设有掺气分流墩的溢流表孔优化试验
|
摘要
针对高山峡谷地区建坝存在单宽流量大、消能范围小、布置困难等问题,结合亚碧罗水电站中的4个高低位溢流表孔,采用模型试验研究的方法,对建筑物的出口段挑流型式进行了整体优化,并对设有掺气分流墩的低位溢流表孔进行了试验。结果表明,高位表孔和低位表孔分别采用窄缝挑坎和掺气分流墩有效解决了消能区域集中的问题;低位表孔出口的四面体优化墩可保持挑射水流的连续且横向扩散充分;溢流表孔直线段设置的掺气设施运行良好;反弧段压力变化符合自由表面凹曲面上水流的压力分布规律,脉动压强的优势频率在0.033～0.201 Hz之间变化;反弧段局部部位的最小水流空化数为0.15,应从施工不平整度和运行方面加以控制。
For the dam construction in the high mountain gorge area, there are problems of layout difficulty, big unit discharge and small energy dissipation. Taking the hydropower station with 4 high and low spillway surface orifices as an example, the overall optimization of the flow pattern at the outlet section of the building and the hydraulic characteristics of the spillway surface orifice are carried out by the model tests. The results show that the problem of concentration of energy dissipation area is solved effectively by adopting narrow slot cantilever and aerated shunt pier respectively. The tetrahedron optimization pier at the outlet of the low surface outlet can maintain the continuous and horizontal diffusion of the jet flow. The air entraining facilities installed at the straight-line section of the overflow spillway is running well. The flip bucket pressure distribution is consistent with the pressure distribution on the free surface concave surface. The dominant frequency of fluctuating pressure varies from 0.033 to 0.201 Hz. The minimum number of cavitation in the reverse arc is 0.15. Therefore, it needs to be controlled in terms of construction irregularity and operation.
For the dam construction in the high mountain gorge area, there are problems of layout difficulty, big unit discharge and small energy dissipation. Taking the hydropower station with 4 high and low spillway surface orifices as an example, the overall optimization of the flow pattern at the outlet section of the building and the hydraulic characteristics of the spillway surface orifice are carried out by the model tests. The results show that the problem of concentration of energy dissipation area is solved effectively by adopting narrow slot cantilever and aerated shunt pier respectively. The tetrahedron optimization pier at the outlet of the low surface outlet can maintain the continuous and horizontal diffusion of the jet flow. The air entraining facilities installed at the straight-line section of the overflow spillway is running well. The flip bucket pressure distribution is consistent with the pressure distribution on the free surface concave surface. The dominant frequency of fluctuating pressure varies from 0.033 to 0.201 Hz. The minimum number of cavitation in the reverse arc is 0.15. Therefore, it needs to be controlled in terms of construction irregularity and operation.
引文
[1] 郭红民,陈昌仕,夏修宝,等.水石门水电站溢流表孔挑流消能数值模拟[J].水电能源科学,2015,33(4):109-112.
[2] 秦根泉,蒋水华.表孔溢流堰体型优化设计及模型试验验证[J].人民长江,2016,47(8):94-98.
[3] 张春满,刘沛清,刘宪亮.峡谷区高拱坝射流入射水垫塘冲击压力特性的试验研究[J].灌溉排水学报,2010,29(2):109-111.
[4] 魏柳,杨庆,戴光清,等.掺气挑坎通气量试验研究[J].工程科学与技术,2015,47(s1):18-23.
[5] 高学平,贾来飞,宋慧芳.溢洪道掺气坎槽后掺气水流三维数值模拟研究[J].水力发电学报,2014,33(2):90-96.
[6] 时启燧,潘水波,邵英英,等.通气减蚀挑坎水力学问题的试验研究[J].水利学报,1983(3):1-13.
[7] 王三一,陈霞林,李森.乌江渡水电站十年运行情况[J].水力发电学报,1994(4):12-24.
[8] 南军虎,李正安,乔明秋,等.高山峡谷大流量下溢流表孔体型试验[J].兰州理工大学学报,2011,37(6):42-46.
[9] DL5166-2002,溢洪道设计规范[S].
[10] 付倩,王冰伟.某水电站底孔泄水道冲蚀破坏原因分析及修补措施[J].中国水利水电科学研究院学报,2015,13(2):157-160.
[2] 秦根泉,蒋水华.表孔溢流堰体型优化设计及模型试验验证[J].人民长江,2016,47(8):94-98.
[3] 张春满,刘沛清,刘宪亮.峡谷区高拱坝射流入射水垫塘冲击压力特性的试验研究[J].灌溉排水学报,2010,29(2):109-111.
[4] 魏柳,杨庆,戴光清,等.掺气挑坎通气量试验研究[J].工程科学与技术,2015,47(s1):18-23.
[5] 高学平,贾来飞,宋慧芳.溢洪道掺气坎槽后掺气水流三维数值模拟研究[J].水力发电学报,2014,33(2):90-96.
[6] 时启燧,潘水波,邵英英,等.通气减蚀挑坎水力学问题的试验研究[J].水利学报,1983(3):1-13.
[7] 王三一,陈霞林,李森.乌江渡水电站十年运行情况[J].水力发电学报,1994(4):12-24.
[8] 南军虎,李正安,乔明秋,等.高山峡谷大流量下溢流表孔体型试验[J].兰州理工大学学报,2011,37(6):42-46.
[9] DL5166-2002,溢洪道设计规范[S].
[10] 付倩,王冰伟.某水电站底孔泄水道冲蚀破坏原因分析及修补措施[J].中国水利水电科学研究院学报,2015,13(2):157-160.