A combustion chamber flame tube modal test fixture device

Abstract

The present invention discloses a fixture used for testing the flame tube of a gas turbine combustion chamber, wherein the fixture supports the two parts of the flame tube respectively through two supporting structures. The first supporting structure rigidly fixes the first end of the workpiece to be tested by using a supporting assembly, a limiting assembly and a fixing assembly, and at the same time ensures that the parts can be easily replaced by designing a detachable structure. The second clamping structure includes a supporting structure and an elastic supporting structure, which can ensure that the other end of the part to be tested is non-rigidly connected to the test bench. By clamping the two clamping devices, the actual assembly environment of the flame tube can be simulated, thereby obtaining more accurate modal parameters, in order to correct and guide the finite element analysis, obtain a finite element model and analysis method that is more consistent with the test results, improve the accuracy of the finite element method, thereby saving test costs and improving R&D efficiency.

Description

Technical Field

[0001] The present invention relates to a tool for fixing a combustion chamber flame tube of a gas turbine during a modal test, in particular to a fixture required for testing the combustion chamber flame tube of a heavy-duty gas turbine. Background Art

[0002] The combustion chamber is the chamber in a gas turbine where fuel burns, and one of its core components is the flame liner. During operation, the combustion liner is subject to various excitation forces, including combustion pulsations and overall vibration. These vibrations can cause failures during combustion chamber operation. Furthermore, when the combustion liner is subjected to time-varying loads, components vibrate, generating alternating stresses. If the energy transmitted by the excitation forces cannot be converted into component kinetic energy or absorbed by damping, the components will continue to vibrate for a certain stress cycle coefficient, eventually leading to cracks or fractures, resulting in vibration failure. Therefore, understanding the vibration characteristics of the combustion liner structure and verifying the rationality of its structural dynamic design are essential.

[0003] Experimental modal analysis, also known as the experimental process of modal analysis, or simply modal testing, is a method for verifying the reliability of theoretical modal analysis and finite element analysis. It is also a necessary and effective means of structural dynamics analysis and is currently widely used in defense industries such as aviation, aerospace, weapons, shipbuilding, and the nuclear industry, as well as civilian industries such as automobiles and construction. The modal test apparatus primarily includes a fixture, an exciter, force sensors and accelerometers, a data acquisition system, and a measurement system. The fixture is a crucial component of the modal test apparatus. Proper fixture design for the test piece during modal testing is fundamental to conducting modal tests. In existing technologies, the modal test apparatus for the flame tube of a heavy-duty gas turbine combustor provides a free boundary, simulating the test piece's lack of any constraints on the ground. Conventional methods for simulating a free boundary include: rubber rope suspension, sponge pad support, airbag support, rubber pad support, air spring support, and soft elastic support or suspension.

[0004] Prior art CN112485015A discloses a test bench for a gas turbine combustion chamber. Its main technical advantage lies in the use of two front and rear flanges to fix the flame tube. The fixing structure is designed to support the front and rear ends of the flame tube. The front end is fixed by a flange and a positioning plate, and the rear end is fixed by a support plate. Specifically, the application discloses a test platform for the combustion chamber, which includes a structure for fixing the flame tube. The flame tube in this test bench is cylindrical in shape, with a smaller opening at the front and a larger opening at the rear end. Specifically, in terms of the fixing method, the front end of the flame tube in this application is fixed by a positioning plate with a boss. The boss is extended into the front part of the flame tube and then fixed to the corresponding support plate. The rear end of the flame tube is fixed by a support plate, which is fixed in the test pipe. The main disadvantage of this device is that the front end of the flame tube is mainly fixed by a boss extending into the front edge of the tube, which has a mediocre fixing effect. At the same time, the rear end is fixed by a flange, which is a rigid fixation and does not conform to the actual assembly situation.

[0005] The prior art CN207439679U discloses a combustion chamber test equipment and a measuring pipe section thereof. The combustion tube in this application is fixed at both ends, and both ends are fixed with external support structures. Specifically, the content disclosed in the application includes a heat exchange pipe to ensure that the temperature of the experimental device will not be too high during the experiment, thereby extending the service life of the flange. As for the fixing structure of the flame tube, the front and rear ends of the flame tube are fixed with a support plate structure with a circular hole, and the support plate is fixed to the inner wall of the pipe of the test equipment. The fixing method of this device adopts a support method at the front and rear ends, and the parts being tested may be easily deformed. At the same time, there is a lack of disassembly modules, etc., and the disassembly convenience is not high.

[0006] The prior art CN103350357A discloses a positioning and clamping device for a gas turbine flame tube, which uses two front and rear support seats to support the flame tube. The support structure at the front end is slightly higher than the rear end. The front end is provided with an integral positioning plate with a boss on the positioning plate, which extends into the end face of the flame tube for fixation; the rear end is fixed with a structure with a crossbeam and a positioning block. Specifically: the fixing device as a whole comprises two supporting uprights, which are fixed on the base. A positioning plate with a boss is fixed on the left supporting upright, and the positioning plate has a raised step that extends into the front edge of the flame tube; the positioning plate has a bolt fixing structure, and a series of structures such as a crossbeam and a positioning block are provided on the right supporting plate to fix the rear end of the flame tube. However, the overall structure of the device is complex, and the fixing method is rigid fixing, and the flame tube is in an inclined state when fixed.

[0007] The above-mentioned clamping methods are all designed for stable clamping, and are not designed for clamping of the simulator flame tube in specific application scenarios. At the same time, there is no design to use an elastic structure to support the other end of the flame tube. In addition, the modal experiments for measuring the vibration parameters of the flame tube in the prior art are all aimed at the modal parameters of the parts under the free boundary state, and do not simulate the actual assembly state of the flame tube in the combustion chamber, that is, it is impossible to provide a modal test under constraint conditions, and thus it is impossible to obtain accurate modal parameters. The free boundary modal test will instead bring huge interference to subsequent structural modifications. Therefore, no solution for measuring the flame tube in the actual assembly state has been found in the prior art, and no fixture for the flame tube test under this test solution has been provided. In terms of fixing methods, snap fasteners and other fixing methods are mostly used, and the positioning method of an annular gap plus a fixed block is not used.

[0008] In view of the above technical problems, the present invention is specially introduced. Summary of the Invention

[0009] The main purpose of the present invention is to provide a fixture for fixing a flame tube when measuring modal parameters of a flame tube of a gas turbine combustion chamber under actual assembly conditions.

[0010] In order to achieve the above-mentioned purpose, the combustion chamber flame tube modal test fixture device of the present invention includes a test bench surface, a first clamping unit and a second clamping unit arranged on the test bench surface, and the first clamping unit and the second clamping unit are arranged along the same axis parallel to the test bench surface.

[0011] With this structure, the first clamping unit secures the first end of the liner, and the second clamping unit secures the second end. The axis of the fixing structure on the first clamping unit is the same as the axis of the fixing structure on the second clamping unit. The clamping structures of the two clamping units are identical to those in actual assembly, enabling the measurement of modal parameters of the liner in a gas turbine combustor under actual assembly conditions.

[0012] The present invention further improves upon the above-mentioned solution by providing a first clamping unit comprising a first support assembly and a stop assembly. The first support assembly is fixed to the test bench surface, forming an annular gap between the first support assembly and the stop assembly. The leading edge of the conical workpiece to be tested is fixed along the annular gap. This fixing method provides sufficient support for the conical structure and simulates the actual fixing method of a conical flame tube component in use.

[0013] The present invention further improves upon the above-described solution in that the stop assembly includes a flange and a sleeve, the flange and sleeve being coaxially fixedly arranged, the flange being detachably mounted on the first support assembly, and the sleeve and the first support assembly forming an annular gap. During use and testing, the flange can be secured to the support assembly using bolts or other means, facilitating removal of the tested component.

[0014] The present invention further improves the above solution in that: the first clamping unit also includes multiple fixing components, the fixing components are connected to the first supporting component, the conical workpiece to be measured has a fixing block, and the fixing components fix the fixing block on the first supporting component.

[0015] The present invention further improves the above solution in that: a plurality of fixing components are evenly fixed on the first supporting component.

[0016] The present invention is a further improvement to the above solution in that: a groove is provided on the fixing assembly on the side close to the conical workpiece to be measured, and the shape of the groove matches that of the fixing block.

[0017] The present invention further improves the above solution in that one of the multiple fixing components is located at the highest point of the front edge of the conical workpiece to be measured.

[0018] The present invention further improves the above-mentioned scheme in that: the second clamping unit includes a second support component and an elastic support component. The second support component is fixed on the test bench surface and is used to support the rear edge of the conical workpiece to be measured. The elastic support component is located between the second support component and the rear edge of the conical workpiece to be measured.

[0019] The present invention further improves the above solution in that the elastic support component is annular, is arranged in the circular hole of the second support component, and is coaxially arranged with the rear edge of the conical workpiece to be measured.

[0020] The present invention further improves the above solution in that at least one of the first clamping unit and the second clamping unit is detachably arranged on the test bench surface.

[0021] The application of the technical solution of the present invention achieves at least the following beneficial effects:

[0022] 1. The clamping method of the present invention's clamping device is consistent with the actual clamping method of a flame liner. Two clamping units are used to clamp the ends of the flame liner, with the first end secured by a ring and the second end secured by an elastic support assembly. This method simulates the state of the flame liner during actual assembly, and the clamping device can be used to measure the modal parameters of the gas turbine combustor flame liner under simulated assembly conditions.

[0023] 2. At least one of the first clamping unit and the second clamping unit of the present invention is detachably arranged on the test platform, which can facilitate the disassembly and assembly of the flame tube to be tested and is easy to operate.

[0024] 3. The fixing assembly on the first clamping unit of the present invention is in a detachable state. This structure can ensure that the flame tube is stably fixed on the clamping unit and can facilitate the replacement and adjustment of the flame tube.

[0025] 4. The annular gap formed between the first supporting assembly and the limiting assembly on the first clamping unit of the present invention can fully support the leading edge of the flame tube part to be measured, ensuring that the flame tube part to be measured has little or no deformation during clamping, and can measure relevant parameters more accurately.

[0026] 5. An elastic support member is provided between the second clamping unit of the present invention and the workpiece, which can completely restore the condition of the part in actual working conditions and obtain more accurate measurement of the modal parameters of the flame tube to correct and guide the finite element analysis, and obtain a finite element model and analysis method that is more consistent with the test results, thereby saving test costs and improving R&D efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 A schematic diagram of an overall test fixture device according to the present invention is shown; and

[0029] Figure 2 A cross-sectional view showing the overall test fixture assembly in the middle; and

[0030] Figure 3 Shown Figure 2 An enlarged view of section A is shown; and

[0031] Figure 4 Shown Figure 2 an enlarged view of part B as shown; and

[0032] Figure 5 Shown Figure 1 An enlarged view of section A is shown; and

[0033] Figure 6 Shows the disassembled view of the tail parts of the fixture.

[0034] The above drawings include the following reference numerals:

[0035] 1. First clamping unit; 2. Second clamping unit; 3. Test bench top; 4. Limit assembly; 5. First support assembly; 6. Conical workpiece; 7. Fixing block; 8. Leading edge; 9. Fixing assembly;

[0036] 10. Second support assembly;

[0037] 11. Elastic support assembly; 12. Trailing edge; 13. Sleeve; 14. Flange. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] The present invention is described in further detail below with reference to specific embodiments. These embodiments are not to be construed as limiting the scope of protection claimed by the present invention. The term "including" when used indicates the existence of a feature, but does not exclude the existence or addition of one or more other features; the terms "lateral", "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be construed as limiting the present invention; in addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance.

[0040] In this description, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0041] The combustion liner of a gas turbine combustion chamber is generally conical, indicated in the accompanying drawings as a conical workpiece 6. During testing, this workpiece requires a clamping structure to more accurately measure the modal parameters of the conical workpiece 6 when assembled into a specific product. The present invention provides a modal test fixture for a combustion liner, which can be used to clamp the combustion liner and test the modal parameters of the conical part.

[0042] like Figure 1-3As shown, a first clamping unit 1 and a second clamping unit 2 are fixed on the test bench surface 3, respectively, wherein the first clamping unit 1 is used to clamp and fix the leading edge 8 of the conical cylindrical workpiece 6, and the second clamping unit 2 is used to fix and clamp the trailing edge 12 of the conical cylindrical workpiece 6. The first clamping unit 1 and the second clamping unit 2 are configured on the same axis on the test bench surface 3. The purpose of stable fixation can be achieved by fixing the leading edge 8 and the trailing edge 12 of the conical cylindrical workpiece 6 respectively by the first clamping unit 1 and the second clamping unit 2. At the same time, the first clamping unit 1 and the second clamping unit 2 are configured on the same axis, which can fix the measured conical cylindrical workpiece 6 in a horizontal manner, and the measurement quality can be guaranteed, eliminating the variables introduced by other fixed angles when fixing by tilting and other methods, thereby better achieving the measurement purpose.

[0043] like Figure 2-Figure 3 As shown, the first clamping unit 1 includes a first support assembly 5, a stop assembly 4, and a fixing assembly 9. The first support assembly 5 is fixed to the test bench surface 3. The fixing method can be detachable or fixed using a common fixing method in the mechanical field. A circular through-hole is formed in the first support assembly 5. The diameter of the circular through-hole is the same as the outer diameter of the leading edge 8, ensuring that the outer diameter 8 can be accommodated in the circular hole.

[0044] The limiting assembly 4 is a cylindrical structure with a flange, including a sleeve 13 and a flange 14. The outer diameter of the sleeve 13 is not larger than the inner diameter of the leading edge 8 to ensure that the sleeve 13 can be inserted into the leading edge 8. When the limiting assembly 4 is installed on the first support assembly 5, the flange 14 is fixed to the side of the first support assembly 5. The fixing method can be bolted, or it can be welded, glued, etc. This fixing method can achieve easy disassembly of the limiting assembly 4, which is beneficial for disassembly and adjustment during the test and improves the measurement efficiency. The length of the sleeve 13 is longer than the thickness of the first support assembly 5, which can better support the leading edge 8 and ensure that the deformation of the conical workpiece 6 to be measured is small or there is no deformation. The circular ring formed by the sleeve 13 and the first support assembly 5 can fix the leading edge 8 from both the inside and the outside, so that the conical workpiece 6 is better fixed in the measuring room and the fixing effect is better.

[0045] The fixing component 9 is fixed on the edge of the circular hole of the first supporting component 5. There are at least two fixing components 9, and at least one fixing component 9 is at the top of the circular hole. This configuration can fix the flame tube to be measured at the top, thereby effectively preventing the flame tube to be measured from undergoing a large deformation of the cylinder due to gravity. When the fixing component 9 is at the top, the middle part of the conical workpiece 6 can sink due to gravity, thereby deforming, affecting the final measurement effect. When there are multiple fixing components 9, at least one is at the top, which can ensure the relative certainty of the arrangement of the fixing components 9, reduce the variable amount when measuring multiple sets of parameters or different conical workpieces 6, and thus facilitate the comparison of multiple sets of measurement data.

[0046] Furthermore, multiple fixing assemblies 9 can be evenly distributed around the edges of the circular hole in the first support assembly 5. This method provides a more stable clamping of the flame tube under test and prevents unnecessary vibration. Furthermore, the even distribution of multiple fixing assemblies 9 around the edges of the circular hole in the first support assembly 5 is consistent with the method used to secure the flame tube under actual working conditions, allowing for more accurate measurement of the modal parameters of the workpiece under actual working conditions.

[0047] like Figure 2 、 Figure 3 and Figure 5 As shown, the surface of the fixing assembly 9 that contacts the workpiece has a cavity, the shape of which matches the shape of the fixing block 7 of the flame tube of the workpiece to be tested. That is, the shape of the protrusion of the fixing block 7 is the same as the concave shape of the fixing assembly 9. This structure ensures that the fixing assembly 9 can better fix the fixing block 7, thereby better fixing the leading edge 8 of the flame tube to be tested, and making the flame tube and the first support assembly 5 more firmly fixed.

[0048] like Figure 1 、 Figure 2 and Figure 4 As shown, the second clamping unit 2 includes a second supporting assembly 10 and an elastic supporting assembly 11 , and the second clamping unit is fixed on the test bench surface 3 .

[0049] The second support assembly 10 is fixed to the test bench table 3. It has a circular hole in it. The diameter of the circular hole is the same as the outer diameter of the elastic support assembly 11. The trailing edge 12 of the conical workpiece 6 to be tested is fixed inside the elastic support assembly 11. This assembly method can relatively stably support the trailing edge 12 of the conical workpiece 6. At the same time, the elastic support assembly 11 is elastic, which facilitates installation when the workpiece is installed, preventing errors between the trailing edge 12 and the circular hole in the second support assembly 10, which can easily cause deformation of the trailing edge 12 when a rigid connection is used. This support method is consistent with the actual fixing method and can more accurately measure the modal parameters of the conical workpiece 6 in its actual assembled state.

[0050] The elastic support component 11 is in the shape of a flat ring, and its maximum outer diameter is the same as the circular hole on the second support component 10, and the smallest inner diameter of the elastic support component 11 is the same as the diameter of the trailing edge 12. At the same time, the axis of the elastic support component 11, the axis of the circular hole on the second support component 10, and the axis of the conical workpiece 6 to be measured coincide with each other. The elastic support component 11 can support the conical workpiece 6 to be measured in an elastic manner, and this support method is the same as the actual assembly method of the conical workpiece 6, so it is possible to measure the simulated parameters of the conical workpiece 6 in the actual assembly condition. The elastic support component 11 adopts the elastic sealing hula hoop commonly used in this field, or adopts other elastic components with elastic coefficients and structures similar to the elastic sealing hula hoop. At the same time, when the elastic structure used is quite different from the actual elastic component, it is necessary to consider the impact of the change of the structure on the measurement structure during the later data processing.

[0051] like Figure 1 As shown, at least one of the first clamping unit 1 and the second clamping unit 2 can be removably fixed to the test bench surface 3, thereby conveniently assembling and disassembling the flame tube to be tested. Disassembly can be achieved using bolts, clamps, adhesives, etc. If bolts are used for fixing, corresponding threaded holes are provided on the test bench surface 3.

[0052] In summary, from the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0053] 1. The clamping method of the present invention's clamping device is consistent with the actual clamping method of a flame liner. Two clamping units are used to clamp the ends of the flame liner, with the first end secured by a ring and the second end secured by an elastic support assembly. This method simulates the state of the flame liner during actual assembly, and the clamping device can be used to measure the modal parameters of the gas turbine combustor flame liner under simulated assembly conditions.

[0054] 2. At least one of the first clamping unit and the second clamping unit of the present invention is detachably arranged on the test platform, which can facilitate the disassembly and assembly of the flame tube to be tested and is easy to operate.

[0055] 3. The fixing assembly on the first clamping unit of the present invention is in a detachable state. This structure can ensure that the flame tube is stably fixed on the clamping unit and can facilitate the replacement and adjustment of the flame tube.

[0056] 4. The annular gap formed between the first supporting assembly and the limiting assembly on the first clamping unit of the present invention can fully support the leading edge of the flame tube part to be measured, ensuring that the flame tube part to be measured has little or no deformation during clamping, and can measure relevant parameters more accurately.

[0057] 5. An elastic support member is provided between the second clamping unit of the present invention and the workpiece, which can completely restore the condition of the part in actual working conditions and obtain more accurate measurement of the modal parameters of the flame tube to correct and guide the finite element analysis, and obtain a finite element model and analysis method that is more consistent with the test results, thereby saving test costs and improving R&D efficiency.

[0058] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A combustion chamber flame tube modal test fixture device, characterized by: The invention comprises a test bench surface (3), a first clamping unit (1) and a second clamping unit (2) arranged on the test bench surface (3), wherein the first clamping unit (1) and the second clamping unit (2) are arranged along the same axis parallel to the test bench surface (3); The first clamping unit (1) comprises a first supporting assembly (5) and a limiting assembly (4); the first supporting assembly (5) is fixed on the test bench surface (3); an annular gap is formed between the first supporting assembly (5) and the limiting assembly; and the leading edge (8) of the conical workpiece (6) to be tested is fixed along the annular gap; The second clamping unit (2) comprises a second supporting assembly (10) and an elastic supporting assembly (11), wherein the second supporting assembly (10) is fixed on the test bench table (3) and is used to support the rear edge (12) of the conical cylindrical workpiece (6) to be tested, and the elastic supporting assembly (11) is located between the second supporting assembly (10) and the rear edge (12); The elastic support component (11) is annular, and the elastic support component (11) is arranged in the circular hole of the second support component (10). The elastic support component and the rear edge (12) are coaxially arranged.

2. The combustion chamber flame liner modal test fixture device according to claim 1, characterized in that: The limiting assembly comprises a flange (14) and a sleeve (13), wherein the flange (14) and the sleeve (13) are coaxially fixedly arranged, and the flange (14) is detachably arranged on the first supporting assembly (5), and the sleeve (13) and the first supporting assembly (5) form the annular gap.

3. The combustion chamber flame liner modal test fixture device according to claim 1 or 2, characterized in that: The first clamping unit (1) further comprises a plurality of fixing assemblies (9), wherein the fixing assemblies (9) are connected to the first supporting assembly (5), and the conical cylindrical workpiece (6) to be measured has a fixing block (7), and the fixing assemblies (9) fix the fixing block (7) on the first supporting assembly (5).

4. The combustion chamber flame liner modal test fixture device according to claim 3, characterized in that: The plurality of fixing components (9) are evenly fixed on the first supporting component (5).

5. The combustion chamber flame liner modal test fixture device according to claim 4, characterized in that: The fixing assembly (9) is provided with a groove on the side close to the conical cylindrical workpiece (6) to be measured, and the groove matches the shape of the fixing block (7).

6. The combustion chamber flame liner modal test fixture device according to claim 5, characterized in that: One of the plurality of fixing assemblies (9) is located at the highest point of the front edge of the conical workpiece (6) to be measured.

7. The combustion chamber flame tube modal test fixture device according to claim 1, characterized in that : At least one of the first clamping unit (1) and the second clamping unit (2) is detachably arranged on the test bench surface (3).

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