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2006年08月24日

【期刊论文】Effects of Velocity Head and Momentum Exchange on Critical Stable Sectional Area of Downstream Throttled Surge Tank

杨建东, Xu Lai, Jiandong Yang, and Jianzhi Chen

,-0001,():

-1年11月30日

摘要

The velocity head and momentum exchange at the T-junction between the surge tank with a riser and the tail water tunnel of hydroelectric powerplants have been introduced by using the Gardel’s head-loss formula. The effects of the velocity head and momentum exchange on the critical sectional area of the downstream tank have been analyzed. With Thoma’s assumption, the critical stable sectional area of the downstream throttled surge tank is derived theoretically. The study shows that the velocity head has an unfavorable effect on water level stability in the downstream surge tank while the effect of the momentum exchange is positive. These two effects counteract. Thus, the critical sectional area of a downstream throttled surge tank is close to that of a corresponding simple surge tank. However, if the size and shape of a riser are optimized, the area of the downstream surge tank may be further reduced. It is also demonstrated that a downstream throttled surge tank can reduce electricity loss and easily meet the requirements of stability in large flow oscillations when compared to a simple downstream tank.

Hydroelectric powerplants, Tanks, Velocity head, Head loss, Moment distribution.,

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2006年08月24日

【期刊论文】CRITICAL STABLE SECTIONAL AREA OF DOWNSTREAM THROTTLED SURGE TANK

杨建东, Xu Lai, Jiandong Yang and Jianzhi Chen

Honolulu, Hawaii, USA, July 6-10, 2003,-0001,():

-1年11月30日

摘要

With the Thoma's assumption, the critical sectional area for flow stability of the downstream throttled surge tank is derived theoretically. The effects of the velocity head and momentum exchange at the Tee junction between the surge tank riser and the tail water tunnel on the critical sectional area of the downstream tank have been analyzed using the Gardel's head loss formula. The study shows that the velocity head has an unfavorable effect on the water level stability in the downstream surge tank while the effect of the momentum exchange is positive. Two effects counteract. Thus the critical sectional area of a downstream throttled surge tank is close to that of a corresponding simple surge tank. However, if the size and shape of a riser are optimized, the area of the downstream surge tank may be further reduced. It is also demonstrated that a downstream throttled surge tank can reduce electricity loss and meet the requirements of stability easily in large flow oscillations compared to a simple downstream tank.

critical stable sectional area, downstream surge tank, velocity head, momentum distribution

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2006年08月24日

【期刊论文】PHYSICAL SIMULATION OF TRANSIENT PROCESS IN CONDUITS OF HYDROPOWER STATIONS

杨建东, Jiandong Yang, Jinping Li and Yuehao Tang

Honolulu, Hawaii, USA, July 6-11, 2003,-0001,():

-1年11月30日

摘要

The transient process in the conduits of hydropower stations is a very complicated dynamic procedure coupled with fluid, machines, electricity, and even structure. The current methods used to analyze them separately cannot satisfy the design and the operation requirement of those large underground stations with long conduits. So it is necessary to develop a global physical simulation for the power station transients. As an initial discuss, this article focuses on the introduction of model similarity, model scale and some results about great fluctuation, small fluctuation and hydraulic interference in transient flow experiments.

physical simulation, transient process, similarity, model scale ratio

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2006年08月24日

【期刊论文】CFD技术在汽轮机定子线圈冷却水流量测量中的应用

杨建东, 肖惠民

热能动力工程,2004,19(6):601~604,-0001,():

-1年11月30日

摘要

利用超声波流量计检测大型汽轮发电机定子线圈冷却水流量大小,可直接判断冷却水的堵、漏,从根本上解决定子绕组冷却水堵塞问题,但超声波流量计用于弯管段测量时存在误差。本文利用CFD技术计算了某火电厂定子线圈内冷却水的流速分布,分析了管内流动对超声波测流的影响,获得了不同测点处流量误差的变化趋势。采用CFD技术可确定超声波流量计的最佳安装位置,为获得准确的流量提供理论依据。

超声波流量计, 弯管, 计算流体动力学(, CFD),

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2006年08月24日

【期刊论文】水电站进水口漂浮式拦污排张力计算

杨建东, 徐远杰, 陈辉春, 关江

水利学报,2005,36(3):303~308,-0001,():

-1年11月30日

摘要

水电站进水口漂浮式拦污排由若干浮箱链接成索状,可简化为柔系平面结构。将水流、风和波浪对拦污排浮箱的作用转化为链节点作用力,然后根据虚功原理导出描述拦污排平衡状态的非线性方程组,并采用迭代方法求得漂浮式拦污排轴线张拉形状和张力数值解。洪江水电站工程实例计算结果表明:拦污排形态和轴向张力分布规律受水流单独或与风、波浪组合作用的影响非常明显,不同运行工况呈现不同的形态,且张力一般呈非均匀分布,岸边支墩反力值大于坝前支墩反力值,张拉形态和张力分布与悬链线理论计算结果差别较大。尤其在不发电泄洪运行工况下,进水口水域主流方向变化显著、流速增大,拦污排将出现非稳定性态,可能产生流体诱发大幅度摆动。

水电站, 进水口, 漂浮式拦污排, 张力计算

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  • 杨建东 邀请

    武汉大学,湖北

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