Introduction of nuclear power shaft seal factory owners

Reactor primary coolant pump ( hereinafter referred to as the main pump ) is the heart of the reactor . Water filling the primary system , the use of dynamic driven main pump gas, before the heap in the open , using the master pump loop temperature reached 280 ℃ open heap condition .
In normal operation, the reactor coolant from the reactor effluent flows through the main channel into the steam generator, the heat is transferred to the secondary circuit water , and then pumped back to the reactor by the main loop through the main pump motor with large flywheel to increase primary pump idle time , maintain proper inertia , ensuring power outage core fuel elements will not be burned.
Qinshan one of the two main pump is a vertical , single suction, Francis , by the end of the pump housing and safety , the rotor components, shaft barrier seals parts, bearing parts, oil system , seal water and cold water system components located . Unit Total height 9.5 m, the reactor coolant water from the bottom of the axial , radial discharge levels from the drive end pump counterclockwise rotation.
Main pump shaft seal is a mechanical seal , the use of three identical hydrodynamic seal in series, the graphite ring material , stationary ring material is tungsten carbide, other static sealing material is EPDM.
Three-stage seal the pressure drop of the system pressure by 40%, 40 %, 20% to allocate , but each system -level design to withstand full pressure . Sealing pressure drop values ​​are assigned at all levels rely on stream -flow device festive controlled leakage flow to achieve the first stage and second stage sealed throttling device composed by two coiled capillary tube , sealed throttling device is the third level rely on a restrictor to achieve.
In all conditions, the shaft truck seal working life of at least 10,000 hours .