Development Of Electrical System For Methane/Carbon Monoxide Detector In Coal Mine

There will be harmful coal gas leakage in the mining environment.Alkanes are the most abundant.The highest content is methane.Under certain conditions,coal gas will cause explosion accidents,and carbon monoxide is usually accompanied in the early stage of coal dust combustion.Methane and carbon monoxide can harm the mining personnel.Methane and carbon monoxide are flammable,and may cause the possibility of coal mine explosions,causing secondary disasters such as coal mine fires and mine collapses.Infrared gas detector can monitor the gas concentration under the mine in real time,which is convenient for personnel to make predictions and take measures to reduce the occurrence of harm.At present,infrared gas detectors based on TDLAS technology are widely used due to its high sensitivity,low detection limit and other advantages.TDLAS detector includes optical system and electrical system.When the instrument fails,there will be electric sparks or thermal effects,and cause gas explosion.Therefore,strict standards for the circuit design of the detector are required.Intrinsic safety apparatus refers to the entire circuit of the equipment.It requires that no sparks or thermal effects generated under specified test conditions will ignite the specified explosive mixed composition.Thus,it is necessary to develop a gas detector for coal mine methane and carbon monoxide,and the electrical system of the detector should meet the requirements of intrinsic safety design.Firstly,this paper introduces the background of the research and explains the necessity of developing electrical system of the detector,and introduces the gas detection technology and intrinsic safety equipment.Secondly,this paper introduces the TDLAS technology and intrinsic safety theory,including the principle of infrared absorption spectroscopy,Lambert-Beer's law,direct absorption spectroscopy and wavelength modulation spectroscopy,and methods of intrinsically safe circuit design.Thirdly,this paper focuses on the development of the detector's electrical system,including the design of hardware circuit module and software development process.Finally,the electrical system is integrated,and methane and carbon monoxide experiments are performed,as well as functional verification experiments of electrical systems.The monitoring personnel can observe the laser working temperature and current,gas chamber temperature and humidity,methane and carbon monoxide gas concentration values and dynamic change curves at the interactive interface.The functional verification experiments of the electrical system show that the electrical system of the detector has certain reliability and stability.