Fuel lance for a gas turbine installation and a method for operating a fuel lance

1. A fuel lance for a gas turbine installation with sequential combustion, in which hot gas is produced in a first combustion chamber and expanded in a subsequent turbine, and then flows through a subsequent second combustion chamber in which the fuel lance is arranged for injecting fuel into the hot gas, the fuel lance comprises a lance section which extends in a flow direction of the hot gas and includes at least an outer tube which is arranged concentrically to a lance axis, and a center tube which is concentrically arranged in the outer tube and in which the fuel is guided to a lance tip to be injected from a region of the lance tip through first injection openings on the lance tip into the hot gas, the center tube terminates at a distance from the lance tip and includes an opening at an end thereof which corresponds to a width of the center tube, a chamber is defined between the opening of the center tube and the lance tip, the chamber is delimited by the opening of the center tube and outer tube, the first injection openings are oriented so that the fuel jets which emerge from them form an acute angle with the lance axis.

2. The fuel lance as claimed in claim 1 , wherein the lance tip is rounded, and the first injection openings are arranged in a region of the rounding.

3. A fuel lance for a gas turbine installation with sequential combustion, in which hot gas is produced in a first combustion chamber and expanded in a subsequent turbine, and then flows through a subsequent second combustion chamber in which the fuel lance is arranged for injecting fuel into the hot gas, the fuel lance comprises a lance section which extends in a flow direction of the hot gas and includes at least an outer tube which is arranged concentrically to a lance axis, and a center tube which is concentrically arranged in the outer tube and in which the fuel is guided to a lance tip to be injected from a region of the lance tip through first injection openings on the lance tip into the hot gas, the first injection openings are oriented so that the fuel jets which emerge from them form an acute angle with the lance axis, wherein an inner tube is concentrically arranged in the center tube, the inner tube is guided towards the lance tip, and second injection openings for injecting liquid fuel supplied through the inner tube are provided on the lance tip.

4. The fuel lance as claimed in claim 3 , wherein the first and second injection openings are arranged in each case on a common radius around the lance axis, and a radius around which the second injection openings are arranged is smaller than a radius around which the first injection openings are arranged.

5. The fuel lance as claimed in 3 , wherein the second injection openings are adapted to create a fuel jet.

6. The fuel lance as claimed in claim 3 , wherein the second injection openings are adapted to create an atomized spray.

7. A method for operating a fuel lance for a gas turbine installation with sequential combustion, in which hot gas is produced in a first combustion chamber and expanded in a subsequent turbine, and then flows through a subsequent second combustion chamber in which the fuel lance is arranged for injecting fuel into the hot gas, the method comprising:

providing the fuel lance having a lance section which extends in a flow direction of the hot gas and includes at least an outer tube which is arranged concentrically to a lance axis, and a center tube which is concentrically arranged in the outer tube and in which the fuel is guided to a lance tip to be injected from a region of the lance tip through first injection openings on the lance tip into the hot gas, the center tube terminates at a distance from the lance tip and includes an opening at an end thereof which corresponds to a width of the center tube, a chamber is defined between the opening of the center tube and the lance tip, the chamber is delimited by the opening of the center tube and outer tube, the first injection openings are oriented so that the fuel jets which emerge from them form an acute angle with the lance axis;

guiding syngas, as fuel, through the center tube and to the first injection openings and injecting the syngas through the first injection openings into the hot gas flow.

8. The method as claimed in claim 7 , further comprising also guiding the syngas in the space between outer tube and center tube to the first injection openings and injecting the syngas through the first injection openings into the hot gas flow.

9. A method for operating a fuel lance for a gas turbine installation with sequential combustion, in which hot gas is produced in a first combustion chamber and expanded in a subsequent turbine, and then flows through a subsequent second combustion chamber in which the fuel lance is arranged for injecting fuel into the hot gas, the method comprising:

providing the fuel lance having a lance section which extends in a flow direction of the hot gas and includes at least an outer tube which is arranged concentrically to a lance axis, and a center tube which is concentrically arranged in the outer tube and in which the fuel is guided to a lance tip to be injected from a region of the lance tip through first injection openings on the lance tip into the hot gas, the first injection openings are oriented so that the fuel jets which emerge from them form an acute angle with the lance axis;

guiding syngas, as fuel, through the center tube and to the first injection openings and injecting the syngas through the first injection openings into the hot gas flow, and

guiding a diluting medium in the space between outer tube and the center tube to the first injection openings and injecting the diluting medium through the first injection openings into the hot gas flow.

10. A method for operating a fuel lance for a gas turbine installation with sequential combustion, in which hot gas is produced in a first combustion chamber and expanded in a subsequent turbine, and then flows through a subsequent second combustion chamber in which the fuel lance is arranged for injecting fuel into the hot gas, the method comprising:

providing the fuel lance having a lance section which extends in a flow direction of the hot gas and includes at least an outer tube which is arranged concentrically to a lance axis, and a center tube which is concentrically arranged in the outer tube and in which the fuel is guided to a lance tip to be injected from a region of the lance tip through first injection openings on the lance tip into the hot gas, the center tube terminates at a distance from the lance tip and includes an opening at an end thereof which corresponds to a width of the center tube, the first injection openings are oriented so that the fuel jets which emerge from them form an acute angle with the lance axis;

guiding syngas, as fuel, through the center tube and to the first injection openings and injecting the syngas through the first injection openings into the hot gas flow; and

guiding air that acts as a carrier or screening medium in the space between outer tube and the center tube to the first injection openings and injecting the air through the first injection openings into the hot gas flow.

11. A method for operating a fuel lance for a gas turbine installation with sequential combustion, in which hot gas is produced in a first combustion chamber and expanded in a subsequent turbine, and then flows through a subsequent second combustion chamber in which the fuel lance is arranged for injecting fuel into the hot gas, the method comprising:

providing the fuel lance having a lance section which extends in a flow direction of the hot gas and includes at least an outer tube which is arranged concentrically to a lance axis, and a center tube which is concentrically arranged in the outer tube and in which the fuel is guided to a lance tip to be injected from a region of the lance tip through first injection openings on the lance tip into the hot gas, the first injection openings are oriented so that the fuel jets which emerge from them form an acute angle with the lance axis;

guiding syngas, as fuel, through the center tube and to the first injection openings and injecting the syngas through the first injection openings into the hot gas flow;

providing an inner tube concentrically arranged in the center tube, the inner tube is guided towards the lance tip, and second injection openings for injecting liquid fuel supplied through the inner tube are provided on the lance tip;

guiding the syngas in the space between center tube and inner tube syngas to the first injection openings and injecting the syngas through the first injection openings into the hot gas flow; and

guiding a liquid fuel in the inner tube to the second injection openings and injecting the liquid fuel through the second injection openings into the hot gas flow.

12. The method as claimed in claim 11 , further comprising guiding syngas in the space between outer tube and center tube to the first injection openings and injecting the syngas through the first injection openings into the hot gas flow.

13. The method as claimed in claim 11 , further comprising guiding a diluting medium in the space between outer tube and the center tube to the first injection openings and injecting the diluting medium through the first injection openings into the hot gas flow.

14. The method as claimed in claim 11 , further comprising air as a carrier or a screening medium in the space between outer tube and the center tube to the first injection openings and injecting the air through the first injection openings into the hot gas flow.

15. The method for operating a fuel lance for a gas turbine installation with sequential combustion, in which hot gas is produced in a first combustion chamber and expanded in a subsequent turbine, and then flows through a subsequent second combustion chamber in which the fuel lance is arranged for injecting fuel into the hot gas, the method comprising:

providing the fuel lance having a lance section which extends in a flow direction of the hot gas and includes at least an outer tube which is arranged concentrically to a lance axis, and a center tube which is concentrically arranged in the outer tube and in which the fuel is guided to a lance tip to be injected from a region of the lance tip through first injection openings on the lance tip into the hot gas, the first injection openings are oriented so that the fuel jets which emerge from them form an acute angle with the lance axis, and an inner tube concentrically arranged in the center tube, the inner tube is guided towards the lance tip, and second injection openings for injecting liquid fuel supplied through the inner tube are provided on the lance tip;

guiding a gas mixture consisting of natural gas and steam or nitrogen, as fuel, in the space between center tube and inner tube to the first injection openings and injecting the fuel through the first injection openings into the hot gas flow; and

guiding a liquid fuel in the inner tube to the second injection openings and injecting the liquid fuel through the second injection openings into the hot gas flow.

16. The method as claimed in claim 15 , further comprising guiding air as a carrier in the space between outer tube and the center tube to the first injection openings and injecting air through the first injection openings into the hot gas flow.