Use of response surface methodology to optimize NOx emissions and efficiency of W-type regenerative radiant tube burner under plasma-assisted combustion

Abstract To address the challenges involved in industrial energy efficiency improvement and tightening of emission requirements, we have made efforts in areas of both design and technology toward the development of a W-type regenerative radiant tube burner that can be adapted to heat treatment furnaces. This design comprises several features of air staging, air swirling, and plasma-assisted combustion technology to improve performance and minimize NOx emissions. Using response surface methodology (RSM), an optimal experimental design was adopted and resulting data was subjected to analysis of variance (ANOVA) to examine the significance of the operating parameters, including excess air ratio and switching time. Interactions between variables were statistically validated. The results illustrate that the radiant tube can significantly reduce the temperature deviation and induce uniform temperature distribution on the furnace wall. ANOVA analysis showed that the process, properly represented by a second-order polynomial model, was significant (p