Catalytic fuel tank inerting system
Fuel tank inerting systems are provided. The systems include a fuel tank, an air source arranged to supply air into a reactive flow path, a catalytic reactor having a plurality of sub-reactors along the flow path, and a heat exchanger. The sub-reactors are arranged relative to the heat exchanger such that the flow path passes through at least a portion of the heat exchanger between two sub-reactors along the flow path. At least one fuel injector is arranged relative to at least one sub-reactor. The fuel injector is configured to inject fuel into the flow path at at least one of upstream of and in the respective at least one sub-reactor to generate a fuel-air mixture. A fuel tank ullage supply line fluidly connects the flow path to the fuel tank to supply an inert gas to a ullage of the fuel tank.
1. A fuel tank inerting system, comprising
a fuel tank;
an air source arranged to supply air into a reactive flow path;
a catalytic reactor comprising a plurality of sub-reactors arranged in series along the reactive flow path, the plurality of sub-reactors comprising a first sub-reactor and a second sub-reactor;
a heat exchanger arranged along the reactive flow path, wherein at least a portion of the heat exchanger is arranged between the first sub-reactor and the second sub-reactor along the reactive flow path;
at least one fuel injector arranged relative to at least one sub-reactor of the plurality of sub-reactors, the at least one fuel injector configured to inject fuel into the reactive flow path at at least one of upstream of and in the respective at least one sub-reactor to generate a fuel-air mixture; and
a fuel tank ullage supply line fluidly connecting the reactive flow path to the fuel tank to supply an inert gas to a ullage of the fuel tank.
2. The fuel tank inerting system of claim 1 , wherein the at least one fuel injector comprises a plurality of fuel injectors arranged along the reactive flow path.
3. The fuel tank inerting system of claim 1 , wherein the at least one fuel injector is a passive flow control to meter injection of the fuel into the reactive flow path.
4. The fuel tank inerting system of claim 3 , wherein the at least one fuel injector is a valve and wherein a fluid pressure of the fuel determines a fuel injection rate.
5. The fuel tank inerting system of claim 1 , wherein the at least one fuel injector is an active flow control to meter injection of the fuel into the reactive flow path, wherein a controller controls operation of the at least one fuel injector.
6. The fuel tank inerting system of claim 5 , wherein the at least one fuel injector is at least one of electrically controlled, electronically controlled, and mechanically controlled.
7. The fuel tank inerting system of claim 1 , further comprising a supplemental fuel line fluidly connecting the fuel tank to the at least one fuel injector.
8. The fuel tank inerting system of claim 1 , wherein a number of fuel injectors is equal to the number of sub-reactors of the plurality of sub-reactors.
9. The fuel tank inerting system of claim 1 , wherein as the heat exchanger comprises a plurality of cells, wherein each cell of the heat exchanger is positioned between two sub-reactors with the reactive flow path passing through the cells to cool the fuel-air mixture.
10. The fuel tank inerting system of claim 1 , wherein the plurality of sub-reactors comprises at least four sub-reactors.
11. The fuel tank inerting system of claim 10 , wherein the plurality of sub-reactors comprises at least six sub-reactors.
12. The fuel tank inerting system of claim 1 , wherein the fuel tank is a fuel tank of an aircraft, and a cooling air within the heat exchanger is sourced from a ram inlet of the aircraft.
13. An aircraft comprising:
a fuel tank;
an air source arranged to supply air into a reactive flow path;
a catalytic reactor comprising a plurality of sub-reactors arranged in series along the reactive flow path, the plurality of sub-reactors comprising a first sub-reactor and a second sub-reactor;
a heat exchanger arranged along the reactive flow path, wherein at least a portion of the heat exchanger is arranged between the first sub-reactor and the second sub-reactor along the reactive flow path;
at least one fuel injector arranged relative to at least one sub-reactor of the plurality of sub-reactors, the at least one fuel injector configured to inject fuel into the reactive flow path at at least one of upstream of and in the respective at least one sub-reactor to generate a fuel-air mixture; and
a fuel tank ullage supply line fluidly connecting the reactive flow path to the fuel tank to supply an inert gas to a ullage of the fuel tank.
14. The aircraft of claim 13 , wherein the at least one fuel injector comprises a plurality of fuel injectors arranged along the reactive flow path.
15. The aircraft of claim 13 , wherein the at least one fuel injector is a passive flow control to meter injection of the fuel into the reactive flow path.
16. The aircraft of claim 13 , wherein the at least one fuel injector is an active flow control to meter injection of the fuel into the reactive flow path, wherein a controller controls operation of the at least one fuel injector.
17. The aircraft of claim 13 , further comprising a supplemental fuel line fluidly connecting the fuel tank to the at least one fuel injector.
18. The aircraft of claim 13 , wherein as the heat exchanger comprises a plurality of cells, wherein each cell of the heat exchanger is positioned between two sub-reactors with the reactive flow path passing through the cells to cool the fuel-air mixture.
19. The aircraft of claim 13 , wherein the plurality of sub-reactors comprises at least four sub-reactors.
20. The aircraft of claim 19 , wherein the plurality of sub-reactors comprises at least six sub-reactors.