磁悬浮压缩机顶隙调压模型与实验

风压紊乱是造成压缩机旋转失速、喘振等故障的直接原因,磁悬浮压缩机具有主动控制磁悬浮转子轴向位移对风压进行调控的优势。通过建立主动磁轴承轴向控制的动力学方程,首先,分析了磁悬浮转子稳定悬浮及轴向位移调整原理;其次,采用对磁悬浮压缩机风压性能有决定性影响的转速、叶轮高度、叶轮顶端间隙等参数,建立了磁悬浮压缩机叶轮顶隙与蜗壳出口风压之间关系的数学模型;最后,以30kW磁悬浮压缩机为实验对象,在叶轮顶隙分别改变0.1mm及0.2mm时,对出口风压及流量进行采集与分析。实验结果表明,磁悬浮压缩机蜗壳出口风压在数值上与所建数学模型的解算值契合度较高,并且叶轮顶隙对其有显著影响。针对压缩机不同故障状态,可依据数学模型选择不同叶轮顶隙进行调节。

Model and Experimental Research on the Relation Between Pressure and Impeller Clearance of Magnetic Levitation Compressor

The wind pressure disturbance is the direct cause of compressor rotating stall and surge. The magnetic-levitation compressor has the advantage of controlling the axial displacement of the magnetic levitation rotor to achieve the adjustment of compressor wind pressure. The principle of stabilizing suspension and axial displacement of magnetic levitation rotor is analyzed by establishing the dynamic equation of axial active bearing. A mathematical model of clearance and wind pressure is established by using parameters such as speed of direct relation of wind pressure, impeller height and tip clearance of impeller based on the above analysis.An experiment is carried out on the 30 kW magnetic-levitating compressor. Through data mining, it can be found that when the top gap of the impeller changes 0.1 mm and 0.2mm respectively,the numerical value of the wind pressure is very similar to that of the mathematical model. The experimental results also show that the tip clearance of impeller has a significant effect on the compressor wind pressure. For different fault states of the magnetic levitation compressor, different tip clearance of impeller can be selected to adjust the compressor according to mathematical model in this thesis.