自由液面对贯流式水轮机性能影响的数值研究
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摘要
贯流式水轮机已成为开发低水头和超低水头水力资源及潮汐能的良好机型,但振动、出力不足等问题频繁出现。同时贯流式机组水头与转轮直径之比(H/D1)较小,受比尺效应的影响,依靠模型机所得到的水轮机性能与实际存在差异。鉴于此,文章在考虑与不考虑库区自由液面及水流重力两种情况下对贯流式水轮机真机进行数值研究,对比分析自由液面及水流重力对水轮机性能的影响,并揭示贯流式水轮机内部真实流动状态以及出力不足的原因。研究结果表明:在自由液面及水流重力影响下,贯流式水轮机进口段水流呈现明显的不均匀性,转轮内压力分布由顶部到底部逐渐增大,叶片在旋转过程中要经历周期性的压力波动;不同位置的叶片对转轴产生的扭矩不同,水轮机的出力及效率有较大幅度的下降。研究结果将对贯流式水轮机的设计及运行具有一定的指导意义。
The bulb turbine has become a good model for developing low head or ultra-low head water resources and tidal energy, but the problems of vibration and insufficient output frequently occur. Certain differences exist between the performance of its prototype and that predicted by the model test, due to the scaling effects and the small ratio of water head to its runner diameter(H/D1). This paper presents numerical simulations of a prototype bulb turbine working under two conditions of considering and neglecting the effects of free surface and water gravity, focusing on analysis of the effects in terms of its running performance and the cause of its insufficient output through examining the details of its internal flows. The results show that under the effects of free surface and water gravity, the turbine features a poor uniformity of the flow around its inlet and a gradual pressure increasing from top to bottom, and consequently a blade undergoes periodic pressure fluctuations during its rotation. And the blades at different positions contribute different torques to the shaft and the power output and efficiency of the bulb turbine are decreased considerably.
The bulb turbine has become a good model for developing low head or ultra-low head water resources and tidal energy, but the problems of vibration and insufficient output frequently occur. Certain differences exist between the performance of its prototype and that predicted by the model test, due to the scaling effects and the small ratio of water head to its runner diameter(H/D1). This paper presents numerical simulations of a prototype bulb turbine working under two conditions of considering and neglecting the effects of free surface and water gravity, focusing on analysis of the effects in terms of its running performance and the cause of its insufficient output through examining the details of its internal flows. The results show that under the effects of free surface and water gravity, the turbine features a poor uniformity of the flow around its inlet and a gradual pressure increasing from top to bottom, and consequently a blade undergoes periodic pressure fluctuations during its rotation. And the blades at different positions contribute different torques to the shaft and the power output and efficiency of the bulb turbine are decreased considerably.
引文
[1]Neill S P,Litt E J,Couch S J,et al.The impact of tidal stream turbines on large-scale sediment dynamics[J].Renewable Energy,2009,34(12):2803-2812.
[2]Charlier R H,Fink C W.Ocean energy-Tide and tidal power[M].Springer,2009.
[3]张晓君,程振兴,张兆德.潮汐能利用的现状与浙江潮汐能的发展前景[J].中国造船,2010,51(S1):144-147.ZHANG Xiaojun,CHENG Zhenxing,ZHANG Zhaode.Present state of tidal energy utilization and perspectives of tidal energy in Zhejiang province[J].Shipbuilding of China,2010,51(S1):144-147.(in Chinese)
[4]张超,齐广平.白水江横丹水电站灯泡贯流式水轮机组运行振动成因分析与消减[J].农业科技与信息,2015(24):118-119.ZHANG Chao,QI Guangping.Cause analysis and elimination of operation vibration for bulb turbine unit of Hengdan Hydropower Station[J].Agricultural ScienceTechnology and Information,2015(24):118-119.(in Chinese)
[5]Necker J,Aschenbrenner T,Moser W.Cavitation in a bulb turbine[C].The 7th International Symposium on Cavitation CAV2009,Michigan,2009.
[6]许惠敏.灯泡贯流式水轮机导叶、桨叶协联变化的关系和消除振动方法[J].西北水电,2012(6):67-69.XU Huimin.Coherence variation relationship and vibration elimination methods between wicket gate and runner blade of bulb tubular turbine[J].Northwest Hydropower,2012(6):67-69.(in Chinese)
[7]张飞,陈俊锋,吕刚,等.灯泡贯流式水轮机出力提升方案研究[J].中国水利水电科学研究院学报,2016,14(3):219-223.ZHANG Fei,CHEN Junfeng,LV Gang,et al.Output power improvement research of bulb turbine[J].Journal of China Institute of Water Resources and Hydropower Research,2016,14(3):219-223.(in Chinese)
[8]刘忠,邹淑云,李建勇,等.灯泡贯流式水轮机出力不足原因分析与对策研究[J].电站系统工程,2014,30(6):73-76.LIU Zhong,ZOU Shuyun,LI Jianyong,et al.Reason analysis and countermeasures research for output deficiency of bulb turbines[J].Power System Engineering,2014,30(6):73-76.(in Chinese)
[9]陈南文.百龙滩水电厂灯泡贯流式水轮机转轮室空蚀处理[J].红水河,2015,34(4):58-61.CHEN Nanwen.Treatment of cavitation erosion in runner chamber of bulb tubular turbine in Bailongtan Hydropower Station[J].Hongshui River,2015,34(4):58-61.(in Chinese)
[10]赵亚萍,廖伟丽,李志华,等.C型及S型叶片的贯流式水轮机流场特性[J].农业工程学报,2013,29(17):47-53,294.ZHAO Yaping,LIAO Weili,LI Zhihua,et al.Flow field performance of bulb turbine with C-type or S-type blades[J].Transactions of the Chinese Society of Agricultural Engineering,2013,29(17):47-53,294.(in Chinese)
[11]李凤超,樊红刚,王正伟,等.贯流式水轮机桨叶涡动力学优化设计[J].清华大学学报(自然科学版),2011,51(6):836-839.LI Fengchao,FAN Honggang,WANG Zhengwei,et al.Optimum design of runner blades of a tubular turbine based on vorticity dynamic[J].Journal of Tsinghua University(Science and Technology),2011,51(6):836-839.(in Chinese)
[12]郑小波,翁凯,王玲军.叶片尾部形状对双向贯流式水轮机性能的影响[J].农业工程学报,2015,31(6):76-81.ZHENG Xiaobo,WENG Kai,WANG Lingjun.Effect of blade tail’s shape on hydraulic performance of bidirectional bulb turbine[J].Transactions of the Chinese Society of Agricultural Engineering,2015,31(6):76-81.(in Chinese)
[13]朱国俊,郭鹏程,罗兴锜,等.贯流式水轮机转轮叶片的多学科优化设计[J].农业工程学报,2014,30(2):47-55.ZHU Guojun,GUO Pengcheng,LUO Xingqi,et al.Optimal design of runner blade in bulb turbine base on multidisciplinary feasible method[J].Transactions of the Chinese Society of Agricultural Engineering,2014,30(2):47-55.(in Chinese)
[14]Li Y M,Song G Q,Yan Y L.Transient hydrodynamic analysis of the transition process of bulb hydraulic turbine[J].Advances in Engineering Software,2015,90(C):152-158.
[15]Duquesne P,Maciel Y,Deschênes C.Investigation of flow separation in a diffuser of a bulb turbine[J].Journal of Fluids Engineering,2016,138(1):1-9.
[16]田树堂.灯泡式水轮机运行性能的分析与评判[J].东方电机,1994(1):79-85.TIAN Shutang.Analysis and evaluation of operation performance of bulb turbine[J].Dongfang Electrical Machine,1994(1):79-85.(in Chinese)
[17]M Beni?ek,I Bo?i?,B Ignjatovi?.The comparative analysis of model and prototype test results of bulb turbine[C].25th IAHR Symposium on Hydraulic Machinery and Systems,2010,Romania.
[18]刘延泽,常近时.重力场对灯泡贯流式水轮机流场分析及水力性能评估的影响[J].水利学报,2008,39(1):96-102.LIU Yanze,CHANG Jinshi.Influence of gravity on flow field analysis and hydraulic performance evaluation of bulb turbine[J].Journal of Hydraulic Engineering,2008,39(1):96-102.(in Chinese)
[19]Zhao Y P,Liao W L,Feng H D,et al.Experimental and numerical study on inlet and outlet conditions of a bulb turbine with considering free surface[C].26th IAHR Symposium on Hydraulic Machinery and Systems,Beijing,2012.
[20]Zhao Y P,Liao W L,Li Z H,et al.Numerical study on the performance of bulb turbine by using runaway condition to flood discharge and sediment dredging[C].27th IAHR Symposium on Hydraulic Machinery and Systems,Montreal,2014.
[21]李玲,陈永灿,李永红.三维VOF模型及其在溢洪道水流计算中的应用[J].水力发电学报,2007,26(2):83-87.LI Ling,CHEN Yongcan,LI Yonghong.Three dimensional VOF model and its application to the water flow calculation in the spillway[J].Journal of Hydroelectric Engineering,2007,26(2):83-87.(in Chinese)
[2]Charlier R H,Fink C W.Ocean energy-Tide and tidal power[M].Springer,2009.
[3]张晓君,程振兴,张兆德.潮汐能利用的现状与浙江潮汐能的发展前景[J].中国造船,2010,51(S1):144-147.ZHANG Xiaojun,CHENG Zhenxing,ZHANG Zhaode.Present state of tidal energy utilization and perspectives of tidal energy in Zhejiang province[J].Shipbuilding of China,2010,51(S1):144-147.(in Chinese)
[4]张超,齐广平.白水江横丹水电站灯泡贯流式水轮机组运行振动成因分析与消减[J].农业科技与信息,2015(24):118-119.ZHANG Chao,QI Guangping.Cause analysis and elimination of operation vibration for bulb turbine unit of Hengdan Hydropower Station[J].Agricultural ScienceTechnology and Information,2015(24):118-119.(in Chinese)
[5]Necker J,Aschenbrenner T,Moser W.Cavitation in a bulb turbine[C].The 7th International Symposium on Cavitation CAV2009,Michigan,2009.
[6]许惠敏.灯泡贯流式水轮机导叶、桨叶协联变化的关系和消除振动方法[J].西北水电,2012(6):67-69.XU Huimin.Coherence variation relationship and vibration elimination methods between wicket gate and runner blade of bulb tubular turbine[J].Northwest Hydropower,2012(6):67-69.(in Chinese)
[7]张飞,陈俊锋,吕刚,等.灯泡贯流式水轮机出力提升方案研究[J].中国水利水电科学研究院学报,2016,14(3):219-223.ZHANG Fei,CHEN Junfeng,LV Gang,et al.Output power improvement research of bulb turbine[J].Journal of China Institute of Water Resources and Hydropower Research,2016,14(3):219-223.(in Chinese)
[8]刘忠,邹淑云,李建勇,等.灯泡贯流式水轮机出力不足原因分析与对策研究[J].电站系统工程,2014,30(6):73-76.LIU Zhong,ZOU Shuyun,LI Jianyong,et al.Reason analysis and countermeasures research for output deficiency of bulb turbines[J].Power System Engineering,2014,30(6):73-76.(in Chinese)
[9]陈南文.百龙滩水电厂灯泡贯流式水轮机转轮室空蚀处理[J].红水河,2015,34(4):58-61.CHEN Nanwen.Treatment of cavitation erosion in runner chamber of bulb tubular turbine in Bailongtan Hydropower Station[J].Hongshui River,2015,34(4):58-61.(in Chinese)
[10]赵亚萍,廖伟丽,李志华,等.C型及S型叶片的贯流式水轮机流场特性[J].农业工程学报,2013,29(17):47-53,294.ZHAO Yaping,LIAO Weili,LI Zhihua,et al.Flow field performance of bulb turbine with C-type or S-type blades[J].Transactions of the Chinese Society of Agricultural Engineering,2013,29(17):47-53,294.(in Chinese)
[11]李凤超,樊红刚,王正伟,等.贯流式水轮机桨叶涡动力学优化设计[J].清华大学学报(自然科学版),2011,51(6):836-839.LI Fengchao,FAN Honggang,WANG Zhengwei,et al.Optimum design of runner blades of a tubular turbine based on vorticity dynamic[J].Journal of Tsinghua University(Science and Technology),2011,51(6):836-839.(in Chinese)
[12]郑小波,翁凯,王玲军.叶片尾部形状对双向贯流式水轮机性能的影响[J].农业工程学报,2015,31(6):76-81.ZHENG Xiaobo,WENG Kai,WANG Lingjun.Effect of blade tail’s shape on hydraulic performance of bidirectional bulb turbine[J].Transactions of the Chinese Society of Agricultural Engineering,2015,31(6):76-81.(in Chinese)
[13]朱国俊,郭鹏程,罗兴锜,等.贯流式水轮机转轮叶片的多学科优化设计[J].农业工程学报,2014,30(2):47-55.ZHU Guojun,GUO Pengcheng,LUO Xingqi,et al.Optimal design of runner blade in bulb turbine base on multidisciplinary feasible method[J].Transactions of the Chinese Society of Agricultural Engineering,2014,30(2):47-55.(in Chinese)
[14]Li Y M,Song G Q,Yan Y L.Transient hydrodynamic analysis of the transition process of bulb hydraulic turbine[J].Advances in Engineering Software,2015,90(C):152-158.
[15]Duquesne P,Maciel Y,Deschênes C.Investigation of flow separation in a diffuser of a bulb turbine[J].Journal of Fluids Engineering,2016,138(1):1-9.
[16]田树堂.灯泡式水轮机运行性能的分析与评判[J].东方电机,1994(1):79-85.TIAN Shutang.Analysis and evaluation of operation performance of bulb turbine[J].Dongfang Electrical Machine,1994(1):79-85.(in Chinese)
[17]M Beni?ek,I Bo?i?,B Ignjatovi?.The comparative analysis of model and prototype test results of bulb turbine[C].25th IAHR Symposium on Hydraulic Machinery and Systems,2010,Romania.
[18]刘延泽,常近时.重力场对灯泡贯流式水轮机流场分析及水力性能评估的影响[J].水利学报,2008,39(1):96-102.LIU Yanze,CHANG Jinshi.Influence of gravity on flow field analysis and hydraulic performance evaluation of bulb turbine[J].Journal of Hydraulic Engineering,2008,39(1):96-102.(in Chinese)
[19]Zhao Y P,Liao W L,Feng H D,et al.Experimental and numerical study on inlet and outlet conditions of a bulb turbine with considering free surface[C].26th IAHR Symposium on Hydraulic Machinery and Systems,Beijing,2012.
[20]Zhao Y P,Liao W L,Li Z H,et al.Numerical study on the performance of bulb turbine by using runaway condition to flood discharge and sediment dredging[C].27th IAHR Symposium on Hydraulic Machinery and Systems,Montreal,2014.
[21]李玲,陈永灿,李永红.三维VOF模型及其在溢洪道水流计算中的应用[J].水力发电学报,2007,26(2):83-87.LI Ling,CHEN Yongcan,LI Yonghong.Three dimensional VOF model and its application to the water flow calculation in the spillway[J].Journal of Hydroelectric Engineering,2007,26(2):83-87.(in Chinese)