發(fā)布時(shí)間：2018-05-29 00:46

  本文選題：SCR催化劑 + 反應(yīng)效率　； 參考：《浙江大學(xué)》2014年碩士論文

【摘要】：國(guó)內(nèi)燃煤電站實(shí)際應(yīng)用SCR(選擇性催化還原)煙氣脫硝技術(shù)過(guò)程中,經(jīng)常出現(xiàn)中、低負(fù)荷下SCR反應(yīng)器入口煙溫低于SCR催化劑的最佳反應(yīng)溫度窗口,嚴(yán)重時(shí)甚至低于正常反應(yīng)溫度等問(wèn)題,導(dǎo)致SCR反應(yīng)器運(yùn)行效率明顯偏低,嚴(yán)重影響鍋爐的脫硝效率、NOx排放濃度和氨逃逸率,同時(shí)氨逃逸率增加還會(huì)引起空預(yù)器的堵灰問(wèn)題。因此,需要在不影響鍋爐整體運(yùn)行下,有效提高SCR反應(yīng)效率,維持SCR催化劑的較高活性,保證原SCR反應(yīng)器系統(tǒng)高效穩(wěn)定運(yùn)行的同時(shí),解決空預(yù)器堵灰隱患。 本文以某重點(diǎn)地區(qū)燃煤電站300MW機(jī)組作為研究對(duì)象,從工程應(yīng)用角度出發(fā),尋求開(kāi)發(fā)提高SCR反應(yīng)效率的煙溫優(yōu)化調(diào)整技術(shù)。 本文首先提出了四種不同煙溫調(diào)整方案,并最終優(yōu)化選擇了高溫?zé)煔馀月贩桨缸鳛闊煖乜刂品桨?其旁路煙氣份額最大為20%；同時(shí),創(chuàng)新性地提出了SCR省煤器,用于解決高溫?zé)煔馀月穾?lái)的排煙溫度升高的不利影響,并通過(guò)熱力計(jì)算確定了SCR省煤器面積(原省煤器面積的40%)。 對(duì)高溫?zé)煔馀月放cSCR省煤器聯(lián)合布置方案進(jìn)行了詳細(xì)的模擬計(jì)算,結(jié)果表明,在最低煙溫工況下,SCR入口煙溫可調(diào)節(jié)達(dá)到接近340℃,排煙溫度略有增加；在最高煙溫工況下,SCR入口煙溫不需調(diào)節(jié),排煙溫度可降低6.1℃。 高溫?zé)煔馀月放cSCR省煤器聯(lián)合布置煙溫協(xié)調(diào)優(yōu)化方案基本實(shí)現(xiàn)了全運(yùn)行工況下SCR入口煙溫在340℃以上的催化劑高效運(yùn)行需求,排煙溫度在更小、更優(yōu)化的范圍內(nèi)變化�？傮w上排煙溫度呈下降趨勢(shì),鍋爐負(fù)荷越高排煙溫度下降幅度越大,假設(shè)全年平均負(fù)荷為75%,則近似平均排煙溫度下降5.2℃,發(fā)電煤耗降低接近1g/kWh。
[Abstract]:In the practical application of SCR (selective Catalytic reduction) flue gas denitrification in coal-fired power plants in China, the inlet smoke temperature of SCR reactor under low load is often lower than the optimal reaction temperature window of SCR catalyst. The operation efficiency of SCR reactor is obviously low when it is serious or even lower than normal reaction temperature, which seriously affects the NOx emission concentration and ammonia escape rate of boiler. At the same time, the increase of ammonia escape rate will also cause the ash plugging problem of air preheater. Therefore, it is necessary to effectively improve the efficiency of SCR reaction, maintain the higher activity of SCR catalyst, and ensure the efficient and stable operation of the original SCR reactor system without affecting the overall operation of the boiler, and at the same time solve the hidden danger of ash plugging in the air preheater. In this paper, the 300MW unit of a coal-fired power station in a key area is taken as the research object. From the point of view of engineering application, this paper seeks to develop the optimization adjustment technology of gas temperature to improve the efficiency of SCR reaction. In this paper, four different kinds of smoke temperature adjustment schemes are put forward, and the high temperature flue gas bypass scheme is selected as the smoke temperature control scheme, and the maximum bypass flue gas share is 20. At the same time, the SCR economizer is innovatively proposed. It is used to solve the adverse effect of high temperature flue gas bypass on the rise of exhaust gas temperature, and the area of SCR economizer (40% of the original economizer area) is determined by thermodynamic calculation. The detailed simulation calculation of the arrangement scheme of high temperature flue gas bypass and SCR economizer is carried out. The results show that under the lowest smoke temperature condition, the inlet smoke temperature can be adjusted to nearly 340 鈩，

本文編號(hào)：1948841