共查询到17条相似文献,搜索用时 293 毫秒
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660MW超超临界汽轮机高压转子的高温蠕变强度分析 总被引:1,自引:0,他引:1
为了研究在高温下某660 MW超超临界汽轮机高压转子的蠕变强度,利用有限元计算方法分析了转子在额定工况下的温度和应力分布,并采用幂率模型和孔洞长大机理预测了该转子在2×105h工作中的蠕变行为,研究结果表明:在额定工况下,转子最高内应力低于屈服极限,处于纯弹性变形状态;转子内大部分区域温度在300~600℃,已进入蠕变温度范围.蠕变与热弹性耦合分析表明:蠕变会引起转子内部应力的重新分布,转子前轴封圆弧段的蠕变应变较高,而且多轴应力对该区域蠕变韧度的影响明显,应当引起足够重视. 相似文献
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汽轮机强度研究某些新进展的概述 总被引:1,自引:0,他引:1
介绍了汽轮机部件强度和寿命研究的某些新进展 ,综述了近几年来汽轮机部件的静强度和刚度、叶片和叶根的动强度、有限元分析、强度可靠性设计、低周疲劳寿命、蠕变寿命、疲劳和蠕变交互作用下的寿命、安全寿命等方面国内开发的一些新技术手段和取得的新成就。本文还提出了汽轮机部件强度和寿命计算技术的一些发展动向 相似文献
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汽轮机隔板高温蠕变寿命评估方法的研究 总被引:2,自引:0,他引:2
针对现役引进型机组高温蠕变现象难于正确评估的情况,提出了根据机组历次大修记录的变形数据和有限元计算相结合的方法得到材料蠕变参数.采用该方法对某电厂600 Mw机组T11 级隔板的高温蠕变变形问题进行了分析研究,并应用商用软件对隔板在继续运行中的变形和应力情况作出了预测和评估.结果表明:隔板最大应力产生的位置在隔板外环叶片的出汽侧,靠近中分面边缘叶根、叶片的出汽边处,其值为160 MPa,按每年连续运行8 000 h计算,隔板的使用寿命约为30年,与制造商提供的设计寿命一致,得出了机组在一个大修期内不必立即更换隔板的结论,节约了维修费用,为汽轮机或燃气轮机高温部件的蠕变寿命的评估提供了一种实用方法. 相似文献
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目前汽轮机叶片设计和安全性考核主要采用的是以许用应力为基准的静强度准则和以安全倍率为基准的动强度准则,随着汽轮机设计制造水平的提高,尤其是近年来在超临界和超超临界大功率汽轮机中广泛采用具有复杂阻尼结构的长叶片,该方法已经表现出越来越多的局限性,建立一套从寿命损耗角度评估叶片安全性的方法十分必要。总结了近年来国内外在叶片寿命评估相关研究如静态应力分析、动态应力分析、叶片高周和低周疲劳寿命分析以及叶片水蚀疲劳分析等4个方面的研究进展,并对进一步深入研究提出了一些思路和方法。 相似文献
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A way of calculating the overall equivalent heat transfer coefficient of wheel rims of large capacity steam turbines is presented. The method and formula to calculate the mean forced convection heat-transfer coefficient of the surface of the blade and for the bottom wall of the blade passage, are introduced. The heat transmission from the blade to the rim was simplified by analogy to heat transmission in the fins. A fin heat transfer model was then used to calculate the equivalent heat transfer coefficient of the blade passage. The overall equivalent heat transfer coefficient of the wheel rim was then calculated using a cylindrical surface model. A practical calculation example was presented. The proposed method helps determine the heat transfer boundary conditions in finite element analyses of temperature and thermal stress fields of steam turbine rotors. 相似文献
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文章针对不同倾斜角度,对斜齿枞树型叶根透平叶片的叶根和轮槽的接触状态进行了分析。通过三维建模和有限元分析,发现斜齿枞树型叶根各齿栽荷分布随角度变化不大,且各齿栽荷分布没有直齿枞树型各齿载荷分布均匀。叶根最大应力随叶根倾斜角增大而增大,对低温区叶片来说,由倾斜角度增大引起的叶片应力增大可忽略不计。但对于高温区叶片,减小倾斜角度以使叶片应力降低是很有积极意义的。本研究可为枞树型叶根的设计提供理论支持。 相似文献
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Jinyuan Shi Zhicheng Deng Yu Yang Ganwen Jun 《Frontiers of Energy and Power Engineering in China》2008,2(1):20-24
A way of calculating the overall equivalent heat transfer coefficient of wheel rims of large capacity steam turbines is presented.
The method and formula to calculate the mean forced convection heat-transfer coefficient of the surface of the blade and for
the bottom wall of the blade passage, are introduced. The heat transmission from the blade to the rim was simplified by analogy
to heat transmission in the fins. A fin heat transfer model was then used to calculate the equivalent heat transfer coefficient
of the blade passage. The overall equivalent heat transfer coefficient of the wheel rim was then calculated using a cylindrical
surface model. A practical calculation example was presented. The proposed method helps determine the heat transfer boundary
conditions in finite element analyses of temperature and thermal stress fields of steam turbine rotors.
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Translated from Journal of Power Engineering, 2007, 27(2): 153–156 [틫自: 뚯솦릤돌] 相似文献
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The optimized structure strength design and finite element analysis method for very high pressure (VHP) rotors of the 700°C ultra-super-critical (USC) steam turbine are presented. The main parameters of steam and the steam thermal parameters of blade stages of VHP welded rotors as well as the start and shutdown curves of the steam turbine are determined. The structure design feature, the mechanical models and the typical position of stress analysis of the VHP welded rotors are introduced. The steady and transient finite element analysis are implemented for steady condition, start and shutdown process, including steady rated condition, 110% rated speed, 120% rated speed, cold start, warm start, hot start, very hot start, sliding-pressure shutdown, normal shutdown and emergency shutdown, to obtain the temperature and stress distribution as well as the stress ratio of the welded rotor. The strength design criteria and strength analysis results of the welded rotor are given. The results show that the strength design of improved structure of the VHP welded rotor of the 700°C USC steam turbine is safe at the steady condition and during the transient start or shutdown process. 相似文献
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