A heat shield fixing structure and fixing method for a gas turbine combustion chamber

Abstract

The present invention relates to the technical field of gas turbine combustion chambers, and in particular to a heat shield fixing structure of a gas turbine combustion chamber, comprising a heat shield element, a combustion chamber support structure, fixing bolts, a spring sheet, a spring and a directional pressure plate, wherein the bottom surface of the heat shield element fits the top surface of the combustion chamber support structure, and the countersunk mounting hole on the heat shield element is coaxial with the fixing hole on the combustion chamber support structure, the fixing bolt passes through the axial through hole, the countersunk mounting hole, the fixing hole and the spring of the spring sheet in sequence and is threadedly connected with the threaded hole of the directional pressure plate, the spring sheet is located in the countersunk mounting hole and the outer edge of the spring sheet abuts against the countersunk portion of the countersunk mounting hole, one end of the spring abuts against the bottom surface of the combustion chamber support structure, and the other end abuts against the directional pressure plate. When the combustion chamber support structure vibrates or the operating temperature changes greatly, the vibration force or the operating condition change force can be absorbed by the deformation of the spring sheet and the spring, and is suitable for heat shield elements with relatively low structural strength.

Description

Technical Field

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

[0002] Since the support structure of the gas turbine combustion chamber involves complex operating conditions such as normal temperature, high temperature and extremely high temperature during use, and the support structure of the combustion chamber has weak high temperature resistance, it is necessary to cooperate with heat shielding elements to block the high temperature; at the same time, since the support structure of the combustion chamber is also accompanied by a certain degree of vibration during use, in order to avoid damage to the heat shielding elements with weak structural strength due to vibration, the heat shielding elements must be fastened to the support structure of the combustion chamber.

[0003] At present, in order to achieve the fastening of heat shielding elements, various fixing holes are often opened on the support structure of the combustion chamber, which reduces the structural strength of the support structure of the combustion chamber. Although the heat shielding elements fixed by threaded groups disclosed in the Chinese patent publication No. 109312922 have fewer fixing holes opened on the support structure of the combustion chamber, the single fixing hole is larger, which also causes damage to the support structure of the combustion chamber, changes the natural frequency of the combustion chamber, is not conducive to the control of the thermoacoustic oscillation of the combustion chamber, and makes the threaded group easy to loosen under the action of the thermoacoustic oscillation of the combustion chamber. In addition, this fixing method can only be used for heat shielding elements with relatively high structural strength, such as high-temperature castings with coatings, and is less applicable to ceramic refractory bricks and carboxymethyl cellulose refractory bricks. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a heat shield fixing structure for a gas turbine combustion chamber which has little influence on a combustion chamber supporting structure and is suitable for heat shield elements with relatively low structural strength.

[0005] The present invention adopts the following technical solution:

[0006] The present invention provides a heat shield fixing structure of a gas turbine combustion chamber, comprising a heat shield element, a combustion chamber support structure, fixing bolts, a spring sheet, a spring and a directional pressure plate, wherein the bottom surface of the heat shield element is fitted with the top surface of the combustion chamber support structure, and the countersunk mounting hole on the heat shield element is coaxial with the fixing hole on the combustion chamber support structure, the fixing bolts pass through the axial through hole, the countersunk mounting hole, the fixing hole and the spring of the spring sheet in sequence, and are threadedly connected with the threaded hole of the directional pressure plate, the spring sheet is located in the countersunk mounting hole, and the outer edge of the spring sheet abuts against the countersunk part of the countersunk mounting hole, one end of the spring abuts against the bottom surface of the combustion chamber support structure, and the other end abuts against the directional pressure plate.

[0007] Preferably, a cooling hole is provided on the fixing bolt, and the cooling hole is connected to both axial ends of the fixing bolt.

[0008] Preferably, the middle portion of the fixing bolt is an optical axis segment with a diameter smaller than that of the two end portions.

[0009] Preferably, it also includes a guide cover, which is arranged on the bottom surface of the combustion chamber support structure. The part of the fixing bolt passing through the fixing hole, the spring and the directional pressure plate are all accommodated in the guide cover, and the directional pressure plate can move along the axial direction of the fixing bolt.

[0010] Preferably, it also includes a high temperature protection cover with a through hole, which is passed through the through hole on the fixing bolt and located between the head of the fixing bolt and the spring sheet, and is covered above the countersunk mounting hole on the heat shielding element.

[0011] Preferably, the high-temperature protection cover is provided with a plurality of first trapezoidal steps at equal intervals around the axis of the through-hole, the elevation angle of the first trapezoidal step on the counterclockwise side of the through-hole is 15° to 40°, the elevation angle of the first trapezoidal step on the clockwise side of the through-hole is 30° to 45°, and the head of the fixing bolt is provided with a plurality of second trapezoidal steps at equal intervals around the axis, the clearance between the first trapezoidal step and two adjacent second trapezoidal steps is matched, and the clearance between the second trapezoidal step and two adjacent first trapezoidal steps is matched.

[0012] Preferably, the spring is a butterfly spring.

[0013] The present invention further provides a method for fixing the heat shield fixing structure of the gas turbine combustion chamber as described in the seventh item above, comprising the following steps:

[0014] S1: insert the high temperature protection cover, the spring sheet, the heat shield element, the combustion chamber support structure and the spring on the fixing bolts in sequence, and thread the directional pressure plate with the fixing bolts;

[0015] S2: Install the guide cover on the bottom surface of the combustion chamber support structure, and place the portion of the fixing bolt that passes through the fixing hole, the spring and the directional pressure plate in the guide cover so that the directional pressure plate can move along the axial direction of the fixing bolt;

[0016] S3: Tighten the fixing bolts to fasten the high temperature protection cover, spring sheet, heat shield element, combustion chamber support structure and spring.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The heat shield fixing structure of the gas turbine combustion chamber of the present invention only needs to open a fixing hole on the combustion chamber support structure to allow the fixing bolts to pass through, so as to ensure the installation of other parts, and has little impact on the combustion chamber support structure. At the same time, when the combustion chamber support structure vibrates or the operating temperature changes significantly, the vibration force or the operating condition change force can be absorbed by the deformation of the spring sheet and the spring, ensuring the fastening of the fixing bolts and the positioning pressure plate to the entire structure. Therefore, it can be suitable for heat shield elements with relatively low structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional schematic diagram of a heat shield fixing structure of a gas turbine combustion chamber in an embodiment of the present invention.

[0020] Figure 2 It is a structural schematic diagram of a high temperature protection cover on a heat shield fixing structure of a gas turbine combustion chamber in an embodiment of the present invention.

[0021] Figure 3 It is a cross-sectional schematic diagram of a first trapezoidal platform of a high-temperature protection cover on a heat shield fixing structure of a gas turbine combustion chamber in an embodiment of the present invention.

[0022] Figure 4 It is a structural schematic diagram of fixing bolts on a heat shield fixing structure of a gas turbine combustion chamber in an embodiment of the present invention.

[0023] The reference numerals are described as follows:

[0024] 1. Heat shielding element 4. Spring sheet

[0025] 11. Countersunk mounting hole 5. Spring

[0026] 2. Combustion chamber support structure 6. Directional pressure plate

[0027] 21. Fixing hole 7. Guide cover

[0028] 3. Fixing bolt 8. High temperature protection cover

[0029] 31. Cooling hole 81. Piercing hole

[0030] 32. Second trapezoidal platform 82. First trapezoidal platform DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are 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 cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0035] See also Figures 1 to 4 , which is an embodiment of the heat shield fixing structure of the gas turbine combustion chamber of the present invention.

[0036] See also Figure 1 The heat shield fixing structure of the gas turbine combustion chamber of this embodiment includes a heat shield element 1, a combustion chamber support structure 2, a fixing bolt 3, a spring sheet 4, a spring 5 and a directional pressure plate 6. The bottom surface of the heat shield element 1 is in contact with the top surface of the combustion chamber support structure 2, and the countersunk mounting hole 11 on the heat shield element 1 is coaxial with the fixing hole 21 on the combustion chamber support structure 2. The fixing bolt 3 passes through the axial through hole of the spring sheet 4, the countersunk mounting hole 11, the fixing hole 21 and the spring 5 in sequence and is threadedly connected with the threaded hole of the directional pressure plate 6. The spring sheet 4 is located in the countersunk mounting hole 11 and the outer edge of the spring sheet 4 abuts against the countersunk part of the countersunk mounting hole 11. One end of the spring 5 abuts against the bottom surface of the combustion chamber support structure 2, and the other end abuts against the directional pressure plate 6.

[0037] The heat shield fixing structure of the gas turbine combustion chamber of this embodiment only needs to open a fixing hole 21 on the combustion chamber support structure 2 for the fixing bolt 3 to pass through, so as to ensure the installation of other parts, and has little impact on the combustion chamber support structure 2. The fixing hole 21 also has a certain cooling effect. At the same time, when the combustion chamber support structure 2 vibrates or the operating temperature changes significantly, the vibration force or the operating condition change force can be absorbed by the deformation of the spring sheet 4 and the spring 5, ensuring the fastening of the fixing bolt 3 and the positioning pressure plate 6 to the entire structure. Therefore, it can be suitable for heat shielding elements with relatively low structural strength such as ceramic refractory bricks and carboxymethyl cellulose refractory bricks.

[0038] It should be noted that when the initial setting position of the spring sheet 4 is offset, due to its own deformability, during the process of tightening the fixing bolt 3, it can be affected by the anisotropic deformation force on the spring sheet 4 and gradually move toward the axial position of the fixing bolt 3 as the tightening force increases, and finally reach coaxial with the fixing bolt 3.

[0039] Preferably, see Figure 1 The fixing bolt 3 is provided with a cooling hole 31, which is connected to both axial ends of the fixing bolt 3. The provision of the cooling hole 31 increases the contact area between the combustion chamber support structure 2 and the air during heat dissipation, thereby accelerating the cooling efficiency of the gas turbine combustion chamber.

[0040] Preferably, see Figure 1 and Figure 4 The middle part of the fixing bolt 3 is a light axis section with a diameter smaller than that of the two end parts. In actual use, the size of the gap between the fixing bolt 3 and the combustion chamber support structure 2 can be controlled by adjusting the axial position of the fixing bolt 3 relative to the combustion chamber support structure 2, thereby adjusting the cooling efficiency of the combustion chamber support structure 2.

[0041] It should be noted that, in actual use, the diameter of the middle portion of the fixing bolt 3 may be adjusted accordingly according to cooling requirements.

[0042] Preferably, see Figure 1 The heat shield fixing structure of the combustion chamber of the gas turbine of the present embodiment further comprises a guide cover 7, which is arranged on the bottom surface of the combustion chamber support structure 2. The portion of the fixing bolt 3 passing through the fixing hole 21, the spring 5 and the directional pressure plate 6 are all accommodated in the guide cover 7, and the directional pressure plate 6 can move along the axial direction of the fixing bolt 3. After the guide cover 7 and the directional pressure plate 6 cooperate, the axial distance between the fixing bolt 3 and the directional pressure plate 6 can be adjusted by axially rotating the fixing bolt 3, which is beneficial to the installation of the fixing bolt 3. At the same time, it also ensures that the elastic force of the spring 5 always acts in the axial direction.

[0043] Preferably, see Figure 1 and Figure 2 The heat shield fixing structure of the combustion chamber of the gas turbine of the present embodiment further includes a high temperature protection cover 8 with a through hole 81, the high temperature protection cover 8 is passed through the through hole 81 on the fixing bolt 3 and is located between the head of the fixing bolt 3 and the spring sheet 4, and the high temperature protection cover 8 is covered above the countersunk mounting hole 11 on the heat shield element 1. The high temperature protection cover 8 can prevent the heat of the combustion chamber support structure 2 from being dissipated in large quantities from the countersunk mounting hole 11 on the heat shield element 1.

[0044] Preferably, see Figures 2 to 4 The high temperature protection cover 8 is provided with a plurality of first trapezoidal platforms 82 at equal intervals around the axis of the through hole 81. The elevation angle of the first trapezoidal platform 82 on the counterclockwise side of the through hole 81 is 15° to 40°, and the elevation angle of the first trapezoidal platform 82 on the clockwise side of the through hole 81 is 30° to 45°. The head of the fixing bolt 3 is provided with a plurality of second trapezoidal platforms 32 at equal intervals around the axis. The first trapezoidal platform 82 is matched with the clearance between two adjacent second trapezoidal platforms 32, and the second trapezoidal platform 32 is matched with the clearance between two adjacent first trapezoidal platforms 82.

[0045] It should be noted that the thread on the fixing bolt 3 is a commonly used right-hand thread. When the fixing bolt 3 is tightened in the right direction, the first trapezoidal platform 82 has a table surface elevation angle of 15° to 40° on the counterclockwise side of the through hole 81 and does not hinder the tightening of the fixing bolt 3. When the fixing bolt 3 is loosened by left-hand rotation, the table surface elevation angle of 30° to 45° on the clockwise side of the through hole 81 of the first trapezoidal platform 82 makes the fixing bolt 3 self-locking, thereby preventing the fixing bolt 3 from loosening by left-hand rotation.

[0046] Preferably, the spring 5 is a disc spring. Due to the variable stiffness characteristics of the disc spring, when the fixing bolt 3 is tightened into place, the deformation of the spring 5 can be determined by the torque and the number of turns combined with the load deformation characteristic curve of the disc spring to determine whether the designed preload has been reached.

[0047] This embodiment also provides a method for fixing the heat shield fixing structure of the gas turbine combustion chamber as described above, comprising the following steps:

[0048] S1: The high temperature protection cover 8, the spring sheet 4, the heat shield element 1, the combustion chamber support structure 2 and the spring 5 are sequentially inserted into the fixing bolt 3, and the directional pressure plate 6 is threadedly connected to the fixing bolt 3;

[0049] S2: Install the guide cover 7 on the bottom surface of the combustion chamber support structure 2, and place the portion of the fixing bolt 3 that passes through the fixing hole 21, the spring 5 and the directional pressure plate 6 in the guide cover 7, so that the directional pressure plate 6 can move along the axial direction of the fixing bolt 3;

[0050] S3: Tighten the fixing bolts 3 to fasten the high temperature protection cover 8, the spring sheet 4, the heat shield element 1, the combustion chamber support structure 2 and the spring 5.

[0051] The fixing method of the heat shield fixing structure of the gas turbine combustion chamber can realize the precise installation of the heat shield fixing structure of the gas turbine combustion chamber of this embodiment, and ensure the fixing effect of the heat shield fixing structure of the gas turbine combustion chamber.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A heat shield fixing structure for a gas turbine combustion chamber, characterized in that: The invention comprises a heat shielding element (1), a combustion chamber support structure (2), a fixing bolt (3), a spring sheet (4), a spring (5), a directional pressure plate (6), a guide cover (7), and a high-temperature protection cover (8) having a through hole (81). The bottom surface of the heat shielding element (1) is in contact with the top surface of the combustion chamber support structure (2), and the countersunk mounting hole (11) on the heat shielding element (1) is coaxial with the fixing hole (21) on the combustion chamber support structure (2). The middle portion of the fixing bolt (3) is a light axis section with a diameter smaller than that of the two end portions. The fixing bolt (3) passes through the through hole (81) in sequence. The axial through hole of the spring sheet (4), the countersunk mounting hole (11), the fixing hole (21) and the spring (5) are threadedly connected to the threaded hole of the directional pressure plate (6); the spring sheet (4) is located in the countersunk mounting hole (11) and the outer edge of the spring sheet (4) abuts against the countersunk portion of the countersunk mounting hole (11); one end of the spring (5) abuts against the bottom surface of the combustion chamber support structure (2) and the other end abuts against the directional pressure plate (6); the guide cover (7) is arranged on the bottom surface of the combustion chamber support structure (2); the fixing bolt (3) passes through the bottom surface of the combustion chamber support structure (2); The portion protruding from the fixing hole (21), the spring (5) and the directional pressure plate (6) are all accommodated in the guide cover (7), and the directional pressure plate (6) is capable of moving along the axial direction of the fixing bolt (3), the high-temperature protection cover (8) is passed through the through hole (81) on the fixing bolt (3) and is located between the head of the fixing bolt (3) and the spring sheet (4), and the high-temperature protection cover (8) is arranged above the countersunk mounting hole (11) on the heat shielding element (1), and the high-temperature protection cover (8) is evenly spaced around the axis of the through hole (81). A plurality of first trapezoidal platforms (82) are arranged around the connecting hole (81), the platform surface of the first trapezoidal platform (82) having an elevation angle of 15° to 40° on the counterclockwise side of the connecting hole (81), and the platform surface of the first trapezoidal platform (82) having an elevation angle of 30° to 45° on the clockwise side of the connecting hole (81). A plurality of second trapezoidal platforms (32) are arranged around the head of the fixing bolt (3) at equal intervals around the axis, the clearance between the first trapezoidal platform (82) and two adjacent second trapezoidal platforms (32) is matched, and the clearance between the second trapezoidal platform (32) and two adjacent first trapezoidal platforms (82) is matched.

2. The heat shield fixing structure of the gas turbine combustion chamber according to claim 1, characterized in that: The fixing bolt (3) is provided with a cooling hole (31), and the cooling hole (31) is connected to two axial ends of the fixing bolt (3).

3. The heat shield fixing structure of the gas turbine combustion chamber according to claim 1, characterized in that: The spring (5) is a butterfly spring.

4. The method for fixing the heat shield fixing structure of the gas turbine combustion chamber according to claim 3, characterized in that: The following steps are involved: S1: sequentially inserting the high-temperature protection cover (8), the spring sheet (4), the heat shielding element (1), the combustion chamber support structure (2), and the spring (5) onto the fixing bolt (3), and threading the directional pressure plate (6) to the fixing bolt (3); S2: installing the guide cover (7) on the bottom surface of the combustion chamber support structure (2), and accommodating the portion of the fixing bolt (3) protruding from the fixing hole (21), the spring (5) and the directional pressure plate (6) in the guide cover (7), so that the directional pressure plate (6) can move along the axial direction of the fixing bolt (3); S3: Tighten the fixing bolts (3) to fasten the high-temperature protection cover (8), the spring sheet (4), the heat shield element (1), the combustion chamber support structure (2) and the spring (5).

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