US4896496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single pressure steam bottoming cycle for gas turbines combined cycle
Assignee: Stone and Webster Engineering Corp
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Filing: 1988-07-25
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Granted: 1990-01-30
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Expires: 2008-07-25
Abstract
Abstract A process for recapturing waste heat from a gas turbine at a single pressure to drive both a high pressure-high temperature steam turbine and a low pressure steam turbine. By placing the reheat coil of the low pressure steam turbine in a common vessel with a portion of the economizer coil (used to preheat the steam for the high pressure-high temperature steam turbine), maximum heat recovery from the exhaust gases of the gas turbine is obtained at a single pressure.
Inventors
- 👤 Nicholas Zervos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:52
CPC Classifications
F; F01; F01K; F01K23/00; F01K23/02; F01K23/06; F01K23/10; F01K23/103; Y; Y02; Y02E; Y02E20/00; Y02E20/16
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
203 words
A process for recapturing waste heat from the exhaust of a gas turbine to drive a high pressure-high temperature steam turbine and a low pressure steam turbine comprising the steps of: (a) delivering the exhaust of the gas turbine to the hot side of an economizer-reheater apparatus; (b) delivering a heated stream of feedwater and recycled condensate through the cold side of the economizer-reheater apparatus in an indirect heat exchange relationship with the gas turbine exhaust on the hot side of the economizer-reheater apparatus to elevate the temperature of the feedwater and recycled condensate to a temperature below the pinch point of the boiler; (c) delivering the discharge from the high pressure-high temperature steam turbine through the economizer-reheater apparatus in an indirect heat exchange relationship with the gas turbine exhaust on the hot side of the economizer-reheater apparatus; (d) driving the high pressure-high temperature steam turbine with the discharged stream of feedwater and recycled condensate which is heated to a temperature below the pinch point of the boiler by the economizer-reheater apparatus; and (e) driving the low pressure steam turbine with the discharged stream of the high pressure-high temperature steam turbine reheated below the pinch point of the boiler by the economizer-reheater apparatus.
Claim 2
Dependent Claim
203 words
A process for recapturing waste heat from the exhaust of a gas turbine to drive a high pressure-high temperature steam turbine and a low pressure steam turbine comprising the steps of: (a) delivering the exhaust of the gas turbine to the hot side of an economizer-reheater apparatus; (b) delivering a heated stream of feedwater and recycled condensate through the cold side of the economizer-reheater apparatus in an indirect heat exchange relationship with the gas turbine exhaust on the hot side of the economizer-reheater apparatus to elevate the temperature of the feedwater and recycled condensate to a temperature below the pinch point of the boiler; (c) delivering the discharge from the high pressure-high temperature steam turbine through the economizer-reheater apparatus in an indirect heat exchange relationship with the gas turbine exhaust on the hot side of the economizer-reheater apparatus; (d) driving the high pressure-high temperature steam turbine with the discharged stream of feedwater and recycled condensate which is heated to a temperature below the pinch point of the boiler by the economizer-reheater apparatus; and (e) driving the low pressure steam turbine with the discharged stream of the high pressure-high temperature steam turbine reheated below the pinch point of the boiler by the economizer-reheater apparatus.
Claim 3
Dependent Claim
45 words
A process in claim 1 further comprising the steps of delivering the heated stream of feedwater and recycled condensate from the economizer-reheater apparatus to a high pressure boiler before delivery to a high pressure-high temperature steam turbine and converting said steam to high pressure steam.
Claim 4
Dependent Claim
43 words
A process as in claim 2 further comprising the steps of delivering the high pressure steam from the high pressure boiler, to a superheater before delivery to a high pressure-high temperature steam turbine and further heating the high pressure steam in the superheater.
Claim 5
Dependent Claim
30 words
A process as in claim 1 further comprising the step of heating the stream of feedwater and recycled condensate in a low temperature preheater before delivery to an economizer-reheater apparatus.
Claim 6
Dependent Claim
54 words
A process as in claim 4 further comprising the step of delivering the heated stream of feedwater and recycled condensate from the low temperature preheater to a deaerator before delivery to an economizer-reheater apparatus and further heating said stream in the deaerator by indirect heat exchange with the exhaust from the gas turbine exhaust.
Claim 7
Dependent Claim
27 words
A process as in claim 3 wherein the high pressure steam is heated in the superheater by indirect heat exchange with the exhaust from the gas turbine.
Claim 8
Dependent Claim
30 words
A process as in claim 5 wherein the flow of feedwater and recycled condensate is heated in the low temperature preheater by indirect heat exchange with the gas turbine exhaust.
Claim 9
Dependent Claim
35 words
A process as in claim 1 wherein the fluid in the reheater coil is reheated through about the temperature range and by the same fluid as the fluid as the fluid in the economizer coil.
Claim 10
Dependent Claim
147 words
A process as in claim 1 wherein the temperature of the gas turbine exhaust entering the hot side of the economizer-reheater apparatus is 500° F. to 800° F.; the temperature of the feedwater-recycled condensate entering a cold side of the economizer reheater apparatus is 180° F. to 350° F.; the temperature of the discharge from the high pressure-high temperature steam turbine entering another cold side of the economizer-reheater apparatus is 250° F. to 400° F.; the temperature of the gas turbine exhaust discharged from the hot side of the economizer-reheater apparatus is 250° F. to 500° F.; the temperature of the feedwater-recycled condensate discharged from the cold side of the economizer-reheater apparatus is 500° F. to 700° F.; and the temperature of the discharge from the high pressure-high temperature steam turbine discharged from the other cold side of the economizer-reheater apparatus is 400° F. to 800° F.
Claim 11
Dependent Claim
94 words
A process as in claim 2 wherein the temperature of the feedwater and recycled condensate stream entering the cold side of the high pressure boiler is 500° F. to 700° F.; the temperature of the gas turbine exhaust entering the hot side of the high pressure boiler is 700° F. to 1000° F.; the discharge of the feedwater and recycled condensate stream, converted to high pressure steam, is 500° F. to 700° F.; and the gas turbine exhaust discharged from the hot side of the high pressure boiler is 600° F. to 900° F.
Claim 12
Dependent Claim
90 words
A process as in claim 6 wherein the temperature of the gas turbine exhaust entering the hot side of the superheater is 850° F. to 1400° F.; the temperature of the high pressure steam entering the cold side of the superheater is 500° F. to 700° F.; the temperature of the gas turbine exhaust discharged from the hot side of the superheater is 750° F. to 1050° F.; and the temperature of the high pressure steam discharged to the high pressure-high temperature steam turbine is 750° F. to 1050° F.
Claim 13
Dependent Claim
156 words
A process as in claim 7 wherein the temperature of the gas turbine exhaust entering the hot side of the preheater is 250° F. to 500° F.; the temperature of the feedwater-recycled condensate entering the cold side of the preheater is 40° F. to 150° F.; the temperature of the gas turbine exhaust discharged from the preheater is 100° F. to 400° F.; and the temperature of the feedwater-recycled condensate discharged to the deaerator is 40° F. to 250° F.; the temperature of the gas turbine exhaust entering the hot side of the deaerator is 250° F. to 500° F.; the temperature of the feedwater-recycled condensate entering the cold side of the deaerator is 40° F. to 250° F.; the temperature of the gas turbine exhaust discharged to the low temperature preheater is 250° F. to 500° F.; and the temperature of the feedwater-recycled condensate discharged to the economizer-reheater apparatus is 180° F. to 350° F.
Claim 14
Dependent Claim
23 words
A process as in claim 6 further comprising the addition of supplementary heat to the gas turbine exhaust before delivery to the superheater.
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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) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |