涡旋压缩机轴向动态间隙的实验测量

Measurement of Axial Dynamic Clearance in Scroll Compressor

设计了采用电涡流位移传感器测量喷水涡旋空气压缩机轴向间隙的实验方案和步骤.传感器采用偏移安装的方式,避免了动涡盘可能对传感器探头造成的损坏,并阐述了安装要点.编制了基于虚拟仪器技术的数据采集系统来记录和保存实验数据.测量结果表明:喷水涡旋空压机的轴向间隙在不同转速下变化较大,低转速和高转速下的典型值为75μm和49μm;涡旋空压机轴向间隙比涡旋制冷压缩机的轴向间隙大.测量结果输出波形的频率能够反映动涡盘掠过探头的时间间隔,因此可以用电涡流位移传感器测量涡旋压缩机的转速,提供了一种测量压缩机转速的方法,可对变速压缩机动态特性研究时转速值的确定提供帮助.总的来说,电涡流位移传感器结构简单、灵敏度高、静态和动态性能好、输出信号强,可以满足涡旋压缩机轴向间隙的小位移量的测量要求.

An experimental procedure was designed to measure the dynamic axial clearance in a scroll air compressor with water injection by using a eddy current displacement sensor. To protect the eddy current sensor probe, the sensor was mounted with an offset installation method. The data acquisition system was programmed to record and save the experimental data. The experimental results show that the axial clearance varies with the rotational speed of the compressor and the typical value of axial clearance at low and high speed is 75 μm and 49 μm, respectively. The axial clearance in the scroll air compressor is larger than that in the refrigeration scroll compressor. In addition, the frequencies of signal pulse can reflect the change of rotational speed on the basis of the output voltage signals. A new method that could accurately measure the rotary speed of scroll compressors was proposed.