磁悬浮离心式压缩机的推力轴承喘振控制

摘要

压缩机等流体机械在流量减少到一定程度时会发生喘振.针对传统喘振控制方法结构复杂、响应慢、存在功率损失等缺点,提出了一种新的喘振控制方法.通过磁悬浮推力轴承改变压缩机叶轮的叶顶与压缩机蜗壳之间的叶尖间隙,进行喘振控制.通过正弦和方波参考信号跟踪,采用悬浮于不同位置的干扰信号扫频试验,验证了基于控制算法的磁悬浮控制能够满足改变叶尖间隙所需要的位置跟踪性能和悬浮于不同位置的稳定性.设计了基于质量流量反馈控制和基于输出压力反馈控制的控制策略,并进行仿真验证.结果表明:变叶尖间隙喘振控制能够有效起到喘振抑制作用,扩大压缩机稳定运行范围,为磁悬浮流体机械的喘振控制开辟了一个新的方向.%For fluid machinery,such as compressor,etc.,when the fluid reduces to a certain degree,the surge may occur.Aiming at the weakness of traditional surge control methods,e.g.,complex structure,long response time,and the power loss,etc.,a new control method is proposed.The impeller tip clearance between the top of the impeller and volute of the compressor is changed by adopting maglev trust bearing.Firstly,the maglev control algorithm is verified satisfying the tip clearance control performance and stability by sine and square wave signal tracking experiments and the interference signal frequency sweep experiments in different suspension location.Then,the control strategies based on mass flow feedback control and based on the output pressure feedback control are designed,and verified by simulation.The results show that the new control method changing tip clearance with thrust magnetic bearing can control the surge effectively and expand the range of stable operation of compressor.The research provides a new direction for surge control of magnetic fluid machinery.