【摘要】：隨著我國(guó)經(jīng)濟(jì)大跨步的發(fā)展,能源消耗和環(huán)境污染問(wèn)題也隨之加重。國(guó)家越來(lái)越重視工業(yè)生產(chǎn)的節(jié)能減排。我國(guó)能源結(jié)構(gòu)決定了燃煤電廠在電力行業(yè)有著重要的地位。如何最大限度的降低電廠排放煙塵所造成的污染一直以來(lái)都是極為重要的研究課題。其中提高除塵器的除塵效率就是緩解污染的有效手段之一,而流場(chǎng)分布的均勻程度是電廠除塵器除塵效率影響因素中的一項(xiàng)重要指標(biāo)。同時(shí),提高流場(chǎng)分布的均勻程度還有利于降低煙道的磨損,延長(zhǎng)煙道的使用壽命。燃煤火電廠煙道內(nèi)部構(gòu)件的設(shè)計(jì)好壞關(guān)系到煙道內(nèi)流場(chǎng)分布均勻程度。而彎頭作為煙道中較為常用也較為特殊的構(gòu)件已經(jīng)被國(guó)內(nèi)外學(xué)者從不同角度進(jìn)行了多方面研究。但縱觀專家學(xué)者的研究成果,鮮見(jiàn)對(duì)實(shí)際工程中帶有內(nèi)撐桿件的大型煙道進(jìn)行的模擬研究,而內(nèi)撐桿件對(duì)煙道煙氣的分布卻有著十分重要的作用,并不能完全忽略。因此,本文以工程中常用的規(guī)范標(biāo)準(zhǔn)煙道及CE方案煙道兩種煙道為原型,建立它們的彎管與直管段組合以及彎管與彎管組合模型,并借助計(jì)算流體動(dòng)力學(xué)軟件Fluent模擬除塵器模型前煙道的速度和壓力分布。隨后在原管道基礎(chǔ)上添加導(dǎo)流板進(jìn)行模擬,進(jìn)而優(yōu)化原管道內(nèi)部結(jié)構(gòu)的設(shè)計(jì)。研究結(jié)果表明:內(nèi)撐結(jié)構(gòu)是造成煙道局部阻力損失的主要原因,阻力損失所占份額均為總阻力損失的50%左右;彎管與直管組合形式的煙道中,規(guī)范標(biāo)準(zhǔn)內(nèi)撐結(jié)構(gòu)優(yōu)于CE方案的內(nèi)撐結(jié)構(gòu),而對(duì)于彎管與彎管組合來(lái)說(shuō)兩種內(nèi)撐方案區(qū)別不明顯;常規(guī)導(dǎo)流板的布置可以提高煙道流場(chǎng)分布的均勻性,但是更需要一種既能導(dǎo)流又能起到支撐作用的構(gòu)件來(lái)代替;在所得基礎(chǔ)研究的結(jié)論基礎(chǔ)上,設(shè)計(jì)了以“變外部急轉(zhuǎn)為內(nèi)部緩轉(zhuǎn)”為設(shè)計(jì)理念的新型煙道,使得出口煙氣走向更加均勻。彎管與直管組合的新型煙道壓力損失與原模型相比降低約40%。彎管與彎管組合的新型煙道也在不同方面獲得了優(yōu)于原方案的結(jié)果。所得結(jié)論可應(yīng)用于工程選型,為管道內(nèi)的支撐件及導(dǎo)流部件的布置提供較為可靠的理論依據(jù)及方法指導(dǎo)。
[Abstract]:With the rapid development of China's economy, energy consumption and environmental pollution are becoming more and more serious. The country is paying more and more attention to the energy saving and emission reduction of industrial production. China's energy structure determines that coal-fired power plants play an important role in the power industry. How to minimize the pollution caused by smoke and dust emission from power plants has always been a very important research topic. Improving the dust removal efficiency of the dust collector is one of the effective measures to alleviate the pollution, and the uniformity of the flow field distribution is an important index of the factors affecting the dust removal efficiency of the dust collector in the power plant. At the same time, increasing the uniformity of the flow field distribution is beneficial to reduce the wear and tear of the flue and prolong the service life of the flue. The design of internal components of flue in coal-fired power plant is related to the uniformity of flow field in flue. As a common and special component in flue, elbow has been studied from different angles by scholars at home and abroad. However, throughout the research results of experts and scholars, few simulation studies have been carried out on large-scale flue gas with internal strut members in practical engineering, but the internal strut members play a very important role in the distribution of flue gas, and cannot be completely ignored. Therefore, taking the standard flue and CE scheme as prototypes, the combination of bend and straight pipe and the combination model of bends and bends are established in this paper. The velocity and pressure distribution of the flue in front of the precipitator model are simulated with the aid of computational fluid dynamics software Fluent. Then a diversion plate is added to the foundation of the original pipeline to simulate and optimize the design of the internal structure of the original pipe. The results show that the internal brace structure is the main cause of the local resistance loss of flue, and the share of resistance loss is about 50% of the total resistance loss. In the combination of bent pipe and straight pipe, the standard internal brace structure is better than the inner brace structure of CE scheme, but the difference between the two brace schemes is not obvious for the combination of bent pipe and straight pipe. The layout of conventional diversion plate can improve the uniformity of the flow field in the flue, but it needs a kind of component which can not only guide the flow but also play a supporting role. On the basis of the conclusion of the basic research, a new type of flue gas is designed, which is based on the design idea of "changing the external urgency to the internal slow rotation", which makes the outlet flue gas more uniform. Compared with the original model, the pressure loss of the new flue in the combination of bends and straight pipes is reduced by about 40%. The results of the combination of bends and bends are better than those of the original scheme in different aspects. The conclusions obtained can be applied to engineering selection and provide reliable theoretical basis and method guidance for the layout of the support and diversion components in the pipeline.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU834.6

【引證文獻(xiàn)】

相關(guān)期刊論文 前2條

1 章華熔;林翔;葉興聯(lián);吳桂平;;流場(chǎng)優(yōu)化消除煙道振動(dòng)研究[J];電力科技與環(huán)保;2018年02期

2 陳煉非;胡南;;風(fēng)道入口段的數(shù)值模擬及優(yōu)化設(shè)計(jì)[J];沈陽(yáng)工程學(xué)院學(xué)報(bào)(自然科學(xué)版);2017年02期

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本文編號(hào)：2469778