A comprehensive multi-objective, multi-parameter and multi-condition optimization of a spiral groove in dry gas seals

Abstract

Dry gas seals are widely used in rotating equipment for fluid leakage control and operating efficiency enhancement, while the geometric parameters of the spiral groove affect its sealing performance significantly. Groove width ratio δ, groove length ratio α, and spiral angle β are the selected optimization geometric parameters for different objectives, including opening force Fo, film stiffness kz, and stiffness–leakage ratio Γ. The genetic algorithm and loop iteration optimization method are used to solve the multi-dimensional optimization problems under different working conditions, which are reflected in a new dimensionless number λ in the range 1 to 1000. Moreover, a concept of optimum spectrum is developed to obtain the global optimal geometric parameters. The performance comparison of two dry gas seals with different geometric parameters is conducted experimentally to verify the effectiveness of numerical results. Results show that both genetic algorithm and loop iteration optimization method can provide optimal geometric parameters for better sealing performance than single factor optimization, and the global optimal results were significantly influenced by working conditions and objectives. The multi-dimensional optimization methods and results presented in this paper provide a theoretical and experimental reference for designing dry gas seals in different working conditions to meet various sealing performance requirements.