Dual reheat rankine cycle system and method thereof

1. A rankine cycle system, comprising:

a heater configured to circulate a working fluid in heat exchange relationship with a hot fluid to vaporize the working fluid;

a hot system coupled to the heater; wherein the hot system comprises a first heat exchanger configured to circulate a first vaporized stream of the working fluid from the heater in heat exchange relationship with a first condensed stream of the working fluid to heat the first condensed stream of the working fluid;

a cold system coupled to the heater and the hot system; wherein the cold system comprises a second heat exchanger configured to circulate a second vaporized stream of the working fluid from the hot system in heat exchange relationship with a second condensed stream of the working fluid to heat the second condensed stream of the working fluid before being fed to the heater;

wherein the hot system comprises a first expander configured to expand the first vaporized stream of the working fluid from the heater, and

wherein the hot system comprises a first condensing unit configured to condense the expanded first vaporized stream of the working fluid fed from the heater via the first heat exchanger, and

wherein the hot system comprises a first pump configured to feed the first condensed stream of the working fluid via the first heat exchanger to generate the second vaporized stream of the working fluid, and

wherein the cold system comprises a second expander configured to expand the second vaporized stream of the working fluid from the first heat exchanger, and

wherein the cold system comprises a second condensing unit configured to condense the expanded second vaporized stream of the working fluid fed from the second expander via the second heat exchanger.

2. The system of claim 1 , wherein the cold system comprises a second pump configured to feed the second condensed stream of the working fluid via the second heat exchanger to the heater.

3. The system of claim 1 , wherein the first condensing unit comprises an air cooler configured to cool the expanded first vaporized stream of the working fluid fed from the heater via the first heat exchanger.

4. The system of claim 3 , wherein the first condensing unit comprises a first separator configured to separate a first uncondensed vapor stream from the first condensed stream of the working fluid exiting from the air cooler.

5. The system of claim 4 , wherein the first condensing unit comprises a third expander configured to expand one portion of the first uncondensed vapor stream.

6. The system of claim 5 , wherein the first condensing unit comprises a second separator configured to separate a second uncondensed vapor stream from the expanded one portion of the first uncondensed vapor stream exiting the third expander.

7. The system of claim 6 , wherein the first condensing unit comprises a third heat exchanger configured to circulate the second uncondensed vapor stream in heat exchange relationship with a remaining portion of the first uncondensed vapor stream to condense the remaining portion of the first uncondensed vapor stream.

8. The system of claim 7 , wherein the first condensing unit comprises a compressor coupled to the third expander and configured to compress the second uncondensed vapor stream from the third heat exchanger and feed to an upstream side of the air cooler.

9. The system of claim 7 , wherein the first condensed stream of the working fluid exiting via the first separator, a third condensed stream of the working fluid exiting via the second separator, a fourth condensed stream of the working fluid exiting via the third heat exchanger are fed to the first pump.

10. The system of claim 1 , wherein the second condensing unit comprises an air cooler configured to cool the expanded second vaporized stream of the working fluid fed from the second expander via the second heat exchanger.

11. The system of claim 10 , wherein the second condensing unit comprises a third separator configured to separate a second uncondensed vapor stream from the second condensed stream of the working fluid exiting from the air cooler.

12. The system of claim 11 , wherein the second condensing unit comprises a fourth expander configured to expand one portion of the second uncondensed vapor stream.

13. The system of claim 12 , wherein the second condensing unit comprises a fourth separator configured to separate a third uncondensed vapor stream from the expanded one portion of the second uncondensed vapor stream exiting the fourth expander.

14. The system of claim 13 , wherein the second condensing unit comprises a fourth heat exchanger configured to circulate the third uncondensed vapor stream in heat exchange relationship with a remaining portion of the second uncondensed vapor stream to condense the remaining portion of the second uncondensed vapor stream.

15. The system of claim 14 , wherein the second condensing unit comprises a compressor coupled to the fourth expander and configured to compress the third uncondensed vapor stream from the fourth heat exchanger and feed to an upstream side of the air cooler.

16. The system of claim 14 , wherein the second condensed stream of the working fluid exiting via the third separator, a fifth condensed stream exiting via the fourth separator, a sixth condensed stream exiting via the fourth heat exchanger are fed to the second pump.

17. The system of claim 1 , wherein the working fluid comprises carbon dioxide.

18. The system of claim 1 , wherein the hot fluid comprises an exhaust gas.

19. A method, comprising:

circulating a working fluid in heat exchange relationship with a hot fluid via a heater to vaporize the working fluid;

circulating a first vaporized stream of the working fluid from the heater in heat exchange relationship with a first condensed stream of the working fluid via a first heat exchanger of a hot system to heat the first condensed stream of the working fluid; and

circulating a second vaporized stream of the working fluid from the hot system in heat exchange relationship with a second condensed stream of the working fluid via a second heat exchanger of a cold system to heat the second condensed stream of the working fluid before being fed to the heater;

wherein the first vaporized stream of the working fluid is expanded via a first expander of the hot system, and

wherein the expanded first vaporized stream of the working fluid is condensed in a first condensing unit of the hot system, and

wherein the second vaporized stream of the working fluid from the first heat exchanger is expanded via a second expander of the cold system, and

wherein the expanded second vaporized stream is condensed via a second condensing unit of the cold system.

20. The method of claim 19 , further comprising cooling the expanded first vaporized stream of the working fluid via an air cooler.

21. The method of claim 19 , further comprising separating a first uncondensed vapor stream from the first condensed stream of the working fluid via a first separator.

22. The method of claim 21 , further comprising expanding one portion of the first uncondensed vapor stream via a third expander.

23. The method of claim 22 , further comprising separating a second uncondensed vapor stream from the expanded one portion of the first uncondensed vapor stream via a second separator.

24. The method of claim 23 , further comprising circulating the second uncondensed vapor stream in heat exchange relationship with a remaining portion of the first uncondensed vapor stream to condense the remaining portion of the first uncondensed vapor stream via a third heat exchanger.

25. The method of claim 24 , further comprising compressing the second uncondensed vapor stream from the third heat exchanger and feeding to an upstream side of the air cooler via a compressor.

26. The method of claim 24 , further comprising feeding the first condensed stream of the working fluid exiting via the first separator, a third condensed stream of the working fluid exiting via the second separator, a fourth condensed stream of the working fluid exiting via the third heat exchanger to the first pump.

27. The method of claim 19 , further comprising cooling the expanded second vaporized stream of the working fluid via an air cooler of the second condensing unit.

28. The method of claim 27 , further comprising separating a second uncondensed vapor stream from the second condensed stream of the working fluid via a third separator.

29. The method of claim 28 , further comprising expanding one portion of the second uncondensed vapor stream via a fourth expander.

30. The method of claim 29 , further comprising separating a third uncondensed vapor stream from the expanded one portion of the second uncondensed vapor stream via the fourth separator.

31. The method of claim 30 , further comprising circulating the third uncondensed vapor stream in heat exchange relationship with a remaining portion of the second uncondensed vapor stream to condense the remaining portion of the second uncondensed vapor stream via a fourth heat exchanger.

32. The method of claim 31 , further comprising compressing the third uncondensed vapor stream from the fourth heat exchanger and feeding the compressed third uncondensed vapor stream to an upstream side of the air cooler of the second condensing via a compressor.

33. The method of claim 31 , further comprising feeding the second condensed stream of the working fluid exiting via the third separator, a fifth condensed stream exiting via the fourth separator, a sixth condensed stream exiting via the fourth heat exchanger to the second pump.