CA1107517A - Catalysis - Google Patents
CatalysisInfo
- Publication number
- CA1107517A CA1107517A CA298,126A CA298126A CA1107517A CA 1107517 A CA1107517 A CA 1107517A CA 298126 A CA298126 A CA 298126A CA 1107517 A CA1107517 A CA 1107517A
- Authority
- CA
- Canada
- Prior art keywords
- group
- metallic monolith
- gas turbine
- layer
- turbine engine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23R—GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
- F23R3/00—Continuous combustion chambers using liquid or gaseous fuel
- F23R3/40—Continuous combustion chambers using liquid or gaseous fuel characterised by the use of catalytic means
Abstract
ABSTRACT OF THE DISCLOSURE
A novel gas turbine engine is provided herein having as an essen-tial component thereof, a catalytic combustor. The catalytic combustor comprises: (a) a pilot burner adapted to consume not more than 5% of the total fuel consumption of the engine at full power; (b) a combining cham-ber for combining and mixing effluent hot gases from the pilot burner with additional hot compressed air at a pressure within the range 1 - 20 atmos-pheres delivered from a compressor turbine, the chamber having an inlet to receive the effluent hot gases and the hot compressed air, and an exit to discharge therefrom the combined hot gases; (c) an injector capable, under full power conditions, of injecting a major portion of the total fuel re-quirement directly into the combined hot gases leaving the chamber; and (d) a thermally stable and oxidation-resistant metallic monolith containing a multiplicity of flow paths or channels whose surfaces possess catalytic activity such that catalytic combustion of combustible gases and injected fuel may take place, the walls of the metallic monolith possessing a thickness within the range 0.002 to 0.004 inch. By this invention, cataly-tic oxidation of a major proportion of the fuel takes place and produces a considerable reduction in the quantity of pollutant present in the ex-haust gases.
A novel gas turbine engine is provided herein having as an essen-tial component thereof, a catalytic combustor. The catalytic combustor comprises: (a) a pilot burner adapted to consume not more than 5% of the total fuel consumption of the engine at full power; (b) a combining cham-ber for combining and mixing effluent hot gases from the pilot burner with additional hot compressed air at a pressure within the range 1 - 20 atmos-pheres delivered from a compressor turbine, the chamber having an inlet to receive the effluent hot gases and the hot compressed air, and an exit to discharge therefrom the combined hot gases; (c) an injector capable, under full power conditions, of injecting a major portion of the total fuel re-quirement directly into the combined hot gases leaving the chamber; and (d) a thermally stable and oxidation-resistant metallic monolith containing a multiplicity of flow paths or channels whose surfaces possess catalytic activity such that catalytic combustion of combustible gases and injected fuel may take place, the walls of the metallic monolith possessing a thickness within the range 0.002 to 0.004 inch. By this invention, cataly-tic oxidation of a major proportion of the fuel takes place and produces a considerable reduction in the quantity of pollutant present in the ex-haust gases.
Description
11C~7517 Thls invention relates to gi-s turbine engincs ln wh~ch catalytic oxidation of a major proportion of the fuel takes place and produces a con-siderable red~lction in the quant~ty of pollutant present in the exhaust gases.
At present it is unusual for a gas turbine to utilize catalytic combustion for even a proportion of the inlet fuel. The main difficulty confronting designers of gas turbines utilizing catalytic combustion is the very high throughputs of air or oxygen and fuel involved. The volume of catalyst required to ensure effective surface reaction of a major propor-tion of the combusting gases is totally unrealistic in relation to the de-signs for turbines currently in use.
An object of a broad aspect of the present invention is to provide gas turbine in which a major proportion of the fuel undergoes catalytic combustion within th~ confines of a combustion chamber having a volume of similar order to that of turbines presently operating.
According to one aspect of the invention a gas turbine engine is provided including a catalytic combustor, the catalytic combustor compris-ing (a) a pilot burner adapted to consume not more than 5~ of the total fuel consumption of the engine at full power; (b) a combining chamber for combining and mixing effluent hot gases from the pilot burner with addition-al hot compressed air at a pressure wi~hin the range 1 - 20 atmospheres - . ,, delivered from a compressor turbine, the chamber having an inlet to receive the effluent hot gases and the hot compressed air, and an exit to dis-charge therefrom the combined hot gases; (c) an injector capable, under full power conditions, of injecting a ma~Or portion of the total fuel require-ment directly into the combined hot Rases leaving the chamber; and (d) a thermally stable and oxidation-resistant metallic monolith containing a multiplicity of flow paths or channels whose surfaces possess catalytic activity such that catalytic combustion of combustible gases and injected
At present it is unusual for a gas turbine to utilize catalytic combustion for even a proportion of the inlet fuel. The main difficulty confronting designers of gas turbines utilizing catalytic combustion is the very high throughputs of air or oxygen and fuel involved. The volume of catalyst required to ensure effective surface reaction of a major propor-tion of the combusting gases is totally unrealistic in relation to the de-signs for turbines currently in use.
An object of a broad aspect of the present invention is to provide gas turbine in which a major proportion of the fuel undergoes catalytic combustion within th~ confines of a combustion chamber having a volume of similar order to that of turbines presently operating.
According to one aspect of the invention a gas turbine engine is provided including a catalytic combustor, the catalytic combustor compris-ing (a) a pilot burner adapted to consume not more than 5~ of the total fuel consumption of the engine at full power; (b) a combining chamber for combining and mixing effluent hot gases from the pilot burner with addition-al hot compressed air at a pressure wi~hin the range 1 - 20 atmospheres - . ,, delivered from a compressor turbine, the chamber having an inlet to receive the effluent hot gases and the hot compressed air, and an exit to dis-charge therefrom the combined hot gases; (c) an injector capable, under full power conditions, of injecting a ma~Or portion of the total fuel require-ment directly into the combined hot Rases leaving the chamber; and (d) a thermally stable and oxidation-resistant metallic monolith containing a multiplicity of flow paths or channels whose surfaces possess catalytic activity such that catalytic combustion of combustible gases and injected
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fllel may take place, the walls of the metallic monolith possessing a thick-ness withln the range 0.002 to 0.004 inch.
According to another aspect of the invention, a gas turbine engine ~, is provided, comprising (a) a compressor turbine for producing a supply of hot compressed at a pressure within the range 1-20 atmospheres to a com-bustor section; (b) means for take-off and by-pass of a major proportion of the air flow the means being disposed subsequent to the compressed air in-let from the compressor turbine; (c) a pilot burner fuelled by a fuel in-jector and adapted to consume not more than approximately 5% of the total fuel consumption of the engine at full power; (d) a combining chamber for combining the hot gas effluent from the pilot burner (c) with a proportion of the hot compressed air removed at stage (b); (e) an injector capable under full power conditions, of injecting at least a major portion of the total fuel requirement directly into the effluent hot gases exiting from chamber (d); (f) a catalytic combustor section comprising a temperature stable and oxidation resistant metallic monolith, the metallic monolith having walls possessing a thickness within the range 0.002 - 0.004 inches and providing catalytic channels for contact with and passage therethrough of the combusting gases combined with injected fuel at stage (e) such that combustion of a substantial proportion of the uncombusted fuel takes place but in which a pressure drop not greater than 10% is produced; (g) a reac-tion chamber subsequent to the catalytic combustor section in which com-bustion continues, and (h) a gas generator turbine which may be engaged in a mechanically rigid manner to the compressor turbine and which is driven by expansion of the hot combusting gases produced by the engine.
In section (a) the temperature of air leaving the compressor tur-bine is preferably within the range 25C to 600C and at a pressure within the range 1 atm to 20 atm.
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~-~ In section (b) up to approximately 60% of the compressed air is taken off. The quantity of air taken off is preferably within the range 75~7 10~ to SOZ by volllme.
In section (c) the pilot burl)er burns not more than approximately 5~ by weight of the total fuel consump~ion of the engine at full power.
The proportion of fuel utilised by the pilot burner during normal running may range fro~ 0.1~ by weight to 50% or 66 2/3~ by weight. The fuel in-jection for the pilot burner is able to control the quantity of fuel and ad-justed primarily to give a temperature within a specific preferred range in the combining chamber. A typical preferred temperature range in the combining chamber is 200C to 500C. The pilot burner is normally adjusted for the combustion of a fuel-air mixture ranging approximately from stoichi-ometric to rich. It utilizes the remaining compressed air not taken off at stage ~b).
In a preferred embodiment, four separate fuel injectors are used in the pilot burner stage spaced from each other at angles of 90C in the vertical plane. Similarly a multi-injector array may be used in place of the single injector.
In the reaction chamber section which preferably contains a bluff body, this combustion commenced in contact with the metallic monolith continues and combustion also commences of virtually all of the remainder of the combusted fuel.
By a variant of all these aspects, the injector is positioned di-rectly in the path of the hot combined gases leaving the combining chamber.
Preferably the metallic monolith in section according to a variant of this invention is formed from one or more metals selected from the group comprising Ru, Th, Pd, Ir and Pt. However base metals may be used or base metal alloys which also contain a platinum group metal component may be used.
By a variation thereof, the metallic monolith-is-made--from 10%-rhodium/platinum alloy.
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-By enother variation thereof, the metallic monolith is made from a nickel/chro~ium alloy having an aggregate Ni plus Cr content greater than 20% by weight.
By another variation thereof, the metallic monolith is made from an alloy of iron including at least one of the elements chromium (3-40) wt.%, s]~minum (1-10) wt. %~ cobalt (trace-5) wt.% and carbon (trace-0.5) wt.%.
By another variation thereof, the metallic monolith is made from an alloy comprising 0.5-12 wt.% Al, 0.1-3.0 wt.% Y, 0-20 wt. % Cr and bal-.
ance Fe~
By another variation thereof, the metallic monolith is made from an alloy comprising 0.5-4 wt.% al, 0.5-3.0 wt. % Y, 20.0 - 95.0 wt.% Cr and balance Fe.
By aDother variation thereof, the metallic monolith is made from an alloy comprising at least 45 wt.% Ni or at least 40 wt.% Co, a trace to 30 wt.% Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru.
By another variation thereof, the metallic monolith is made from an alloy comprising at least 40 wt.% Ni or at least 40 wt.% Co, a trace to ,, ~
30 wt.% Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru and further containing from a trace to the percentage specified of at least one of the following elements: -by weight Co 25 Ti 6 Al 7 Mo 20 Hf ~ 2 , ~ ~ ~- Mn 2 ~,.....
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~7517 70 by we_&ht Si 1.5 V 2.0 Nb B 0.15 C 0.05 Ta 10 Zr 3 Fe 20 Th and rare earth metals 3 or oxides By another variation thereof, the metallic monolith is in the form of an interwoven wire gauze, mesh, or corrugated sheet, or foil.
By another variation thereof2 the metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys containing a platinum group metal and wherein the metal1ic monolith has a first layer of an oxygen con-taining material and a second catalytic layer.
By a further variation, the first layer is an oxide selected from the group consisting of alumina, silica, titania, zirconia, hafnia, thoria, beryllia, magnesia, calcium oxide, strontium oxide, barium oxide, chromia, boria, scandium oxide, yttrium oxide and oxides of the lanthanides.
By a further variation, the first layer is an oxygen-containing anion selected from the group consisting of chromate, phosphate, silicate and nitrate.
By another variation thereof, the second catalytic layer is a metal selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ag, an ~,~- alloy containing at least one of the metals and alloys containing at least one of the metals and a base metal.
~y another variation thereof, the second catalytic layer com-- - 6 ~
11~7S17 prises at least one intermetallic compounds of the general formula AXBy, where A is selected from the group consisting of Ru, Rh, Pd, Ir, and Pt, wherein B is selected from the group consisting of Al, Se, Y, the lanthan-ides, Ti, Zr, Hf, V, Nb, and Ta, and wherein x and y are integral and may have values of 1 or more.
The walls of the metal]ic monolith according to another variant of this invention preferably have a thickness within the range 2-4 thousandths of one inch. The preferred characteristics of the metallic monolith having catalyst deposited thereon are (i) that it presents low resistance to the passage of gases by virtue of its possession of a high ratio of open area to blocked area and (ii) that it has a high surface to volume ratio. -A typical 200 cells per square inch ceramic monolith usedin another variant of this invention has walls 0.008 - 0.011 inches thick, a 71% open area and a 15% pressure drop. A typical 400 cells per square inch metallic monolith used in aspects of ~he present invention has walls 0.002 inches thick, a 91 - 92% open area and a 4% pressure drop. A 200 cell per square inch metallic monolith still has a 95% open area and a pressure drop of 4% or less.
Suitable platinum-group metals for use in fabrication of the metallic monolith according to variants of this invention are platinum, 10%
rhodium-platinum and dispersion strengthened platinum group metals and alloys as described in British Patent Specification Nos. 1,280,815 and 1,340,076 and United States Patent Specifications Nos. 3,689,987, 3,696,502 and 3,709,667.
Suitable base metals which may be used are those capable of with-standing rigorous oxidising conditions. Examples of such base metal alloys according to yet other variants of this invention are nickel and chromium alloys having an aggregate Ni plus Cr content greater than 20% by weight and - 6 ~
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1~37517 alloys of iron including at least one of the elements chromium (3-40) wt.%, aluminum (1-10) wt.%, cobalt (trace-5) wt.%, nickel (trace-72) wt.% and carbon (trace-0.5) wt.%. Such substrates are described in copending Canadian application Serial No. 230,898.
Other examples of base metal alloys capable of withstanding the rigorous conditions required according to other variants of the invention are iron-aluminum-chromium alloys which may also contain yttrium. The latter alloys according to yet other variants may contain 0.5-12 wt.% Al, 0.1-3.0 wt.% Y, 0.20 wt.% Cr. and balance Fe. These are described in United States Patent No. 3,298,826. Another range of Fe-Cr-Al-Y alloys within other variants contain 0.5 - 4 wt.% Al, 0.5 - 3.0 wt.% Y, 20.0 -95.0 wt.% Cr and balance Fe and these are described in United States Patent No. 3,027,251.
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` ``` 1~7S~7 Base metal alloys which also contain a platinum group metal comr ponent according to yet other variants are useful as a catalycic metal-lic monolith in very fierce oxidising conditions, for example in catalysis of the combustion in gas turbine enginr-~s. Such alloys are described in German DOS 2530245 and contain at least 40 wt.% Ni or at least 40 wt.% Co, a trace to 30 wt.%
Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru. The alloys may also contain from a trace to the percentage specified of any one or more of the following elements:- -% by we i ght Co 25 Ti 6 Al 7 Mo 20 2 Hf 2 Mn 2 Si 1.5 V 2.0 _ 7 _ .. - ~ , .
11~)75~7 S6 by weight B 0.15 C 0.05 Ta 10 Zr 3 Fe 20 Th and rare earth metals 3 or oxides l~here the metallic substrate is composed either substantially or s~lely Or platinum group metal it may according to another variant be in the form of an interwoven wire gauze or mesh or corrugated sheet or foil.
Where the metallic substrate is composed substantially of base metal it is preferably in the form of corrugated sheet or foil. These types of base metal monoliths are also described in German DOS 2450664 and they may be used in turbines according to the present invention. Such base metal monoliths may have deposited thereon according to other variants thereof ;
a first layer comprising an oxygen containing coating and a second and catalytic layer. The oxygen containing coating is usually present as an oxide selected from the group consisting of alumina, silica, titania, zirconia, hafnia, thoria, beryllia, magnesia, calcium oxide, strontium oxide, barium oxide, chromia, boria, scandium oxide, yttrium oxide and oxides of the lanthanides. Alternatively, by another variant, the oxygen in the first layer is present as an oxygen containing anion selected from the group consisting of chromate, phosphate, silicate and nitrate. The second catalytic layer may, for example, comprise a metal s~lected from the group consisting of Ru, Rh, Pd, .~ .
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- ~ ' ~1~7517 Ir, ~'t, Au~ Ag, an alloy containing at least one of the ~etals and alloys containing at least one of the metals and a base metal. The first and second layers may be deposited or otherwise applied to the monolith as described in Canadian Patent No. 1,078,364 issued May 27, 1980.
Alternative catalytic monoliths for use in section (f) according to aspects of this invention are the following structures, namely, a catalyst comprising a metallic substrate having deposited thereon a surfaee coating consisting of one or more intermetallic compounds of the general formula A B where A is selected from the group consisting of Ru, Rh, Pd, lQ Ir, and Pt and B is selected from the group consisting of Al, Sc, Y, the lanthanides, Ri, Zr, Hf, V, Nb, and Ta and x and y are integral and may have values of 1 or more. The surface coating of intermetallic compoundsis, preferably, in the form of a thin film ranging in thickness from 2 to 15 microns.
Many compounds of the type A B are miscible with one another and structures in which the surface coatings deposited upon the metallic sub-strate contains more than one compound of the type A B are within the scope of this invention.
When the intermetallic compound is deposited in the form of a coating not more than 15 microns thick upon the surface of a metallic sub-strate, excessive brittleness is absent and the coa,ed substrate may be handled normally.
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~1~75~7 A number of diffcrent techniques may be employed to produce a coating in the form of a thin film of intermetallic compound upon the surface of the metal metallic monolith. For examF?le, aluminum may be depositcd onto the surface of rhodium-platinum gauzes by a pack-slumirising process. In this process the gauzes are packed into a heat-resistant container in an appropriate mixture of chemicals such that alumirn,m is transferred via the v~pour phase to the g~uze surface.
At the aluminising temperature, typically 800-900 C, interaction between ths platinum and aluminum occurs to give the required intermetallic compound Alternatively, chemical vapour deposition from ZrG14 can be used to form a layer of Pt3Zr, or electrodeposition may be used either from aqueous or fused salt electrolysis to give the requisite compound.
Whichever process is adopted the objective is to form a layer of a firmly adherent, intermetallic compound on the wires of the gauze pack or other substrate.
In another technique, the metals forming the intermetallic compound are prepared as an aporopriate solution in water or an organic solvent. The compound is caused to deposit upon the metallic substrate or gauze by the addition of a reducing agent.
The m etal I ic substrate is placed in the solution whilst the precipitation is taking place and becomes coatea with a uniform, microcrystalline layer of the interm etal I ic compound .
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i'r~U'c~ LIIC r~ct i~ cl~ nl)~l (g) cu~ .lins .I L l.uff bo(ly wllk:ll ., ~ t~ f~ t ~,r ~ L~ r~.lctioll initi~lL~ tll~ _ caL,l.lyLic con~l)ustol~ ~eCL.ioll (I ).
Suit.lble blurL l)odios accorclillg to variants of tllis invention are fal)ricated ~rom ~lle same matcrials as the temperature stable and oxidation resistallt metallic monolitll of section (f). The compositions of such alloys are detcliled in full above and examples of alloys we have found to be useful are those known by the Trade marks of Inconel 600 and 601. The Nimonic alloys, Incoloy 800 and the Nichrome alloys (Registered 10 Trade Marks), stainless steels and platinum group metals may also be used. r In the accompanying drawings, Figure 1 is a diagrammatic cross section of a preferred embodiment including an optional variable vane fluid (air) control system;
- and Figure 2 shows a different engine grometry showing a fluid flow control system in which variable vanes are not used is shown.
r - In Figure 1 a compressor turbine (which is not shown) produces hot compressot feed air indicated by and moving in the direction indicated by arrow F.
Section (b) of the turbine as defined above may include a variable vane system for controliing the flow of F (preburner air) F2 (preburner di!ution air) and F3 (by-pass air). From Figure 1 it will be seen that . ~ ,.................................................................... ~
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~llfJ7S:17 the flow F1 is dirccted lo a preburner injector lland the igni tor L, whercas the flows F2 and F3 by-passIt and L 1. During start up flows F2 and F3 are quite low and nearly all of the incoming hot compressor feed air F passes the preburnerI 1 and injector L1 On ignition the flow F2 and/or the fuel injectorl can be adjusted to produce temperatures of the flow F4 (i.e. F1+ F2) suitable for main burner ignition by igniting I2 and, consequently, optimum performaace. When these cor,ditions are achieved, the main burner in section (e) may be started and the flow F2 will be unrestricted. In these conditions, a flow F6 (which is controlled by operation of variable vanes V2) is also permitted and the quantity of fuel injected by main injector ~-2 is adjusted such.that diluted power turbine feed F8 is at the desired gas temperature for optimum performance. The start up will normally reach ignition prior to the end of "engine-cranking", but self-sustaining speed may not yet be achieved -and "engine-cranking" may be continued to that speed. The flow F3 provides wall cooling and blade cooling contact air if required.
Heated gas from diluted preburner (pilot burner) exhaust is mixed with air in chamber (d) as defined above and fed at sufficient temperature to the main catalytic combustor (f) where it mixes with fuel from injector I2 (e) and passes over the catalyst monolith C. The catalyst C
burns some or all of the fuel and any remainder is burnt by free radical reaction immediately downstream of the catalyst. Further dilution is - .
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available by introduction of air from the flow F3 if necessary. Further, a large flow F6 ignited by an emergency igniter I3 provides emergency power as required.
Throttle response is achieved by control of fuel injection and by sequenced operation of igniters Il and I2.
A variable vane system is not essential and in Figure 2 (where the same reference symbols are used) an alternative geometry is depicted in which division of the air flow is accomplished by geometric fluidic control.
T is a temperature probe which is connected via a feedback circuit to con-trol injector Il, in Figures 1 and 2 an optional bluff body is indicatedby reference B.
In a preferred embodiment, four separate fuel injections are used in the pilot burner stage (c) spaced from each other at angles of 90C
`` in the vertical plane shown at position Il in Figure 2. Similarly a multi-injection array may be used in place of the single injection shown at I2 in Figure 2.
EXAMPLE
~- The turbine used as a Rover/Lucas 60 b.h.p. simple cycle turbine on a Heenan and Froude G type dynamometer. The analytical equipment used was the following:
Gas Detector Method CO, C02 Non-dispersive infra red (Analytical Development Ltd.) HC Flame ionisation detector (IP~I) NO Luminox 201 (BOC) Oz Servomex.
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75~7 Cllromel-A]tlmel thermocouples llnked to an MBM high speed data logger and punch unit were used for tcmperature measurement. Fuel consump-tion was determined by gravimetric systems and air consumption by venturi depression metering. Commercially available diesel fuel (DERV) was used.
The engine was run itially with the production flame combustor to determine the normal parameters. The results aré given in Table 1.
The exhaust gas analyses obtained for these runs are given in Table 2. On the basis of the idle and emergency power settings, the emission index for each gas was calculated and these figures are given in Table 3.
The standard combustor was then replaced by the catalytic system described above and shown in diagrammatic form in Figure 2. An idle test was performed under the same conditions as for the flame combustor. The exhaust analysis for the catalytic combustor is given in Table 4, together with the emission index figures.
During this catalyst test it was observed that the fuel injection system was delivering a mixture to the catalyst which was toorich. De-spite this, however, the emission index is considerably below that recorded for the flame combustion engine.
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1~7517 The catalyst used as a 400 cell per square inch Fecralloy (Regi6-tered Trade Mark) metallic monolith substrate having a wall thickne6s of 0.002 lnches. Washcoat used was 5 parts Kaiser "SAM" alumina to 1 part barium stabilized "Sol-Gel" alumina (UKAEA) at a loading of lg per cubic inch of monolith. Platinum was deposited on the washcoàt by known techniques at a loading of 150g per cubic foot of washcoated monolith.
A Kanthal D (Registered Trade Mark) metallic monolith substrate also having a wall thickness of 0.002 inches may replace the Fecralloy substrate in this test.
`75~7 Tsble 1.
Dat _ r m~ turbine runninR with production flame combustor Test Condition * 1 2 3 4 5 Brake load (relative) 10 40 70 95.2 10 Time to consume 21. fuel (sec)230 201167 145 230 Impellor tip press.(p.s.i.g.) 3.4 3.63.7 3.8 3.5 Compressor delivery press. (p.s.i.g.) 26 26.627.9 28.1 26 Compressor delivery press. (p.s.i.a.) 41 41.642.9 43.1 41 Combustor back press. (cm.Hg)15.5 15.714.4 14.015.7 Exhaust press. (cm.H20) 5.3 3.22.0 -2.3 4.3 Air venturi depression (cm.H20)24.6 22.422.0 20.524.5 Air temp. ((F) 68 68 68 68 68 Jet Pipe temp (C) 385 453535 594 378 * 1 = sustaining idle; 2 = mid-power, 3 = baseline power, 4 = emergency power; 5 = idle - Table 2.
Exhaust Analysis Test No. 1 2 3 4 5 HC ppm 350 180150 140 360 N0 ppm 13 22 33 44 17 N0 ppm 22 24 42 58 18 CO ppm 1450 - 150 97 1121560 2% ~ 2.5 3 3.7 4.5 2.4 ; 2 % 18 17.5 16.7 15.7 18.
., ~1~75~7 Table 3.
F~iseio= 1ndices in g/k~ Fuel Test No. 1 4 HC 53.4 12.26 N0 1.5 2.82 N0 2.3 3,72 C0 150.0 6.24 Table 4.
Exhaust analysis and emission index figures for catalYtic combustor 10 Exhaust Analysis Emission Index (g/kg. fuel) HC 30 ppm 4.5 N0 1 0.11 N0x 1 0.11 C0 150 15.5 .
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fllel may take place, the walls of the metallic monolith possessing a thick-ness withln the range 0.002 to 0.004 inch.
According to another aspect of the invention, a gas turbine engine ~, is provided, comprising (a) a compressor turbine for producing a supply of hot compressed at a pressure within the range 1-20 atmospheres to a com-bustor section; (b) means for take-off and by-pass of a major proportion of the air flow the means being disposed subsequent to the compressed air in-let from the compressor turbine; (c) a pilot burner fuelled by a fuel in-jector and adapted to consume not more than approximately 5% of the total fuel consumption of the engine at full power; (d) a combining chamber for combining the hot gas effluent from the pilot burner (c) with a proportion of the hot compressed air removed at stage (b); (e) an injector capable under full power conditions, of injecting at least a major portion of the total fuel requirement directly into the effluent hot gases exiting from chamber (d); (f) a catalytic combustor section comprising a temperature stable and oxidation resistant metallic monolith, the metallic monolith having walls possessing a thickness within the range 0.002 - 0.004 inches and providing catalytic channels for contact with and passage therethrough of the combusting gases combined with injected fuel at stage (e) such that combustion of a substantial proportion of the uncombusted fuel takes place but in which a pressure drop not greater than 10% is produced; (g) a reac-tion chamber subsequent to the catalytic combustor section in which com-bustion continues, and (h) a gas generator turbine which may be engaged in a mechanically rigid manner to the compressor turbine and which is driven by expansion of the hot combusting gases produced by the engine.
In section (a) the temperature of air leaving the compressor tur-bine is preferably within the range 25C to 600C and at a pressure within the range 1 atm to 20 atm.
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~-~ In section (b) up to approximately 60% of the compressed air is taken off. The quantity of air taken off is preferably within the range 75~7 10~ to SOZ by volllme.
In section (c) the pilot burl)er burns not more than approximately 5~ by weight of the total fuel consump~ion of the engine at full power.
The proportion of fuel utilised by the pilot burner during normal running may range fro~ 0.1~ by weight to 50% or 66 2/3~ by weight. The fuel in-jection for the pilot burner is able to control the quantity of fuel and ad-justed primarily to give a temperature within a specific preferred range in the combining chamber. A typical preferred temperature range in the combining chamber is 200C to 500C. The pilot burner is normally adjusted for the combustion of a fuel-air mixture ranging approximately from stoichi-ometric to rich. It utilizes the remaining compressed air not taken off at stage ~b).
In a preferred embodiment, four separate fuel injectors are used in the pilot burner stage spaced from each other at angles of 90C in the vertical plane. Similarly a multi-injector array may be used in place of the single injector.
In the reaction chamber section which preferably contains a bluff body, this combustion commenced in contact with the metallic monolith continues and combustion also commences of virtually all of the remainder of the combusted fuel.
By a variant of all these aspects, the injector is positioned di-rectly in the path of the hot combined gases leaving the combining chamber.
Preferably the metallic monolith in section according to a variant of this invention is formed from one or more metals selected from the group comprising Ru, Th, Pd, Ir and Pt. However base metals may be used or base metal alloys which also contain a platinum group metal component may be used.
By a variation thereof, the metallic monolith-is-made--from 10%-rhodium/platinum alloy.
, .
' '.
- : . - - .
-By enother variation thereof, the metallic monolith is made from a nickel/chro~ium alloy having an aggregate Ni plus Cr content greater than 20% by weight.
By another variation thereof, the metallic monolith is made from an alloy of iron including at least one of the elements chromium (3-40) wt.%, s]~minum (1-10) wt. %~ cobalt (trace-5) wt.% and carbon (trace-0.5) wt.%.
By another variation thereof, the metallic monolith is made from an alloy comprising 0.5-12 wt.% Al, 0.1-3.0 wt.% Y, 0-20 wt. % Cr and bal-.
ance Fe~
By another variation thereof, the metallic monolith is made from an alloy comprising 0.5-4 wt.% al, 0.5-3.0 wt. % Y, 20.0 - 95.0 wt.% Cr and balance Fe.
By aDother variation thereof, the metallic monolith is made from an alloy comprising at least 45 wt.% Ni or at least 40 wt.% Co, a trace to 30 wt.% Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru.
By another variation thereof, the metallic monolith is made from an alloy comprising at least 40 wt.% Ni or at least 40 wt.% Co, a trace to ,, ~
30 wt.% Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru and further containing from a trace to the percentage specified of at least one of the following elements: -by weight Co 25 Ti 6 Al 7 Mo 20 Hf ~ 2 , ~ ~ ~- Mn 2 ~,.....
. , :
~7517 70 by we_&ht Si 1.5 V 2.0 Nb B 0.15 C 0.05 Ta 10 Zr 3 Fe 20 Th and rare earth metals 3 or oxides By another variation thereof, the metallic monolith is in the form of an interwoven wire gauze, mesh, or corrugated sheet, or foil.
By another variation thereof2 the metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys containing a platinum group metal and wherein the metal1ic monolith has a first layer of an oxygen con-taining material and a second catalytic layer.
By a further variation, the first layer is an oxide selected from the group consisting of alumina, silica, titania, zirconia, hafnia, thoria, beryllia, magnesia, calcium oxide, strontium oxide, barium oxide, chromia, boria, scandium oxide, yttrium oxide and oxides of the lanthanides.
By a further variation, the first layer is an oxygen-containing anion selected from the group consisting of chromate, phosphate, silicate and nitrate.
By another variation thereof, the second catalytic layer is a metal selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ag, an ~,~- alloy containing at least one of the metals and alloys containing at least one of the metals and a base metal.
~y another variation thereof, the second catalytic layer com-- - 6 ~
11~7S17 prises at least one intermetallic compounds of the general formula AXBy, where A is selected from the group consisting of Ru, Rh, Pd, Ir, and Pt, wherein B is selected from the group consisting of Al, Se, Y, the lanthan-ides, Ti, Zr, Hf, V, Nb, and Ta, and wherein x and y are integral and may have values of 1 or more.
The walls of the metal]ic monolith according to another variant of this invention preferably have a thickness within the range 2-4 thousandths of one inch. The preferred characteristics of the metallic monolith having catalyst deposited thereon are (i) that it presents low resistance to the passage of gases by virtue of its possession of a high ratio of open area to blocked area and (ii) that it has a high surface to volume ratio. -A typical 200 cells per square inch ceramic monolith usedin another variant of this invention has walls 0.008 - 0.011 inches thick, a 71% open area and a 15% pressure drop. A typical 400 cells per square inch metallic monolith used in aspects of ~he present invention has walls 0.002 inches thick, a 91 - 92% open area and a 4% pressure drop. A 200 cell per square inch metallic monolith still has a 95% open area and a pressure drop of 4% or less.
Suitable platinum-group metals for use in fabrication of the metallic monolith according to variants of this invention are platinum, 10%
rhodium-platinum and dispersion strengthened platinum group metals and alloys as described in British Patent Specification Nos. 1,280,815 and 1,340,076 and United States Patent Specifications Nos. 3,689,987, 3,696,502 and 3,709,667.
Suitable base metals which may be used are those capable of with-standing rigorous oxidising conditions. Examples of such base metal alloys according to yet other variants of this invention are nickel and chromium alloys having an aggregate Ni plus Cr content greater than 20% by weight and - 6 ~
.~
1~37517 alloys of iron including at least one of the elements chromium (3-40) wt.%, aluminum (1-10) wt.%, cobalt (trace-5) wt.%, nickel (trace-72) wt.% and carbon (trace-0.5) wt.%. Such substrates are described in copending Canadian application Serial No. 230,898.
Other examples of base metal alloys capable of withstanding the rigorous conditions required according to other variants of the invention are iron-aluminum-chromium alloys which may also contain yttrium. The latter alloys according to yet other variants may contain 0.5-12 wt.% Al, 0.1-3.0 wt.% Y, 0.20 wt.% Cr. and balance Fe. These are described in United States Patent No. 3,298,826. Another range of Fe-Cr-Al-Y alloys within other variants contain 0.5 - 4 wt.% Al, 0.5 - 3.0 wt.% Y, 20.0 -95.0 wt.% Cr and balance Fe and these are described in United States Patent No. 3,027,251.
`~
'~.~L,,, ~ - 6 b --.: -. :
~ . . - -.
` ``` 1~7S~7 Base metal alloys which also contain a platinum group metal comr ponent according to yet other variants are useful as a catalycic metal-lic monolith in very fierce oxidising conditions, for example in catalysis of the combustion in gas turbine enginr-~s. Such alloys are described in German DOS 2530245 and contain at least 40 wt.% Ni or at least 40 wt.% Co, a trace to 30 wt.%
Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru. The alloys may also contain from a trace to the percentage specified of any one or more of the following elements:- -% by we i ght Co 25 Ti 6 Al 7 Mo 20 2 Hf 2 Mn 2 Si 1.5 V 2.0 _ 7 _ .. - ~ , .
11~)75~7 S6 by weight B 0.15 C 0.05 Ta 10 Zr 3 Fe 20 Th and rare earth metals 3 or oxides l~here the metallic substrate is composed either substantially or s~lely Or platinum group metal it may according to another variant be in the form of an interwoven wire gauze or mesh or corrugated sheet or foil.
Where the metallic substrate is composed substantially of base metal it is preferably in the form of corrugated sheet or foil. These types of base metal monoliths are also described in German DOS 2450664 and they may be used in turbines according to the present invention. Such base metal monoliths may have deposited thereon according to other variants thereof ;
a first layer comprising an oxygen containing coating and a second and catalytic layer. The oxygen containing coating is usually present as an oxide selected from the group consisting of alumina, silica, titania, zirconia, hafnia, thoria, beryllia, magnesia, calcium oxide, strontium oxide, barium oxide, chromia, boria, scandium oxide, yttrium oxide and oxides of the lanthanides. Alternatively, by another variant, the oxygen in the first layer is present as an oxygen containing anion selected from the group consisting of chromate, phosphate, silicate and nitrate. The second catalytic layer may, for example, comprise a metal s~lected from the group consisting of Ru, Rh, Pd, .~ .
.
- ~ ' ~1~7517 Ir, ~'t, Au~ Ag, an alloy containing at least one of the ~etals and alloys containing at least one of the metals and a base metal. The first and second layers may be deposited or otherwise applied to the monolith as described in Canadian Patent No. 1,078,364 issued May 27, 1980.
Alternative catalytic monoliths for use in section (f) according to aspects of this invention are the following structures, namely, a catalyst comprising a metallic substrate having deposited thereon a surfaee coating consisting of one or more intermetallic compounds of the general formula A B where A is selected from the group consisting of Ru, Rh, Pd, lQ Ir, and Pt and B is selected from the group consisting of Al, Sc, Y, the lanthanides, Ri, Zr, Hf, V, Nb, and Ta and x and y are integral and may have values of 1 or more. The surface coating of intermetallic compoundsis, preferably, in the form of a thin film ranging in thickness from 2 to 15 microns.
Many compounds of the type A B are miscible with one another and structures in which the surface coatings deposited upon the metallic sub-strate contains more than one compound of the type A B are within the scope of this invention.
When the intermetallic compound is deposited in the form of a coating not more than 15 microns thick upon the surface of a metallic sub-strate, excessive brittleness is absent and the coa,ed substrate may be handled normally.
.
~1~75~7 A number of diffcrent techniques may be employed to produce a coating in the form of a thin film of intermetallic compound upon the surface of the metal metallic monolith. For examF?le, aluminum may be depositcd onto the surface of rhodium-platinum gauzes by a pack-slumirising process. In this process the gauzes are packed into a heat-resistant container in an appropriate mixture of chemicals such that alumirn,m is transferred via the v~pour phase to the g~uze surface.
At the aluminising temperature, typically 800-900 C, interaction between ths platinum and aluminum occurs to give the required intermetallic compound Alternatively, chemical vapour deposition from ZrG14 can be used to form a layer of Pt3Zr, or electrodeposition may be used either from aqueous or fused salt electrolysis to give the requisite compound.
Whichever process is adopted the objective is to form a layer of a firmly adherent, intermetallic compound on the wires of the gauze pack or other substrate.
In another technique, the metals forming the intermetallic compound are prepared as an aporopriate solution in water or an organic solvent. The compound is caused to deposit upon the metallic substrate or gauze by the addition of a reducing agent.
The m etal I ic substrate is placed in the solution whilst the precipitation is taking place and becomes coatea with a uniform, microcrystalline layer of the interm etal I ic compound .
. ' . .
i'r~U'c~ LIIC r~ct i~ cl~ nl)~l (g) cu~ .lins .I L l.uff bo(ly wllk:ll ., ~ t~ f~ t ~,r ~ L~ r~.lctioll initi~lL~ tll~ _ caL,l.lyLic con~l)ustol~ ~eCL.ioll (I ).
Suit.lble blurL l)odios accorclillg to variants of tllis invention are fal)ricated ~rom ~lle same matcrials as the temperature stable and oxidation resistallt metallic monolitll of section (f). The compositions of such alloys are detcliled in full above and examples of alloys we have found to be useful are those known by the Trade marks of Inconel 600 and 601. The Nimonic alloys, Incoloy 800 and the Nichrome alloys (Registered 10 Trade Marks), stainless steels and platinum group metals may also be used. r In the accompanying drawings, Figure 1 is a diagrammatic cross section of a preferred embodiment including an optional variable vane fluid (air) control system;
- and Figure 2 shows a different engine grometry showing a fluid flow control system in which variable vanes are not used is shown.
r - In Figure 1 a compressor turbine (which is not shown) produces hot compressot feed air indicated by and moving in the direction indicated by arrow F.
Section (b) of the turbine as defined above may include a variable vane system for controliing the flow of F (preburner air) F2 (preburner di!ution air) and F3 (by-pass air). From Figure 1 it will be seen that . ~ ,.................................................................... ~
' -~ .
~llfJ7S:17 the flow F1 is dirccted lo a preburner injector lland the igni tor L, whercas the flows F2 and F3 by-passIt and L 1. During start up flows F2 and F3 are quite low and nearly all of the incoming hot compressor feed air F passes the preburnerI 1 and injector L1 On ignition the flow F2 and/or the fuel injectorl can be adjusted to produce temperatures of the flow F4 (i.e. F1+ F2) suitable for main burner ignition by igniting I2 and, consequently, optimum performaace. When these cor,ditions are achieved, the main burner in section (e) may be started and the flow F2 will be unrestricted. In these conditions, a flow F6 (which is controlled by operation of variable vanes V2) is also permitted and the quantity of fuel injected by main injector ~-2 is adjusted such.that diluted power turbine feed F8 is at the desired gas temperature for optimum performance. The start up will normally reach ignition prior to the end of "engine-cranking", but self-sustaining speed may not yet be achieved -and "engine-cranking" may be continued to that speed. The flow F3 provides wall cooling and blade cooling contact air if required.
Heated gas from diluted preburner (pilot burner) exhaust is mixed with air in chamber (d) as defined above and fed at sufficient temperature to the main catalytic combustor (f) where it mixes with fuel from injector I2 (e) and passes over the catalyst monolith C. The catalyst C
burns some or all of the fuel and any remainder is burnt by free radical reaction immediately downstream of the catalyst. Further dilution is - .
,;~,,-.- - -`::
available by introduction of air from the flow F3 if necessary. Further, a large flow F6 ignited by an emergency igniter I3 provides emergency power as required.
Throttle response is achieved by control of fuel injection and by sequenced operation of igniters Il and I2.
A variable vane system is not essential and in Figure 2 (where the same reference symbols are used) an alternative geometry is depicted in which division of the air flow is accomplished by geometric fluidic control.
T is a temperature probe which is connected via a feedback circuit to con-trol injector Il, in Figures 1 and 2 an optional bluff body is indicatedby reference B.
In a preferred embodiment, four separate fuel injections are used in the pilot burner stage (c) spaced from each other at angles of 90C
`` in the vertical plane shown at position Il in Figure 2. Similarly a multi-injection array may be used in place of the single injection shown at I2 in Figure 2.
EXAMPLE
~- The turbine used as a Rover/Lucas 60 b.h.p. simple cycle turbine on a Heenan and Froude G type dynamometer. The analytical equipment used was the following:
Gas Detector Method CO, C02 Non-dispersive infra red (Analytical Development Ltd.) HC Flame ionisation detector (IP~I) NO Luminox 201 (BOC) Oz Servomex.
~,................ .
75~7 Cllromel-A]tlmel thermocouples llnked to an MBM high speed data logger and punch unit were used for tcmperature measurement. Fuel consump-tion was determined by gravimetric systems and air consumption by venturi depression metering. Commercially available diesel fuel (DERV) was used.
The engine was run itially with the production flame combustor to determine the normal parameters. The results aré given in Table 1.
The exhaust gas analyses obtained for these runs are given in Table 2. On the basis of the idle and emergency power settings, the emission index for each gas was calculated and these figures are given in Table 3.
The standard combustor was then replaced by the catalytic system described above and shown in diagrammatic form in Figure 2. An idle test was performed under the same conditions as for the flame combustor. The exhaust analysis for the catalytic combustor is given in Table 4, together with the emission index figures.
During this catalyst test it was observed that the fuel injection system was delivering a mixture to the catalyst which was toorich. De-spite this, however, the emission index is considerably below that recorded for the flame combustion engine.
.".. ~ . . . .
.
1~7517 The catalyst used as a 400 cell per square inch Fecralloy (Regi6-tered Trade Mark) metallic monolith substrate having a wall thickne6s of 0.002 lnches. Washcoat used was 5 parts Kaiser "SAM" alumina to 1 part barium stabilized "Sol-Gel" alumina (UKAEA) at a loading of lg per cubic inch of monolith. Platinum was deposited on the washcoàt by known techniques at a loading of 150g per cubic foot of washcoated monolith.
A Kanthal D (Registered Trade Mark) metallic monolith substrate also having a wall thickness of 0.002 inches may replace the Fecralloy substrate in this test.
`75~7 Tsble 1.
Dat _ r m~ turbine runninR with production flame combustor Test Condition * 1 2 3 4 5 Brake load (relative) 10 40 70 95.2 10 Time to consume 21. fuel (sec)230 201167 145 230 Impellor tip press.(p.s.i.g.) 3.4 3.63.7 3.8 3.5 Compressor delivery press. (p.s.i.g.) 26 26.627.9 28.1 26 Compressor delivery press. (p.s.i.a.) 41 41.642.9 43.1 41 Combustor back press. (cm.Hg)15.5 15.714.4 14.015.7 Exhaust press. (cm.H20) 5.3 3.22.0 -2.3 4.3 Air venturi depression (cm.H20)24.6 22.422.0 20.524.5 Air temp. ((F) 68 68 68 68 68 Jet Pipe temp (C) 385 453535 594 378 * 1 = sustaining idle; 2 = mid-power, 3 = baseline power, 4 = emergency power; 5 = idle - Table 2.
Exhaust Analysis Test No. 1 2 3 4 5 HC ppm 350 180150 140 360 N0 ppm 13 22 33 44 17 N0 ppm 22 24 42 58 18 CO ppm 1450 - 150 97 1121560 2% ~ 2.5 3 3.7 4.5 2.4 ; 2 % 18 17.5 16.7 15.7 18.
., ~1~75~7 Table 3.
F~iseio= 1ndices in g/k~ Fuel Test No. 1 4 HC 53.4 12.26 N0 1.5 2.82 N0 2.3 3,72 C0 150.0 6.24 Table 4.
Exhaust analysis and emission index figures for catalYtic combustor 10 Exhaust Analysis Emission Index (g/kg. fuel) HC 30 ppm 4.5 N0 1 0.11 N0x 1 0.11 C0 150 15.5 .
. ~
.
, -
Claims (21)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A gas turbine engine including a catalytic combustor, the catalytic combustor comprising:
(a) a pilot burner adapted to consume not more than 5% of the total fuel consumption of the engine at full power;
(b) a combining chamber for combining and mixing effluent hot gases from the pilot burner with additional hot compressed air at a pressure within the range 1 - 20 atmospheres de-livered from a compressor turbine, said chamber having an in-let to receive said effluent hot gases and the hot compressed air, and an exit to discharge therefrom the combined hot gases;
(c) an injector capable, under full power conditions, of in-jecting a major portion of the total fuel requirement directly into said combined hot gases leaving the said chamber; and (d) a thermally stable and oxidation-resistant metallic mono-lith containing a multiplicity of flow paths or channels whose surfaces possess catalytic activity such that catalytic com-bustion of combustible gases and injected fuel may take place, the walls of said metallic monolith possessing a thickness within the range 0.002 to 0.004 inch.
(a) a pilot burner adapted to consume not more than 5% of the total fuel consumption of the engine at full power;
(b) a combining chamber for combining and mixing effluent hot gases from the pilot burner with additional hot compressed air at a pressure within the range 1 - 20 atmospheres de-livered from a compressor turbine, said chamber having an in-let to receive said effluent hot gases and the hot compressed air, and an exit to discharge therefrom the combined hot gases;
(c) an injector capable, under full power conditions, of in-jecting a major portion of the total fuel requirement directly into said combined hot gases leaving the said chamber; and (d) a thermally stable and oxidation-resistant metallic mono-lith containing a multiplicity of flow paths or channels whose surfaces possess catalytic activity such that catalytic com-bustion of combustible gases and injected fuel may take place, the walls of said metallic monolith possessing a thickness within the range 0.002 to 0.004 inch.
2. A gas turbine engine comprising:
(a) a compressor turbine for producing a supply of hot com-pressed air at a pressure within the range 1-20 atmospheres to a combustor section;
(b) means for take-off and by-pass of a major proportion of the air flow said means being disposed subsequent to the compressed air inlet from the compressor turbine;
(c) a pilot burner fuelled by a fuel injector and adapted to consume not more than approximately 5% of the total fuel con-sumption of the engine at full power;
(d) a combining chamber for combining the hot gas effluent from said pilot burner (c) with a proportion of the hot com-pressed air removed at stage (b);
(e) an injector capable, under full power conditions, of in-jecting at least a major portion of the total fuel requirement directly into the effluent hot gases exiting from chamber (d);
(f) a catalytic combustor section comprising a temperature stable and oxidation resistant metallic monolith, said metallic monolith having walls possessing a thickness within the range 0.002 - 0.004 inches and providing catalytic channels for con-tact with and passage therethrough of the combusting gases com-bined with injected fuel at stage (e) such that combustion of a substantial proportion of the uncombusted fuel takes place but in which a pressure drop not greater than 10% is produced;
(g) a reaction chamber subsequent to the catalytic combustor section in which combustion continues; and (h) a gas generator turbine which may be engaged in a mechanical-ly rigid manner to said compressor turbine and which is driven by expansion of the hot combusting gases produced by said en-gine.
(a) a compressor turbine for producing a supply of hot com-pressed air at a pressure within the range 1-20 atmospheres to a combustor section;
(b) means for take-off and by-pass of a major proportion of the air flow said means being disposed subsequent to the compressed air inlet from the compressor turbine;
(c) a pilot burner fuelled by a fuel injector and adapted to consume not more than approximately 5% of the total fuel con-sumption of the engine at full power;
(d) a combining chamber for combining the hot gas effluent from said pilot burner (c) with a proportion of the hot com-pressed air removed at stage (b);
(e) an injector capable, under full power conditions, of in-jecting at least a major portion of the total fuel requirement directly into the effluent hot gases exiting from chamber (d);
(f) a catalytic combustor section comprising a temperature stable and oxidation resistant metallic monolith, said metallic monolith having walls possessing a thickness within the range 0.002 - 0.004 inches and providing catalytic channels for con-tact with and passage therethrough of the combusting gases com-bined with injected fuel at stage (e) such that combustion of a substantial proportion of the uncombusted fuel takes place but in which a pressure drop not greater than 10% is produced;
(g) a reaction chamber subsequent to the catalytic combustor section in which combustion continues; and (h) a gas generator turbine which may be engaged in a mechanical-ly rigid manner to said compressor turbine and which is driven by expansion of the hot combusting gases produced by said en-gine.
3. A gas turbine according to claims 1 or 2 in which said injector is positioned directly in the path of the hot combined gases leaving said combining chamber.
4. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal.
5. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is made from 10% rhodium/platinum alloy.
6. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is made from a nickel/chromium alloy having an aggregate Ni plus Cr content greater than 20% by weight.
7. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is made from an alloy of iron including at least one of the elements chromium (3-40) wt.%, aluminum (1-10) wt.%, cobalt (trace-5) wt.%, nickel (trace-72) wt.% and carbon (trace-0.5) wt.%.
8. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is made from an alloy comprising 0.5-12 wt.%, Al, 0.1-3.0 wt.% Y, 0-20 wt.% Cr and balance Fe.
9. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is made from an alloy comprising 0.5-4 wt.% Al, 0.5-3.0 wt.% Y, 20.0-95.0 wt.% Cr and balance Fe.
10. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is made from an alloy comprising at least 40 wt.% Ni or at least 40 wt.% Co, a trace to 30 wt. % Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru.
11. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is made from an alloy comprising at least 40 wt.% Ni or at least 40 wt.% Co, a trace to 30 wt.% Cr and a trace to 15 wt.% of one or more of the metals Pt, Pd, Rh, Ir, Os and Ru and further containing from a trace to the percentage specified of at least one of the following elements:
% by weight Co 25 Ti 6 Al 7 Mo 20 % by weight Hf 2 Mn 2 Si 1.5 V 2.0 Nb 5 B 0.15 C 0.05 Ta 10 Zr 3 Fe 20 Th and rare earth metals 3 or oxides
% by weight Co 25 Ti 6 Al 7 Mo 20 % by weight Hf 2 Mn 2 Si 1.5 V 2.0 Nb 5 B 0.15 C 0.05 Ta 10 Zr 3 Fe 20 Th and rare earth metals 3 or oxides
12. A gas turbine engine according to Claims 1 or 2 wherein the metallic monolith is in the form of an interwoven wire gauze, mesh, or cor-rugated sheet, or foil.
13. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer.
14. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and fur-ther wherein said first layer is an oxide selected from the group consisting of alumina, silica, titania, zirconia, hafnia, thoria, beryllia, magnesia, calcium oxide, strontium oxide, barium oxide, chromia, boria, scandium oxide, yttrium oxide and oxides of the lanthanides.
15. A gas turbine enzyme according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and fur-ther wherein said first layer is an oxygen-containing anion selected from the group consisting of chromate, phosphate, silicate and nitrate.
16. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and wherein said second catalytic layer is a metal selected from the group con-sisting of Ru, Rh, Pd, Ir, Pt, Au, Ag, an alloy containing at least one of the said metals and alloys containing at least one of the said metals and a base metal.
17. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and fur-ther wherein said first layer is an oxide selected from the group consisting of alumina, silica, titania, zirconia, hafnia, thoria, beryllia, magnesia, calcium oxide, strontium oxide, barium oxide, chromia, boria, scandium oxide, yttrium oxide and oxides of the lanthanides and wherein said second catalytic layer is a metal selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ag, an alloy containing at least one of the said metals and alloys con-taining at least one of the said metals and a base metal.
18. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and fur-ther wherein said first layer is an oxygen-containing anion selected from the group consisting of chromate, phosphate, silicate, and nitrate and wherein said second catalytic layer is a metal selected from the group con-sisting of Ru, Rh, Ir, Pt, Au, Ag, an alloy containing at least one of the said metals and alloys containing at least one of the said metals and a base metal.
19. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys containing a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and wherein said second catalytic layer comprises at least one inter-metallic compounds of the general formula AxBy, where A is selected from the group consisting ofRu, Rh, Pd, Ir, and Pt, wherein B is selected from the group consisting of Al, Se, Y, the lanthanides, Ti, Zr, Hf, V, Nb, and Ta, and wherein x and y are integral and may have values of 1 or more.
20. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys con-taining a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and fur-ther wherein said first layer is an oxide selected from the group consisting of alumina, silica, titania, zirconia, hafnia, thoria, beryllia, magnesia, calcium oxide, strontium oxide, barium oxide, chromia, boria, scandium,oxide, yttrium oxide and oxides of the lanthanides and wherein said second catalytic layer comprises at least one intermetallic compounds of the general formula AxBy, wherein A is selected from the group consisting of Ru, Rh, Pd, Ir, and Pt, wherein B is selected from the group consisting of Al, Se, Y, the lanthanides, Ti, Zr, HF, V, Nb, and Ta, and wherein x and y are integral and may have values of 1 or more.
21. A gas turbine engine according to Claims 1 or 2 wherein said metallic monolith is formed from at least one metal selected from the group consisting of Ru, Rh, Pd, Ir and Pt base metals, and base metal alloys containing a platinum group metal and wherein said metallic monolith has a first layer of an oxygen containing material and a second catalytic layer and further wherein said first layer is an oxygen-containing anion selected from the group consisting of chromate, phosphate, silicate and nitrate and wherein said second catalytic layer comprises at least one intermetallic compounds of the general formula AxBy where A is selected from the group consisting of Ru, Rh, Pd, Ir, and Pt, wherein B is selected from the group consisting of Al, Se, Y, the lanthanides, Ti, Zr, Hf, V, Nb, and Ta, and wherein x and y are integral and may have values of 1 or more.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9238/77 | 1977-03-04 | ||
| GB923877A GB1601687A (en) | 1977-03-04 | 1977-03-04 | Gas turbine engines |
| GB3619177 | 1977-08-30 | ||
| GB36191/77 | 1977-08-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1107517A true CA1107517A (en) | 1981-08-25 |
Family
ID=26242811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA298,126A Expired CA1107517A (en) | 1977-03-04 | 1978-03-03 | Catalysis |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS53131314A (en) |
| CA (1) | CA1107517A (en) |
| DE (1) | DE2809407A1 (en) |
| FR (1) | FR2382584A1 (en) |
| SE (1) | SE7802205L (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5326253A (en) * | 1990-11-26 | 1994-07-05 | Catalytica, Inc. | Partial combustion process and a catalyst structure for use in the process |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2500064B2 (en) * | 1981-02-17 | 1985-11-08 | Snecma | DEVICE FOR IGNITING FUEL INJECTED INTO A FAST FLOW GAS MEDIUM |
| CA1191703A (en) * | 1981-11-02 | 1985-08-13 | Daniel E. Carl | Combustion turbine combustor having an improved heavy- oil fuel preparation zone |
| JPS60175925A (en) * | 1984-02-23 | 1985-09-10 | Toshiba Corp | Catalytic combustion |
| DE3474714D1 (en) * | 1983-12-07 | 1988-11-24 | Toshiba Kk | Nitrogen oxides decreasing combustion method |
| US5250489A (en) * | 1990-11-26 | 1993-10-05 | Catalytica, Inc. | Catalyst structure having integral heat exchange |
| ATE176605T1 (en) * | 1990-11-26 | 1999-02-15 | Catalytica Inc | PALLADIUM CATALYSTS FOR INCOMPLETE COMBUSTION AND METHOD OF USE THEREOF |
| US5259754A (en) * | 1990-11-26 | 1993-11-09 | Catalytica, Inc. | Partial combustion catalyst of palladium on a zirconia support and a process for using it |
| DE10061527A1 (en) | 2000-12-11 | 2002-06-13 | Alstom Switzerland Ltd | Premix burner assembly with catalytic combustion and method of operation therefor |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1077510A (en) * | 1951-06-04 | 1954-11-09 | Catalytic combustion chambers by liquid injection and gas transmission | |
| US3032991A (en) * | 1959-10-01 | 1962-05-08 | Gen Electric | Combustion sustaining means for continuous flow combustion systems |
| SE431669B (en) * | 1971-07-21 | 1984-02-20 | Engelhard Corp | COMPLETE COMPLETE AND WITHOUT PREVENTION OF OXIDATION OF ATMOSPHERIC COMBUSTION CARBON FUEL |
| DE2232506C2 (en) * | 1972-07-03 | 1982-03-25 | Siemens AG, 1000 Berlin und 8000 München | Method and device for generating a gas mixture to be formed by the catalytic conversion of fuel and a gas serving as an oxygen carrier |
| US3938326A (en) * | 1974-06-25 | 1976-02-17 | Westinghouse Electric Corporation | Catalytic combustor having a variable temperature profile |
-
1978
- 1978-02-27 SE SE7802205A patent/SE7802205L/en unknown
- 1978-03-02 FR FR7805951A patent/FR2382584A1/en not_active Withdrawn
- 1978-03-03 CA CA298,126A patent/CA1107517A/en not_active Expired
- 1978-03-04 JP JP2407478A patent/JPS53131314A/en active Pending
- 1978-03-04 DE DE19782809407 patent/DE2809407A1/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5326253A (en) * | 1990-11-26 | 1994-07-05 | Catalytica, Inc. | Partial combustion process and a catalyst structure for use in the process |
| US5511972A (en) * | 1990-11-26 | 1996-04-30 | Catalytica, Inc. | Catalyst structure for use in a partial combustion process |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS53131314A (en) | 1978-11-16 |
| DE2809407A1 (en) | 1978-09-07 |
| SE7802205L (en) | 1978-09-05 |
| FR2382584A1 (en) | 1978-09-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |