Design Of Mine Detector With High And Low Methane Concentration

Coal mine gas explosion is the main reason for the frequent coal mineaccidents in recent years. Reasonable and effective concentration of methanedetection technology and timely treatment can effectively reduce the occurrenceof coal mine accidents. Therefore, the design of high-precision coal minemethane concentration detection equipment is especially important forproduction safety.Through comparing and studying the current gas detection technology onhome and abroad, according to the advantages and disadvantages of variousdetection principles, the thesis uses a combination measurements manner todetermine the high and low concentrations of methane full range detection. Inlow concentrations stage, the catalytic combustion sensor is used formeasurement, in order to avoid impulse and binary problems at highconcentration, it powered by thermostatic control; In high concentrations stage,thermal conductivity sensor is used for measurement, and the introduction of thetemperature compensation mechanism to reduce the impact of ambienttemperature on the measurement results; In order to improve the measurementaccuracy, avoiding the traditional practice of switching transitions in differentconcentrations, delays and other issues, the thesis adopts combined output mode.The design of the detector uses a PIC16F887as the digital processing unit,designs the hardware circuits, and writes software programs by using C language.The monitor outputs industry standard frequency to monitoring system for real-time monitoring, when the measure result is above a preset threshold, thedetector sends sound and light warning signals. Considering all aspects ofinterfering factors in the design, the design adds the hardware and software anti-jamming measures to improve the measurement accuracy and stability of the detector.After prototype debugging, thesis does prototype detection experiments bystandard concentration gas. After analyzing of the experimental results, it is notdifficult to see that the detector has a favorable temperature compensation effectand high sensitivity, while the measurement accuracy is far higher than thenational standard regulations, and fast response, high reliability, good stability,and good practical promotional value.