Effects of swirl premixed flame interaction on NOx emission in a gas turbine combustor with multi-burners

Abstract

Effects of burner interactions on NOx emission are investigated numerically by focusing on changes in swirl flow patterns between burners in a gas turbine combustor. Based on the previous numerical results of two burners with several types, leading to increase in NOx emission compared with a single burner configuration, in this study, the number of burners in increased up to seven with three counter-clockwise and four clockwise burners and the multiple burners are studied numerically. Some of them are ignited by fuel injection, and the others are not. Various configurations are selected depending on the number of ignited burners and their positions. The number is variable from three to seven for calculation of NOx emission. As the number increases from three to seven, the equivalence ratio grows linearly to 0.49 with seven-burner ignition. NOx emission is calculated at the exit of the model combustor, and it increases with the number of ignited burners. A nonlinear increase in NOx emission is observed, growing slowly with the small number and rapidly with more burners. Flame interaction between multi-burners intensifies as the number of ignited burners increases from 3 to 7, leading to a nonlinear increase in NOx emission with the number of ignited burners.