共查询到19条相似文献,搜索用时 140 毫秒
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大型汽轮发电机组轴系不对中振动的研究 总被引:10,自引:0,他引:10
轴系不对中可分为联轴器不对中、轴瓦中心标高偏差以及转子与静子不同心三种类型,分析讨论各种不对中情况的力学机理及振动故障特征,给出联轴器不对中的晃度控制参考标准,并介绍各种不对中故障的工程实际案例。轴振晃度是联轴器对中状态的直接反映,可利用轴振晃度数据诊断联轴器不对中。在安装和检修过程中应严格进行轴系找中、在运行过程中应避免对机组轴系形成冲击负荷,才能保证大型汽轮发电机组的安全、稳定、经济运行。图7表8参8 相似文献
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转子系统联轴器不对中是旋转机械频发的故障之一,尤其体现在多跨多轴系转子系统。模拟双跨-三支撑转子系统建立有限元模型,利用坎贝尔图得出一阶临界转速;搭建双跨-三支撑转子系统试验装置,试验测得在联轴器偏角不对中故障影响下,转子系统振动的频谱图、轴心轨迹和时域波形,分析转子系统振动特性。试验结果表明:随着偏角不对中量的不断增大,转子系统在通过临界转速时,1倍频振幅的增长倍率呈现递增趋势;转子在升速过程中,在偏角不对中故障影响下,2倍频伴随升速过程,且轴心轨迹会呈现"8"字形;在偏角不对中故障影响下,3倍频在通过临界转速时,其增长倍率最大;对于三支撑系统,与联轴器不同侧的转子系统受到联轴器偏角不对中振动的影响很小。 相似文献
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转子系统联轴器不对中是旋转机械频发的故障之一,尤其体现在多跨多轴系转子系统。模拟双跨-三支撑转子系统的有限元模型,求得转子研究范围内的一阶、二阶临界转速;建立了双跨-三支撑转子系统试验装置,测得联轴器偏角不对中量变化时转子系统振动的频谱图与轴心轨迹,分析转子系统振动特性。通过试验结果分析,得出结论:随着偏角不对中量的不断增大,转子系统一阶临界呈现递增的趋势,二阶临界转速影响不大;转子升速过程中,发生偏角不对中时,2倍频明显增加,且轴心轨迹会呈现"8"字形或"香蕉"形;随不对中量的增加,2倍频伴随整个升速过程,当转速升到较高速度时,其幅值进入无规律状态。 相似文献
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大坝电站300MW机组不对中振动故障的诊断处理 总被引:2,自引:1,他引:2
通过进行发电机有功负荷、转子电流(无功)、发电机转子冷却水温试验以及瞬态试验,诊断出励磁机振动故障的根本原因为发电机-励磁机联轴器不对中。采取现场重新铰孔找中的方法,成功消除了励磁机的振动故障。 相似文献
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引入一种可在线调节转子轴位置的支承结构--电磁辅助支承,它通过控制电磁执行器线圈中的电流可在线调整转子轴在空间的位置,使转子系统轴系间的不对中消除.将不对中引起的附加振动视为一干扰量,针对其采用自寻最优控制算法和具有自学习功能的前馈控制算法,使得转子在不停车的情况下自动实现不对中的识别和控制.最后在单盘对称转子轴承系统上进行了试验验证和比较,试验结果证明两种控制方法对轴系间的不对中都具有较好的校正能力.其中不对中自寻最优控制器不需要建立关于不对中系统精确的数学模型表达式,对位移传感器的要求不高,但搜索时间较长;不对中前馈自学习控制器也无需建立精确的数学模型,搜索时间较短,但对位移传感器的要求相对较高. 相似文献
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为了解多故障耦合机制下的水电机组转子运动特性,利用能量守恒的拉格朗日方程建立简化的转子动力学仿真模型,基于正交试验原理,以振动峰值为评估目标,分析了质量偏心、转子平行不对中、转子夹角不对中、转速等因素对机组转子动力特性的影响。结果表明,多故障耦合机制下,质量偏心影响权重最大,转子平行不对中和夹角不对中的权重关系与转速有关,即低速时夹角不对中影响较大,反之则相反;转速较高时,转子易发生碰摩现象。 相似文献
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This paper presents a detailed analysis of the rotor–tower interaction and the effects of the rotor's tilt angle and yaw misalignment on a large horizontal axis wind turbine. A high‐fidelity aeroelastic model is employed, coupling computational fluid dynamics (CFD) and structural mechanics (CSM). The wind velocity stratification induced by the atmospheric boundary layer (ABL) is modeled. On the CSM side, the complex composite structure of each blade is accurately modeled using shell elements. The rotor–tower interaction is analyzed by comparing results of a rotor‐only simulation and a full‐machine simulation, observing a sudden drop in loads, deformations, and power production of each blade, when passing in front of the tower. Subsequently, a tilt angle is introduced on the rotor, and its effect on blade displacements, loads, and performance is studied, representing a novelty with respect to the available literature. The tilt angle leads to a different contribution of gravity to the blade deformations, sensibly affecting the stresses in the composite material. Lastly, a yaw misalignment is introduced with respect to the incoming wind, and the resulting changes in the blade solicitations are analyzed. In particular, a reduction of the blade axial displacement amplitude during each revolution is observed. 相似文献
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Research on optimal confguration of hybrid energy storage capacity for wind-solar generation system 下载免费PDF全文
LI Ruimin ZHANG Xinjing XU Yujie SUN Wenwen ZHOU Xuezhi GUO Cong CHEN Haisheng 《储能科学与技术》2019,8(3):512-522
储能系统可以有效解决微电网中分布式可再生能源特别是风光互补发电的间歇性、波动性以及“源”与“荷”错位的问题。不同储能技术在响应时间、容量规模、技术成熟度及成本等方面各有特点,两种或多种储能技术耦合将可以更有效地满足用电系统的技术性和经济性的要求。针对电力用户对分布式可再生能源的利用情况,本文提出一种由压缩空气储能、锂电池和超级电容器组成的混合储能系统,建立了三种储能的数学模型,针对其不同的特性,提出了基于二次移动平均滤波的储能系统功率分配方法和基于连续性运行的容量优化配置方法。基于某个实际的用户负荷进行了案例分析,得到了混合储能系统的功率和容量配置结果,并分析了其运行特性。研究表明,在分布式可再生能源微电网中,多种储能技术耦合既能充分发挥每种储能的优势,又可以通过相互配合弥补各自的劣势,这对于可再生能源的充分利用和满足用电负荷的严苛需求具有重要的作用和意义,在分布式能源利用领域具有较好的工程应用前景。 相似文献
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Consideration is given to the validity of single axis tracking systems for solar concentrators of low to medium concentration ratios having moderate acceptance angles. If the misalignment between the sun and reflector normals is within the acceptance angle perfect tracking can be assumed. Rotation about a fixed polar axis gives a constant misalignment equal ot the sun's declination angle on that day. Rotation about a declination axis gives perfect alignment at noon, but increasing misalignment towards each end of the day varying with the time from the equinoxes. Data is also given for monthly adjustment of the declination axis. All the results are independant of latitude. 相似文献
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《International Journal of Pressure Vessels and Piping》1987,30(4):241-251
Submerged structures subjected to external pressure frequently have fabricated spherical end-closures. Misalignment can occur between plates, which could have a catastrophic effect on the collapse strength of the end-closure. The collapse process could be helped or hindered by other shape imperfections which may interact with the misalignment.The current investigation centres on predicting reductions on the collapse strength of torispherical dome end-closures due to plate misalignment and shape imperfections using non-linear finite element analyses. Comparisons are made with empirical data. The interaction of coincident and closely spaced shape imperfections with the misaligned plates was also studied. 相似文献
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Vertical wind shear is one of the dominating causes of load variations on the blades of a horizontal axis wind turbine. To alleviate the varying loads, wind turbine control systems have been augmented with sensors and actuators for individual pitch control. However, the loads caused by a vertical wind shear can also be affected through yaw misalignment. Recent studies of yaw control have been focused on improving the yaw alignment to increase the power capture at below rated wind speeds. In this study, the potential of alleviating blade load variations induced by the wind shear through yaw misalignment is assessed. The study is performed through simulations of a reference turbine. The study shows that optimal yaw misalignment angles for minimizing the blade load variations can be identified for both deterministic and turbulent inflows. It is shown that the optimal yaw misalignment angles can be applied without power loss for wind speeds above rated wind speed. In deterministic inflow, it is shown that the range of the steady‐state blade load variations can be reduced by up to 70%. For turbulent inflows, it is shown that the potential blade fatigue load reductions depend on the turbulence level. In inflows with high levels of turbulence, the observed blade fatigue load reductions are small, whereas the blade fatigue loads are reduced by 20% at low turbulence levels. For both deterministic and turbulent inflows, it is seen that the blade load reductions are penalized by increased load variations on the non‐rotating turbine parts. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献