Detection Research On Temperature And Emissivity Of Hydro-carbonic Flame Based On RAW Image

Temperature measurement technology plays a vital role in many aspects such as industry,aerospace,national defense and scientific experiments.The traditional contact temperature measurement method is easy to interfere wirh the measurement object,and the temperature field distribution cannot be obtained.When the temperature of the measured object is too high,it may cause damage to the instrument,which will affect the accuracy of temperature measurement.Aiming at the above problems,according to the theory of thermal radiation and CCD imaging technology,on the basis of CCD camera flame temperature detection technology based on image processing,the radiation characteristics of hydrocarbon flame were studied,and a determination method of hydrocarbon flame gray body characteristics was put forward.Firstly,the theory of thermal radiation and the principle of CCD camera temperature measurement are introduced in detail to prepare for the simulation calculation and the experiment of hydrocarbon flame;Then,the influence of the two representative wavelengths on the accuracy of temperature calculation are simulated.The results show that the temperature error of the corresponding peak wavelength of the CCD spectral response curve is smaller than that of the CIE specified wavelength as the representative wavelength.Based on the principle of temperature measurement by colorimetric method,the temperature error calculated by RG combination is the smallest among three different combinations of RG,RB and GB with three primary color values;Finally,the flame temperature detection system of CCD camera is introduced in detail,and the calibration experiment of CCD camera is carried out,and the polynomial function relationship between the three primary color values of flame image and the monochromatic radiation intensity is obtained.Aiming at determining whether it is a gray body when calculating the temperature of the hydrocarbon flame by the colorimetric method,a method of determining radiation characteristics based on image processing is proposed,which is verified by candle flame.The temperature of candle flame,the emissivity under three primary color values,and the mean square error of three emissivity are calculated and the radiation characteristics are determined.The experimental results showed that the mean square error of the emissivity was all greater than 0.024,which indicated that the candle flame was a non-gray body.The radiation intensity of the candle flame is corrected by the inverse Abel transformation and the temperature distribution of the candle flame is calculated.