本文選題：涌波　切入點(diǎn)：瞬變流　出處：《武漢大學(xué)》2017年碩士論文

【摘要】：河床式水電站一般修建在河道中下游,有水頭低、引用流量大的特點(diǎn)。由于河床式水電站的水頭低,當(dāng)機(jī)組引用流量發(fā)生變化時(shí),涌波占機(jī)組水頭比重大,會(huì)對(duì)電站機(jī)組的安全穩(wěn)定運(yùn)行產(chǎn)生不良影響。對(duì)于布置于多江汊上的水利樞紐,多江之間的涌波往復(fù)現(xiàn)象明顯,引起機(jī)組出力波動(dòng),引航道水位波動(dòng)等問(wèn)題。這直接關(guān)系到電網(wǎng)、船閘和庫(kù)區(qū)安全的綜合社會(huì)效益。所以分析涌波影響因素及傳播規(guī)律,評(píng)價(jià)涌波對(duì)機(jī)組運(yùn)行和航運(yùn)的不良影響,探求涌波的有效控制措施具有研究意義。本文應(yīng)用Delft3D軟件對(duì)河床式水電站中涌波的影響因素、傳播規(guī)律及其控制措施進(jìn)行了較為系統(tǒng)的研究。主要內(nèi)容如下:1.闡述涌波問(wèn)題研究背景和意義,對(duì)明渠非恒定流、水電站涌波、涌波控制措施研究現(xiàn)狀進(jìn)行了概述,提出本文研究方法和內(nèi)容。2.闡述淺水動(dòng)力學(xué)基本理論,包括平面二維流動(dòng)基本方程,淺水方程離散方法。介紹Delft3D軟件的控制方程和時(shí)間差分方法。通過(guò)典型算例驗(yàn)證,模擬駝峰流和水電站尾水明渠非恒定流,與理論、文獻(xiàn)結(jié)果對(duì)比,驗(yàn)證了 Delft3D模擬涌波的準(zhǔn)確性,可見(jiàn)該軟件可用于研究河道涌波問(wèn)題。3.利用簡(jiǎn)單矩形河道模型研究機(jī)組流量變化值、導(dǎo)葉關(guān)閉時(shí)間、河床糙率、河道寬度及河道初始水深等因素對(duì)涌波的影響規(guī)律,以判別涌波的主要影響因素,作為涌波控制措施設(shè)計(jì)的依據(jù)。4.利用一島兩江河道模型分析機(jī)組不同運(yùn)行方式與涌波的相互影響,選擇合理的機(jī)組運(yùn)行方案。模擬對(duì)比機(jī)組"甩負(fù)荷時(shí)與鄰近閘門(mén)聯(lián)合操作"和"導(dǎo)葉分段關(guān)閉"兩種涌波控制措施的效果,選擇效果較好的措施應(yīng)用于實(shí)際工程模擬。5.結(jié)合某水利樞紐工程,研究多江汊上水電站涌波性態(tài),分析涌波對(duì)河床式水電站運(yùn)行機(jī)組和航運(yùn)的影響。以最不利工況為例,分析"甩負(fù)荷時(shí)與鄰近閘門(mén)聯(lián)合操作"這一涌波控制措施的效果。本文運(yùn)用CFD軟件Delft3D,對(duì)河床式水電站過(guò)渡過(guò)程涌波現(xiàn)象進(jìn)行了較系統(tǒng)的研究,得到了涌波影響因素及傳播規(guī)律,涌波對(duì)庫(kù)區(qū)流態(tài)、通航條件的影響。本文的研究成果可為河床式水電站設(shè)計(jì)提供參考。
[Abstract]:River bed type hydropower stations are generally built in the middle and lower reaches of the river, with the characteristics of low water head and large quoted flow. Because of the low water head of river bed type hydropower stations, the surge wave accounts for a large proportion of the unit water head when the unit suction flow changes. It will have an adverse effect on the safe and stable operation of the power station units. For the water conservancy projects arranged on the Duojiang branch, the reciprocating phenomenon between the multi-rivers is obvious, which causes the generating force fluctuation of the generating units. The fluctuation of water level in approach channel is directly related to the comprehensive social benefit of the safety of power grid, lock and reservoir area. Therefore, the influence factors and propagation rules of surge wave are analyzed, and the adverse effects of surge wave on unit operation and shipping are evaluated. It is of great significance to explore the effective control measures of surge. In this paper, Delft3D software is applied to the influencing factors of surge in river bed hydropower stations. The propagation law and its control measures are systematically studied. The main contents are as follows: 1. The background and significance of the research on the problem of surge are expounded, and the current situation of the research on the unsteady flow of open channel, the surge of hydropower station and the control measures of surge is summarized. The basic theory of shallow water dynamics, including the basic equations of planar two-dimensional flow and the discrete method of shallow water equations, is presented. The control equation and time difference method of Delft3D software are introduced. The simulation of hump flow and unsteady flow in the open tail channel of hydropower station is compared with the theoretical and literature results, and the accuracy of Delft3D simulation of surge is verified. It can be seen that the software can be used to study the problems of channel surge. 3. Using simple rectangular channel model to study the influence law of unit discharge value, lead blade closing time, river bed roughness, channel width and initial water depth, etc. In order to distinguish the main influencing factors of surge, as the basis of the design of surge control measures, the paper analyzes the interaction between unit operation mode and surge by using the model of one island and two rivers. Select reasonable operation plan of the unit, simulate and compare the effect of two kinds of surge control measures: "combined operation with adjacent gate" and "guide vane segment closure" when the unit is under load rejection, The measures with good effect are applied to the practical engineering simulation. 5. Combined with a water conservancy project, the surge behavior of the hydropower station at the Duojiang branch is studied, and the influence of the surge on the operating unit and shipping of the riverbed hydropower station is analyzed. Taking the most unfavorable working conditions as an example, This paper analyzes the effect of "combined operation of load rejection and adjacent gate" as a surge control measure. In this paper, CFD software Delft3D is used to study the phenomenon of surge in the transient process of river bed hydropower station, and the influencing factors and propagation law of surge are obtained. The influence of surge on the flow state and navigation conditions of reservoir area. The research results in this paper can be used as a reference for the design of river bed hydropower stations.
【學(xué)位授予單位】：武漢大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TV737;TV139.2

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本文編號(hào)：1672393