Research On Impact, Flow And Temperature Monitoring Technology Based On Optical Fiber Sensor

Optical fiber sensing technology is a new sensing technology with the rapid development of optical fiber and optical communication technology. It has the characteristics of optical fiber and optical measurement, such as excellent electric insulation performance, strong ability of anti electromagnetic interference, high sensitivity, large dynamic range, wide frequency band, easy to realize the remote monitoring of the measured signal. In this paper, it respectively studies the M-Z sensing technology, meter pipe flow and contact temperature monitoring technology based on Fiber Bragg grating sensor, and composes the relevant signal processing software. The main research work includes several parts as follows:Firstly, according to the demand of typical mechanical structure dynamic load monitoring, this paper researchs the main factors affecting the polarization properties of optical fiber M-Z sensing system,such as the phase characteristic and the influence of the stability of the system. Using numerical simulation to get the effect on polarization interference characteristics of the system which the fiber bending, the external environment stress and temperature have, and analyzing the influence on the system output intensity and phase delay which initial phase difference and sound source signal exert. The phase compensation technique is used to eliminate the signal fading caused by the phenomenon of phase drift.Secondly, the optical fiber M-Z interferometer sensing system is constructed to monitor dynamic load of typical mechanical structure. Besides, phase modulator is developed to compensate disturbance of interference signal. Optical fiber sensing probe is designed to acquire clamped aluminum alloy plate structure’s impact signal. On this basis, optical fiber monitoring system is built to monitor the pipeline’s impact.Again, according to the demand of pipe flow monitoring, a kind of fiber grating sensor is designed for pipeline’s two state,liquid / gas, flow measurement. Fiber sensing model based on the fan type sensitive mechanism is studied,and influence law of Blade Parameters on the flow monitoring sensitivity is obtained through the numerical simulation. With the help of the FLUENT simulation software, pressure loss characteristics which is caused by the flowing liquid under the different number of leaves and different leaf diameter ratio is obtained. On this basis, industrial pipeline fluid online monitoring system based on Fiber Bragg grating velocity sensor is built.Finally, according to the requirements of temperature monitoring power system, fiber Bragg grating temperature sensing probe which is not affected by the force is designed. The integrated temperature calibration method improves the accuracy and stability of temperature monitoring system, and a data acquisition and control system based on LabVIEW is constructed to realize the electric energy meter verification process’ s function, such as medium contact temperature signal’s display, storage and early warning.