility of the numerical simulation. Multiple optical fibers are embedded in a single reaction channel and the location of the light source is changed, and the existing optical fiber honeycomb reactor is proposed. The distribution model is analyzed and deduced, and a new light intensity distribution formula is obtained. Through numerical experiments, the relationship between CH30H concentration and optical fiber position and operating parameters is obtained. With the center distance of the fiber and reactor, the intensity of input light and the concentration of water vapor increase, and the average concentration of CH30H increases. With the increase of the inlet velocity, the average concentration of CH30H is under the increase of the inlet velocity. The average concentration of the highest CH30H outlet of the multi fiber honeycomb reactor is 2.32 * 10-5 mol. M-3. Compared with the result of the honeycomb fiber reactor 1.770 x 10-5mol. M-3, the maximum conversion efficiency and the quantum efficiency of the 31.1%. multi fiber honeycomb reactor are 0.235 Mu mol, g-1. H-1 and 0.0177% respectively, which are higher than those of the honeycomb light. Fiber reactor (0.16 mol. G-1. H-1 and 0.012%). Increase the number of reaction layers of the honeycomb fiber reactor to enlarge the reaction surface area and obtain the multi reaction layer honeycomb reactor. Combined with multi fiber model, the multi reaction layer multi fiber honeycomb reactor is continuously optimized. The parameters of the light power reaching the reacting surface and the rate of product of the unit input power are proposed. To better compare the performance of several structures. The light power is obtained through the integration of light intensity. The linear relationship between the light power and the CH30H concentration is found when the inlet velocity and the number of fibers are fixed. In the two optimized structures, the export CH3OH concentration is 3.004 * 10-5 mol. M-3 and 3.685 x 10-5 mol. M-3, increasing the transmission of 69.7% and 108.2%. light power respectively. The maximum efficiency of transmission is 2.297%, the highest CH30H yield is 3.018 x 10-12mol. S-1.W-1., through the analysis of the concentration field at different radius and flow rate, the concentration of the product and the light intensity, the optimum structure of the multi fiber multi reaction layer honeycomb reactor is that the diameter of the middle layer is 12 mm, and the length is 50 mm..
【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN253

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相關(guān)期刊論文 前2條

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本文編號：2032261