Research On Imaging Remote Sensing Monitoring Technology For Ship Polluted Gas Emissions

Pollutant gas emissions from industrial and ship exhaust has long been an important factor in causing atmospheric pollution.Polluted gases are prone to be oxidized to form acidic salt aerosols or acid mist,and oxidation produces acid rain,which seriously affects human health while disrupting the balance of the atmospheric ecological environment.However,in actual measurement of the pollutant gas emissions from ship,it is necessary to overcome the low concentration of polluting gases,and the absorption signal of polluting gases is seriously absorbed by water vapor Environmental and technical challenges such as the long detection distance between the detector and ship exhaust gas.However,existing optical remote sensing monitoring technologies,such as laser radar technology,Fourier transform infrared absorption spectroscopy technology,photoacoustic spectroscopy detection technology,ultraviolet differential absorption spectroscopy technology,and spectral imaging technology,are difficult to meet the requirements of ship gas detection for applications such as high space-time resolution and portable computers.In recent years,a new type of optical remote sensing technology for monitoring polluted gases,optical imaging remote sensing monitoring technology,has developed rapidly.This technology has obvious technical advantages in terms of spatial and temporal resolution,detection sensitivity,and detection accuracy.It can real-time and online reproduce the two-dimensional distribution of target gas concentration in space,providing visual monitoring results,and plays an important role in the detection of environmental pollution gases.This paper carries out researches based on the optical imaging technology,which focuses on the theoretical and experimental research on pollutant gases,the theoretical and experimental research on carbon black particles,the application of optical imaging systems to ship exhaust monitoring,and the performance evaluation of system instruments.(1)Aiming at the irregularity of gas shape,the dispersion of traditional spectral technology monitoring data,and the problem of single point detection,imaging remote sensing can be used to detect gas concentration information at any point in space.Combining the atmospheric radiation transmission model and the narrowband window of the narrowband filter,the spectral band selection of SO2 and NO2 was carried out;The theoretical model of ultraviolet imaging remote sensing monitoring technology is established,and the calibration methods of calibration cells and DOAS are introduced and compared;The effects of different incident angles on the central wavelength and transmittance curve of the filter are discussed;The influence of real-time changing solar zenith angle on SO2 calibration curve is analyzed,and the necessity of real-time calibration of SO2 calibration curve is clarified.(2)In order to verify the feasibility of the optical imaging remote sensing monitoring technology scheme,an optical imaging remote sensing detection system was developed and confirmatory experiments were conducted.Aiming at the measurement effect of SO2 gas doped with NO2 gas in ship exhaust,a combination of ultraviolet imaging and DOAS was proposed.Through theoretical method simulation calculations,the impact of different concentrations of SO2 and NO2 gas in ultraviolet imaging methods on SO2 concentration measurement error was analyzed.Experiments were conducted on industrial chimney exhaust,and it was found that correcting NO2 and particulate matter simultaneously reduced the error by 11.3%compared to correcting particulate matter only;Finally,the theoretical model simulation calculation of distance correction is carried out,and the distance correction results are obtained through actual measurement.(3)An optical imaging method was proposed for remote sensing monitoring of carbon black,and the equivalent attenuation cross section curves of particles with different sizes,variances,and complex refractive indices were calculated based on theory;The spectral signal of industrial chimney exhaust gas obtained through a spectrometer is analyzed and compared with the equivalent attenuation cross-section calculated theoretically to determine the equivalent attenuation cross-section.The concentration of NO2 and carbon black in the industrial chimney is obtained through optical imaging and spectroscopy.(4)The remote sensing monitoring of ship exhaust gas has been applied to different types of ships far and near.Aiming at factors such as the uncontrollability of the detected target,weather,and environment,rapid and real-time reverse rendering of the relationship curve between the concentration and emission rate of ship exhaust gas over time has been achieved.The gas detection limit and error are analyzed;The experimental results show that ultraviolet imaging technology has a great application prospect in monitoring the emission of factory chimneys and ship pollution exhaust.