Abstract
A method and a device provide a uniform recursive sequential combustion of fuel and oxidizing agents within a thermal system having a continuous flow. Compressed fresh air is directed through the combustion chamber along a primary flow direction. A proportion of the fresh air is supplied to a burner by way of a burner entry and in the burner is combusted with fuel and exits the burner as exhaust gas. The burner is disposed at an angle in relation to the primary flow direction such that part of the exhaust gas exiting the burner exit is imparted a tangential flow in relation to the primary flow direction and circulates in the combustion chamber and enters the burner entry of a downstream burner so as to be mixed with the fresh air flowing into the downstream burner such that a recursive sequential combustion is achieved.
Claims
1-16. (canceled)
17. A method for a uniform recursive sequential combustion of fuel and oxidizing agents within a thermal system having a continuous flow, in a combustion chamber of an engine or a gas turbine, which comprises the steps of: directing compressed fresh air, being the oxidizing agents, through the combustion chamber along a primary flow direction, wherein the fresh air flows in by way of a combustion chamber entry and flows out by way of a combustion chamber exit; supplying a proportion of the fresh air to at least one burner by way of a burner entry and in the at least one burner the fresh air is combusted with the fuel, and exits the at least one burner as exhaust gas at a burner exit; and disposing the at least one burner at an angle in relation to the primary flow direction of a fresh air flow such that part of the exhaust gas exiting the burner exit in the combustion chamber is imparted a tangential flow in relation to the primary flow direction and circulates in the combustion chamber, and enters the burner entry of a downstream burner so as to be mixed with the fresh air flowing into the downstream burner such that a recursive sequential combustion is achieved.
18. The method according to claim 17, wherein the combustion chamber is configured in a form of an inherently closed flow duct in such a manner that a circular flow is configured in the combustion chamber, wherein it is provided that an axis of the combustion chamber is disposed so as to be coaxial with the primary flow direction of a fresh air flow.
19. The method according to claim 17, wherein the combustion chamber has a plurality of sub-segments, wherein each of the sub-segments has in each case one burner, and wherein part of the exhaust gas generated by the burner is in each case directed into an adjacent one of the sub-segments, and a remaining proportion of the exhaust gas is discharged from the combustion chamber by way of the combustion chamber exit.
20. The method according to claim 17, wherein the combustion chamber has a plurality of burners which are disposed so as to be mutually sequential in such a manner that part of the exhaust gas of an upstream first burner of the burners flows in each case into the burner entry of the downstream burner of the burners, wherein the exhaust gas exiting the burner exit of a last burner of the burners flows into the burner entry of the upstream first burner.
21. The method according to claim 17, wherein the at least one burner is configured so as to be helical and has a cross section in a form of a double spiral, wherein the fresh air at the burner entry of the at least one burner is directed in a spiraliform manner into a center of the at least one burner, wherein the fuel is injected by way of injection openings in a region of a center of the at least one burner being a spiraliform burner and is combusted with the fresh air, and wherein the exhaust gas is directed in a spiraliform manner out of the center of the spiraliform burner to the burner exit.
22. The method according to claim 21, wherein a spiral axis of the at least one burner extends at least along part of a cross-sectional axis of the combustion chamber.
23. The method according to claim 17, wherein a ratio between the fresh air entering the at least one burner and the exhaust gas directed into the at least one burner is between 1:1 and 20:1.
24. The method according to claim 17, wherein: the compressed fresh air is compressed by a compressor; and the at least one burner is disposed inclined in relation to the primary flow direction of the fresh air flow.
25. The method according to claim 18, wherein the inherently closed flow duct is a toroidal or annular or loop-shaped flow duct.
26. The method according to claim 17, wherein the sub-segments are circle segments.
27. A device for a uniform recursive sequential combustion of fuel and oxidizing agents within a thermal system having a continuous flow, the device comprising: a combustion chamber having a combustion chamber entry and a combustion chamber exit, wherein compressed fresh air being the oxidizing agents, by way of said combustion chamber entry is able to be conveyed into said combustion chamber, along a primary flow direction of the device through said combustion chamber, and by way of said combustion chamber exit out of said combustion chamber; and said combustion chamber having burners each with at least one injection opening, a burner entry and a burner exit and to which a proportion of the fresh air is able to be supplied by way of said burner entry, wherein the fuel introduced by way of said at least one injection opening is able to be combusted in a respective burner of said burners and as exhaust gas from said respective burner is able to be discharged from said respective burner at said burner exit, said respective burner is disposed at an angle in relation to the primary flow direction of the device such that part of the exhaust gas exiting said burner exit in said combustion chamber is imparted a tangential flow in relation to the primary flow direction and circulates in said combustion chamber, and enters said burner entry of a downstream burner of said burners so as to be mixed with the fresh air flowing into the downstream burner such that a recursive sequential combustion is achieved.
28. The device according to claim 27, wherein said combustion chamber is configured in a form of an inherently closed flow duct in such a manner that a circular flow is configured in said combustion chamber.
29. The device according to claim 27, wherein said combustion chamber has a plurality of sub-segments, wherein each of said sub-segments has in each case one burner of said burners, and wherein said combustion chamber is configured such that part of the exhaust gas generated by said respective burner is in each case able to be directed into an adjacent one of said sub-segments, and a remaining proportion of the exhaust gas is able to be discharged from said combustion chamber by way of said combustion chamber exit.
30. The device according to claim 27, wherein at least two of said burners of said combustion chamber are disposed so as to be mutually sequential in such a manner that part of the exhaust gas of a first upstream burner of said at least two burners flows in each case into said burner entry of a downstream burner of said at least two burners, wherein the exhaust gas exiting the burner exit of a last burner of said at least two burners flows into said burner entry of said first upstream burner.
31. The device according to claim 27, wherein at least one of said burners is configured so as to be helical and has a cross section in a form of a double spiral, wherein said at least one burner is configured to be spiraliform in such a manner that the fresh air, mixed with part of the exhaust gas, at said burner entry of said at least one burner is able to be directed in a spiraliform manner into a center of said at least one burner, wherein the fuel is able to be injected by way of injection openings in a region of said center of said at least one burner being a spiraliform burner and is able to be combusted with the fresh air, and wherein the exhaust gas is able to be directed in a spiraliform manner out of said center of said spiraliform burner to said burner exit.
32. The device according to claim 31, wherein a spiral axis of said at least one burner extends at least along part of a cross-sectional axis of said combustion chamber.
33. The device according to claim 27, wherein at least one of said burners is configured as a swirl generator, turbulence generator or cyclone.
34. An engine, comprising: a device according to claim 27.
35. A gas turbine, comprising: a device according to claim 27.
Description
[0027] FIG. 1 shows a first embodiment of the device according to the invention in a schematic view;
[0028] FIG. 2 shows a simplified embodiment of a burner assembly according to FIG. 1;
[0029] FIG. 3 shows a second embodiment of a device according to the invention in a schematic illustration;
[0030] FIG. 4 shows a schematic view having a plurality of sub-segments according to;
[0031] FIG. 5 shows a schematic view of a sub-segment of the combustion chamber of FIG. 4;
[0032] FIG. 6 shows an embodiment of the burner as a double spiral;
[0033] FIG. 7 shows a schematic illustration of the flow states within the burner configured as a double spiral;
[0034] FIG. 8 shows a preferred embodiment of the combustion chamber as a double spiral;
[0035] FIGS. 9 to 12 show embodiments of the device according to the invention with different configurations of the sub-segments;
[0036] FIG. 13 shows a schematic view of the circular flow with different sub-segments;
[0037] FIG. 14 shows a further embodiment of potential sub-segments;
[0038] FIGS. 15 to 17 show an embodiment of the combustion chamber having three burners; and
[0039] FIG. 18 shows an exemplary embodiment of a burner according to the invention which is configured as a cyclone, or a mixing chamber of a burner, which is configured as a swirl generator in the form of a cyclone;
[0040] FIG. 19 shows a view from above onto the cyclone from FIG. 18;
[0041] FIG. 20 shows a view of the cyclone from FIG. 19 from below; and
[0042] FIGS. 21-27 show alternative embodiments of the schematic representation of FIGS. 9-14 with a combustion chamber having differently designed sub-segments.
[0043] A first embodiment of the device according to the invention is illustrated in a schematic view in FIG. 1. The device comprises a combustion chamber 1 which is disposed within the device, for example an engine or a gas turbine. Fresh air 6 is directed along a primary flow direction 4 through the device, wherein a proportion of the fresh air 6 flows into the combustion chamber 1 by way of a combustion chamber entry 11. A number of burners 2 are disposed in the combustion chamber 1, in which the fresh air 6 is supplied to the burner 2 by way of a burner entry 21. The fresh air 6 is combusted with fuel in the burner 2. The combusted fuel then exits the burner 2 as exhaust gas 7 at the burner exit 22. The burners 2 here are disposed so as to be inclined at an angle in relation to the primary flow direction 4 of the fresh air flow 6, or of the device, in such a manner that part of the exhaust gas 7 exiting the respective burner exit 22 in the combustion chamber 1 is imparted a tangential flow in relation to the primary flow direction 4 and circulates in the combustion chamber 1. In this manner, the exhaust gases 7 circulating within the combustion chamber 1 are mixed with the inflowing fresh air 6 and directed again into the burner entry 21 of a burner 2, or of the one burner 2. Part of the combusted exhaust gas 7 flows out of the combustion chamber 1 by way of the combustion chamber exit 12 and is supplied to a turbine for further processing, for example. By mixing the exhaust gases 7 exiting the burner exit 22 and the fresh air 6 flowing into the burner 2, and by re-supplying the fresh air 6 mixed with the exhaust gas 7, a so-called recursive sequential combustion is achieved, in which the formation of oxides of nitrogen is reduced and fine-particulate matter or carbon-particulate matter are further combusted such that a low-emission combustion which is more environmentally friendly is caused.
[0044] FIG. 2 shows a schematic assembly of a plurality of burners 2. The burners 2 in terms of the primary flow direction 4 are inclined at an angle in relation to the latter such that the exhaust gas 7 flowing out of the upstream burner 21 in each case enters the burner entry 212 of the second burner 22, is again mixed with fresh air 6 in the latter, and is further combusted. The exhaust gas 7 exiting the second burner 22 is again partially supplied to the downstream burner 23 of the latter and therein, mixed with fresh air 6, combusted again. The embodiment illustrated in FIG. 2 causes a partial overlap of the burner exit 22.sub.n of a respective burner 2.sub.n with the burner entry 21.sub.n+1 of the downstream burner 2.sub.n+1, such that part of the exhaust gas 7 is in each case supplied to the downstream burner 2.sub.n+1. Furthermore, a circular flow of the exhaust gases 7 within the combustion chamber 1 is achieved as a result of this assembly, such that said exhaust gases 7 can simply be supplied to the downstream burners 2.sub.n+1, or supplied to recursive combustion again.
[0045] FIG. 3 shows a further embodiment of the device according to the invention in a schematic view. The burners 2 are in each case inclined at an angle in relation to the primary flow direction 4, or disposed at an angle, such that part of the exhaust gases within the combustion chamber 1 are imparted a tangential flow and supplied to the respective downstream burners 2, so as to in this manner again achieve a recursive sequential combustion. The combustion chamber 1 in the embodiments illustrated in FIGS. 1 to 3 is configured as a flow duct, whereby the term flow duct is not to be understood as limiting but only as to mean that part of the exhaust gas 7 can circulate within the combustion chamber 1 as a result of the configuration of the combustion chamber 1, or of the combustion chamber 1 configured as a flow duct. This can be achieved, for example as illustrated in FIG. 2, by a fixed flow duct which is delimited by walls or, as illustrated in FIG. 3, by baffles or guide vanes, for example, which deflect the flow of exhaust gas and force the latter to perform a circulating flow.
[0046] A further embodiment of the device according to the invention is illustrated in a schematic view in FIGS. 4 and 5. The combustion chamber 1 is configured as a toroidal, inherently closed flow duct. The axis of the toroidal combustion chamber 1 lies so as to be coaxial with the primary flow direction 4 of the fresh air flow 6 within the device, such that the combustion chamber 1 is disposed in the primary flow direction 4 of the fresh air flow 6 within the device. The combustion chamber 1 has a number of sub-segments 5, four sub-segments 5 in the embodiment illustrated in FIG. 5, which are disposed next to one another in the direction of the primary flow direction 4. FIG. 5 shows the toroidal combustion chamber 1 in the developed form so that the four sub-segments 5 are depicted in a two-dimensional manner. FIG. 4 shows the fresh air flow 6 which enters the combustion chamber 1 by way of the combustion chamber entry 11 and enters a sub-segment 5. Disposed in the sub-segments 5 of the combustion chamber 1 is a burner 2, not illustrated, in which the fresh air 6 is combusted with fuel such that exhaust gas 7 exits the burner 2. As a result of the toroidal configuration of the combustion chamber 1, and of the disposal of the burners 2 at an angle in relation to the primary flow direction of the fresh air flow 6, or of the device, the exhaust gas 7 is circulated within the combustion chamber 1 such that part of the exhaust gas 7 is in each case directed to the downstream sub-segment 5, and in the latter with a burner 2 is again combusted with the fresh air 6 (FIG. 5) entering the sub-segment 5. Part of the exhaust gases 7 are then moved out of the combustion chamber 1 by way of the combustion chamber exit 12 and supplied to further processing. By mixing the exhaust gases 7 with the fresh air 6, only part of the exhaust gases 7 are in each case circulated within the combustion chamber 1 such that exhaust gases 7 mixed with fresh air 6 can be supplied to the respective further processing in a burner 2.
[0047] As is illustrated in FIGS. 4 and 5, the combustion chamber 1 thus has a plurality of burners 2.sub.n which are disposed so as to be mutually sequential in such a manner that part of the exhaust gas 6 of the upstream burner 2.sub.n flows in each case into the burner entry 21.sub.n+1 of the respective downstream burner 2.sub.n+1. The exhaust gas 7 exiting the last burner 2.sub.n+x in FIG. 5 then enters the burner entry 21.sub.n, in the embodiment illustrated in FIG. 5 the burner entry 211, of the initial or first burner 2.sub.n.
[0048] A preferred embodiment of the burners 2 is illustrated in a schematic view in FIGS. 6 and 7. The burner 2 is configured in the form of a double spiral, wherein the cross section of the burner 2 is of a double-spiral configuration. One spiral runs in the direction of the center 14 of the spiral, and the second from the center 14 of the first spiral outward, so as to be coaxial with the latter. The fresh air 6 enters the burner 2 by way of the burner entry 21 of the latter and in a spiraliform manner runs in the direction of the center 14 of the burner 2. In the center of the burner 2, fuel is introduced into the burner 2 by way of injection openings 9 and combusted with the fresh air 6. The exhaust gas 7 then runs in a spiraliform manner out of the center 14 of the burner 2, and then flows out of the burner 2 and the burner exit 22. As a result of the spiraliform disposal of the burner 2, the fresh air 6 is preheated by the outflowing exhaust gases 6, or the wall of the burner 2 is cooled by the cool inflowing fresh air 6, respectively. As a result of the deflection within the burner 2 of spiraliform configuration, the fresh air 6 entering the burner entry 21 is compressed and accelerated such that a particularly advantageous velocity and pressure profile is configured within the spiraliform structure.
[0049] As is illustrated in FIG. 8, the combustion chamber 1 can be completely configured as a double-spiraliform structure, wherein the fresh air 6 flows in by way of the combustion chamber entry 11, is deflected in a spiraliform manner into the center 14 of the combustion chamber 1, and fuel can be combusted with the fresh air 6 in the center 14 by way of injection openings 9 disposed in a punctiform manner. Part of the exhaust gases 6 then circulate in the center 14 of the spiral and are in this way supplied to a further combustion in each case. Part of the exhaust gases 6, by way of the spiraliform structure of the combustion chamber 1, then flows back in the direction of the combustion chamber exit 12 and therein is delivered for further use in the device.
[0050] As is illustrated in FIGS. 9 to 12, the combustion chamber 1 can be constructed from dissimilar sub-segments 5, wherein one sub-segment 5 may for example have in each case a burner 2 (FIG. 9) of double-spiraliform configuration as described in the context of FIG. 7. The spiral axis of the burner 2, or the cross section of the burner 2, can then extend across part of the cross-sectional axis 8 of the combustion chamber 1 configured as a flow duct, as is illustrated in FIGS. 9 and 11.
[0051] Alternatively, the burner 2 can also be of a banana-shaped configuration and extend along a portion of the sub-segment 5, as is illustrated in FIGS. 10 and 12, such that dissimilar downstream flow angles of the exhaust gas 7 into the dissimilar sub-segments 5 of the burner 2 can be achieved as a result of the distortion of the spiral axis of the burner 2.
[0052] As is illustrated in FIG. 13, the combustion chamber 1 can be formed by a single segment such that the exhaust gas 7 of a single burner 2 is in each case resupplied to the latter, a circular flow of the exhaust gas 7 being able to be achieved by single burner 2 as a result. FIG. 13 furthermore shows the possibility of combining different numbers of sub-segments 5 with one another, wherein one burner 2 can be disposed in each sub-segment 5.
[0053] An optional embodiment of dissimilar burners 2 is illustrated in FIG. 14, wherein the burners 2 in the embodiment illustrated in FIG. 14 have in each case a double-spiraliform cross section and extend along the cross-sectional axis 8 of the toroidal combustion chamber 1 and are disposed behind one another. As is illustrated in FIG. 14, the burners 2 can in each case be directly adjacent to one another such that the burner exit 22.sub.n of a burner 2.sub.n is disposed so as to be congruent with the burner entry 21.sub.n+1 of the downstream burner 2.sub.n+1, or a spacing between the individual burners 2 is in each case provided.
[0054] To that extent, an advantageous embodiment of a combustion chamber 1 with sub-segments is illustrated in FIG. 21-24. The sub-segments 5 and the combustion chamber 1 are produced by 3D printing and have a structure which is particularly light and easy to produce. The support structures 30 of the combustion chamber 1 make it possible to easily produce the structure without requiring much material. Furthermore, the support structures 30 can be adjusted according to the forces occurring in the combustion chamber 1.
[0055] Corresponding to FIGS. 11-14, FIGS. 25-27 show different embodiments of the combustion chamber 1 and the sub-segments 5. The sub-segments 5 can in this case extend in a curved manner or, in different embodiments, along the spiral axis 8 of the combustion chamber 1.
[0056] A further embodiment of the device according to the invention is illustrated in three different views in FIGS. 15 to 17. The combustion chamber 1 is configured as a triangular flow duct, one burner 2 being in each case disposed in the corners of the triangular combustion chamber 1. Fresh air 6 enters the combustion chamber 1 by way of the three combustion chamber entries 11, is supplied to the respective burners 2, and in the latter combusted with fuel. The exhaust gas 7 exiting the respective burners 2 is then circulated along the combustion chamber 1, through the burners 2 which are inclined in relation to the axis of the primary flow direction 4 of the fresh air, and within the combustion chamber 1 configured as a flow duct, such that the exhaust gas 6 is mixed with the fresh air 7 and supplied to the respective downstream burners 2. As a result of the embodiment illustrated in FIGS. 15 to 17, a circular flow of the exhaust gases 7 as is illustrated in FIG. 17 is achieved in a simple manner, such that a recursive sequential combustion of the exhaust gases 7 can take place in a particularly simple manner. Part of the exhaust gases 7 exit the combustion chamber exit 12 such that part of the exhaust gases 7 mixed with the fresh air 6 circulate in each case within the combustion chamber 1.
[0057] Further optimization of the combustion of fuel mixed with oxidizing agents can optionally be achieved in a burner 2 according to the invention, as is illustrated in FIGS. 18 to 20, when the burner 2 is configured as a cyclone. Detailed views of a cyclone of this type, for example for power generation machinery, such as stationary gas turbines or industrial burners, are illustrated in FIGS. 18 to 20.
[0058] Page 5information pertaining to FIG. 18. This form of burner is particularly suitable.
[0059] As can be seen in FIGS. 18 to 20, a burner nozzle 15 having an injection opening 9 is in each case disposed at the inlet of the cyclone, and the air flow 6 or oxidizing agents make its/their way tangentially into the cyclone, this being indicated by the arrows at the inlet of the cyclone. Once the fresh air 6 flows into the cyclone, said fresh air 6 is directed axially out of the cyclone, as can be seen in FIGS. 18 and 20. The burner nozzle 15 is located within this air swirl such that the air swirl entrails the injected fuel droplets. This leads to preliminary mixing of air or oxidizing agents and fuel by swirling, and to air routing or air splitting. The positive mixing of air and fuel droplets prior to entering the combustion chamber leads to an even more uniform combustion in which fewer gas emissions are created. As a result of this embodiment, particularly advantageous, radially introduced mixing between the fresh air, the exhaust gases and the fuel is achieved, and particularly advantageous swirling is caused. Furthermore, a depression is caused by the swirling, which is achieved for suctioning the exhaust gas 7 circulating in the combustion chamber 1 into the burner entry 11.
[0060] As an alternative to the embodiments illustrated in FIGS. 1 to 20, the combustion chamber 1 can also have other configurations, for example be configured so as to be hexagonal, octagonal and also oval, wherein it is only necessary that a circular flow of the exhaust gases 7 mixed with the fresh air 6 is achieved within the combustion chamber 1. Alternatively, the combustion chamber 1 can also be in the form of a ring, in the form of an inherently closed loop, or have cross-sectional shapes other than those shown.
[0061] The device according to the invention illustrated in FIGS. 1 to 20, or the method according to the invention can be used in gas turbines or aircraft engines, for example, wherein the application of the method according to the invention is not limited to these types of application but may also be used in for example other aircraft or helicopter turbines, propeller engines, or other devices in which fuel is combusted.
[0062] A particularly suitable production of the burners shown in FIG. 1 to 20 is achieved by additive manufacturing.
