喷嘴射流径向偏移斗叶对冲击式水轮机稳定性的影响  

Effect of radial offset bucket blades of nozzle jet on stability of Pelton turbines

作　　者：卿启维 邓方雄 李文斌 邓慧铭 余志顺[2] 卢加兴 刘小兵[2] QING Qiwei;DENG Fangxiong;LI Wenbin;DENG Huiming;YU Zhishun;LU Jiaxing;LIU Xiaobing(CHN Energy Dadu River Geshizha Hydropower Development Co.,Ltd.,Danba,Sichuan 626300,China;Key Laboratory of Fluid and Power Machinery,Ministry of Education,Xihua University,Chengdu,Sichuan 610039,China)

机构地区：[1]国能大渡河革什扎水电开发有限责任公司,四川丹巴626300 [2]西华大学流体及动力机械教育部重点实验室,四川成都610039

出　　处：《排灌机械工程学报》2023年第12期1283-1289,1296,共8页Journal of Drainage and Irrigation Machinery Engineering

基　　金：四川省水电能源创新能力建设项目(2022-510124-04-01-622476);国家自然科学基金资助项目(52009115)。

摘　　要：针对冲击式水轮机在实际安装和检修过程中,常出现喷嘴射流中心线偏移转轮斗叶节圆的问题,采用VOF多相流模型和SST k-ω湍流模型,对国电大渡河吉牛水电站冲击式水轮机斗叶内部压力脉动及转轮受力进行了数值模拟,并对射流偏移前后水轮机振摆和效率进行了实测,分析了喷嘴射流中心线径向偏移斗叶节圆对冲击式水轮机稳定性的影响.数据模拟时,水轮机设定3种运行工况:喷嘴射流中心线向转轮斗叶外缘方向偏移、向转轮中心方向偏移,以及无偏移.结果表明射流发生径向偏移后,水轮机轴向力和压力脉动显著增大,而径向力和效率均减小,并且向斗叶外缘方向偏移的压力脉动均大于向转轮中心方向偏移的,更大于无偏移工况的.根据数值模拟结果可得,轴向力最大时达到无偏移工况时的2.27倍;实测结果为向斗叶外缘方向偏移后的轴向振动较无偏移工况的高达3.40倍、径向摆度达到1.30倍.Aiming at the problem that the nozzle jet centerline is often offset from the runner bucket blade pitch circle during the actual installation and maintenance of the Pelton hydraulic turbine,VOF multiphase flow model and SST k-ω turbulence model were used to numerically simulate and analyze the pressure pulsation and runner force inside the bucket blade of the Pelton hydraulic turbine of Guodian Dadu River Jiniu Hydropower Station,after which the hydraulic turbine oscillation,stress on the runners and efficiency were measured before and after the jet offset,and the effect of the radial offset of the nozzle jet centerline from the bucket pitch circle on the stability of the Pelton turbine was analyzed.During data simulation,the turbine was set to operate under three conditions as follows:nozzle jet centerline offset toward the outer edge of the runner bucket blade,offset toward the runner center,and no offset condition.The results show that the radial offset of the jet causes a significant increase in the axial force and pressure pulsation of the turbine,while the radial force and efficiency are reduced,and the pressure pulsation of the offset to the outer edge of the bucket blade is greater than that of the offset to the center of the runner,and even greater than that of the non-offset condition.According to the numerical simulation results,the maximum axial force reaches 2.27 times of the non-offset condition,the measured axial vibration is 3.40 times higher and the radial oscillation is 1.30 times higher than that of the non-offset condition after shifting to the outer edge of the bucket blade.

关 键 词：冲击式水轮机 射流径向偏移斗叶 转轮受力 压力脉动 稳定性 数值模拟 吉牛水电站 

分 类 号：TK735.1[交通运输工程—轮机工程] S277.9[动力工程及工程热物理—流体机械及工程]