Research On Fluid-thermal Coupling Performance Of Mechanical Seal In Reactor Coolant Pump Based On OpenFOAM

Mechanical seal is the main component of reactor coolant pump.In order to provide theoretical basis for the design and optimization of the mechanical seal for the nuclear main pump,the seal performance of taper end face mechanical seal and wave-tilt-dam mechanical seal is studied.When the mechanical seal of the nuclear main pump is running,there will be a micron level liquid film in the gap of the sealing ring.The liquid film model of taper end face mechanical seal and wave-tilt-dam mechanism seal were established respectively.The control equation are Navier-Stokes equation that could accurately describe the flow field,the energy equation with viscous dissipation terms and continuity equation.Compile a unidirectional coupling Thermal-Fluid solver to calculate the pressure field and temperature field.The influence of the changes of the structural parameters of two kinds of mechanical seals on the sealing performance is studied.Obtain the change law of the sealing performance with the change of the structural parameters is obtained and analyze the influence of the change of the structure parameters on the temperature field in the liquid film.It is found that the temperature change in the liquid film caused by viscous shear heat is not negligible since the maximum temperature difference in the liquid film is calculated.Based on the unidirectional coupling of heat flow and considering the relation of viscosity-temperature,a coupling Fluid-Thermal solver and corresponding viscosity model were compiled.The effect of the relation of viscosity-temperature on the sealing performance of taper end face mechanical seal and wave-tilt-dam mechanical seal is discussed.The influence of the relation of viscosity-temperature on the relative change rate of the seal performance parameters is analyzed with the change of the structural parameters.It is found that the effect of the viscosity temperature effect on the sealing performance cannot be ignored.Comprehensive consideration of leakage control,sealing capacity and operational stability of mechanical seal,putting forward the range of optimum structural parameters of taper end face mechanical seal and wave-tilt-dam mechanical seal according to the influence of structural parameters on seal performance,and the change of seal performance under the relation of viscosity-temperature.