Fuel-Rich Combustion of Methane/Air Mixtures at Elevated Pressure:Optical Flow Reactor and Diagnostics

摘要

Non-catalytic partial oxidation of fuel-rich (Φ = 3 to 5) methane/air mixtures at elevated pressure (8 to 20 bar) is beingstudied as a possible means of generating molecular hydrogen. Previous studies using a stainless steel flow reactor havedemonstrated that these mixtures can indeed be ignited and stabilized. Current work is focused on obtaining an increasedunderstanding of the reaction zone and chemical contributions. This testing is being done using an optically accessible flowreactor designed to withstand the harsh combustion environment and allow maximum optical access. Initial experimentsconducted with this flow reactor indicated the presence of a faint blue luminescent reaction zone which is visibly presentunder certain chamber conditions. Emission measurements were applied to this luminescent zone which indicated thepresence of electronically excited formaldehyde. Along with single point measurements, axial measurements were conductedand reveal decreasing emission levels as the reaction proceeds from one of limited luminosity to a highly luminous soot zone.The soot zone was characterized be spectrally resolving its emission and determining the temperature along this zone using agray body analysis.