本文選題：SCR催化劑 + 反應效率�。� 參考：《浙江大學》2014年碩士論文

【摘要】：國內(nèi)燃煤電站實際應用SCR(選擇性催化還原)煙氣脫硝技術(shù)過程中,經(jīng)常出現(xiàn)中、低負荷下SCR反應器入口煙溫低于SCR催化劑的最佳反應溫度窗口,嚴重時甚至低于正常反應溫度等問題,導致SCR反應器運行效率明顯偏低,嚴重影響鍋爐的脫硝效率、NOx排放濃度和氨逃逸率,同時氨逃逸率增加還會引起空預器的堵灰問題。因此,需要在不影響鍋爐整體運行下,有效提高SCR反應效率,維持SCR催化劑的較高活性,保證原SCR反應器系統(tǒng)高效穩(wěn)定運行的同時,解決空預器堵灰隱患。 本文以某重點地區(qū)燃煤電站300MW機組作為研究對象,從工程應用角度出發(fā),尋求開發(fā)提高SCR反應效率的煙溫優(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)化選擇了高溫煙氣旁路方案作為煙溫控制方案,其旁路煙氣份額最大為20%；同時,創(chuàng)新性地提出了SCR省煤器,用于解決高溫煙氣旁路帶來的排煙溫度升高的不利影響,并通過熱力計算確定了SCR省煤器面積(原省煤器面積的40%)。 對高溫煙氣旁路與SCR省煤器聯(lián)合布置方案進行了詳細的模擬計算,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℃。 高溫煙氣旁路與SCR省煤器聯(lián)合布置煙溫協(xié)調(diào)優(yōu)化方案基本實現(xiàn)了全運行工況下SCR入口煙溫在340℃以上的催化劑高效運行需求,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,鍋爐負荷越高排煙溫度下降幅度越大,假設全年平均負荷為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：1948841