Research And Software Design Of Distributed Coal Mine Goaf Monitoring System Based On Temperature Sensing Fiber

Distributed Raman temperature measurement technology based on temperaturesensitive fiber is a technique for real-time monitoring and localization of temperature field distribution along the direction of temperature-sensing fiber by using the temperature-sensitivity effect of Raman scattering combined with optical time-domain reflection technology.It has been widely used in the safety monitoring of coal mines,high voltage wire transmission,oil and gas pipelines,subway tunnels,etc.In this thesis,the theory,system scheme,demodulation algorithm,signal processing and software design of distributed Raman monitoring system based on temperature-sensitive fiber are deeply researched and analyzed.The following research work is completed:(1)Based on the in-depth study of Raman scattering theory and optical time domain reflection technology,a distributed Raman temperature demodulation intelligent monitoring system based on temperature-sensitive fiber is designed according to the actual needs of coal mine goaf.the demodulation system and its temperature calibration device are completed.(2)A new distributed Raman temperature demodulation method combining the compensation function method and the fitting method is proposed by studying and analyzing the law of the Raman ratio of multiple acquisition points on the temperature-sensitive optical fiber at different temperatures.This method achieves unified compensation for system jitter,propagation loss of signal light in optical fiber,and influence of external environment on pulsed light.(3)Through the research on the acquisition card,its underlying driver and the actual needs,the temperature demodulation algorithm program is designed,the temperature and location information of the distributed fiber along the line are analyzed.the high-concurrency Redis database was used to realize the information communication and data transmission with the host computer.The design of the monitoring system software and visual interface was completed,and the fire safety monitoring of the mined-out area of the coal mine goaf was realized.(4)The manufacture and test of the distributed coal mine goaf monitoring system based on temperature-sensitive fiber were completed.The new method combining compensation function and curve fitting was used,and the parameters of the system were optimized to achieve a temperature monitor more than 10 km.