Head structure of combustion chamber of gas turbine

Abstract

The invention relates to the technical field of gas turbines, and particularly discloses a gas turbine combustion chamber head structure which is characterized in that a circular boss with an annular groove and a cover plate on the outer edge extends inwards from a main gas impact area on the inner wall of a head end plate, and an annular gas inlet gap is reserved between the circular boss and the inner wall of a flow guide bushing; a plurality of air inlet holes extending into the annular groove are evenly distributed in the side face of the outer circumference of the boss, and a plurality of exhaust holes are inwards distributed in the inner side of the annular groove and penetrate through the interior of a gap area of the adjacent main combustion nozzles. According to the invention, the circular boss with the slotted cover plate is arranged in the main gas impact area in the head end plate, so that a heat insulation ring cavity is formed, main gas is guided to penetrate through the interior of a gap area between adjacent main combustion nozzles on the end plate and then is discharged, and the roots of the nozzles are inserted into a fuel pipe; the temperature gradient of the main gas impact area on the head end plate, the gap area between the adjacent main combustion nozzles and the connecting area of the head end plate and the fuel pipe can be reduced, the thermal stress and strain of the head structure are reduced, and the service life is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbine combustion chambers, in particular to a gas turbine combustion chamber head structure. Background Art

[0002] A gas turbine is a heat engine that converts the chemical energy of fuel into the kinetic energy of the impeller. It is widely used in power generation, ships, gas transmission and other fields. The combustion reaction in the combustion chamber provides an important energy source for the gas turbine. The combustion chamber head structure must withstand large internal and external temperature and pressure differences during operation. The head end plate area of ​​the commonly used countercurrent combustion chamber that is impacted by the main gas has a large temperature gradient. The inserted nozzle structure will produce a large shape change in the connection area with the head end plate, resulting in a large temperature gradient. The low temperature fuel rushing into the head end plate will also form a large temperature gradient in the connection area between the head end plate and the fuel pipe, causing large thermal stress and thermal strain to the head structure, affecting the service life of the head. In theory, as the number of main burners increases, the combustion will be more uniform around the circumference, the combustion efficiency will be improved, the pollutants will decrease, the hot spots will be reduced, and the service life of the structure will increase. However, as the number of main burners increases, the gaps between the main burners on the head end plate will increase. These gaps will form continuous stress risk areas, reducing the service life of the head structure. Considering the cost and safety aspects, the head end plate of the combustion chamber is generally made of thicker stainless steel forgings. The linear expansion coefficient of stainless steel is large, and it is easy to produce excessive thermal stress due to the increase in temperature difference, which affects the service life. Therefore, it is urgent to find a method to reduce the thermal stress and thermal strain of the combustion chamber head structure and extend the service life of the head structure. For this purpose, a gas turbine combustion chamber head structure is provided. Summary of the invention

[0003] The purpose of the present invention is to provide a gas turbine combustion chamber head structure in view of the defects of the prior art, so as to solve the problems raised by the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a gas turbine combustion chamber head structure, comprising a combustion chamber head structure, the combustion chamber head structure comprising a head end plate, an on-duty nozzle arranged at the inner center of the head end plate, and a plurality of main combustion nozzles surrounding the on-duty nozzle; a circular boss extends inwardly from the inner side of the head end plate, an annular groove is provided in the area of ​​the outer edge of the boss impacted by the main gas, a cover plate is welded on the annular groove, a gap is reserved between the outer circumference of the boss and the inner wall of the guide bushing to form an annular air inlet channel, a plurality of air inlet holes connecting the annular air inlet channel and the annular groove are evenly distributed on the side surface of the outer circumference of the boss, a plurality of first exhaust holes are evenly distributed in the gap area between adjacent main combustion nozzles inwardly of the annular groove, after the first exhaust hole extends toward the center direction of the head end plate, it turns in the direction to communicate with the second exhaust hole, and the second exhaust hole is communicated with the inside of the combustion chamber; the roots of the on-duty nozzle and the main combustion nozzle penetrate into the inside of the fuel pipe, and the penetrated part forms a circumferentially uniform gap with the inner wall of the fuel pipe;

[0005] A main combustion nozzle sealing gasket and a duty nozzle sealing gasket are arranged between the duty nozzle and the head end plate, and a duty stop washer and a main combustion stop washer are arranged between the main combustion nozzle and the head end plate.

[0006] As a preferred technical solution of the present invention, the head end plate is connected to the casing flange, the guide bushing is fitted to the head end plate through the casing flange, and a flange sealing gasket is provided between the guide bushing and the head end plate.

[0007] As a preferred technical solution of the present invention, the depth of the annular groove is equal to the height of the boss extending inwardly from the head end plate, and the cross-sectional area of ​​the annular groove is sufficient to allow 1-3% of the main gas flow to pass through the cross-section of the annular groove.

[0008] As a preferred technical solution of the present invention, the circular boss extending from the head end plate and the inner wall of the guide bushing form an annular air inlet channel, the cross-sectional area of ​​the annular air inlet channel is sufficient to introduce 1-3% of the main air flow rate, the number of air inlet holes evenly distributed on the outer circumferential side of the boss is equal to the number of main combustion nozzles, and the total area of ​​the air inlet holes is equal to the cross-sectional area of ​​the annular air inlet channel.

[0009] As a preferred technical solution of the present invention, after the first exhaust hole passes through the gap area between adjacent main combustion nozzles on the head end plate, it turns to form the second exhaust hole in the area between the main combustion nozzle and the duty nozzle.

[0010] As a preferred technical solution of the present invention, the number of the first exhaust holes and the second exhaust holes is equal to the number of the main combustion nozzles, and they are evenly distributed between each adjacent two main combustion nozzles, and the cross-sectional area of ​​the first exhaust holes and the second exhaust holes is equal to the cross-sectional area of ​​the air inlet hole.

[0011] As a preferred technical solution of the present invention, the bottom corners of the annular groove are rounded, and semicircular reinforcing bosses are distributed on the bottom of the annular groove and the outer side of the cover plate; the service nozzle is connected to the head end plate through a thread and locked with a service stop washer; the main combustion nozzle is evenly distributed in a circle around the service nozzle, the main combustion nozzle is connected to the head end plate through a thread and locked with a main combustion stop washer, and the service nozzle and the main combustion nozzle are both machined with mounting grooves matching the stop washers.

[0012] As a preferred technical solution of the present invention, the roots of the duty nozzle and the main combustion nozzle extend into the interior of the fuel pipe, the depth is L, the inner diameter of the fuel pipe is D, and it satisfies 0.4D≤L≤0.6D, the radial clearance between the roots of the duty nozzle and the main combustion nozzle and the inner wall of the fuel pipe is δ, and it satisfies 0.5mm≤δ≤1mm.

[0013] As a preferred technical solution of the present invention, the annular groove of the head end plate is processed by a CNC machine tool or is formed by welding the enclosure, and the air inlet hole needs to be processed in advance on the enclosure.

[0014] As a preferred technical solution of the present invention, the air inlet hole and the first exhaust hole and the second exhaust hole are circumferentially located at the same angle or are staggered and evenly distributed. When staggered and evenly distributed, the circumferential angle of each air inlet hole is consistent with the circumferential angle of each main combustion nozzle, and each first exhaust hole and the second exhaust hole are still arranged in the middle of the gap area between each adjacent main combustion nozzle.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The gas turbine head structure provided by the present invention forms a local heat-insulating annular cavity by extending a circular boss with an annular groove and a cover plate from the area impacted by the main gas on the inner side of the head end plate, so as to introduce a small amount of main gas, pass through the gap area between two adjacent main combustion nozzles on the end plate and then turn to be discharged into the combustion chamber. Without adding additional heating to the main gas, the temperature gradient of the area impacted by the main gas inside the head end plate can be reduced, the temperature gradient of the gap area between adjacent main combustion nozzles on the head end plate can be reduced, the thermal stress and thermal strain of the head end plate can be reduced, and the service life of the head end plate can be extended.

[0017] (2) The gas turbine head structure provided by the present invention can increase the number of circumferentially arranged main combustion nozzles by reducing the thermal stress and thermal strain in the gap area between adjacent main combustion nozzles, thereby making the combustion more uniform, improving the combustion efficiency, reducing hot spots, and increasing the life of the gas turbine components.

[0018] (3) The gas turbine head structure provided by the present invention can, under a relatively low stress level, increase the size of the gas turbine combustion chamber head structure by increasing the radial extension length of the insulation ring cavity and the exhaust hole, thereby forming a larger Helmholtz resonance cavity in the combustion chamber head and reducing the hazards of thermoacoustic oscillations. The insulation ring cavity can also form a local Helmholtz resonance cavity and reduce the hazards of thermoacoustic oscillations of a specific frequency.

[0019] (4) The present invention pushes the nozzle root deep into the fuel pipe so that the low-temperature fuel can enter the nozzle before impacting the end plate. The nozzle material is high-temperature resistant and can withstand a large temperature gradient, thereby reducing the temperature gradient, thermal stress, and thermal strain in the connection area between the head end plate and the fuel pipe, thereby extending the service life of the head structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the combustion chamber head structure;

[0021] Figure 2 It is a schematic diagram of the airflow in the annular cavity;

[0022] Figure 3 This is a schematic diagram of the radially staggered arrangement of the inlet and outlet holes of the annular cavity;

[0023] Figure 4 This is a schematic diagram of the welded enclosure plate used on the outer side of the ring cavity circumference;

[0024] Figure 5 It is a schematic diagram of the locking method between the nozzle and the head end plate;

[0025] Figure 6 The comparison diagrams of equivalent stress before and after the end plate of the rear head of the thermal insulation ring cavity (a) and (b), and the comparison diagrams of equivalent strain (c) and (d).

[0026] In the figure: 100, combustion chamber head structure; 101, head end plate; 102, cover plate; 103, main combustion nozzle gasket; 104, fuel pipe; 105, duty nozzle gasket; 106, flange gasket; 107, guide bushing; 108, casing flange; 109, duty nozzle; 110, duty stop washer; 111, main combustion nozzle; 112, main combustion stop washer; 113, enclosure; a-1, annular air inlet channel; a-2, air inlet hole; b, annular groove; c-1, first exhaust hole; c-2, second exhaust hole; c-3, process hole; L, distance of nozzle root into fuel pipe; D, inner diameter of fuel pipe; δ, radial clearance between nozzle root and inner wall of fuel pipe. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0028] Example: Figure 1 As shown, a combustion chamber head structure of a gas turbine includes a combustion chamber head structure 100, the combustion chamber head structure 100 includes a head end plate 101, a service nozzle 109 arranged at the inner center of the head end plate 101, and a plurality of main combustion nozzles 111 surrounding the service nozzle 109; a circular boss extends inward from the inner side of the head end plate 101, an annular groove b is provided in the area of ​​the outer edge of the boss impacted by the main gas, a cover plate 102 is welded on the annular groove b, a gap is reserved between the outer circumference of the boss and the inner wall of the guide bushing 107, forming an annular air inlet channel a-1, the boss A plurality of air inlet holes a-2 connecting the annular air inlet channel a-1 and the annular groove b are evenly distributed on the outer circumferential side surface of the platform. A plurality of first exhaust holes c-1 are evenly distributed in the gap area between adjacent main combustion nozzles 111 inwardly of the annular groove b. After the first exhaust holes c-1 extend toward the center direction of the head end plate 101, they turn and connect with the second exhaust holes c-2. The second exhaust holes c-2 connect with the interior of the combustion chamber. The roots of the duty nozzle 109 and the main combustion nozzle 111 penetrate into the interior of the fuel pipe 104, and the penetrated parts form a circumferentially uniform gap with the inner wall of the fuel pipe 104.

[0029] like Figure 1 As shown, a main combustion nozzle sealing gasket 103 and a main combustion nozzle sealing gasket 105 are provided between the service nozzle 109 and the head end plate 101 , and a service stop washer 110 and a main combustion stop washer 112 are provided between the main combustion nozzle 111 and the head end plate 101 .

[0030] like Figure 1-2 As shown, the head end plate 101 is connected to the casing flange 108 , the guide bushing 107 is attached to the head end plate 101 through the casing flange 108 , and a flange sealing gasket 106 is provided between the guide bushing 107 and the head end plate 101 .

[0031] like Figure 1-3 As shown, the depth of the annular groove b is equal to the height of the boss extending inward from the head end plate 101, and the cross-sectional area of ​​the annular groove b is sufficient to allow 1-3% of the main gas flow to pass through the cross-section of the annular groove b. The convection heat exchange of a small amount of main gas is utilized to reduce the temperature gradient and thermal stress in the area of ​​the head end plate impacted by the main gas.

[0032] like Figure 1-2As shown, the circular boss extending from the head end plate 101 and the inner wall of the guide bushing 107 form an annular air inlet channel a-1, the cross-sectional area of ​​the annular air inlet channel a-1 is sufficient to introduce 1-3% of the main air flow rate, the number of air inlet holes a-2 evenly distributed on the outer circumferential side of the boss is equal to the number of the main combustion nozzles 111, and the total area of ​​the air inlet holes a-2 is equal to the cross-sectional area of ​​the annular air inlet channel a-1.

[0033] like Figure 1-3 As shown, after the first exhaust hole c-1 passes through the gap area between adjacent main combustion nozzles 111 on the head end plate 101, it turns in the area between the main combustion nozzle 111 and the duty nozzle 109 to form the second exhaust hole c-2, and is discharged into the interior of the combustion chamber, using the convective heat exchange of a small amount of main gas to reduce the stress concentration in the gap area between adjacent main combustion nozzles.

[0034] like Figure 1 As shown, the number of the first exhaust holes c-1 and the second exhaust holes c-2 is equal to the number of the main combustion nozzles 111, and are evenly distributed between each adjacent two main combustion nozzles 111, and the cross-sectional area of ​​the first exhaust holes c-1 and the second exhaust holes c-2 is equal to the cross-sectional area of ​​the air inlet hole a-2.

[0035] like Figure 1-2 As shown, the bottom corners of the annular groove b are rounded, and semicircular reinforcing bosses are distributed on the bottom of the annular groove b and the outer side of the cover plate 102; the duty nozzle 109 is connected to the head end plate 101 through a thread and is locked with a duty stop washer 110; the main combustion nozzle 111 is evenly distributed in a circle around the duty nozzle 109, the main combustion nozzle 111 is connected to the head end plate 101 through a thread and is locked with a main combustion stop washer 112, and the duty nozzle 109 and the main combustion nozzle 111 are both machined with mounting grooves matching the stop washers.

[0036] like Figure 1 As shown, the roots of the service nozzle 109 and the main combustion nozzle 111 extend into the interior of the fuel pipe, the penetration distance is L, the inner diameter of the fuel pipe 104 is D, and it satisfies 0.4D≤L≤0.6D, the radial clearance between the roots of the service nozzle 109 and the main combustion nozzle 111 and the inner wall of the fuel pipe 104 is δ, and it satisfies 0.5mm≤δ≤1mm, so that the low-temperature fuel does not directly impact the head end plate, reducing the temperature gradient and thermal stress in the connection area between the head end plate and the fuel pipe.

[0037] like Figure 4 As shown, the annular groove b of the head end plate 101 is processed by a CNC machine tool or by welding the enclosure 113. The air inlet a-2 needs to be processed in advance on the enclosure 113. This method can shorten the drilling length of the exhaust hole c-1 and is suitable for the annular cavity processing of the head flange of larger size.

[0038] like Figure 3As shown, the air inlet hole a-2 and the first exhaust hole c-1 and the second exhaust hole c-2 are located at the same angle in the circumferential direction or are staggered and evenly distributed. When they are staggered and evenly distributed, the circumferential angle of each air inlet hole a-2 is consistent with the circumferential angle of each main combustion nozzle 111, and each first exhaust hole c-1 and second exhaust hole c-2 is still arranged in the middle of the gap area between each adjacent main combustion nozzle 111. This structure requires that the process hole C-3 of the outer circle be blocked after the hole is processed.

[0039] Working principle: A gas turbine combustion chamber head structure, reference Figure 1 As shown, after the annular groove b is processed on the head end plate 101, the inlet and outlet holes are processed by drilling equipment, and then the cover plate 102 and the fuel pipe 104 are welded to the head end plate 101; then, the main combustion nozzle sealing gasket 103 and the duty nozzle sealing gasket 105 are installed, and the duty nozzle 109 and the main combustion nozzle 111 are tightened to ensure the matching clearance between the nozzle root and the inner wall of the fuel pipe, and then the duty stop washer 110 and the main combustion stop washer 112 are locked; then, the flange sealing gasket 106, the guide bushing 107, the casing flange 108, etc. are installed to form the following. Figure 2 The local flow route of the main gas indicated by the arrows, which consists of the annular air inlet channel a-1, the air inlet hole a-2, the annular groove b, the first exhaust hole c-1, and the second exhaust hole c-2, utilizes the convective heat exchange of a small amount of main gas to reduce the temperature gradient in the area impacted by the main gas inside the head end plate 101, and reduce the stress concentration in the gap area between adjacent main combustion nozzles 111, thereby reducing the thermal stress and thermal strain on the inner side of the head end plate 101. The root of the nozzle penetrates deep into the fuel pipe 104 to prevent low-temperature fuel from directly impacting the head end plate 101, reduce the thermal stress and thermal strain in the connection area between the head end plate 101 and the fuel pipe 104, and extend the service life of the head structure.

[0040] Reference Figure 2 As shown, the air inlet a-2 and the first exhaust hole c-1 and the second exhaust hole c-2 may be located at the same angle in the circumferential direction, or as shown in FIG. Figure 3 As shown, they are staggered and evenly distributed. When they are staggered and evenly distributed, the circumferential angle of each air inlet hole a-2 is consistent with the circumferential angle of each main combustion nozzle 111, and each exhaust hole is still arranged in the middle of the gap area between each adjacent main combustion nozzle 111. This structure requires that the process holes of the outer circle be blocked after the holes are processed.

[0041] The annular groove b of the head end plate 101 can be machined or processed as follows. Figure 4 As shown, it is made of welded enclosure 113, and the air inlet hole needs to be processed in advance on the enclosure 113. This method can shorten the drilling length of the exhaust hole c-1 and is suitable for the ring cavity processing of the head flange of larger size.

[0042] Reference Figure 1As shown, the duty nozzle 109 is located at the center of the head end plate 101, connected to the head end plate 101 through threads, and locked with a duty stop washer 110; the main combustion nozzles 111 are evenly distributed around the duty nozzle 109. In this embodiment, the number of the main combustion nozzles 111 is 11, which are also connected to the head end plate 101 through threads and locked with a main combustion stop washer 112. Figure 5 As shown, the duty stop washer 110 and the main combustion stop washer 112 are non-standard round nut stop washers, and the mounting grooves of the washers need to be processed on the duty nozzle 109 and the main combustion nozzle 111.

[0043] The gas and main gas flow domains formed by the head end plate 101, cover plate 102, fuel pipe 104, guide bushing 107, casing flange 108, service nozzle 109, main combustion nozzle 111, etc. are extracted, and the thermal fluid-solid coupling calculation is performed by coupling the solid structure. The thermal stress and thermal strain of the head end plate without and with the thermal insulation ring cavity are compared. Figure 6 As shown in a and b, the high stress area of ​​the head end plate 101 after the insulation ring cavity is set is significantly reduced. As shown in reference 6c and d, the equivalent strain of the head end plate 101 after the insulation ring cavity is set is significantly reduced, and the equivalent strain of the gap area between adjacent main combustion nozzles 111 is also significantly reduced, with a reduction of more than half, and the service life is significantly improved.

[0044] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A gas turbine combustion chamber head structure, comprising a combustion chamber head structure (100), characterized in that: The combustion chamber head structure (100) comprises a head end plate (101), a service nozzle (109) arranged at the inner center of the head end plate (101), and a plurality of main combustion nozzles (111) surrounding the service nozzle (109); a circular boss extends inward from the inner side of the head end plate (101), an annular groove (b) is provided in the area of ​​the outer edge of the boss impacted by the main gas, a cover plate (102) is welded on the annular groove (b), a gap is reserved between the outer circumference of the boss and the inner wall of the guide bushing (107), forming an annular air intake channel (a-1), and a plurality of connecting rings are evenly distributed on the outer circumferential side of the boss. The annular groove (b) has an air inlet channel (a-1) and an air inlet hole (a-2), and the annular groove (b) has a plurality of first exhaust holes (c-1) uniformly distributed in the gap area between adjacent main combustion nozzles (111). After the first exhaust holes (c-1) extend toward the center of the head end plate (101), they turn and communicate with the second exhaust holes (c-2), and the second exhaust holes (c-2) communicate with the interior of the combustion chamber; the roots of the service nozzle (109) and the main combustion nozzle (111) penetrate into the interior of the fuel pipe (104), and the penetrated parts form a circumferentially uniform gap with the inner wall of the fuel pipe (104); A main combustion nozzle sealing gasket (103) and a main combustion nozzle sealing gasket (105) are provided between the service nozzle (109) and the head end plate (101), and a service stop washer (110) and a main combustion stop washer (112) are provided between the main combustion nozzle (111) and the head end plate (101).

2. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The head end plate (101) is connected to the casing flange (108), the guide bushing (107) is fitted to the head end plate (101) via the casing flange (108), and a flange sealing gasket (106) is provided between the guide bushing (107) and the head end plate (101).

3. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The depth of the annular groove (b) is equal to the height of the boss extending inwardly from the head end plate (101), and the cross-sectional area of ​​the annular groove (b) is sufficient to allow 1-3% of the main gas flow to pass through the cross-section of the annular groove (b).

4. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The circular boss extending from the head end plate (101) and the inner wall of the guide bushing (107) form an annular air inlet channel (a-1), the cross-sectional area of ​​the annular air inlet channel (a-1) is sufficient to introduce 1-3% of the main air flow rate, the number of air inlet holes (a-2) evenly distributed on the outer circumferential side of the boss is equal to the number of the main combustion nozzles (111), and the total area of ​​the air inlet holes (a-2) is equal to the cross-sectional area of ​​the annular air inlet channel (a-1).

5. The gas turbine combustion chamber head structure according to claim 1, characterized in that: After the first exhaust hole (c-1) passes through the gap area between adjacent main combustion nozzles (111) on the head end plate (101), it turns to form a second exhaust hole (c-2) in the area between the main combustion nozzle (111) and the duty nozzle (109).

6. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The number of the first exhaust holes (c-1) and the second exhaust holes (c-2) is equal to the number of the main combustion nozzles (111), and they are evenly distributed between each two adjacent main combustion nozzles (111); the cross-sectional area of ​​the first exhaust holes (c-1) and the second exhaust holes (c-2) is equal to the cross-sectional area of ​​the air inlet hole (a-2).

7. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The bottom corners of the annular groove (b) are rounded, and the bottom of the annular groove (b) and the outer side of the cover plate (102) are provided with semicircular reinforcing bosses; the duty nozzle (109) is connected to the head end plate (101) through a thread and is locked with a duty stop washer (110); the main combustion nozzle (111) is evenly distributed in a circle around the duty nozzle (109), the main combustion nozzle (111) is connected to the head end plate (101) through a thread and is locked with a main combustion stop washer (112), and the duty nozzle (109) and the main combustion nozzle (111) are both processed with mounting grooves matching the stop washers.

8. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The roots of the service nozzle (109) and the main combustion nozzle (111) extend into the fuel pipe, the depth is L, the inner diameter of the fuel pipe (104) is D, and 0.4D≤L≤0.6D is satisfied, the radial clearance between the roots of the service nozzle (109) and the main combustion nozzle (111) and the inner wall of the fuel pipe (104) is δ, and 0.5mm≤δ≤1mm is satisfied.

9. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The annular groove (b) of the head end plate (101) is processed by a numerically controlled machine tool or is formed by welding the enclosure plate (113), and the air inlet hole (a-2) needs to be processed in advance on the enclosure plate (113).

10. The gas turbine combustion chamber head structure according to claim 1, characterized in that: The air inlet holes (a-2) are circumferentially located at the same angle as the first exhaust holes (c-1) and the second exhaust holes (c-2) or are evenly distributed in a staggered manner. When the air inlet holes (a-2) are evenly distributed in a staggered manner, the circumferential angle of each air inlet hole (a-2) is consistent with the circumferential angle of each main combustion nozzle (111), and each first exhaust hole (c-1) and the second exhaust hole (c-2) are still arranged in the middle of the gap area between each adjacent main combustion nozzle (111).

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