光纤光栅原油压力传感器实验及其可靠性研究

介绍并制作了一种光纤光栅高温高压传感器,它由三种金属管组成,中央的弹性金属管将液体的压力转换为管子的机械伸长,周围金属管的长度只随温度变化。光纤光栅的两端分别固定在中央管及周围管的末端,随着压力管内液体压力的增加,光栅的中心波长随之增加,实现了对液压的传感。对该传感器的温度补偿进行了分析,设计了具有相同温度系数的压力传感光栅与温度传感光栅。并对传感器进行了高压实验和高温、高湿存储实验。结果表明,这种压力传感器在0~50 MPa之间灵敏度为31.7 pm/MPa。经过200℃高温存储16 h,及100℃沸水浸泡6 h,波长没有观察到明显衰退现象。

Study on Fiber Grating Petroleum Pressure Sensor and Its Reliability

A high pressure and temperature fiber grating sensor was presented. The sensor was implemented by using three metal tubes. The central elastic metal tube was used to convert pressure into longitudinal strain. The outer tube was only affected by temperature. Fiber grating was fixed on both end of central and outer tube, so as to sense the wavelength increment introduced by the pressure. Temperature compensation scheme was studied, and two fiber Bragg gratings (FBGs) (pressure sensing grating and temperature sensing grating) with similar temperature coefficient were designed. High pressure and high temperature/humidity storage tests were carried out. Results showed that the sensor during the condition of 0～50 MPa had a pressure sensitivity up to 31.7 pm/MPa. After storage of 16 hours under 200 ℃ and immersion into 100 ℃ water for 6 hours, the fiber grating wavelength showed no obviously decay.