Correlation Spectrum Technology With Multivariate Optical Computing For Gas Monitoring

Global warming and meteorological disasters are increasingly serious and frequent.Real time detection of emissions and concentration changes of polluting gases is an important means to monitor their leakage,implement carbon budget,and assess carbon peaking and carbon neutrality.This thesis takes methane as the monitoring object and explores the feasibility of using non-dispersive infrared absorption spectroscopy correlation technology to develop high-precision and low-cost real-time detection equipment for polluting gases.It has important research significance and development value.Firstly,introduce commonly used gas concentration detection technologies and analyze their advantages and disadvantages,the research status and development trends of Gas Filter Correlation(GFC)and Multivariate Optical Computing(MOC)correlation spectroscopy technologies are mainly introduced.Explain the working principle and composition of gas filter correlation and multivariate optical computing correlation spectral detection systems,compared to the reference gas pool used in gas filter correlation spectral detection system,the multivariate optical element used in multivariate optical computing correlation spectral detection system is compact,which has the advantages of reducing system volume and improving system stability.Then,according to the ideal gas equation,the methane concentration in the reference gas pool is determined,and the gas filter correlation spectral detection system model is built.Introduce the optimization design method for multivariable optical element,successfully design a MOE filter with a thickness of 3 μm and build a model for multivariable optical computing correlation spectral detection system.Simulation studies were conducted on two systems,the simulation results showed that the performance of the two systems in methane concentration detection sensitivity is equivalent.However,the concentration inversion relative error of the multivariate optical computing correlation spectral detection system is low,and the response speed is fast,which has huge advantages in gas concentration monitoring.Finally,a principle verification experiment based on the multivariate optical computing correlation spectral technology was conducted.By developing the designed MOE filter,a principle verification device for multivariate optical calculation gas monitoring correlation spectroscopy technology has been built.The experimental results show that the principle validation device can effectively measure gas concentration,proving that multivariate optical computing correlation spectral technology is feasible and effective for real-time high-precision quantitative monitoring of gases.This thesis studies and provides in the optimization design method for the multivariable optical element,verifies the effectiveness of multivariable optical computing correlation spectral detection system in measuring methane gas concentration.Successfully develops the multivariable optical element,builds a multivariable optical computing gas monitoring correlation spectral technology principle verification device and conducts experiments.Laying the technical foundation for developing high-performance,low-cost,low-power,and strong applicability gas quantitative monitoring instruments.