Deformation Analysis And Optimization Design Of Liquid Film Seal Considering The Viscosity-Temperature Effect

For high-temperature,high-pressure and high-speed mechanical seal,sealing ring will inevitably produce serious force deformation and thermal deformation.Because the fluid film thickness between the seal face is only micron grade,even small deformation can produce important influence on the sealing performance and working stability.So researching the force deformation,thermal deformation and force-thermal coupling deformation of high parameter seal has important significance.In this paper,the high-temperature pump is selected as the object of study.Calculating the seal ring's force-thermal coupling deformation,and based on the calculating result proposing effective deformation Controlling measures that can provide a reference for engineering practice.Temperature difference between inner diameter and outer diameter of the calculation model is 200 ?,ignoring viscosity-temperature effect will cause much bigger calculation error.So in this paper,under the premise of considering viscosity-temperature effect,studied the rotating and static ring's flow field,temperature field,force-thermal coupling deformation and seal ring stress.We studied seal ring radial taper and fluctuation degree in the circumferential direction.And also studied deformation's influencing factors,such as blocking fluid's pressure,rotational speed and the temperature difference between inside and outside diameter.The results showed that: the rotating ring generates negative taper divergence deformation,along outer diameter to inner diameter the static ring firstly generates negative taper divergence deformation,about to reach the bottom of the spiral groove,the static ring's deformation becomes positive taper convergence,but the average taper of static ring is still negative,waviness in the circumferential direction is much smaller compared to the radial taper,can be neglected,maximum stress of the rotating ring is located at the contact face of rotating ring and rotating ring seat,maximum stress of the static ring is located at the contact face of static ring and the stuck ring as well as the contact face of static ring and the seals,stress distribution inside of the seal ring is more uniform,blocking fluid pressure has little influence on seal ring's coupling deformation and seal ring's coupling deformation increase with the increasing of speed and temperature difference.According to the calculation results of seal ring's force-thermal coupling deformation,and based on the principle of parallel plane,the paper proposes effective deformation controlling measures from the following three aspects.That is the seal ring material,the structure of the seal ring(including axial length and radial width of the seal ring)and new structure of the seal ring.This provides theoretical guidance for the seal ring's optimal design.The results showed that: in order to control the deformation of the seal ring,the elastic modulus and the thermal conductivity of the material should be large and the thermal expansion coefficient should be small,increasing seal ring's axial length can reduce the coupling deformation,through opening cylindrical bore in rotating ring,leading a portion of fluid back to the inner diameter side,can significantly reduce seal ring's coupling deformation.