Deterministic method for considering the influence of bottom surface roughness on dry gas seal performance
MAO Wenyuan1,2, SONG Pengyun1,2*, DENG Qiangguo2, XU Hengjie2
(1.Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China; 2.Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
Abstract:In order to study the influence of surface roughness at spiral groove bottom on the perfor-mance of dry gas seal, a groove bottom surface roughness model with a sinusoidal curve along the radial direction of the seal end surface was established, the influence of wavelength λ on the performance of dry gas seal were analyzed within the range of a sampling length Lr, and then the sine wave number n was determined, that is, n is 10 and the wavelength λ is 0.08 μm, the gas pressure distribution of the seal end surface gap was obtained by a approximate analytical method, the effect of surface roughness on the opening force and the leakage at different groove depths and gas film thicknesses were analyzed. As to the operating condition investigated, the results show that with respect to smooth groove bottom, the absolute value of maximum relative error for opening force is 0.12% and that for leakage rate is 0.31% when the groove bottom surface roughness Ra is 0.4 μm; the absolute value of maximum relative error for opening force is 0.50% and that for leakage rate is 1.26% when Ra is 0.8 μm. It indicates that the influence of bottom surface roughness on the sealing performance can be ignored when Ra≤0.8 μm at common operation, whereas the surface roughness Ra of the groove bottom should be less than 0.4 μm when the gas film thickness at non-groove region is smaller than 2 μm.
毛文元,, 宋鹏云,, 邓强国, 许恒杰. 底表面粗糙度影响干气密封性能的确定性方法[J]. 排灌机械工程学报, 2018, 36(12): 1294-1299.
MAO Wenyuan,, SONG Pengyun,*, DENG Qiangguo, XU Hengjie. Deterministic method for considering the influence of bottom surface roughness on dry gas seal performance. Journal of Drainage and Irrigation Machinery Engin, 2018, 36(12): 1294-1299.
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