用附加动量理论分析齿墩与消力池联合消能机理

用“附加动量”水跃理论分析齿墩与消力池联合应用的消能机理 ,用跃后水深、水跃长度或单宽水跃容积减少的百分数 ,估计新增消能设施的经济效益。并通过模型试验验证了消能的理论分析 ,计算了新增设施的消能量、跃后水深、水跃长度或单宽水跃容积减少的百分数。结果表明 :采用齿墩设施 ,可增进消力池的消能作用 ,并取得显著的经济效益 ,达到了附加动量水跃理论所预期的效果     

清远水利枢纽消能防冲问题试验研究

消能防冲是枢纽的安危所系,由于清远水利枢纽工程所处的北江下游河道受人为采砂的影响,河道水位连年下切,枢纽的消能防冲设计受到高度重视。对此利用宽水槽断面模型,在定床模型试验研究中对消能工体型进行多方案优化并确定了推荐方案,在下游局部动床试验中对推荐方案在各种工况下的闸下冲刷情况进行研究,分析消能防冲设计的安全性及可靠性。试验研究解决了该平原河道大型水闸枢纽消能防冲的关键技术难题,试验推荐方案为工程设计所采纳。研究成果可供平原河流大型水闸枢纽消能防冲设计借鉴和参考。     

具有隔板容器中液体晃荡的数值模拟

在容器中装置隔板来抑制液体晃荡是一种常见的工程措施。此文针对具有隔板的矩形容器中液体晃荡问题,采用时域高阶边界元方法建立了自由水面满足完全非线性边界条件的数学模型。求解中采用了半混合欧拉-拉格朗日方法追踪流体瞬时水面,并运用四阶龙格库塔方法更新下一时间步的波面和速度势。通过与文献的数值结果的对比,验证了本模型的准确性。通过大量数值试验,研究了隔板位置、尺寸和形式等因素对容器内晃荡液体运动特性、动力特性和容器固有频率的影响。     

导流洞出口布置形式及消能方式试验研究

以淋溪河施工导流模型为依托,重点研究导流洞出口布置形式及出口消能形式对下游冲刷、下游沿岸流速流态及涌浪的影响。由于淋溪河导流洞出口布置位置的特殊性,试验尝试了不同的布置方式及多种出口消能形式。试验结果表明:导流洞出口加设侧导墙可有效地阻止主流对导流洞出口水流的压迫,防止水流集中,有利于水流的扩散;加设消力墩可使水流横向、纵向、垂向得到充分的扩散,达到消能的目的,有效地减小水流对下游河道的冲刷,降低下游河道的流速及水位壅高高度。     

宽尾墩与消力墩在班多水电站的应用

结合班多水电站整体水工模型试验,提出了利用宽尾墩能够收缩水流、抬高闸室内水面的特点,改善了泄洪闸堰面上出现的负压;针对下游河床冲刷偏深的问题,通过在混凝土护坦上设置消力墩,极大地减轻了下游冲刷.试验推荐的修改体型已经被工程采用.     

基于迁钢连退机组工程浅谈对炉压控制系统D7档板的更改方案

本文基于迁钢连退机组工程,针对目前应用的炉压控制系统的D7档板在其构成和控制方式方面进行了分析和介绍,针对其存在的缺点,提出了能够代替该系统且满足工艺要求的新方案。     

Efficiency of operation of a T-250/300–240 turbine without moving blades of last stages of the low-pressure cylinder

The results of detailed computations performed for actual electric and heat loads, pressure in the condenser, and other operating parameters are used to consider the changes in the efficiency of operation of a T-250/300–240 turbine after the removal of moving blades of the last stages of the low-pressure cylinder. It is shown that the expediency of running the turbine with removed blades should be determined proceeding from the expected modes of operation of the cogeneration plant in question for the whole year. __________ Translated from élektricheskie Stantsii, No. 11, November 2005, pp. 47–52.     

旋流式泄洪洞的特点及其运行可靠性分析

旋流式泄洪洞和常规洞一样也存在空蚀敏感区(在起旋洞水流转向的升坎处)。为了防止发生空蚀，在溢流堰的一侧墙设掺气折流坎，产生旋涡气囊进入竖井，向升坎处补气，同时在起旋洞的进口设增压折流坎，缩短螺距，使旋转流经过升坎，在离心力的作用下消除负压。采用掺气和增压这两项技术措施，可大大提高旋流式泄洪洞的运行可靠度。     

NUMERICAL SIMULATION OF TURBULENT FLOW CHARACTERISTICS IN A CURVED PIPE WITH A BAFFLE

A numerical study on the characteristics of developing turbulent flow in a curved pipe with a baffle was carried out in body-fitted coordinates with the k-ε model turbulence. A curved duct of square cross-section was examined first, and the results agree very well with the experimental data. Then two kinds of pipes, a normal curved pipe and that with a baffle were studied. The computational results are presented and compared with each other to illustrate the changes of the flow after adding the baffle. The longitudinal velocity in the pipe with a baffle was characterized by outer velocity bigger than the inner one. The secondary flow was characterized by four-vortex structure with the intensity reduced, which results in the equability of the flow field of the cross-section compared with that without a baffle, and has much more significant meaning in engineering.