小型探针式FBG流量温度复合传感器

A small probe-type flow and temperature composite sensor based on fiber Bragg grating

针对光纤布拉格光栅流量温度复合传感器存在压损大、量程窄、结构复杂的问题,提出了一种基于光纤布拉格光栅的小型探针式流量温度复合传感器。基于悬臂梁弯曲变形理论和光纤布拉格光栅传感机理,结合管道内流体流速分布特性,建立探针式流量温度复合传感模型,揭示了光纤布拉格光栅中心波长漂移量与流量温度的映射关系;采用有限元分析法研究了探针结构应变分布特性,确定了光纤布拉格光栅的最优粘贴位置;搭建实验系统平台,进行了温度和流量实验。温度实验结果表明,传感器的灵敏度为25 pm/℃,是裸光纤布拉格光栅的2.3倍,重复性误差为3.621%;流量实验结果表明,传感器测量范围为2~30 m^(3)/h,重复性误差为2.141%。与现有光纤光栅流量温度复合传感器相比,复合传感器压损更小、量程更宽。

Aiming at the problems of huge pressure loss, narrow measurement range and a complex structure of a fiber Bragg grating(FBG) flow and temperature composite sensor, this paper proposes a small FBG-based probe-type flow and temperature composite sensor. Firstly, based on the bending deformation theory of cantilever beams and the FBG sensing principles, the probe-type flow and temperature composite sensor model is established combined with the flow velocity distribution characteristics of the fluid in the pipeline, and the mapping relationship between the central wavelength drift and flow and temperature of FBG is revealed. Secondly, the strain distribution characteristics of the probe structure are studied by finite element analysis method, and the optimal sticking position of the FBG is determined. Finally, an experimental system platform is established, and temperature and flow sensing experiments are carried out. The results of the temperature experiment show that the temperature sensitivity of the sensor is 25 pm/℃, which is 2.3 times that of the bare FBG, and the repeatability error is 3.621%. The flow experiment results show that the measurement range of the sensor is from 2 m^(3)/h to 30 m^(3)/h, and the repeatability error is 2.141%. Compared with the existing FBG flow and temperature composite sensors, the proposed sensor has smaller pressure loss and wider measurement range.