Nozzle device for feeding fuel into a combustion chamber of a gas turbine assembly, and gas turbine assembly

Abstract

A nozzle device for feeding fuel into a combustion chamber of a gas turbine assembly, includes: a nozzle main body having nozzle openings for injecting the fuel into the combustion chamber; a nozzle bracket having a fuel line for fluidic connection between a manifold fuel line and the main body, wherein at least a portion of the fuel line is aligned along, a central longitudinal axis; and a throttle element disposed downstream of the manifold fuel line for throttling the fuel flow to a pre-specified target quantity. The throttle element includes two stages which are fluidically disposed in series, each stage having a line portion aligned along a central longitudinal axis and a flow cross section. A relaxation chamber is disposed between the stages, the flow cross section of the relaxation chamber being larger than the flow cross section of the upstream stage.

Claims

1. A nozzle device for feeding gaseous fuel into a combustion chamber of a gas turbine assembly, comprising: a nozzle main body having nozzle openings for injecting the gaseous fuel into the combustion chamber; a nozzle bracket including a fuel line for the fluidic connection between a manifold fuel line of a gaseous fuel manifold and the nozzle main body, wherein the fuel line at least in portions is aligned along, to be symmetrical to, a central longitudinal axis of the nozzle bracket; and a throttle element, which is disposed downstream of the manifold fuel line, on an the upstream end of the fuel line, for throttling a fuel flow to a pre-specified target quantity, wherein the throttle element comprises: at least two stages which are fluidically disposed in series, wherein each of the two stages includes a line portion which is aligned along a respective line portion longitudinal axis and has a flow cross section, wherein each line portion has a single entrance and a single exit, wherein the respective line portion longitudinal axes of the respective line portions of the at least two stages are radially offset from one another, and a relaxation chamber disposed between the at least two stages, a flow cross section of said relaxation chamber being larger than the flow cross section of the one of the two stages disposed upstream of the relaxation chamber, wherein an open space of the relaxation chamber at least partially overlaps the central longitudinal axis of the nozzle bracket.

2. The nozzle device according to claim 1, wherein at least one of the line portions within the throttle element has a smaller flow cross section than the manifold fuel line and/or the fuel line downstream of the throttle element.

3. The nozzle device according to claim 1, wherein the line portion has a circular flow cross section with a diameter, wherein a first stage of the at least two stages, disposed farthest upstream, has a flow cross section larger than others of the at least two stages.

4. The nozzle device according to claim 1, wherein any of the at least two stages fluidically disposed downstream of one of the at least two stages has a same or a smaller flow cross section than the one of the at least two stages.

5. The nozzle device according to claim 1, wherein the respective line portions are disposed to be at least in part mutually coaxial and/or coaxial with the central longitudinal axis.

6. The nozzle device according to claim 1, wherein the line portion longitudinal axis of at least one of the at least two stages is radially offset from the central longitudinal axis downstream of the throttle element.

7. The nozzle device according to claim 6, wherein the radial offset is disposed such that the line portion longitudinal axes are mutually offset by between 90? and 270? in a revolving direction.

8. The nozzle device according to claim 6, wherein the radial offset is configured such that the flow cross sections of the line portions of at least two successive stages in terms of the radial position thereof and/or the position thereof in the revolving direction, have a small overlap, of at most 20% of the flow cross section, or no overlap.

9. The nozzle device according to claim 1, wherein the line portion longitudinal axis of at least one of the at least two stages is disposed so as to be inclined at an angle in relation to the line portion longitudinal axis of another of the at least two stages and/or to the central longitudinal axis downstream of the throttle element.

10. The nozzle device according to claim 9, wherein a plurality of line portion longitudinal axes disposed in succession are disposed to be inclined at the angle in relation to the central longitudinal axis downstream of the throttle element, wherein the respective inclinations alternate in a revolving direction.

11. The nozzle device according to claim 1, wherein the throttle element comprises a cylindrical, monolithic, hollow body, the hollow body being fastened to or in the nozzle bracket while being sealed in a fluid-tight manner.

12. The nozzle device according to claim 1, wherein the throttle element, comprises at least two individual elements or is formed therefrom, wherein each of the two individual elements comprises the line portion of one of the at least two stages.

13. The nozzle device according to claim 1, and further comprising a plurality of the relaxation chambers, wherein the respective flow cross sections thereof, are of identical configuration.

14. The nozzle device according to claim 13, wherein the respective flow cross sections of the relaxation chambers correspond to the flow cross section of the fuel line disposed downstream of the throttle element.

15. A gas turbine assembly having a turbine assembly having at least one of the nozzle device according to claim 1.

16. The nozzle device according to claim 1, wherein the relaxation chamber has a relaxation chamber longitudinal axis that is coaxial with the central longitudinal axis.

17. The nozzle device according to claim 16, wherein an axial length of at least one of the line portions is smaller than a diameter of the at least one of the line portions.

18. The nozzle device according to claim 1, wherein an axial length of at least one of the line portions is smaller than a diameter of the at least one of the line portions.

19. The nozzle device according to claim 1, wherein the respective line portion longitudinal axes of the respective line portions of the at least two stages are parallel to one another.

20. The nozzle device according to claim 1, wherein the line portion longitudinal axis of both of the at least two stages are radially offset from the central longitudinal axis downstream of the throttle element.

Description

(1) The invention will be explained in more detail hereunder by means of exemplary embodiments with reference to the drawings, in which:

(2) FIG. 1 shows a nozzle device having a throttle element for throttling a fuel flow to a pre-specified target quantity according to the invention, in a schematic longitudinal sectional illustration;

(3) FIG. 2 shows a proposed nozzle device having the throttle element comprising three stages which in the flow direction have a successively smaller diameter, in a schematic longitudinal sectional illustration;

(4) FIG. 3 shows a further variant of configuration of the proposed nozzle device having the throttle element comprising three stages of identical diameter, in a schematic longitudinal sectional illustration;

(5) FIG. 4 shows a further variant of configuration of the proposed nozzle device having the throttle element comprising two stages which in the flow direction have a successively smaller diameter, in a schematic longitudinal sectional illustration;

(6) FIG. 5 shows a further variant of configuration of the proposed nozzle device having the throttle element comprising three individual elements and three stages in a schematic longitudinal sectional illustration;

(7) FIG. 6 shows a further variant of configuration of the proposed nozzle device having the throttle element comprising three stages with radially offset line portions, in a schematic longitudinal sectional illustration;

(8) FIG. 7 shows a further variant of configuration of the proposed nozzle device having the throttle element comprising three stages with inclined line portions, in a schematic longitudinal sectional illustration; and

(9) FIGS. 8A, B, C each show exemplary shapes of flow cross sections of two in particular successive line portions, in a schematic illustration viewed from above.

(10) FIG. 1 in a schematic longitudinal sectional illustration shows a nozzle device 1 for feeding fuel 14 into a combustion chamber of a gas turbine assembly, in particular of the engine of an aircraft. The nozzle device 1 has a nozzle main body 1a which is indicated in FIG. 1 and by way of which fuel 14 is injected into the combustion chamber by means of nozzle openings (not shown in FIG. 1) during operation.

(11) The nozzle device 1 shown in FIG. 1 is in particular configured for feeding liquid fuels, e.g. kerosene.

(12) The nozzle device 1 furthermore has a nozzle bracket 1b, here by way of example having one fuel line 2. In the installed state the fuel line 2 forms a fluidic connection between a port 4 of a fuel manifold, having a fuel supply line 3, and the nozzle main body 1a. The fuel line 2, at least in portions, is aligned along a central longitudinal axis M, wherein the central longitudinal axis M forms the axis of symmetry. The fuel line 2, at least in a portion disposed downstream of a throttle element 7, has in particular a circular flow cross section having a diameter Ds which is delimited by a wall 20 of the fuel line 2.

(13) FIG. 1 shows the port 4 having the fuel supply line 3. The fuel line 3, at least directly upstream of the fuel line 2, has in particular a circular flow cross section having a diameter Dm, wherein the flow cross section of the fuel supply line 3 is larger than the flow cross section of the fuel line 2. In the case of the preferably circular configuration of the flow cross section, the following thus applies: Dm>Ds.

(14) The fuel supply line 3 and the nozzle bracket 1b are connected to one another in a fluid-tight manner by a connection assembly 5. The connection assembly 5 can be configured, for example, as a screw connection having a nut and a corresponding thread.

(15) The throttle element 7 is disposed on the upstream (entry-proximal) end of the fuel line 2, which throttle element 7 during operation throttles the fuel flow (volumetric flow) flowing from the fuel supply line 3 into the nozzle device 1 to a pre-specified target quantity required for operating the combustion chamber.

(16) By way of example, the throttle element 7 here is configured as a cylindrical hollow body 70 which is inserted, in particular in a form-fitting manner, into a corresponding cylindrical recess 15 in the wall 20. Another configuration, e.g. a disposal between the port 4 and the nozzle bracket 1b, would also be possible.

(17) By way of example, an encircling annular seal 13 is present as a sealing means for sealing in a fluid-tight manner on the external side of the annular body 70. The upstream end of the hollow body 70 terminates so as to be substantially flush with the face of the upstream end of the wall 20. A wall of the fuel supply line 3 radially overlaps the hollow body 70 for axial fixing.

(18) The hollow body 70 comprises a line portion 6 of the fuel line 2 which is disposed within the throttle element 7 and which is in particular formed by a central, longitudinally aligned bore 60 running in the longitudinal direction through the hollow body 70. The bore 6 by way of a central longitudinal axis M1 is disposed so as to be coaxial with the portion of the fuel line 2 disposed downstream of the throttle element 7, wherein the central longitudinal axis M1 lies on the central axis M.

(19) The line portion 6 of the throttle element 7 has a flow cross section that is smaller than the portion of the fuel line 2 disposed downstream of the throttle element 7. The flow cross section is preferably configured so as to be circular and has a diameter Do. In the case of the preferably circular configuration also of the other flow cross sections, Dm>Ds>Do thus applies. This reflects in an exemplary manner the correlation between the diameters of the flow cross sections. In the case of a non-circular configuration of the flow cross sections, the relative correlations of the respective portions apply generally to the respective flow cross sections (also in terms of the exemplary embodiments according to FIGS. 2 to 8).

(20) During operation, fuel 14 flows into the nozzle device 1 by way of the port 4. In the process, the fuel flow first passes the throttle element 7 in which, owing to the reduction of the flow cross section, a pressure drop resulting in a flow resistance is generated in such a manner that the target quantity of fuel 14 is supplied to the nozzle main body 1a through the fuel line 2.

(21) In the case of fuels of low density (gaseous fuels such as methane and/or hydrogen), disadvantageously high velocities of several hundred metres per second can arise for adjusting the required pressure drop.

(22) In order for this to be avoided, a nozzle device 1 having a modified throttle element 7 is proposed for fuels of low density, in particular hydrogen. A variant of embodiment of the modified throttle element 7 is shown in FIG. 2.

(23) The throttle element 7 shown in FIG. 2 has at least two, by way of example in FIG. 2 three, stages S1, S2, S3 which are fluidically disposed in series. Each stage S1, S2, S3 has a line portion 8, 9, 10 of the fuel line 2 which is disposed along a respective central longitudinal axis M1, M2, M3 and has a respective, in particular constant, flow cross section. For example, the line portions 8, 9, 10 are in each case formed by an in particular cylindrical bore 80, 90, 100. The flow cross sections are in each case preferably configured so as to be circular, having diameters Do1, Do2, Do3.

(24) A relaxation chamber 11 is disposed between the first stage S1 and the second stage S2, the latter being (directly, without any intervening further stage) successive in the flow direction. A relaxation chamber 12 is disposed between the second stage S2 and the third stage S3, the latter being (directly, without any intervening further stage) successive in the flow direction. The relaxation chambers 11, 12 each have a larger flow cross section than the respective stage S1, S2 disposed directly upstream. By way of example, the flow cross sections of the relaxation chamber 11, 12 correspond to one another and/or at least substantially to the flow cross section of the portion of the fuel line 2 downstream of the throttle element 7, wherein the diameter of said flow cross sections approximately equals the diameter Ds.

(25) The axial extent of the relaxation chambers 11, 12 by way of example here is smaller than the axial extent of the line portions 8, 9, 10 in such a manner that a relaxation effect is achieved, the latter however being ideally minor with a view to an ideally compact configuration of the throttle element 7.

(26) The axial extent of the line portions 8, 9, 10 of the individual stages S1, S2, S3 by way of example here is of at least substantially identical configuration. For example, the axial extent is less than the diameter Ds, in particular less than half the diameter Ds.

(27) The throttle element 7 which comprises the stages S1, S2, S3 and the relaxation chambers 11, 12, by way of example in FIG. 2 is integrally manufactured, i.e. is monolithic. The production can take place, for example, by means of an additive manufacturing method (3D-printing).

(28) By way of example, the line portions 8, 9, 10 in FIG. 2 are disposed so as to be coaxial with the portion of the fuel line 2 downstream of the throttle element 7, whereby the respective central longitudinal axis M1, M2, M3 of said line portions 8, 9, 10 lies on the central longitudinal axis M.

(29) By way of example, the respective stage S2, S3 disposed downstream in FIG. 2 have a smaller flow cross section than the respective stages S1, S2 disposed directly upstream of the former. Due to the staged arrangement within the throttle element 7, this results in the flow cross section within the fuel line 2 being decreased in steps. In particular, the first stage S1, disposed farthest upstream, has the largest flow cross section having the largest diameter Do1. The subsequent, second stage S2 has a smaller flow cross section having the smaller diameter Do2. The subsequent, third stage S3 has the smallest flow cross section having the smallest diameter Do3. In summary, in the variant of configuration of the nozzle device 1 shown in FIG. 2, this results in a relative mutual correlation of the diameters of the individual lines according to the rule Dm>Ds>Do1>Do2>Do3. In general, with n stages, it applies to ?2: Dm>Ds>Do1> . . . >Don.

(30) FIG. 3 shows a further variant of configuration of the nozzle device 1 having a throttle element 7 comprising three stages S1, S2, S3, In comparison to the variant of configuration shown in FIG. 2, the throttle device 7 according to FIG. 3 differs in that all stages S1, S2, S3 have the same flow cross section, in particular the same diameter Do1, Do2, Do3. Here too, relaxation chambers 11, 12 are disposed between the stages S1, S2, and S2, S3.

(31) In summary, in the variant of configuration of the nozzle device 1 shown in FIG. 3, this results in a relative mutual correlation of the diameters of the individual lines of Dm>Ds>Do1=Do2=Do3. In general, with n stages, it applies to n?2: Dm>Ds>Do1= . . . =Don.

(32) FIG. 4 shows a further variant of configuration of the nozzle device 1 having a throttle element 7, here by way of example comprising two stages S1, S2. The relaxation chamber 11 is disposed between the two stages S1, S2. In terms of the remaining configuration (disposal of the line portions 8, 9; axial extent of the line portions 8, 9 and of the relaxation chamber 11), with the exception of the 2-staged configuration, FIG. 4 corresponds to the variant of configuration shown in FIG. 2, whereby the flow cross section of the first stage S1 is smaller than the flow cross section of the second stage S2, thus: Dm>Ds>Do1>Do2. In the 2-staged configuration, a configuration of the stages S1, S2 according to the rule Dm>Ds>Do1=Do2 would also be possible.

(33) FIG. 5 shows a variant of configuration of the nozzle device 1 having a throttle element 7 which in terms of the configuration and disposal of the line portions 8, 9, 10 and of the relaxation chambers 11, 12 in an exemplary manner corresponds to the variant of configuration shown in FIG. 2. In particular, the diameters of the individual lines are laid out according to the rule Dm>Ds>Do1>Do2>Do3.

(34) As opposed to the variant of configuration shown in FIG. 2, the throttle element 7 has a plurality of individual elements 7a, 7b, 7c, or is presently formed by the individual elements 7a, 7b, 7c, respectively. The individual elements 7a, 7b, 7c are in each case formed from cylindrical hollow bodies which, when assembled, form the hollow body 70. Each individual element 7a, 7b, 7c preferably has the line portion 8, 9, 10 of a stage S1, S2, S3. By way of example, the relaxation chamber 11 is assigned to the individual element 7a having the stage S1. By way of example, the relaxation chamber 12 is assigned to the individual element 7b having the stage S2. A configuration of this type of the throttle element 7 has the particular effect of advantages in the production and/or the installation of the throttle element 7, and/or permits simple modification of the throttle element 7, for example when setting up the nozzle device 1, or the throttle element 7, in the operation on a test bed, respectively.

(35) FIG. 6 shows a further variant of configuration of the nozzle device 1 having a throttle element 7 comprising by way of example three stages S1, S2, S3. In a manner similar to the exemplary embodiment according to FIG. 2, the stages S1, S2, S3 in terms of their flow cross sections are conceived in an exemplary manner according to the rule Dm>Ds>Do1>Do2>Do3.

(36) As opposed to the exemplary embodiment shown in FIG. 2, the line portions 8, 9, 10 by way of their respective central longitudinal axes M1, M2, M3 are disposed so as to be radially offset from the central longitudinal axis M in FIG. 6. The offset of the central longitudinal axes M1, M2, M3 is in each case different for the (directly) successive stages S1, S2, S3, in the present case by way of example so as to be offset in each case in an alternating manner towards the two radially opposite sides of the central longitudinal axis M (e.g. by approximately 180? in the revolving direction). The relaxation chambers 11, 12 are in particular disposed so as to be coaxial with the central longitudinal axis M.

(37) FIG. 7 shows a further variant of configuration of the nozzle device 1 having a throttle element 7 comprising by way of example three stages S1, S2, S3, In a manner similar to the exemplary embodiment according to FIG. 2, the stages S1, S2, S3 in terms of their flow cross sections are conceived in an exemplary manner according to the rule Dm>Ds>Do1>Do2>Do3.

(38) As opposed to the exemplary embodiment shown in FIG. 2, the line portions 8, 9, by way of their respective central longitudinal axes M1, M2, M3 are disposed so as to be inclined at an angle ?1, ?2, ?3 in relation to the central longitudinal axis M, said angle ?1, ?2, ?3 by way of example being constant. The inclines are in each case preferably less than 45?, e.g. less than 30?, in relation to the central longitudinal axis M. The inclines of the central longitudinal axes M1, M2, M3 in terms of their orientations in relation to the revolving direction alternate in each case for the (directly) successive stages S1, S2, S3. By way of example, the central longitudinal axes M1, M2, M3 presently lie in a common plane, but on opposite sides are inclined or aligned, i.e. with an offset of 180? in the revolving direction, relative to the central longitudinal axis M. By way of example, the angles ?1, ?2, ?3 have the same value.

(39) FIG. 8A, FIG. 8B and FIG. 8C in addition to FIG. 6 show in each case in a plan view from above of the line portions 8, 9 of the respective stage S1, S2 exemplary shapes and arrangements which may have offset flow cross sections of two, in particular successive, line portions 8, 9. The offset here is in each case configured in such a manner that the flow cross sections of the line portions 8, 9 of the two successive stages S1, S2 in terms of their radial position and/or position in the revolving direction, here by way of example, do not overlap, i.e. the flow cross sections in sequence in the axial direction have different radial positions and positions in the revolving direction. When viewed in the axial direction, any geometric overlap of successive flow cross sections is thus avoided. This prevents that individual current threads shoot axially through the throttle element 7 without being deflected and thus diminish the throttle effect.

(40) By way of example, the flow cross sections in FIG. 8A are configured so as to be semi-circular and mutually congruent. By way of example, the flow cross sections in FIG. 8B are configured so as to be elliptic and mutually congruent. By way of example, the flow cross sections in FIG. 8C are configured so as to be different, whereby one flow cross section is embodied so as to be circular, and one flow cross section is embodied so as to be crescent-shaped.

(41) The individual features of the exemplary embodiments according to FIG. 2 to FIG. 8 can of course be combined with one another in various ways.

(42) In summary, as a result of the configuration and/or disposal of the stages S1, S2 and optionally S3, in particular of the line portions 8, 9 and optionally 10 in the exemplary embodiments of the throttle element 7 shown in FIG. 2 to FIG. 7, an increased pressure drop per length unit of the throttle element 7 can be achieved without reducing the diameter of the line portions 8, 9 and optionally 10 in such a manner that excessively high velocities arise in the use of gaseous fuels, in particular hydrogen. The flow pattern in particular within the throttle device 7 can be influenced by the different variants of configuration of the nozzle device 1, in particular of the throttle element 7. In this way, a gas turbine assembly can be optimized, in particular with a view to the operation with hydrogen, with the proposed nozzle device 1.

LIST OF REFERENCE SIGNS

(43) 1 Nozzle device 1a Nozzle main body 1b Nozzle bracket 2 Fuel line 20 Wall 3 Fuel supply line 4 Port 5 Connecting means 6 Line portion 60 Bore 7 Throttle element 70 Hollow body 7a Individual element 7b Individual element 7c Individual element 8 Line portion 80 Bore 9 Line portion 90 Bore 10 Line portion 100 Bore 11 Relaxation chamber 12 Relaxation chamber 13 Annular seal 14 Fuel Recess Dm Diameter of manifold fuel line Ds Diameter of fuel line Do Diameter of line portion Do1 Diameter of line portion Do2 Diameter of line portion Do3 Diameter of line portion M Central longitudinal axis M1 Central longitudinal axis M2 Central longitudinal axis M3 Central longitudinal axis S1 Stage S2 Stage S3 Stage ?1 Angle ?2 Angle ?3 Angle