本文選題：噴射型內(nèi)環(huán)流反應(yīng)器 + 氣液鼓泡流�。� 參考：《浙江大學(xué)》2017年碩士論文

【摘要】：內(nèi)環(huán)流反應(yīng)器廣泛的應(yīng)用于重質(zhì)油加氫、生物發(fā)酵、污水處理等化工過程。工業(yè)上普遍使用帶均勻分布器的內(nèi)環(huán)流反應(yīng)器,反應(yīng)器內(nèi)部氣泡尺寸均勻,氣含率差異不大,循環(huán)速度有限。使用氣液噴射器可產(chǎn)生不同尺寸的大小氣泡,大氣泡加強(qiáng)流體的湍動(dòng),有效地克服傳統(tǒng)內(nèi)環(huán)流反應(yīng)器循環(huán)速度不足的缺陷,小氣泡同時(shí)可以促進(jìn)氣液傳質(zhì)。將噴射型分布器和內(nèi)環(huán)流反應(yīng)器結(jié)合應(yīng)該是一種是理想的氣液兩相反應(yīng)器構(gòu)型。目前針對(duì)均勻分布型內(nèi)環(huán)流反應(yīng)器的研究較多,而對(duì)噴射型內(nèi)環(huán)流反應(yīng)器的實(shí)驗(yàn)與模擬研究均較少。噴射型內(nèi)環(huán)流反應(yīng)器涉及高速射流、較寬的氣泡尺寸分布、大尺度的全塔液相循環(huán)等過程,流動(dòng)狀況復(fù)雜,對(duì)該類反應(yīng)器的流體力學(xué)狀況還不甚清楚。本文對(duì)噴射型內(nèi)環(huán)流反應(yīng)器的流體力學(xué)行為進(jìn)行了系統(tǒng)研究,在安裝有噴嘴和錐形底的內(nèi)置(?)100× 1400mm導(dǎo)流筒的(?)200×2500mm裝置內(nèi)開展冷模研究,測(cè)量了氣含率和液速的空間分布,考察了反應(yīng)器的多相流動(dòng)規(guī)律,并建立相關(guān)的CFD模型。實(shí)驗(yàn)結(jié)果表明,噴射型內(nèi)環(huán)流反應(yīng)器中噴嘴的射流會(huì)在底部產(chǎn)生較大尺寸的氣泡,氣泡在提升管中隨浮升而破碎,氣含率沿高度而增加,分布器影響區(qū)貫穿全塔;降液管中,由于液相對(duì)不同尺寸的氣泡攜帶能力不同,氣含率沿軸向遞增。噴嘴產(chǎn)生的大氣泡促進(jìn)了液相的循環(huán)流動(dòng),使循環(huán)速度成倍增大,有利于液相混合與固體懸浮。在實(shí)驗(yàn)的基礎(chǔ)上修正了曳力系數(shù)模型,并通過對(duì)比模擬結(jié)果和實(shí)驗(yàn)數(shù)據(jù),認(rèn)為大渦模擬要優(yōu)于可實(shí)現(xiàn)的k-ε模型。曳力修正因子的引入,使該模型能夠較好的模擬平均氣含率等宏觀量的變化,但由于單氣泡模型的缺陷,對(duì)于局部流動(dòng)特征的描述不盡如人意,僅在降液管內(nèi)得到了和實(shí)驗(yàn)吻合的氣含率和液速分布,在提升管內(nèi)的數(shù)值結(jié)果和實(shí)驗(yàn)差異較大,無法表現(xiàn)出噴射影響區(qū)貫穿全塔的特點(diǎn)。液相的進(jìn)料會(huì)顯著的促進(jìn)氣泡的破碎,使全塔的氣含率明顯增高。為了契合噴射型內(nèi)環(huán)流反應(yīng)器中氣泡分布較寬的特征,使用CFD-PBM耦合模型來對(duì)體系進(jìn)行模擬。該模型表現(xiàn)出了反應(yīng)器中由射流產(chǎn)生的大氣泡隨浮升而破碎,氣含率沿軸向高度增加,分布器影響區(qū)顯著延長的特征;大氣泡對(duì)液相循環(huán)流動(dòng)的促進(jìn)作用也得到了良好的展現(xiàn)。通過分析反應(yīng)器內(nèi)的速度矢量圖以及氣泡尺寸分布云圖,發(fā)現(xiàn)在液相流動(dòng)方向發(fā)生劇烈變化的區(qū)域,湍流耗散率較高,氣泡破碎更加顯著。實(shí)驗(yàn)和模擬研究表明,噴射型內(nèi)環(huán)流反應(yīng)器是一種能夠有效強(qiáng)化液相混合、氣液傳質(zhì)、固體懸浮的理想反應(yīng)器構(gòu)型。
[Abstract]:Internal annular flow reactor is widely used in heavy oil hydrogenation, biological fermentation, sewage treatment and other chemical processes. The inner ring flow reactor with uniform distributor is widely used in industry. The internal bubble size in the reactor is uniform, the gas holdup has little difference and the circulation speed is limited. The turbulence of strong fluid can effectively overcome the defect of insufficient circulation speed in traditional inner loop reactor. Small bubbles can promote gas-liquid mass transfer at the same time. The combination of jet distributor and inner ring flow reactor should be an ideal gas-liquid two phase reactor configuration. The experimental and Simulation Research of the internal annular flow reactor is less. The jet type inner ring flow reactor involves the high speed jet, the wider bubble size distribution, the large scale whole tower liquid cycle and so on, the flow condition is complex, and the hydrodynamics of the type reactor is not clear. The behavior was systematically studied. Cold model study was carried out in the (?) 100 x 1400mm guide tube (?) 200 x 2500mm installation with a nozzle and a conical bottom. The spatial distribution of gas holdup and liquid velocity was measured, the multiphase flow law of the reactor was investigated, and the related CFD model was established. The experimental results showed that the spray type inner ring flow reactor was sprayed. The jet of the nozzle produces a larger size bubble in the bottom, and the bubble is broken in the riser with the rise in the riser. The gas holdup increases along the height and the distributor affects the whole tower. In the drop pipe, the gas holdup increases along the axial direction because of the different carrying capacity of the liquid relative to different sizes. The large bubbles produced by the nozzle promote the circulation of liquid phase. On the basis of the experiment, the drag force coefficient model is modified. By comparing the simulation results and the experimental data, the large eddy simulation is considered to be better than the k- epsilon model. The introduction of the drag force correction factor makes the model better simulate the macroscopic gas holdup, such as the mean gas content. However, due to the defects of the single bubble model, the description of the local flow characteristics is not satisfactory. The gas holdup and the liquid velocity distribution that coincide with the experiment are only obtained in the downfall tube. The numerical results and the experimental differences in the riser can not show the characteristics of the penetration of the whole tower in the ejection area. The feed of the liquid phase will be significantly promoted. The gas holdup of the whole tower is obviously increased. In order to fit the wide distribution of the bubble in the jet type inner ring flow reactor, the CFD-PBM coupling model is used to simulate the system. The model shows that the large bubbles produced by the jet in the reactor are broken with the floating rise, the gas holdup increases along the axial height and the distributor affects the area. The effect of large bubbles on the liquid circulation flow is well demonstrated. Through the analysis of the velocity vector map and the bubble size distribution cloud in the reactor, it is found that the region where the liquid phase flow is changing sharply is higher and the bubble fragmentation is more significant. Experimental and simulation studies show that The jet type internal loop reactor is an ideal reactor configuration which can effectively enhance liquid phase mixing, gas-liquid mass transfer and solid suspension.

【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ021.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李孟;李向陽;王宏智;謝勇冰;曹宏斌;;鼓泡塔氣液兩相流不同曳力模型的數(shù)值模擬[J];過程工程學(xué)報(bào);2015年02期

2 Tingting Xu;Xuedong Jiang;Ning Yang;Jiahua Zhu;;CFD simulation of internal-loop airlift reactor using EMMS drag model[J];Particuology;2015年02期

3 姜來;;渣油沸騰床加氫技術(shù)現(xiàn)狀及操作難點(diǎn)[J];煉油技術(shù)與工程;2014年12期

4 莊黎偉;戴干策;;射流環(huán)流反應(yīng)器中顆粒懸浮的數(shù)值模擬[J];化學(xué)反應(yīng)工程與工藝;2014年05期

5 李紅星;;多相氣升式環(huán)流反應(yīng)器局部相含率和環(huán)流速度[J];化工進(jìn)展;2014年S1期

6 徐琰;董海峰;田肖;張香平;張鎖江;;鼓泡塔中離子液體-空氣兩相流的CFD-PBM耦合模擬[J];化工學(xué)報(bào);2011年10期

7 楊濤;方向晨;蔣立敬;葛海龍;劉建錕;賈麗;;STRONG沸騰床渣油加氫工藝研究[J];石油學(xué)報(bào)(石油加工);2010年S1期

8 沈雪松;沈春銀;李光;戴干策;;大孔徑高氣速單孔氣泡形成[J];化工學(xué)報(bào);2008年09期

9 魏淑賢,沈躍,黃延軍;計(jì)算流體力學(xué)的發(fā)展及應(yīng)用[J];河北理工學(xué)院學(xué)報(bào);2005年02期

10 劉夢(mèng)溪,盧春喜,儲(chǔ)凌,時(shí)銘顯;中心氣升式三相強(qiáng)化環(huán)流反應(yīng)器內(nèi)局部氣含率分布的實(shí)驗(yàn)研究[J];高�；瘜W(xué)工程學(xué)報(bào);2005年01期

相關(guān)博士學(xué)位論文 前3條

1 張濤;內(nèi)循環(huán)流化床反應(yīng)器流動(dòng)傳質(zhì)特性的計(jì)算流體力學(xué)模擬研究[D];華南理工大學(xué);2012年

2 張煜;湍動(dòng)鼓泡塔充分發(fā)展段的流體力學(xué)與內(nèi)構(gòu)件技術(shù)研究[D];浙江大學(xué);2011年

3 賈曉強(qiáng);氣液固三相生物反應(yīng)器流動(dòng)與降酚特性動(dòng)態(tài)行為研究[D];天津大學(xué);2009年

相關(guān)碩士學(xué)位論文 前6條

1 劉敏;加壓環(huán)流反應(yīng)器冷模實(shí)驗(yàn)研究[D];煤炭科學(xué)研究總院;2008年

2 李紅星;三相連續(xù)環(huán)流反應(yīng)器流動(dòng)特性研究[D];北京化工大學(xué);2007年

3 王麗雅;鼓泡塔中流動(dòng)與傳遞參數(shù)的檢測(cè)[D];浙江大學(xué);2006年

4 陳斌;鼓泡塔氧化反應(yīng)器內(nèi)構(gòu)件的研究[D];浙江大學(xué);2006年

5 薛勝偉;氣升式環(huán)流反應(yīng)器流動(dòng)與傳質(zhì)的研究[D];南京工業(yè)大學(xué);2005年

6 胡強(qiáng);噴嘴孔徑對(duì)鼓泡床內(nèi)氣泡分散和質(zhì)量傳遞的影響[D];四川大學(xué);2004年

，

本文編號(hào)：1856679