Nuclear thermal propulsion system with reactor direct drive of cryocooler turbine

Patent metadata

Field	Value
Publication number	US-11975870-B2
Application number	US-202217808256-A
Country	US
Kind code	B2
Filing date	Jun 22, 2022
Priority date	Jun 22, 2022
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

Systems and methods for nuclear reactor direct drive of a cryocooler turbine. A nuclear thermal propulsion (NTP) system may have a nuclear reactor that heats a thermal working fluid for directly driving the turbine to power a cryogenic fluid management (CFM) system for keeping propellant at cryogenic temperatures. The features may be used on NTP rockets. The propellant may be liquid hydrogen.

First claim

What is claimed is:

1. A method for powering a cryogenic fluid management (CFM) system in a nuclear thermal propulsion (NTP) rocket, the method comprising:
heating a first thermal working fluid in a first fluid circuit via thermal communication of the first thermal working fluid with a nuclear reactor core of the NTP rocket;
driving a cryocooler turbine of the CFM system using the heated first thermal working fluid;
driving a first compressor and a second compressor via a shaft rotated by the cryocooler turbine;
circulating the first thermal working fluid through the first compressor and a second thermal working fluid in a second fluid circuit through the second compressor; and
maintaining a cryogenic temperature of propellant via the second thermal working fluid using the driven second compressor and cryocooler turbine.

2. The method of claim 1 , further comprising circulating the first thermal working fluid back to thermal communication with the nuclear reactor core of the NTP rocket.

3. The method of claim 1 , wherein maintaining the cryogenic temperature of the propellant comprises circulating the second thermal working fluid below 20 K in thermal communication with the propellant.

4. The method of claim 1 , further comprising powering the CFM system in the NTP rocket for multiple years.

5. The method of claim 1 , wherein the first thermal working fluid is He—Xe.

6. The method of claim 1 , wherein the second thermal working fluid is liquid He.

7. The method of claim 1 , wherein the propellant is liquid hydrogen.

8. A system for powering a cryogenic fluid management (CFM) system in a nuclear thermal propulsion (NTP) rocket, the system comprising:
a nuclear reactor core configured to heat a first thermal working fluid via a first fluid circuit;
a cryocooler turbine configured to be directly driven by the heated first thermal working fluid; and
the CFM system comprising two or more compressors configured to be powered by a shaft rotated by the driven cryocooler turbine to maintain via a second fluid circuit a liquid state of propellant in a cryogenic tank,
wherein the two or more compressors comprises a first compressor configured to be driven by the cryocooler turbine via the shaft and through which the first thermal working fluid is configured to circulate via the first fluid circuit, and
wherein the two or more compressors further includes a second compressor configured to be driven by the cryocooler turbine via the shaft and through which a second thermal working fluid is configured to circulate via the second fluid circuit and that cools the propellant stored in the cryogenic tank.

9. The system of claim 8 , wherein the first thermal working fluid is He—Xe and the second thermal working fluid is liquid He.

10. The system of claim 8 , wherein the propellant is liquid hydrogen.

11. The system of claim 8 , further comprising a shield configured to reduce a total radiation dose on components of the CFM system and to limit gamma and neutronic heating of the propellant stored in the tank.

12. The system of claim 8 , wherein the CFM system comprises a reverse turbo-Brayton cryocooler.

13. A method for operating a cryocooler turbine in a nuclear thermal propulsion (NTP) rocket, the method comprising:
heating a first thermal working fluid via thermal communication of the first thermal working fluid with a nuclear reactor core of the NTP rocket;
circulating the first thermal working fluid along a first fluid circuit to the cryocooler turbine of a cryogenic fluid management (CFM) system;
driving the cryocooler turbine with the heated first thermal working fluid;
driving a first compressor of the CFM system via a shaft rotated by the cryocooler turbine;
circulating the first thermal working fluid from the cryocooler turbine along the first fluid circuit and through the first compressor;
circulating the first thermal working fluid from the first compressor back to thermal communication with the nuclear reactor core;
cooling a second thermal working fluid via thermal communication of the second thermal working fluid with a heat exchanger;
circulating the second thermal working fluid along a second fluid circuit to a cryogenic tank storing propellant;
cooling the propellant via thermal communication of the second thermal working fluid with the cryogenic tank;
driving a second compressor of the CFM system via the shaft rotated by the cryocooler turbine;
circulating the second thermal working fluid from the cryogenic tank along the second fluid circuit and through the second compressor; and
circulating the second thermal working fluid from the second compressor back to thermal communication with the heat exchanger.

14. The method of claim 13 , further comprising operating the cryocooler turbine in the NTP rocket for multiple years.

15. The method of claim 13 , wherein the first thermal working fluid is He—Xe.

16. The method of claim 13 , wherein the second thermal working fluid is liquid He.

17. The method of claim 13 , wherein the propellant is liquid hydrogen.

18. The method of claim 13 , wherein the second thermal working fluid is cooled to below 20 K.

19. The method of claim 13 , further comprising circulating the propellant to cool a nozzle of the NTP rocket.

20. The method of claim 19 , further comprising circulating the propellant through the nuclear reactor core and expelling the propellant out of the nozzle.

Assignees

• Blue Origin Llc

Inventors

• Tolley Zachary Reid

Classifications

• B64G1/408 Primary

  Nuclear spacecraft propulsion · CPC title

• F02K9/42

  using liquid or gaseous propellants (F02K9/72 takes precedence) · CPC title

• F02K9/425

  Propellants · CPC title

• F02K9/44 Primary

  Feeding propellants · CPC title

• F02K9/50

  using pressurised fluid to pressurise the propellants · CPC title