Basic Research Of Mine Micro-nano Ionization Methane Sensor Based On TiO₂ Nanotubes

Sensors with excellent performance play an important role in improving control accuracy and control quality in the field of control system.For the coal industry,it is necessary to quickly and accurately detect the CH4 concentration.By the combination of experiment and simulation,this thesis mainly studied the feasibility of using ionized gas sensors for methane gas detection.In this thesis,the TiO2 nanotube electrode material was prepared by anodic oxidation method.The material was characterized and then by using this material the gas sensor was assembled.The sensor test system was built.The volt-ampere characteristic curve of the ionized gas sensor was obtained through experiments.The simulation model of micro-nano ionization gas sensor based on fluid-chemical dynamics hybrid method was established by constructing control equations.The characteristic curve of current density with voltage was obtained.The normalized method was used to process experimental data and simulation data.The law of development verified the reliability of the simulation model of gas discharge between sensors.By calculating the degree of electric field distortion caused by space charge,the key parameters of methane non-spark discharge were analyzed,and the safe discharge mechanism of methane was explained which based on the electron transport process.Analyzed the evolution process of the positive ion composition and the electron energy with the methane concentration.Finally,the relationship between the macroscopic electrical characteristics of the device and the ionization effect of methane was established.The sensitive mechanism of the micro-nano ionization device was improved and its sensitivity was analyzed.The results show that the ionization sensor model can be used not only for mine methane gas detection and sensing.It can also be used for methane concentration detection in a wide range of ranges;the sensor has high linearity detection,R-sq is 0.997;the maximum sensitivity is 30A/ppm·m2;the response speed of the device is 10-2s.Finally,the effects of two different electrode structures on sensor performance were compared and analyzed.The results show that the gas discharge current density obtained under the micro/nano structure is one order of magnitude higher than that of the flat structure,and the linearity is better under the micro-nano structure and the sensitivity is higher.The mechanism simulation study in this paper lays a theoretical foundation for the preparation of mine ionized methane sensors,and has a good reference for the preparation of high performance gas sensor for smart mines.