Method for operating a gas turbine burner with a swirl generator

A method for operating a burner having a swirl generator defined by at least two walls facing one another to define a substantially conical swirl chamber, the swirl generator including swirl generator nozzles arranged to inject fuel and apertures arranged to feed an oxidizer into said swirl chamber, a mixing tube positioned downstream of the swirl generator, and a lance positioned inside at least the swirl generator, the lance extending along a longitudinal axis of the swirl generator and being provided with lance side nozzles for ejecting fuel within the burner, the lance side nozzles having axes inclined with respect to an axis of the lance, wherein the lance includes an annular protrusion extending from and encircling an outer surface of a body of the lance, the method comprising:

• during operation with oil fuel:
• at starting, injecting about 80% of the oil fuel through a lance tip nozzle and injecting about 20% of the oil fuel through the lance side nozzles;
• at idle operation, injecting about 75% of the oil fuel through the lance tip nozzle and injecting about 25% of the oil fuel through the lance side nozzles;
• at part load, injecting about 50% of the oil fuel through the lance tip nozzle and injecting about 50% of the oil fuel through the lance side nozzles;
• at full load, injecting about 10% of the oil fuel through the lance tip nozzle and injecting about 90% of the oil fuel through the lance side nozzles;
• and,
• wherein the oil fuel injected through the lance side nozzles is injected against the annular protrusion as the oil fuel exits the lance side nozzles;
• and,
• during operation with gaseous fuel:
• at starting, injecting about 70-80% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 0-10% of the gaseous fuel through the swirl generator nozzles;
• at idle operation, injecting about 70% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 10% of the gaseous fuel through the swirl generator nozzles;
• at part load, injecting about 40% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 40% of the gaseous fuel through the swirl generator nozzles;
• and
• at full load, injecting about 5% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 15% of the gaseous fuel through the swirl generator nozzles;
• wherein the gaseous fuel injected through the lance side nozzles is injected against the annular protrusion as the gaseous fuel exits the lance side nozzles.

A method for operating a burner having a swirl generator defined by at least two walls facing one another to define a substantially conical swirl chamber, the swirl generator including swirl generator nozzles arranged to inject fuel and apertures arranged to feed an oxidizer into said swirl chamber, a mixing tube positioned downstream of the swirl generator, and a lance positioned inside at least the swirl generator, the lance extending along a longitudinal axis of the swirl generator and being provided with lance side nozzles for ejecting fuel within the burner, the lance side nozzles having axes inclined with respect to an axis of the lance, wherein the lance includes an inner surface of a lid encircling a body of the lance, and the lance side nozzles are disposed at an acute angle with respect to the longitudinal axis of the lance, the method comprising:

• during operation with oil fuel:
• at starting, injecting about 80% of the oil fuel through a lance tip nozzle and injecting about 20% of the oil fuel through the lance side nozzles;
• at idle operation, injecting about 75% of the oil fuel through the lance tip nozzle and injecting about 25% of the oil fuel through the lance side nozzles;
• at part load, injecting about 50% of the oil fuel through the lance tip nozzle and injecting about 50% of the oil fuel through the lance side nozzles;
• at full load, injecting about 10% of the oil fuel through the lance tip nozzle and injecting about 90% of the oil fuel through the lance side nozzles;
• and,
• generating a cylindrical fuel film encircling the lance via the oil fuel injected from the lance side nozzles;
• wherein the oil fuel injected through the lance side nozzles is injected against the inner surface of the lid;
• and,
• during operation with gaseous fuel:
• at starting, injecting about 70-80% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 0-10% of the gaseous fuel through the swirl generator nozzles;
• at idle operation, injecting about 70% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 10% of the gaseous fuel through the swirl generator nozzles;
• at part load, injecting about 40% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 40% of the gaseous fuel through the swirl generator nozzles;
• and
• at full load, injecting about 5% of the gaseous fuel through the lance tip nozzle, injecting about 20% of the gaseous fuel through the lance side nozzles, and injecting about 15% of the gaseous fuel through the swirl generator nozzles;
• wherein the gaseous fuel injected through the lance side nozzles is injected against the inner surface of the lid.