A method and device for repairing the tenon groove of annular blades of a compressor casing

Abstract

The present invention provides a method for repairing the annular blade tenon groove of a compressor casing, the repair method comprising the following steps: S1: judging whether the contour of the annular tenon groove of the compressor casing exceeds a threshold value, if it exceeds the threshold value, proceeding to S2, if it does not exceed the threshold value, no repair is required; S2: processing the tenon groove working surface, fillet and tenon groove bottom surface, so that the three surface contour thicknesses of the tenon groove are the same; S3: selecting a tenon groove gasket with the same thickness as the surface contour thickness; S4: before assembling the blade, first put the tenon groove gasket obtained in S3 into the corresponding tenon groove out-of-tolerance side, and then install the corresponding stator blade. The repair method is easier to implement, can repair any out-of-tolerance size of the tenon groove, is not affected by factors such as bonding force, and does not require heating during the repair process, will not cause additional deformation of the casing, is applicable to any processing stage, and does not need to consider whether the casing still has margin; the method has good versatility, can effectively reduce the scrapping of the casing, and reduce processing and maintenance costs.

Description

Technical Field

[0001] The invention belongs to the technical field of gas turbine component repair, and in particular relates to a method and a device for repairing the tenon groove of an annular blade of a compressor casing. Background Art

[0002] There are two types of gas turbine compressor stator blades, one is an adjustable stator blade with a journal, and the other is a non-adjustable stator blade with a "T"-shaped tenon. Adjustable stator blades are generally fixed in the circular mounting hole of the compressor casing with nuts. Non-adjustable stator blades are installed in the annular T-shaped tenon groove of the compressor casing. In order to reduce the vibration of the blades when the engine is running, the tenon and tenon groove clearance should not be too large or too small, which requires the tenon groove to have a high processing accuracy.

[0003] In the actual processing process, due to factors such as tool wear and part deformation, there is a situation where the actual contour of the casing tenon groove is larger than the theoretical contour. In this case, people usually choose to give in and accept it. In serious cases, the entire casing will be scrapped directly. The process of processing the tenon groove is generally ranked later in the casing processing. If the entire casing is directly scrapped because the tenon groove is out of tolerance, it will cause great waste. However, if it is used directly without treatment, it may cause problems such as excessive engine vibration and accelerated blade wear in the future.

[0004] In addition, after the gas turbine has been working for a long time, due to the micro-wear between the blade tenon and the tenon groove, the tenon groove size may also become larger and out of tolerance. If it is not repaired in time, it will also lead to a decrease in compressor performance and a reduction in the life of parts such as blades. However, due to the complex manufacturing process and high cost of the gas turbine compressor casing, if a new compressor casing is directly replaced, the maintenance cost will increase significantly.

[0005] Therefore, the use of targeted repair methods and devices to repair the casing tenon and groove is an effective way to reduce scrapping and reduce the operating and maintenance costs of gas turbines. In the prior art, thermal spraying or surfacing is generally used to melt metal powder on the surface of the tenon and groove, and then re-machine it to the correct size, but this method has the following disadvantages: 1. After exceeding a certain thickness, the bonding force will drop significantly, and it is easy to fall off during re-machining; 2. If the spraying or welding temperature is high, it may also cause deformation of the casing. 3. The size of the tenon and groove is small, and it is difficult to implement spraying or welding. If the oversized tenon and groove are not handled, but the blade tenon and tenon and groove are enlarged. It will result in 1. The assembled blades lose interchangeability, and 2. The blades of one part number will have many specifications, which is economical and inconvenient for unified management. Summary of the invention

[0006] In order to solve the above-mentioned problem, the object of the present invention is to provide a method and a device for repairing the tenon groove of annular blades of a compressor casing.

[0007] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is as follows: a method for repairing the tenon groove of annular blades of a compressor casing is provided, and the repair method comprises the following steps:

[0008] S1: Determine whether the contour of the compressor casing annular tenon groove exceeds the threshold. If so, proceed to S2. If not, no repair is required.

[0009] S2: Process the working surface, fillet and bottom surface of the mortise and tenon groove so that the contour thickness of the three surfaces of the mortise and tenon groove is the same;

[0010] S3: Select the tongue and groove gasket with the same thickness as the surface profile;

[0011] S4: Before assembling the blades, place the tongue and groove gasket obtained in S3 into the side of the corresponding tongue and groove that exceeds the tolerance, and then install the corresponding stator blades.

[0012] The method for repairing the mortise and tenon of annular blades of a compressor casing provided by the present invention also has the characteristic that the mortise and tenon gaskets are spare gaskets of multiple thicknesses processed in advance.

[0013] The compressor casing annular blade tenon-groove repair method provided by the present invention also has the characteristic that the thickness difference of the plurality of spare gaskets is 0.02 mm.

[0014] Another object of the present invention is to provide a compressor casing annular blade tenon groove repair device, which is used to perform the repair method as described in any one of claims 1-3, including a left-side tenon groove gasket and a right-side tenon groove gasket corresponding to the compressor casing annular blade tenon groove.

[0015] The compressor casing annular blade tenon groove repair device provided by the present invention also has the feature that the structure and material of the left tenon groove gasket are the same as those of the right tenon groove gasket.

[0016] The compressor casing annular blade tenon groove repair device provided by the present invention also has the following characteristics: the left tenon groove gasket structure is a V-shaped cross-section metal half ring,

[0017] The V-shaped outer contour coincides with the inner side of the left working area of ​​the mortise, and the V-shaped inner contour is obtained by the outer contour along the normal offset thickness A.

[0018] The offset thickness A is the same as the out-of-tolerance dimension of the left mortise profile.

[0019] The compressor casing annular blade tenon groove repair device provided by the present invention also has the characteristic that the material of the left tenon groove gasket is a high-temperature alloy with a hardness greater than 42HRC.

[0020] The compressor casing annular blade tenon groove repair device provided by the present invention also has the feature that after the left tenon groove gasket is processed, the parameters of the left tenon groove gasket are marked on the surface.

[0021] Beneficial effects:

[0022] The compressor casing annular blade tenon groove repair method provided by the present invention is easier to implement than existing thermal spraying, surfacing welding, etc., and can repair tenons of any out-of-tolerance size, is not affected by factors such as bonding force, and does not require heating during the repair process, and will not cause additional deformation of the casing. Therefore, it is suitable for any processing stage without considering whether there is still margin in the casing; the method has good versatility and is suitable for repairing any annular blade tenon groove on the casing, which can effectively reduce casing scrapping and reduce processing and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 The compressor casing annular blade tenon groove repair method provided by the embodiment of the present invention provides a casing dovetail type annular tenon groove structure after repair;

[0025] Figure 2 A schematic diagram of the structure of the compressor tenon groove provided by an embodiment of the present invention;

[0026] Figure 3 A schematic structural diagram of a tongue and groove gasket provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and the accompanying drawings specifically illustrate the compressor casing annular blade tenon groove repair method and repair device provided by the present invention.

[0028] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the 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 should not be understood as a limitation on the invention.

[0029] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0030] 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 an indirect connection 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 invention can be understood according to specific circumstances.

[0031] like Figure 1-2 As shown, the gas turbine compressor casing 1 usually adopts a split structure, that is, it is divided into two halves along the circumference of 0°-180°, and is made of metal materials first forged or forged and then machined. In order to reduce the weight of the gas turbine, the casing is usually made into a thin-walled structure with a minimum wall thickness of about 2mm. The center of rotation of the casing is also the rotation axis of the gas turbine. The annular tenon 2 processed on the inner wall of the casing is used to install the stator blades.

[0032] The annular dovetail tenon structure on the receiver can be roughly divided into several parts, the left working surface 2-1, the left fillet 2-2, the left bottom surface 2-3, the right working surface 2-4, the right chamfer 2-5, the right bottom surface 2-6, and the tenon rotation centerline 4. The left working surface 2-1 and the right working surface 2-4 are the contact and matching surfaces between the tenon and the tenon. Under normal circumstances, there is a certain gap between the remaining surfaces and the tenon, and the gap is about 0.1. When designing the tenon, the tenon size is usually constrained in the form of theoretical contour plus surface contour. For example, the surface contour is 0.1, which means that the normal distance between the actual contour and the theoretical contour does not exceed ±0.05. If the distance is positive, the actual contour is considered to be larger than the theoretical contour, and if the distance is negative, the actual contour is considered to be smaller than the theoretical contour. If the actual contour is too small, the tenon can also be made to reach the qualified size by removing material, so it is not within the scope of the tenon repair discussion. This repair method only considers the situation where the actual contour is larger than the theoretical contour and exceeds the surface contour required by the design. As can be seen from the figure, if the contour of the left working surface 2-1 or the right working surface 2-4 of the mortise is larger than the theoretical contour, it will not only cause the gap between the blade tenon and the mortise to be too large, but also cause the blade to deviate from the designed position.

[0033] Therefore, an embodiment of the present invention provides a method for repairing a compressor casing annular blade tenon groove, the repair method comprising the following steps:

[0034] S1: Determine whether the contour of the compressor casing annular tenon groove exceeds the threshold. If so, proceed to S2. If not, no repair is required.

[0035] S2: Process the working surface, fillet and bottom surface of the mortise and tenon groove so that the contour thickness of the three surfaces of the mortise and tenon groove is the same;

[0036] S3: Select the tongue and groove gasket with the same thickness as the surface profile;

[0037] S4: Before assembling the blades, place the tongue and groove gasket obtained in S3 into the side of the corresponding tongue and groove that exceeds the tolerance, and then install the corresponding stator blades.

[0038] In some embodiments, assuming that the tolerance is within 0.05, if the actual surface profile minus the designed maximum profile ≤ 0.05, the tenon groove is not repaired. When the tolerance is greater than 0.05, the tenon groove working surface, fillet, and tenon groove bottom surface are processed again until the three surface profiles are the actual surface profiles, and then the tenon groove gasket with the same thickness as the surface profile is processed. Before assembling the blade, the tenon groove gasket is placed on the side of the corresponding tenon groove with tolerance, and then the corresponding stator blade is installed.

[0039] In some embodiments, for the convenience of repair, the tongue and groove gasket is a spare gasket of multiple thicknesses processed in advance. The thickness of the gasket ranges from 0.1mm to 0.2mm. When repairing, the corresponding tongue and groove gasket can be directly selected.

[0040] In some embodiments, the thickness difference between the plurality of backup gaskets is 0.02 mm.

[0041] In some embodiments, Figure 3 As shown, a compressor casing annular blade tenon groove repair device is provided, the device is used to perform any of the aforementioned repair methods, including a left tenon groove gasket 3-1 and a right tenon groove gasket 3-2 corresponding to the compressor casing annular blade tenon groove.

[0042] In some embodiments, the structure and material of the left tongue and groove gasket 3 - 1 are the same as those of the right tongue and groove gasket 3 - 2 .

[0043] In some embodiments, the left tongue-and-groove gasket structure is a V-shaped metal half ring.

[0044] The V-shaped outer contour coincides with the inner side surface of the left working area of ​​the mortise, that is, the left working surface 2-1, the left working fillet 2-2 and the left bottom surface 2-3 coincide. The V-shaped inner contour is obtained by the outer contour along the normal offset thickness A.

[0045] The offset thickness A is the same as the out-of-tolerance dimension of the left mortise profile.

[0046] In addition, in order to ensure that the left tongue and groove gasket does not interfere with the blade after being added, the width of the left tongue and groove gasket is smaller than the width B of the left tongue and groove itself.

[0047] In some embodiments, it is assumed that the actual left-side mortise contour is +0.2, and the designed contour is 0.1 (ie, ±0.05), that is, the contour exceeds the tolerance by +0.15, and the offset thickness A is 0.15.

[0048] In some embodiments, the left tongue and groove gasket is made of a high temperature alloy with a hardness greater than 42HRC, and can be formed by sheet metal or by forging machining.

[0049] In some embodiments, after the left tongue and groove gasket is processed, the parameters of the left tongue and groove gasket are printed on the surface. The parameters of the tongue and groove gasket include but are not limited to the level of blade tongue and groove used; whether it is the left tongue and groove or the right tongue and groove; and the thickness of the gasket.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description 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 variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A method for repairing the tenon groove of annular blades of a compressor casing, characterized in that: The repair method comprises the following steps: S1: Determine whether the difference between the actual surface profile of the compressor casing annular tenon groove and the designed maximum profile exceeds the threshold. If it exceeds the threshold, proceed to S2. If it does not exceed the threshold, no repair is required. S2: Process the working surface, fillet and bottom surface of the mortise and tenon groove so that the contour thickness of the three surfaces of the mortise and tenon groove is the same; S3: Select the tongue and groove gasket with the same thickness as the surface profile; S4: Before assembling the blades, first place the tongue-and-groove gasket obtained in S3 into the side of the corresponding tongue-and-groove that exceeds the threshold, and then install the corresponding stator blades.

2. The compressor casing annular blade tenon groove repair method according to claim 1, characterized in that: The tongue and groove gasket is a spare gasket of multiple thicknesses that is processed in advance.

3. The method for repairing the mortise and tenon groove of annular blades of a compressor casing according to claim 2, characterized in that: The thickness difference of the plurality of spare gaskets is 0.02 mm.

4. A compressor casing annular blade tenon groove repair device, characterized in that: The device is used to perform the repair method as described in any one of claims 1 to 3, and includes a left-side mortise gasket and a right-side mortise gasket corresponding to the mortise of the compressor casing annular blade.

5. The compressor casing annular blade tenon groove repair device according to claim 4, characterized in that: The structure and material of the left tongue and groove gasket are the same as those of the right tongue and groove gasket.

6. The compressor casing annular blade tenon groove repair device according to claim 5, characterized in that: The left tongue and groove gasket structure is a V-shaped metal half ring. The V-shaped outer contour coincides with the inner side of the left working area of ​​the mortise, and the V-shaped inner contour is obtained by the outer contour along the normal offset thickness A. The offset thickness A is the same as the out-of-tolerance dimension of the left mortise profile.

7. The compressor casing annular blade tenon groove repair device according to claim 5 or 6, characterized in that: The material of the left tongue and groove gasket is a high-temperature alloy with a hardness greater than 42HRC.

8. The compressor casing annular blade tenon groove repair device according to claim 5 or 6, characterized in that: After the left tongue and groove gasket is processed, the parameters of the left tongue and groove gasket are marked on the surface.

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