共查询到19条相似文献,搜索用时 929 毫秒
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根据汽轮机检修工艺,对汽轮发电机组转子轴系的对中检测方法进行了研究,提出了轴系参数的检测方案及相关技术,开发了一种高灵敏度的容栅式位移传感器和基于M51单片机的SKRS-232C译码转换及数据采集智能装置,进而组成可用于汽轮发电机组检修中转子对中调试的自动检测系统。针对多转子系统轴系的对中参数调试问题,建立了调整关系分析模型。基于遗传算法提出一种数值分析方法,可有效解决多目标规划中搜索过程易陷入局部优化解和计算效率低等问题。此方法应用到汽轮机转子轴系对中调整方案的参数分析过程,可显著提高计算效率,有效减少调整工作量,为机组的提前装复和投产提供技术保障。 相似文献
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机组的安装误差、缸体变形、基础沉降和热膨胀不均等问题都会引起汽轮发电机联轴器中心偏移,在检修过程中需要对其进行调整。以图表形式编制汽轮发电机组轴系调整的过程,归纳出一种校对中心的精确计算方法,以某300MW抽凝式汽轮机大修中心调整过程为实例,验证该中心调整计算方法的有效性及其应用范围。并说明调整过程中应注意的事项,为同类型旋转机械安全运行提供技术参考。 相似文献
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多转子的轴系中心调整是一项复杂的工作。实际检修过程中,要经过多次计算,多次试验,并进行优化才能调整到位。针对此情况,引进了由实缸到半缸再到实缸的调整方案,以图表形式编制了汽轮发电机组轴系调整的快速计算方法。并以N335-16.18/538/538汽轮发电机组的轴系大修中心调整过程为例,探讨有关轴系中心计算调整标准的制定,调整计算方法及调整过程中应注意的事项。最后介绍了D600A型汽轮机联轴器螺栓紧固的工艺流程及矢量图法,以期为同类机组的检修调整提供参考。 相似文献
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在论述汽轮机组轴系安装重要性的基础上,结合实际安装经验,对转子安装前的检查项目进行了简要说明,探讨了对轮找中心及其调整方法,并对轴系连接中出现的问题提供了1种分析和处理方法,可供从事电站安装的技术人员参考。 相似文献
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以某百万千瓦级核电半速汽轮发电机组为研究对象,采用转子动力学的专业分析软件ARMD,建立弹簧基础-轴承-转子的动力学模型,通过动力学计算获得轴系动力学特性,现场实测轴系临界转速与计算值吻合,验证了该计算模型的准确性。在此基础上计算了发电机密封瓦热不平衡导致的振动响应,发现其振动变化主要集中于发电机转子处,密封瓦动静摩擦仅是轴系振动波动问题的直接影响因素之一,而非根本原因。同时对不同运行状态下密封瓦油膜受力进行分析,发现轴向倾斜对密封瓦受力影响最大,因此机组在检修调整过程中应保证加工及安装工艺,严防密封瓦运行过程中出现轴向倾斜。 相似文献
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透射电子显微镜(transmission electron microscopy,TEM)在工作状态时要求精确的合轴,电子枪作为TEM电子光学系统主要部件之一,要求电子源必须与镜筒中整个电磁透镜系统严格合轴,否则会造成到达样品的电子束流减少,引入球差等不良影响。在操作中灯丝像的对称性是判断电子枪是否合轴的重要判据。研究了TDX-200透射电子显微镜灯丝像的调节过程,给出了透射电子显微镜灯丝像的具体调节步骤,并通过课题室透射电子显微镜TDX-200进行了实际验证。 相似文献
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Yu Hongbin Zhou Guangya Chau Fook Siong Wang Shouhua 《IEEE journal of selected topics in quantum electronics》2009,15(5):1317-1322
A versatile lens with transformable-type and tunable-focal-length characteristics has been presented. The conventional punching technology is adopted to fabricate the lens structure due to its inherently high direction-holding capability. As a result, the alignment between two ends of the lens can be easily achieved without requiring complicated process. At the same time, soft lithography is used to realize structure similar to liquid-filled lens except the working medium being air rather than liquid acting as a tuning mechanism. These two parts are eventually combined together with bonding under oxygen plasma activation. With this design, large flexibility in performance tuning will be added to the lens, which has been experimentally demonstrated in beam shaping and imaging applications. 相似文献
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步进驱动系统的高精度闭环控制 总被引:5,自引:0,他引:5
为实现经济化高精度数控加工,提出了步进驱动系统的高精度闭环控制方法和基于该方法的新型闭环步进位置控制系统。该系统的重要特点是既有全闭环系统的控制精度,又有开环系统的稳定性,且应用范围很广,可对各种类型的数控机床实现以高精度,高稳定性和优良的动态性能为特征的全闭环位置控制。 相似文献
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Hideo Furuhashi Lizhong Zhou Jingnan Liu Akihito Matsuo Yoshiyuki Uchida 《Electrical Engineering in Japan》2002,139(2):46-51
In the lithographic processes of VLSIs, high setting accuracies between masks and wafer are required. The methods using moiré signals obtained by gratings were found to give very high alignment accuracies. In this paper, influences of the inclination of gratings for the alignment accuracies in modified and differential moiré systems have been investigated. The moiré signals and the alignment point have been calculated using computer simulation. As a result, it has been shown that the effects are small and the inclinations do not affect alignment accuracies in the moiré alignment systems. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 46–51, 2002; DOI 10.1002/eej.1152 相似文献
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捕获、对准、跟踪系统是空间激光通信系统的关键技术,是通信链路建立的前提。而视轴初始指向作为捕获系统中的第一步,是能否成功捕获、捕获概率大小以及捕获时间长短的决定性因素。为了快速建立空间激光通信链路,通过分析初始指向技术的组成与工作原理,建立了初始指向系统模型。提出了初始指向系统的视轴标校方法,且根据误差分析方法得到了系统指向精度。实验结果表明,该指向系统可以快速地建立空间激光通信链路,且指向精度高,验证了该指向系统的正确性与可行性。 相似文献
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基于最小二乘法的高压直流输电系统可靠性灵敏度分析 总被引:3,自引:1,他引:2
对高压直流(HVDC)输电系统进行可靠性灵敏度分析可以辨识系统的薄弱环节,对改善系统可靠性具有重要意义.文中提出一种分析HVDC输电系统可靠性灵敏度的方法:用最小二乘法拟合HVDC输电系统可靠性指标随元件可靠性参数变化的曲线,并根据拟合曲线即可得到元件对系统可靠性的灵敏度.当HVDC元件的可靠性参数发生变化后,为了快速估算出该参数对应的灵敏度,提出灵敏度曲线的概念,并推导了其解析表达式.对一单12脉接线HVDC输电系统进行灵敏度分析,证实了该方法的可行性和有效性. 相似文献
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Improved Circularity Metrology of Small Cylindrical Workpieces by the Segmenting-stitching Technique 下载免费PDF全文
To address the alignment and measuring force problem in the segmenting-stitching technique for the circularity metrology of small cylindrical workpieces (diameter less than 1.5 mm and length less than 10 mm), a magnet combination jig method is proposed. A small round magnet is attached between the round magnetic jig and small cylinder, and the other end of the small cylindrical workpiece is attached to some cylindrical magnets. Thus, the smaller cylinder can be put in the V-groove and measured successfully with the magnet combination. For ver-ifying the advantage of the magnet combination jig, four measurement quality evaluations are proposed: the circumferential deviation of neighbor arc contours, radial deviation of neighbor arc contours, angle of inclina-tion between the V-groove and small cylinder, and curvature of the obtained arc. The results show that the matching coefficient is enhanced by 98%, the Euclidean distance of overlap parts of neighbor arc contours is reduced by 68%, the position error is reduced 27%, and the average curvature of the arc contours is improved. It can be concluded that the measuring quality can be enhanced prominently by this magnet combination method for the segmenting-stitching method. 相似文献