X型叶片水轮机水力特点及全三维数值模拟

Hydraulic Characteristics and 3-D Numerical Simulation for Francis Turbine with X-type Blades

X型叶片为先进水轮机设备的关键部件,对其水力特性研究很有必要。以新疆某水利工程为例,在联合坐标系下对低水头大变幅X型叶片水轮机流动进行了CFD计算,得到了蜗壳、座环、活动导叶、转轮和尾水管等过流部件的压力分布和速度分布特性,计算结果表明,X型叶片水轮机在设计水头至最小水头大流量条件下更易发生空蚀破坏,而在最大水头小开度条件下尾水管脉动压力变幅较大,振动问题突出。

X-type blade is the key part of the advanced turbine and it is essential to research its hydraulic characteristics.Taking a certain hydraulic project in Xinjiang Province for an example,CFD calculation of the water flow through the Francis turbine with X-type blades is performed under the stationary coordinate system for the spring case,stationary ring and guide blade coupled with the rotational coordinate system for the turbine runner.The pressure and velocity distribution in the passage of spring case,stationary ring,guide blades,runner and draft tube are obtained.The results show that the turbine with X-type blades is easy to surfer from the cavitation erosion under large discharge from the design water head to minimum water head,and the pressure pulse amplitude in the draft tube is larger under maximum water head with small guide opening,which the vibration is stand out.