Technical exchange on the role of water turbine air supplement

Water turbine air supplement is often used in conventional units, and it is of great significance to the operation of the unit. The water turbine air supplement device is one of the common and effective equipment for the unit.

When the Francis water turbine deviates from the optimal operating conditions (generally at 40% to 60% of the rated load), the tangential velocity of the water flow at the runner outlet increases, and the circulation in the water flow makes the center of the draft tube produce low pressure and form a vortex This vortex oscillates in a spiral shape and causes pressure pulsation in the draft tube. The tail water turbine vortex usually causes the vibration of the components of the unit, the swing of the shaft system, the pressure pulsation in the volute and the diversion steel pipe, and the fluctuation of the load. The primary purpose of turbine air supplement is to supplement air into the draft cone to weaken the vortex vacuum and reduce the strength of the vortex under the above working conditions, thereby absorbing vibration and improving the operating state.