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US6141952A
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Method of operating a combined-cycle power plant
Assignee: Alstom SA
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Filing: 1998-09-18
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Granted: 2000-11-07
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Expires: 2018-09-18
Abstract
Abstract In a method of operating a combined-cycle plant, valves (21) acting upstream of a high-pressure steam turbine (12) are completely closed in the event of load shedding. The gas-turbine group (A+8) is uncoupled from an intermediate-pressure/low-pressure steam turbine (11) in such a way that the gas-turbine group can go into island mode. In this case, the speed of the uncoupled steam turbine (11) is not greater than the speed of the gas-turbine group (A+8), and steam (16) in the flow path of a reheater (10a) belonging to the heat-recovery steam generator (10) expands freely through the intermediate-pressure/low-pressure steam turbine (11), in the course of which this expansion does not cause the speed of the gas-turbine group (A+8) to exceed its protective speed.
Inventors
- 👤 Rolf Bachmann
- 👤 Fredy Hausermann
- 👤 Peter Muller
- 👤 Gerhard Weiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:46
CPC Classifications
F; F01; F01K; F01K23/00; F01K23/02; F01K23/06; F01K23/10; F01K23/101; Y; Y02; Y02E; Y02E20/00; Y02E20/16
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
159 words
A method of operating a combined-cycle plant, essentially comprising a gas turbine, at least one generator and a steam circuit, this steam circuit essentially comprising a heat-recovery steam generator, at least one low-pressure and/or intermediate-pressure steam turbine and a high-pressure steam turbine, wherein, in the event of load shedding, at least one valve acting upstream of the high-pressure steam turbine is closed, wherein the gas turbine and the generator are uncoupled from the low-pressure and/or intermediate-pressure steam turbine in such a way that gas turbine and the generator go into isolated operation, wherein the speed of the uncoupled steam turbine is not greater than the speed of the gas turbine and the generator, wherein steam in the flow path of a reheater belonging to the heat-recovery steam generator expands freely through the low-pressure and/or intermediate-pressure steam turbine, and wherein this expansion does not cause the speed of the gas turbine and of the generator to exceed their protective speed.
Claim 2
Independent Claim
159 words
A method of operating a combined-cycle plant, essentially comprising a gas turbine, at least one generator and a steam circuit, this steam circuit essentially comprising a heat-recovery steam generator, at least one low-pressure and/or intermediate-pressure steam turbine and a high-pressure steam turbine, wherein, in the event of load shedding, at least one valve acting upstream of the high-pressure steam turbine is closed, wherein the gas turbine and the generator are uncoupled from the low-pressure and/or intermediate-pressure steam turbine in such a way that gas turbine and the generator go into isolated operation, wherein the speed of the uncoupled steam turbine is not greater than the speed of the gas turbine and the generator, wherein steam in the flow path of a reheater belonging to the heat-recovery steam generator expands freely through the low-pressure and/or intermediate-pressure steam turbine, and wherein this expansion does not cause the speed of the gas turbine and of the generator to exceed their protective speed.
Claim 3
Dependent Claim
25 words
The method as claimed in claim 1, wherein the high-pressure steam turbine and the low-pressure and/or intermediate-pressure steam turbine are bypassed by a steam-carrying line.
Claim 4
Dependent Claim
24 words
The method as claimed in claim 2, wherein the steam in the bypass line is directed into a condenser belonging to the steam circuit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-11-07 | 2004-05-08 | 2004-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-11-07 | 2008-05-08 | 2008-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-11-07 | 2012-05-08 | 2012-11-07 | $7700.00 | Window Closed / Lapsed |