本文選題：飽和濕煙氣　切入點(diǎn)：冷凝換熱　出處：《山東大學(xué)》2017年碩士論文

【摘要】：燃煤鍋爐尾部煙氣中含有大量余熱及SO_2、SO_3、微細(xì)顆粒等污染物,濕法煙氣脫硫的大規(guī)模應(yīng)用,雖然有效的控制了 Sb排放,但脫硫后飽和濕煙氣仍然含有大量潛熱,同時(shí)攜帶有少量的微細(xì)顆粒、SO_2等污染物,現(xiàn)有的濕式靜電等末端控制技術(shù)難以兼顧余熱回收與污染物的協(xié)同脫除。本文針對(duì)上述問題,提出了煙氣深度降溫余熱回收協(xié)同污染物脫除技術(shù),在理論分析基礎(chǔ)上,針對(duì)不同位置煙氣的特點(diǎn),分別設(shè)計(jì)并搭建了濕煙氣冷凝換熱協(xié)同污染物脫除中試試驗(yàn)系統(tǒng)以及SO_3冷凝機(jī)理實(shí)驗(yàn)系統(tǒng),研究了煙氣深度降溫余熱回收效率以及冷凝換熱過(guò)程中微細(xì)顆粒物、SO_2、SO_3的脫除規(guī)律,為促進(jìn)煙氣余熱回收與污染物協(xié)同脫除技術(shù)提供基礎(chǔ)數(shù)據(jù)。首先,本文在理論分析的基礎(chǔ)上,建立了脫硫后飽和濕煙氣冷凝換熱協(xié)同污染物脫除試驗(yàn)系統(tǒng),通過(guò)冷凝實(shí)現(xiàn)煙氣深度溫降,來(lái)研究冷凝器對(duì)濕法脫硫后濕煙氣的換熱性能,以及不同運(yùn)行參數(shù)下微細(xì)顆粒物、SO_2脫除效率,研究發(fā)現(xiàn):冷凝器對(duì)脫硫后飽和濕煙氣的換熱性能良好,凝結(jié)水回收率在90%以上。濕煙氣降溫冷凝對(duì)微細(xì)顆粒的分級(jí)脫除效率整體呈"U"型分布,脫除效率隨冷卻水流量與濕煙氣溫降的增加而增加,隨濕煙氣中微細(xì)顆粒物濃度、煙氣流量的增加而降低。實(shí)驗(yàn)中在最佳工況下,濕煙氣溫度從50℃降到20℃,微細(xì)顆粒物脫除效率可達(dá)40%左右;煙氣深度冷凝對(duì)SO_2也有一定脫除效果,煙氣流量不變,其脫除效率隨冷卻水流量與入口 SO_2濃度的增加均先增加后減少,其脫除量隨入口 SO_2濃度的增加而增加,在入口濃度200mg/Nm3左右時(shí)迅速上升,此后增長(zhǎng)趨于穩(wěn)定。試驗(yàn)中在最佳工況下SO_2脫除效率在15%～20%之間,通過(guò)增加鈣基吸收劑可有效提高脫硫效率。其次,建立了SO_3冷凝機(jī)理實(shí)驗(yàn)系統(tǒng),研究了不同條件下SO_3冷凝析出規(guī)律,研究發(fā)現(xiàn):煙溫低于10C℃時(shí),SO_3凝結(jié)收集效率隨著冷凝溫度的增加而增加;煙溫到100～～20℃左右時(shí),可收集幾乎全部的SO_3;隨著冷凝溫度繼續(xù)增加到煙氣酸露點(diǎn)以上時(shí),SO_3收集率迅速降低。SO_3及水蒸氣濃度的增加都會(huì)導(dǎo)致SO_3冷凝收集效率降低,且SO_3濃度對(duì)收集效率產(chǎn)生的影響較大。相同條件下,SO_3收集率:直型冷凝管蛇型冷凝管帶過(guò)濾棉的蛇型冷凝管,而單純?cè)黾永淠艿拈L(zhǎng)度,對(duì)收集效率的增加影響不大。
[Abstract]:The flue gas of coal-fired boiler tail contains a large amount of waste heat and pollutants such as so _ 2 / so _ 3 and so _ 2 / so _ 3, etc. Although the large-scale application of wet flue gas desulfurization (WFGD) can effectively control the discharge of SB, the saturated wet flue gas still contains a large amount of latent heat after desulphurization.At the same time, a small amount of fine particles such as so _ 2 are carried. The existing wet electrostatic equal-end control technology is difficult to take into account the waste heat recovery and the coordinated removal of pollutants.In order to solve the above problems, this paper puts forward the technology of removing pollutants from waste heat recovery by deep cooling of flue gas. On the basis of theoretical analysis, according to the characteristics of flue gas in different locations,A pilot test system for the co-removal of pollutants from wet flue gas condensation heat transfer and an experimental system for the mechanism of SO_3 condensation were designed and built, respectively. The recovery efficiency of waste heat from deep cooling of flue gas and the removal law of fine particulate matter so _ 2SO _ 3 in the process of condensation and heat transfer were studied.It provides the basic data for promoting the technology of flue gas waste heat recovery and pollutant removal.Firstly, on the basis of theoretical analysis, this paper establishes the experimental system of condensing heat transfer of saturated wet flue gas after desulphurization, and realizes the deep temperature drop of flue gas through condensation to study the heat transfer performance of the condenser for wet flue gas after wet desulphurization.The results show that the condenser has good heat transfer performance for saturated wet flue gas after desulphurization, and the condensate recovery rate is over 90%.The fractionation efficiency of wet flue gas cooling and condensing is "U". The removal efficiency increases with the increase of cooling water flow and the temperature drop of wet smoke, and decreases with the increase of the concentration of fine particles in the wet flue gas and the increase of flue gas flow rate.Under the optimum conditions, the removal efficiency of fine particles can reach about 40% when the wet flue gas temperature is reduced from 50 鈩，

本文編號(hào)：1727128