Gas turbine generator set

• US 8,875,483 B2
• Filed: 03/02/2012
• Issued: 11/04/2014
• Est. Priority Date: 09/03/2009
• Status: Expired due to Fees

• Current Assignee: Ansaldo Energia Switzerland AG (Ansaldo Energia SPA)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Wettstein, Hans
• Primary Examiner(s): KIM, CRAIG SANG
• Application Number:
  US13/410,328
• Publication Number:
  US 20120210723A1
• Time in Patent Office: 977 Days
• Field of Search: 60/395, 60/395.2, 608/05, 608/06
• US Class Current: 60/39.52
• CPC Class Codes: F02C 3/34 with recycling of part of the working fluid, i.e. semi-closed cycles with combustion products in the closed part of the cycle
• CPC Class Codes: F02C 6/18 using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10
• CPC Class Codes: F02C 7/18 the medium being gaseous, e.g. air F02C7/125 takes precedence
• CPC Class Codes: F05D 2270/082 with as little NOx as possible

Abstract

A gas turbine generator set includes a compressor unit including at least one compressor, at least one generator and at least one combustion chamber. Exhaust gases from at least one turbine are recirculated for a further thermal utilization. At least one cooling fluid compressor is configured to compress a cooling fluid including at least one of fresh air and a portion of the recirculated exhaust gases for a cooling of thermally loaded parts.

Claims

1. A gas turbine generator set, comprising:

a compressor unit including a compressor;

a generator;

a combustion chamber;

a turbine, configured such that an exhaust gas from the turbine is recirculated for a further thermal utilization;

a cooling fluid compressor;

a cooling fluid filter; and

a compressor unit filter,

wherein the cooling fluid filter is finer than the compressor unit filter,

wherein the cooling fluid compressor is configured to be supplied with a cooling fluid including (i) fresh air and (ii) a portion of the exhaust gas from the turbine, and

configured such that the cooling fluid, compressed in the cooling fluid compressor, cools a thermally loaded part of the turbine.

2. The gas turbine generator set as recited in claim 1, wherein the cooling fluid compressor is configured to control a mass flow.

3. The gas turbine generator set as recited in claim 2, wherein the mass flow is controlled by

an adjustable rotation speed,

at least one row of variable inlet guide vanes, or

an adjustable rotation speed and at least one row of variable inlet guide vanes.

4. The gas turbine generator set as recited in claim 1,

wherein the fluid entering the compressor unit is not filtered.

5. The gas turbine generator set as recited in claim 1, wherein the compressor unit filter causes a pressure drop of less than 8 millibars.

6. The gas turbine generator set as recited in claim 1, further comprising:

a cooling system including passages or film cooling holes, each having a clear width less than 0.6 mm.

7. The gas turbine generator set as recited in claim 1, further comprising:

a second combustion chamber; and

a second turbine,

wherein the combustion chamber is a first combustion chamber,

wherein the turbine is a first turbine,

wherein the first combustion chamber is disposed downstream of the compressor unit,

wherein the first turbine is disposed downstream of the first combustion chamber,

wherein the second combustion chamber is disposed downstream of the first turbine,

wherein the second turbine is disposed downstream of the second combustion chamber, and

wherein the first and the second turbines are thermodynamically interconnected.

8. The gas turbine generator set as recited in claim 1, further comprising;

a heat recovery steam generator configured to receive the exhaust gas.

9. The gas turbine generator set as recited in claim 8, configured such that the exhaust gas is extracted on a discharge side of the heat recovery steam generator.

10. The gas turbine generator set as recited in claim 9, further comprising:

a recooler/condenser,

wherein the recooler/condenser is disposed upstream of the compressor unit and configured to receive the exhaust gas.

11. The gas turbine generator set as recited in claim 1, further comprising:

a recirculation line for the exhaust gas, and

a fan disposed in the recirculation line.

12. The gas turbine generator set as recited in claim 11, wherein the fan is configured to control a recirculation rate of the exhaust gas.

13. The gas turbine generator set as recited in claim 1, further comprising:

a cooling fluid line branching from the cooling fluid compressor to the thermally loaded part to be cooled.

14. The gas turbine generator set as recited in claim 13, wherein the cooling fluid line includes a shut-off element.

15. The gas turbine generator set as recited in claim 14, wherein the shut-off element includes a check valve.

16. The gas turbine generator set as recited in claim 1, further comprising:

a plurality of cooling fluid lines branching from the cooling fluid compressor to the thermally loaded part to be cooled.

17. The gas turbine generator set as recited in claim 16, wherein each of the plurality of cooling fluid lines is at a different pressure.

18. The gas turbine generator set as recited in claim 1, wherein the cooling fluid compressor includes a intercooler.

19. The gas turbine generator set as recited in claim 18, wherein a mass flow of the cooling fluid compressor is configured to be reduced in proportion to a reduced discharge temperature of the cooling fluid compressor.

20. The gas turbine generator set as recited In claim 1, wherein the cooling fluid compressor is configured to be driven by a shaft of the gas turbine generator set directly.

21. The gas turbine generator set as recited in claim 1, further comprising:

an electric motor, configured to drive the cooling fluid compressor, and operationally connected to the generator so as to provide a power supply in an event of failure of an external network connection.

22. The gas turbine generator set as recited in claim 10, wherein a portion of the recirculated exhaust gas is branched downstream of the recooler/condenser and upstream of the cooling fluid compressor.

23. The gas turbine generator set as recited in claim 1, wherein the cooling fluid compressor includes a plurality of cooling fluid compressors configured to be operated sequentially or in parallel.

24. The gas turbine generator set as recited in claim 7, wherein the second combustion chamber includes a self-igniting combustion chamber.

25. The gas turbine generator set as recited in claim 7, wherein the first and the second turbines are disposed on a common rotor shaft.

26. The gas turbine generator set as recited in claim 1, wherein the compressor unit and the cooling fluid compressor are configured to be operated in a high fogging mode, in which an inducted air comprises water.

27. The gas turbine generator set as recited in claim 26, wherein the high fogging mode includes operating the compressor unit and the cooling fluid compressor with at least 0.5% water quantity of an inducted air volume.

28. The gas turbine generator set as recited in claim 1, wherein the cooling fluid compressor is configured to be driven by a shaft of the gas turbine generator set via a gearbox.

29. A method for operating a gas turbine generator set including a compressor unit comprising a compressor, a generator, a combustion chamber, a turbine, a cooling fluid compressor, a cooling fluid filter, and a compressor unit filter, the method comprising:

filtering inducted air fed into the compressor unit with the compressor unit filter;

recirculating an exhaust gas from the turbine for a further thermal utilization, the recirculating including;

supplying the cooling fluid compressor, through the cooling unit filter, with a cooling fluid including fresh air and a portion of the exhaust gas;

compressing the cooling fluid in the cooling fluid compressor, to obtain a compressed cooling fluid; and

supplying the compressed cooling fluid to a thermally loaded part, to cool the thermally loaded part with the supplied compressed cooling fluid,

wherein the thermally loaded part exposed to hot gases downstream of the combustion chamber is preoxidized, and

wherein the cooling fluid filter is finer than the compressor unit filter.

30. The method as recited in claim 29, wherein the recirculating further includes periodically interrupting the recirculating by phasing fresh air into the gas turbine generator set so as to regenerate an oxide layer of the thermally loaded part.

31. The method as recited in claim 29, wherein a portion of the cooling fluid includes fluid from the main compressor, and

wherein the gas turbine generator set is operable at a partial load in an event of a failure of the cooling fluid compressor.

32. The method as recited in claim 29, further comprising:

connecting waste heat of an intercooler of the cooling fluid compressor into a bottoming cycle.

33. The method as recited in claim 29, further comprising:

automatically injecting a substitute cooling medium in the gas turbine generator set in an event of a failure of the cooling fluid compressor, and

isolating the failed cooling fluid compressor using a check valve.

34. The method as recited in claim 29, wherein the cooling fluid compressor includes a first blade having a lower gas bending stress than a second blade of the compressor unit.

35. The method as recited in claim 29, further comprising

controlling the cooling fluid compressor so as to keep the thermally loaded part cooled with the cooling fluid at an almost constant metal temperature within a wide load range so as to prevent a shock-like cooling.

36. The method as recited in claim 29, wherein a mass flow of the cooling fluid compressor is greater than a cooling mass flow required for the cooling of the thermally loaded part, and

wherein a portion of the mass flow of the cooling fluid compressor not required for cooling is introduced between the combustion chamber and the turbine.

37. The method as recited in claim 29, further comprising:

operating the combustion chamber near-stoichiometrically using a fuel having a low calorific value.