US4473537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ammonia control system for NOx emission control for gas turbine exhaust
Assignee: General Electric Co
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Filing: 1982-12-27
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Granted: 1984-09-25
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Expires: 2002-12-27
Abstract
Abstract A steam and gas turbine combined cycle plant STAG* employs a catalyst in a heat recovery steam generator to react injected ammonia with NO x from the combustor of the gas turbine to reduce atmospheric emission of NO x from the system. Rapid control of ammonia injection is achieved using a prediction of the NO x being generated in dependence upon the operating conditions of the combustor. A trimming signal from a measurement of NO x being emitted from the heat recovery steam generator downstream of the catalyst is employed to complete the NO x control loop. Compensation is provided to relate the measured NO x downstream of the catalyst with the NO x in the output of the gas turbine taking into account the catalyst efficiency.
Inventors
- 👤 Mark R. Ford, Jr.
- 👤 Brian G. Colozzi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:52
CPC Classifications
F; F02; F02C; F02C3/00; F02C3/20; F02C3/30; B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8696; G; G05; G05B; G05B13/00; G05B13/02; G05B13/04; G05B13/048; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02E; Y02E20/00; Y02E20/16; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692; Y10T436/178459; Y10T436/179228
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
229 words
An ammonia control system for controlling a flow of ammonia into an exhaust of a fuel combustion apparatus to enable reaction of NO x in said exhaust with said ammonia in a catalyst for reduction of NO x effluent into the atmosphere, including a controller effective to produce a predicted NO x signal related to parameters in said combustion apparatus and at least one NO x setpoint signal representing a desired NO x condition downstream of said catalyst, a NO x analyzer producing a measured NO x signal related to a relative volume concentration of NO x downstream of said catalyst, comprising: means for converting said measured NO x signal in terms of relative volume concentration into a NO x flow rate in terms of moles of NO x per unit time; said at least one NO x setpoint signal being in terms of moles of NO x per unit time; means for differencing the converted measured NO x flow rate and the NO x setpoint signal to produce a NO x error signal; means for producing a mole ratio signal of ammonia to NO x in response to said NO x error signal; means for multiplying said mole ratio signal by said predicted NO x signal to produce an ammonia command signal; and an ammonia supply responsive to said ammonia command signal for injecting ammonia into said exhaust.
Claim 2
Dependent Claim
229 words
An ammonia control system for controlling a flow of ammonia into an exhaust of a fuel combustion apparatus to enable reaction of NO x in said exhaust with said ammonia in a catalyst for reduction of NO x effluent into the atmosphere, including a controller effective to produce a predicted NO x signal related to parameters in said combustion apparatus and at least one NO x setpoint signal representing a desired NO x condition downstream of said catalyst, a NO x analyzer producing a measured NO x signal related to a relative volume concentration of NO x downstream of said catalyst, comprising: means for converting said measured NO x signal in terms of relative volume concentration into a NO x flow rate in terms of moles of NO x per unit time; said at least one NO x setpoint signal being in terms of moles of NO x per unit time; means for differencing the converted measured NO x flow rate and the NO x setpoint signal to produce a NO x error signal; means for producing a mole ratio signal of ammonia to NO x in response to said NO x error signal; means for multiplying said mole ratio signal by said predicted NO x signal to produce an ammonia command signal; and an ammonia supply responsive to said ammonia command signal for injecting ammonia into said exhaust.
Claim 3
Dependent Claim
141 words
An ammonia control system according to claim 1, wherein said at least one NO x setpoint signal includes a first setpoint signal in terms of NO x relative volume concentration and a second setpoint signal in terms of moles of NO x per unit time, further comprising: means for decorrecting said first setpoint signal for an amount of oxygen in said effluent to produce a decorrected signal; means for time aligning a flow rate in said combustion apparatus with a response time of a NO x analyzer device to produce a time-aligned flow rate signal; means for multiplying said decorrected signal by said time-aligned flow rate signal to produce a corrected first setpoint signal; and a setpoint selector effective to apply whichever one of said corrected first setpoint signal and said second setpoint signal is larger to said means for differencing.
Claim 4
Dependent Claim
64 words
An ammonia control system according to claim 2, wherein said means for time aligning includes a time delay having a delay time equal to a difference between a transport time of gas flow from a point where said flow rate is measured to a point where a sample for said NO x is taken and a response time of said NO x analyzer device.
Claim 5
Dependent Claim
47 words
An ammonia control system according to claim 1, wherein said means for producing a mole ratio signal includes a non-linear amplifier having an output proportional to a mole ratio of ammonia to NO x before reaction in said catalyst in response to said measured NO x signal.
Claim 6
Dependent Claim
43 words
An ammonia control system according to claim 1, wherein said means for producing a mole ratio signal includes a temperature corrector effective to modulate said mole ratio signal according to an efficiency of said catalyst with respect to a temperature of said catalyst.
Claim 7
Independent Claim
201 words
A method for controlling a flow of ammonia into an exhaust of a fuel combustion apparatus to enable reaction of NO x in said exhaust with said ammonia in a catalyst for reduction of NO x effluent into the atmosphere, said apparatus being effective to produce a predicted NO x signal related to parameters in said combustion apparatus and at least one NO x setpoint signal representing a desired NO x condition downstream of said catalyst, a NO x analyzer producing a measured NO x signal related to a relative volume concentration of NO x downstream of said catalyst, comprising the steps of: converting said measured NO x signal in terms of relative volume concentration into a NO x flow rate in terms of moles of NO x per unit time; differencing the converted measured NO x flow rate and the NO x setpoint signal to produce a NO x error signal; producing a mole ratio signal of ammonia to NO x in response to said NO x error signal; multiplying said mole ratio signal by said predicted NO x signal to produce an ammonia command signal; and injecting said ammonia into said exhaust in response to said ammonia command signal.
Claim 8
Independent Claim
201 words
A method for controlling a flow of ammonia into an exhaust of a fuel combustion apparatus to enable reaction of NO x in said exhaust with said ammonia in a catalyst for reduction of NO x effluent into the atmosphere, said apparatus being effective to produce a predicted NO x signal related to parameters in said combustion apparatus and at least one NO x setpoint signal representing a desired NO x condition downstream of said catalyst, a NO x analyzer producing a measured NO x signal related to a relative volume concentration of NO x downstream of said catalyst, comprising the steps of: converting said measured NO x signal in terms of relative volume concentration into a NO x flow rate in terms of moles of NO x per unit time; differencing the converted measured NO x flow rate and the NO x setpoint signal to produce a NO x error signal; producing a mole ratio signal of ammonia to NO x in response to said NO x error signal; multiplying said mole ratio signal by said predicted NO x signal to produce an ammonia command signal; and injecting said ammonia into said exhaust in response to said ammonia command signal.
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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) | 1987-09-25 | 1988-03-26 | 1988-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-25 | 1992-03-26 | 1992-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-25 | 1996-03-26 | 1996-09-25 | $7700.00 | Window Closed / Lapsed |