能源無疑是當今各個國家經(jīng)濟和社會發(fā)展的關(guān)鍵因素。電力作為眾多能源形式之一,是發(fā)展中國家在各領(lǐng)域爭取自給自足的關(guān)鍵點。基于農(nóng)村地區(qū)的經(jīng)濟優(yōu)勢,電力供應(yīng)機構(gòu)最近提出一種使用泵作透平(PAT)作為遠程離網(wǎng)電氣化微型水電站(MHP)方案。泵作透平相當于在相反的旋轉(zhuǎn)方向進行工作的以用于發(fā)電的目的普通液壓泵。盡管在農(nóng)村小型水電站中使用泵作透平帶來了許多好處,但目前也發(fā)現(xiàn)了許多問題,這主要是因為它們流量無法控制,同時缺少有關(guān)渦輪機運行特性的數(shù)據(jù)有關(guān),從而使它們易受流動不穩(wěn)定的影響而且工作區(qū)間較小。眾所周知,泵作透平只能在0.8 BEP到1.0 BEP的工作區(qū)間內(nèi)運行,一旦脫離這個非常小的工作區(qū)間,機器內(nèi)部流道會產(chǎn)生嚴重的漩渦,導(dǎo)致相應(yīng)的局部高壓脈動和結(jié)構(gòu)振動。這些現(xiàn)象最終可能影響整個機組的工作效率甚至導(dǎo)致結(jié)構(gòu)損壞,如葉片破損。此外,小型水電站大部分安裝在流動不穩(wěn)定的山區(qū)小河流上,這使得它們處于不可預(yù)測的流動條件下,而且PAT的流入條件還與季節(jié)性降水有關(guān)。因此,滿足條件的可用流量大部分時間段內(nèi)處于空載狀態(tài)下,這導(dǎo)致機器長期的運行不穩(wěn)定。盡管上述問題的科學(xué)機理尚不清楚,但不同的研究者已經(jīng)嘗試了不同的PA...

【文章頁數(shù)】：209 頁

【學(xué)位級別】：博士

【文章目錄】：
摘要
Abstract
Nomenclature
Chapter1 Introduction
    1.1 Hydropower
        1.1.1 Small hydropower
        1.1.2 Pumped Storage Hydropower
        1.1.3 Reversible pump turbine flow stability aspects
        1.1.4 Reversible pump turbine flow instability-related hydraulic phenomena
    1.2 Research Objectives
    1.3 Thesis organization
Chapter2 Numerical simulation research methodology
    2.1 Introduction
    2.2 Computational fluid dynamics
        2.2.1 Pre-processor
        2.2.2 Solver
        2.2.3 Post-processor
    2.3 Fluid flow governing equations
        2.3.1 Navier-Stokes Equations
        2.3.2 Reynolds-averaged Navier-Stokes equations
    2.4 Fluid flow turbulence modelling
        2.4.1 The k-εturbulence model
        2.4.2 The k-ωTurbulence model
        2.4.3 The shear stress transport(SST)model
    2.5 Boundary layer Modelling
    2.6 The solver
        2.6.1 Boundary conditions
    2.7 Summary
Chapter3 Pump as turbine(PAT)flow instability aspects under off-design conditions
    3.1 Introduction
    3.2 Geometric model and numerical method
        3.2.1 Geometric model
        3.2.2.Numerical Method
    3.3 Results and analysis
        3.3.1 Volute
        3.3.2 Impeller
        3.3.3 Outlet pipe
    3.4 Summary
Chapter4 Reversible Pump Turbine flow instability aspects under off-design conditions:A focus on guide vane opening Influence
    4.1 Introduction
    4.2 Research object and Methods
        4.2.1 Pump Turbine Model
        4.2.2 Numerical Simulation Scheme and Validation
    4.3 Results and Discussion
        4.3.1 Flow field characteristics and evolution
        4.3.2 Pressure Pulsation analysis
    4.4 Summary
Chapter5 Reversible pump turbine flow instability aspects under off-design conditions:A focus on runner blade number influence
    5.1 Introduction
    5.2 Research Object and Method
        5.2.1 RPT geometric model
        5.2.2 Numerical Simulation scheme and Validation
    5.3 Results and discussion
        5.3.1 Runner inter-blade flow field analysis
        5.3.2 Runner inlet zones pressure pulsation analysis
        5.3.3 Runner upstream zones flow and pressure pulsation analysis
    5.4 Summary
Conclusions
    Future works
References
Papers published during the Ph.D.education
Acknowledgement
Curriculum Vitae



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