共查询到18条相似文献,搜索用时 125 毫秒
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大型核电汽轮机焊接转子残余应力数值模型研究 总被引:2,自引:0,他引:2
大功率汽轮机是核电站中的关键动力设备,转子是核电汽轮机中的关键部件,其安全可靠性是汽轮机正常运行的重要保证,由于锻件尺寸的限制,大功率核电汽轮机广泛采用焊接转子.焊接过程中产生的转子热应力和残余应力将可能导致焊缝及其附近区域发生过量变形,诱导裂纹萌生,并影响焊接件的疲劳强度.建立了焊接转子的轴对称和三维有限元模型,研究了大型核电汽轮机焊接转子的变形和残余应力分布规律,获得了焊趾上各点的应力和最大残余应力及其发生区域.所得结果对控制焊接转子质量和结构优化设计具有重要的指导意义. 相似文献
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4月8日,南中国机械工业联合会举办的东汽核电汽轮机低压焊接转子鉴定会上,百万千瓦核电焊接转子的研制顺利通过专家鉴定委员会鉴定。 相似文献
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汽轮机转子初始裂纹高周疲劳安全性分析方法及其在焊接转子中的应用 总被引:1,自引:1,他引:0
介绍了汽轮机转子高周疲劳寿命的设计方法.提出了汽轮机转子初始裂纹高周疲劳安全性的分析方法,转子高周疲劳的平均应力σm、应力幅σA和应力强度因子范围AKI的计算方法以及转子钢疲劳裂纹扩展门槛值△KR的经验计算公式.给出了汽轮机转子初始裂纹高周疲劳安全性的分析思路、分析方法、评价判据以及半转速1 000 MW核电汽轮机焊接低压转子的高周疲劳安全性分析应用实例.结果表明:转子初始裂纹高周疲劳分析方法能够应用于汽轮机转子的安全性评价,并可以为汽轮机转子的结构优化和长周期安全运行提供依据. 相似文献
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AP1000作为未来国内发展的主力核电堆型,比现有二代半堆型功率更大、寿命更长,且有内陆应用要求等新特点,其发展对汽轮机设计开发提出了新的要求。介绍了上海电气电站设备有限公司上海汽轮机厂(以下简称STP)在AP1000核电汽轮机设计中的创新设计特点,通过对核电汽轮机关键部件60年寿命设计、核电汽轮机及基础整体抗震性能评估、核电汽轮机低压焊接转子设计、核电汽轮机长叶片系列化设计等方面的介绍,旨在探讨如何提高汽轮机的运行寿命、安全性和经济性。这些创新设计基于大量的试验计算研究,其研究结果将对我国AP1000核电汽轮机的自主化设计及未来核电产品的出口起到积极的推动作用。 相似文献
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大功率汽轮机是火电和核电站中的关键动力设备,转子则为汽轮机中的关键部件,其安全可靠性是汽轮机正常运行的重要保证。采用焊接转子可作为解决大尺寸转子制造的有效手段,转子焊接过程中的热应力及残余应力是评估转子安全性的重要参数。文中以三维热弹塑性有限元计算理论为基础,对于一个模型转子,建立了其焊接过程热应力耦合模型,获得了焊接过程中热影响区热应力的详细分布以及随时间的变化、转子焊接冷却完毕时残余应力分布及应力峰值。研究结果表明,焊接导致的高残余应力分布于焊缝区。本文的结果对控制焊接转子质量具有重要的参考价值。 相似文献
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甩负荷时的大惯性和水膜闪蒸现象使得核电汽轮机比常规汽轮机有更大的超速危险性 ,所以对核电汽轮机甩负荷动态特性的研究对控制系统设计和保证机组的安全有重大意义。该文从工质流动、蓄积、作功、状态变化的机理角度建立了国产 60 0 MW核电汽轮机的数学模型 ,并特别建立了水膜蒸发量、吸热量以及附加做功的计算模型 ,以反映甩负荷时的水膜闪蒸现象。文中应用数学模型对不同控制方式下机组的甩负荷动态过程进行了仿真计算和比较 ,特别探讨了水膜闪蒸、中间再热主汽门的关闭和泄漏对超速的影响。图 6参5 相似文献
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Sameh Shaaban 《国际能源研究杂志》2017,41(4):540-552
Wells turbines provide a practical solution for wave energy harvesting. The low aerodynamic efficiency of Wells turbines tangibly reduces their output power. Both the turbine efficiency and output power depend on the turbine solidity. The turbine solidity decreases from rotor hub to rotor tip for the commonly used rotors with constant chord‐length blades. The present work introduces a novel Wells turbine rotor geometry. This geometry was obtained by numerically optimizing the rotor's radial solidity distribution. The turbine performance with different rotor geometries was numerically simulated by solving the three‐dimensional Reynolds‐averaged Navier–Stocks equation under incompressible and steady state flow conditions. Simple and multi‐objective optimization were implemented in order to obtain the optimum rotor geometry. The present work showed that an improved turbine performance can be achieved by optimizing the turbine radial solidity distribution. Two different optimized rotor geometries were obtained and presented. The first rotor geometry improved the turbine efficiency by up to 4.7% by reducing its pressure drop. The second rotor geometries enhanced the turbine output power by up to 10.8%. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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随着新能源的不断应用.核电技术得到逐步的推广,作为高端市场的核电产品,其制造技术都被国外垄断。核电汽轮机的国产化正在起步。转子是核电汽轮机的核心部件,其加工难度集中在叉型轮槽的车削上。由于槽深、壁薄,车削时极易发生变形,如何控制车削变形,保证加工质量,是制造技术人员研究的重点。 相似文献
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The aim of this investigation was to develop an environmentally friendly nano-hydraulic turbine utilizing waterfalls. A model of an impulse type hydraulic turbine constructed and tested with an indoor type waterfall to arrive at an optimum installation condition. Effects of an installation parameter, namely distance between the rotor and the waterfall on the power performance were studied. The flow field around the rotor was examined visually to clarify influences of installation conditions on the flow field. The flow visualization showed differences of flow pattern around the rotor by the change of flow rate and rotational speed of the rotor. From this study it was found that the power performances of the rotor were changed with the distance between the rotor and the waterfalls. The maximum power coefficient of this turbine is approximately 60%. Also, to respond to changes in the waterfall flow rate, we placed a flat plate on the upper side of the rotor to control the water flow direction. As a result, we found that the coefficient of this turbine is increased with the flow rate and power could be obtained even when the flow rate changed by 3.5 times if the plate was placed on the upper side of the rotor. Although the power coefficient decreased when the plate was installed, the power coefficient still is from 53 to 58%. 相似文献