Mechanism Analysis And Experimental Study On Combined Coning And Waviness Mechanical Face Seal For Nuclear Reactor Coolant Pump

The mechanism and performance of one kind of mechanical face seal withcircumferential waviness and radially convergent gap used in reactor coolant pump innuclear power station is studied. In normal working condition, complete fluid film canbe formed between the seal rings, and the leakage rate through the gap is strictlycontrolled within a certain range in order to provide an efficient cooling effecton thefriction pair.A finite element model is developed to analysis the seal mechanism andperformance.The influence of sealing surface structure parameters on sealingperformance under a given closing force is also discussed. A new dimensionlessparameter “ratio of waviness to coning” is definedtodiscuss hydrostatic andhydrodynamic mechanism of the sealseparately. The analysis results show that itworks on hydrostatic effect under normal working condition while on hydrodynamiceffect under abnormal working condition, such as small clearance or lowerpressure.These results will be helpful to design this kind of mechanical seals inreactor coolant pump.An analysis methodof fluid-solid coupling is presented, which allows automaticiterative between the pressure distribution and the seal component deformation. Itgives a differentresult by using coupling method from that by hydrodynamic modelonly.A downsizing non-contact mechanical seal test rig is designed and manufacturedindependently. Furthermore, a series of sensing elements is selected and calibrated.Several tests are designed to verify the mechanism of combined coning and wavinessmechanical face seal.