Leakage and wear characteristics of O-ring seals in nuclear power plant pressure-reducing valves: Parameter analysis and dual-objective optimization

Abstract

Within nuclear power plant hydraulic control systems, the O-ring seal in pressure-reducing valves is a critical component whose performance directly impacts system safety and stability. Failure modes such as leakage or excessive wear can cause abnormal oil pressure, potentially disrupting plant operation and leading to serious safety-related incidents. Therefore, this research investigates the leakage and wear characteristics of these O-ring seals. By integrating a trapezoidal leakage channel model with an Archard wear model, this study analyzes the effects of key parameters -including compression ratio, cross-sectional diameter, and rubber hardness - on sealing performance. Results demonstrate that increasing the compression ratio induces a nonlinear decrease in leakage rate but an approximately linear increase in wear. A larger cross-sectional diameter reduces leakage, while its influence on wear initially diminishes before intensifying. As material hardness increases, the leakage rate first rises sharply, then gradually decreases before increasing again, while the wear amount escalates. Moreover, the double-objective optimization approach based on the genetic algorithm was used to enhance the performance of the sealing system: the leakage rate was reduced from 0.069842  ${\mathrm{cm}}^3\cdot {\mathrm{s}}^{-1}$ to 0.023881  ${\mathrm{cm}}^3\cdot {\mathrm{s}}^{-1}$ , and the wear amount was slightly decreased from 0.0014631 mm to 0.0014532 mm. This work provides essential theoretical and methodological guidance for designing and optimizing reliable O-ring sealing systems in practical nuclear engineering applications.