Recessed fuel injector positioning

A method for operating a combustion chamber, the method comprising

• injecting a fuel into an inner volume of the combustion chamber by a fuel injector comprising a fuel outlet,
• wherein the combustion chamber comprises a pilot burner device comprising a pilot body with a pilot surface which is exposable to a flame in the inner volume of the combustion chamber and a recess comprising a base area spaced from a section of the pilot surface surrounding the recess and a lateral surface that connects the base area to the pilot surface,
• igniting the fuel inside the inner volume by an ignitor unit,
• wherein the ignitor unit is arranged at the pilot surface such that fuel which passes the ignitor unit is ignitable,
• wherein the fuel outlet is formed for directing the fuel in the direction to the ignitor unit,
• wherein the fuel outlet is arranged inside the recess,
• wherein the ignitor unit is located outside of the recess, and
• directing an air blast into the inner volume of the combustion chamber by an air blast injector located in the recess and comprising an air blast outlet arranged at the pilot surface or at the base area and arranged circumferentially adjacent to the fuel outlet with respect to a circumferential direction of the combustion chamber, wherein the air blast injector is configured to direct the air blast in the circumferential direction toward the fuel outlet and then the ignitor unit, which is effective to direct the fuel to the ignitor unit.

A combustion chamber for a gas turbine, the combustion chamber comprising

• a pilot burner device comprising a pilot body with a pilot surface which is facing an inner volume of the combustion chamber, wherein the pilot burner device further comprises a centre axis,
• a fuel injector comprising a fuel outlet for injecting a fuel into the inner volume,
• an ignitor unit for igniting the fuel inside the inner volume,
• wherein the ignitor unit is arranged at the pilot surface such that fuel which passes the ignitor unit is ignitable,
• wherein the pilot body comprises a recess comprising a base area spaced from a section of the pilot surface surrounding the recess and a lateral surface that connects the base area to the pilot surface, wherein the fuel outlet is arranged within the recess, and wherein the recess is located off-centred from the centre axis, and
• an air blast injector for injecting an air blast into the inner volume,
• wherein the ignitor unit is located in the recess,
• wherein the air blast injector comprises an air blast outlet which is arranged outside of the recess and arranged circumferentially adjacent to the fuel outlet with respect to a circumferential direction of the combustion chamber, and wherein the air blast injector is configured to direct the air blast in the circumferential direction toward the fuel outlet and then the ignitor unit, which is effective to direct the fuel to the ignitor unit.