An ultrasonic detection device and method for the root slot of a gas turbine compressor impeller

Abstract

The present invention discloses an ultrasonic detection device and method for the root groove of a gas turbine compressor impeller, which includes a fixed arm, a rotating arm, and a cantilever connecting the rotating arm and a probe fixture. The fixed arm, its clamping claws and tightening device fix the detection tooling on the root groove of the compressor impeller; the connecting bolt enables the fixed arm and the rotating arm to rotate around its center; the rotating arm is Z-shaped and is sleeved with a vernier caliper for measuring the distance from the ultrasonic probe to the center of the connecting bolt; the upper end of the cantilever is fixed to the vernier caliper, and the lower end is connected to the probe fixture; the probe fixture fixes the ultrasonic probe through the screw holes on both sides. The present invention stably couples the ultrasonic probe to the surface of the root groove of the compressor impeller, enabling the ultrasonic probe to perform stable and reliable scanning; determines the distance range during the scanning of the ultrasonic probe through the distance and angle measurement functions of the detection tooling, providing a basis for the formulation of the detection process; and realizes the precise quantification of the crack size through the accurate measurement of the position and swing angle of the ultrasonic probe.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic detection, and relates to a device and method for ultrasonic detection of blade root grooves of a gas turbine compressor impeller. Background Art

[0002] The compressor moving blades are the main components of the compressor that do work on the gas turbine inlet gas. As a rotating machine, it needs to withstand the combined effects of centrifugal stress, airflow impact force, vibration stress and other loads during operation. The compressor moving blades and the compressor rotor are matched through the compressor impeller blade root groove. As the key to transmitting the compressor rotor torque to the compressor moving blades, the compressor impeller blade root groove not only bears the same or greater load, but also has a more severe working environment due to corrosion, fretting wear, etc., so the inspection of the health status of the compressor impeller blade root groove is particularly important to ensure the safe and stable operation of the gas turbine.

[0003] During the start-up and shutdown process of the gas turbine, the stress at the acute angles of the front end (upstream side) and rear end (downstream side) of the compressor impeller blade root groove is the largest. After a certain number of start-up and shutdown cycles, cracks may appear at the acute angle at the bottom of the compressor impeller blade root groove. Cracks generally extend in two directions, one is to extend radially along the front and rear surfaces of the rim toward the center of the compressor rotor, and the other is to extend forward or backward along the length direction (axial direction) of the blade root groove.

[0004] At present, the nondestructive testing technology for cracks in the root groove of gas turbine compressor impellers is mainly phased array ultrasonic testing technology. In actual testing, it is necessary not only to promptly detect cracks that may exist at the sharp angle of the root groove, but also to quantitatively evaluate the size of the cracks to provide test data for the safety assessment of the compressor impeller. Based on this, designing and processing a testing tool that can realize accurate scanning and accurate positioning of the ultrasonic probe is of great significance to improving the detection efficiency and quantitative accuracy. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art and to provide a gas turbine compressor impeller blade root groove ultrasonic detection device and method to achieve accurate scanning and positioning of the ultrasonic probe, thereby improving the compressor impeller blade root groove crack detection efficiency and quantitative accuracy.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A gas turbine compressor impeller blade root groove ultrasonic detection device, comprising:

[0008] A fixed arm, wherein claws are arranged at both ends of the fixed arm, and the fixed arm is buckled on the axial end surface of the compressor impeller blade root groove through the claws at both ends;

[0009] A rotating arm, the rotating arm includes two transverse connecting arms and a longitudinal connecting arm. One end of the first transverse connecting arm is hinged to one end of the fixed arm, the other end of the first transverse connecting arm is fixedly connected to the bottom end of the longitudinal connecting arm, and the top end of the longitudinal connecting arm is fixedly connected to one end of the second transverse connecting arm;

[0010] A probe fixture, the inner side of the probe fixture is used to fix the probe, the top is connected to the bottom end of the cantilever, and a vernier scale is fixedly connected to the top end of the cantilever. The vernier scale is slidably sleeved on the second transverse connecting arm.

[0011] A further improvement of the present invention lies in:

[0012] The fixed arm includes two sections, and the two sections are connected by a telescopic tightening device for fixing the fixed arm on the compressor impeller.

[0013] The tightening device is tightened by means of a screw press.

[0014] The angle of the pawl is the same as the inclination angle of the axial end face of the root groove of the compressor impeller, and an anti-slip rubber sleeve is provided on the inner side.

[0015] The first transverse connecting arm of the fixed arm and the rotating arm is hinged by a connecting bolt, and both the fixed arm and the rotating arm can rotate around the center of the connecting bolt.

[0016] The lower end of the connecting bolt is higher than the lower surface of the fixed arm.

[0017] Screw holes are respectively provided on both sides of the probe fixture.

[0018] A rotating arm scale with a minimum scale of 1.0 mm is engraved on the rotating arm, and the zero point of the rotating arm scale is located at the center of the connecting bolt; a vernier scale with a minimum scale of 0.9 mm is engraved on the vernier scale; a fixed arm and rotating arm included angle scale for calibrating the included angle between the fixed arm and the rotating arm can be provided on the fixed arm; a cantilever angle scale with a minimum scale of 9° is engraved on the cantilever; a probe fixture angle scale with a minimum scale of 10° is engraved on the probe fixture.

[0019] An ultrasonic detection method for the root groove of a compressor impeller of a gas turbine includes the following steps:

[0020] Fix the ultrasonic probe on the probe fixture through the screw hole. During the detection process, the ultrasonic probe moves back and forth along the rotating arm. The fixed arm makes the ultrasonic probe coupled to the upper surface of the root groove of the compressor impeller during the forward and backward scanning process, and at the same time records the scanning position and range and the swing angle of the probe during the scanning process; the scanning position and range are determined by the length L measured by the vernier scale on the rotating arm and the included angle θ between the rotating arm and the fixed arm, and the swing angle is determined by the probe fixture angle scale and the cantilever angle scale of the cantilever;

[0021] When quantifying the crack size in the root slot of the compressor impeller, move the ultrasonic probe back and forth to find the highest wave of the crack, and record the position (L, θ) of the probe at this time. Then, scan the ultrasonic probe along the direction perpendicular to the length of the probe, keep the swing angle of the ultrasonic probe unchanged, and find the probe positions (L1, θ1) and (L2, θ2) when the echo amplitude decreases by 6 dB respectively. At this time, the crack length L = L1 - L2.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] In the present invention, the ultrasonic probe is stably coupled to the surface of the root slot of the compressor impeller, enabling the ultrasonic probe to scan stably and reliably; the distance range during the scanning of the ultrasonic probe is determined through the distance and angle measurement functions of the detection tooling, providing a basis for formulating the detection process; and through the accurate measurement of the position and swing angle of the ultrasonic probe, the precise quantification of the crack size is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0025] Figure 1 is a schematic structural diagram of the present invention;

[0026] Figure 2 is a schematic diagram of the scale of the rotating arm of the present invention;

[0027] Figure 3 is a schematic diagram of the scale of the cantilever angle of the invention.

[0028] Among them, 1 - fixed arm, 2 - pawl, 3 - tightening device, 4 - connecting bolt, 5 - rotating arm, 6 - vernier scale, 7 - cantilever, 8 - probe fixture, 9 - screw hole, 10 - scale of the rotating arm, 11 - scale of the vernier scale, 12 - scale of the included angle between the fixed arm and the rotating arm, 13 - scale of the cantilever angle, 14 - scale of the probe fixture angle. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0031] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0032] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is customarily placed during use, it is 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 thus should not be construed as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0033] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0034] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "coupled" are 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0035] The present invention will be further described in detail below with reference to the accompanying drawings:

[0036] See Figures 1 - 3 , the ultrasonic detection device for the root slot of the compressor impeller of the gas turbine of the present invention includes a fixed arm 1, a pawl 2, a tightening device 3, a connecting bolt 4 for the fixed arm and the rotating arm, a rotating arm 5, a vernier scale 6 on the rotating arm, a cantilever 7 connecting the rotating arm and the probe fixture, and a probe fixture 8.

[0037] The fixed arm 1 is the key to fixing the detection device to the root slot of the compressor impeller. The latch 2 is buckled on the axial end face of the root slot of the compressor impeller, and the latch 2 is tightened by the tightening device 3. The connecting bolt 4 connects the fixed arm 1 and the rotating arm 5, enabling the fixed arm 1 and the rotating arm 5 to rotate around the center of the connecting bolt 4. The rotating arm 5 is Z-shaped and is used to accommodate the probe in the vertical direction. The vernier 6 is sleeved on the rotating arm 5 and can slide along the rotating arm 5, and is used to measure the distance between the probe and the center of the connecting bolt 4. The upper end of the cantilever 7 is fixed to the vernier 6, and the lower end is connected to the probe fixture 8. The probe fixture 8 is used to fix the ultrasonic probe, and there is 1 screw hole 9 on each of the two side faces.

[0038] The latch 2 has the same inclination angle as the axial end face of the root slot of the compressor impeller, and there is a rubber sleeve on the inner side of the latch 2 to prevent the tooling from sliding.

[0039] The fixed arm 1 consists of two sections, and there is a telescopic tightening device 3 between the two sections to change the length of the fixed arm 1, which is used to fix the detection device on the compressor impeller.

[0040] The tightening device 3 on the fixed arm 1 is tightened by the method of screwing.

[0041] The lower end of the connecting bolt 4 does not extend beyond the lower surface of the fixed arm 1 to prevent the detection device from having a gap with the upper surface of the impeller, resulting in unstable fixing of the tooling.

[0042] There is a rotating arm scale 10 with a minimum division of 1.0 mm engraved on the rotating arm 5, and the zero point of the rotating arm scale 10 is at the center of the connecting bolt 4.

[0043] There is a vernier 6 sleeved on the rotating arm 5, and there is a vernier scale 11 with a minimum division of 0.9 mm engraved on the vernier 6. Using the principle of dislocation magnification, a measurement accuracy of 0.1 mm is achieved.

[0044] The conventional method for measuring the angle between the fixed arm 1 and the rotating arm 5 is to set a protractor between them for measurement. Considering the actual application process, the detection device should not be too complex to prevent too many parts from falling into the compressor cylinder during on-site detection. A method of calibrating the angle between the fixed arm 1 and the rotating arm 5 and marking the corresponding scale 12 on the fixed arm 1 is proposed to measure the angle between the fixed arm 1 and the rotating arm 5.

[0045] There is a cantilever angle scale 13 with a minimum division of 9° engraved on the cantilever 7, and at the same time, there is a probe fixture angle scale 14 with a minimum division of 10° engraved on the probe fixture 8. Also using the principle of dislocation magnification, a measurement accuracy of at least 1° is achieved.

[0046] The inner surface of the screw hole 9 on the left and right side faces of the probe fixture 8 is machined with threads, and the probe can be fixed with screws through the screw hole 9.

[0047] Reference Figures 1 - 3 , the present invention will be further described as follows:

[0048] The ultrasonic probe is fixed on the probe fixture 8 through the screw hole 9. During the detection process, the ultrasonic probe moves back and forth along the rotating arm 5. The detection device ensures that the ultrasonic probe is stably coupled to the upper surface of the root slot of the compressor impeller during the forward and backward scanning process. At the same time, the scanning position, range, swing angle, etc. of the probe during the scanning process can be recorded. The scanning position and range are jointly determined by the length L measured by the vernier caliper 6 on the rotating arm 5 and the included angle θ between the rotating arm 5 and the fixed arm 1. The swing angle is read out through the probe fixture angle scale 14 and the cantilever angle scale 13 of the cantilever 7.

[0049] When quantifying the crack size of the root slot of the compressor impeller, move the ultrasonic probe back and forth to find the highest wave of the crack, and record the position (L, θ) of the probe at this time. Scan the ultrasonic probe along the direction perpendicular to the length of the probe, keep the swing angle of the ultrasonic probe unchanged, and find the probe positions (L1, θ1) and (L2, θ2) when the echo amplitude decreases by 6 dB respectively. At this time, the crack length L = L1 - L2 (take the positive value).

[0050] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An ultrasonic detection device for the root groove of a gas turbine compressor impeller, characterized in that, Comprising: A fixed arm (1), with catch claws (2) provided at both ends of the fixed arm (1). The fixed arm (1) is buckled on the axial end face of the root groove of the compressor impeller through the catch claws (2) at both its ends; the fixed arm (1) includes two sections, and the two sections are connected by a telescopic tightening device (3) for fixing the fixed arm (1) on the compressor impeller. A rotating arm (5), the rotating arm (5) includes two transverse connecting arms and one longitudinal connecting arm. One end of the first transverse connecting arm is hinged to one end of the fixed arm (1), the other end of the first transverse connecting arm is fixedly connected to the bottom end of the longitudinal connecting arm, and the top end of the longitudinal connecting arm is fixedly connected to one end of the second transverse connecting arm. A probe clamp (8), the inner side of the probe clamp (8) is used for fixing the probe, the top is connected to the bottom end of the cantilever (7), and the top end of the cantilever (7) is fixedly connected with a vernier scale (6). The vernier scale (6) is slidably sleeved on the second transverse connecting arm; screw holes (9) are respectively provided on both sides of the probe clamp (8). A rotating arm scale (10) with a minimum scale of 1.0 mm is engraved on the rotating arm (5), and the zero point of the rotating arm scale (10) is located at the center of the connecting bolt (4); a vernier scale (11) with a minimum scale of 0.9 mm is engraved on the vernier scale (6); there may be a fixed arm and rotating arm included angle scale (12) on the fixed arm (1) for calibrating the included angle between the fixed arm (1) and the rotating arm (5); a cantilever angle scale (13) with a minimum scale of 9° is engraved on the cantilever (7); a probe clamp angle scale (14) with a minimum scale of 10° is engraved on the probe clamp (8).

2. The ultrasonic detection device for the root groove of a gas turbine compressor impeller according to claim 1, characterized in that, The tightening device (3) is tightened by means of screw pressing.

3. The ultrasonic detection device for the root groove of a gas turbine compressor impeller according to claim 1 or 2, characterized in that, The catch claws (2) have the same inclination angle as the axial end face of the root groove of the compressor impeller, and an anti-slip rubber sleeve is provided on the inner side.

4. The ultrasonic detection device for the root groove of a gas turbine compressor impeller according to claim 1, characterized in that, The first transverse connecting arm of the fixed arm (1) and the rotating arm (5) is hinged by a connecting bolt, and both the fixed arm (1) and the rotating arm (5) can rotate around the center of the connecting bolt (4).

5. The ultrasonic detection device for the root groove of a gas turbine compressor impeller according to claim 4, characterized in that, The lower end of the connecting bolt (4) is higher than the lower surface of the fixed arm (1).

6. An ultrasonic detection method for the root groove of a gas turbine compressor impeller using the device according to any one of claims 1-5, characterized in that, Including the following steps: Fix the ultrasonic probe on the probe fixture (8) through the screw hole (9). During the detection process, the ultrasonic probe moves back and forth along the rotating arm (5). The fixed arm (1) couples the ultrasonic probe to the upper surface of the root groove of the compressor impeller during the forward and backward scanning process. At the same time, record the scanning position, range, and swing angle of the probe during the scanning process; the scanning position and range are measured by the length measured by the vernier caliper (6) on the rotating arm (5). L , the included angle between the rotating arm (5) and the fixed arm (1) θ is determined, and the swing angle is determined by the probe fixture angle scale (14) and the cantilever angle scale (13) of the cantilever (7); When quantifying the crack size in the root slot of a compressor impeller, move the ultrasonic probe back and forth to find the highest wave of the crack, and record the position of the probe at this time ( L , θ ). Then, scan the ultrasonic probe along the direction perpendicular to the length of the probe, keeping the swing angle of the ultrasonic probe unchanged, and find the positions of the probe when the echo amplitude decreases by 6 dB respectively ( L 1, θ 1) and ( L 2, θ 2). At this time, the crack length L = L 1- L 2.

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