简报燃气轮机涡轮导叶热管冷却效果对比研究     

占丽媛  李玉华  姜玉雁  唐大伟 《中国科学院大学学报》2014,31(6):846-850

以一种涡轮直叶片为研究对象,分别采用热管冷却和冲击冷却对其进行气热耦合数值模拟计算,对比分析两种冷却方式的效果.通过对叶片的表面温度、中截面的换热系数以及总体冷却效率的对比,分析结果表明,使用热管冷却时,叶片尾缘的温度分布更加均匀,转捩点附近低温区范围分布更广.在相同的主流条件下,热管冷却能达到甚至超过冲击冷却的效果.  相似文献   

基于DBNs风机故障检测方案设计     

王默玉  段利锋  李新颖  申晓留 《中国科技信息》2013,(22):128-131

状态监测对于了解风机的健康状况,从而制定相对应的检修方案至关重要.采用dbns对风机关键部位的温度参数进行分析和特征提取,生成在正常情况的评估出力值,通过比较评估值和实际出力情况来计算风机出现潜在故障的可能性,从而为工作人员制定检修工作部署提供决策辅助.  相似文献   

A fluid dynamic investigation of the Big Blade and Macon oar blade designs in rowing propulsion     

Nicholas Caplan  Trevor N. Gardner 《Journal of sports sciences》2013,31(6):643-650

Abstract

The purpose of this investigation was to examine the fluid dynamic characteristics of the two most commonly used oar blades: the Big Blade and the Macon. Scaled models of each blade, as well as a flat Big Blade, were tested in a water flume using a quasi-static method similar to that used in swimming and kayaking research. Measurement of the normal and tangential blade forces enabled lift and drag forces generated by the oar blades to be calculated over the full range of sweep angles observed during a rowing stroke. Lift and drag force coefficients were then calculated and compared between blades. The results showed that the Big Blade and Macon oar blades exhibited very similar characteristics. Hydraulic blade efficiency was not therefore found to be the reason for claims that the Big Blade could elicit a 2% improvement in performance over the Macon. The Big Blade was also shown to have similar characteristics to the flat plate when the angle of attack was below 90°, despite significant increases in the lift coefficient when the angle of attack increased above 90°. This result suggests that the Big Blade design may not be completely optimized over the whole stroke.  相似文献   

Influence of free surface,unsteadiness and viscous effects on oar blade hydrodynamic loads     

Alban Leroyer  Sophie Barré  Jean-Michel Kobus  Michel Visonneau 《Journal of sports sciences》2013,31(12):1287-1298

Abstract

Flow around a rowing blade is a very complex phenomenon, involving unsteady three-dimensional flow with violent motion of the free surface. However, in the literature, forces acting on blades are modelled using extreme and dubious simplifications. The aim of the present study was to evaluate the influence of free surface and unsteadiness (two physical characteristics that are commonly neglected when modelling loads on blades) as well as viscous effects. In fact, quasi-static approaches are often used, with no influence of the free surface effects. To conduct this study, computational fluid dynamics is used, supported by experimental results performed with a dedicated device reproducing a simplified rowing stroke in the towing tank. Comparisons show that both free surface flow and unsteadiness must be considered to capture the whole physics of the phenomenon accurately. In contrast, the viscous effects have a very limited influence.  相似文献   

龙滩水轮机座环工地加工机床安装调试     

张群 《四川工程职业技术学院学报》2010,24(2):28-32

龙滩水轮机座环工地加工机床是东电设备中心为龙滩电站水轮机座环工地加工开发的专用设备,按技术要求,龙滩水轮机座环在工地安装后必须对相关的安装面(4面1密封槽)进行整体加工,以消除变形和尺寸误差。本文主要介绍龙滩水轮机座环工地加工机床的设计原理、主要结构、厂内预装试加工情况、工地安装调试及加工过程。  相似文献   

轴流式水轮机转轮叶片密封装置漏油原因分析及其处理     

吴树林  解毅平  余天然 《长江工程职业技术学院学报》2009,26(1):42-43

分析了水轮机转轮叶片密封装置的结构特点及发生转轮叶片漏油、转轮体进水的原因,有针对性地制定工艺处理方案并进行实施,使水轮机安全稳定运行,以提高经济效益。为同类机组的漏油进水缺陷处理提供了尝试性的借鉴。  相似文献   

跨音斜流叶轮小叶片位置CFD分析研究     

杨晶晶  黄生勤 《大众科技》2012,(6):165-167

文章针对一个单级总压比为5的斜流叶轮,研究了小叶片在大叶片通道内不同的轴向及周向位置下对叶轮性能的影响;最终得出的结论是,在压比较高的情况下,小叶片的最佳轴向位置在大叶片的0.3倍全长处,周向位置则应取在槽道中间。  相似文献   

小微型轴流式水轮机改进设计     

陈泉开 《福建工程学院学报》2009,7(4)

基于提高水能转化效率、降低水电站维护成本,改进设计了转轮标称100cm的轴流式水轮机.主要包括核心部件转轮调桨装置和导水叶传动机构的改进设计以及采用反求技术和快速成型技术取得桨叶的三维实体造型和实物模型.小微型轴流调桨式水轮机经改进已定型生产,主要用于较低水头、较大流量的农村小微型电站.  相似文献   

湛江发电厂1号汽轮发电机组振动故障分析及处理     

全浩荣 《中国科技信息》2007,(11):111-113

本文对湛江电厂一台300MW汽轮机,在启动、运行中振动偏大的突出问题进行了探讨,介绍了振动原因分析、诊断和处理过程。  相似文献   

多泥沙河流水电站水轮机的抗磨蚀防护技术     

曹利刚 《杨凌职业技术学院学报》2011,10(3):47-50

由于水轮机磨损的预防和修复技术关系到电站的安全运行和经济效率,所以越来越多的受到了人们的重视。本文主要说明了水轮机磨蚀的机理和主要部位,总结分析我国水轮机磨蚀预防和修复存在的问题以及较为成熟的技术,详细介绍了两种效果较好的抗磨涂层的实际应用情况,并提出优化运行抗磨措施。  相似文献