Effects of CO2-H2O dilution on the characteristics of CH4-air-O2 flames

International audience Study of non-premixed turbulent flames stabilized by a swirler Control of pollutant emissions / emissions standards Improve performances of combustion plants Investigations on flame characteristics Effects of oxygen enrichment Effects of steam and CO2 dilution Effects of swirl intensit

Numerical analysis of characteristics of biogas and syngas combustion

International audienceDevelopment of modular adapted energy concept- Gasifier - multi-fuel burner - boilerCharacterization of syngas and biogas flames - Experimentally: stability, pollutant emissions, temperature - Numerically: Calculations of laminar burning velocity, flame temperature, pollutants (NOx, CO)…This poster: some results of calculation

Oxygen enrichment effects on CH 4 -air turbulent flow characteristics in a coaxial swirl burner

International audienceThis paper reports results on the effect of oxygen enrichment on flow and turbulent flames in a coaxial swirl burner. The investigation was performed by S-PIV in CH4-air-O2 non-reacting and reacting flows. This work is the continuation of studies carried out previously by the authors on the same burner, with different new operating conditions. The burner consists of 2 concentric tubes, with a swirler located in the annular part through which the oxidant (air-O2) is supplied. The CH4 gas is delivered into the central tube and injected radially into the combustion chamber through small holes. The burner is placed in a parallelepiped combustion chamber with a volume of 120×50×50 cm3. The paper reports detailed results on mean velocity fields, profiles of the three velocity components (U,V,W) and velocity fluctuations (U’,V’,W’) in the case of a 150 Nl/min oxidant flow rate, a swirl number Sn = 1.4 and an equivalence ratio Φ = 1. Three cases of O2 addition were investigated, 21%, 25%, and 30% (in vol.) corresponding to 9.4 kW, 11.7 kW, and 14.5 kW of combustion power, respectively. In-depth analysis of the field velocity differences between reactive and non-reactive cases was carried out and showed a significant difference in flow velocities between reacting and non-reacting flows. The profiles of the mean velocities, fluctuations and velocity decays differed, and higher values were observed in the reacting case. The enrichment of air with oxygen affected the velocity fields and their fluctuations in both distribution and values. The addition of O2 increased the flame temperature, leading to a greater radial expansion and a reduction in the size of the recirculation zone. The maximum axial velocity increased significantly as a function of the O2 rate, whereas the swirling velocity varied only slightly. The velocity fluctuation results also revealed a difference in profiles and values depending on O2 enrichments and locations along the flow

Effects of CO2-H2O dilution on the characteristics of CH4-air-O2 flames

International audienceStudy of non-premixed turbulent flames stabilized by a swirler Control of pollutant emissions / emissions standards Improve performances of combustion plants Investigations on flame characteristics Effects of oxygen enrichment Effects of steam and CO2 dilution Effects of swirl intensit

Experimental Study of EGR Dilution and O 2 Enrichment Effects on Turbulent Non-Premixed Swirling Flames

International audienc

Experimental Study of EGR Dilution and O 2 Enrichment Effects on Turbulent Non-premixed Swirling Flames

International audienc

Effects of CO 2 Dilution and O 2 Enrichment on Non-premixed Turbulent CH 4 -Air Flames in a Swirl Burner

International audienceKeywords:Effects of oxygen enrichment and CO2 dilution on the characteristics of non-premixed methane-air turbulent flames in a coaxial swirl burner are investigated in this article. The work primarily focuses on pollutant emissions (NOx and CO), flame structure, and stability investigations. The experiments are conducted using a 1-m high, 0.5-m wide, 25-kW parallelepiped combustion chamber, cooled by outside water. The burner configuration consists of two concentric tubes in which a swirler is placed inside the annular part for air or air-O2-CO2 supply that can allow for the rotation of the oxidant. Fuel is injected radially from the central tube. OH* chemiluminescence measurements are performed to describe the structure and stability of the flame providing information on the flame lengths and lift-off heights. The measurements are conducted with the oxygen concentrations ranging from 21% to 35%, CO2 concentrations ranging from 0 to 20%, swirl numbers ranging from 0.8 to 1.4, and global equivalence ratios ranging from 0.8 to 1. The lift-off heights, the fluctuations of the flame base, and the flame lengths are determined as a function of these parameters. The results show that oxygen enrichment stabilizes better the flame, promotes the formation of NOX and CO2, and decreases the formation of CO. The dilution by CO2 changes significantly the flame shape and its behavior. The flame becomes longer, less intense, and unstable. CO2 dilution reduces considerably the flame temperature which obviously reduces the NOx formation, but it is observed that CO2 and CO concentrations in the flue gases are increased