Hydrogen liquid oxygen combined cycle engine

Patent metadata

Field	Value
Publication number	US-12259134-B2
Application number	US-202318342016-A
Country	US
Kind code	B2
Filing date	Jun 27, 2023
Priority date	Jun 27, 2023
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

A propulsion system for an air vehicle includes a fan system that includes a fan that is coupled to a fan drive electric motor for generating a fan discharge airflow, an augmentor where fuel is mixed with a portion of the fan discharge airflow to generate a propulsive flow in a first operating configuration, a bypass duct for directing the fan discharge airflow into the augmentor, a duct blocker for selectively closing the bypass duct to the fan discharge airflow, a liquid oxygen system that is configured to inject liquid oxygen into the augmentor to mix with the fuel when the fan discharge airflow is closed by the duct blocker, the mixture of fuel flow and liquid oxygen generates the propulsive flow in a second operating configuration, and an electric power generation system is coupled to drive the fan drive electric motor.

First claim

What is claimed is:

1. A propulsion system for an air vehicle comprising: a fan system including a fan coupled to a fan drive electric motor for generating a fan discharge airflow; an augmentor where fuel is mixed with a portion of the fan discharge airflow to generate a propulsive flow in a first operating configuration; a bypass duct for directing the fan discharge airflow into the augmentor; a duct blocker for selectively closing the bypass duct to the fan discharge airflow; a fuel system configured to generate a fuel flow; a liquid oxygen system configured to inject liquid oxygen into the augmentor to mix with the fuel flow when the fan discharge airflow is closed by the duct blocker, wherein the mixture of the fuel flow and liquid oxygen generates the propulsive flow in a second operating configuration; and an electric power generation system comprising a fuel turbopump driven by an exhaust gas flow generated by a first pre-burner, an oxidizer turbopump driven by an exhaust gas flow generated in a second pre-burner, a combustor where exhaust gas flows from both the first pre-burner and the second pre-burner are mixed with fuel and liquid oxygen to generate an exhaust gas flow that is expanded through-a free turbine, wherein the free turbine is coupled to drive a generator that provides electric power to the fan drive electric motor, wherein the fan system is disposed along an engine axis and the power generation system is disposed along a secondary axis that is different than the engine axis.

2. The propulsion system as recited in claim 1 , further including a translating inlet movable between an open position allowing inlet airflow to the fan system and a closed position shutting inlet airflow to the fan system.

3. The propulsion system as recited in claim 1 , wherein the exhaust gas flow exhausted from the free turbine and is exhausted through a nozzle.

4. The propulsion system as recited in claim 1 , including a gearbox driven by the free turbine and including an output coupled to drive the generator.

5. The propulsion system as recited in claim 1 , wherein the propulsive flow from the augmentor is expelled through a converging diverging nozzle.

6. The propulsion system as recited in claim 2 , wherein in the first operating configuration, the fan generates a fan discharge flow directly to the augmenter and in the second operating configuration, the translating inlet is closed and the propulsive flow is generated by combustion of a mixture of fuel and liquid oxygen in the augmentor.

7. The propulsion system as recited in claim 1 , wherein the fan of the fan system comprises a multi-stage fan.

8. The propulsion system as recited in claim 1 , further comprising a manifold where gas flows exhausted from each of the fuel turbopump and the oxidizer turbopump are communicated to the combustor.

9. The propulsion system as recited in claim 1 , wherein the free turbine is cooled by a gaseous oxygen flow exiting an oxygen cooling flow heat exchanger.

10. The propulsion system as recited in claim 1 , further comprising a recuperator where heat from the exhaust gas flow pre-heats the fuel flow before injection into at least one of the first and second pre-burners and the combustor.

11. An aircraft propulsion system comprising: a fan system including a fan coupled to a fan drive electric motor configured to generate a fan discharge flow, wherein the fan is selectively driven by only the fan drive electric motor; a translating inlet movable between an open position allowing inlet airflow to the fan system and a closed position closing off inlet airflow to the fan system; a fuel system providing a flow of fuel; an augmentor configured to generate a propulsive gas flow from a mixture of fuel and the fan discharge airflow in a first engine operating configuration; a duct blocker movable between an open and a closed position for controlling the fan discharge flow to the augmentor; and a liquid oxygen system configured to provide oxygen to the augmentor to mix with the fuel and generate the propulsive gas flow in a second engine operating configuration, wherein in the second engine operating configuration, the duct blocker is in a closed position such that no fan discharge flow is communicated to the augmentor; and an electric power generation system comprising a fuel turbopump for pressurizing a fuel flow communicated to a combustor, an oxidizer turbopump for pressurizing a liquid oxygen flow to the combustor, a first pre-burner where a gas flow is generated for driving the fuel turbopump, a second pre-burner where a gas flow is generated for driving the oxidizer turbopump, a combustor a combustor where gas flows from each of the first pre-burner and the second pre-burner are received, mixed with fuel and liquid oxygen to generate an exhaust gas flow for driving; a free turbine coupled to a generator, wherein the free turbine is driven by an exhaust gas flow generated in the combustor and is only coupled to drive the generator, wherein the fan system is disposed along an engine axis and the electric power generation system is disposed along a secondary axis that is different than the engine axis.

12. The aircraft propulsion system as recited in claim 11 , wherein the fan of the fan system comprises a multi-stage fan.

13. The propulsion system as recited in claim 11 , further comprising a manifold where gas flows exhausted from each of the fuel turbopump and the oxidizer turbopump are communicated to the combustor.

14. The propulsion system as recited in claim 11 , wherein the free turbine is cooled by a gaseous oxygen flow exiting an oxygen cooling flow heat exchanger.

15. The propulsion system as recited in claim 11 , further comprising a recuperator where heat from the exhaust gas flow pre-heats the fuel flow before injection into at least one of the first and second pre-burners and the combustor.

16. A method of operating an aircraft propulsion system comprising: generating electric power with a free turbine driven generator, wherein the free turbine is driven by a power generating system comprising a fuel turbopump driven by an exhaust gas flow generated by a first pre-burner, an oxidizer turbopump driven by an exhaust gas flow generated in a second pre-burner, a combustor where exhaust gas flows from both the first pre-burner and the second pre-burner are mixed with additional fuel and liquid oxygen to generate an exhaust gas flow that is expanded through the free turbine; driving a fan with an electric motor to generate a fan discharge flow, wherein the electric motor is driven by the generated electric power from the generator; mixing the fan discharge airflow with fuel in an augmentor to generate a propulsive gas flow exhausted through a nozzle in a first engine operating configuration; and closing off the fan discharge airflow to the augmentor and communicating an oxygen flow to the augmentor for mixing with the fuel to generate the propulsive gas flow that is exhausted through the nozzle in a second engine operating configuration, wherein the fan is disposed along an engine axis and the power generation system is disposed along a secondary axis that is different than the engine axis.

17. The method as recited in claim 16 , wherein generating electric power comprises generating an exhaust gas flow from a flow of oxygen and fuel ignited in a combustor for driving the free turbine in an electricity generation system separate from the fan.

18. The method as recited in claim 16 , further comprising controlling inlet flow to the fan with a translating inlet, wherein the translating inlet is op

Assignees

• Raytheon Tech Corp
• Rtx Corp

Inventors

• Ledwith Jr Walter A
• Lei Ma David

Classifications

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F02C9/18

  by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} · CPC title

• F02C7/22

  Fuel supply systems · CPC title

• F01D15/10

  Adaptations for driving, or combinations with, electric generators · CPC title

• F05D2220/76

  an electrical generator · CPC title