Extracting water vapor from a powerplant exhaust

1. A powerplant, comprising:

a flowpath;

a combustor configured to generate combustion products and direct the combustion products through the flowpath, the combustion products including water vapor;

a water extraction system arranged with the flowpath downstream of the combustor, the water extraction system including a condensation seeder and a collector;

the condensation seeder configured to direct a plurality of small water droplets into the flowpath to promote condensation of the water vapor to grow the plurality of small water droplets into a plurality of large water droplets; and

the collector configured to collect the plurality of large water droplets; and

a control system configured to

monitor conditions entering the water extraction system;

monitor a quantity of water extracted from the combustion products by the water extraction system; and

adjust water pressure and/or flow rater to the condensation seeder to control a condensation rate of the water vapor.

2. The powerplant of claim 1 , wherein

the flowpath extends axially along an axial centerline; and

the condensation seeder comprises a nozzle configured to direct at least some of the plurality of small water droplets into the flowpath along a trajectory tangent to a reference line extending circumferentially about the axial centerline.

3. The powerplant of claim 1 , wherein

the flowpath extends axially along an axial centerline; and

the condensation seeder comprises a nozzle configured to direct at least some of the plurality of small water droplets into the flowpath along a trajectory angularly offset from the axial centerline.

4. The powerplant of claim 3 , wherein the trajectory is perpendicular to the axial centerline.

5. The powerplant of claim 3 , wherein the trajectory is angularly offset from the axial centerline by an acute angle.

6. The powerplant of claim 1 , wherein

the flowpath extends axially along an axial centerline;

the condensation seeder includes a plurality of nozzles configured to direct the plurality of small water droplets into the flowpath; and

the plurality of nozzles include a first nozzle and a second nozzle axially spaced from the first nozzle along the axial centerline.

7. The powerplant of claim 1 , wherein the collector comprises one or more fins and/or one or more coils.

8. The powerplant of claim 1 , wherein the collector comprises a centrifugal water-gas separator.

9. The powerplant of claim 1 , further comprising a reservoir configured to receive water from the collector, the water comprising the plurality of large water droplets.

10. The powerplant of claim 1 , further comprising a heater configured to heat water provided to the condensation seeder for forming the plurality of small water droplets.

11. The powerplant of claim 1 , further comprising a cooler configured to cool water provided to the condensation seeder for forming the plurality of small water droplets.

12. The powerplant of claim 1 , further comprising:

a turbine rotor arranged along the flowpath downstream of the combustor;

the water extraction system arranged with the flowpath between the combustor and the turbine rotor.

13. The powerplant of claim 1 , further comprising a turbine rotor arranged along the flowpath between the combustor and the water extraction system.

14. The powerplant of claim 1 , further comprising:

a first turbine rotor arranged along the flowpath downstream of the combustor; and

a second turbine rotor arranged along the flowpath downstream of the first turbine rotor;

the water extraction system arranged with the flowpath between the first turbine rotor and the second turbine rotor.

15. The powerplant of claim 1 , further comprising a fuel system configured to direct hydrogen fuel into the combustor for combustion to generate the combustion products.

16. The powerplant of claim 1 , further comprising a heat exchanger arranged with the flowpath upstream of the condensation seeder, the heat exchanger configured to cool the combustion products directed through the flowpath.

17. A powerplant, comprising:

a flowpath;

a combustor configured to generate combustion products using non-hydrocarbon fuel and direct the combustion products through the flowpath;

a water extraction system configured to extract water vapor from the combustion products, the water extraction system comprising a plurality of nozzles configured to direct a plurality of water droplets into the flowpath; and

a control system configured to

monitor conditions entering the water extraction system;

monitor a quantity of water extracted from the combustion products by the water extraction system; and

adjust water pressure and/or flow rater to a condensation seeder to control a condensation rate of the water vapor.

18. The powerplant of claim 17 , wherein

the water extraction system is configured to direct the plurality of water droplets into the flowpath using the plurality of nozzles to promote condensation of the water vapor to grow the plurality of water droplets into a plurality of larger water droplets; and

the water extraction system is configured collect the plurality of larger water droplets for removal from the flowpath.

19. A method for operating a powerplant, comprising:

combusting fuel within a combustor to provide combustion products; and

extracting water vapor from the combustion products downstream of the combustor using a water extraction system, the extracting of the water vapor comprising

introducing a plurality of small water droplets into a flowpath to promote condensation of the water vapor within the flowpath and grow the plurality of small water droplets with the condensing water vapor into a plurality of large water droplets;

collecting the plurality of large water droplets for removal from the flowpath;

monitoring conditions entering the water extraction system;

monitoring a quantity of water extracted from the combustion products by the water extraction system; and

adjusting water pressure and/or flow rate to condensation seeder to control a condensation rate of the water vapor.