Concentric catalytic combustor

1. A catalytic combustor comprising:

a plurality of concentric tubular pressure boundary elements forming a first annular space conducting a first fluid flow and a second annular space separate from the first annular space conducting a second fluid flow; wherein the first fluid flow comprises a combustible fluid and the second fluid flow comprises a cooling fluid containing no combustible fuel; and

a catalytic material disposed on a surface of at least one of the pressure boundary elements and exposed to at least one of the fluid flows.

2. The catalytic combustor of claim 1 , wherein the surface comprises an inner diameter surface of the pressure boundary element.

3. The catalytic combustor of claim 1 , wherein the surface comprises an outer diameter surface of the pressure boundary element.

4. The catalytic combustor of claim 1 , wherein the surface comprises an outer diameter surface of a first pressure boundary element and an inner diameter surface of a second pressure boundary element concentrically disposed around the first pressure boundary element.

5. A catalytic combustor comprising:

a plurality of concentric tubular pressure boundary elements forming a first annular space conducting a first fluid flow and a second annular space separate from the first annular space conducting a second fluid flow, wherein the first fluid flow comprises a combustible fluid and the second fluid flow comprises a cooling fluid containing no combustible fuel; and

a catalytic material disposed on a surface of at least one of the pressure boundary elements and exposed to at least one of the fluid flows;

the catalytic combustor, further comprising a support structure radially disposed between a first pressure boundary element and a second pressure boundary element disposed concentrically around the first pressure boundary element and within the second annular space, the support structure radially retaining the first and second first pressure boundary elements in a spaced configuration.

6. A catalytic combustor comprising:

a plurality of concentric tubular pressure boundary elements forming a first annular space conducting a first fluid flow and a second annular space separate from the first annular space conducting a second fluid flow; and

a catalytic material disposed on a surface of at least one of the pressure boundary elements and exposed to at least one of the fluid flows;

wherein the pressure boundary elements are configured to form a plurality of first annular spaces defined by a surface comprising a catalytic material concentrically alternating with a plurality of second annular spaces defined by surfaces comprising no catalytic material.

7. The catalytic combustor of claim 6 , further comprising a combustible fluid flow controller for independently controlling a combustible fluid flow to at least one of the plurality of first annular spaces independently of other first annular spaces.

8. A catalytic combustor comprising:

a plurality of concentric tubular pressure boundary elements forming a first annular space conducting a first fluid flow and a second annular space separate from the first annular space conducting a second fluid flow; and

a catalytic material disposed on a surface of at least one of the pressure boundary elements and exposed to at least one of the fluid flows;

the catalytic combustor further comprising a pilot burner disposed within a radially innermost pressure boundary element.

9. A catalytic combustor comprising:

a plurality of concentric tubular pressure boundary elements forming a first annular space conducting a first fluid flow and a second annular space separate from the first annular space conducting a second fluid flow; and

a catalytic material disposed on a surface of at least one of the pressure boundary elements anti exposed to at least one of the fluid flows;

the catalytic combustor further comprising a manifold assembly attached to an upstream end of the combustor, the manifold assembly comprising a radial passageway receiving the first fluid flow and conducting the first fluid flow into annular spaces formed in the manifold assembly in fluid communication with respective annular spaces formed by the plurality of concentric tubular pressure boundary elements.

10. The catalytic combustor of claim 9 , the manifold assembly comprising a central opening receiving the first fluid flow and conducting the first fluid flow into the radial passageway.

11. The catalytic combustor of claim 10 , the manifold assembly comprising an axial passageway remote from the radial passageways receiving the second fluid flow and conducting the second fluid flow into the second annular space.

12. A catalytic combustor comprising:

a plurality of catalytic combustion modules, each module comprising a plurality of concentric tubular pressure boundary elements forming a first annular space conducting a first fluid flow and a second annular space separate from the first annular space and conducting a second fluid flow and a catalytic surface disposed in at least one of the annular spaces and exposed to the flow conducted therethrough;

one of the plurality of the modules disposed along a central axis of the combustor;

remaining ones of the plurality of modules circumferentially disposed about the central axis radially outward of the one of the plurality of modules; and

each module comprising a pilot burner disposed in a central region of the respective module.

13. A catalytic combustor comprising:

a plurality of catalytic combustion modules, each module comprising a plurality of concentric tubular pressure boundary elements forming a first annular space conducting a first fluid flow and a second annular space separate from the first annular space conducting a second fluid flow and a catalytic surface disposed in at least one of the annular spaces and exposed to flow conducted therethrough; and

each module clrcumferentially disposed about a central axis radially outward of a central region of the combustor;

the catalytic combustor further comprising a pilot burner disposed in the central region.