本文關(guān)鍵詞：船舶尾氣凈化工藝與設(shè)備研究　出處：《北京化工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 船舶尾氣 海水脫硫 脫硫塔 脫硫效率 優(yōu)化設(shè)計(jì)

【摘要】：船舶柴油機(jī)排放尾氣中的硫氧化物SOx已成為當(dāng)前大氣污染的重要來(lái)源。國(guó)際公約MARPOL73/78則對(duì)SOx的排放提出了嚴(yán)格要求。為了有效應(yīng)對(duì)各國(guó)日益嚴(yán)格的船舶燃油硫含量和SO：的排放量限制,必須加強(qiáng)船舶硫化物排放控制研究。本文對(duì)比了多種技術(shù),認(rèn)為海水法脫硫劑(海水)就地取材,在船舶尾氣排放控制上具有優(yōu)越性。本文在分析SO2脫硫機(jī)理的基礎(chǔ)上,設(shè)計(jì)了一套以海水或淡水加堿為脫硫劑的雙模式煙氣脫硫系統(tǒng),可適應(yīng)不同地區(qū)排放要求；采用先曝氣再調(diào)節(jié)pH的工藝可減少設(shè)備數(shù)量及占地面積,投資成本�。徊捎梦那鹄锕茏鳛槊摿蛩跸雌�,降溫冷卻、初步洗滌SO2和除塵效果好,工藝流程簡(jiǎn)單,系統(tǒng)可靠性高。以脫硫塔作為整套海水脫硫裝置的核心設(shè)備,采用文丘里管式預(yù)處理裝置對(duì)入口煙氣做初步處理,螺旋形噴嘴為霧化噴嘴,通過噴淋塔內(nèi)氣液兩相流動(dòng)的CFD模擬,發(fā)現(xiàn)安裝兩層布?xì)獍逵欣诰鶆蛄鲌?chǎng)分布,降低流場(chǎng)整體速度；氣相在噴霧曳力作用下流向發(fā)生變化,噴嘴附近形成湍流與漩渦,由此證明合理布置孔板布?xì)獍搴驮黾訃娮鞌?shù)量可提高裝置脫硫效率。以柴油機(jī)燃燒尾氣模擬船舶尾氣,對(duì)加裝文丘里管式預(yù)處理裝置的海水脫硫系統(tǒng)的脫硫效果及影響因素進(jìn)行實(shí)驗(yàn)研究與分析,發(fā)現(xiàn)：雙層孔板布?xì)獍宓暮侠聿贾每善鸬絻?yōu)化流場(chǎng)分布的作用,脫硫效率約提高40%,在總流量為4 L·min-1時(shí),文丘里初洗區(qū)可清除約52%的SO2,起到降溫除塵、初步洗滌和縮短主塔高度作用；海水堿度、pH、溫度對(duì)脫硫效率影響較大,鹽度影響較小。海水堿度增大,pH值增大,脫硫效率明顯提高；煙氣中8O2含量與脫硫效率呈負(fù)相關(guān)關(guān)系。當(dāng)入塔8O2濃度增大到3040 mg·m-3時(shí),需要液氣比達(dá)到15 L·m-3才能取得脫硫效率97.04%以上,即達(dá)到燃油含硫限值小于0.1%；隨著液氣比的增加,脫硫效率會(huì)增大,當(dāng)液氣比增加到7.5 L·m-3以上后,脫硫效率增長(zhǎng)變得緩慢。適當(dāng)增大液氣比是提高脫硫效率的有效途徑,實(shí)驗(yàn)中液氣比在7.5 L·m-3以上能保證較好的脫硫效率。
[Abstract]:The sulfur oxide SOx in the exhaust gas of marine diesel engine has become an important source of air pollution at present, while the international convention MARPOL73/78 has put forward strict requirements for the emission of SOx. The increasingly stringent sulphur content of ship fuel and SOs:. Emission limits. It is necessary to strengthen the research on the discharge control of marine sulphide. This paper compares various technologies and thinks that the desulfurizer (seawater) is made locally. Based on the analysis of the mechanism of SO2 desulfurization, a two-mode flue gas desulfurization system using seawater or fresh water alkali as desulfurizer is designed. Can adapt to the emission requirements of different regions; The process of first aeration and then adjusting pH can reduce the number of equipments and occupy an area, and the investment cost is small. The Venturi tube is used as the primary scrubber for desulfurization tower, cooling and cooling, the primary washing SO2 and dust removal effect are good, the process flow is simple, the system reliability is high, and the desulfurization tower is taken as the core equipment of the whole seawater desulphurization unit. The inlet flue gas was treated with Venturi tube pretreating device. The spiral nozzle was used as atomizing nozzle, and the CFD simulation of gas-liquid two-phase flow in the spray tower was carried out. It is found that the installation of two-layer air distribution plate is beneficial to the uniform flow field distribution and the reduction of the overall velocity of the flow field. The flow direction of the gas phase changes under the action of spray drag, and turbulence and whirlpool are formed near the nozzle. It is proved that the efficiency of desulphurization can be improved by reasonably arranging the orifice plate and increasing the number of nozzles, and the tail gas of the ship is simulated by the combustion tail gas of the diesel engine. Experimental study and analysis of desulfurization effect and influencing factors of seawater desulfurization system with Venturi pipe pre-treatment system are carried out. It is found that the reasonable arrangement of double orifice plate can play an important role in optimizing the flow field distribution. When the total flow rate is 4 L 路min-1, the initial washing area of Venturi can remove about 52% of so _ 2, play the role of cooling and dust removal, preliminary washing and shortening the height of the main tower. The pH of seawater alkalinity and temperature have a great effect on desulfurization efficiency, but little effect on salinity. The content of 8O _ 2 in flue gas was negatively correlated with desulfurization efficiency, when the concentration of 8O _ 2 increased to 3040 mg 路m ~ (-3). The desulfurization efficiency is above 97.04% when the liquid-gas ratio is 15L 路m ~ (-3), that is, the limit value of sulfur content of fuel is less than 0.1L 路m ~ (-3). With the increase of liquid-gas ratio, the desulphurization efficiency will increase. When the liquid-gas ratio increases to more than 7.5 L 路m-3, the desulfurization efficiency increases slowly, and the proper increase of liquid-gas ratio is an effective way to improve the desulfurization efficiency. In the experiment, the ratio of liquid to gas above 7.5 L 路m ~ (-3) can guarantee a better desulphurization efficiency.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X736.3
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本文編號(hào)：1409245