摘要
推导了开度不变、转速不变和出力不变、转速不变两种运行条件下水轮机水力阻抗计算公式,分析了这两种运行条件下机组水力阻抗的差异,指出在混流式水轮机运行范围内,在前者条件下机组水力阻抗大于0,在后者条件下机组水力阻抗小于0.通过理论分析和数值计算相结合的方法,研究了机组水力阻抗对水电站有压输水系统自激振动特性的影响.研究表明:机组水力阻抗的正负决定了系统衰减因子的正负及大小,对系统频率的奇偶性具有选择性.
Two calculation formulas of hydraulic impedance of hydraulic turbine are derived in this paper, based on the two unit operating conditions, the one is constant guide vane opening and constant unit speed; the other is constant unit output and constant unit speed. The difference between the hydraulic impedance of hydraulic turbine under the two unit operating conditions is discussed; it is indicated that in the operation region of Francis turbine, under the former condition, the hydraulic impedance of hydraulic tur- bine is positive; under the latter condition, the hydraulic impedance is negative. The influence of hydraulic impedance of hydraulic turbine on self-excited hydraulic vibration characteristics of pressurized conveyance system in hydropower station is studied through theoretical analysis and numerical calculation. The investigation shows that the positive or negative of the attenuation factors of system depends on the positive or negative of the hydraulic impedance of hydraulic turbine, and the parity of the frequencies of the system depends on the hydraulic impedance of hydraulic turbine, too.
出处
《武汉大学学报（工学版）》
CAS
CSCD
北大核心
2012年第2期177-181,共5页
Engineering Journal of Wuhan University
关键词
水力学
水力机械
水力阻抗
理论分析
水轮机
水力振动
hydraulics
hydraulic machinery
hydraulic impedance
theoretical analysis
hydraulic turbine hydraulic vibration
