基于光纤光栅的煤矿瓦斯压力传感器的研制

摘要

针对煤层瓦斯压力不能多点同步测量问题,提出一种基于弹性膜片的光纤光栅(fiber bragg grating,FBG)瓦斯压力传感器设计方案.采用膜片与腔体一体、光纤首尾开放的结构模式,并对封装后的传感器进行试验研究,针对FBG瓦斯压力传感器存在的温度-应力交叉敏感问题,进行了交叉敏感分析以及算法补偿,并对该传感器分别进行压力试验标定和温度影响试验标定.试验结果表明,该传感器压力范围0～10 MPa,温度灵敏度系数27.01 pm/℃,温度补偿后的压力灵敏度系数251.88 pm/MPa,与理论值接近.该传感器的结构模式可以有效避免安装误差和迟滞误差所带来的影响,同时便于组链开展多点分布式测量.%A design scheme of Fiber Bragg Grating (FBG)gas pressure sensor based on elastic diaphragm is proposed for multi-point simultaneous measurement on coal seam gas pressure.The sensor adopted the diaphragm and cavity as a whole and the fiber adopted the open-end mode,and the encapsulated sensor was used to do experimental research.Aiming at the temperature-stress cross-sensitivity problem of FBG pressure sensors,the solution of the temperature compensation was studied,and the sensor was calibrated by pressure experiment and temperature experiment.The experimental results show that the temperature sensitivity coefficient of FBG pressure sensor is 27.01 pm/℃ at the pressure range of 0 ～ 10 MPa,the pressure sensitivity coefficient after warming is 251.88 pm/MPa,which is close to the theoretical value.The structure of the sensor can effectively avoid the influence of installation error and hysteresis error and is convenient for achieving multi-point distributed measurement of group chains.