不同喷嘴组合形式下冲击式水轮机飞逸特性研究  

Research on Runaway Characteristics of Pelton Turbine under Different Nozzle Combination Forms

作　　者：袁一芳 Jimenez Darwin 韩磊 李德友[1,2] 刘永新 覃大清 YUAN Yifang;Jimenez Darwin;HAN Lei;LI Deyou;LIU Yongxin;QIN Daqing(School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China;State Key Laboratory of Hydro-Power Equipment,Harbin 150040,China;Harbin Electric Machinery Company Limited,Harbin 150040,China)

机构地区：[1]哈尔滨工业大学能源科学与工程学院,哈尔滨150001 [2]水力发电设备国家重点实验室,哈尔滨150040 [3]哈尔滨电机厂有限责任公司,哈尔滨150040

出　　处：《大电机技术》2024年第5期96-104,共9页Large Electric Machine and Hydraulic Turbine

基　　金：国家重点研发计划资助(SQ2023YFB3408401);水力发电设备全国重点实验室开放基金(SKLHE-ORF-202104);国家自然科学基金面上项目(52476026)。

摘　　要：随着中国西南地区水力资源的进一步开发,冲击式水轮机已被进一步研究和使用。但是其在飞逸过程中,射流极不稳定,转轮转速会迅速增加,输出功率不可控,这会对冲击式水轮机造成损坏和安全运行风险。本研究应用计算流体动力学方法对六喷针冲击式水轮机的飞逸过程流动特性开展数值模拟研究,计算了包括六个喷针开度从6~30mm的7个工况和一个、三个喷嘴分别工作时的10个工况,进而获得了不同工况下的飞逸转速的变化规律。结果表明:当六个喷嘴处于工作状态时,飞逸转速为额定转轮速度的1.55倍,低于理论计算的1.936倍,并且飞逸转速随着喷针开度增大而均匀增加。在最优开度为18mm(行程等于1)的情况下,在三个喷嘴(1号、3号和5号)和一个喷嘴(1号)分别工作时飞逸转速是转轮速度的1.66倍和1.68倍。最后,确定了高速射流及二次流旋涡强度对飞逸转速的影响,六喷嘴条件下二次流引起高强度旋涡结构,且射流之间、射流与水斗之间存在干涉,使得水力损失增大,飞逸转速较小。单喷嘴和三喷嘴条件下旋涡强度较低,射流之间干涉很小或者没有干涉,飞逸转速较六喷嘴条件更高。With the further development of the hydropower in southwestern China,Pelton turbines have been further investigated and installed.However,during its runaway process,the water jet is extremely unstable,the runners revolution increases rapidly,and the output power is uncontrollable,which can cause damage and safety operation risks to the Pelton turbine.This study performed numerical simulation on the flow characteristics of the runaway process of a six nozzle Pelton turbine based on computational fluid dynamics.Seven operating conditions including six nozzle openings ranging from 6~30mm and 10 operating conditions with one and three nozzles operating separately were calculated,and the variation patterns of runaway speed under different operating conditions were obtained.The results show that when the six nozzles are in operation,the runaway speed is 1.55 times the rated runner speed,which is lower than the theoretical calculation of 1.936 times,and the runaway speed has an almost linear increasing trend with the nozzle opening.Under the optimal opening of 18mm(stroke equal to 1),the runaway speed is 1.66 times and 1.68 times the runner speed when three nozzles(#1,#3,and#5)and one nozzle(#1)are operating,respectively.Finally,the influence of high-speed jet and swirling strength of secondary flow on runaway speed was determined.Under the condition of six nozzles,secondary flow causes high-strength vortex,and there is interference between the jets and between the jets and buckets,resulting in increased hydraulic losses and lower runaway speeds.The swirling strength is lower under the conditions of one nozzle and three nozzles,and there is little or no interference between the jets.The runaway speeds are higher than the condition of six nozzles.

关 键 词：冲击式水轮机 飞逸转速 旋涡强度 水力损失 计算流体动力学 

分 类 号：TK735.1[交通运输工程—轮机工程]