| As the world's largest coal producer and consumer,coal will remain the main energy source in China for a long period of time.In recent years,in the face of the contradiction between coal production cost,scientific production capacity,profit space,personnel safety,mine disaster and safe production,the intelligent mining of coal has become the demand and inevitable direction of the technological revolution and upgrading of the coal industry.It is the core and key to achieving safe and efficient production in the coal industry.Intelligent sensing is one of the core elements of intelligent mining in coal mines,and the key technology of intelligent perception is monitoring technology.Mining engineering environment has the characteristics of complexity,concealment and suddenness,and there are only a few of types of FBG sensors currently available in the field of coal mining sensing,and simplex monitoring parameters,which could not meet the needs of complex on-site monitoring underground.Fiber Bragg Grating(FBG)sensing technology provides new means and methodology for solving the problem of safe,efficient,intelligent sensing of mining basic information,due to its intrinsic safety,high measurement accuracy and good networking capabilities.In this paper,based on the weak technology existing in the sensing level of coal mine intelligent mining,theoretical analysis,numerical calculation,finite element simulation,laboratory test,physical model test and engineering test have been used to carry out research work on intelligent sensing theory and key technologies of multi-parameter FBG in coal mining,which helps to improve the intelligent sensing level and monitoring efficiency of coal mining,and lays a foundation for further research and application of intelligent mining,and represents reference values for China's coal mining enterprises to promote intelligent construction.The main research work is as follows:(1)Through the classical theory of fiber transmission,the reflection spectrum characteristics and distribution of the FBG are numerically calculated.The effects of the FBG intrinsic parameters on the reflection spectrum characteristics,such as the length of the gate and the refractive index change,are studied.The FBG sensing principle based on the wavelength coding method is analyzed.And,the FBG strain,temperature,quasi-distribution sensing characteristics are discussed herein.(2)Based on the practical application of FBG in coal mine,three different methods of encapsulating FBG on the surface of the matrix are proposed.The FBG-matrix strain sensing transfer model is established.The mathematic equations of the actual strain of the matrix and the perceived strain of the FBG are theoretically derived.The FBG strain sensing transmission factor is proposed,and the strain sensing distribution law of FBGmatrix in the pasting length range is revealed.The influencing factors of FBG-matrix strain sensing transmission are analyzed.The finite element simulation and experiment verify the strain sensing transmission effect.(3)According to the coal mining basic information monitoring requirements and application environment characteristics,based on theoretical mechanics,finite element simulation and experimental test analysis methods,a series of mine multi-parameter FBG sensors were independently developed,and the concept of FBG intelligent sensing system for coal mining was proposed.The FBG sensing network topology and networking mode are used,and a large-capacity,multi-parameter FBG intelligent sensing system for coal mining is constructed,and real-time online monitoring software is independently developed.(4)The model test and engineering application of FBG sensors and the sensing system thereof were carried out,which realized the continuous,automated and quasidistributed measurement of multi-parameter basic information in coal mining process,revealing the feasibility and superiority of FBG sensors and sensing system in mining engineering application. |
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