中压低温透平膨胀机轴封封严特性研究

发布时间：2018-11-19 21:47

【摘要】：采用现代计算流体力学方法对PT1230中压低温透平膨胀机轴封内的三维定常黏性流场进行数值模拟,研究4种齿形(矩形齿、勾形齿及齿距不同的2种三角形齿)、3种进排气稳压结构共计12种密封方案的封严特性和流场细节。研究结果表明:密封齿的齿形对泄漏量的影响很大,其中齿距较大的三角形齿由于其具有较大的密封腔室,节流膨胀充分,密封性能最强,但是增加了密封的轴向长度;齿封的密封效果主要依赖于齿尖和外端壁的节流间隙,缩短该间隙,齿尖区域的压力梯度增大,密封效果增强;研究的4种齿形中,采用单进单出式的进排气方式时泄漏量最小,采用单进双出且排气口接近进气口的进排气方式时泄漏量最大。研究结果为合理地设计轴封开口位置、选择适宜的轴封长度,为改善密封效果提供了参考。
[Abstract]:Three dimensional steady viscous flow field in shaft seal of PT1230 medium pressure and low temperature turbine expander was numerically simulated by modern computational fluid dynamics method. Four kinds of tooth shapes (rectangular tooth, hook tooth and two triangular teeth with different pitch) were studied. Sealing characteristics and flow field details of 12 sealing schemes for three intake and exhaust pressure stabilizing structures. The results show that the tooth shape of the seal tooth has a great influence on the leakage, among which the triangular tooth with large tooth spacing has a large chamber, which has sufficient throttling expansion and the strongest sealing performance, but the axial length of the seal is increased. The sealing effect of the seal mainly depends on the throttling clearance between the tooth tip and the outer end wall, which shortens the clearance, increases the pressure gradient in the tooth tip region, and enhances the sealing effect. Among the four kinds of tooth profile studied, the leakage rate is the smallest when the single inlet and single output mode is used, and the maximum leakage is when the exhaust port is close to the intake and exhaust port by using the single inlet and double exit mode. The results provide a reference for the reasonable design of shaft seal opening position and the selection of appropriate shaft seal length.
【作者单位】：北京石油化工学院;
【分类号】：TH136

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