Experimental Study on OH*, CH*, and CO2* Chemiluminescence Diagnosis of CH4/O2 Diffusion Flame with CO2-Diluted Fuel

Xinming Tian; Jiabao Yang; Yan Gong; Qinghua Guo; Xingjun Wang; Guangsuo Yu

doi:10.1021/acsomega.2c04689

Experimental Study on OH, CH, and CO₂* Chemiluminescence Diagnosis of CH₄/O₂ Diffusion Flame with CO₂-Diluted Fuel

ACS Omega. 2022 Oct 31;7(45):41137-41146. doi: 10.1021/acsomega.2c04689. eCollection 2022 Nov 15.

Authors

Xinming Tian¹, Jiabao Yang¹, Yan Gong¹, Qinghua Guo¹, Xingjun Wang¹, Guangsuo Yu^{1

2}

Affiliations

¹ Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai200237, P.R. China.
² State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, Ningxia University, Yinchuan, Ningxia750021, P.R. China.

Abstract

OH* and CH* chemiluminescence in hydrocarbon flames are often applied to characterize flame structure, equivalence ratio, strain rate, heat release rate, etc. In this study, chemiluminescence images of OH*, CH*, and CO₂* in the CH₄/O₂ diffusion flame were obtained using a CCD camera imaging system. The effect of CO₂ dilution on the flame structure, strain rate, and other flame characteristics of CH₄/O₂ diffusion flame was discussed. The results show that CO₂ dilution greatly affects flame morphology and chemiluminescence intensity. There are quantitative functions between the chemiluminescence peak intensity of OH* and CH* and the CO₂ dilution level. The CO₂* average intensity in the flame zone is better suited to characterize the dilution level than the CO₂* peak intensity. Moreover, the strain rate of CO₂-diluted laminar flame is defined. It is found that there is a linear relationship between the thickness of the OH* reaction zone and the square root of the strain rate.