| In order to further improve the sealing performance of dry gas seal,a new type of dry gas seal with spiral grooves was proposed in this research.taking the compressor dry gas seal as research object.The difference between the new spiral groove dry gas seal and the traditional spiral groove dry gas seal is that the new spiral groove has two radii of groove root.A"depression"structure was designed at the base of the traditional spiral groove to enhance its dynamic pressure effect and the radial length of the spiral groove is longer than that of the traditional spiral groove.In this research,the geometric model of the 1/N_gcalculation region of the new spiral groove was established by software of Solid Works.And use ICEM to divide the mesh for model.After that,the flie of mesh model was imported into the Fluent software for flow field analysis and calculation.The gas flim pressure distribution nephogram under various geometric parameters was obtained ater calculation and the influence of different geometric parameters(gas film thickness,groove depth,the number of groove,helix angle)on the gas film opening force,leakage and film stiffness of the new type of spiral groove dry gas seal was explored.The calculation results show that With the increase of the film thickness,the film opening force,leakage and film stiffness of the new spiral groove all increase.With the increase of grooving depth,the opening force,leakage amount and film stiffness also show an increasing trend,while with the increase of grooving number,the opening force,leakage amount and film stiffness firstly increase and then tend to be stable.With the increase of helix Angle,the film opening force of the new helix groove increases first and then decreases,while the leakage increases with the increase of helix Angle.Combined with a combination of factors.The sealing performance of the new spiral groove is the best when the film thickness is 3μm,the grooving depth is 5μm,the number of grooving is12,and the helix Angle is 15°We also use Solid Works to carry out geometric modeling of the traditional spiral groove to explore the comparison of the sealing performance of the new spiral groove and the traditional spiral groove under the same working conditions.The results show that with the increase of speed and inlet pressure,the dynamic pressure effect of the new spiral grooves and the traditional spiral grooves increases,and the film opening force,leakage and film stiffness of the two kinds of grooves all increase.The stiff-leakage ratio of the two grooves decreases with the increase of the rotating speed and the inlet pressure.But the sealing performance of the new spiral grooves is always better than that of the traditional spiral grooves,especially in the aspect of leakage.We use the Fluid Flow(Fluent)flow field analysis and calculation module and the Static-Structural Structural field analysis module in the Workbench platform.Then the two modules are connected to load the flow field pressure on the dynamic and static rings of the two grooved dry gas seals.Corresponding stress constraints and loads were applied to investigate the stress and strain results of two kinds of dry gas seal grooves under fluid-structure coupling.The calculation results show that the stress and strain of the new spiral grooves are always greater than that of the traditional spiral grooves under the same coupling condition.The stress strain of the moving ring is always greater than that of the static ring.The maximum stress and maximum shape variable of the two grooves increase with the increase of speed and inlet pressure.In this research,a new spiral groove dry gas seal structure is proposed,and the effects of different structural parameters(gas film thickness,groove depth,groove number,spiral Angle)and working conditions(rotating speed,inlet pressure)on its sealing performance are discussed.The stress and strain of fluid-structure coupling during its service were investigated.The simulation results provide some references for future experiments and applications. |
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