本文關(guān)鍵詞： 大功率 工業(yè)透平 末級 葉頂間隙 平衡凝結(jié)模型 泄漏量 流固耦合　出處：《大連理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：為保證軸流汽輪機的動靜元件在運行中不發(fā)生碰磨,設(shè)計時會在動葉葉頂和汽缸內(nèi)壁之間留有一定的間隙。因此,動葉葉頂存在間隙泄漏流動,泄漏引起的泄漏渦與主流的摻混作用所造成的損失已經(jīng)成為提高汽輪機的氣動性能和效率必須要解決的關(guān)鍵問題。目前,對10萬千瓦等級的大功率工業(yè)汽輪機而言,尚沒有準(zhǔn)確計算其葉頂泄漏損失的模型,這已經(jīng)影響到該等級工業(yè)汽輪機的效率核算和性能評估；并因此降低了我國同類型產(chǎn)品在國際市場的競爭力,成為更高等級工業(yè)汽輪機設(shè)計與開發(fā)的瓶頸。為了準(zhǔn)確評價該等級工業(yè)汽輪機末幾級的級性能,并探究末幾級葉頂泄漏的特點,本文依據(jù)杭州汽輪動力集團有限公司提供的某大功率工業(yè)汽輪機末三級葉片數(shù)據(jù)和設(shè)計參數(shù),建立了末三級聯(lián)算的計算模型,首先選用平衡兩相濕蒸汽模型,對三級主流道內(nèi)和間隙內(nèi)部的流動進行了數(shù)值模擬研究,詳細(xì)分析了間隙泄漏流動的形成和發(fā)展,充分闡述了間隙泄漏流動和主流之間的相互作用。其次對不同進口流量工況進行了數(shù)值計算,對比了不同工況下汽輪機末三級的性能,并分析了不同進口流量對末三級流動以及對葉頂間隙泄漏量的影響。然后在設(shè)計工況下,改變末三級動葉葉頂間隙值,探究不同葉項間隙值與汽輪機級性能之間的相互關(guān)系,分析了不同間隙下,泄漏流動和主流之間的關(guān)系。分析了動葉葉頂間隙變化和軸向間隙變化對末三級性能參數(shù)的影響,提供了一種末三級性能參數(shù)隨末三級動葉葉頂間隙變化的關(guān)系式擬合方法,并擬合了多變效率以及末三級動葉葉頂泄漏量與末三級動葉葉頂間隙的關(guān)系式,之后對結(jié)果進行誤差分析,證明關(guān)系式具有較高的可信度。最后分別采用單純考慮葉片轉(zhuǎn)動,單向流固耦合和雙向流固耦合方法對動葉進行徑向變形計算,并在計算中考慮因動葉徑向變形導(dǎo)致葉頂間隙減小帶來的影響,對比分析了采用不同的固體變形計算方法時,葉片在高速轉(zhuǎn)動的情況下的徑向伸長量,并分析了葉頂徑向伸長量和末三級的性能參數(shù)的關(guān)系。本文研究的結(jié)論可為今后該等級的工業(yè)汽輪機進一步的市場開拓提供一定的理論支撐,同時也為更高等級的工業(yè)透平的研發(fā)奠定理論基礎(chǔ)。
[Abstract]:In order to ensure that the static and static components of the axial flow turbine do not collide in operation, there will be a certain gap between the top of the moving blade and the inner wall of the cylinder in the design. The loss caused by leakage vortex mixing with mainstream has become a key problem to be solved to improve the aerodynamic performance and efficiency of steam turbine. There is no accurate model for calculating the leakage loss at the top of the blade, which has affected the efficiency accounting and performance evaluation of the industrial steam turbine of this class, and thus reduced the competitiveness of the same type of products in the international market. It has become the bottleneck in the design and development of higher grade industrial steam turbine. In order to evaluate the performance of the last stage of the industrial steam turbine accurately, and to explore the characteristics of the leakage of the top blade of the last stage of the industrial steam turbine, Based on the data and design parameters of the final three stage blade of a high power industrial steam turbine provided by Hangzhou Turbine Power Group Co., Ltd., the calculation model of the final three stage combined calculation is established in this paper. First, the equilibrium two phase wet steam model is selected. Numerical simulation of the flow in the three-stage main channel and in the clearance is carried out, and the formation and development of the leakage flow in the gap are analyzed in detail. The interaction between the clearance leakage flow and the mainstream is fully expounded. Secondly, the numerical calculation of different inlet flow conditions is carried out, and the performance of the last stage of the turbine under different working conditions is compared. The influence of different inlet flow rate on the flow at the end of the third stage and on the leakage of the tip clearance of the blade is analyzed. Then, under the design condition, the relationship between the clearance value of the blade and the performance of the steam turbine stage is studied by changing the clearance value of the tip of the last three stage moving blade. The relationship between leakage flow and mainstream under different clearance is analyzed, and the influence of the change of tip clearance and axial clearance of moving blade on the final three stage performance parameters is analyzed. In this paper, a fitting method of the relation between the performance parameters of the last three stage and the top clearance of the last three stage moving blade is presented, and the relationship between the variable efficiency and the leakage rate between the top of the last three stage moving blade and the top clearance of the last three stage moving blade is fitted. Finally, the radial deformation of the moving blade is calculated by considering the blade rotation, unidirectional fluid-solid coupling and bidirectional fluid-solid coupling, respectively. In the calculation, the influence of blade tip clearance decrease caused by radial deformation of moving blade is considered, and the radial elongation of blade under the condition of high speed rotation is compared and analyzed with different calculation methods of solid deformation. The relationship between the radial elongation of the blade top and the performance parameters of the last stage is analyzed. The conclusion of this paper can provide some theoretical support for the further market development of the industrial steam turbine of this grade in the future. At the same time, it also lays a theoretical foundation for the research and development of higher grade industrial turbine.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TK269.4

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本文編號：1545869