Analysis Of Fluid-Structure Coupling Of Upstream Pumping Mechanical Seal With Inclined Groove

Mechanical seal is a shaft seal device that prevents fluid leakage and ensures safe and stable operation of the machine.With the continuous progress and development of mechanical seal technology,a new type of fluid dynamic pressure mechanical seal-upstream pumping mechanical seal has appeared.Upstream pumping mechanical seal is a typical representative of non-contact mechanical seal.Due to its small leakage,low friction power consumption and long service life,it is widely used in various rotary fluid machinery.Most scholars' research on upstream pumping mechanical seals mainly focuses on performance and parameter optimization,but the research on convection-solid coupling involves less.In this paper,the mechanical research of the pumping mechanical seal upstream of the oblique groove is taken as the research object.Theoretical studies on the flow field characteristics of the seal face,orthogonal test optimization,and unidirectional fluid-solid coupling analysis are carried out.Firstly,the overall structure,end structure,sealing mechanism,working principle,groove structure parameters and main performance parameters of the slant groove upstream pumping mechanical seal are introduced.Then,the Pro/E software was used to establish a three-dimensional model of the end face flow field of the upstream mechanical pump seal,and the end face flow field was numerically simulated by Fluent software.Ratio,groove width ratio,groove depth,liquid film thickness)and working condition parameters(pressure difference,speed)affect the sealing performance parameters.By designing the orthogonal test optimization scheme,the significance of the influence of structural parameters and working condition parameters on the sealing performance is analyzed.The results show that: the number of grooves,radial angle,groove depth,liquid film thickness,speed and pressure difference have a significant effect on the opening force of the seal end,the groove diameter ratio and groove width ratio have no significant effect on the opening force;The thickness of the liquid film,the speed of rotation and the pressure difference have a significant effect on the leakage amount of the sealing end face,and the radial angle,groove diameter ratio and groove depth have no significant effect on the leakage amount.Through the principle of comprehensive balance,the structural parameters of the pump mechanical seal upstream of the oblique groove were optimized,and the optimal combination of structural parameters of the groove was obtained.Finally,according to the optimized combination parameters,a three-dimensional geometric model of fluid-solid coupling of the mechanical seal upstream of the inclined groove is established,and the unidirectional fluid-solid coupling calculation is performed in ANSYS Workbench.The SiC,WC,YWN8 Three kinds of moving ring materials were compared and analyzed by finite element method to study the influence of materials and working condition parameters on stress and deformation.The results show that the maximum stress and the maximum deformation occur at the outer edge of the diagonal groove.The maximum stress gradually decreases with the increase of the rotation speed,and the rotation speed has basically no effect on the maximum deformation;the pressure difference has a greater influence on the maximum stress and the maximum deformation,and both It shows a linear increasing trend;compared with other moving ring materials,it is recommended to prefer SiC.The research results in this paper are of guiding significance for the design and parameter selection of upstream pumping mechanical seals with diagonal grooves.