共查询到19条相似文献,搜索用时 437 毫秒
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汽轮发电机组转子轴系扭振主动控制的模拟研究 总被引:3,自引:3,他引:3
该文分析了汽轮发电机组转子轴系的扭振问题,提出了采用主动控制消除扭振危害的技术措施。文中建立了机组轴系扭振主动控制的离散化系统模型,利用最小能量法分别导出了轴系在局部控制和全局控制下的最优控制规律,进行了转子轴系扭振主动控制过程的计算机模拟,从理论上得到了在不同控制规律作用下汽轮发电机组轴系扭振总能量的衰减特性,提出了具有一定的工程意义的扭振主动控制方案,并对未来汽轮发电机组轴系实现扭振主动控制的 相似文献
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本文采用初参数法对轴系振动进行分析和计算,阐述了轴系振动的基本方法,给出了汽轮机轴系振动简化的力学模型及该系统的数学模型,给出了计算轴系临界转速的步骤和算法,并结合实际问题进行求解。 相似文献
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汽轮发电机组轴系扭振主动控制模拟实验研究 总被引:5,自引:0,他引:5
在理论分析的基础上建立了国产200MW汽轮发电机转子轴系扭振主动控制模拟试验台,并在该试验台上进行了阻尼减振和主动控制减振等多项实验研究,结果表明主动控制可以有铲地抑制汽轮发电机组轴系的扭振。 相似文献
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把现代控制理论与机械振动理论相结合 ,建立了汽轮发电机组轴系扭振主动控制的状态空间模型 ,以减少轴系总扭振能和控制源能量为优化目标 ,提出了汽轮发电机组轴系扭振的二次型全局最优控制算法 ,并编制了适用于连续和离散两类系统设计的仿真通用计算程序 ,并对 1台 2 0 0 MW汽轮发电机组轴系进行扭振主动控制模拟计算分析 相似文献
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It is imperative to include three‐dimensional tip flow corrections when using low‐order rotor models that rely on the flow independence principle to compute the blade forces. These corrections aim to account for the effect of pressure equalization at the tips and the accompanying spanwise pressure gradients on the outboard sections, by reducing the computed axial and tangential forces as the blade tips are approached. While Glauert‐type corrections are conventionally employed for actuator disc‐type computations, alternative corrections are required for actuator line computations as they use a finite blade representation. We present actuator line computations of the Model Rotor Experiments in Controlled Conditions (MEXICO) rotor to investigate tip corrections. Using the tip correction factor proposed by Shen et al. (Wind Energy 2005; 8:457–475), the actuator line computations show an improvement in accuracy over similar computations undertaken without a tip correction factor included. Further improvement to the blade loading is achieved by recalibrating the tip correction factor using data extracted from blade resolved computations of the model rotor experiments in controlled conditions rotor. From the rotor resolved computations, the tip loss (reduction in the blade loading on the outboard sections) is found to be more aggressive in the tangential direction than the axial direction. To account for this, we recalibrate the tip correction factor separately in the axial and tangential directions to develop new directionally dependent tip corrections. The resulting actuator line computations show a further improvement in accuracy of the tangential blade loading, resulting in better prediction of the rotor power. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Extracting lift and drag polars from blade‐resolved computational fluid dynamics for use in actuator line modelling of horizontal axis turbines 下载免费PDF全文
Low order rotor models such as the actuator line method are desirable as an efficient method of computing the large range of operating and environmental conditions, required to design wind and tidal rotors and arrays. However, the integrated thrust and torque predictions for each rotor are dominated by the blade loading on the outboard sections, where three‐dimensional (3D) effects become increasingly significant, and the accuracy of the reduced order methods remains uncertain. To investigate the accuracy of the spanwise blade loading on an individual rotor, actuator line and blade boundary layer resolved computations of the Model Rotor Experiments in Controlled Conditions (MEXICO) rotor are presented. The high fidelity blade‐resolved simulations give good agreement with measured pressure coefficient and particle image velocimetry data. Alternative lift and drag polars are extracted from the 3D simulated flow fields as a function of radial position. These are then used as replacement inputs for the actuator line method. Significant improvement in the accuracy of the actuator line predictions is found when using these 3D extracted polars, compared with using simulated two‐dimensional lift and drag polars with empirical correction applied to the spanwise loading distribution. Additionally, the 3D flow field data is used to derive different axial and tangential spanwise loading corrections for use with the two‐dimensional blade polars. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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汽轮发电机组轴系扭转振动对机械参数的敏感性分析 总被引:3,自引:0,他引:3
针对某300MW汽轮发电机组模型,分析了扭振固有频率和振型对汽轮发电机组轴系转动惯量和刚度的敏感性。计算结果表明:无论是轴系整体转动惯量或刚度、还是局部转动惯量或刚度的变化,都会对扭振特性产生明显的影响;局部转动惯量或刚度的改变对特定阶的扭振的影响虽然不及整体转动惯量和刚度变化的影响大,但也十分显著;对特定振型贡献较大的轴段对此阶轴系扭振影响较大,在振型图上表示为此阶振型在这一轴段处的斜率较大;在实际中可以通过改变轴系局部结构,使某阶扭振固有频率避开特定的值,从而达到调频的目的,而在对汽轮发电机组轴系扭振研究的建模过程中,要精确确定扭振特性敏感性较高的那些部位的机械参数。图4表2参8 相似文献
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为解决汽轮机组低压缸轴承振动大的问题,对低压转子振动响应特性进行了研究。基于转子动力学理论建立了转子-轴承支撑系统有限元分析模型,考虑支撑刚度对转子系统振动的影响,计算了不同支撑刚度下转子轴承振动、轴振和绝对轴振响应特性。研究表明:不同支撑刚度下转子不平衡振动响应差异较大,柔性支撑下,轴承振动较大,轴振较小;转子绝对轴振能够较为真实的反映实际振动情况,3 000 r/min工作转速时,柔性支撑下轴承振动对转子不平衡力变化较为敏感;现场可通过精细动平衡降低轴承振动。 相似文献