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  本文選題：旋流器 + 分股比　； 參考：《華北電力大學(xué)》2014年博士論文

【摘要】：石膏旋流器是火電廠石灰石-石膏濕法煙氣脫硫系統(tǒng)的重要設(shè)備,主要作用是對吸收塔中脫硫反應(yīng)的副產(chǎn)物石膏漿液進(jìn)行濃縮和分級,經(jīng)真空皮帶機(jī)脫水后生成的脫硫石膏廣泛應(yīng)用于水泥、建筑等領(lǐng)域。石膏旋流器在實(shí)際生產(chǎn)過程中存在底流夾細(xì)、分級效果不理想等問題,不僅干擾整個脫硫系統(tǒng)的正常運(yùn)行,還會影響生成石膏的品質(zhì)。因此正確認(rèn)識旋流器內(nèi)部的流動特性,設(shè)計(jì)高效節(jié)能的石膏旋流器具有重要意義。 本文闡述了旋流器內(nèi)流場的流動特性,對不同排口比的石膏旋流器進(jìn)行性能實(shí)驗(yàn),得到了分股比、底流漿液密度、底流排出方式、底流含固量等參數(shù)的變化規(guī)律,擬合得出分股比與排口比之間的關(guān)系式,并對排口比在0.3～1之間時,石膏旋流器的分級效率曲線進(jìn)行了比較,分析了底流夾細(xì)現(xiàn)象的產(chǎn)生原因。 利用Fluent軟件,選取RSM雷諾應(yīng)力模型與VOF流體體積模型,對固液旋流器中的重要現(xiàn)象——空氣柱進(jìn)行了數(shù)值模擬,包括其形成的整個過程、外觀形狀、三維速度場隨時間、空間的變化,分析了空氣柱對旋流器工作性能、能耗的影響,得到了空氣柱直徑隨入口速度、溢流管與底流管直徑以及介質(zhì)密度的變化規(guī)律。 基于空氣柱帶來的負(fù)面影響,設(shè)計(jì)倒錐形中心棒并選擇合理的安裝方式。對插入不同結(jié)構(gòu)尺寸中心棒的石膏旋流器進(jìn)行性能實(shí)驗(yàn),得到入口壓強(qiáng)、生產(chǎn)能力、底流與溢流漿液特性參數(shù)的變化情況,分析了中心棒對旋流器分級性能的影響,并以某4×600MW火電廠石膏旋流器的石膏生產(chǎn)情況為基礎(chǔ),通過計(jì)算得到了中心棒對整個實(shí)驗(yàn)系統(tǒng)的節(jié)能效果。 為提高石膏旋流器的分級性能,設(shè)計(jì)具有分離塊和隔板的新型旋流器入口結(jié)構(gòu)。采用DPM離散相模型,對不同粒徑石膏顆粒在新型入口中的運(yùn)動情況進(jìn)行數(shù)值模擬,分析了入口結(jié)構(gòu)與入口速度對顆粒運(yùn)動的影響,并對具有新型入口結(jié)構(gòu)的石膏旋流器進(jìn)行性能實(shí)驗(yàn),得到了入口結(jié)構(gòu)對指標(biāo)參數(shù)的影響,通過分級效率曲線反映出該入口結(jié)構(gòu)對中等粒度石膏顆粒的分級效率有明顯的提高。
[Abstract]:Gypsum cyclone is an important equipment of limestone gypsum wet flue gas desulfurization system in thermal power plant. The main function is to concentrate and classify gypsum slurry which is the by-product of desulfurization reaction in absorber. Desulphurized gypsum produced by dehydration of vacuum belt machine is widely used in cement, building and so on. In the actual production process of gypsum cyclone there are some problems such as fine bottom current clip and unsatisfactory classification effect which not only interfere with the normal operation of the whole desulfurization system but also affect the quality of gypsum formation. Therefore, it is of great significance to correctly understand the internal flow characteristics of hydrocyclone and design high efficiency and energy saving gypsum hydrocyclone. In this paper, the flow characteristics of the flow field in the hydrocyclone are described. The performance experiments of the gypsum cyclone with different discharge ratios are carried out, and the variation rules of the parameters such as the split ratio, the bottom flow slurry density, the bottom flow discharge mode and the bottom flow solid content are obtained. The relationship between split ratio and outlet ratio is obtained by fitting, and the classification efficiency curve of gypsum cyclone is compared when the discharge ratio is between 0.3 and 1, and the causes of the phenomenon of bottom flow clamping are analyzed. Using Fluent software, RSM Reynolds stress model and VOF fluid volume model are selected to simulate the air column, which is an important phenomenon in solid-liquid cyclone, including the whole process of its formation, appearance shape, and three-dimensional velocity field with time. The influence of air column on the performance and energy consumption of hydrocyclone is analyzed. The variation of air column diameter with inlet velocity, overflow tube and bottom flow tube diameter and medium density is obtained. Based on the negative effects of the air column, the inverted conical center rod is designed and the proper installation mode is chosen. The performance experiment of gypsum hydrocyclone with different structure size is carried out, and the change of inlet pressure, production capacity, bottom flow and overflow slurry characteristic parameters is obtained, and the influence of center rod on the classification performance of cyclone is analyzed. Based on the gypsum production of a 4 脳 600MW thermal power plant gypsum cyclone, the energy saving effect of the central rod on the whole experimental system is obtained by calculation. In order to improve the classification performance of gypsum hydrocyclone, a new type of inlet structure with separating block and partition board is designed. The DPM discrete phase model was used to simulate the movement of gypsum particles with different particle sizes in the new inlet. The effects of inlet structure and inlet velocity on the movement of the particles were analyzed. The influence of the inlet structure on the index parameters is obtained through the performance experiments of the gypsum cyclone with a new type of inlet structure. The classification efficiency of the inlet structure on the medium granularity gypsum particles is obviously improved by the classification efficiency curve.
【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：X773

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本文編號：1933459