다단 연소기의 예혼합 화염간 거리에 따른 연소 동특성 영향

Abstract

Axial fuel staging is currently receiving attention to enhance the operational and fuel flexibility of gas turbines. We investigate the effects of injector spacing on combustion dynamics in an axially-staged combustor. Self-excited combustion instability measurements were performed under the identical operating conditions with three different spacings (400, 500, and 600 mm) between the primary and secondary flames, along with FEM-based linear acoustic calculations. The results show that L3-coupled instabilities mainly develop, but at a certain secondary injector location (400 mm), the instabilities were sufficiently suppressed.