泵站用轴流泵鱼友好型设计及鱼类存活率预测
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摘要
传统泵站使用中存在大量鱼类死亡现象.为了提高鱼类流经泵站流道后的存活率,采用与试验值吻合度较高的叶片撞击模型,预测了原型泵不同工况下的鱼类死亡率:理论上设计流量点鱼类死亡率高达68%.基于叶片撞击数学模型,提出了提高鱼类存活率的鱼友好型设计方法,分析了各鱼友好型设计对提高鱼类存活率的效果,其中叶片数和转速是影响撞击概率的主要因素,而叶片数是导致扬程变化灵敏度较低的因素;前缘弯掠大幅降低了垂直前缘的撞击速度分量,是影响撞击死亡率的主要因素,加厚型线头部是影响撞击死亡率的次要因素,但两者会加剧径向流动,降低叶片效率及汽蚀性能.经鱼友好型设计后,鱼类死亡率整体控制在30%以下,设计工况点下的鱼类死亡率由68%降低至13%,效果显著.该研究可为鱼友好型泵及泵站的开发应用提供参考.
A large number of fish suffer from injury and mortality when passing through a traditionally designed pumping station. In order to improve the survival rate when fish passing through the flow channels in a pumping station,fish mortality rates are predicted under various operational conditions in a conventional axial-flow pump by using a blade strike model which is with a better accuracy against experimental data. It is shown that the fish mortality rate at the design point is up to 68% theoretically in that pump. Based on this model,a fish-friendly hydraulic design approach is proposed for an axialflow pump to have better fish survival rate,and effects of a few design parameters on the rate are analyzed. It is turned out that number of blades and rotational speed are two major factors influencing blade strike probability. Because the pump head is almost twice sensitive to the rotational speed than to the number of blades,the impeller is kept having two blades to reduce the blade strike probability forfish. The chord length of blade is increased to cope with the head drop caused by reduced number of blades. To limit the axial length of pump,the increased proportion of chord length is a little bit small.The forward swept and extended leading edge can reduce strike velocity,i. e. the velocity component perpendicular to the leading edge,significantly,thus the leading edge is the primary factor affecting strike mortality rate,while the thickened leading edge is the secondary factor for the rate. However,these two factors can induce a stronger radial velocity component,causing a low hydraulic efficiency and poor cavitation performance. The fish mortality rate is all below 30% at any operating points,and the rate has been declined to 13% from initially 68% at the design point as fish passing through the fish-friendly pump,thus fish survival is remarkable. This study can provide a reference for development of fish-friendly axial-flow pump and its application in pumping stations.
A large number of fish suffer from injury and mortality when passing through a traditionally designed pumping station. In order to improve the survival rate when fish passing through the flow channels in a pumping station,fish mortality rates are predicted under various operational conditions in a conventional axial-flow pump by using a blade strike model which is with a better accuracy against experimental data. It is shown that the fish mortality rate at the design point is up to 68% theoretically in that pump. Based on this model,a fish-friendly hydraulic design approach is proposed for an axialflow pump to have better fish survival rate,and effects of a few design parameters on the rate are analyzed. It is turned out that number of blades and rotational speed are two major factors influencing blade strike probability. Because the pump head is almost twice sensitive to the rotational speed than to the number of blades,the impeller is kept having two blades to reduce the blade strike probability forfish. The chord length of blade is increased to cope with the head drop caused by reduced number of blades. To limit the axial length of pump,the increased proportion of chord length is a little bit small.The forward swept and extended leading edge can reduce strike velocity,i. e. the velocity component perpendicular to the leading edge,significantly,thus the leading edge is the primary factor affecting strike mortality rate,while the thickened leading edge is the secondary factor for the rate. However,these two factors can induce a stronger radial velocity component,causing a low hydraulic efficiency and poor cavitation performance. The fish mortality rate is all below 30% at any operating points,and the rate has been declined to 13% from initially 68% at the design point as fish passing through the fish-friendly pump,thus fish survival is remarkable. This study can provide a reference for development of fish-friendly axial-flow pump and its application in pumping stations.
引文
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[4]CADA G F,COUTANT C C,WHITENY R R.Development of biological criteria for the design of advanced hydropower turbines[R].Springfield,USA:US Dept.of Energy Idaho Operations Office,1997.
[5]DENG Zhiqun,CARLSON T J,PLOSKEY G R,et al.Evaluation of blade-strike models for estimating the biological performance of Kaplan turbines[J].Ecological modelling,2007,208(2/3/4):165-176.
[6]DENG Zhiqun,CARLSON T J,DAUBLE D D,et al.Fish passage assessment of an advanced hydropower turbine and conventional turbine using blade-strike modeling[J].Energies,2011,4(1):57-67.
[7]FERGUSON J W,PLOSKEY G R,LEONARDSSON K,et al.Combining turbine blade-strike and life cycle models to assess mitigation strategies for fish passing dams[J].Canadian journal of fisheries and aquatic sciences,2008,65(8):1568-1585.
[8]PLOSKEY G R,CARLSON T J.Comparison of bladestrike modeling results with empirical data[R].Richland,USA:Pacific Northwest National Laboratory,2004.
[9]DENG Z,CARLSON T J,PLOSKEY G R,et al.Evaluation of blade-strike models for estimating the biological performance of Large Kaplan Hydro Turbines[R].Richland,USA:Pacific Northwest National Laboratory,2005.
[10]VAN ESCH B P M.Fish injury and mortality during passage through pumping stations[J].Journal of fluids engineering,2012,134(7):1-9.
[11]CHENG Li,VAN ESCH B P M.Blade interaction forces in a mixed-flow pump with vaned diffuser[C]//Proceedings of the ASME 2009 Fluids Engineering Division Summer Meeting.Vail,USA:ASME,2009:165-173.
[12]VAN ESCH B,CHENG Li.Unstable operation of a mixed-flow pump and the influence of tip clearance[C]//Proceedings of the ASME-JSME-KSME 2011Joint Fluids Engineering Conference.Vail,USA:ASME,2011:79-87.
[13]VAN ESCH B P M,SPIERTS I L Y.Validation of a model to predict fish passage mortality in pumping stations[J].Canadian journal of fisheries and aquatic sciences,2014,71(12):1910-1923.
[14]AMARAL S V,HECKER G E,DIXON D A.Designing leading edges of turbine blades to increase fish survival from blade strike[R].Palo Alto,USA:Electric Power Research Institute,2011.
[15]KRAKERS L A,KRUYT N P,RUTJES H A.Fullscale validation of a comprehensive criterion to predict fish-friendliness of pumps[C]//Proceedings of ASME/JSME/KSME 2015 Joint Fluids Engineering Conference.Vail,USA:ASME,2015:1344-1357.
[16]潘强,张德胜,施卫东.基于叶片撞击模型的鱼友好型轴流泵优化设计[J].农业机械学报,2015,46(12):102-108.PAN Qiang,ZHANG Desheng,SHI Weidong.Optimization design of fish-friendly axial-flow pump based on blade strike model[J].Transactions of the CSAM,2015,46(12):102-108.(in Chinese)
[17]潘强,施卫东,张德胜.鱼友好型轴流泵流场数值分析及汽蚀性能优化[J].农业机械学报,2016,47(4):15-21.PAN Qiang,SHI Weidong,ZHANG Desheng.Numerical analysis of flow field and cativation performance optimization of fish-friendly axial-flow pump[J].Transactions of the CSAM,2016,47(4):15-21.(in Chinese)
[18]鄢碧鹏,汤方平.叶片数变化对轴流泵性能影响的研究[J].扬州大学学报(自然科学版),1998,1(3):53-55.YAN Bipeng,TANG Fangping.Study on the performance of axial-flow pump by changing the number of its blandes[J].Journal of Yangzhou University(natural science edition),1998,1(3):53-55.(in Chinese)
[19]SHI Weidong,ZHANG Desheng,GUAN Xingfan,et al.Numerical and experimental investigation on high-efficiency axial-flow pump[J].Chinese journal of mechanical engineering,2010,23(1):38-44.
[20]程成,施卫东,张德胜,等.后掠式双叶片污水泵固液两相流动规律的数值模拟[J].排灌机械工程学报,2015,33(2):116-122.CHENG Cheng,SHI Weidong,ZHANG Desheng,et al.Numerical simulation of solid-liquid two-phase turbulent flow of swept-back double blades sewage pump[J].Journal of drainage and irrigation machinery engineering,2015,33(2):116-122.(in Chinese)
[21]金实斌,曹璞钰,王洋.非均匀进流下喷水推进泵进流速度场的数值分析[J].排灌机械工程学报,2016,34(2):115-121.JIN Shibin,CAO Puyu,WANG Yang.Numerical ana-lysis on velocity field of water-jet pump under non-uniform inflow[J].Journal of drainage and irrigation machinery engineering,2016,34(2):115-121.(in Chinese)
[2]NEITZEL D A,RICHMOND M C,DAUBLE D D,et al.Laboratory studies on the effects of shear on fish:final report 2000[R].Springfield,USA:US Dept.of Energy Idaho Operations Office,2000.
[3]HOGAN J.The effects of high vacuum on fish[J].Transactions of the American Fisheries Society,1941,70(1):469-474.
[4]CADA G F,COUTANT C C,WHITENY R R.Development of biological criteria for the design of advanced hydropower turbines[R].Springfield,USA:US Dept.of Energy Idaho Operations Office,1997.
[5]DENG Zhiqun,CARLSON T J,PLOSKEY G R,et al.Evaluation of blade-strike models for estimating the biological performance of Kaplan turbines[J].Ecological modelling,2007,208(2/3/4):165-176.
[6]DENG Zhiqun,CARLSON T J,DAUBLE D D,et al.Fish passage assessment of an advanced hydropower turbine and conventional turbine using blade-strike modeling[J].Energies,2011,4(1):57-67.
[7]FERGUSON J W,PLOSKEY G R,LEONARDSSON K,et al.Combining turbine blade-strike and life cycle models to assess mitigation strategies for fish passing dams[J].Canadian journal of fisheries and aquatic sciences,2008,65(8):1568-1585.
[8]PLOSKEY G R,CARLSON T J.Comparison of bladestrike modeling results with empirical data[R].Richland,USA:Pacific Northwest National Laboratory,2004.
[9]DENG Z,CARLSON T J,PLOSKEY G R,et al.Evaluation of blade-strike models for estimating the biological performance of Large Kaplan Hydro Turbines[R].Richland,USA:Pacific Northwest National Laboratory,2005.
[10]VAN ESCH B P M.Fish injury and mortality during passage through pumping stations[J].Journal of fluids engineering,2012,134(7):1-9.
[11]CHENG Li,VAN ESCH B P M.Blade interaction forces in a mixed-flow pump with vaned diffuser[C]//Proceedings of the ASME 2009 Fluids Engineering Division Summer Meeting.Vail,USA:ASME,2009:165-173.
[12]VAN ESCH B,CHENG Li.Unstable operation of a mixed-flow pump and the influence of tip clearance[C]//Proceedings of the ASME-JSME-KSME 2011Joint Fluids Engineering Conference.Vail,USA:ASME,2011:79-87.
[13]VAN ESCH B P M,SPIERTS I L Y.Validation of a model to predict fish passage mortality in pumping stations[J].Canadian journal of fisheries and aquatic sciences,2014,71(12):1910-1923.
[14]AMARAL S V,HECKER G E,DIXON D A.Designing leading edges of turbine blades to increase fish survival from blade strike[R].Palo Alto,USA:Electric Power Research Institute,2011.
[15]KRAKERS L A,KRUYT N P,RUTJES H A.Fullscale validation of a comprehensive criterion to predict fish-friendliness of pumps[C]//Proceedings of ASME/JSME/KSME 2015 Joint Fluids Engineering Conference.Vail,USA:ASME,2015:1344-1357.
[16]潘强,张德胜,施卫东.基于叶片撞击模型的鱼友好型轴流泵优化设计[J].农业机械学报,2015,46(12):102-108.PAN Qiang,ZHANG Desheng,SHI Weidong.Optimization design of fish-friendly axial-flow pump based on blade strike model[J].Transactions of the CSAM,2015,46(12):102-108.(in Chinese)
[17]潘强,施卫东,张德胜.鱼友好型轴流泵流场数值分析及汽蚀性能优化[J].农业机械学报,2016,47(4):15-21.PAN Qiang,SHI Weidong,ZHANG Desheng.Numerical analysis of flow field and cativation performance optimization of fish-friendly axial-flow pump[J].Transactions of the CSAM,2016,47(4):15-21.(in Chinese)
[18]鄢碧鹏,汤方平.叶片数变化对轴流泵性能影响的研究[J].扬州大学学报(自然科学版),1998,1(3):53-55.YAN Bipeng,TANG Fangping.Study on the performance of axial-flow pump by changing the number of its blandes[J].Journal of Yangzhou University(natural science edition),1998,1(3):53-55.(in Chinese)
[19]SHI Weidong,ZHANG Desheng,GUAN Xingfan,et al.Numerical and experimental investigation on high-efficiency axial-flow pump[J].Chinese journal of mechanical engineering,2010,23(1):38-44.
[20]程成,施卫东,张德胜,等.后掠式双叶片污水泵固液两相流动规律的数值模拟[J].排灌机械工程学报,2015,33(2):116-122.CHENG Cheng,SHI Weidong,ZHANG Desheng,et al.Numerical simulation of solid-liquid two-phase turbulent flow of swept-back double blades sewage pump[J].Journal of drainage and irrigation machinery engineering,2015,33(2):116-122.(in Chinese)
[21]金实斌,曹璞钰,王洋.非均匀进流下喷水推进泵进流速度场的数值分析[J].排灌机械工程学报,2016,34(2):115-121.JIN Shibin,CAO Puyu,WANG Yang.Numerical ana-lysis on velocity field of water-jet pump under non-uniform inflow[J].Journal of drainage and irrigation machinery engineering,2016,34(2):115-121.(in Chinese)