Combustor with brief quench zone with slots

1. A combustor for combusting a number of flows of air and a number of flows of fuel, comprising:

a central swirler for producing a high swirl quench air flow;

a plurality of trapped vortex cavities surrounding the central swirler for producing a flow of combustion gases, such that an aft end wall of each of the plurality of trapped vortex cavities at least partially overlaps with the central swirler;

a brief severe quench zone comprising a liner with a constricted shape downstream of the plurality of trapped vortex cavities to quench the flow of combustion gases between an outer quench air flow and the high swirl quench air flow, wherein the high swirl quench air flow and the flow of combustion gases are delivered to the constricted shape of the brief severe quench zone, wherein the brief severe quench zone comprises a plurality of slots therein, the plurality of slots comprising a herringbone-like pattern, such that alternating rows of the plurality of slots are positioned in different directions so as to form a V shape; and

an expansion zone downstream of the brief severe quench zone.

2. The combustor of claim 1 , wherein the liner has an expanded shape about the expansion zone.

3. The combustor of claim 1 , wherein the plurality of trapped vortex cavities comprises a plurality of air injectors.

4. The combustor of claim 1 , wherein the plurality of trapped vortex cavities comprises a plurality of fuel injectors.

5. The combustor of claim 4 , wherein the plurality of fuel injectors comprises an aft wall fuel injector or a forward wall fuel injector.

6. The combustor of claim 4 , wherein the plurality of fuel injectors comprises a gas fuel injector and a liquid fuel injector.

7. The combustor of claim 1 , wherein each of the plurality of trapped vortex cavities creates a fuel/air vortex therein.

8. The combustor of claim 1 , wherein the brief severe quench zone comprises a plurality of quench air injectors to provide the outer quench air flow.

9. The combustor of claim 1 , wherein the expansion zone comprises one or more lean recirculation zones therein.

10. The combustor of claim 1 , further comprising a transition piece downstream of the expansion zone.

11. The combustor of claim 1 , further comprising an impingement cooled liner.

12. A method of combusting a flow of air and a flow of fuel in a combustor, comprising:

combusting in part the flow of fuel and the flow of air in a trapped vortex cavity for a low temperature rich combustion, wherein the trapped vortex cavity surrounds a central swirler such that an aft end wall at least partially overlaps with the central swirler;

quenching the low temperature rich combustion in a brief severe quench zone into rich combustion products, wherein the brief severe quench zone comprises a liner with a constricted shape downstream of the trapped vortex cavity, and a plurality of slots comprising a herringbone-like pattern, such that alternating rows of the plurality of slots are positioned in different directions so as to form a V shape; and

combusting the rich combustion products in an expansion zone downstream of the brief severe quench zone for a low temperature lean combustion.

13. A combustor for combusting a number of flows of air and a number of flows of fuel, comprising:

a central swirler for producing a high swirl quench air flow;

a plurality of trapped vortex cavities surrounding the central swirler for producing a flow of combustion gases, such that an aft end wall of each of the plurality of trapped vortex cavities at least partially overlaps with the central swirler; and

a brief severe quench zone comprising a liner with a constricted shape downstream of the plurality of trapped vortex cavities, wherein the high swirl quench air flow and the flow of combustion gases are delivered to the constricted shape of the brief severe quench zone;

the brief severe quench zone comprising a plurality of quench air injectors and a plurality of slots therein for producing an outer quench air flow so as to quench the flow of combustion gases between the outer quench air flow and the high swirl quench air flow, wherein the plurality of slots comprises a herringbone-like pattern, such that alternating rows of the plurality of slots are positioned in different directions so as to form a V shape.

14. The combustor of claim 13 , further comprising an expansion zone with an expanded shape downstream of the brief severe quench zone.

15. The combustor of claim 13 , wherein the plurality of trapped vortex cavities comprises a gas fuel injector and a liquid fuel injector.