Experimental and numerical investigation of flame speed retardation by water mist

In this paper, polycyclic aromatic hydrocarbons (PAHs) and soot formation in rich partially premixed flames and nonpremixed flames were studied using a blend of n-heptane and toluene. The flames were diluted with Ar, N2, and CO2 to control the flame temperature. Laser-induced fluorescence, laser-induced incandescence, and two-color pyrometry were used to study the effects of flame temperature on the PAHs and soot evolution. Results show that temperature distributions are similar for different gas dilutions at low flow rates. However, the higherature area increases dramatically in size at high flow rates and it depends on diluents in the order Ar > N2 > CO2 with regard to flame temperature. With an increase in the flow rate of Ar, the higher growth rate of flame temperature and bigger region of higherature region can lead to a higher growth rate from small to large PAHs and higher soot volume fraction. However, for CO2 dilution, the increased flow rate results in the increase of formation of large PAHs, but soot formation is reduced due to the fact that lower flame temperature suppresses the soot formation. Therefore, it can be concluded that the evolution of PAHs and soot strongly depends on flame temperature. (Less)

Effects of Flame Temperature on PAHs and Soot Evolution in Partially Premixed and Diffusion Flames of a Diesel Surrogate

Suppressing methane explosion overpressure using a charged water mist containing a NaCl additive

Pressure effects on real-gas laminar counterflow

Effect of charcoal type on the formation of polycyclic aromatic hydrocarbons in grilled meats

Extinguishment of counterflow methane/air diffusion flame by polydisperse fine water droplets

Benzene pyrolysis and PM formation study using a flow reactor

Oxygen effect on PAH and PM formation in low temperature benzene pyrolysis

Nano meter size particulate matter (PM) formed by the combustion process of hydrocarbon fuel has harmful effects on human health. Fundamental research works for investigation of formation behavior of PM precursor such as polycyclic aromatic hydrocarbons (PAHs) in combustion process were required for the reduction of nano-PM emission. In this study, PM and PAH formed by low temperature (less than 1350K) pyrolysis and oxidation of hydrocarbon fuel using a flow reactor were investigated. The mass concentration of PM was obtained by the filter sampling method with a glass-fiber filter, while the mass concentration of PAH was analyzed by a Gas Chromatography. In addition, numerical simulation for PAH formation was performed using a CHEMKIN-Pro software. As a result, it was found that the mass concentration of PM increased with temperature raise under various equivalent ratio conditions (φ = ∞, 6.2 and 2.8). Therefore, it was also found that the mass concentration of PM without oxidation condition was higher than that with oxidation condition. 

Koki Kashiwa

Papers

Extinguishment of counterflow methane/air diffusion flame by polydisperse fine water droplets

Benzene pyrolysis and PM formation study using a flow reactor

Oxygen effect on PAH and PM formation in low temperature benzene pyrolysis

PAHs and PM formed by low temperature pyrolysis and oxidation of hydrocarbon fuel