METHOD OF BURNING FUEL AND A BOILER

The invention relates to a method of burning fuel, wherein the method comprises supplying fuel and combustion air into a boiler furnace(1)through a set of burners (3) located at or about a certain horizontal burner level (4). The flame of each of the burners is stabilized by providing the fuel feed pipe (5) with a flame stabilizing ring (7).The method further comprises setting the air coefficient (SRwing )of each of the wing burners (9) at 0.95 or above, and the air coefficient (SRcenter) of the at least one center burner (8) at 0.9 or below; setting the swirl number (Swing ) of the secondary air supplied through each of the wing burners (9) at 0 -0.3; and broadening the shape of the flame of the at least one center burner (8) by producing an outer recirculation zone around the inner recirculation zone produced downstream of the flame stabilizing ring (7).The invention further relates to a boiler.