Turbo-alternator-compressor design for supercritical high density working fluids

• US 8,397,506 B1
• Filed: 06/03/2009
• Issued: 03/19/2013
• Est. Priority Date: 06/03/2009
• Status: Active Grant

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Wright, Steven A., Fuller, Robert L.
• Primary Examiner(s): NGUYEN, HOANG M
• Application Number:
  US12/477,259
• Time in Patent Office: 1,385 Days
• Field of Search: 606/43, 606/45, 606/052, 606/50, 606/82, 415110-113
• US Class Current: 60/643
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F01D 3/00 Machines or engines with axial-thrust balancing effected by working-fluid
• CPC Class Codes: F01K 25/08 using special vapours
• CPC Class Codes: F01K 7/32 the engines using steam of critical or overcritical pressure
• CPC Class Codes: F02C 1/10 Closed cycles

Abstract

Techniques for generating power are provided. Such techniques involve a thermodynamic system including a housing, a turbine positioned in a turbine cavity of the housing, a compressor positioned in a compressor cavity of the housing, and an alternator positioned in a rotor cavity between the turbine and compressor cavities. The compressor has a high-pressure face facing an inlet of the compressor cavity and a low-pressure face on an opposite side thereof. The alternator has a rotor shaft operatively connected to the turbine and compressor, and is supported in the housing by bearings. Ridges extending from the low-pressure face of the compressor may be provided for balancing thrust across the compressor. Seals may be positioned about the alternator for selectively leaking fluid into the rotor cavity to reduce the temperature therein.

Claims

1. A thermodynamic system for generating power from a supercritical working fluid, comprising:

a housing;

a turbine positioned in a turbine cavity of the housing;

a compressor positioned in a compressor cavity of the housing, the compressor having a high-pressure face facing an inlet of the compressor cavity and a low-pressure face on an opposite side thereof; and

an alternator positioned in a rotor cavity between the turbine and compressor cavities, the alternator having a rotor shaft operatively connected to the turbine and compressor, the alternator supported in the housing by bearings;

wherein the compressor has a plurality of ridges extending from the low-pressure face thereof for pumping the supercritical working fluid as it passes over the compressor whereby a pressure differential between the high-pressure face and the low-pressure face is reduced such that thrust is balanced across the compressor.

2. The thermodynamic system of claim 1, wherein the turbine has a plurality of cutouts therein for manipulating the supercritical working fluid as it passes therethrough whereby thrust is balanced across the turbine.

3. The thermodynamic system of claim 1, further comprising a plurality of seals positioned about the alternator for selectively isolating the rotor cavity from the turbine and compressor cavities whereby the supercritical working fluid is selectively leaked into the rotor cavity to reduce the temperature therein.

4. The thermodynamic system of claim 3, wherein the seals are selected from the group consisting of dry lift off, brush, windback, abradable, hole pattern and combinations thereof.

5. The thermodynamic system of claim 1, further comprising a fluid circuit for circulating the supercritical working fluid through the thermodynamic system.

6. The thermodynamic system of claim 5, wherein the fluid circuit comprises at least one selected from the group consisting of a heater, a chiller, a gas booster, a drain, at least one valve, at least one fluid measurer and combinations thereof.

7. The thermodynamic system of claim 1, wherein the bearings are selected from the group consisting of thrust, journal, gas foil, ball, magnetic and tilt bearings.

8. The thermodynamic system of claim 1, further comprising a pump operatively connected to the rotor cavity for selectively lowering pressure therein.

9. The thermodynamic system of claim 1, wherein the supercritical working fluid comprises at least a portion of one selected from the group consisting of an inorganic compound, a noble gas, an olefin, a fuel, a refrigerant, and combinations thereof.

10. The thermodynamic system of claim 1, wherein the supercritical working fluid passes over the compressor at a pressure just above a critical pressure of the supercritical working fluid.

11. A thermodynamic system for generating power from a supercritical working fluid, comprising:

a housing;

a turbine positioned in a turbine cavity of the housing;

a compressor positioned in a compressor cavity of the housing;

an alternator positioned in a rotor cavity between the turbine and compressor, the alternator having a rotor shaft operatively connected to the turbine and compressor, the alternator supported in the housing by bearings; and

a plurality of seals positioned about the alternator for selectively isolating the rotor cavity from the turbine and compressor cavities whereby the supercritical working fluid is selectively leaked into the rotor cavity to reduce the temperature therein.

12. The thermodynamic system of claim 11, wherein the compressor has a high-pressure face facing an inlet of the compressor cavity and a low-pressure face opposite thereto, the system further comprising a plurality of ridges extending from the low-pressure face of the compressor for pumping the supercritical working fluid as it passes over the compressor whereby a pressure differential between the high-pressure face and the low-pressure face is reduced such that thrust is balanced across the compressor.

13. The thermodynamic system of claim 12, wherein the turbine has a plurality of cutouts therein for manipulating the supercritical working fluid as it passes therethrough whereby thrust is balanced across the turbine.

14. The thermodynamic system of claim 11, wherein the bearings are selected from the group consisting of thrust, journal, gas foil, ball, magnetic and tilt bearings.

15. The thermodynamic system of claim 11, wherein the seals are selected from the group consisting of dry lift off, brush, windback, abradable, hole pattern and combinations thereof.

16. The thermodynamic system of claim 11, further comprising a pump operatively connected to the rotor cavity for selectively lowering pressure therein.

17. The thermodynamic system of claim 11, wherein the supercritical working fluid comprises at least a portion of one selected from the group consisting of an inorganic compound, a noble gas, an olefin, a fuel, a refrigerant, and combinations thereof.

18. The thermodynamic system of claim 11, wherein the supercritical working fluid enters the compressor cavity at a pressure just above a critical pressure of the supercritical working fluid.

19. The thermodynamic system of claim 11, further comprising a fluid circuit for circulating the supercritical working fluid through the system.

20. The thermodynamic system of claim 19, wherein the fluid circuit comprises at least one selected from the group consisting of a heater, a chiller, a gas booster, a drain, at least one valve, at least one fluid measurer and combinations thereof.

21. A method of generating power from a supercritical working fluid, comprising:

providing a thermodynamic system, the system comprising

a housing;

a turbine positioned in a turbine cavity of the housing;

a compressor positioned in a compressor cavity of the housing, the compressor having a high-pressure face facing an inlet of the compressor cavity and a low-pressure face on an opposite side thereof, the low-pressure face having a plurality of ridges; and

an alternator positioned in a rotor cavity between the turbine and compressor cavities, the alternator having a rotor shaft operatively connected to the turbine and compressor, the alternator supported in the housing by bearings;

compressing a supercritical working fluid by passing the working fluid across the compressor;

generating a power output by passing the compressed supercritical working fluid across the turbine; and

balancing thrust across the compressor by pumping the supercritical working fluid with the plurality of ridges as the supercritical working fluid passes over the compressor.

22. The method of claim 21, further comprising balancing thrust across the turbine by manipulating the supercritical working fluid as it passes thereby.

23. The method of claim 21, further comprising selectively isolating the rotor cavity from the turbine and compressor cavities by selectively leaking a portion of the supercritical working fluid past a plurality of seals and into the rotor cavity.

24. The method of claim 21, further comprising recirculating the supercritical working fluid from the turbine back to the compressor.

25. The method of claim 21, further comprising measuring parameters of the supercritical working fluid.

26. The method of claim 21, further comprising releasing at least a portion of the supercritical working fluid from the rotor cavity.

27. The method of claim 26, further comprising re-circulating at least a portion of the supercritical working fluid from the rotor cavity to the compressor.

28. The method of claim 21, further comprising pumping the supercritical working fluid released from the rotor cavity.

29. The method of claim 21, further comprising selectively manipulating the supercritical working fluid as it passes through the thermodynamic system.