Axial nozzle and combustion chamber

Abstract

The utility model provides an axial nozzle and a combustion chamber, and relates to the technical field of gas turbines, the axial nozzle comprises a flow guide cover, a fuel pipe, rotational flow blades and fuel spray holes, and the flow guide cover extends in the first direction; at least part of the fuel pipe is installed in an inner cavity of the flow guide cover, the part, located in the inner cavity of the flow guide cover, of the fuel pipe is provided with a first section and a second section which are connected, the fuel pipe is provided with a main fuel channel, and an air flow channel extending in the first direction is formed between the outer circumferential face of the first section and the inner circumferential face of the flow guide cover. The swirl vane is connected between the flow guide cover and the second section and provided with a sub fuel channel and a fuel spray hole which are communicated, the sub fuel channel is communicated with the main fuel channel, the fuel spray hole extends in the second direction, the second direction is perpendicular to the first direction, and the second section, the swirl vane and the flow guide cover jointly form a swirl channel. According to the axial nozzle, the mixing efficiency and uniformity of fuel and air can be improved, the flame stabilizing performance of the axial nozzle is improved, then pollutant emission is reduced, and the working efficiency of the gas turbine is improved.

Description

Technical Field

[0001] The present application relates to the technical field of gas turbines, and particularly relates to an axial nozzle and a combustion chamber. Background Art

[0002] The combustion system of a gas turbine adopts multiple combustion chambers to cooperate to achieve reliable and efficient operation of the gas turbine. Among them, each combustion chamber includes a flame tube, a fuel injection system, and a transition piece that guides the post-combustion hot combustion gas from the flame tube to the turbine.

[0003] In related technologies, in order to improve the working efficiency of a gas turbine, the method of increasing the combustion temperature is generally adopted. However, the increase in the combustion temperature leads to an increase in NOx emissions, and at the same time brings risks of thermoacoustic oscillations and cooling problems in multiple regions; and in order to increase the combustion temperature, it is necessary to superimpose and adopt various combustion technologies such as axial staging to achieve. For example, a fuel injector with a columnar structure as the main body is used as the nozzle for axial staging, but the air-fuel mixing non-uniformity of this structure is relatively high. Summary of the Invention

[0004] The utility model aims to solve at least one of the technical problems in the related technologies to a certain extent.

[0005] To this end, an embodiment of one aspect of the utility model provides an axial nozzle, which can improve the mixing efficiency and uniformity of fuel and air, enhance the flame stabilization performance of the axial nozzle, and thereby reduce pollutant emissions and improve the working efficiency of the gas turbine.

[0006] An embodiment of another aspect of the utility model provides a combustion chamber.

[0007] An axial nozzle according to an embodiment of the utility model includes a fairing, a fuel pipe, and swirl vanes and fuel injection holes.

[0008] Wherein, the fairing extends along a first direction;

[0009] Wherein, at least a part of the fuel pipe is installed in the inner cavity of the fairing. The part of the fuel pipe located in the inner cavity of the fairing has a first section and a second section connected to each other. The fuel pipe is provided with a main fuel passage. An air flow passage extending along the first direction is formed between the outer peripheral surface of the first section and the inner peripheral surface of the fairing;

[0010] In which, the swirl blade is connected between the guide cover and the second section and is provided with a connected sub-fuel channel and a fuel nozzle, the sub-fuel channel is connected to the main fuel channel, the fuel nozzle extends along a second direction, the second direction is perpendicular to the first direction, the second section, the swirl blade and the guide cover together constitute a swirl channel, the swirl channel is connected to the air flow channel along the first direction, and the swirl channel is used to mix air and fuel and transport a mixed medium of the two.

[0011] According to the axial nozzle of the embodiment of the utility model, the air is guided by the guide cover to the air flow channel extending along the first direction, and because the fuel nozzle extends along the second direction, the second direction is perpendicular to the first direction, so that the fuel in the sub-fuel channel can be sprayed along the second direction. At this time, the air and the fuel meet at perpendicular angles in the swirl channel, which enhances the impact between the air and the fuel, and the two are fully mixed. At the same time, the good flow guidance performance of the swirl blade itself also makes the mixed gas rotate itself, and the mixing is more complete. Therefore, compared with the columnar structure fuel injector in the related technology, the axial nozzle of the present application can improve the mixing efficiency and uniformity of fuel and air, thereby improving the flame stabilization performance of the axial nozzle, reducing pollutant emissions, and improving the working efficiency of the gas engine.

[0012] In some embodiments, the swirl blade has two wall surfaces that are opposite to each other along the thickness direction of the swirl blade;

[0013] The fuel injection hole includes a first injection hole and a second injection hole respectively arranged on the two wall surfaces.

[0014] In some embodiments, the first spray holes and the second spray holes are arranged at intervals along the first direction.

[0015] In some embodiments, there are a plurality of the first spray holes and the second spray holes, and the first spray holes are arranged at intervals along a third direction, and the third direction forms an angle with the first direction.

[0016] In some embodiments, there are a plurality of swirl blades which are arranged at intervals along the circumference of the second section of the fuel pipe, the swirl directions of adjacent swirl blades are the same, and a swirl channel is formed between any two adjacent swirl blades and the second section and the guide cover, wherein the first spray hole of one swirl blade and the first spray hole or the second spray hole of another swirl blade are located in the same swirl channel; or

[0017] The rotation directions of adjacent swirl blades are different.

[0018] In some embodiments, the sub-fuel channel extends from a wall surface of the swirl blade away from the second section toward the main fuel channel along the third direction, and a cross-sectional profile of the sub-fuel channel is circular.

[0019] In some embodiments, the axial nozzle further includes a fuel flange which is installed on a portion of the fuel pipe away from the first section. The fuel flange communicates with the main fuel passage and is used to connect to a fuel source.

[0020] In some embodiments, the fairing includes a first fairing section, a second fairing section and a connecting flange which are connected in sequence along the first direction. The inner diameter of the first fairing section gradually decreases along the first direction. The inner diameter of the second fairing section is equal to the minimum inner diameter of the first fairing section and is smoothly connected to the minimum inner diameter end of the first fairing section. The connecting flange is connected to the combustion chamber;

[0021] At least a part of the first section of the fuel pipe is located in the inner cavity of the first fairing section;

[0022] The swirl vanes are installed in the inner cavity of the second fairing section.

[0023] In some embodiments, the inner wall surfaces of the first fairing section and the second fairing section are both smooth curved surfaces.

[0024] A combustion chamber according to an embodiment of the present invention includes the axial nozzle as described above.

[0025] The technical advantages of the combustion chamber according to the embodiment of the present invention are the same as those of the above axial nozzle, and will not be elaborated here.

[0026] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a three-dimensional structural schematic diagram of an axial nozzle according to an embodiment of the present invention.

[0028] Figure 2 is a cross-sectional structural schematic diagram of an axial nozzle according to an embodiment of the present invention.

[0029] Figure 3 is a connection structural schematic diagram of a fuel pipe and swirl vanes in an axial nozzle according to an embodiment of the present invention.

[0030] Figure 4 is a flow path schematic diagram of fuel and air in an axial nozzle according to an embodiment of the present invention.

[0031] Reference numerals: 1. Fairing, 11. First fairing section, 12. Second fairing section, 13. Connecting flange, 2. Fuel pipe, 21. First section, 22. Second section, 23. Main fuel passage, 3. Swirl vane, 31. Sub-fuel passage, 4. Fuel injection hole, 41. First injection hole, 42. Second injection hole, 5. Fuel flange. Detailed implementation mode

[0032] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as a limitation to the present invention.

[0033] As Figure 1 and Figure 2 shown, an axial nozzle according to an embodiment of the present invention includes a fairing 1, a fuel pipe 2, a swirl vane 3, and a fuel injection hole 4.

[0034] Among them, the fairing 1 extends in the first direction.

[0035] Among them, at least a part of the fuel pipe 2 is installed in the inner cavity of the fairing 1. The part of the fuel pipe 2 located in the inner cavity of the fairing 1 has a connected first section 21 and a second section 22. The fuel pipe 2 is provided with a main fuel passage 23. An air flow passage extending in the first direction is formed between the outer peripheral surface of the first section 21 and the inner peripheral surface of the fairing 1.

[0036] Among them, the swirl vane 3 is connected between the fairing 1 and the second section 22 and is provided with a connected sub-fuel passage 31 and a fuel injection hole 4. The sub-fuel passage 31 is connected to the main fuel passage 23. The fuel injection hole 4 extends in the second direction, and the second direction is perpendicular to the first direction. The second section 22, the swirl vane 3, and the fairing 1 together form a swirl passage. The swirl passage is connected to the air flow passage in the first direction. The swirl passage is used to mix air and fuel and transport the mixed medium of the two.

[0037] According to the axial nozzle of the embodiment of the present invention, the fairing 1 guides air into the air flow passage extending in the first direction. Since the fuel injection hole 4 extends in the second direction and the second direction is perpendicular to the first direction, the fuel in the sub-fuel passage 31 can be ejected along the second direction. At this time, the air and the fuel meet at a perpendicular angle in the swirl passage, enhancing the impact between the air and the fuel, and the two are fully mixed. At the same time, the good flow guiding performance of the swirl vane 3 itself also makes the mixed gas rotate by itself, and the mixing is more sufficient. Therefore, compared with the columnar fuel injector in the related art, the axial nozzle of the present application can improve the mixing efficiency and uniformity of fuel and air, thereby improving the flame stabilization performance of the axial nozzle, reducing pollutant emissions, and improving the working efficiency of the gas turbine.

[0038] Specifically, the air in the air deflector 1 is the flowing air in the combustion cylinder, the inner cavity of the fuel pipe 2 can be the main fuel channel 23, the inner part of the swirl blade 3 can form a sub-fuel channel 31, and the fuel injection hole 4 can be opened on the swirl blade 3.

[0039] It should be noted that the specific structure of the swirl blade 3 can adopt the existing technology in the field. The swirl blade 3 itself has a curved curvature, so it can guide the gas passing through the outer surface of the blade to change the flow direction according to the shape of the outer surface of the blade, so that the gas after the fuel and air are mixed in this application with a rotation trend similar to the curvature of the blade (the mixed gas originally flows along the first direction, and through the guidance of the blade, the gas not only flows along the first direction but also has a spiral trend along the outer surface of the blade) Enter the flame tube to participate in combustion. This rotation trend enhances the impact force of the mixed gas and makes it closer to the central combustion area of ​​the flame tube, thereby further ensuring the full combustion of the fuel.

[0040] like Figure 2 and Figure 3 As shown, in some embodiments, the swirl blade 3 has two wall surfaces opposite to each other along the thickness direction of the swirl blade 3 .

[0041] The fuel injection hole 4 includes a first injection hole 41 and a second injection hole 42 which are respectively arranged on two wall surfaces.

[0042] By respectively arranging the first nozzle 41 and the second nozzle 42 on the two walls of the fuel nozzle 4, fuel can be sprayed out on both sides of the swirl blade 3. Compared with spraying fuel only from one side of the swirl blade 3, this method can ensure the consistency of the fuel and air mixture in the mixed gas at various locations in the swirl channel.

[0043] Specifically, the first spray hole 41 and the second spray hole 42 are opened on the wall surface of the swirl blade 3 .

[0044] like Figure 2 and Figure 3 As shown, in some embodiments, the first spray holes 41 and the second spray holes 42 are arranged at intervals along the first direction.

[0045] The first spray hole 41 and the second spray hole 42 are arranged in a first direction at intervals, so that there is a distance between their spraying positions in the swirl channel. The fuel in the same sub-fuel channel 31 is sprayed in two ways, further ensuring sufficient mixing of fuel and air.

[0046] Specifically, there is a gap between the axes of the projections of the first spray hole 41 and the second spray hole 42 on the same plane along the first direction.

[0047] like Figure 2 and Figure 3As shown, in some embodiments, there are multiple first spray holes 41 and multiple second spray holes 42, which are arranged at intervals along a third direction, and the third direction forms an angle with the first direction.

[0048] Specifically, the number of the first spray holes 41 and the second spray holes 42 may be the same or different. To ensure sufficient mixing of fuel and air, the first spray holes 41 may be arranged on a part of the swirl vane 3 closer to the first section 21 of the fuel pipe 2 than the second spray holes 42, and at the same time, the number of the first spray holes 41 is less than the number of the second spray holes 42.

[0049] Preferably, to further simplify the processing difficulty, there are multiple first spray holes 41 and multiple second spray holes 42, which are arranged at intervals along a third direction, and the third direction is perpendicular to the first direction.

[0050] As Figures 1 to 3 shown, in some embodiments, there are multiple swirl vanes 3, which are arranged at intervals along the circumferential direction of the second section 22 of the fuel pipe 2. The swirl directions of adjacent swirl vanes 3 are the same. An arbitrary adjacent two swirl vanes 3 and the second section 22 and the flow guide cover 1 form a swirl channel. The first spray holes 41 of one swirl vane 3 and the first spray holes 41 or the second spray holes 42 of another swirl vane 3 are located in the same swirl channel.

[0051] Alternatively, the swirl directions of adjacent swirl vanes 3 are different.

[0052] Preferably, to ensure sufficient and uniform mixing of fuel and air, there are multiple swirl vanes 3, which are arranged at intervals along the circumferential direction of the second section 22 of the fuel pipe 2. The swirl directions of adjacent swirl vanes 3 are the same. An arbitrary adjacent two swirl vanes 3 and the second section 22 and the flow guide cover 1 form a swirl channel. The first spray holes 41 of one swirl vane 3 and the second spray holes 42 of another swirl vane 3 are located in the same swirl channel.

[0053] As Figure 3 shown, in some embodiments, the sub-fuel channel 31 extends along the third direction from the wall surface of the swirl vane 3 facing away from the second section 22 towards the main fuel channel 23, and the cross-sectional profile of the sub-fuel channel 31 is circular.

[0054] Adopting the design that the cross-sectional profile of the sub-fuel channel 31 is circular not only retains the characteristics of easy processing and smooth channel of the circle, but also can, on the premise of ensuring the thickness of the swirl vane 3 itself, increase the volume of the sub-fuel channel 31 as much as possible to reduce the fuel flow rate, thereby reducing the pressure loss (Bernoulli equation, high flow rate means low pressure, low flow rate means high pressure. In this application, to ensure the impact force of the mixed gas formed by fuel and air supplied to the combustion chamber, it is necessary to make the fuel have high pressure, so it can be achieved by reducing the fuel gas flow rate). In addition, the flow rates between the spray holes in the multiple first spray holes 41 and the multiple second spray holes 42 are more uniform.

[0055] Specifically, two sub-fuel channels 31 are formed on each swirl vane 3. One of the sub-fuel channels 31 communicates with the first injection hole 41, and the other sub-fuel channel 31 communicates with the second injection hole 42. For the convenience of machining the sub-fuel channels 31, it can be selected to penetrate the wall surface of the second section 22 of the swirl vane 3 away from the fuel pipe 2 to open the sub-fuel channels 31 until they communicate with the main fuel channel 23.

[0056] Preferably, the sub-fuel channels 31 extend through the wall surface of the second section 22 of the swirl vane 3 away from the fuel pipe 2 in a third direction perpendicular to the first direction towards the main fuel channel 23.

[0057] As Figure 1 and Figure 2 shown, in some embodiments, the axial nozzle further includes a fuel flange 5. The fuel flange 5 is installed on the part of the fuel pipe 2 away from the first section 21. The fuel flange 5 communicates with the main fuel channel 23 and is used to connect with a fuel source.

[0058] Specifically, the fuel flange 5 can be connected to the fuel source through a pipeline.

[0059] As Figure 1 and Figure 4 shown, in some embodiments, the fairing 1 includes a first fairing section 11, a second fairing section 12 and a connecting flange 13 connected in sequence along the first direction. The inner diameter of the first fairing section 11 gradually decreases along the first direction. The inner diameter of the second fairing section 12 is equal to the minimum inner diameter of the first fairing section 11 and is smoothly connected to the minimum inner diameter end of the first fairing section 11. The connecting flange 13 is connected to the combustion chamber.

[0060] At least part of the first section 21 of the fuel pipe 2 is located in the inner cavity of the first fairing section 11.

[0061] The swirl vanes 3 are installed in the inner cavity of the second fairing section 12.

[0062] The fairing 1 can guide the air supplied to the axial nozzle to ensure that the air flow direction can be perpendicular to the direction of the fuel ejected from the fuel injection holes 4.

[0063] Specifically, the connecting flange 13 can be fixed to the combustion chamber by bolts. The inner profiles of the cross-sections of the first fairing section 11, the second fairing section 12 and the connecting flange 13 can all be circular. An air flow channel is formed between the outer peripheral surface of the first section 21 and the inner peripheral surface of the first fairing section 11. The inner peripheral surfaces of the second section 22, the swirl vanes 3 and the second fairing section 12 together form a swirl channel.

[0064] As Figure 1 shown, in some embodiments, the inner wall surfaces of the first fairing section 11 and the second fairing section 12 are both smooth curved surfaces.

[0065] The inner wall surfaces of the first flow guiding section 11 and the second flow guiding section 12 are designed as smooth curved surfaces, which not only ensure the consistency of the air flow direction but also reduce the pressure loss during the air flow process.

[0066] As Figures 1 to 4 shown, a combustion chamber according to an embodiment of the present invention includes the axial nozzle as described above.

[0067] The technical advantages of the combustion chamber according to the embodiment of the present invention are the same as those of the above axial nozzle, and will not be elaborated here.

[0068] Now, in combination with the specific structure of the axial nozzle, its working process will be described in detail as follows: The combustion pressure cylinder supplies air to the axial nozzle, so that the air enters the swirl passage along the air flow passage. During this process, the fuel source supplies fuel to the main fuel passage 23 through a pipeline. The fuel enters the sub-fuel passage 31 from the main fuel passage 23 and is divided into two paths and ejected by the first spray hole 41 and the second spray hole 42. At this time, the fuel meets and fully mixes with the air perpendicular to the air flow direction in the swirl passage. Finally, the mixed gas enters the flame tube to participate in combustion with a rotation trend similar to the radian of the swirl vane 3.

[0069] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0070] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0071] In the present utility model, unless otherwise clearly specified or limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or capable of communicating with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0072] In the present utility model, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0073] In the present utility model, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0074] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. An axial nozzle, characterized in that: include: A flow guide cover extending along a first direction; a fuel pipe, wherein at least a portion of the fuel pipe is installed in the inner cavity of the air deflector, the portion of the fuel pipe located in the inner cavity of the air deflector comprises a first section and a second section connected to each other, the fuel pipe is provided with a main fuel passage, and an air flow passage extending along the first direction is formed between an outer circumferential surface of the first section and an inner circumferential surface of the air deflector; and A swirl blade and a fuel nozzle, wherein the swirl blade is connected between the guide cover and the second section and is provided with a connected sub-fuel channel and a fuel nozzle, the sub-fuel channel is connected to the main fuel channel, the fuel nozzle extends along a second direction, the second direction is perpendicular to the first direction, the second section, the swirl blade and the guide cover together constitute a swirl channel, the swirl channel is connected to the air flow channel along the first direction, and the swirl channel is used to mix air and fuel and transport a mixed medium of the two.

2. The axial nozzle according to claim 1, characterized in that The swirl blade has two wall surfaces opposite to each other along the thickness direction of the swirl blade; The fuel injection hole includes a first injection hole and a second injection hole respectively arranged on the two wall surfaces.

3. The axial nozzle according to claim 2, characterized in that The first spray holes and the second spray holes are arranged at intervals along the first direction.

4. The axial nozzle according to claim 2 or 3, characterized in that There are a plurality of the first spray holes and the second spray holes, which are arranged at intervals along a third direction, and the third direction forms an angle with the first direction.

5. The axial nozzle according to claim 2 or 3, characterized in that There are a plurality of swirl blades arranged at intervals along the circumference of the second section of the fuel pipe, the swirl directions of adjacent swirl blades are the same, and a swirl channel is formed between any two adjacent swirl blades and the second section and the guide cover, wherein the first spray hole of one swirl blade and the first spray hole or the second spray hole of another swirl blade are located in the same swirl channel; or The rotation directions of adjacent swirl blades are different.

6. The axial nozzle according to claim 4, characterized in that The sub-fuel channel extends from the wall of the swirl blade away from the second section along the third direction toward the main fuel channel, and the cross-sectional profile of the sub-fuel channel is circular.

7. The axial nozzle according to claim 1, characterized in that The axial nozzle further includes a fuel flange mounted on a portion of the fuel pipe away from the first section, the fuel flange being in communication with the main fuel passage and configured to be connected to a fuel source.

8. The axial nozzle according to claim 1, characterized in that The deflector comprises a first deflector section, a second deflector section and a connecting flange which are sequentially connected along the first direction, the inner diameter of the first deflector section gradually decreases along the first direction, the inner diameter of the second deflector section is equal to the minimum inner diameter of the first deflector section and is smoothly connected to the minimum inner diameter end of the first deflector section, and the connecting flange is connected to the combustion chamber; At least a portion of the first section of the fuel pipe is located in the inner cavity of the first flow guide section; The swirl blades are installed in the inner cavity of the second guide section.

9. The axial nozzle according to claim 8, characterized in that The inner wall surfaces of the first guide section and the second guide section are both smooth curved surfaces.

10. A combustion chamber, characterized in that: The combustion chamber comprises the axial nozzle according to any one of claims 1-9.

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