淹没射流与水平旋流梯级内消能工的水力特性
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摘要
为解决导流洞改建为单一内消能泄洪洞出现的空蚀问题,作用水头难以提高,运行方式和灵活性有限等工程实际问题,提出了一种新型"淹没射流与旋流梯级内消能工"。通过模型试验对其基本流态与水力特性进行量测和分析,结果表明:竖井水位是保证稳定运行的关键条件,当其高于射流尾水洞洞径的1.2倍后,各部分流态均趋于稳定;上游水位与下游水位均会影响竖井水位,其中上游水位影响更为显著;射流孔口和起旋器孔口的无量纲泄流量与其相对净作用水头均为线性增大关系;在射流段、水平旋流洞段与旋流阻塞扩散段,壁面压强沿程呈现出明显的分三段降低、各段稳定变化的特征。本文试验条件下,各段的最大压强水头差与总水头的比值分别为0.12、0.47和0.2,射流和旋流两级消能最大净作用水头占总水头的比例分别为0.13～0.15和0.59～0.80,最大孔口流速26.2 m/s,射流尾水和旋流扩散段的最大断面平均流速10.5 m/s,14.5 m/s,表明其具有良好的分级分段的消能特性,体型基本合理,但总作用水头尚有较大的提高余地,分级消能的比例尚需进一步优化。
This paper describes a new type of two-stage internal energy dissipators with submerged jet and horizontal swirl flow, aiming at cavitation erosion of the discharge tunnel with internal energy dissipators reconstructed from a diversion tunnel, practical engineering difficulties in increasing effective hydraulic head, and limitation on operation modes and flexibility. Basic flow patterns and hydraulic characteristics are measured and analyzed using scale model tests of tunnel dissipators of this type. The results show that the water level in the shaft is a decisive factor to ensure stable operation, and that the entire flow tends to be stable when this level is above 1.2 times the diameter of submerged-jet tunnel. It is affected by the water levels of the tunnel's inflow and tail flow, with a more significant effect of the former. In the sections of jet orifice and pipe cyclone orifice, the dimensionless flow rates are increased linearly with the increase in relative net effective heads; in the three sections of submerged jet, horizontal swirl flow and vortex diffusion, wall pressure shows a distinct three-stage drops and a stable variation along each section. Under the experimental conditions in this study, the ratios of pressure head drops in the three sections to the tunnel's working head are 0.12, 0.47 and 0.2 respectively, and the ratios of net effective heads of the two dissipators, i.e. the submerged-jet section and swirl flow section, are in the ranges of 0.13 to 0.15 and 0.59 to 0.80 respectively. And flow velocity around the two orifices is no higher than 26.2 m/s, and average flow velocities at the outlets of the jet section and vortex diffusion section are 10.5 m/s and 14.5 m/s respectively. All this shows that our design of the tunnel is good and reasonable in its two-stage energy dissipation and basic shapes, but much room is still left to improve the tunnel's working head and further optimize the allocation of dissipated energy to different stages.
This paper describes a new type of two-stage internal energy dissipators with submerged jet and horizontal swirl flow, aiming at cavitation erosion of the discharge tunnel with internal energy dissipators reconstructed from a diversion tunnel, practical engineering difficulties in increasing effective hydraulic head, and limitation on operation modes and flexibility. Basic flow patterns and hydraulic characteristics are measured and analyzed using scale model tests of tunnel dissipators of this type. The results show that the water level in the shaft is a decisive factor to ensure stable operation, and that the entire flow tends to be stable when this level is above 1.2 times the diameter of submerged-jet tunnel. It is affected by the water levels of the tunnel's inflow and tail flow, with a more significant effect of the former. In the sections of jet orifice and pipe cyclone orifice, the dimensionless flow rates are increased linearly with the increase in relative net effective heads; in the three sections of submerged jet, horizontal swirl flow and vortex diffusion, wall pressure shows a distinct three-stage drops and a stable variation along each section. Under the experimental conditions in this study, the ratios of pressure head drops in the three sections to the tunnel's working head are 0.12, 0.47 and 0.2 respectively, and the ratios of net effective heads of the two dissipators, i.e. the submerged-jet section and swirl flow section, are in the ranges of 0.13 to 0.15 and 0.59 to 0.80 respectively. And flow velocity around the two orifices is no higher than 26.2 m/s, and average flow velocities at the outlets of the jet section and vortex diffusion section are 10.5 m/s and 14.5 m/s respectively. All this shows that our design of the tunnel is good and reasonable in its two-stage energy dissipation and basic shapes, but much room is still left to improve the tunnel's working head and further optimize the allocation of dissipated energy to different stages.
引文
[1]谢省宗,吴一红,陈文学.我国高坝泄洪消能新技术的研究和创新[J].水利学报,2016,47(3):324-336.XIE Shengzong,WU Yihong,CHEN Wenxue.New technology and innovation on flood discharge and energy dissipation of high dams in China[J].Journal of Hydraulic Engineering,2016,47(3):324-336.(in Chinese)
[2]董兴林,郭军,杨开林,等.高水头大流量泄洪洞内消能工研究进展[J].中国水利水电科学研究院学报,2003,1(3):185-189.DONG Xinglin,GUO Jun,YANG Kailin,et al.Research and prospect of interior energy dissipaters in high head and large discharge tunnels[J].Journal of China Institute of Water Resources and Hydropower Research,2003,1(3):185-189.(in Chinese)
[3]李忠义,陈霞,陈美法.导流洞改建为孔板泄洪洞水力学问题研究[J].水利学报,1997,2(1):1-8.LI Zhongyi,CHEN Xia,CHEN Meifa.Study on hydraulic problems of spillway tunnels with orifices reformed from diversion tunnel[J].Journal of Hydraulic Engineering,1997,2(1):1-8.(in Chinese)
[4]余挺,田忠,王韦,等.收缩式洞塞泄洪洞的消能和空化特性[J].水利学报,2011,42(2):211-217.YU Ting,TIAN Zhong,WANG Wei,et al.Energy dissipation and cavitation characteristics of contracted plug in discharge tunnel[J].Journal of Hydraulic Engineering,2011,42(2):211-217.(in Chinese)
[5]尹则高,郑清鑫,王乐,等.渐缩渐扩洞塞消能和空化特性[J].水科学进展,2012,23(5):687-694.YIN Zhegao,ZHENG Qingxin,WANG Le,et al.Energy dissipater and cavitation characteristic study on gradual contraction and expansion discharge[J]Advances in Water Science,2012,23(5):687-694.(in Chinese)
[6]牛争鸣,安丰勇,余挺,等.旋流阻塞复合式泄洪洞的水力特性(2)[J].长江科学院院报,2008,23(4):5-8.NIU Zhengming,AN Fengyong,YU Ting,et al.Hydraulic characteristics of swirl tunnel with barrage(2)[J].Journal of Yangtze River Scientific Research Institute,2008,23(4):5-8.(in Chinese)
[7]董兴林,杨开林,王涛,等.公伯峡水电站旋流泄洪洞研究总结[J].水力发电,2008,34(1):75-78.DONG Xinglin,YANG Kailin,WANG Tao,et al.Review and summarization the swirling spillway tunnel in Gongboxia Hydropower Station[J].Water Power,2008,34(1):75-78.(in Chinese)
[8]巨江,卫勇,陈念水.公伯峡水电站水平旋流泄洪洞试验研究[J].水力发电学报,2004,23(5):88-91.JU Jiang,WEI Yong,CHEN Nianshui.Experiment study of horizontal vortex spillway tunnel in Gongboxia hydroelectric project[J].Journal of Hydroelectric Engineering,2004,23(5):88-91.(in Chinese)
[9]南军虎,牛争鸣,洪镝.公伯峡水平旋流泄洪洞水力特性研究[J].水力发电学报,2013,32(3):101-107.NAN Junhu,NIU Zhengming,HONG Di.Study on hydraulic in the characteristics of horizontal spiral flow Gongboxia discharge tunnel[J].Journal of Hydroelectric Engineering,2013,32(3):101-107.(in Chinese)
[10]牛争鸣,孙静,程庆迎.竖井进流水平旋转内消能泄水道流速分布与消能率的试验研究[J].水力发电学报,2003(1):61-69.NIU Zhengming,SUN Jing,CHENG Qingying.Experimental study on velocity distribution and energy dissipation ratio of the horizontal vortex and inner dissipating tunnel with an inlet shaft[J].Journal of Hydroelectric Engineering,2003(1):61-69.(in Chinese)
[11]牛争鸣,张鸣远,孙静.水平旋转内消能泄水道空腔环流的旋流特性[J].水力发电学报,2004,23(3):107-111.NIU Zhengming,ZHANG Mingyuan,SUN Jing.Swirl characteristic of level hollow swirling flow in inner dissipation discharge tunnel[J].Journal of Hydroelectric Engineering,2004,23(3):107-111.(in Chinese)
[12]牛争鸣,孙静,张鸣远.竖井进流水平旋转内消能泄水道的壁面压力分布规律[J].水力发电学报,2002(4):71-80.NIU Zhengming,SUN Jing,ZHANG Mingyuan.Wall pressure distribution of the horizontal vortex and inner enemy dissipating tunnel with a inlet shaft[J].Journal of Hydroelectric Engineering,2002(4):71-80.(in Chinese)
[13]Cao S L,Niu Z M,Yang J,et al.Velocity and pressure distributions in discharge tunnel of rotary obstruction composite inner energy dissipation[J].Science China Technological Sciences,2011,54(S1):111-117.
[14]牛争鸣,张鸣远.水平旋转内消能泄水道的流态序列、分区特性及临界条件[J].水动力学研究与进展(A辑),2005,20(1):14-18.NIU Zhengming,ZHANG Mingyuan.Basic flow pattern and critical hydraulic condition of rotary cavity flow in horizontal internal energy dissipation discharge tunnel with a shaft inlet[J].Journal of Hydrodynamics,Ser A,2005,20(1):14-18.(in Chinese)
[15]牛争鸣.竖井进流水平旋转内消能泄洪洞水动力学特性的研究与数值模拟[D].西安:西安交通大学,2006.NIU Zhengming.Research and numerical simulation of hydrodynamic characteristics of horizontal energy dissipation spillway tunnel with inlet-flow[D].Xi'an:Xi'an Jiaotong University,2006.(in Chinese)
[16]牛争鸣,孙静,张宗孝,等.水平旋转内消能泄洪洞空腔环流内气体压强的变化规律[J].水动力学研究与进展(A辑),2006,21(4):526-532.NIU Zhengming,SUN Jing,XIE Xiaoping,et al.Air pressure of level rotary flow in internal energy dissipation tunnel[J].Journal of Hydrodynamics,Ser A,2006,21(4):526-532.(in Chinese)
[17]刘善均,杨永全,许唯临,等.洞塞泄洪洞的水力特性研究[J].水利学报,2002(7):42-46.LIU Shanjun,YANG Yongquan,XU Weilin.Hydraulic characteristics of throat-type energy dissipater in discharge tunnels[J].Journal of Hydraulic Engineering,2002(7):42-46.(in Chinese)
[18]李建中,宁利中.高速水力学[M].西安:西北工业大学出版社,1994.LI Jianzhong,NING Lizhong.Hydraulics for highvelocity[M].Xi'an:Northwestern Polytechnical University Press,1994.(in Chinese)
[19]夏毓常.泄水建筑物若干体型初生空化数的合理取值[J].长江科学院院报,2000,17(2):6-9.XIA Yuchang.Rational determination of incipient cavitation numbers for some configurations in hydraulic structures[J].Journal of Yangtze River Scientific Research Institute,2000,17(2):6-9.(in Chinese)
[20]汪振,牛争鸣,李嘉.水平旋转内消能泄洪洞流速分布及紊动特性试验研究[J].水动力学研究与进展,2007,22(3):325-331.WANG Zhen,NIU Zhengming,LI Jia.Experimental study on velocity distribution and pulsation characteristic of inner dissipation discharge tunnel with level swirling flow[J].Journal of Hydrodynamics,2007,22(3):325-331.(in Chinese)
[21]孙静,牛争鸣,章晋雄.竖井进流水平旋转内消能泄水道流速分布的试验研究[J].水动力学研究与进展(A辑),2003,18(2):240-247SUN Jing,NIU Zhengming,ZHANG Jinxiong.Experimental study on velocity distribution of horizontal vortex and inner energy dissipating tunnel with inlet shaft[J].Journal of Hydrodynamic,Ser A,2003,18(2):240-247.(in Chinese)
[22]李奇龙.阻塞式水平旋流泄洪洞的水流水力特性研究[D].西安:西安理工大学,2015.LI Qilong.Study on hydraulic characteristics of flow in blocked horizontal swirling spillway[D].Xi'an:Xi'an University of Technology,2015.(in Chinese)
[23]安胜勋,王君利,陈念水,等.水平旋流消能泄洪洞设计与研究[M].北京:中国水利水电出版社,2008.AN Shengxun,WANG Junli,CHEN Nianshui,et al.Design and research of horizontal cyclone energy dissipation tunnel[M].Beijing:China Water Conservancy and Hydropower Press,2008.(in Chinese)
[2]董兴林,郭军,杨开林,等.高水头大流量泄洪洞内消能工研究进展[J].中国水利水电科学研究院学报,2003,1(3):185-189.DONG Xinglin,GUO Jun,YANG Kailin,et al.Research and prospect of interior energy dissipaters in high head and large discharge tunnels[J].Journal of China Institute of Water Resources and Hydropower Research,2003,1(3):185-189.(in Chinese)
[3]李忠义,陈霞,陈美法.导流洞改建为孔板泄洪洞水力学问题研究[J].水利学报,1997,2(1):1-8.LI Zhongyi,CHEN Xia,CHEN Meifa.Study on hydraulic problems of spillway tunnels with orifices reformed from diversion tunnel[J].Journal of Hydraulic Engineering,1997,2(1):1-8.(in Chinese)
[4]余挺,田忠,王韦,等.收缩式洞塞泄洪洞的消能和空化特性[J].水利学报,2011,42(2):211-217.YU Ting,TIAN Zhong,WANG Wei,et al.Energy dissipation and cavitation characteristics of contracted plug in discharge tunnel[J].Journal of Hydraulic Engineering,2011,42(2):211-217.(in Chinese)
[5]尹则高,郑清鑫,王乐,等.渐缩渐扩洞塞消能和空化特性[J].水科学进展,2012,23(5):687-694.YIN Zhegao,ZHENG Qingxin,WANG Le,et al.Energy dissipater and cavitation characteristic study on gradual contraction and expansion discharge[J]Advances in Water Science,2012,23(5):687-694.(in Chinese)
[6]牛争鸣,安丰勇,余挺,等.旋流阻塞复合式泄洪洞的水力特性(2)[J].长江科学院院报,2008,23(4):5-8.NIU Zhengming,AN Fengyong,YU Ting,et al.Hydraulic characteristics of swirl tunnel with barrage(2)[J].Journal of Yangtze River Scientific Research Institute,2008,23(4):5-8.(in Chinese)
[7]董兴林,杨开林,王涛,等.公伯峡水电站旋流泄洪洞研究总结[J].水力发电,2008,34(1):75-78.DONG Xinglin,YANG Kailin,WANG Tao,et al.Review and summarization the swirling spillway tunnel in Gongboxia Hydropower Station[J].Water Power,2008,34(1):75-78.(in Chinese)
[8]巨江,卫勇,陈念水.公伯峡水电站水平旋流泄洪洞试验研究[J].水力发电学报,2004,23(5):88-91.JU Jiang,WEI Yong,CHEN Nianshui.Experiment study of horizontal vortex spillway tunnel in Gongboxia hydroelectric project[J].Journal of Hydroelectric Engineering,2004,23(5):88-91.(in Chinese)
[9]南军虎,牛争鸣,洪镝.公伯峡水平旋流泄洪洞水力特性研究[J].水力发电学报,2013,32(3):101-107.NAN Junhu,NIU Zhengming,HONG Di.Study on hydraulic in the characteristics of horizontal spiral flow Gongboxia discharge tunnel[J].Journal of Hydroelectric Engineering,2013,32(3):101-107.(in Chinese)
[10]牛争鸣,孙静,程庆迎.竖井进流水平旋转内消能泄水道流速分布与消能率的试验研究[J].水力发电学报,2003(1):61-69.NIU Zhengming,SUN Jing,CHENG Qingying.Experimental study on velocity distribution and energy dissipation ratio of the horizontal vortex and inner dissipating tunnel with an inlet shaft[J].Journal of Hydroelectric Engineering,2003(1):61-69.(in Chinese)
[11]牛争鸣,张鸣远,孙静.水平旋转内消能泄水道空腔环流的旋流特性[J].水力发电学报,2004,23(3):107-111.NIU Zhengming,ZHANG Mingyuan,SUN Jing.Swirl characteristic of level hollow swirling flow in inner dissipation discharge tunnel[J].Journal of Hydroelectric Engineering,2004,23(3):107-111.(in Chinese)
[12]牛争鸣,孙静,张鸣远.竖井进流水平旋转内消能泄水道的壁面压力分布规律[J].水力发电学报,2002(4):71-80.NIU Zhengming,SUN Jing,ZHANG Mingyuan.Wall pressure distribution of the horizontal vortex and inner enemy dissipating tunnel with a inlet shaft[J].Journal of Hydroelectric Engineering,2002(4):71-80.(in Chinese)
[13]Cao S L,Niu Z M,Yang J,et al.Velocity and pressure distributions in discharge tunnel of rotary obstruction composite inner energy dissipation[J].Science China Technological Sciences,2011,54(S1):111-117.
[14]牛争鸣,张鸣远.水平旋转内消能泄水道的流态序列、分区特性及临界条件[J].水动力学研究与进展(A辑),2005,20(1):14-18.NIU Zhengming,ZHANG Mingyuan.Basic flow pattern and critical hydraulic condition of rotary cavity flow in horizontal internal energy dissipation discharge tunnel with a shaft inlet[J].Journal of Hydrodynamics,Ser A,2005,20(1):14-18.(in Chinese)
[15]牛争鸣.竖井进流水平旋转内消能泄洪洞水动力学特性的研究与数值模拟[D].西安:西安交通大学,2006.NIU Zhengming.Research and numerical simulation of hydrodynamic characteristics of horizontal energy dissipation spillway tunnel with inlet-flow[D].Xi'an:Xi'an Jiaotong University,2006.(in Chinese)
[16]牛争鸣,孙静,张宗孝,等.水平旋转内消能泄洪洞空腔环流内气体压强的变化规律[J].水动力学研究与进展(A辑),2006,21(4):526-532.NIU Zhengming,SUN Jing,XIE Xiaoping,et al.Air pressure of level rotary flow in internal energy dissipation tunnel[J].Journal of Hydrodynamics,Ser A,2006,21(4):526-532.(in Chinese)
[17]刘善均,杨永全,许唯临,等.洞塞泄洪洞的水力特性研究[J].水利学报,2002(7):42-46.LIU Shanjun,YANG Yongquan,XU Weilin.Hydraulic characteristics of throat-type energy dissipater in discharge tunnels[J].Journal of Hydraulic Engineering,2002(7):42-46.(in Chinese)
[18]李建中,宁利中.高速水力学[M].西安:西北工业大学出版社,1994.LI Jianzhong,NING Lizhong.Hydraulics for highvelocity[M].Xi'an:Northwestern Polytechnical University Press,1994.(in Chinese)
[19]夏毓常.泄水建筑物若干体型初生空化数的合理取值[J].长江科学院院报,2000,17(2):6-9.XIA Yuchang.Rational determination of incipient cavitation numbers for some configurations in hydraulic structures[J].Journal of Yangtze River Scientific Research Institute,2000,17(2):6-9.(in Chinese)
[20]汪振,牛争鸣,李嘉.水平旋转内消能泄洪洞流速分布及紊动特性试验研究[J].水动力学研究与进展,2007,22(3):325-331.WANG Zhen,NIU Zhengming,LI Jia.Experimental study on velocity distribution and pulsation characteristic of inner dissipation discharge tunnel with level swirling flow[J].Journal of Hydrodynamics,2007,22(3):325-331.(in Chinese)
[21]孙静,牛争鸣,章晋雄.竖井进流水平旋转内消能泄水道流速分布的试验研究[J].水动力学研究与进展(A辑),2003,18(2):240-247SUN Jing,NIU Zhengming,ZHANG Jinxiong.Experimental study on velocity distribution of horizontal vortex and inner energy dissipating tunnel with inlet shaft[J].Journal of Hydrodynamic,Ser A,2003,18(2):240-247.(in Chinese)
[22]李奇龙.阻塞式水平旋流泄洪洞的水流水力特性研究[D].西安:西安理工大学,2015.LI Qilong.Study on hydraulic characteristics of flow in blocked horizontal swirling spillway[D].Xi'an:Xi'an University of Technology,2015.(in Chinese)
[23]安胜勋,王君利,陈念水,等.水平旋流消能泄洪洞设计与研究[M].北京:中国水利水电出版社,2008.AN Shengxun,WANG Junli,CHEN Nianshui,et al.Design and research of horizontal cyclone energy dissipation tunnel[M].Beijing:China Water Conservancy and Hydropower Press,2008.(in Chinese)