Patent US2890878A successfully refreshed from Google Patents.
US4466241A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Waste heat recovery boiler
Assignee: Hitachi Ltd
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Filing: 1979-01-17
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Granted: 1984-08-21
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Expires: 1999-01-17
Abstract
Abstract A waste heat recovery boiler for generating steam by utilizing a flue gas discharged from a gas turbine as a heat source comprises an economizer for preheating feedwater by the flue gas, an evaporator for evaporating the preheated feedwater, and a superheater for generating a steam for driving a steam prime mover by heating the evaporated feedwater. The economizer, the evaporator and the superheater are successively arranged in the direction from a downstream side to an upstream side of flue gas passage. The evaporator itself is divided into two sections and an apparatus for removing NOx is provided in a space between the divided two sections of the evaporator in the flue gas passage to remove NOx from the flue gas. An NOx concentration of a flue gas discharged from a combined cycle power plant including the gas turbine can be stably abated at any of full and partial loads.
Inventors
- 👤 Taiji Inui
- 👤 Makoto Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:13
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; F; F22; F22B; F22B1/00; F22B1/02; F22B1/18; F22B1/1807; F22B1/1815; F22B37/00; F22B37/008; F23; F23J; F23J15/00; F23J15/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
133 words
A waste heat recovery boiler comprising a gas passage for conducting a flue gas discharged from a gas turbine, an economizer for preheating feedwater by the flue gas, an evaporator for evaporating the preheated feedwater, and a superheater for generating steam for driving a steam prime mover by heating the evaporated feedwater, the economizer, the evaporator and the superheater being successively arranged in a direction from a downstream side to upstream side of the gas passage, characterized by dividing the evaporator into two sections in a zone in which a flue gas temperature is 300° to 450° C. in the gas passage, and providing an apparatus for removing NO x by a chemical reaction from the flue gas in a space in the gas passage between the two divided sections of the evaporator.
Claim 2
Dependent Claim
133 words
A waste heat recovery boiler comprising a gas passage for conducting a flue gas discharged from a gas turbine, an economizer for preheating feedwater by the flue gas, an evaporator for evaporating the preheated feedwater, and a superheater for generating steam for driving a steam prime mover by heating the evaporated feedwater, the economizer, the evaporator and the superheater being successively arranged in a direction from a downstream side to upstream side of the gas passage, characterized by dividing the evaporator into two sections in a zone in which a flue gas temperature is 300° to 450° C. in the gas passage, and providing an apparatus for removing NO x by a chemical reaction from the flue gas in a space in the gas passage between the two divided sections of the evaporator.
Claim 3
Dependent Claim
30 words
A waste heat recovery boiler according to claim 1, wherein a device for forcedly circulating feedwater is provided to transfer the feedwater between the two divided sections of the evaporator.
Claim 4
Dependent Claim
53 words
A waste heat recovery boiler according to claim 1, wherein the apparatus for removing NO x by a chemical reaction comprises a reducing agent injection nozzle for supplying an appropriate amount of ammonia into the flue gas, and a catalyst bed provided in the gas, passage at a downstream side of the nozzle.
Claim 5
Dependent Claim
42 words
A waste heat recovery boiler according to claim 1, wherein the apparatus for removing NO x by a chemical reaction comprises at least a catalyst bed, and the catalyst bed is divided into a plurality of compartments by a plurality of ducts.
Claim 6
Dependent Claim
43 words
A waste heat recovery boiler according to claim 4, wherein the ducts are arranged in the same direction as that of the gas passage, and the catalyst bed is provided on flat levels in the same direction as that of the gas passage.
Claim 7
Dependent Claim
32 words
A waste heat recovery boiler according to claim 4, wherein a plurality of the ducts are each provided with devices for controlling flow rates of the flue gas to the respective ducts.
Claim 8
Dependent Claim
148 words
A waste heat recovery boiler comprising a gas passage means for conducting a flue gas discharged from a gas turbine to a venting stack, and evarporator means for evaporating preheated feedwater of the boiler, characterized in that the evaporator means is disposed in a zone of the gas passage means in which a temperature of the flue gas is between 300° to 450°, the evaporator means includes a first evaporator section and a second evaporator section, said second evaporator section being disposed at a position spaced from and downstream of the first evaporator section, as viewed in a flow direction of the flue gas through the gas passage means, and in that means are disposed in the gas passage means in a space between the first and second evaporator sections for removing NO x by a chemical reaction from the flue gas flowing through the gas passage means.
Claim 9
Dependent Claim
148 words
A waste heat recovery boiler comprising a gas passage means for conducting a flue gas discharged from a gas turbine to a venting stack, and evarporator means for evaporating preheated feedwater of the boiler, characterized in that the evaporator means is disposed in a zone of the gas passage means in which a temperature of the flue gas is between 300° to 450°, the evaporator means includes a first evaporator section and a second evaporator section, said second evaporator section being disposed at a position spaced from and downstream of the first evaporator section, as viewed in a flow direction of the flue gas through the gas passage means, and in that means are disposed in the gas passage means in a space between the first and second evaporator sections for removing NO x by a chemical reaction from the flue gas flowing through the gas passage means.
Claim 10
Dependent Claim
53 words
A waste heat recovery boiler according to claim 7, characterized in that said means for removing NO x by a chemical reaction from the flue gas includes a catalyst means disposed between the first and second evaporator sections for removing the NO x from the flue gas passed through the gas passage means.
Claim 11
Dependent Claim
43 words
A waste heat recovery boiler according to claim 7 or 8, characterized in that the means for removing the NO x by a chemical reaction from the flue gas includes an injection nozzle means for injecting a reducing agent into the flue gas.
Claim 12
Dependent Claim
27 words
A waste heat recovery boiler according to claim 8, characterized in that means are provided for controlling a flow of the flue gas through the catalyst means.
Claim 13
Dependent Claim
25 words
A waste heat recovery boiler according to claim 9, characterized in that means are provided for transferring feedwater between the first and second evaporator sections.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-21 | 1988-02-20 | 1988-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-21 | 1992-02-20 | 1992-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-21 | 1996-02-20 | 1996-08-21 | $7700.00 | Window Closed / Lapsed |