反旋流对梳齿密封动力特性影响机理及有效性
Influence of shunt injection on dynamic characteristics of labyrinth seals and its effectiveness
张乃丹 1张万福 1周庆辉 1顾乾磊 2李春1
作者信息
- 1. 上海理工大学能源与动力工程学院,上海 200093
- 2. 东南大学能源与环境学院,南京 210096
- 折叠
摘要
对比分析了不同预旋比下反旋流装置对梳齿密封各腔室内压力、周向流速、周向旋流增长率及动力特性系数,对反旋流梳齿密封的有效性进行定量分析与判别.研究表明:反旋流装置对密封周向流动有较强的抑制作用,且对各腔室压力有不同影响,其中对C3～C6腔室压力作用效果较明显;引入周向旋流增长率衡量反旋流装置作用效果,添加反旋流装置后,密封周向旋流增长率沿泄漏方向降低至C8腔室,在C9腔室处略有回升,无反旋流密封基本保持不变.添加反旋流喷嘴使C3～C6腔室直接阻尼增大,且各腔室交叉刚度均减小,各腔室有效阻尼提高,总有效阻尼增大稳定性增强.预旋比使C1～C2腔室的直接阻尼有显著变化.添加反旋流喷嘴后,腔室交叉刚度在高预旋比下减小更多,有效阻尼受预旋影响较小,反旋流对进口正预旋有较好抑制作用.
Abstract
The influences of adding or not adding the shunt injection with different preswirl ratios on the pressure,the circumferential flow velocity,the growth rate of the circumferential swirling flow and rotordynamic characteristics coefficients in each seal cavity were compared and analyzed.The effec-tiveness of the shunt injection was quantitatively analyzed and evaluated.Studies showed that the shunt injection device had a strong inhibitory effect on the circumferential flow of the seal,and also a different influence on the pressure in each cavity,with a more obvious influence on the pressure in C3—C6.The growth rate of the circumferential swirling flow was introduced to measure the effect of the shunt injection.With the addition of shunt injection,the circumferential swirling flow growth rate for labyrinth seal was reduced along the direction of leakage to C8,and slightly rebounded at C9.The labyrinth seal without shunt injection remained largely unchanged.The shunt injection increased the direct damping of C3—C6,decreased the cross-coupled stiffness of each cavity,thus improving the effect damping of each cavity,and enhancing the system stability.The preswirl ratio influenced the direct damping of C1—C2.The shunt injection made the cross-coupled stiffness of each cavity decrease more at the high preswirl ratio.The effect damping was less affected by the preswirl ratio,thus the shunt injection had a better suppression effect on inlet the positive preswirl ratio.
关键词
反旋流/梳齿密封/周向旋流/动力特性/计算流体力学Key words
shunt injection/labyrinth seal/circumferential swirling flow/rotordynamic characteristics/computational fluid dynamics引用本文复制引用
基金项目
国家自然科学基金(51875361)
上海市自然科学基金(20ZR1439200)
出版年
2024
NETL
NSTL
万方数据