本文選題：水泵水輪機　切入點：數(shù)值模擬　出處：《哈爾濱工業(yè)大學》2014年碩士論文　論文類型：學位論文

【摘要】：近年來為滿足用電需求新建了一批大型火電、核電機組。大容量機組的投產(chǎn)使用對電網(wǎng)的穩(wěn)定性以及快速響應特性提出了更高的要求，必須建立與之配套的調(diào)節(jié)系統(tǒng)，抽水蓄能電站憑借其良好的調(diào)頻調(diào)峰能力成為電網(wǎng)調(diào)節(jié)的首選，水泵水輪機的穩(wěn)定性問題也因此成為關注的焦點。在諸多影響穩(wěn)定運行的因素中，無葉區(qū)強烈的動靜干涉及復雜的壓力脈動是導致運行不穩(wěn)定的主要原因之一，嚴重時會引發(fā)機組振動、噪聲甚至葉片裂紋，因此有必要對無葉區(qū)壓力特性及脈動機理進行深入的研究，為水泵水輪機的設計及穩(wěn)定運行提供參考。 為研究無葉區(qū)的壓力特性，本文采用CFD技術對國內(nèi)某抽水蓄能電站水輪機工況下模型和真機同一單位轉(zhuǎn)速，不同導葉開度以及模型導葉擺動過程進行了數(shù)值模擬，對無葉區(qū)壓力脈動進行了詳細的分析，本文主要內(nèi)容如下： （1）根據(jù)真機實際運行工況點，選取模型6個不同開度進行數(shù)值計算，獲得了外特性及壓力脈動幅值隨開度變化的曲線，并與試驗數(shù)據(jù)進行了對比。隨后給出了無葉區(qū)壓力脈動頻率的理論預測并通過數(shù)值模擬進行驗證，詳細分析了最優(yōu)工況無葉區(qū)壓力脈動特性及上下游傳播規(guī)律，并對模型無葉區(qū)壓力脈動隨導葉開度變化的規(guī)律進行了簡要分析。 （2）選取真機50%負荷，最優(yōu)開度以及滿負荷等3個工況進行數(shù)值計算，分別與模型對應的相似工況進行了詳細的對比分析，研究模型與真機無葉區(qū)壓力脈動頻率成分及幅值大小的異同，探究模型與真機之間的換算關系。 （3）對模型采用動網(wǎng)格方法計算，以18°作為起始開度，模擬導葉左右擺動1°過程中無葉區(qū)壓力脈動特性，，對導葉不同轉(zhuǎn)動狀態(tài)下無葉區(qū)壓力脈動幅值大小，時域以及頻域特性進行了研究，最后對比分析了導葉整個擺動過程與導葉定開度過程無葉區(qū)壓力脈動的異同。 研究結(jié)果表明，無葉區(qū)壓力脈動主要頻率是轉(zhuǎn)輪葉片通過頻率及其諧波頻率，此外還存在來自于轉(zhuǎn)輪和尾水管的頻率成分。無葉區(qū)壓力脈動更容易向上游傳播，但不同頻率分量幅值衰減不一。不同導葉開度對無葉區(qū)壓力脈動特性有顯著影響。相似工況下真機與模型頻率成分基本一致，但幅值大小差異較大且沒有明顯的換算關系。導葉擺動過程無葉區(qū)9倍頻以下頻率成分豐富，相對定開度峰峰值明顯增大。
[Abstract]:In recent years, in order to meet the demand for electricity, a new batch of large thermal power and nuclear power units and large capacity units have been built up and put forward higher requirements for the stability of the power network and the characteristics of rapid response. It is necessary to establish a matching regulation system. Pumped-storage power station has become the first choice of power network regulation by virtue of its good capacity of frequency modulation and peak-shaving, and the stability of pump turbine has become the focus of attention. Among the factors that affect the stable operation of pumped-storage power station, One of the main causes of unstable operation is the strong dynamic and static interference and complex pressure fluctuation in the leafless area, which can lead to vibration, noise and even blade cracks in severe cases. Therefore, it is necessary to deeply study the pressure characteristics and pulsation mechanism in the leafless region to provide a reference for the design and stable operation of the pump turbine. In order to study the pressure characteristics in the vaneless region, a numerical simulation was carried out by using CFD technique to simulate the model and the actual unit rotating speed, the different guide vane opening degree and the model guide vane swing process under the same unit speed and the same unit speed of the turbine in a domestic pumped storage power station. The pressure fluctuation in the leafless region is analyzed in detail. The main contents of this paper are as follows:. 1) according to the actual operating conditions of the real machine, six different openings of the model are selected for numerical calculation, and the curves of the external characteristics and the amplitude of pressure pulsation with the opening degree are obtained. The theoretical prediction of pressure pulsation frequency in vaneless region is given and verified by numerical simulation. The characteristics of pressure fluctuation and the propagation law of upstream and downstream in the optimal condition are analyzed in detail. The variation of pressure pulsation with the opening of the guide vane is analyzed briefly. 2) selecting the 50% load, optimal opening and full load of the real machine to carry out numerical calculation, and comparing and analyzing in detail with the similar working conditions corresponding to the model. The differences and similarities of pressure pulsation frequency components and amplitudes between the model and the real machine are studied, and the conversion relationship between the model and the real machine is discussed. The dynamic grid method is used to calculate the model. With 18 擄as the initial opening, the characteristics of the pressure pulsation in the vaneless region during the 1 擄swing of the guide vane are simulated, and the amplitude of the pressure pulsation in the vaneless region under different rotating conditions of the guide vane is studied. The characteristics in time domain and frequency domain are studied. Finally, the differences and similarities of the pressure pulsation in the vaneless region between the whole swing process of the guide vane and the opening process of the guide vane are compared and analyzed. The results show that the main frequency of pressure pulsation in the leafless region is the frequency and harmonic frequency of the runner blade, in addition, there are frequency components from the runner and the draft tube, and the pressure pulsation in the leafless zone is more easily propagated upstream. However, the amplitude attenuation of different frequency components is different. The pressure pulsation characteristics in the vaneless region are significantly affected by the different guide vane openings. The frequency components of the real machine and the model are basically the same under similar operating conditions. However, the amplitude varies greatly and there is no obvious conversion relationship. The frequency components below 9 times frequency in the leafless region of the guide vane swing process are rich, and the peak value of the relative opening degree increases obviously.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TK730

【參考文獻】

相關期刊論文 前8條

1 陳金霞;李國偉;劉勝柱;呂桂萍;;葉道渦產(chǎn)生機理及對水輪機穩(wěn)定性的影響[J];大電機技術;2007年03期

2 孫躍昆;劉樹紅;劉錦濤;吳玉林;左志剛;;水泵水輪機開機過程壓力脈動的試驗研究[J];工程熱物理學報;2012年08期

3 劉樹紅;邵杰;吳墑鋒;吳玉林;;軸流轉(zhuǎn)槳式水輪機壓力脈動數(shù)值預測[J];中國科學(E輯:技術科學);2009年04期

4 龐立軍;呂桂萍;鐘蘇;劉晶石;;水輪機固定導葉的渦街模擬與振動分析[J];機械工程學報;2011年22期

5 錢忠東;鄭彪;楊建東;吳玉林;;水輪機補氣條件下壓力脈動的數(shù)值分析[J];水力發(fā)電學報;2008年04期

6 張宇寧;劉樹紅;吳玉林;;混流式水輪機壓力脈動精細模擬和分析[J];水力發(fā)電學報;2009年01期

7 陳杰;;從俄羅斯薩揚電站事故探討加強水電站運行管理[J];四川水力發(fā)電;2010年06期

8 程路;白建華;;新時期中國抽水蓄能電站發(fā)展定位及前景展望[J];中國電力;2013年11期

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