基于近红外技术的小管道油膜监测方法研究

Research on small pipeline oil film monitoring method based on near infrared technology

针对油气润滑系统中由于润滑油流动异常导致高速电主轴轴承温升过大的问题。提出利用近红外光学检测技术,采用红外对射结构,将近红外光平行照射在润滑管线上,并通过光电探测器在管线的另一端接收透射光信号,实现小管道内油膜的实时监测。硬件电路包括红外发射电路和红外接收电路,通过信号采集卡对不同气压下的油气两相流的透射光信号进行采集,在时域中分析管内油膜厚度和周向油液分布与气压的关系。对信号进行数字滤波,使用现代功率谱估计自回归模型,从功率谱中观察到“双波峰”现象。在LabVIEW环境下编写监测程序,实现对油气润滑系统中气压不足、油路断油、正常运行三种状态下的实时监测。研究结果表明:近红外光电技术能够应用于小管道油膜监测,可实现出油口油液流动异常的实时预警。

Aiming at the problem that the temperature rise of high speed electric spindle bearings is too large due to abnormal oil flow in oil and gas lubrication systems.It is proposed to use the near infrared optical detection technology,using infrared thru-beam structure,near-infrared light parallel illumination on the lubrication pipeline,and receive the transmitted light signal at the other end of the pipeline through the photodetector to achieve real-time monitoring of the oil film in the small pipe.The hardware circuit includes an infrared transmitting circuit and an infrared receiving circuit,which collects the transmitted light signal of the two-phase flow of oil and gas under different air pressures through the signal acquisition card,and analyzes the relationship between the oil film thickness and circumferential oil distribution in the tube and the air pressure in the time domain.The signal is digitally filtered,using a modern power spectrum estimation autoregressive model,and the phenomenon of"double crests"is observed from the power spectrum.In the LabVIEW environment,the monitoring program is written to realize real-time monitoring of the three states of insufficient air pressure,oil circuit oil outage and normal operation in the oil and gas lubrication system.The results show that the near infrared photoelectric technology can be applied to the monitoring of oil film in small pipelines,which can realize the real-time early warning of abnormal oil flow at the outlet.