INVESTIGATION OF DESIGN PARAMETERS INFLUENCING THE PERFORMANCE OF PREMIXED SURFACE BURNERS

摘要

Compared to diffusion and partially premixed burners, fully premixed burners have the advantage of low NOx emissions. On the other hand, fully premixed combustion is sensitive toward flame instabilities, i.e., flashback, blow-off, and acoustical emissions. These instabilities limit the power modulation of a burner, thus decreasing its application range on the market. The scope of this investigation is the performance of fully premixed gas burners with a perforated surface pattern (i.e., a slits and/or holes pattern), focusing on the influences of burner surface pattern design and burner shape on burner operation. Experiments showed that the surface pattern design strongly influences the burner power modulation range and the emission of pollutants. Visualization and numerical simulation of the cold flow through a perforated surface pattern indicate that the dimensions of the flow recirculation zone in the vicinity of the slits/holes outlet are responsible for flame stabilization. Redesign of the burner surface pattern could lead to a better flow distribution through the burner and an improved power modulation range.