Patent US5280756A successfully refreshed from Google Patents.
US5280756A
Expired / Lapsed
US
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NOx Emissions advisor and automation system
Assignee: Stone and Webster Engineering Corp
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Filing: 1993-02-26
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Granted: 1994-01-25
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Expires: 2013-02-26
Abstract
Abstract A method and system for controlling and providing guidance in reducing the level of NO x emissions based on controllable combustion parameters and model calculations while maintaining satisfactory plant performance and not causing other harmful consequences to the furnace. To implement such a system, boiler control values of flow, pressure, temperature, valve and damper positions in addition to emission sensors for data associated with the production of NO x , O 2 , CO, unburned carbon and fuel. This information is received from standard sensors located throughout a boiler which are connected either to a distributed control system (DCS), or another data acquisition system which is time coordinated with the DCS. The DCS passes this information to a computing device which then processes the information by model based optimization simulation programs, also referred to as the NO x Emissions Advisor. The presentation of recommendations to the operator consists of a series of graphic displays hierarchically arranged to present the operator with a simple summary that has available more detail support displays at lower levels. The NO x emissions automation system transmits the recommended positions to the controlling devices including furnace air dampers and coal feeders.
Inventors
- 👤 Donald E. Labbe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:38
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/003; F23N2223/00; F23N2223/40; F23N2223/44; F23N2225/00; F23N2225/04; F23N2225/08
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
105 words
A process for controlling NO x emissions of a system which comprises a plurality of levels, said process comprising the steps of: (a) obtaining the current status of controllable combustion parameters and the level of emissions produced from strategically located sensors; (b) analyzing the data to determine whether the level of NO x emissions can be reduced; (c) calculating the effect of changing various controllable combustion parameters; (d) determining if the effect by which NO x emissions can be reduced is cost effective; and (e) developing models which calculate the effect that changing various controllable combustion parameters has on the level of NO x emissions.
Claim 2
Dependent Claim
105 words
A process for controlling NO x emissions of a system which comprises a plurality of levels, said process comprising the steps of: (a) obtaining the current status of controllable combustion parameters and the level of emissions produced from strategically located sensors; (b) analyzing the data to determine whether the level of NO x emissions can be reduced; (c) calculating the effect of changing various controllable combustion parameters; (d) determining if the effect by which NO x emissions can be reduced is cost effective; and (e) developing models which calculate the effect that changing various controllable combustion parameters has on the level of NO x emissions.
Claim 3
Dependent Claim
15 words
A process as in claim 1 comprising the step of modifying the controllable combustion parameters.
Claim 4
Dependent Claim
21 words
A process as in claim 2 wherein the step of modifying the controllable combustion parameters is performed automatically through a computer.
Claim 5
Dependent Claim
25 words
A process as in claim 1 comprising the further step of displaying the effect of predicted changes compared to other changes in a graphic display.
Claim 6
Dependent Claim
28 words
A process as in claim 1 wherein the status of controllable combustion parameters and the level of emissions obtained in step (a) is entered into a custom logger.
Claim 7
Dependent Claim
55 words
A process as in claim 1 wherein the calculating of the effect of changing various controllable combustion parameters is performed by predicting the change that will occur in the system by implementing each one of many means for effecting a change serially and comparing the predicted change against current status level of NO x emissions.
Claim 8
Dependent Claim
29 words
A process as in claim 6 wherein the step of predicting each change that will occur in the level of NO x emissions is performed in a computer program.
Claim 9
Dependent Claim
29 words
A process as in claim 1 wherein the controllable combustion parameters obtained from strategically located sensors is comprised of temperature, pressure, flow, valve and damper position and generator output.
Claim 10
Dependent Claim
29 words
A process as in claim 1 wherein the emission levels obtained from strategically located sensors is comprised of NO x , CO 2 , CO, unburned carbon and fuel.
Claim 11
Dependent Claim
26 words
A process as in claim 1 wherein the system is provided with numerous fuel air dampers and auxiliary air dampers at each level in the system.
Claim 12
Independent Claim
119 words
An apparatus for determining the level by which NO x emissions can be reduced in a system, said apparatus comprising: (a) an assembly of sensors for obtaining the current status of controllable combustion parameters and the level of emissions; (b) a plurality of means for changing the controllable combustion parameters in the system; (c) a computer; (d) a computer program within the computer for analyzing the status of controllable combustion parameters and the level of NO x emissions and calculating changes to the controllable combustion parameters which reduce the level of NO x emissions; and (e) means for delivering the status of the controllable combustion parameters and the level of NO x emissions from the sensors to the computer.
Claim 13
Independent Claim
119 words
An apparatus for determining the level by which NO x emissions can be reduced in a system, said apparatus comprising: (a) an assembly of sensors for obtaining the current status of controllable combustion parameters and the level of emissions; (b) a plurality of means for changing the controllable combustion parameters in the system; (c) a computer; (d) a computer program within the computer for analyzing the status of controllable combustion parameters and the level of NO x emissions and calculating changes to the controllable combustion parameters which reduce the level of NO x emissions; and (e) means for delivering the status of the controllable combustion parameters and the level of NO x emissions from the sensors to the computer.
Claim 14
Dependent Claim
116 words
A process for regulating in a system comprising a plurality of burner levels the air damper positions comprising the steps of: (a) accessing the stoichiometric ratio at each burner level by measuring the fuel and air introduced at each level and comparing the ratio of the measured air to an amount of air theoretically required to completely combust the measured fuel; (b) accessing the feeder speed bias; (c) accessing the excess air control setpoint; (d) accessing the desired stoichiometric ratio; (e) accessing the desired furnace/windbox differential pressure; and (f) ascertaining from the data obtained in steps (a) through (e) the air damper positions which yields the desired stoichiometric ratio while maintaining the desired furnace/windbox differential pressure.
Claim 15
Dependent Claim
116 words
A process for regulating in a system comprising a plurality of burner levels the air damper positions comprising the steps of: (a) accessing the stoichiometric ratio at each burner level by measuring the fuel and air introduced at each level and comparing the ratio of the measured air to an amount of air theoretically required to completely combust the measured fuel; (b) accessing the feeder speed bias; (c) accessing the excess air control setpoint; (d) accessing the desired stoichiometric ratio; (e) accessing the desired furnace/windbox differential pressure; and (f) ascertaining from the data obtained in steps (a) through (e) the air damper positions which yields the desired stoichiometric ratio while maintaining the desired furnace/windbox differential pressure.
Claim 16
Dependent Claim
60 words
An apparatus as in claim 11 wherein the computer program is further configured to calculate the effect of changing various controllable combustion parameters, to determine if the effect by which NO x emission can be reduced is cost effective, and to develop models which calculate the effect that changing various controllable parameters has on the level of NO x emissions.
Claim 17
Dependent Claim
30 words
An apparatus as in claim 11 wherein the controllable combustion parameters obtained from the assembly of sensors is comprised of temperature, pressure, flow, valve and damper position and generator output.
Claim 18
Dependent Claim
29 words
An apparatus as in claim 11 wherein the emission levels obtained from assembly of sensors is comprised of NO x , CO 2 , CO, unburned carbon and fuel.
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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) | 1997-01-24 | 1997-07-26 | 1998-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-24 | 2001-07-26 | 2002-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-24 | 2005-07-26 | 2006-01-25 | $7700.00 | Window Closed / Lapsed |