Thermal-liquid–solid coupling characteristics of wavy-end-face mechanical seal for reactor coolant pump

Abstract

Mechanical seal is one of crucial safety measures for a reactor coolant pump (RCP) in nuclear power plant. To evaluate the structural design of the rotor–stator components of seal, a coupled thermal-liquid–solid model for numerical simulation of a wavy-tilt-dam (WTD) end-face mechanical seal is established, based on the programming of finite element method (FEM) and Multiphysics software COMSOL. The sealing performance of the seal, thermal field, deformation, and von Mises stress distributions of solid are accordingly analyzed and discussed. It is shown that increasing the sealing pressure will promote a convergent deformation of the seal rings, and weakening the hydrodynamic effect of the sealing. The thermal deformation of the seal ring also tends to enhance the tapered degree of the seal end-face, which strengthens the hydrostatic effect. However, as pressure increased, the effect of pressurized sealing state on the deformation prevails the thermal effect. It is also found that the leakage rate obtained by simulations agrees with the experimental results conducted on an actual WTD mechanical seal, and the possible reasons for deviation are discussed.