發(fā)布時間：2018-06-08 05:49

  本文選題：低溫省煤器 + 鍋爐尾部煙道��； 參考：《東華大學》2014年碩士論文

【摘要】：隨著政府節(jié)能改革的深化,電站鍋爐尾部煙道的余熱利用的重要性日益增長。低溫省煤器的引入,極大地提升了鍋爐的換熱效率,但是隨之而來的也有一些問題需要研究者得以重視。因此,合理設置低溫省煤器,根據(jù)其前后煙道的偏流現(xiàn)象,提出改進方案,改善鍋爐尾部煙道低溫省煤器前后部分的流場均勻性,可以減少磨損,防止換熱設備因磨損而爆管,對于電廠的安全經(jīng)濟運行有極大的意義。 本課題基于華東電力設計院的實際工程項目,在全面了解低溫省煤器等余熱利用設備的基礎上,按照設計手冊對低溫省煤器和空氣預熱器進行設計計算,得到合理設計參數(shù),再采用此參數(shù),使用計算流體力學的方法,建立起省煤器前后煙道和空氣預熱器后、除塵器前煙道的數(shù)值模型,其中：省煤器前后煙道關注轉彎煙道,除塵器前煙道關注分岔煙道,兩個數(shù)值模型通過對速度場的研究,對不同煙道結構、不同參數(shù)流體、不同均流布置下的煙道流場進行數(shù)值模擬計算,對比分析得到較優(yōu)煙道優(yōu)化方案,改善煙道內流場不均勻性,從而降低了換熱設備爆管的可能性,提高熱力發(fā)電廠機組經(jīng)濟性。 通過課題計算得出針對實際工程項目低溫省煤器和空氣預熱器的合理設計參數(shù),按照設計參數(shù)的模型分析得出原設計方案存在磨損嚴重的可能性,通過對省煤器前煙道設置兩層導流板：第一層三塊導流板,第二層四塊導流板,實現(xiàn)轉彎煙道和變截面擴展煙道的流場均勻性改善；通過調整除塵器前煙道管道形狀、煙道轉彎角度和入口流速度,實現(xiàn)長距離煙道的流場均勻性改善,保證進入除塵器的煙氣流動分配均勻。通過方案內各因素的調整,能很好實現(xiàn)低溫省煤器前后煙道整體流場均勻性的改善,保證鍋爐尾部煙道內各余熱利用設備的高效運行。 同時,本文所做工作也為鍋爐尾部煙道流場的優(yōu)化設計和電廠機組的經(jīng)濟安全運行提供了理論支持和數(shù)值參考。
[Abstract]:With the deepening of the government's energy-saving reform, the importance of waste heat utilization in the tail flue of power plant boiler is increasing day by day. The introduction of low temperature economizer has greatly improved the efficiency of boiler heat transfer, but there are also some problems that need to be paid attention to by researchers. Therefore, the reasonable setting of low temperature economizer, according to the deviation phenomenon of the flue before and after, the improvement scheme is put forward to improve the uniformity of flow field in the front and back parts of the low temperature economizer of boiler tail flue, which can reduce the wear and avoid the tube explosion of the heat exchanger because of wear and tear. It is of great significance to the safe and economical operation of power plant. Based on the actual project of East China Electric Power Design Institute, this subject is based on a comprehensive understanding of the low temperature economizer and other waste heat utilization equipment. According to the design manual, the low temperature economizer and the air preheater are designed and calculated, and the reasonable design parameters are obtained. After adopting this parameter and using the method of computational fluid dynamics, the flue and air preheater before and after the economizer are established, The numerical model of flue in front of dust collector, in which: before and after economizer pay attention to turn flue, before dust collector pay attention to bifurcation flue, two numerical models through the study of velocity field, to different flue structure, different parameter fluid, The flow field of flue under different flow sharing arrangement is simulated by numerical simulation, and the optimal flue optimization scheme is obtained by contrast analysis, which can improve the non-uniformity of flow field in flue, thus reducing the possibility of tube burst in heat exchanger. The reasonable design parameters of cryogenic economizer and air preheater for practical engineering project are obtained by calculating the economic efficiency of units in thermal power plant. According to the model analysis of design parameters, the possibility of serious wear in the original design scheme is obtained. The flow field uniformity of the turn flue and the expanded flue with variable cross section is improved by installing two layers of flow guide plate in the front flue of the economizer: the first layer three guide plates and the second layer four flow guide plates; by adjusting the shape of the flue pipe before the dust collector, the flow field uniformity of the flue duct is improved by adjusting the flow field of the flue duct before the dust collector. The flow field uniformity of long distance flue can be improved by turning angle of flue and inlet velocity, and the flow distribution of flue gas entering the dust collector will be uniform. By adjusting all the factors in the scheme, the uniformity of the flow field of the flue before and after the low temperature economizer can be well improved, and the efficient operation of the remaining heat utilization equipment in the flue at the tail of the boiler can be ensured, at the same time, The work in this paper also provides theoretical support and numerical reference for the optimization design of boiler tail flue flow field and the economic and safe operation of power plant units.
【學位授予單位】：東華大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM621.2

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本文編號：1994800