US6595003B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for control of NOx in catalytic combustion systems
Assignee: Kawasaki Motors Ltd
•
Filing: 2001-08-31
•
Granted: 2003-07-22
•
Expires: 2021-08-31
Abstract
Abstract Methods and apparatus for control of NOx in catalytic combustion systems, and more particularly to control of thermal or/and prompt NOx produced during combustion of liquid or gaseous fuels in the combustor sections of catalytic combustor-type gas turbines, by controlled injection of water in liquid or vapor form at selected locations, orientations, amounts, rates, temperatures, phases, forms and manners in the compressor and combustor sections of gas turbines. The ratio of thermal NOx ppm reduction to water addition, in weight %, is on the order of 4-20, with % NOx reduction on the order of up to about 50-80% and NOx of below 2 ppm. Liquid water, steam or superheated steam can be used to reduce NOx in combustion systems operating at reaction zone temperatures above 900° C., preferably 1400° C. to 1700° C. The amount of water added is sufficient to provide a concentration of water in the range of from about 0.1% to about 20% by weight of the total air and fuel mixture flowing into the post catalyst reaction zone. Water is introduced simultaneously or sequentially in a plurality of locations, at selected rates, amounts, temperatures, forms, and purity, preferably in accord with a suitable control algorithm.
Inventors
- 👤 Ralph A. Dalla Betta
- 👤 Sarento G. Nickolas
- 👤 Timothy J. Caron
- 👤 Jon G. McCarty
- 👤 Mark J. Spencer
- 👤 II Robert A. Corr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:07
CPC Classifications
F; F23; F23C; F23C13/00; F01; F01K; F01K21/00; F01K21/04; F01K21/047; F23D; F23D14/00; F23D14/46; F23D14/68; F23L; F23L7/00; F23L7/002; F23R; F23R3/00; F23R3/40; F23L2900/00; F23L2900/07008; F23L2900/07009
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
126 words
In a method of operating a catalytic combustion system wherein fuel is introduced into and are mixed with process air flowing through a combustor or/and compressor, upstream of a catalyst module in said combustor to form a fuel/air mixture, a portion of the fuel in said fuel/air mixture is combusted in said catalyst module, and a portion of the fuel is combusted in a post catalyst reaction zone downstream of said catalyst module to provide a hot gases stream of a preselected output temperature value, the improvement comprising the step of introducing water from an external source into at least one of said process air, said fuel and said fuel/air mixture in an amount sufficient to reduce NO x produced in said post catalyst reaction zone.
Claim 2
Dependent Claim
126 words
In a method of operating a catalytic combustion system wherein fuel is introduced into and are mixed with process air flowing through a combustor or/and compressor, upstream of a catalyst module in said combustor to form a fuel/air mixture, a portion of the fuel in said fuel/air mixture is combusted in said catalyst module, and a portion of the fuel is combusted in a post catalyst reaction zone downstream of said catalyst module to provide a hot gases stream of a preselected output temperature value, the improvement comprising the step of introducing water from an external source into at least one of said process air, said fuel and said fuel/air mixture in an amount sufficient to reduce NO x produced in said post catalyst reaction zone.
Claim 3
Dependent Claim
21 words
Method as in claim 1 wherein said water is introduced in a phase selected from liquid water, steam, and mixtures thereof.
Claim 4
Dependent Claim
35 words
Method as in claim 2 wherein the fuel concentration in said fuel/air mixture is adjusted to compensate for the added mass of water and to maintain the gases output temperature at substantially a preselected value.
Claim 5
Dependent Claim
34 words
Method as in claim 3 wherein the water added provides a concentration of water in the range of from about 0.1% to about 20% by weight of the total mass of air and fuel.
Claim 6
Dependent Claim
32 words
Method as in claim 4 wherein the amount of water added is in the range of from about 1% to about 5% by weight of the total mass of air and fuel.
Claim 7
Dependent Claim
30 words
Method as in claim 2 wherein said introduced water is added simultaneously or sequentially in a plurality of locations along the path of the gases flow through said combustion system.
Claim 8
Dependent Claim
86 words
Method as in claim 6 wherein said water introduction locations include at least one of: adjacent the gases inlet to the catalyst module; in the catalyst module; at the exit of the catalyst module; upstream of a homogeneous combustion zone in said post catalyst reaction zone; in said post catalyst reaction zone; adjacent the introduction of catalyst fuel; intermixed in said fuel; and in association with additional fuel introduced downstream of said catalyst module and upstream of a homogeneous combustion zone, and combination of said locations.
Claim 9
Dependent Claim
109 words
Method as in claim 2 in which said catalytic combustion system is disposed in a combustion section of a gas turbine, said combustor section includes a pre-burner section upstream of said catalytic combustion system, a compressor section is disposed upstream of said combustor section, and the output hot gas stream feeds said turbine, wherein said water is introduced selectively in at least one location along the path of gases flow into and through said compressor section and said combustor section, and when water is introduced in a plurality of locations said introduction may be simultaneous or sequential in accord with operating conditions, including selected level of NO x reduction.
Claim 10
Dependent Claim
31 words
Method as in claim 8 wherein water is introduced in at least one mode selected from mixed in said fuel, separately from said fuel or combinations of said modes of introduction.
Claim 11
Dependent Claim
24 words
Method as in claim 8 wherein water is introduced in said preburner section in amounts sufficient to reduce NO x produced in said preburner.
Claim 12
Dependent Claim
26 words
Method as in claim 8 wherein water is introduced upstream in said preburner section in amounts sufficient to reduce NO x produced in said preburner section.
Claim 13
Dependent Claim
27 words
Method as in claim 11 wherein water is introduced upstream in at least one location selected from said compressor inlet, interstage in said compressor, and combinations thereof.
Claim 14
Dependent Claim
55 words
Method as in claim 1 which includes the steps of measuring NO x level in at least one of the combustor section gases, combustor section outlet gases, and where the combustor section feeds a turbine, the turbine outlet gases; and controlling the introduction of water to limit the NO x to a preselected value range.
Claim 15
Dependent Claim
29 words
Method as in claim 13 wherein said control step includes a feedback loop comprising substantially continuous measurement of the NO x level and adjustment of water introduction responsive thereto.
Claim 16
Dependent Claim
50 words
Method as in claim 1 in which includes the steps of determining the adiabatic combustion temperature adjacent the outlet of said combustor section; and introducing said water in accord with a schedule of water injection rate to adiabatic combustion temperature needed to reduce NO x to a preselected target level.
Claim 17
Dependent Claim
29 words
Method as in claim 15 wherein said schedule is derived from consideration of NO x produced vs temperature in said combustor section and NO x reduction vs water injection.
Claim 18
Dependent Claim
36 words
Method as in claim 16 wherein said NO x value produced at said combustor section temperature is an estimated value of NO x produced in both said post catalyst reaction zone and in said preburner section.
Claim 19
Dependent Claim
38 words
Method as in claim 17 wherein NO x produced in said preburner is controlled by introduction of water in at least one location of: upstream of said preburner section; in said preburner section; and combinations of said locations.
Claim 20
Dependent Claim
39 words
Method as in claim 18 which includes the steps of recovering waste heat from said combustion to convert water to high pressure steam for introduction in at least one of said compressor, said preburner section, and said combustor section.
Claim 21
Dependent Claim
125 words
Apparatus for reduction of NO x produced in a combustor section of a gas turbine downstream of a compressor section, which combustor section includes a catalytic combustion system, comprising: a) at least one water source; b) at least one manifold connecting said water source to at least one of said combustion section and said compressor section for introduction of water into the process gasses flowing into and through said compressor section and into and through said combustor section, at selected one or more locations along the flow path of said gases; and c) at least one controller that controls the introduction of water in amounts sufficient to reduce NO x otherwise produced in said combustor section in accord with a target NO x value range.
Claim 22
Dependent Claim
125 words
Apparatus for reduction of NO x produced in a combustor section of a gas turbine downstream of a compressor section, which combustor section includes a catalytic combustion system, comprising: a) at least one water source; b) at least one manifold connecting said water source to at least one of said combustion section and said compressor section for introduction of water into the process gasses flowing into and through said compressor section and into and through said combustor section, at selected one or more locations along the flow path of said gases; and c) at least one controller that controls the introduction of water in amounts sufficient to reduce NO x otherwise produced in said combustor section in accord with a target NO x value range.
References Cited (Backward Citations)
US4283634A
Cited
US4380146A
Cited
US4930454A
Cited
US4687491A
Cited
US5095221A
Cited
US5232357A
Cited
US5183401A
Cited
US5250489A
Cited
US5281128A
Cited
US5425632A
Cited
US5826422A
Cited
US5987878A
Cited
US5729967A
Cited
US6294842B1
Cited
US6095793A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-07-21 | 2007-01-20 | 2007-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-07-21 | 2011-01-20 | 2011-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-07-21 | 2015-01-20 | 2015-07-22 | $7700.00 | Window Closed / Lapsed |