Thermo-Elasto-Hydrostatic Effect Analysis of the Double Tapered Hydrostatic Mechanical Seals for Reactor Coolant Pumps under the Influence of Flow Regime

Thermo-elastic deformation of a hydrostatic mechanical seal for reactor main coolant pumps plays an important role on seal performance due to the operation at high-pressure, high-speed and wide temperature range. A thermo-elasto-hydrostatic multi-physics coupling model is established for a double tapered face seal with convergence gap by considering the variation of dynamic viscosity with fluid pressure and temperature, heat transfer between lubrication film and seal rings and the deformation of end face. FDM and FEM are used to solve the control equations. The effects of thermo-elastic deformation and the misalignment angle of seal rings on seal performance and the comparative analysis of flow regime under the different misalignment angles of the seal rings are studied. It is found that the double tapered hydrostatic mechanical seal has larger turbulence region and transition region than the single tapered hydrostatic mechanical seal. The misalignment of the seal ring can change the flow regime. The face temperature will be decreased because of the enhanced effect of heat convection under the turbulence regime; Seal medium pressure has great influence on the seal performance and the speed of the rotor change the film stiffness apparently.