A Combustion Chamber Nozzle Modal Testing Fixture Device

Abstract

This invention discloses a combustion chamber nozzle modal testing fixture device. The device includes a test platform (3), a first clamping unit (1), and a second clamping unit (2). The first clamping unit (1) and the second clamping unit (2) are disposed on the test platform (3). The device is characterized in that the first clamping unit (1) is provided with a cavity for accommodating the end (18) of the workpiece to be tested and a fuel supply assembly. This clamping device can stably support the workpiece to be tested, and the cavity can accommodate the protrusion of the product. Simultaneously, the clamping method is the same as the actual assembly method of the workpiece to be tested, thereby obtaining parameters of the finite element model that better match the test results, thus improving the accuracy of the finite element method calculation, thereby saving test costs and improving R&D efficiency.

Description

Technical Field

[0001] This invention relates to a fixture for modal testing of gas turbine combustor components, and more specifically, to a fixture required for a fixture for modal testing of nozzles in a gas turbine combustor. Background Technology

[0002] Combustion chamber components are affected by various excitation forces, such as combustion pulsation and overall engine vibration, which may lead to malfunctions during combustion chamber operation. Furthermore, under time-varying loads, if components vibrate, alternating stresses are generated. If the energy transmitted by the excitation force cannot be converted into kinetic energy or absorbed by damping, the components will continue to vibrate for a certain stress cycle coefficient, eventually leading to cracks or fracture and ultimately vibration failure. Therefore, understanding the vibration characteristics of the combustion chamber structure and verifying the rationality of its structural dynamics design are essential.

[0003] Modal analysis, also known as the experimental process of modal analysis or simply modal testing, is one of the methods 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, weaponry, shipbuilding, and nuclear industry, as well as civilian industries such as automobiles and construction. Modal testing equipment mainly includes fixtures, exciters, force sensors and acceleration sensors, data acquisition systems, and measurement systems. Among these, the fixture device is a crucial component of the modal testing equipment. A reasonable fixture design for the test piece is fundamental to modal testing. In existing modal testing technologies, the fixture device for the nozzle of a heavy-duty gas turbine combustion chamber is based on free boundary modal testing. Methods used to simulate free boundaries mainly include: rubber rope suspension, sponge pad support, airbag support, rubber pad support, air spring support, soft elastic support, or suspension.

[0004] In existing technologies, modal testing devices for heavy-duty gas turbine combustor nozzles provide free boundaries, simulating test specimens without any constraints on the ground. However, the actual assembly state of the nozzle at the combustor head is complex, involving the combustor end cap and shroud, and is situated within a constrained boundary with high stiffness. Therefore, free boundaries cannot simulate the actual assembly state of the nozzle at the combustor head, meaning they cannot provide modal testing under constrained conditions. Consequently, accurate modal parameters that closely resemble actual operating conditions cannot be obtained, and free boundary modal testing can significantly interfere with subsequent structural modifications. In actual engineering testing, the test object should be as close as possible to its actual operating state and boundary conditions to minimize testing errors.

[0005] Existing technology CN103592132B discloses a pressurized and visualized combustion test device for a gas turbine combustor. In this device, the nozzle is fixed to the inner cavity of the test apparatus via a flange and a support base. Specifically, the nozzle consists of three parts: a pipeline section, a nozzle body, and a nozzle tip. The nozzle body has a large flange, which is fixed to the test equipment. The nozzle tip extends directly into the inner cavity of the test equipment and is supported by a support frame. However, this document does not specify a cavity to accommodate the protruding parts, and its clamping method differs from the actual clamping method of the nozzle. Therefore, the core of this technical solution is stable fixation, and it does not focus on measuring the modal parameters of the parts.

[0006] Existing technology CN114354203A discloses an integrated performance testing device for a vortex generator and nozzle. The nozzle is fixed to the testing device using a flange, and the nozzle tip is fixed inside the test bench using a ring-shaped support structure. Specifically, the nozzle disclosed in this application is cylindrical in shape, with several fuel supply pipes at the top and a flange in the middle. The nozzle is fixed to the test body using bolts via this flange, and the nozzle tip is fixed to the product body via a mounting point. However, this application does not include a product cavity structure corresponding to the fuel lines of the nozzle. Furthermore, its measurement focuses on the fluid characteristics of the gas nozzle, rather than modal parameters.

[0007] Existing technology CN208872520U discloses a test bench for a multi-head test piece of a gas turbine combustor. In this test bench, three support structures are used to fix the nozzle in the inner cavity of the test device. The nozzle end has a fuel pipe, and the test device has a fuel pipe inlet and space to accommodate the fuel pipe. Specifically, in this application, the nozzle is tubular in shape, with a fuel pipe at the tail end. Both the fuel pipe and the nozzle are located inside the test device. The nozzle is fixed to the middle of the cavity using fixed support structures at the head, middle, and tail ends. The fuel pipe extends out of the cavity through a hole at the tail end. The technical solution disclosed in this patent is to accommodate the entire nozzle inside the test equipment, rather than setting up a clamping device that only accommodates part of the nozzle structure, and the support method uses three support structures.

[0008] In summary, current experimental setups lack fixtures specifically designed for measuring the modal parameters of gas turbine nozzles under constrained conditions. The usual approach is to measure these parameters using unconstrained methods. Furthermore, the nozzle clamping tools do not include cavities specifically designed to accommodate the nozzle's protruding structures.

[0009] In view of the above technical problems, this invention is hereby introduced. Summary of the Invention

[0010] The main objective of this invention is to provide a fixture for fixing the nozzle when measuring the modal parameters of the nozzle in a gas turbine combustion chamber under actual assembly conditions.

[0011] To achieve the above objectives, the present invention discloses a combustion chamber nozzle modal testing fixture device, which includes a test table, a first clamping unit, and a second clamping unit. The first clamping unit and the second clamping unit are disposed on the test table, and the first clamping unit is provided with a part cavity for accommodating the end of the workpiece to be tested and the fuel supply assembly.

[0012] A further improvement of the above solution in this invention is that the shape of the cavity of the part matches the shape of the protrusion of the workpiece to be tested.

[0013] A further improvement of the present invention to the above solution is that: the part cavity includes a first cavity, which is used to accommodate the end.

[0014] A further improvement of the present invention to the above solution is that the part cavity further includes a second cavity for accommodating the fuel supply assembly.

[0015] A further improvement of the above solution in this invention is that the second cavity includes a fuel flange cavity and a fuel pipeline cavity. The fuel flange cavity is used to accommodate the fuel flange of the fuel supply assembly, and the fuel pipeline cavity is used to accommodate the fuel pipeline of the fuel supply assembly. The fuel flange cavity and the fuel pipeline cavity are connected.

[0016] A further improvement of the above solution in this invention is that the first clamping unit includes a first support base, the first support base is fixed on the test table surface, and the part cavity is disposed on the first support base.

[0017] A further improvement of the present invention to the above solution is that the first clamping unit further includes a flange, which is used to fix the flange of the workpiece to be measured on the first support.

[0018] A further improvement of the above solution in this invention is that the flange has a through hole in the middle, which provides passage space for the end and fuel supply assembly.

[0019] A further improvement of the above solution in this invention is that the second clamping unit is fixedly connected to the test table surface.

[0020] A further improvement of the present invention to the above solution is that: the second clamping unit is provided with a support hole, which is used to support the tail of the workpiece to be tested.

[0021] A further improvement of the present invention to the above solution is that at least one of the first clamping unit and the second clamping unit is detachably connected to the test table surface.

[0022] By applying the technical solution of this invention, at least the following beneficial effects are achieved:

[0023] 1. The present invention provides a cavity in the clamping device to accommodate the protruding structure of the part, which can be adapted to the shape of the part, resulting in more accurate measurement results.

[0024] 2. The present invention uses two support structures to fix the part to be tested, which makes the clamping stability stronger.

[0025] 3. The clamping and fixing methods of the clamping structure are the same as those of the nozzle in actual assembly, which can better simulate the state of the nozzle in actual working conditions, thus making the modal parameter measurement more accurate and meeting the subsequent testing requirements.

[0026] 4. At least one of the support units of the present invention is detachably fixed on the test bench surface, which can be easily disassembled and improve test efficiency.

[0027] 5. The cavity in the support structure that accommodates the part being measured is divided into multiple cavities according to the protruding structure of the part, so as to better match the part being measured and make it more conducive to the accuracy of the measurement results.

[0028] 6. The flange structure in this application is exactly the same as the nozzle under test in actual working conditions, which not only facilitates disassembly, but also further improves measurement accuracy. Attached Figure Description

[0029] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0030] Figure 1 A schematic diagram of the overall test fixture device according to the present invention is shown; and

[0031] Figure 2 A breakdown diagram of the overall test fixture is shown; and

[0032] Figure 3 An enlarged view of the first clamping unit after partial disassembly is shown; and

[0033] Figure 4 A schematic diagram of the end of the nozzle under test is shown; and

[0034] Figure 5 An enlarged view of the second clamping unit after disassembly is shown.

[0035] The above figures include the following reference numerals:

[0036] 1. First clamping unit; 2. Second clamping unit; 3. Test table surface; 4. First support base; 5. Flange; 6. Fuel flange; 7. Fuel pipeline; 8. Flange; 9. Tail end; 10. Part cavity;

[0037] 11. Second cavity; 12. Fuel flange cavity; 13. Fuel pipeline cavity; 14. First cavity; 15. Through hole; 16. Fuel supply assembly; 17. Support hole; 18. End. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] The present invention will be further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention. The term "comprising" indicates the presence of a feature, but does not exclude the presence or addition of one or more other features. The terms "lateral," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the purpose of description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In this description, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0041] This embodiment relates to a combustion chamber nozzle modal testing fixture device. The device stably supports the workpiece to be tested through multiple clamping units, and the cavity on the clamping unit can accommodate the protrusion of the product. Moreover, its clamping structure is the same as the actual assembly method of the workpiece to be tested, thereby obtaining a finite element model and analysis method that is more consistent with the test results, improving the accuracy of the part parameters tested by the finite element method, thereby saving test costs and improving R&D efficiency.

[0042] like Figure 1-2As shown, the present invention relates to a fixture device for modal testing of gas turbine combustor nozzles. The device includes a test platform 3, a first clamping unit 1, and a second clamping unit 2. The first clamping unit 1 and the second clamping unit 2 are disposed on the test platform 3. The first clamping unit 1 is provided with a part cavity 10 for accommodating the end 18 of the workpiece to be tested and the fuel supply assembly 16. The use of two support structures, the first clamping unit 1 and the second clamping unit 2, to fix the workpiece to be tested provides stronger clamping stability and more accurate measurement results. Simultaneously, the first support base 4 has a part cavity 10, which can accommodate the protrusion of the workpiece to be tested. The opening of the part cavity 10 is larger than the protrusion of the workpiece, facilitating the entry and exit of the workpiece from the part cavity 10.

[0043] The shape of the cavity 10 matches the shape of the protrusion of the workpiece to be measured, and the distance between the wall of the cavity 10 and the workpiece to be measured is greater than zero. Therefore, it can be ensured that there is no mutual interference when testing the parameters of the workpiece, thereby improving the measurement accuracy. At the same time, the appropriate volume space of the cavity makes the structure of the first support 4 more compact, with better rigidity and stability, enabling higher accuracy when measuring the part to be measured.

[0044] like Figure 3 As shown, the part cavity 10 includes a first cavity 14, which is used to accommodate the end 18 of the workpiece to be measured. The distance between the end 18 of the workpiece to be measured and the first cavity 14 is greater than zero, so that there is no mutual interference when testing the workpiece parameters, thereby improving the measurement accuracy. The opening of the first cavity 14 is not smaller than the end 18 of the workpiece to be measured, so as to facilitate the entry and exit of the workpiece to be measured into the first cavity 14. The optional shape of the first cavity 14 can be a circular hole, a rectangular hole, etc., which is also beneficial for processing and manufacturing.

[0045] like Figure 2 , 3 As shown, the part cavity also includes a second cavity 11, which is used to accommodate the fuel supply assembly 16. The distance between the fuel supply assembly 16 of the workpiece under test and the second cavity 11 is greater than zero, so that there will be no mutual interference when testing the workpiece parameters, thereby improving the measurement accuracy.

[0046] The second cavity 11 includes a fuel flange cavity 12 and a fuel pipeline cavity 13. The fuel flange cavity 12 is used to accommodate the fuel flange 6 of the fuel supply assembly, and the fuel pipeline cavity 13 is used to accommodate the fuel pipeline 7 of the fuel supply assembly. The fuel flange cavity 12 and the fuel pipeline cavity 13 are connected. By setting the fuel flange cavity 12 and the fuel pipeline cavity 13, the cavities can be designed according to the specific shapes of the fuel flange 6 and the fuel pipeline 7. The shape of the cavity matches the actual shape and structure of the part, which can improve the rigidity of the first support seat 4 of the support structure of the same volume. This results in a larger difference between the natural vibration frequency of the first clamping unit 1 and the natural vibration frequency of the workpiece being measured, thus having a smaller impact on the measurement and calculation of the specific parameters of the workpiece being measured.

[0047] The first clamping unit 1 includes a first support base 4, which is fixed to the test table surface 3. The part cavity 10 is disposed on the first support base 4. The fixed position of the first support base 4 on the test table surface 3 matches the specific shape of the workpiece to be tested, ensuring that when the first clamping unit 1 fixes the workpiece to be tested, the distance between the clamped part and the test table surface 3 is greater than zero. Therefore, it is ensured that the workpiece to be tested and the vibration table surface 3 will not interfere with each other in the actual measurement chamber. The fixing methods of the first support base 4 and the test table surface 3 include, but are not limited to, fixing by bolts, welding, bonding, etc.

[0048] The first clamping unit 1 also includes a flange 5, which is used to fix the flange of the workpiece to be measured onto the first support 4. The flange 5 is located between the flange 8 of the workpiece to be measured and the first support 4; fixing structures such as bolts and clamps fix the flange 8 and the flange 5 to the side of the first support 4. This flange can be easily removed from the first clamping unit 1, and at the same time, it can increase the overall mass of the first clamping unit 1, thereby further increasing the difference between the vibration frequency of the first clamping unit 1 and the natural frequency of the workpiece to be measured.

[0049] like Figure 4 As shown, flange 5 has a through hole 15 in the middle, which provides passage space for end 18 and fuel supply assembly 16. The shape of through hole 15 needs to be larger than the maximum outer dimensions of end 18 and fuel supply assembly 16 to ensure that the protruding structure of the nozzle can pass smoothly through through hole 15 and enter the corresponding receiving cavity. Through hole 15 also allows for easy assembly and disassembly of parts.

[0050] like Figure 1 , 2As shown in Figure 5, the second clamping unit 2 is fixedly connected to the test table surface 3. The fixed position of the second clamping unit 2 and the test table surface 3 needs to match the position of the first clamping unit 1 and the specific shape of the workpiece to be tested; the fixing methods of the second clamping unit 2 and the test table surface 3 include, but are not limited to, bolting, welding, and bonding. The second clamping unit 2 ensures that the tail 9 of the part to be tested is stably fixed on the test table surface 3, thereby making the test results more accurate.

[0051] The second clamping unit 2 is equipped with a support hole 17, which is used to support the tail 9 of the workpiece to be measured. The shape of the support hole 17 matches the shape of the tail 9 of the workpiece to be measured. When fixing the workpiece to be measured, the tail 9 of the workpiece to be measured is placed into the support hole 17. The support hole 17 can be a circular hole. The support hole 17 and the tail 9 of the workpiece to be measured are configured coaxially to ensure that the contact surface between the support hole 17 and the tail 9 is large, which can provide more stable support and thus improve measurement accuracy. At the same time, the support hole 17, the tail 9 and the flange 5 are configured coaxially. The optional axis is kept horizontal, which can ensure that the part to be measured is in a horizontal state during measurement, thereby minimizing the impact on the measurement results and improving measurement efficiency and quality.

[0052] like Figure 2 As shown, at least one of the first clamping unit 1 and the second clamping unit 2 is detachably connected to the test table surface 3. This structure ensures that at least one of the first clamping unit 1 and the second clamping unit 2 can be removed and its position adjusted, ensuring that the testing device can adapt to different sizes of the parts to be tested and facilitates the assembly and disassembly of the parts to be tested.

[0053] In summary, the combustion chamber nozzle modal testing clamp has the following characteristics and effects:

[0054] 1. The present invention provides a cavity in the clamping device to accommodate the protruding structure of the part, which can be adapted to the shape of the part, resulting in more accurate measurement results. Furthermore, configuring the cavity according to the shape of the part reduces the proportion of voids in the support structure, thereby increasing the weight and rigidity of the support structure. This increases the difference between the natural frequency of the support structure and the natural frequency of the workpiece being measured, leading to more accurate measurement results.

[0055] 2. This invention employs two support structures to fix the part under test, resulting in stronger clamping stability. At least one support unit is detachably fixed to the test platform, facilitating easy disassembly and improving testing efficiency. The support structure ensures that the axis of the part under test is horizontal, eliminating variables in the measurement process and further improving testing efficiency.

[0056] 3. The clamping structure is fixed in the same way as the nozzle is actually assembled, which can better simulate the state of the nozzle in actual working conditions, so the results of modal parameter measurement are more accurate and meet the subsequent testing requirements.

[0057] 4. The cavity in the support structure that accommodates the part being measured is divided into multiple cavities according to the protruding structure of the part, so as to better match the part being measured and make it more conducive to the accuracy of the measurement results.

[0058] 5. The flange structure in this application is exactly the same as the nozzle under test under actual working conditions, which not only facilitates disassembly but also further improves measurement accuracy. In addition, the opening of the cavity is larger than the protruding structure of the part under test, ensuring that the protrusion of the part under test is placed inside the cavity.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A combustion chamber nozzle modal testing fixture device, the device comprising a test platform (3), a first clamping unit (1), and a second clamping unit (2), wherein the first clamping unit (1) and the second clamping unit (2) are disposed on the test platform (3), characterized in that: The first clamping unit (1) is provided with a part cavity (10) for accommodating the end (18) of the workpiece to be tested and the fuel supply assembly (16). The first clamping unit includes a first support base (4), which is fixed on the test table surface (3), and the part cavity (10) is disposed on the first support base (4); The first clamping unit also includes a flange (5), which is used to fix the flange of the workpiece to be tested on the first support base (4).

2. The combustion chamber nozzle modal testing fixture device according to claim 1, characterized in that: The shape of the cavity (10) of the part matches the shape of the protrusion of the workpiece to be tested.

3. The combustion chamber nozzle modal testing fixture device according to claim 1, characterized in that: The part cavity (10) includes a first cavity (14) for accommodating the end (18).

4. The combustion chamber nozzle modal testing fixture device according to claim 3, characterized in that: The component cavity also includes a second cavity (11) for accommodating the fuel supply assembly (16).

5. The combustion chamber nozzle modal testing fixture device according to claim 4, characterized in that: The second cavity (11) includes a fuel flange cavity (12) and a fuel pipeline cavity (13). The fuel flange cavity (12) is used to accommodate the fuel flange (6) of the fuel supply assembly, and the fuel pipeline cavity (13) is used to accommodate the fuel pipeline (7) of the fuel supply assembly. The fuel flange cavity (12) and the fuel pipeline cavity (13) are connected.

6. The combustion chamber nozzle modal testing fixture device according to claim 5, characterized in that: The flange (5) has a through hole (15) in the middle, which provides passage space for the fuel supply assembly (16) at the end (18).

7. The combustion chamber nozzle modal testing fixture device according to claim 1, characterized in that: The second clamping unit (2) is fixedly connected to the test table surface (3).

8. The combustion chamber nozzle modal testing fixture device according to claim 7, characterized in that: The second clamping unit (2) is provided with a support hole (17), which is used to support the tail (9) of the workpiece to be tested.

9. The combustion chamber nozzle modal testing 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 connected to the test table surface (3).

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