End cover, combustion chamber and gas turbine

Abstract

The end cover comprises an end cover body, the end cover body is provided with a first end face and a second end face which are opposite in the thickness direction of the end cover body, the end cover body is provided with a through hole extending in the thickness direction of the end cover body, and the through hole is provided with a first hole opening and a second hole opening; the first orifice is arranged adjacent to the first end face and used for installing an on-duty nozzle, the second orifice is arranged adjacent to the second end face and used for being communicated with a fuel nozzle, the second end face is provided with an annular blind hole, the annular blind hole is arranged around the through hole and used for being communicated with the fuel nozzle, and the annular blind hole is communicated with the fuel nozzle. The end cover body is further provided with a premixed fuel channel communicated with the annular blind hole. According to the end cover, the requirement for a precious metal alloy brazing material is omitted, the material cost is reduced, the problem of sealing failure caused by low brazing quality is solved, and the stability and durability of equipment are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbines, in particular to an end cover, a combustion chamber and a gas turbine. BACKGROUND

[0002] In the design of conventional gas turbine combustion chambers, in order to achieve isolation of different fuels or air, a sealing insert is usually used to separate the clean blow air flow channel and the premixed stage fuel flow channel. The effective connection of the sealing insert is crucial to ensuring the isolation of air and fuel, because insufficient mixing or leakage will have a negative impact on the performance and safety of the gas turbine.

[0003] In the related art, the sealing insert is usually connected to the end cover by brazing. However, the existing brazing technology has the following problems. First, a noble metal alloy is used as the brazing material, which is relatively expensive. Second, the brazing quality is difficult to detect, and the effectiveness of the seal cannot be ensured. There have been problems of seal failure due to low brazing quality. In addition, the brazing material has reliability problems at high temperatures, and needs to be replaced regularly after a long period of use. SUMMARY

[0004] The present application aims to at least partially solve one of the technical problems in the related art.

[0005] To this end, an embodiment of the present application proposes an end cover, a combustion chamber and a gas turbine.

[0006] The end cover of the embodiment of the present application comprises an end cover body having a first end face and a second end face opposite in the thickness direction thereof, the end cover body being provided with a through hole extending in the thickness direction thereof, the through hole having a first aperture adjacent to the first end face and used for mounting a service nozzle, and a second aperture adjacent to the second end face and used for communicating with a fuel nozzle, the second end face being provided with an annular blind hole surrounding the through hole and used for communicating with the fuel nozzle, the end cover body further being provided with a premixed fuel passage communicating with the annular blind hole, so that the premixed fuel in the premixed fuel passage is delivered to the fuel nozzle through the annular blind hole.

[0007] In some embodiments, the number of the through holes and the annular blind holes is multiple and one-to-one corresponding.

[0008] In some embodiments, the multiple annular blind holes include a first annular hole and a second annular hole arranged at intervals, the premixed fuel passage includes a first-stage premixed fuel passage and a second-stage premixed fuel passage, the premixing ratio of fuel to air in the first-stage premixed fuel passage being lower than that in the second-stage premixed fuel passage, the first-stage premixed fuel passage communicating with the first annular hole, and the second-stage premixed fuel passage communicating with the second annular hole.

[0009] In some embodiments, the first annular hole comprises a large-diameter hole and a small-diameter hole, the inner diameter of the large-diameter hole is larger than that of the small-diameter hole, and the large-diameter hole is arranged adjacent to the second end face relative to the small-diameter hole, and the primary premixed fuel passage communicates with the small-diameter hole.

[0010] In some embodiments, the depth of the first annular hole is greater than that of the second annular hole, the primary premixed fuel passage and the secondary premixed fuel passage are arranged in a direction of thickness of the end cover body, and the primary premixed fuel passage is arranged adjacent to the first end face relative to the secondary premixed fuel passage.

[0011] In some embodiments, the end cover body is provided with a first connecting flow channel, the cross section of the first connecting flow channel is rectangular, the extension direction of the first connecting flow channel intersects the axis of the through hole, and the first connecting flow channel respectively communicates with the small-diameter hole and the primary premixed fuel passage.

[0012] In some embodiments, the end cover body is provided with a second connecting flow channel, the extension direction of the second connecting flow channel is perpendicular to the axis of the through hole, and the second connecting flow channel respectively communicates with the second annular hole and the secondary premixed fuel passage.

[0013] In some embodiments, the annular blind hole has a sealing step surface for placing a sealing ring.

[0014] The combustion chamber of the embodiment of the present application comprises an end cover, a duty nozzle, a fuel nozzle and a sealing ring, the end cover is the end cover described in any of the above embodiments, the duty nozzle is arranged at the first orifice, the fuel nozzle is connected with the end cover, the fuel nozzle communicates with the through hole and the annular blind hole, and the sealing ring is arranged between the second end face and the fuel nozzle.

[0015] The gas turbine of the embodiment of the present application comprises the combustion chamber described in any of the above embodiments.

[0016] The end cover of the embodiment of the present application cancels the sealing insert part, adopts an integral machining mode to form the through hole for conveying air and the annular blind hole for conveying premixed fuel, cancels the need for precious metal alloy brazing material, and reduces the material cost. The cancellation of the sealing connection insert improves the reliability of the seal and avoids the problem of seal failure caused by low brazing quality. Since the reliability problem of the brazing material at high temperature is eliminated, the integral design makes the end cover not need to be replaced regularly during long-term use, improving the stability and durability of the equipment. Since the brazing structure is canceled, the maintenance work is simpler, the frequency and cost of repair and replacement are reduced, and the performance and safety problems caused by leakage or insufficient mixing are also avoided, improving the safety of the gas turbine operation. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a mounting schematic diagram of the end cover of the embodiment of the present application.

[0018] Figure 2 is a structural schematic diagram of the end cover of the first embodiment of the present application.

[0019] Figure 3 is a structural schematic diagram of the end cover of the second embodiment of the present application.

[0020] REFERENCE SIGNS: 100, end cover; 200, service nozzle; 300, fuel nozzle; 400, sealing ring; 1, end cover body; 101, first end face; 102, second end face; 103, through hole; 1031, first orifice; 1032, second orifice; 104, annular blind hole; 1041, first annular hole; 10411, large-diameter hole; 10412, small-diameter hole; 10413, sealing step surface; 1042, second annular hole; 105, premixed fuel passage; 1051, first-stage premixed fuel passage; 1052, second-stage premixed fuel passage; 106, first connecting flow channel; 107, second connecting flow channel. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0022] As Figures 1 to 3As shown, the end cover 100 of the embodiment of the present application comprises an end cover body 1 having a first end face 101 and a second end face 102 opposite along the thickness direction thereof, and a through hole 103 extending along the thickness direction thereof. The through hole 103 has a first aperture 1031 adjacent to the first end face 101 and used for mounting the duty nozzle 200, and a second aperture 1032 adjacent to the second end face 102 and used for communicating with the fuel nozzle 300. The second end face 102 is provided with an annular blind hole 104 surrounding the through hole 103 and used for communicating with the fuel nozzle 300. The end cover body 1 is further provided with a premixed fuel passage 105 communicating with the annular blind hole 104, so that the premixed fuel in the premixed fuel passage 105 is delivered into the fuel nozzle 300 through the annular blind hole 104.

[0023] The end cover body 1 of the embodiment of the present application is provided with two end faces (the first end face 101 and the second end face 102) and a through hole 103 in the thickness direction thereof. The through hole 103 is divided into a first aperture 1031 and a second aperture 1032, which are respectively used for mounting the duty nozzle 200 and communicating with the fuel nozzle 300. The end cover 100 is internally provided with a premixed fuel passage 105, which communicates with the annular blind hole 104, so that the premixed fuel can be delivered into the fuel nozzle 300 through the annular blind hole 104. The second aperture 1032 communicates with the fuel nozzle 300, ensuring that the fuel can be delivered from the premixed fuel passage 105 into the nozzle. The through hole 103 on the end cover 100 serves as an air flow channel, and the annular blind hole 104 on the end cover 100 serves as a fuel flow channel, both of which are separate flow channels for delivering air and fuel respectively, ensuring effective isolation of air and fuel, and thus realizing mixing and combustion with air.

[0024] The end cover 100 of the embodiment of the present application cancels the sealing insert part, adopts an integrated machining mode to form the through hole 103 for delivering air and the annular blind hole 104 for delivering premixed fuel, cancels the need for precious metal alloy brazing material, and reduces the material cost. The cancellation of the sealing connection insert improves the reliability of sealing and avoids the problem of sealing failure due to low brazing quality. Since the reliability problem of the brazing material under high temperature is eliminated, the integrated design makes the end cover 100 not need to be replaced regularly during long-term use, improving the stability and durability of the equipment. Since the brazing structure is cancelled, the maintenance work is simpler, the frequency and cost of repair and replacement are reduced, and the performance and safety problems caused by leakage or insufficient mixing are also avoided, improving the safety of gas turbine operation.

[0025] Optionally, the through hole 103 and the annular blind hole 104 are machined on a cylindrical forged piece of stainless steel (which can be AISI304L, AISI321, etc.) at corresponding positions using a milling cutter.

[0026] In some embodiments, the number of through holes 103 and annular blind holes 104 is multiple and one-to-one correspondence.

[0027] The end cover 100 is provided with multiple through holes 103 and annular blind holes 104, so multiple duty nozzles 200 and fuel nozzles 300 can be installed at the same time, thereby meeting the fuel distribution needs of larger scale. Each through hole 103 matches its corresponding annular blind hole 104, ensuring that each fuel nozzle 300 can independently receive premixed fuel, avoiding interference between fuel flow channels. The number of through holes 103 and annular blind holes 104 can be increased or decreased according to the specific needs of the gas turbine, achieving flexible configuration.

[0028] The arrangement of multiple through holes 103 and annular blind holes 104 can achieve uniform distribution of fuel, ensuring the stability of the combustion process inside the gas turbine. Multiple independent fuel flow channels can reduce the unevenness of fuel and air mixing, improving combustion efficiency. Even if a through hole 103 or annular blind hole 104 fails, other flow channels can still work normally, which improves the redundancy and reliability of the system.

[0029] In some embodiments, as shown in Figure 1 and Figure 2 The multiple annular blind holes 104 include spaced first annular holes 1041 and second annular holes 1042, and the premixed fuel passages 105 include first-stage premixed fuel passages 1051 and second-stage premixed fuel passages 1052. The premixing ratio of fuel and air in the first-stage premixed fuel passages 1051 is lower than that in the second-stage premixed fuel passages 1052, the first-stage premixed fuel passages 1051 communicate with the first annular holes 1041, and the second-stage premixed fuel passages 1052 communicate with the second annular holes 1042.

[0030] The end cover 100 is provided with multiple annular blind holes 104, which are divided into first annular holes 1041 and second annular holes 1042, and are spaced apart to adapt to different fuel premixing needs. The first-stage premixed fuel passages 1051 communicate with the first annular holes 1041, and the premixing ratio of fuel and air is lower, which is suitable for the preliminary mixing stage. The second-stage premixed fuel passages 1052 communicate with the second annular holes 1042, and the premixing ratio of fuel and air is higher, which is suitable for a more thorough mixing stage.

[0031] In the first-stage premixed fuel passages 1051, fuel and air are preliminarily mixed with a lower premixing ratio, which helps to control the combustion speed and temperature and reduce the generation of nitrogen oxides. In the second-stage premixed fuel passages 1052, the premixing ratio of fuel and air is higher, which can achieve more thorough mixing and improve combustion efficiency.

[0032] The first and second premix fuel passages 1051 and 1052 are in communication with the first and second annular holes 1041 and 1042, respectively, through which premixed fuel of different proportions is distributed to the corresponding fuel nozzles 300 for precise injection.

[0033] By staging the premixing, different mixing ratios can be achieved at different combustion stages, optimizing the combustion process and reducing pollutant emissions. Staged premixing helps to improve the combustion efficiency of the fuel, reduce fuel consumption, and improve the overall performance of the gas turbine. By precisely controlling the premixing ratio, the emission of pollutants such as nitrogen oxides can be reduced, meeting more stringent environmental requirements. By adjusting the fuel flow of the first and second premix fuel passages 1052, the combustion process can be flexibly adjusted to meet different operating conditions.

[0034] In some embodiments, as shown in Figure 2 The first annular hole 1041 includes a large-diameter hole 10411 and a small-diameter hole 10412, the inner diameter of the large-diameter hole 10411 is larger than that of the small-diameter hole 10412, and the large-diameter hole 10411 is adjacent to the second end face 102. The first premix fuel passage 1051 is in communication with the small-diameter hole 10412.

[0035] It can be understood that the first premix fuel passage 1051 first enters the small-diameter hole 10412 and then enters the large-diameter hole 10411. Since the inner diameter of the large-diameter hole 10411 is larger than that of the small-diameter hole 10412, the premixed fuel in the first premix fuel passage 1051 will flow in an expanding manner in the first annular hole 1041, which can improve the mixing uniformity at the outlet of the fuel nozzle 300, improve the uniformity of the fuel distribution inside the fuel nozzle 300, and have less impact on pressure loss. The non-uniformity at the fuel outlet of the first annular hole 1041 is reduced to within 1%.

[0036] In some embodiments, as shown in Figure 2 and Figure 3 The depth of the first annular hole 1041 is greater than the depth of the second annular hole 1042, and the first and second premix fuel passages 1051 and 1052 are arranged in the thickness direction of the end cover body 1, with the first premix fuel passage 1051 adjacent to the first end face 101 and the second premix fuel passage 1052 adjacent to the second end face 102. The spaced arrangement of the first and second premix fuel passages 1051 and 1052 can minimize their mutual influence, facilitate the processing and manufacturing of the first and second premix fuel passages 1051 and 1052, and enable independent control of the fuel flow and mixing in each passage.

[0037] In some embodiments, the end cover body 1 is provided with a first connecting flow channel 106, the cross section of the first connecting flow channel 106 is rectangular, and the extension direction of the first connecting flow channel 106 intersects with the axis of the through hole 103, and the first connecting flow channel 106 respectively communicates with the small-diameter hole 10412 and the first-stage premixed fuel passage 1051.

[0038] Specifically, as shown in Figure 2 , when the first-stage premixed fuel passage 1051 and the first connecting flow channel 106 are processed, the cross sections of the first-stage premixed fuel passage 1051 and the first connecting flow channel 106 are both rectangular, the first-stage premixed fuel passage 1051 perpendicular to the surface of the end cover body 1 can be first processed by using a lathe, and then the remaining first connecting flow channel 106 is processed by using a tool bit obliquely, so that the first connecting flow channel 106 communicates with the first-stage premixed fuel passage 1051 and the small-diameter hole 10412, and the first connecting flow channel 106 and the first-stage premixed fuel passage 1051 are simple and convenient to process and manufacture.

[0039] In some embodiments, as shown in Figure 3 , the end cover body 1 is provided with a second connecting flow channel 107, the extension direction of the second connecting flow channel 107 is perpendicular to the axis of the through hole 103, and the second connecting flow channel 107 respectively communicates with the second annular hole 1042 and the second-stage premixed fuel passage 1052.

[0040] Specifically, when the second connecting flow channel 107 is processed, a drill can be directly used to drill a hole, and then an electric spark or a laser is used to ream or root-removing, so that the second connecting flow channel 107 is processed, thereby making the second connecting flow channel 107 simple to process and manufacture.

[0041] In some embodiments, the annular blind hole 104 has a sealing step surface 10413 for placing a sealing ring 400.

[0042] Specifically, as shown in Figure 2 and Figure 3 , the abutting structure of the combustion nozzle 300 and the sealing step surface 10413 for installing the sealing ring are processed by turning and milling operations at the second end surface 102. In this embodiment, the sealing ring is an E-shaped sealing ring.

[0043] As shown in Figure 1 , the combustion chamber of the embodiment of the present application comprises an end cover 100, a duty nozzle 200, a fuel nozzle 300 and a sealing ring 400. The end cover 100 is any one of the end covers 100 in the above embodiments; the duty nozzle 200 is arranged at the first orifice 1031; the fuel nozzle 300 is connected with the end cover 100, and the fuel nozzle 300 communicates with the through hole 103 and the annular blind hole 104; and the sealing ring 400 is arranged between the second end surface 102 and the fuel nozzle 300.

[0044] Since the sealing insert is cancelled in the application, the end cover 1 is integrally formed, and the same material is used, so that the stress caused by temperature difference and brazing area structure can be effectively reduced in the test. In the original sealing insert brazing scheme end cover, since the sealing insert and the end cover are connected by brazing, there are many corners and discontinuous surface structures between the sealing insert and the end cover, so that there is a certain stress concentration problem in this area. The linear elastic numerical simulation calculation is performed on the original scheme, the maximum stress can reach 1700 MPa, which appears near the sealing connection insert and the end cover brazing, which is not conducive to the stability of the sealing structure. In the application, most of the corners caused by the brazing structure are eliminated, so the stress concentration problem is weakened, and the numerical simulation is performed in the same way, the highest stress is only about 700 MPa, which is conducive to the extension of the service life of the gas turbine. Since the connection structure with other parts can be formed by machining, the external connection structure of the original scheme end cover can be kept consistent, so the original scheme end cover can be directly replaced, and the compatibility is good.

[0045] The gas turbine of the embodiment of the application comprises the combustion chamber of any one of the above embodiments.

[0046] In the description of the application, it should be understood that the orientations or positional relationships 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" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0047] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0048] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixedly connected", "connection", "fixedly connected", "connected", "fixed", and the like should be construed broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0049] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "on", "above" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0050] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 application. In the present specification, the illustrative expressions 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 any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or features of different embodiments or examples described in the present specification without contradiction.

[0051] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. An end cap, characterized in that, The end cap body (1) includes a first end face (101) and a second end face (102) opposite each other along its thickness direction. The end cap body (1) has a through hole (103) extending along its thickness direction. The through hole (103) has a first opening (1031) and a second opening (1032). The first opening (1031) is disposed adjacent to the first end face (101) and is used to install a duty nozzle (200). The second opening (1032) is disposed adjacent to the second end face (102) and is used to install a duty nozzle (200). The second end face (102) is provided with an annular blind hole (104) for communicating with the fuel nozzle (300). The annular blind hole (104) surrounds the through hole (103) and is used to communicate with the fuel nozzle (300). The end cap body (1) is also provided with a premixed fuel channel (105) communicating with the annular blind hole (104) so ​​that the premixed fuel in the premixed fuel channel (105) is transported to the fuel nozzle (300) through the annular blind hole (104).

2. The end cap according to claim 1, characterized in that, The number of the through holes (103) and the annular blind holes (104) are multiple and correspond one-to-one.

3. The end cap according to claim 2, characterized in that, The plurality of annular blind holes (104) include a first annular hole (1041) and a second annular hole (1042) arranged at intervals. The premixed fuel channel (105) includes a primary premixed fuel channel (1051) and a secondary premixed fuel channel (1052). The premixing ratio of fuel and air in the primary premixed fuel channel (1051) is lower than that in the secondary premixed fuel channel (1052). The primary premixed fuel channel (1051) is connected to the first annular hole (1041), and the secondary premixed fuel channel (1052) is connected to the second annular hole (1042).

4. The end cap according to claim 3, characterized in that, The first annular hole (1041) includes a large-diameter hole (10411) and a small-diameter hole (10412). The inner diameter of the large-diameter hole (10411) is larger than the inner diameter of the small-diameter hole (10412), and the large-diameter hole (10411) is disposed adjacent to the second end face (102) relative to the small-diameter hole (10412). The primary premixed fuel channel (1051) is connected to the small-diameter hole (10412).

5. The end cap according to claim 4, characterized in that, The depth of the first annular hole (1041) is greater than the depth of the second annular hole (1042). The primary premixed fuel channel (1051) and the secondary premixed fuel channel (1052) are arranged at intervals in the thickness direction of the end cap body (1). The primary premixed fuel channel (1051) is disposed adjacent to the first end face (101) relative to the secondary premixed fuel channel (1052).

6. The end cap according to claim 5, characterized in that, The end cap body (1) is provided with a first connecting channel (106). The cross-section of the first connecting channel (106) is rectangular, and the extension direction of the first connecting channel (106) intersects the axis of the through hole (103). The first connecting channel (106) is connected to the small diameter hole (10412) and the primary premixed fuel channel (1051) respectively.

7. The end cap according to claim 5, characterized in that, The end cap body (1) is provided with a second connecting channel (107), the extension direction of the second connecting channel (107) is perpendicular to the axis of the through hole (103), and the second connecting channel (107) is connected to the second annular hole (1042) and the secondary premixed fuel channel (1052) respectively.

8. The end cap according to claim 1, characterized in that, The annular blind hole (104) has a sealing step surface (10413) for placing a sealing ring (400).

9. A combustion chamber, characterized in that, include: End cap, wherein the end cap is the end cap as described in any one of claims 1-8; A duty nozzle (200) is provided at the first orifice (1031). A fuel nozzle (300) is connected to the end cap and communicates with the through hole (103) and the annular blind hole (104). A sealing ring (400) is disposed between the second end face (102) and the fuel nozzle (300).

10. A gas turbine, characterized in that, Includes the combustion chamber as described in claim 9.

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