Wafer butterfly valves is one of the large hydropower plants plant valve components and more widespread application, which is composed of a valve body, a butterfly plate and a control mechanism, set in the turbine spiral case inlet, in order to control the unit flow, its main role is to:
When a system failure, failure caused by over speed can be closed when the wafer butterfly valves to protect unit;
Close the wafer butterfly valves in order to downtime in the maintenance required;
Machine leader time phasing operation or long time shutdown standby, the system allows the case to close wafer butterfly valves in order to reduce Water Leakage guide vane.
Wafer butterfly valves is fully open or fully closed state during normal operation, the phenomenon of self closing operation in the wafer butterfly valves in the unit with the load conditions is called red. If the butterfly plate appeared in the operation slow deviate from the fully open state, rotating 30~70 degrees, so that wafer butterfly valves is part of the state, called a partial red.
Effect of hydro generating unit and harm of wafer butterfly valves is the main part of thought: caused by mechanical hydraulic turbine vibration; high speed flow will produce cavitation region in the butterfly board behind, so the disc subjected to cavitation damage; produce mechanical BIE Jin, the servomotor cylinder vibration, serious when broken connection screw; reduce the unit output.
Therefore, the discussion and solution of these problems is of great realistic significance to the operation safety of hydropower plant.
Post time: Dec-21-2018