Oscillation characterization of volatile combustion of single coal particles with multi-species optical diagnostic techniques

• Published in: Fuel (Guildford) Vol. 282; p. 118845
• Main Authors: Peng, Jiangbo, Cao, Zhen, Yu, Xin, Qi, Hongliang, Sun, Rui, Yu, Yang, Chang, Guang, Gao, Long, Zhu, Wenkun, Zhang, Zeyue
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.12.2020; Elsevier BV
• Subjects: Algorithms; Bituminous coal; Chemiluminescence; Coal; Combustion; Combustion oscillation; Diagnostic systems; Doppler effect; Dynamic mode decomposition; Gas temperature; Morphology; Optical diagnosis; Oxygen; Post-production processing; Pulverized coal; Red shift; Single particle in a group of pulverized coal particles (SPGCP); Spatial discrimination; Spatial resolution; Volatiles; Combustion oscillation; Optical diagnosis; Dynamic mode decomposition; Single particle in a group of pulverized coal particles (SPGCP)
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2020.118845

•High-speed multi-species optical diagnostic techniques and DMD analysis method are performed.•Continuous and whole volatile combustion process of the same particle is obtained.•The oscillation frequency characteristics of pulverized coal flame were captured.•Both oxygen concentration and particle aggregation have effects on the frequency characteristics. This paper investigated the oscillation characterization of volatile combustion of single coal particles using high-speed OH-PLIF and CH* chemiluminescence, meanwhile advanced data-driven algorithm as post-processing. The measurement region of in-situ 500 Hz OH-PLIF system was set to 53mm × 35 mm with a spatial resolution of ~23 µm per pixel, which was used to capture the continuous and whole volatile combustion process of single particle in a group of pulverized coal particles (SPGCP). A high-volatiles bituminous coal (30 wt%) burned at a gas temperature of 1700 K with oxygen mole fractions in the range of 10%–30%. The morphology of volatile flame and dynamic evolution was obtained. Dynamic mode decomposition (DMD) method can provide a new insight into combustion oscillation of pulverized coal. The oscillation frequency characteristics of pulverized coal flame were captured, and the red-shift phenomenon of dominant frequency with the increase of oxygen concentration was found. The particle aggregation might lead the low-frequency oscillation of pulverized coal combustion. On the contrary, individual or separated particle combustion could generate larger oscillation frequency.