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下环间隙对混流式水轮机转轮进口的影响 总被引:1,自引:0,他引:1
为分析混流式水轮机下环间隙对水轮机稳定性的影响,通过对含下环间隙的凤滩电站原型水轮机进行三维全流道数值计算,分析了下环间隙对水轮机转轮进口压力机速度的影响,得出了不同密封间隙值下间隙内部压力的变化规律。为水轮机组在设计和运行时避免振动提供了一定的参考依据。 相似文献
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针对小木岭二级水电站高水头混流式机组顶盖水压过高的问题,通过对机组实际运行数据和转轮结构的分析并结合理论分析,提出了改变转轮上冠止漏环型式并适当减小止漏环间隙以增强止水效果的技术改造方案,结果表明技改方案是成功的。 相似文献
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成安 《电网与水力发电进展》2007,23(1):18-20
介绍了安康水电站四台机组水轮机过流部件损坏情况,分析了损坏的原因,并针对各台机组的破坏情况进行了修复、改造处理,提出了预防和改进建议。 相似文献
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为了系统地研究负倾角转轮机组在额定出力工况及50%出力工况下机组不同位置的压力脉动特性,以某抽水蓄能电站负倾角转轮为基础,通过三维建模软件UX建立全流道计算域,然后采用ANSYS ICEM和TURBOGrid划分全流道结构网格;并采用ANSYS CFX进行数值模拟得到各压力监测点压力脉动信号。计算结果表明,在两种工况下,机组压力脉动主频均为叶片倍频;负倾角转轮机组压力脉动振幅沿负z方向明显升高;机组压力脉动振幅随流动方向先升高后降低,在无叶区位置达到最大值。 相似文献
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针对水轮机转轮叶片出现裂纹会严重威胁水电厂的安全经济运行,通过对广东省流溪河水电站#2机组混流式转轮叶片出现裂纹原因的分析,介绍了大修时采用着色无损探伤检查法对转轮叶片进行及时处理缺陷的过程.结果表明,该措施效果较好,可阻止裂纹的延伸,消除事故隐患,可供借鉴. 相似文献
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对转轮常用材料ZG20SiMn进行JICda/dN及△kth测定,初步建立了转轮裂纹扩展模型,并对已运行转轮进行了计算,结果与实际相符。图5表7参3 相似文献
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采用胸腔穿刺抽去胸水后,腔内注射顺铂,联合支气管动脉化疗治疗肺癌并胸腔积液40例。结果10例完全缓解,20例部分缓解,总有效率75%。对延长患者生存期,减轻痛苦,提高生活质量,是一种较好的治疗方法。国内未见报道过,值得临床应用。 相似文献
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结合工程实践讨论了多级水封器设计高度的两种计算方法,并采用动态分析方法得出了水封器高度的计算公式,该公式简单、准确,适用于多级水封器的设计。 相似文献
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Excessive erosion of the low-pressure rotor end gland seal of a 25 MWe geothermal turbine produced a partial loss of turbine vacuum that degraded cycle efficiency. This study used computational fluid dynamics (CFD) to identify the causes of erosion and the optimal steam seal system flow conditions for reducing the erosion problem. The predictions were based upon a numerical calculation using a commercial CFD code (Adapco Star-CD) to model the rotor end gland seal with a steam flow containing hard solid particles. The results confirmed that flow conditions play a major role in rotor gland seal erosion. By changing steam seal flow pressures to vary flow, it was confirmed that there is a threshold seal flow condition below which erosion does not occur, or is minimized. Optimizing the rotor end gland seal supply pressure and intercondenser pressure reduced the turbulent flow kinetic energy by 49%, with a corresponding decrease in the erosion rate of the rotor gland seal surface. The erosion rate is related directly to the particle velocity and turbulent flow kinetic energy. Recommendations are provided for adjusting the rotor end gland seal system to avoid erosion. 相似文献
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OnTheAnalysisofLabyrinthSealFlowInducedVibrationbyOscillatingFluidMechanicsMethod¥ChenZuoyi;JingYouhao;SunYongzhong(Death.ofT... 相似文献
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Ning WU Wugao ZHANG Zhen HUANG 《Frontiers of Energy and Power Engineering in China》2008,2(3):279-284
The resistance of many kinds of rubber materials to dimethyl ether (DME) was studied. Both the mass and volume change of rubber
materials, which were put in DME and then exposed to the air for different periods of time were measured. The results show
that fluorine rubber (FKM), silicone rubber (SIR), and nitrile rubber (NBR) are unsuitable as seal materials for DME engines.
Common polyvinylchloride (PVC) dissolved completely in DME, which has almost no impact on vulcanizing nylon material. The
constitution of ethylene propylene terpolymer rubber (EPDM) has a major impact on its resistance to DME. A kind of EPDMwith
good resistance to DME was found, whose reliability was validated by 100 hours of DME engine operation.
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Translated from Journal of Shanghai Jiaotong University, 2006, 40(8): 1257–1261 [译自: 上海交通大学学报] 相似文献