【摘要】：近年來,隨著水輪機組單機容量及轉輪直徑的不斷增大,電站已經(jīng)不再片面追求高效率,而是把運行穩(wěn)定性放在首位。圓筒閥作為一種新型的進水閥,它是安裝在水輪機的固定導葉和活動導葉之間,它能夠起到止水閥的作用,可以阻止水流通過活動導葉,對于泥沙含量高的電站,在機組停機時,能夠很好的保護導水機構,避免由于間隙空化和泥沙磨損造成的導葉漏水量過大。此外,當機組事故甩負荷時,如果調(diào)速器失靈,機組發(fā)生飛逸,圓筒閥是可以動水關閉的,避免了水輪發(fā)電機組長時間的處于飛逸狀態(tài),從而保護了機組的安全。因此對混流式水輪機圓筒閥進行研究十分必要。論文以某個投標項目為例,應用商業(yè)CFD軟件CFX14.0對水輪機全流道的三維流動進行了數(shù)值計算,通過CFD數(shù)值模擬獲得了在不同水頭和流速下圓筒閥所體現(xiàn)的水力特性,并由此得到特定水頭和流速范圍下圓筒閥的最優(yōu)幾何外形;對機械液壓控制裝置的研究開發(fā);對圓筒閥本身和水輪機頂蓋、座環(huán)等部件的相關結構進行了研究,結合圓筒閥筒體的導向結構、筒體的剛強度及屈曲分析、筒體固有振動頻率等方面確定筒體的結構尺寸。已經(jīng)能夠運用CFD分析計算圓筒閥在關閉過程中流道內(nèi)速度場、壓力場的變化情況、圓筒閥閥體內(nèi)外表面的壓力特性以及周圍流場變化、圓筒閥在關閉過程中閥體的受力情況進行分析計算;最后通過模擬試驗,試驗結果表明在模擬試驗中,圓筒閥操作機構功能正常,圓筒閥同步性好,動作過程無卡阻;能夠進行真機的圓筒閥結構及水輪機的相關部件的設計,以及對圓筒閥機械液壓控制裝置的成果已經(jīng)能夠用于真機水輪機的設計。
[Abstract]:In recent years, with the increasing of single turbine capacity and runner diameter, the power station has no longer one-sided pursuit of high efficiency, but put the operation stability in the first place. As a new type of inlet valve, the cylinder valve is installed between the fixed guide vane and the movable guide vane of the turbine. It can act as a water stop valve and can prevent the flow of water from passing through the moving guide vane. When the unit is shut down, the water guide mechanism can be protected well, and the leakage of guide vane caused by clearance cavitation and sediment wear can be avoided. In addition, if the governor is out of order, the cylinder valve can be closed with water if the governor is out of order, thus avoiding the long time runaway state of the turbine generator set, thus protecting the safety of the unit. So it is necessary to study the cylinder valve of Francis turbine. Taking a bidding project as an example, a commercial CFD software CFX14.0 is used to numerically calculate the three-dimensional flow of a hydraulic turbine. The hydraulic characteristics of the cylinder valve under different water head and velocity are obtained by CFD numerical simulation. From this, the optimal geometry of cylinder valve under specific water head and velocity range, the research and development of mechanical hydraulic control device, the relative structure of cylinder valve itself and the top cover and seat ring of hydraulic turbine are studied. Combined with the guide structure of the cylinder valve, the rigid strength and buckling analysis of the cylinder, and the natural vibration frequency of the cylinder, the structural size of the cylinder is determined. It has been possible to use CFD analysis to calculate the variation of velocity field and pressure field in the runner during the closure of the cylinder valve, the pressure characteristics of the inner and outer surface of the cylinder valve body and the changes of the flow field around the valve body. Finally, through the simulation test, the test results show that in the simulation test, the function of the operating mechanism of the cylinder valve is normal, the cylinder valve has good synchronicity, and the movement process is unobstructed. The design of cylinder valve structure and related parts of hydraulic turbine, as well as the results of mechanical hydraulic control device of cylinder valve can be used in the design of real turbine.
【學位授予單位】：西安理工大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TK733.1

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相關期刊論文 前10條

1 李穎;李國曉;劉子祺;孫見波;雷恒;;混流式水輪機全流道內(nèi)部流場CFD數(shù)值模擬研究[J];電網(wǎng)與清潔能源;2016年04期

2 李文鋒;馮建軍;羅興，

本文編號：2143822