US4825657A
Expired / Lapsed
US
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Apparatus and method for improved utilization of steam-to-steam reheater drains
Assignee: Siemens Energy Inc
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Filing: 1988-01-28
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Granted: 1989-05-02
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Expires: 2008-01-28
Abstract
Abstract An improved method of heating feedwater streams in a steam-to-steam reheating system for turbine generators is disclosed in which a drain cooler is located to receive the reheater drain and pass it in heat exchange relationship with the discharge of the highest pressure feedwater heater. By use of the drain cooler, heat rate improvement is effected on both single stage reheat plants and two-stage reheat plants. Cycle impairment from moisture carryover in the moisture separator/reheater is also reduced.
Inventors
- 👤 George J. Silvestri, Jr.
- 👤 Paul W. Viscovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:39
CPC Classifications
F; F01; F01K; F01K7/00; F01K7/34; F01K7/40; F01K3/00; F01K3/18; F01K3/26; F01K3/262
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
90 words
In a steam turbine generator employing steam-to-steam reheating having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of said feedwater heaters having a feed inlet and a feed outlet, the improvement comprising: a drain cooler receiving the reheating drain from the reheater and passing said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 2
Dependent Claim
90 words
In a steam turbine generator employing steam-to-steam reheating having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of said feedwater heaters having a feed inlet and a feed outlet, the improvement comprising: a drain cooler receiving the reheating drain from the reheater and passing said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 3
Dependent Claim
36 words
The steam turbine generator of claim 1 wherein the reheater is a two stage reheater, each stage having a reheating drain, and the drain cooler receives the reheating drain from the second of said two stages.
Claim 4
Dependent Claim
29 words
The steam turbine generator of claim 1 wherein the pressure of the reheating drain from the reheater remains substantially the same when it is fed to the drain cooler.
Claim 5
Dependent Claim
16 words
The steam turbine generator of claim 1 wherein the reheating drain from the reheater contains steam.
Claim 6
Dependent Claim
19 words
The steam turbine generator of claim 4 wherein the drain cooler contains a condensing section to condense said steam.
Claim 7
Dependent Claim
89 words
A steam turbine generator employing steam-to-steam reheating having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of said feedwater heaters having a feed inlet and a feed outlet, and further comprising: a drain cooler receiving the reheating drain from the reheater and passing said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 8
Dependent Claim
89 words
A steam turbine generator employing steam-to-steam reheating having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of said feedwater heaters having a feed inlet and a feed outlet, and further comprising: a drain cooler receiving the reheating drain from the reheater and passing said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 9
Dependent Claim
36 words
The steam turbine generator of claim 6 wherein the reheater is a two stage reheater, each stage having a reheating drain, and the drain cooler receives the reheating drain from the second of said two stages.
Claim 10
Dependent Claim
29 words
The steam turbine generator of claim 6 wherein the pressure of the reheating drain from the reheater remains substantially the same when it is fed to the drain cooler.
Claim 11
Dependent Claim
16 words
The steam turbine generator of claim 6 wherein the reheating drain from the reheater contains steam.
Claim 12
Dependent Claim
19 words
The steam turbine generator of claim 9 wherein the drain cooler contains a condensing section to condense said steam.
Claim 13
Dependent Claim
98 words
An improved method of heating feedwater in a steam turbine generator employing steam-to-steam reheating and having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of aid feedwater heaters having a feed inlet and a feed outlet, comprising: using a drain cooler to receive the reheating drain from the reheater and to pass said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 14
Dependent Claim
98 words
An improved method of heating feedwater in a steam turbine generator employing steam-to-steam reheating and having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of aid feedwater heaters having a feed inlet and a feed outlet, comprising: using a drain cooler to receive the reheating drain from the reheater and to pass said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 15
Dependent Claim
34 words
The method of claim 11 Wherein the reheater is a two stage reheater, each stage having a reheating drain, and the drain cooler receives the reheating drain from the second of said two stages.
Claim 16
Dependent Claim
27 words
The method of claim 11 wherein the pressure of the reheating drain from the reheater remains substantially the same when it is fed to the drain cooler.
Claim 17
Dependent Claim
14 words
The method of claim 11 wherein the reheating drain from the reheater contains steam.
Claim 18
Dependent Claim
17 words
The method of claim 14 wherein the drain cooler contains a condensing section to condense said steam.
Claim 19
Independent Claim
100 words
A method of improving the thermal efficiency of an existing steam turbine generator employing steam-to-steam reheating and having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of said feedwater heaters having a feed inlet and a feed outlet, comprising: backfitting a drain cooler to receive the reheating drain from the reheater and to pass said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 20
Independent Claim
100 words
A method of improving the thermal efficiency of an existing steam turbine generator employing steam-to-steam reheating and having a reheater with a reheating drain and having several feedwater heaters connected in series to heat feedwater of increasing pressure, each of said feedwater heaters having a feed inlet and a feed outlet, comprising: backfitting a drain cooler to receive the reheating drain from the reheater and to pass said reheating drain in heat exchange relationship with the feed outlet of said feedwater heater having the highest pressure prior to feeding said reheating drain to said feedwater heater having the highest pressure.
Claim 21
Dependent Claim
34 words
The method of claim 16 wherein the reheater is a two stage reheater, each stage having a reheating drain, and the drain cooler receives the reheating drain from the second of said two stages.
Claim 22
Dependent Claim
27 words
The method of claim 16 wherein the pressure of the reheating drain from the reheater remains substantially the same when it is fed to the drain cooler.
Claim 23
Dependent Claim
14 words
The method of claim 16 wherein the reheating drain from the reheater contains steam.
Claim 24
Dependent Claim
17 words
The method of claim 19 wherein the drain cooler contains a condensing section to condense said steam.
References Cited (Backward Citations)
US3930371A
Cited
US4637350A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |