水泵水轮机在非设计工况下流动不稳定特性的研究

发布时间：2023-05-07 23:50

　　能源无疑是当今各个国家经济和社会发展的关键因素。电力作为众多能源形式之一,是发展中国家在各领域争取自给自足的关键点。基于农村地区的经济优势,电力供应机构最近提出一种使用泵作透平(PAT)作为远程离网电气化微型水电站(MHP)方案。泵作透平相当于在相反的旋转方向进行工作的以用于发电的目的普通液压泵。尽管在农村小型水电站中使用泵作透平带来了许多好处,但目前也发现了许多问题,这主要是因为它们流量无法控制,同时缺少有关涡轮机运行特性的数据有关,从而使它们易受流动不稳定的影响而且工作区间较小。众所周知,泵作透平只能在0.8 BEP到1.0 BEP的工作区间内运行,一旦脱离这个非常小的工作区间,机器内部流道会产生严重的漩涡,导致相应的局部高压脉动和结构振动。这些现象最终可能影响整个机组的工作效率甚至导致结构损坏,如叶片破损。此外,小型水电站大部分安装在流动不稳定的山区小河流上,这使得它们处于不可预测的流动条件下,而且PAT的流入条件还与季节性降水有关。因此,满足条件的可用流量大部分时间段内处于空载状态下,这导致机器长期的运行不稳定。尽管上述问题的科学机理尚不清楚,但不同的研究者已经尝试了不同的PA...

【文章页数】：209 页

【学位级别】：博士

【文章目录】：
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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