双槽阶梯槽干气密封性能研究

Study on Sealing Performance of Double Groove-Stepped Groove Dry Gas Seal

针对干气密封系统在高转速工况下密封性能差、泄漏量大的问题,提出一种双槽阶梯槽端面密封结构。采用CFD对比分析不同压力、转速下单螺旋槽、双槽阶梯槽、阶梯槽3种槽型的密封性能,探讨槽深、螺旋角对密封性能的影响,得出了双槽阶梯槽型优化的结构参数。结果表明:双槽阶梯槽在降低泄漏量和提高综合密封性能上要优于阶梯槽和单螺旋槽;在槽深为6μm、螺旋角为18°时双槽阶梯槽端面密封的刚漏比最大、泄漏量最低;与普通螺旋槽干气密封性能相比,在高速低压工况下,双槽阶梯槽干气密封承载力虽稍有下降,但刚漏比提升了21.74%、泄漏量降低了27.45%。

Aimed at the problem of poor sealing performance and large leakage of dry gas seal system at high speed,a double groove-stepped groove face seal structure was proposed.CFD was used to compare and analyze the sealing performances of single spiral groove,double groove-stepped spiral groove and stepped groove under different pressure and speed.The effects of groove depth and spiral angle on sealing performances were discussed,and the optimized structural parameters of double groove-stepped groove were obtained.The results show that double groove-stepped groove is better than stepped groove and single spiral groove in reducing leakage and improving comprehensive sealing performance.The double groove-stepped groove face seal has the largest stiffness to leakage ratio and the lowest leakage when the groove depth is 6μm and the helix angle is 18°.Under the condition of high speed and low pressure,compared with the performance of ordinary spiral groove dry gas seal,although the bearing capacity of double groove-stepped groove dry gas seal decreases slightly,the stiffness to leakage ratio is increased by 21.74%,and the leakage rate is reduced by 27.45%.