EP1722164A1 - Fuel injection apparatus - Google Patents
Fuel injection apparatus Download PDFInfo
- Publication number
- EP1722164A1 EP1722164A1 EP06009563A EP06009563A EP1722164A1 EP 1722164 A1 EP1722164 A1 EP 1722164A1 EP 06009563 A EP06009563 A EP 06009563A EP 06009563 A EP06009563 A EP 06009563A EP 1722164 A1 EP1722164 A1 EP 1722164A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- flow
- fuel
- fuel injection
- swirl
- annular member
- 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.)
- Withdrawn
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C7/00—Combustion apparatus characterised by arrangements for air supply
- F23C7/002—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion
- F23C7/004—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion using vanes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
- F23D11/10—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour
- F23D11/106—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour medium and fuel meeting at the burner outlet
- F23D11/107—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour medium and fuel meeting at the burner outlet at least one of both being subjected to a swirling motion
-
- 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
- F23R3/02—Continuous combustion chambers using liquid or gaseous fuel characterised by the air-flow or gas-flow configuration
- F23R3/04—Air inlet arrangements
- F23R3/10—Air inlet arrangements for primary air
- F23R3/12—Air inlet arrangements for primary air inducing a vortex
- F23R3/14—Air inlet arrangements for primary air inducing a vortex by using swirl vanes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
- F23D2900/11101—Pulverising gas flow impinging on fuel from pre-filming surface, e.g. lip atomizers
Definitions
- the present invention relates to a fuel injection apparatus, in particular for aircraft gas turbine engines, comprising a central channel which extends at least between a fuel injection means and an injection opening to a combustion chamber and forms a diffuser at said injection opening, wherein said fuel injection means is adapted to spray liquid fuel across a primary flow of gaseous oxidation medium onto the radially inner surface of a generally annular member downstream of said fuel injection means to form a fuel film flow in a generally downstream direction over said surface, a downstream end of said annular member terminating in an annular lip.
- the fuel injection apparatus further comprises swirl generation means applying a swirl to the primary flow of gaseous oxidation medium and means for directing a secondary flow of gaseous oxidation medium, a mass flow of which is equal or higher than a mass flow of the primary flow, over the radially outer surface of said annular member to cooperate with said primary flow to provide atomization of said fuel film downstream of said annular lip.
- a gas turbine engine includes a compressor that provides pressurized air to a combustor wherein the air is mixed with fuel and ignited for generating hot combustion gases. This gases flow downstream to one ore more turbines said extract energy therefrom to power the compressor and provide useful work such as powering an aircraft in flight.
- the air is supplied through surrounding assemblies, known as swirl generators, which impart a swirling motion to the air so as to cause the air and fuel to be thoroughly mixed.
- a main object of the continuing development of fuel injection systems for gas turbines is the improvement of the efficiency which requires an increased pressure and temperature level within the combustion chamber. These increased levels, however, also result in an increased emission of undesired oxides of nitrogen. Such oxides are considered as harmful emissions which should be reduced.
- One known way to reduce the emission of oxides of nitrogen is the optimization of the mixing of the liquid fuel with the air which is fed into the combustion chamber for combustion purposes. If the fuel is poorly atomized and evaporated so said liquid fuel droplets remain or if local areas of high fuel concentration occur, the combustion temperature increases locally. This in turn results in a correspondingly increased rate in the production of the oxides of nitrogen.
- the proposed fuel injection apparatus comprises a central channel extending at least between a fuel injection means and an injection opening to a combustion chamber, said central channel forming a diffuser at said injection opening.
- the fuel injection means is adapted to spray liquid fuel across a primary flow of gaseous oxidation medium, in particular air, onto the radially inner surface of a generally annular member downstream of the fuel injection means to form a fuel film flow in a generally downstream direction over said surface.
- the downstream end of said annular member terminates in an annular lip, also called atomizer lip.
- the apparatus further comprises a swirl generation means which applies a swirl to the primary flow of gaseous oxidation medium, and means for directing a secondary flow of gaseous oxidation medium, a mass flow of which is equal or higher than a mass flow of the primary flow, over the radially outer surface of the annular member to cooperate with said primary flow to provide atomization of said fuel film downstream of said annular lip.
- the annular lip preferably is arranged at a position of the central channel at which a smallest flow cross section of the primary and secondary flow of gaseous oxidation medium is achieved within the apparatus.
- the proposed fuel injection apparatus is characterized in that said diffuser formed of said central channel has a diffuser angle of s 15° and that said means for directing the secondary flow of gaseous oxidation medium to the radially outer surface of the annular member is designed to apply a swirl with a swirl number of lower than 0.2 to the secondary flow or to apply no swirl to the secondary flow.
- the present invention is based on the finding that with the generation of a lifted flame within the combustion chamber a better mixing between the liquid fuel and the oxidation medium is achieved.
- the lifted flame allows the mixing process to completely or partly take place within the combustion chamber prior to combustion.
- the two measures of the characterizing portion of claim 1 have to be taken.
- a further improvement in the generation of a lifted flame having a sufficiently high distance from the injection opening is achieved when the edges of the injection opening are designed as sharp edges.
- the further components of the fuel injection apparatus can be designed in the manner known in the art, for example as known from DE 196 27 760 A1 , which is included in the present patent application by reference.
- the primary flow of gaseous oxidation medium is supplied to the central channel preferably via a primary flow duct through a first discharge opening downstream of the fuel injection means, for example one or several spray nozzles.
- the discharge opening surrounds the central channel at this position.
- the secondary flow is preferably supplied via a secondary flow duct through a second discharge opening downstream of the first discharge opening, said second discharge opening also surrounding the central channel.
- the two discharge openings are separated by the annular member forming the annular lip.
- the swirl generation means for applying a swirl to the primary flow and, if applicable, to the secondary flow are arranged within the primary and the secondary flow duct.
- the diffuser is formed at the downstream end of the central channel by increasing the cross section of the central channel towards the combustion chamber. This can be a linear as well as a nonlinear increase resulting in a straight-line or, for example, a convex inner shape of the diffuser section. In case of a convex shape it is the tangent to this shape at the downstream end of the diffuser which must have an angle against the central axis of equal or less than 15° in order to fulfill the requirement of the present fuel injection apparatus.
- the central member terminating in the annular lip extends to a length in a flow direction of said primary flow, i.e. in a downstream direction of the central channel, which length is higher than the inner diameter of the opening formed by the angular lips.
- a length of the annular member in the downstream direction preferably is ⁇ 1.5 times of the inner diameter of the opening formed by the angular lip.
- a further improvement of the mixing of the liquid fuel and the oxidation medium is achieved with an elongation of the distance between the annular lip and the injection opening to the combustion chamber.
- a longer distance allows a longer time for mixing between the atomized liquid fuel and the oxidation medium which also results in a more homogeneous distribution of the fuel at the combustion region. If the distance is too large, the inner wall is wetted with liquid fuel, which again deteriorates the fuel distribution at the combustion region.
- the distance is selected as large as possible without wetting the inner wall of the central channel at the injection opening with liquid fuel.
- one or several fuel supply channels for liquid fuel are arranged, preferably symmetrically around the central channel, within the annular member.
- These additional fuel supply channels have discharge openings at the radially inner surface of this annular member upstream of the annular lip.
- the liquid fuel can be supplied through this additional fuel supply channels to the radially inner surface of the annular member in addition to the supply of fuel via the central fuel injection means or alternatively to this central injection.
- the liquid fuel is supplied through the central injection means during low load conditions of the gas turbine, whereas the liquid fuel is supplied through the additional fuel supply channel(s) during high load conditions of the turbine engine. This also leads to an improvement in the homogeneity of the fuel distribution in the combustion region.
- the following exemplary embodiment shows an example of the proposed fuel injection apparatus with reference to the accompanying figure without limiting the scope of the invention as defined in the claims.
- the figure shows an example of the fuel injection apparatus in a schematic view.
- the fuel injection apparatus shown in figure 1 can be used in a gas turbine engine, a section of which is shown for example in figure 1 of DE 196 27 760 A1 .
- the exemplary fuel injection apparatus comprises a central channel 13 which extends between a fuel spray nozzle 10 and an injection opening 14 to the combustion chamber 15 not explicitly shown in this figure.
- the fuel injection apparatus further comprises a primary flow duct 6 and a secondary flow duct 1 downstream of said primary flow duct 6.
- the two flow ducts 6, 1 are separated by a generally annular member 16 terminating in an annular lip 8 in the downstream direction.
- the flow ducts 1, 6 are formed concentrically to the central axis A of the central channel 13, which is the central axis of the radially symmetric fuel injection apparatus of the present example.
- a diffuser 5 is formed at the injection opening 14.
- the diffuser 5 is formed with a linear increasing cross section of the central channel 13.
- a intermediate section 12 having a constant diameter is provided between the diffuser 5 and the annular lip 8 .
- the length of this intermediate section 12 together with the length of the diffuser 5 in the flow direction is selected such that it is as long as possible without wetting of the inner wall of the diffuser 5 with liquid fuel droplets. This maximum length improves the mixing between the liquid fuel atomized at the annular lip 8 and the air flow due to a longer flight time of the fuel prior to combustion.
- Annular member 16 also comprises additional fuel channels 11 for supplying liquid fuel to the radially inner surface of the annular member 16.
- these fuel channels 11 are shown in the figure to be arranged vertically with respect to the central axis A, this is only exemplary. They can also be arranged at another angle with respect to the central axis A or can follow a curved line, preferably in order to enter the central channel 13 in flow direction nearly tangentially to the radially inner surface 7 of the annular member 16.
- swirl generators are arranged to apply a swirl to the primary flow 3 of air and to the secondary flow 2 of air which is supplied from the compressor stage of the gas turbine.
- the swirl generator in the secondary flow duct 1 is designed such that the swirl of the secondary flow 2 has a swirl rate of less than 0.2.
- the swirl directions of the primary flow 3 and secondary flow 2 can be co-rotating or counter-rotating. It is also possible to provide the secondary flow duct 1 without any swirl generator. In this case the secondary flow 2 is without any swirl.
- the cross sections of the primary duct 6 and the secondary duct 1 are such that the mass flow of the air through the secondary duct 1 is equal or greater than the mass flow of the air through the primary duct 6.
- liquid fuel 17 is sprayed by the fuel spray nozzle 10 to the radially inner surface 7 of the annular member 16 as indicated in the figure.
- the primary air flow 3 and secondary air flow 2 are supplied through the primary 6 and secondary duct 1 to the central channel 13. This is indicated by corresponding arrows in the figure.
- the liquid fuel 17 sprayed onto the inner surface 7 of the annular member 16 forms a thin film of liquid fuel on the surface 7 which moves downstream towards annular lip 8. Due to the shearing stream of the secondary flow 2 and the primary flow 3 at the edge of this annular lip 8 the fuel film tears off and at the same time is atomized and/or evaporated due to the shearing forces of the air flows.
- Annular lip 8 is arranged at the narrowest flow cross section or immediately before this narrowest flow cross section of the primary and secondary flow, i.e. at the position of highest flow velocities. This results in a maximum atomizing effect and leads to an optimum atomizing of the liquid fuel.
- the combustion flame forms not immediately at the injection opening 14 in the combustion chamber 15, but at a downstream distance from this injection opening.
- a flame which is not attached to the injection opening is called a lifted flame.
- the sharp edges 4 of the injection opening furthermore improve the formation of such a lifted flame.
- the distance between the lifted flame and the injection opening 14 is large enough to enable a significant further mixing of the atomized fuel with the air prior to combustion, which results in a more homogeneous distribution of the fuel at the combustion region.
- the liquid fuel 17 is sprayed by the fuel spray nozzle 10 onto the radially inner surface 7 of the annular member 16 during low load operation of the gas turbine.
- the fuel is not supplied via the central fuel spray nozzle 10 but through the additional fuel supply channels 11 in order to achieve a more reliable wetting of the inner surface 7 of the annular member 16 at this load.
- the preferably concentrically arranged fuel supply channels 11 can nevertheless also be operated at the same time as the fuel spray nozzle 10 and vice versa.
- the length L of the annular member 16 in flow direction is larger than the diameter D of annular lip 8 at the downstream end of the annular member 16. This results in a longer distance available for the evaporation of the liquid fuel sprayed onto the inner surface 7 of the annular member 16. Therefore, the mixing of air and liquid fuel is further improved by this measure.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Spray-Type Burners (AREA)
- Nozzles For Spraying Of Liquid Fuel (AREA)
Abstract
Description
- The present invention relates to a fuel injection apparatus, in particular for aircraft gas turbine engines, comprising a central channel which extends at least between a fuel injection means and an injection opening to a combustion chamber and forms a diffuser at said injection opening, wherein said fuel injection means is adapted to spray liquid fuel across a primary flow of gaseous oxidation medium onto the radially inner surface of a generally annular member downstream of said fuel injection means to form a fuel film flow in a generally downstream direction over said surface, a downstream end of said annular member terminating in an annular lip. The fuel injection apparatus further comprises swirl generation means applying a swirl to the primary flow of gaseous oxidation medium and means for directing a secondary flow of gaseous oxidation medium, a mass flow of which is equal or higher than a mass flow of the primary flow, over the radially outer surface of said annular member to cooperate with said primary flow to provide atomization of said fuel film downstream of said annular lip.
- A gas turbine engine includes a compressor that provides pressurized air to a combustor wherein the air is mixed with fuel and ignited for generating hot combustion gases. This gases flow downstream to one ore more turbines said extract energy therefrom to power the compressor and provide useful work such as powering an aircraft in flight. The air is supplied through surrounding assemblies, known as swirl generators, which impart a swirling motion to the air so as to cause the air and fuel to be thoroughly mixed.
- A main object of the continuing development of fuel injection systems for gas turbines is the improvement of the efficiency which requires an increased pressure and temperature level within the combustion chamber. These increased levels, however, also result in an increased emission of undesired oxides of nitrogen. Such oxides are considered as harmful emissions which should be reduced.
- One known way to reduce the emission of oxides of nitrogen is the optimization of the mixing of the liquid fuel with the air which is fed into the combustion chamber for combustion purposes. If the fuel is poorly atomized and evaporated so said liquid fuel droplets remain or if local areas of high fuel concentration occur, the combustion temperature increases locally. This in turn results in a correspondingly increased rate in the production of the oxides of nitrogen.
- In order to improve the mixing of the liquid fuel with the gaseous oxidation medium like air it is known to use air atomizer nozzles in the burner stages of gas turbines. An example of such a fuel injection apparatus according to the introductory portion of present claim 1 is disclosed in
DE 196 27 760 A1 . In this fuel injection apparatus a swirl of the same direction is applied to the primary and to the secondary flow of gaseous oxidation medium. The annular lip is arranged at a position of the central channel which provides the smallest flow cross section of the primary and secondary flow of gaseous oxidation medium within the apparatus, resulting in an optimized atomization of the fuel. A similar fuel injection apparatus is shown inEP 1 158 246 A2 , which discloses the generation of counter rotating swirls of the two flows of oxidation medium. - When using such known injection apparatuses in gas turbine engines, the mixing of liquid fuel and oxidation medium is not yet satisfactory resulting in a locally and temporally inhomogeneous distribution of liquid fuel and oxidation medium in the combustion chamber. This gives rise to an undesired inhomogeneous temperature distribution. In other words, locally confined stoichiometric regions can not be avoided even during combustion with an excess of oxygen, which due to their high temperatures cause a high production rate of harmful oxides of nitrogen.
- It is an object of the present invention to provide a fuel injection apparatus which achieves a more homogeneous distribution of liquid fuel and oxidation medium in the combustion region.
- The object is achieved with the fuel injection apparatus according to claim 1. Advantageous embodiments of the fuel injection apparatus are subject matter of the dependent claims or are described in the subsequent part of the description and preferred embodiments.
- The proposed fuel injection apparatus comprises a central channel extending at least between a fuel injection means and an injection opening to a combustion chamber, said central channel forming a diffuser at said injection opening. The fuel injection means is adapted to spray liquid fuel across a primary flow of gaseous oxidation medium, in particular air, onto the radially inner surface of a generally annular member downstream of the fuel injection means to form a fuel film flow in a generally downstream direction over said surface. The downstream end of said annular member terminates in an annular lip, also called atomizer lip. The apparatus further comprises a swirl generation means which applies a swirl to the primary flow of gaseous oxidation medium, and means for directing a secondary flow of gaseous oxidation medium, a mass flow of which is equal or higher than a mass flow of the primary flow, over the radially outer surface of the annular member to cooperate with said primary flow to provide atomization of said fuel film downstream of said annular lip. The annular lip preferably is arranged at a position of the central channel at which a smallest flow cross section of the primary and secondary flow of gaseous oxidation medium is achieved within the apparatus. The proposed fuel injection apparatus is characterized in that said diffuser formed of said central channel has a diffuser angle of s 15° and that said means for directing the secondary flow of gaseous oxidation medium to the radially outer surface of the annular member is designed to apply a swirl with a swirl number of lower than 0.2 to the secondary flow or to apply no swirl to the secondary flow.
- The present invention is based on the finding that with the generation of a lifted flame within the combustion chamber a better mixing between the liquid fuel and the oxidation medium is achieved. The lifted flame allows the mixing process to completely or partly take place within the combustion chamber prior to combustion. In order to allow the generation of such a lifted flame - in contrast to the normally arising attached flame - at a distance from the injection opening which is sufficient to achieve a more homogeneous mixing, the two measures of the characterizing portion of claim 1 have to be taken. A further improvement in the generation of a lifted flame having a sufficiently high distance from the injection opening is achieved when the edges of the injection opening are designed as sharp edges. The further components of the fuel injection apparatus can be designed in the manner known in the art, for example as known from
DE 196 27 760 A1 , which is included in the present patent application by reference. - In the present fuel injection apparatus the primary flow of gaseous oxidation medium is supplied to the central channel preferably via a primary flow duct through a first discharge opening downstream of the fuel injection means, for example one or several spray nozzles. The discharge opening surrounds the central channel at this position. In the same manner the secondary flow is preferably supplied via a secondary flow duct through a second discharge opening downstream of the first discharge opening, said second discharge opening also surrounding the central channel. The two discharge openings are separated by the annular member forming the annular lip. The swirl generation means for applying a swirl to the primary flow and, if applicable, to the secondary flow are arranged within the primary and the secondary flow duct.
- The diffuser is formed at the downstream end of the central channel by increasing the cross section of the central channel towards the combustion chamber. This can be a linear as well as a nonlinear increase resulting in a straight-line or, for example, a convex inner shape of the diffuser section. In case of a convex shape it is the tangent to this shape at the downstream end of the diffuser which must have an angle against the central axis of equal or less than 15° in order to fulfill the requirement of the present fuel injection apparatus.
- In a further improved embodiment the central member terminating in the annular lip extends to a length in a flow direction of said primary flow, i.e. in a downstream direction of the central channel, which length is higher than the inner diameter of the opening formed by the angular lips. Such an elongated annular member allows evaporation of a higher portion of the liquid fuel applied to the annular member and results in a more homogeneous distribution of the liquid fuel in the oxidation medium already within the fuel injection apparatus. The length of the annular member in the downstream direction preferably is ≥ 1.5 times of the inner diameter of the opening formed by the angular lip.
- A further improvement of the mixing of the liquid fuel and the oxidation medium is achieved with an elongation of the distance between the annular lip and the injection opening to the combustion chamber. A longer distance allows a longer time for mixing between the atomized liquid fuel and the oxidation medium which also results in a more homogeneous distribution of the fuel at the combustion region. If the distance is too large, the inner wall is wetted with liquid fuel, which again deteriorates the fuel distribution at the combustion region. In a preferred embodiment of the proposed fuel injection apparatus, the distance is selected as large as possible without wetting the inner wall of the central channel at the injection opening with liquid fuel.
- In a further advantageous embodiment of the present fuel injection apparatus one or several fuel supply channels for liquid fuel are arranged, preferably symmetrically around the central channel, within the annular member. These additional fuel supply channels have discharge openings at the radially inner surface of this annular member upstream of the annular lip. The liquid fuel can be supplied through this additional fuel supply channels to the radially inner surface of the annular member in addition to the supply of fuel via the central fuel injection means or alternatively to this central injection. Preferably the liquid fuel is supplied through the central injection means during low load conditions of the gas turbine, whereas the liquid fuel is supplied through the additional fuel supply channel(s) during high load conditions of the turbine engine. This also leads to an improvement in the homogeneity of the fuel distribution in the combustion region. At high load conditions it could occur that not all of the liquid fuel supplied through the central injection means reach the inner surface of the annular member resulting in a poorer atomization. At this high load conditions, however, the fuel can be reliably supplied to this surface through the additional fuel supply channels arranged inside of the annular member.
- The following exemplary embodiment,shows an example of the proposed fuel injection apparatus with reference to the accompanying figure without limiting the scope of the invention as defined in the claims. The figure shows an example of the fuel injection apparatus in a schematic view.
- The fuel injection apparatus shown in figure 1 can be used in a gas turbine engine, a section of which is shown for example in figure 1 of
DE 196 27 760 A1 . - The exemplary fuel injection apparatus comprises a
central channel 13 which extends between afuel spray nozzle 10 and an injection opening 14 to the combustion chamber 15 not explicitly shown in this figure. The fuel injection apparatus further comprises aprimary flow duct 6 and a secondary flow duct 1 downstream of saidprimary flow duct 6. The twoflow ducts 6, 1 are separated by a generallyannular member 16 terminating in an annular lip 8 in the downstream direction. Theflow ducts 1, 6 are formed concentrically to the central axis A of thecentral channel 13, which is the central axis of the radially symmetric fuel injection apparatus of the present example. - Upstream of the annular lip 8 a diffuser 5 is formed at the
injection opening 14. The diffuser 5 is formed with a linear increasing cross section of thecentral channel 13. Between the diffuser 5 and the annular lip 8 a intermediate section 12 having a constant diameter is provided. The length of this intermediate section 12 together with the length of the diffuser 5 in the flow direction is selected such that it is as long as possible without wetting of the inner wall of the diffuser 5 with liquid fuel droplets. This maximum length improves the mixing between the liquid fuel atomized at the annular lip 8 and the air flow due to a longer flight time of the fuel prior to combustion. -
Annular member 16 also comprises additional fuel channels 11 for supplying liquid fuel to the radially inner surface of theannular member 16. Although these fuel channels 11 are shown in the figure to be arranged vertically with respect to the central axis A, this is only exemplary. They can also be arranged at another angle with respect to the central axis A or can follow a curved line, preferably in order to enter thecentral channel 13 in flow direction nearly tangentially to the radially inner surface 7 of theannular member 16. - In the primary 6 and secondary duct 1 swirl generators (not shown) are arranged to apply a swirl to the primary flow 3 of air and to the
secondary flow 2 of air which is supplied from the compressor stage of the gas turbine. The swirl generator in the secondary flow duct 1 is designed such that the swirl of thesecondary flow 2 has a swirl rate of less than 0.2. The swirl directions of the primary flow 3 andsecondary flow 2 can be co-rotating or counter-rotating. It is also possible to provide the secondary flow duct 1 without any swirl generator. In this case thesecondary flow 2 is without any swirl. The cross sections of theprimary duct 6 and the secondary duct 1 are such that the mass flow of the air through the secondary duct 1 is equal or greater than the mass flow of the air through theprimary duct 6. - During operation of the fuel injection apparatus
liquid fuel 17 is sprayed by thefuel spray nozzle 10 to the radially inner surface 7 of theannular member 16 as indicated in the figure. At the same time the primary air flow 3 andsecondary air flow 2 are supplied through the primary 6 and secondary duct 1 to thecentral channel 13. This is indicated by corresponding arrows in the figure. Theliquid fuel 17 sprayed onto the inner surface 7 of theannular member 16 forms a thin film of liquid fuel on the surface 7 which moves downstream towards annular lip 8. Due to the shearing stream of thesecondary flow 2 and the primary flow 3 at the edge of this annular lip 8 the fuel film tears off and at the same time is atomized and/or evaporated due to the shearing forces of the air flows. Annular lip 8 is arranged at the narrowest flow cross section or immediately before this narrowest flow cross section of the primary and secondary flow, i.e. at the position of highest flow velocities. This results in a maximum atomizing effect and leads to an optimum atomizing of the liquid fuel. - Due to the low swirl of the
secondary flow 2 compared with the swirl of the primary flow 3 and to the small diffuser angle α of ≤ 15° the combustion flame forms not immediately at the injection opening 14 in the combustion chamber 15, but at a downstream distance from this injection opening. Such a flame which is not attached to the injection opening is called a lifted flame. The sharp edges 4 of the injection opening furthermore improve the formation of such a lifted flame. In the present embodiment the distance between the lifted flame and the injection opening 14 is large enough to enable a significant further mixing of the atomized fuel with the air prior to combustion, which results in a more homogeneous distribution of the fuel at the combustion region. - In the proposed injection apparatus the
liquid fuel 17 is sprayed by thefuel spray nozzle 10 onto the radially inner surface 7 of theannular member 16 during low load operation of the gas turbine. During high load operation the fuel is not supplied via the centralfuel spray nozzle 10 but through the additional fuel supply channels 11 in order to achieve a more reliable wetting of the inner surface 7 of theannular member 16 at this load. The preferably concentrically arranged fuel supply channels 11 can nevertheless also be operated at the same time as thefuel spray nozzle 10 and vice versa. - In the present example the length L of the
annular member 16 in flow direction is larger than the diameter D of annular lip 8 at the downstream end of theannular member 16. This results in a longer distance available for the evaporation of the liquid fuel sprayed onto the inner surface 7 of theannular member 16. Therefore, the mixing of air and liquid fuel is further improved by this measure. -
- 1
- secondary flow duct
- 2
- secondary flow of air
- 3
- primary flow of air
- 4
- sharp edges
- 5
- diffuser
- 6
- primary flow duct
- 7
- inner surface of annular member
- 8
- annular lip
- 9
- flow cross section
- 10
- fuel spray nozzle
- 11
- additional fuel supply channels
- 12
- intermediate section
- 13
- central channel
- 14
- injection opening
- 15
- combustion chamber
- 16
- annular member
- 17
- liquid fuel
Claims (6)
- Fuel injection apparatus, in particular for aircraft gas turbine engines, comprising- a central channel (13) which extends at least between a fuel injection means (10) and an injection opening (14) to a combustion chamber (15) and forms a diffuser (5) at said injection opening (14),wherein said fuel injection means (10) is adapted to spray liquid fuel (17) across a primary flow (3) of gaseous oxidation medium onto the radially inner surface (7) of a generally annular member (16) downstream of said fuel injection means (10) to form a fuel film flow in a generally downstream direction over said surface (7), a downstream end of said annular member (16) terminating in an annular lip (8),- swirl generation means applying a swirl to the primary flow (3) of gaseous oxidation medium and- means (1) for directing a secondary flow (2) of gaseous oxidation medium, a mass flow of which is equal or higher than a mass flow of the primary flow (3), over the radially outer surface of said annular member (16) to cooperate with said primary flow (3) to provide atomization of said fuel film downstream of said annular lip (8),characterized in that said diffuser (5) has a diffuser angle of equal or less than 15° and said means (1) for directing the secondary flow (2) of gaseous oxidation medium over the radially outer surface of said annular member (16) is designed to apply a swirl with a swirl number of < 0.2 or to apply no swirl to the secondary flow (2).
- Fuel injection apparatus according to claim 1, characterized in that said annular lip (8) is arranged at a position of said central channel (13) providing a smallest flow cross section of the primary (3) and secondary flow (2) of gaseous oxidation medium within the apparatus.
- Fuel injection apparatus according to claim 1 or 2, characterized in that said injection opening (14) has sharp edges (4).
- Fuel injection apparatus according to any of claims 1 to 3, characterized in that said annular lip (8) extends to a length in a flow direction of said primary flow (3) in the central channel (13) which is larger than an inner diameter of an opening formed by said annular lip (8).
- Fuel injection apparatus according to any of claims 1 to 4, characterized in that a distance between the annular lip (8) and the injection opening (14) is as large as possible without wetting an inner wall of the diffuser (5) with liquid fuel during operation.
- Fuel injection apparatus according to any of claims 1 to 5, characterized in that said annular member (16) at least one supply channel (11) for liquid fuel to the radially inner surface (7) of the generally annular member (16).
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE200510022772 DE102005022772A1 (en) | 2005-05-12 | 2005-05-12 | Burner with partial premixing and pre-evaporation of the liquid fuel |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1722164A1 true EP1722164A1 (en) | 2006-11-15 |
Family
ID=36616795
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP06009563A Withdrawn EP1722164A1 (en) | 2005-05-12 | 2006-05-09 | Fuel injection apparatus |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP1722164A1 (en) |
DE (1) | DE102005022772A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2223017A4 (en) * | 2007-11-21 | 2014-01-22 | Woodward Inc | Split-flow pre-filming fuel nozzle |
JP2014137193A (en) * | 2013-01-17 | 2014-07-28 | Hino Motors Ltd | Burner |
FR3057648A1 (en) * | 2016-10-18 | 2018-04-20 | Safran Helicopter Engines | LOW TURBOMACHINE COMBUSTION CHAMBER INJECTION SYSTEM |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007050276A1 (en) * | 2007-10-18 | 2009-04-23 | Rolls-Royce Deutschland Ltd & Co Kg | Lean premix burner for a gas turbine engine |
US8919132B2 (en) | 2011-05-18 | 2014-12-30 | Solar Turbines Inc. | Method of operating a gas turbine engine |
US8893500B2 (en) | 2011-05-18 | 2014-11-25 | Solar Turbines Inc. | Lean direct fuel injector |
US9182124B2 (en) | 2011-12-15 | 2015-11-10 | Solar Turbines Incorporated | Gas turbine and fuel injector for the same |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4842197A (en) * | 1986-12-10 | 1989-06-27 | Mtu Motoren-Und Turbinen-Union Gmbh | Fuel injection apparatus and associated method |
US5373693A (en) * | 1992-08-29 | 1994-12-20 | Mtu Motoren- Und Turbinen-Union Munchen Gmbh | Burner for gas turbine engines with axially adjustable swirler |
US5417070A (en) * | 1992-11-24 | 1995-05-23 | Rolls-Royce Plc | Fuel injection apparatus |
US5490378A (en) * | 1991-03-30 | 1996-02-13 | Mtu Motoren- Und Turbinen-Union Muenchen Gmbh | Gas turbine combustor |
DE19627760A1 (en) * | 1996-07-10 | 1998-01-15 | Mtu Muenchen Gmbh | Burner with atomizer nozzle |
US5966937A (en) * | 1997-10-09 | 1999-10-19 | United Technologies Corporation | Radial inlet swirler with twisted vanes for fuel injector |
US6543235B1 (en) * | 2001-08-08 | 2003-04-08 | Cfd Research Corporation | Single-circuit fuel injector for gas turbine combustors |
US20040219466A1 (en) * | 2003-05-02 | 2004-11-04 | Marino John A. | Aggregate dryer burner with compressed air oil atomizer |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1421399A (en) * | 1972-11-13 | 1976-01-14 | Snecma | Fuel injectors |
DE3608698A1 (en) * | 1986-01-18 | 1987-07-23 | Deutsche Forsch Luft Raumfahrt | BURNER BOILER UNIT |
DE4444961A1 (en) * | 1994-12-16 | 1996-06-20 | Mtu Muenchen Gmbh | Device for cooling in particular the rear wall of the flame tube of a combustion chamber for gas turbine engines |
FR2753779B1 (en) * | 1996-09-26 | 1998-10-16 | AERODYNAMIC INJECTION SYSTEM FOR A FUEL AIR MIXTURE | |
US6427435B1 (en) * | 2000-05-20 | 2002-08-06 | General Electric Company | Retainer segment for swirler assembly |
-
2005
- 2005-05-12 DE DE200510022772 patent/DE102005022772A1/en not_active Withdrawn
-
2006
- 2006-05-09 EP EP06009563A patent/EP1722164A1/en not_active Withdrawn
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4842197A (en) * | 1986-12-10 | 1989-06-27 | Mtu Motoren-Und Turbinen-Union Gmbh | Fuel injection apparatus and associated method |
US5490378A (en) * | 1991-03-30 | 1996-02-13 | Mtu Motoren- Und Turbinen-Union Muenchen Gmbh | Gas turbine combustor |
US5373693A (en) * | 1992-08-29 | 1994-12-20 | Mtu Motoren- Und Turbinen-Union Munchen Gmbh | Burner for gas turbine engines with axially adjustable swirler |
US5417070A (en) * | 1992-11-24 | 1995-05-23 | Rolls-Royce Plc | Fuel injection apparatus |
DE19627760A1 (en) * | 1996-07-10 | 1998-01-15 | Mtu Muenchen Gmbh | Burner with atomizer nozzle |
US5966937A (en) * | 1997-10-09 | 1999-10-19 | United Technologies Corporation | Radial inlet swirler with twisted vanes for fuel injector |
US6543235B1 (en) * | 2001-08-08 | 2003-04-08 | Cfd Research Corporation | Single-circuit fuel injector for gas turbine combustors |
US20040219466A1 (en) * | 2003-05-02 | 2004-11-04 | Marino John A. | Aggregate dryer burner with compressed air oil atomizer |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2223017A4 (en) * | 2007-11-21 | 2014-01-22 | Woodward Inc | Split-flow pre-filming fuel nozzle |
JP2014137193A (en) * | 2013-01-17 | 2014-07-28 | Hino Motors Ltd | Burner |
FR3057648A1 (en) * | 2016-10-18 | 2018-04-20 | Safran Helicopter Engines | LOW TURBOMACHINE COMBUSTION CHAMBER INJECTION SYSTEM |
Also Published As
Publication number | Publication date |
---|---|
DE102005022772A1 (en) | 2007-01-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP3810491B2 (en) | Air blast spray nozzle | |
US7926282B2 (en) | Pure air blast fuel injector | |
EP3137814B1 (en) | Combustor burner arrangement | |
EP1722164A1 (en) | Fuel injection apparatus | |
US6354072B1 (en) | Methods and apparatus for decreasing combustor emissions | |
EP1632721B1 (en) | Combustor, gas turbine combustor, and air supply method for the same | |
JP5591408B2 (en) | Low calorific value fuel combustor for gas turbines. | |
EP1413830A2 (en) | Piloted airblast fuel injector with modified air splitter | |
US20040112061A1 (en) | Natural gas fuel nozzle for gas turbine engine | |
JPS6161015B2 (en) | ||
EP0800041A2 (en) | Gas turbine engine combustion equipment | |
EP0905443A3 (en) | Dual-fuel nozzle for inhibiting carbon deposition onto combustor surfaces in a gas turbine | |
US6244051B1 (en) | Burner with atomizer nozzle | |
US6112511A (en) | Method and apparatus for water injection via primary jets | |
JPH07217451A (en) | Fuel injector | |
EP1918638A1 (en) | Burner, in particular for a gas turbine | |
CN1265455A (en) | Fuel spraying gun for opraying liquid and/or gas fuel to combustion chamber | |
EP3453973B1 (en) | Fuel spray nozzle | |
Zhao et al. | Experimental investigation on spray characteristics of aircraft kerosene with an external-mixing atomizer | |
US8186165B2 (en) | Turbine fuel nozzle having heat control | |
US11506384B2 (en) | Free-vortex combustor | |
EP3078913A1 (en) | Combustor burner arrangement | |
EP3054211A1 (en) | Atomizer and combustion device using the same | |
JP5193695B2 (en) | Fuel injection device | |
CA1209810A (en) | Turbine combustor having improved secondary nozzle structure for more uniform mixing of fuel and air and improved downstream combustion |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL BA HR MK YU |
|
17P | Request for examination filed |
Effective date: 20070515 |
|
AKX | Designation fees paid |
Designated state(s): DE FR GB IT |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: KARLSRUHER INSTITUT FUER TECHNOLOGIE |
|
17Q | First examination report despatched |
Effective date: 20100806 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20131202 |