Optimization design for mechanical seals in reactor coolant pumps based on a fluid–solid strong-interaction model

Abstract

The study on the mechanism and performance of the mechanical seals in reactor coolant pumps (RCPs) is very important for the safe operations of pressurized water reactor power plants. By exploring the operating mechanism of the first seal of the hydrostatic mechanical seal in RCPs, an analytical fluid–solid strong-interaction model of the seal is proposed in this article. The model holds that the mechanical deformations of the seal assembly are dominated by the deflections of the seal rings, and this idea is demonstrated by the numerical simulation result of a fluid–solid interaction (FSI) model. Using the analytical FSI model, the regularity that the leakage rate of the first seal varies with the differential pressure in a RCP is obtained, and compared with the operational data, which is used to verify the model. Based on the understanding of the reliability of the seal, a dimensionless parameter Λ that acts as an attribute to the reliability is proposed in this article. Using the analytical FSI model and Λ as the optimization algorithm and optimization object, respectively, the optimum designs about the seal faceplateconfigurations are performed. Also, the specific optimization conclusions are given simultaneously.