共查询到20条相似文献,搜索用时 125 毫秒
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欧阳伟基 《中国锅炉压力容器安全》2010,(1):18-21
本文通过广东省1000MW超超临界直流锅炉的蒸汽吹管实施情况介绍,详细介绍了降压吹管在超超临界直流锅炉的应用、吹管系统特点、吹管实施控制过程、参数变化情况、吹管发现问题等。 相似文献
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本文结合江西新昌电厂新建工程2×660 MW超超临界直流锅炉起动调试阶段不熄火降压法吹管的情况,对影响汽温的一些关键因素进行了分析和总结,为防止类似的超超临界直流锅炉降压吹管出现汽温超温情况提供一些参考. 相似文献
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二次再热锅炉因增加一级再热器,点火吹管时系统更加复杂,过热器系统蓄热量明显不足,导致目前国内大部分二次再热锅炉吹管时都选择分阶段降压吹管,少部分锅炉选择稳压吹管.目前国内大部分超超临界机组都采用降压吹管法,此方法更加适合国内机组的基建情况.本文以某超超临界二次再热机组为例,分析二段降压吹管法中的最优法.最后表明利用一次... 相似文献
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600MW超临界锅炉降压吹管操作方法探讨 总被引:1,自引:0,他引:1
超临界锅炉采用不熄火不停泵的降压吹管方法是目前国内机组普遍采用的方法,而由于带循环泵的启动系统的复杂性使得吹管操作比较繁琐.目前国内普遍存在着吹管操作方法不规范的现象,对炉水循环泵安全存在严重的影响.根据某超临界锅炉的吹管工作实践,对带循环泵的启动系统的超临界锅炉吹管操作方法进行探讨,重点对吹管过程中启动系统的运行和控... 相似文献
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超临界锅炉采用不熄火不停泵的降压吹管方法是目前国内机组普遍采用的方法,而由于带循环泵的启动系统的复杂性使得吹管操作比较繁琐.目前国内普遍存在着吹管操作方法不规范的现象,对炉水循环泵安全存在严重的影响,根据某超临界锅炉的吹管工作实践,对带循环泵的启动系统的超临界锅炉吹管操作方法进行探讨,重点对吹管过程中启动系统的运行和控制方式提出具体操作方法. 相似文献
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针对某吸气过滤器各部件结构的应力仿真计算和强度分析问题,根据有限元理论和方法建立了有限元计算模型,采用ANSYS Workbench进行应力计算,得到了各部件的变形云图和应力分布云图。在应力分析的基础上,根据材料力学的相关理论和压力容器的相关标准对模型进行应力评定和强度分析,应力计算结果显示,有两个部件不能满足强度要求。对两个问题部件进行结构优化,优化后的所有部件结构均能满足强度要求,为吸气过滤器材料成本的降低提供了一种有效的方法。 相似文献
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为研究某左右不对称灯泡贯流式厂房结构在静动力荷载作用下的位移、应力分布规律,采用三维有限元动力反应谱法对其进行抗震分析,计算中采用完全二次项组合(CQC)法考虑双向的扭转耦联作用,应用Westergaard公式考虑地震动水压力。结果表明,该厂房位移应力分布合理,可为同类工程提供参考。 相似文献
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碗米坡预应力闸墩三维有限元分析 总被引:1,自引:0,他引:1
应用三维有限元数值分析方法对坝基、坝体、闸墩、混凝土锚块及预应力锚索在内的整体模型进行应力和变形计算。研究结果表明,预应力闸墩具有整体稳定性,在各种荷载的组合效应下整个墩体的变形和应力分布满足设计要求。 相似文献
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Heat transfer, thermal and residual stress distribution were numerically determined by using the finite element method for a butt-welded pipe. A mechanical stress relieving (MSR) treatment which was frequently used in the fabrication of pressure vessels instead of the post-weld heat treatment (PWHT) was also simulated to investigate its effect of reducing the residual stress in the welded zone by a mechanical loading. Stress redistribution in a butt-welded pipe during MSR loading was studied numerically in three different loading conditions. In this study, the inner loading case has the strongest effect on the residual stress reduction behavior among the three loading cases. The reduction quantity of the tensile residual stress near the weld centerline, when MSR treatment of the inner loading case is used after pipe welding, linearly increases when compared with the magnitude of the applied loads. When the MSR treatment is performed after pipe welding, the load case is a tensile stress if the reduction of the peak value of tensile stresses is strong. On applying a compressive MSR load to the weldment, the peak value of the compressive residual stresses are reduced quickly. 相似文献
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H.T. Corten 《International Journal of Pressure Vessels and Piping》1973,1(4):299-316
The determination of the fracture toughness properties of pressure vessel materials is of increasing importance in reducing the risk of low stress fracture. This paper reviews the present status of testing methods and indicates their ranges of application. 相似文献
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以新疆某心墙浇筑式沥青混凝土材料为例,对其进行动三轴试验,研究了浇筑式沥青混凝土动应力-应变骨干曲线的变化规律及不同围压、主应力比和振动频率对浇筑式沥青混凝土动应力-应变骨干曲线的影响,并基于正交设计方案,以动应力为考察指标,分别采用极差和方差分析法分析了围压、主应力比和振动频率的敏感性。试验结果表明,浇筑式沥青混凝土材料动应力-应变骨干曲线变化基本符合双曲线规律,围压和主应力比对动应力-应变骨干曲线的影响较大,随围压和主应力比的增加,沥青混凝土的动强度明显增大;振动频率对浇筑式沥青混凝土材料动应力-应变骨干曲线的影响较小,不同频率下的骨干曲线均集中于狭窄的分布带内,高振动频率的动强度略大于低频下的动强度。围压和主应力比对动应力的影响比较显著,是影响动应力的主要因素,振动频率对动应力的影响不显著,影响因素的敏感性依次为围压、主应力比和振动频率。 相似文献
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Thermally grown silicon dioxide is commonly used in high-efficiency mono-crystalline silicon solar cell designs as a diffusion mask, electroless plating mask, passivation layer or as a rudimentary anti-reflection coating. Some of these device designs also use upright random texturing, to minimize front surface reflection, in combination with thermally grown silicon dioxide layers. The volume expansion associated with oxidation, generates large stresses on the silicon substrate when oxidizing sharp surface features. If this stress exceeds the fracture stress of silicon, defects are generated within the bulk region. This paper reviews oxidation-induced stress, and highlights two techniques for reducing lifetime degradation during the growth of silicon dioxide on textured wafers: (i) reducing the generation of stress, and (ii) decrease the relaxation time of the silicon dioxide layer. This paper experimentally investigates, and evaluates, several practical methods for implementing these techniques on upright random textured p-type float zoned silicon using photoconductance lifetime. 相似文献