Experimental and modeling analysis of laminar flame speed over the pyrolytic gas from red pinewood

Abstract

In combustion research, the laminar flame speed (SL) is an important basis for the study of fuel combustion and mechanism verification. A large number of studies have been done on various combustibles, mostly focusing on gas and liquid combustibles, but less on solid combustibles, and the SL of solid combustibles cannot be measured directly and effectively by conventional methods. This paper uses red pine wood as the object of study, analyses the pyrolysis gas components after high-temperature pyrolysis, and uses the Bunsen burner experimental system to study the SL of pyrolysis gas, and obtains the laminar flame speed (SL) of the gas-phase flame when burning red pine wood, which has certain guiding significance for the study of the laminar flame speed (SL) of solid combustibles. In this paper, firstly, the pyrolysis gas products of red pine wood were analyzed by TG-DSC as well as GC/MS, and it was found that the direct reaction was the most violent at 210°C–410 °C, and the reaction rate gradually levelled off after 410 °C. It was also found that the gas mainly consisted of H2, CO2, C2H4, CO, CH4, C2H6, C3H6 and C3H8, accounting for more than 98%, and with the pyrolysis Secondly, the laminar flame speed (SL) of the gas products was investigated using the Bunsen burner, and it was found that the laminar flame speed (SL) of the pyrolysis gases gradually increased with the increase of the pyrolysis temperature, with 15.7 cm-s−1, 32.94 cm-s−1 and 36.89 cm-s−1 for the pyrolysis gases at 350 °C, 450 °C and 550 °C, respectively Finally, numerical simulations were carried out to investigate the effects of initial temperature and altitude induced changes in air pressure and oxygen concentration on the laminar flame speed of the gas products, and it was found that the laminar flame speed of pyrolysis gases gradually increased with increasing initial temperature and decreased with increasing altitude. The effect of hydrocarbon gases on the SL-max of CH4 is essentially linear in the concentration range of 40%, while the effect of H2, CO and CO2 is essentially in the quadratic polynomial distribution.