Application And Software Implementation Of Distributed Temperature Sensing System In Extreme Environment

Distributed temperature sensing system is an optical fiber sensing system based on optical time domain reflection(OTDR)technology and Raman scattering effect.Compared with electronic sensing systems,it has the advantages of insulation,anti-electromagnetic interference,small size,simple layout,etc.It has a wide range of applications in many fields such as urban rail transit power detection and tunnel temperature monitoring.However,in extreme environments such as nuclear power plants(high temperature,high humidity,strong vibration,and strong ? irradiation),the radiation will cause wavelength-dependent radiation attenuation(radiation induced attenuation),which will seriously degrade the temperature measurement accuracy and temperature measurement distance of the system.In addition,the influence of high temperature,high humidity and vibration on the system needs to be studied.In view of the above problems,the following research work has been done in this paper.1.Briefly introduce the sensing principle and temperature demodulation principle of the distributed optical fiber temperature measurement system,analyze the hardware functions and selection of the system,and finally complete the preliminary construction of the distributed optical fiber temperature measurement system based on Raman scattering,and determine the measurement of the system The temperature accuracy is± 2 ?,the spatial resolution is 1 m,and the response time is 15 s.2.We analyzed the effect of ?-irradiation on differently doped quartz optical fibers.Combined with the irradiation experiments,it has been found that F can effectively improve the anti-irradiation performance of quartz optical fibers.The irradiation experiment assumed that the radiation source was ? photon energy of 1.25 MeV,the irradiation dose rate was 7000 Gry / h,and the total dose reached 2 MGry.The experimental results showed that the radiation-induced attenuation showed a nonlinear and rapid increase at the initial stage of irradiation,and then linear Growth,and there is no saturation trend.After the irradiation experiment,through the series of 50 ? ~500 ? thermal annealing experiments to study the effect of thermal annealing on reducing or even eliminating the optical fiber radiation attenuation,found that high temperature thermal annealing can effectively reduce or even eliminate the radiation attenuation,but it is not that the higher the temperature,the better the effect.3.Through radial and axial vibration experiments,the influence of vibration on the distributed temperature measurement system was studied.Using the two-end method to calibrate the random attenuation of Stokes light and anti-Stokes light caused by irradiation,and determine the selection and packaging of temperature measurement fiber The structure meets the needs in extreme environments,and its temperature measurement accuracy is ±1 ?,spatial resolution is 1 m,and response time is 5 s.4.Based on the Winform framework on Microsoft Visual Studio platform,using C# to develop system programs to optimize the temperature demodulation algorithm.The software developed at the same time can combine temperature data with spatial location,and can dynamically display the temperature changes.The ACESS database is used to store the parameter data,and the SQL Sever database is used to store the temperature and the original signal(the light intensity signals of the Stokes light and the anti-Stokes light).