Effects of Unsteady Natural Gas Combustion on NO_x Emissions Produced by a Fluidic Burner

Abstract

Driven by the need for a new generation of low emission energy systems, research has been conducted that explores the possibility of using unsteady burners to yield significant reductions in environmentally harmful emissions, specifically NO and NO₂. Presented here are the results obtained using a small scale fluidic natural gas burner. This fluidic slot burner was operated to measure the effects of: oscillation frequency, from 0 to 60 Hz; the equivalence ratio Math, varied from 0.6 to 1.4; and the burner diffuser angles Math of 30°, 50° and 70°. When the emissions data obtained from these runs were compared to those obtained using a steady state slot nozzle, dramatic reduction in NO_x production was found throughout most of the frequency range. Additionally, a region of significant NO_x reduction was discovered for many test conditions at oscillation frequencies around the 10-15 Hz range. With the burner operating at an equivalence ratio of 1.0, the maximum observed NO_x reductions were 46.5% for Math = 30°, 40.9% for Math = 50° and 46.1% for Math = 70°.

Keywords:

• N0_x
• Unsteady
• Burner
• Experimental