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51.
52.
通过数据监测,对右江水电厂4台机组水导轴承运行中出现瓦温缓慢上升的问题进行分析,查找原因,并提出了不同的技术改造方案,对比后择优实施,既保证了水电厂的长期安全稳定运行,又为企业节省了成本. 相似文献
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该文介绍攀成钢180ACCU轧管机的基础自动化系统设计与开发,该系统采用基于西门子S7—400PLC的解决方案。文中描述了该轧管机组的工艺流程和控制系统的功能需求,并从系统选型、系统结构及软硬件配置、应用软件开发和功能特点等方面进行了详细阐述。该方案对同类型轧管机控制系统的设计与开发具有较高的参考价值。 相似文献
55.
曾灵 《自动化与仪器仪表》2008,(5)
主要介绍了带钢热连轧厚度控制中采用能耗曲线的方法,对轧机的负荷分配进行分析和设计,详细论述了能耗曲线的建立过程以及运用于实际生产过程中的轧制力分配和辊缝分配的控制方案,并给出了它们各自具体的控制原理、计算公式以及程序框图。该负荷分配方法用于在线,有较好的使用效果。 相似文献
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Li S.-M.Li S.-S.Chang D.-G. 《工程设计学报》2017,(2):182-186
To find out the causes of vibration and noise of the trigeminal universal joint which appeared in the installation and use process, the additional moment distribution with the varies of the input shaft angular and the deflection angle was analyzed. Kinematics diagrams of the trigeminal universal joint when the output shaft installed by single radial bearing or twin radial bearing were established. The system coordinates were established under the two installation ways, and the motion equations were established by the direction cosine matrix tools. It indicated that the trigeminal universal joint installed by the single radial bearing was an approximately isometric speed transmission, and was a constant velocity transmission with twin radial bearing installed. Furthermore, the additional moment component on the input shaft and the output shaft was analyzed under the two installation ways. According to the virtual displacement principle, the additional moment on the tripod universal joint when the output shaft installed by twin radial bearing and single radial bearing were determined. When installed by single radial bearing, the deflection moment exists and the vibration frequency of additional moment was three times of the input shaft as a sine curve. The variation trend of the additional moment was straight up with the increase of deflection angle. When installed by twin radial bearing, the deflection moment was zero and the additional moment increased gradually with the increase of deflection angle but did not fluctuate. The analysis revealed that additional moment existed in the trigeminal universal joint system under both installation ways would produce bending vibration. This study is of great significance to study the causes of vibration and determine the nonlinear dynamics of the system. 相似文献
58.
Wire + Arc Additive Manufacturing 总被引:1,自引:0,他引:1
S. W. Williams A. C. Addison J. Ding G. Pardal P. Colegrove 《Materials Science & Technology》2016,32(7):641-647
Depositing large components (>10?kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to low and medium complexity parts. A variety of components have been successfully manufactured with this process, including Ti–6Al–4V spars and landing gear assemblies, aluminium wing ribs, steel wind tunnel models and cones. Strategies on how to manage residual stress, improve mechanical properties and eliminate defects such as porosity are suggested. Finally, the benefits of non-destructive testing, online monitoring and in situ machining are discussed. 相似文献
59.
Wenyuan Li Zhiyong Chen Jianrong Liu Shaoxiang Zhu Guoxin Sui Qingjiang Wang 《材料科学技术学报》2019,35(5):790-798
Rolling texture and its effect on tensile properties of Ti60 alloy plates were investigated in the present study. The plates wereβ-rolled at 1070℃ and(α+β)-rolled at 980℃, using uni-directionally rolling(UDR) and cross-directionally rolling(CDR) processes, respectively.β-rolled plates exhibited weak textures, which were attributed to the dispersive orientations of secondary α during the β→α phase transformation. Strong deformation textures formed in(α+β)-rolled plates as a result of slipping mechanisms: the strong T-type texture in UDR plate was related to {10 1 0}[11 2 0] slipping, while the B-type texture in CDR plate was relevant with {0001}[11 2 0] slip. Strong T-type textures led to anisotropic tensile properties. B-type textures would decrease such an anisotropy. The(α+β)-CDR process was found to be a candidate process for reducing anisotropy of Ti60 alloy plates. 相似文献
60.
针对目前汽轮机组振动的特点,将振动信号分为两类,即轴振(相对振动)和瓦振(绝对振动)。首先分析了汽轮机组的振动概况及其对机组的影响;然后分别介绍了机组振动的测量和分析方法。具体地从传感器谈起,解释了机组的轴振和瓦振的不同测量原理。针对振动的三要素即振幅、频率及相位分别做了介绍;最后以300MW机组为例,说明其振动测点的一般布置。 相似文献