濃淡燃焼におけるNO_x, CO生成特性  [in Japanese] NO_x and CO Formation Characteristics in Rich-Lean Combustion  [in Japanese]

NO_x and CO formation characteristics in rich-lean flames at a multi-slit burner were studied experimentally and numerically. In the rich-lean combustion, rich and lean slit burners are set side by side. The overall NO_x and CO concentrations were measured by using a water-cooled quartz microprobe to investigate the effect of various pairs of air ratios for the rich and lean flames. To understand the NO_x formation mechanism, two-dimensional reactive flow calculations were also performed. The results suggest that the thermal and prompt NO in the rich flames are the main source of NO_x production, and NO_x increases when the rich flames air ratio becomes lower or the fuel flow rate ratio for the rich burners increases. It is also found that the burner plate thickness affects the blow-off limits of the burner. These results are useful for improving the low pollutant and stable combustion method.