초록

A lean premix burner for a gas turbine having at least one fuel supply ring 4 fitted with primary fuel nozzles 8 and additional secondary fuel nozzles 9, and a method of operation for this lean premix burner.

대표청구항 ▼

1. A lean premix burner for a gas turbine, comprising:at least one fuel supply ring, a circumference of the fuel supply ring having a plurality of uniformly sized sectors, the fuel supply ring including: a plurality of primary fuel nozzles, all of which are distributed evenly along the circumference

1. A lean premix burner for a gas turbine, comprising:at least one fuel supply ring, a circumference of the fuel supply ring having a plurality of uniformly sized sectors, the fuel supply ring including: a plurality of primary fuel nozzles, all of which are distributed evenly along the circumference of the fuel supply ring, and a plurality of additional secondary fuel nozzles distributed unevenly along the circumference of the fuel supply ring, wherein at least some of the sectors include only primary fuel nozzles and at least some of the remaining sectors include both primary fuel nozzles and secondary fuel nozzles. 2. A lean premix burner according to claim 1, wherein the fuel supply ring further comprises a plurality of fuel mini-nozzles.3. A lean premix burner according to claim 2, wherein the fuel mini-nozzles are arranged in clusters.4. A lean premix burner according to claim 3, wherein the fuel supply ring is constructed and arranged to generate richer air-fuel mixture by activation of least one the secondary fuel nozzles and the fuel mini-nozzles.5. A lean premix burner according to claim 4, wherein the sectors are quadrants and the secondary fuel nozzles are positioned in only some of the quadrants.6. A lean premix burner according to claim 1, wherein the sectors are quadrants and the secondary fuel nozzles are positioned in only some of the quadrants.7. A method of operation of a lean premix burner for a gas turbine comprising at least one fuel supply ring including a plurality of primary fuel nozzles and a plurality of additional secondary fuel nozzles, the method comprising:at low gas turbine load levels, enriching an air-fuel mixture locally at certain sectors around the fuel supply ring, providing fuel injection through the primary fuel nozzles in some sectors and stopping fuel injection through the primary fuel nozzles at other sectors around the fuel supply ring, while maintaining a total fuel mass flow to the lean premix burner essentially the same. 8. A method according to claim 7, and further comprising:switching on at least secondary fuel nozzles adjacent to primary fuel nozzles at low gas turbine load levels to provide a locally enriched fuel-air mixture. 9. A method according to claim 8, and further comprising:switching off primary fuel nozzles not arranged adjacent the secondary fuel nozzles. 10. A method according to claim 9, and further comprising:locally supplying a richer fuel-air mixture through additional fuel mini-nozzles when the gas turbine load decreases further. 11. A method according to claim 10, and further comprising: staging the primary fuel nozzles, secondary fuel nozzles and fuel mini-nozzles in operation in local clusters along a circumference of the fuel supply ring.12. A method according to claim 7, and further comprising:switching off primary fuel nozzles not arranged adjacent the secondary fuel nozzles. 13. A method according to claim 12, and further comprising:locally supplying a richer fuel-air mixture through additional fuel mini-nozzles when the gas turbine load decreases further. 14. A method according to claim 13, and further comprising: staging the primary fuel nozzles, secondary fuel nozzles and fuel mini-nozzles in operation in local clusters along a circumference of the fuel supply ring.15. A method according to claim 7, and further comprising:locally supplying a richer fuel-air mixture through additional fuel mini-nozzles when the gas turbine load decreases further. 16. A method according to claim 15, and further comprising: staging the primary fuel nozzles, secondary fuel nozzles and fuel mini-nozzles in operation in local clusters along a circumference of the fuel supply ring.17. A lean premix burner for a gas turbine, comprising:at least one fuel supply ring including: a plurality of primary fuel nozzles, a plurality of additional secondary fuel nozzles, and a plurality of fuel mini-nozzles arranged in clusters along a circumference of the fuel supply ring such that the fuel mini-nozzles are distributed unevenly along the circumference of the fuel supply ring. 18. A lean premix burner according to claim 17, wherein the primary fuel nozzles are evenly distributed along circumference fuel supply ring and the secondary fuel nozzles are distributed unevenly along the circumference of the fuel supply ring.19. A lean premix burner according to claim 18, wherein the secondary fuel nozzles are positioned in only some sectors of the fuel supply ring.20. A lean premix burner according to claim 19, wherein the sectors are quadrants and the secondary fuel nozzles are positioned in only some of the quadrants.21. A lean premix burner according to claim 20, wherein the fuel supply ring is constructed and arranged to generate a richer air-fuel mixture by activation of at least one of the secondary fuel nozzles and the fuel mini-nozzles.22. A lean premix burner according to claim 17, wherein the secondary fuel nozzles are positioned in only some quadrants of the fuel supply ring.