Research On Temperature And Pressure Compensation Correction Method Of Mine Laser Methane Sensor Detection Error

Gas explosions and outburst risks have seriously affected the safety of life of underground workers and the safety of equipment and property.Accurate and real-time detection of the iconic gas CH4 in the gas is very important for guaranteeing the safe and efficient production of mines and the safety of underground workers.The detection accuracy of the existing mine gas detection device is susceptible to environmental factors and produces large errors.Therefore,this paper uses coordinated diode laser absorption spectroscopy(TDLAS)to achieve high-precision real-time detection of CH4 gas.The main work is as follows:By analyzing the experimental principles of TDLAS and related theories of application,the system's transmitting unit,absorption cell and receiving and data processing unit are designed,and an experimental system for detecting the concentration of CH4 gas based on TDLAS technology is built.The experiment tested four groups of CH4 gas with concentrations of 400ppm,500ppm,600ppm,and 700ppm.The experimental results show that:-5??10?,the concentration rises with the increase of temperature.When 10?-50?,The concentration decreases slowly;during the pressure increase from OkPa to 60kPa,the concentration gradually decreases with the increase of pressure.By exploring the influence of temperature and pressure on the absorption spectrum of CH4,the deep reasons of the influence of temperature and pressure on the measured concentration were analyzed.Then,the multiple linear regression method was used to fit the temperature and pressure to the CH4 concentration data,and the temperature and pressure were obtained.The fitting relationship of CH4 concentration provides a reference for the trend prediction of CH4 gas concentration detection under the mine based on TDLAS technology.In order to eliminate the errors of temperature and pressure on the detection data,three concentration correction models for CH4 gas,BP,GA-BP and PSO-BP,were established to compensate the temperature and pressure of the experimental data.The prediction and evaluation of the three correction models were analyzed and comparedAccording to the index,PSO-BP is the most effective temperature and pressure compensation correction model.The relative error after compensation reaches 1.42%.It can be used in the gas concentration monitoring module,which significantly improves the detection accuracy of methane TDLAS system and reduces Hardware cost.This paper provides a certain experimental basis for real-time detection of mine CH4 gas,and has certain reference significance for the commercialization of mine TDLAS gas detection system.