Research on Flame Temperature Measurement Based on CH Emission Spectrum

To address the demand and challenges for flame temperature measurement in field of combustion diagnostic, the paper conducts research on temperature measurement technology based on emission spectrum. Firstly, the relationship between emission spectral intensity and vibrational temperature, rotational temperature was introduced theoretically. Based on this, the simulation of CH emission spectrum was completed. After-wards, CH emission spectra of ethylene-air premixed flame under three different working conditions were measured experimentally, and the simulated spectra were fitted to the measured spectra using the least-squares fitting method to obtain temperature measurement results of the flame under three different working conditions. Finally, the average of temperature measurement results from emission spectra and the measurement result by thermocouple under the same working condition were compared, demonstrating that the relative errors between the two were less than 10% across all three working conditions, and the relative standard deviation of temperature measurement results by emission spectra within the same working condition was less than 1%, thereby verifying the applicability of the temperature measurement method based on emission spectrum in field of combustion diagnostic.