Supercritical fluid systems
Supercritical fluid systems and aircraft power systems are described. The systems include a compressor, a turbine operably coupled to the compressor, a generator operably coupled to the turbine and configured to generate power, a primary working fluid flow path having a primary working fluid configured to pass through the compressor, a separator, the turbine, and back to the compressor, and a secondary working fluid flow path passing through the generator, the compressor, the separator, and back to the generator. The primary working fluid is supercritical carbon dioxide (sCO 2 ) and the secondary working fluid is a fluid having at least one of a density less than the primary working fluid and a molecular size smaller than the primary working fluid.
1. A supercritical fluid system comprising:
a compressor;
a turbine operably coupled to the compressor;
a generator operably coupled to the turbine and configured to generate power;
a primary working fluid flow path having a primary working fluid configured to pass through the compressor, a separator, the turbine, and back to the compressor; and
a secondary working fluid flow path passing through the generator, the compressor, the separator, and back to the generator,
wherein the primary working fluid is supercritical carbon dioxide (sCO 2 ) and the secondary working fluid is a fluid having at least one of a density less than the primary working fluid and a molecular size smaller than the primary working fluid.
2. The supercritical fluid system of claim 1 , wherein the secondary working fluid is hydrogen.
3. The supercritical fluid system of claim 1 , wherein the secondary working fluid is helium.
4. The supercritical fluid system of claim 1 , wherein the compressor and the turbine are part of a waste heat recovery system of a gas turbine engine.
5. The supercritical fluid system of claim 1 , wherein the separator is configured to separate the primary working fluid from the secondary working fluid from a mixture of the two.
6. The supercritical fluid system of claim 5 , wherein the mixture is generated within the compressor.
7. The supercritical fluid system of claim 5 , wherein the separator is a cyclone separator or a gravity separator.
8. The supercritical fluid system of claim 5 , wherein the separator is a membrane separator.
9. The supercritical fluid system of claim 1 , further comprising a recuperating heat exchanger arranged along the primary working fluid flow path.
10. The supercritical fluid system of claim 1 , wherein the generator includes a rotor, wherein the secondary working fluid flow path passes along the rotor to provide cooling thereto.
11. The supercritical fluid system of claim 10 , wherein the secondary working fluid is configured to prevent entrainment of the primary working fluid around the rotor.
12. The supercritical fluid system of claim 1 , wherein the compressor is a shrouded blade compressor and the secondary working fluid is directed to provide cooling to shrouded blades of the shrouded blade compressor.
13. The supercritical fluid system of claim 1 , wherein the turbine is a shrouded blade turbine and the secondary working fluid is directed to provide cooling to shrouded blades of the shrouded blade turbine.
14. The supercritical fluid system of claim 1 , further comprising a cooling heat exchanger arranged along the secondary working fluid flow path between the separator and the generator.
15. The supercritical fluid system of claim 1 , wherein the compressor, the generator, and the turbine are part of an industrial generator.
16. An aircraft power system comprising:
at least one engine; and
a supercritical fluid system comprising:
a compressor;
a turbine operably coupled to the compressor;
a generator operably coupled to the turbine and configured to generate power;
a primary working fluid flow path having a primary working fluid configured to pass through the compressor, a separator, the turbine, and back to the compressor; and
a secondary working fluid flow path passing through the generator, the compressor, the separator, and back to the generator,
wherein the primary working fluid is supercritical carbon dioxide (sCO 2 ) and the secondary working fluid is a fluid having at least one of a density less than the primary working fluid and a molecular size smaller than the primary working fluid.
17. The aircraft power system of claim 16 , wherein the supercritical fluid system is configured as a waste heat recovery system for the at least one engine.
18. The aircraft power system of claim 16 , wherein the secondary working fluid is hydrogen.
19. The aircraft power system of claim 16 , wherein the secondary working fluid is helium.
20. The aircraft power system of claim 16 , wherein the supercritical fluid system is configured to generate power for the aircraft.