圆筒阀在混流式水轮机中的应用与研究
发布时间：2018-07-25 12:28
【摘要】：近年来,随着水轮机组单机容量及转轮直径的不断增大,电站已经不再片面追求高效率,而是把运行稳定性放在首位。圆筒阀作为一种新型的进水阀,它是安装在水轮机的固定导叶和活动导叶之间,它能够起到止水阀的作用,可以阻止水流通过活动导叶,对于泥沙含量高的电站,在机组停机时,能够很好的保护导水机构,避免由于间隙空化和泥沙磨损造成的导叶漏水量过大。此外,当机组事故甩负荷时,如果调速器失灵,机组发生飞逸,圆筒阀是可以动水关闭的,避免了水轮发电机组长时间的处于飞逸状态,从而保护了机组的安全。因此对混流式水轮机圆筒阀进行研究十分必要。论文以某个投标项目为例,应用商业CFD软件CFX14.0对水轮机全流道的三维流动进行了数值计算,通过CFD数值模拟获得了在不同水头和流速下圆筒阀所体现的水力特性,并由此得到特定水头和流速范围下圆筒阀的最优几何外形;对机械液压控制装置的研究开发;对圆筒阀本身和水轮机顶盖、座环等部件的相关结构进行了研究,结合圆筒阀筒体的导向结构、筒体的刚强度及屈曲分析、筒体固有振动频率等方面确定筒体的结构尺寸。已经能够运用CFD分析计算圆筒阀在关闭过程中流道内速度场、压力场的变化情况、圆筒阀阀体内外表面的压力特性以及周围流场变化、圆筒阀在关闭过程中阀体的受力情况进行分析计算;最后通过模拟试验,试验结果表明在模拟试验中,圆筒阀操作机构功能正常,圆筒阀同步性好,动作过程无卡阻;能够进行真机的圆筒阀结构及水轮机的相关部件的设计,以及对圆筒阀机械液压控制装置的成果已经能够用于真机水轮机的设计。
[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.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TK733.1
[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.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TK733.1
【参考文献】
相关期刊论文 前10条
1 李颖;李国晓;刘子祺;孙见波;雷恒;;混流式水轮机全流道内部流场CFD数值模拟研究[J];电网与清洁能源;2016年04期
2 李文锋;冯建军;罗兴，
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