Low-pressure turbine stator guide vane assembling method

Abstract

The invention aims to provide a low-pressure turbine stator guide vane assembly method which comprises the following steps: defining a head guide vane and a tail guide vane, inserting a sealing piece into mounting grooves of two adjacent stator guide vanes, and not mounting the sealing piece between the head guide vane and the tail guide vane. All the stator guide vanes are placed in an assembling groove of a turbine case one by one, every two adjacent stator guide vanes are sequentially connected through a flexible connecting piece, no flexible connecting piece is arranged between the head guide vane and the tail guide vane, and the guide vane chain is lifted by a certain height, so that a staggered gap is formed between the head guide vane and the tail guide vane; and the sealing piece is mounted in the mounting groove of the tail guide vane, so that all the stator guide vanes are connected end to end to form a whole ring, and the stator guide vanes with the whole ring formed are placed in the assembling groove of the turbine case. Through the assembling method, the assembling efficiency and the assembling quality of the stator guide vane can be improved.

Description

Technical Field

[0001] The invention relates to the field of gas turbine engine assembly, and in particular to a method for assembling a low-pressure turbine stator guide vane. Background Art

[0002] The low-pressure turbine stator blade assembly process is an important part of aircraft engine assembly. Figures 1 to 3 A schematic diagram of an existing low-pressure turbine rotor and stator unit is shown. The low-pressure turbine rotor and stator unit is composed of a multi-stage rotor 94 and a stator alternatingly. The components of the stator include a turbine casing 90, a stator outer ring 91, stator guide vanes 92 (multiple fan-shaped segments) and a sealing piece 93.

[0003] The connection relationship between the turbine casing 90, the stator outer ring 91, the stator guide vanes 92 and the sealing piece 93 is as follows: Figure 2 as well as Figure 3 As shown, the stator guide vane 92 is fixed on the turbine casing 90 with a cantilever structure, and an annular groove 920 is provided at the front end of the stator guide vane 92, which is clamped in the annular mounting groove of the preceding stator outer ring and the casing, and the rear end is located below the axial limit step 901 of the turbine casing 90 and is clamped in the annular groove of the turbine casing through the front annular groove 910 of the stator outer ring 91. The stator guide vane 92 is a fan-shaped segment structure. To prevent gas leakage, a plurality of sealing pieces 93 are provided between the inner edge plate and the outer edge plate of adjacent guide vanes to block the joints between the guide vanes.

[0004] However, the applicant has found that in the existing low-pressure turbine stator blade assembly process, there are still difficulties in assembling the sealing piece. Summary of the invention

[0005] The object of the present invention is to provide a method for assembling a low-pressure turbine stator guide vane, which can improve the assembly efficiency and assembly quality of the stator guide vane.

[0006] A method for assembling a low-pressure turbine stator guide vane to achieve the above-mentioned purpose comprises the following steps:

[0007] a. A pair of adjacent stator guide vanes are defined along the annular direction as the first guide vane and the tail guide vane;

[0008] b. inserting the sealing piece into the mounting grooves of two adjacent stator guide vanes, wherein the sealing piece is not installed between the first guide vane and the tail guide vane;

[0009] c. Place all stator guide vanes one by one into the assembly slots of the turbine casing;

[0010] d. The two adjacent stator guide vanes are sequentially connected by a flexible connector to form a guide vane chain, and the flexible connector is not provided between the first guide vane and the tail guide vane;

[0011] e. applying a lifting force at the first guide vane and the tail guide vane respectively to lift the guide vane chain to a certain height;

[0012] f. When the guide vane chain is lifted, a dislocation gap is formed between the first guide vane and the tail guide vane until the width of the dislocation gap is greater than the width of the sealing piece to be assembled;

[0013] g. After installing the sealing piece into the mounting groove of the tail guide vane, lift the first guide vane or the tail guide vane so that all the stator guide vanes are connected head to tail to form a complete ring;

[0014] h. Place the stator guide vanes after forming a complete ring into the assembly groove of the turbine casing, remove the flexible connector, and then insert the plurality of stator guide vanes into the axial limit steps of the turbine casing respectively.

[0015] In one or more embodiments, in step b, it also includes inserting the sealing sheet into the installation grooves of two adjacent stator guide vanes after applying adhesive in the installation grooves of the stator guide vanes.

[0016] In one or more embodiments, the binder is petrolatum.

[0017] In one or more embodiments, the flexible connector is a cable tie or a binding rope.

[0018] In one or more embodiments, in step e, during the lifting process, lifting forces in different directions are applied to the head guide vane and the tail guide vane, so that during the lifting process of the guide vane chain, the head guide vane and the tail guide vane gradually break contact with each other to form the misaligned gap in step f.

[0019] In one or more embodiments, in step h, the external force applied to the stator guide vanes is gradually and synchronously increased in a clockwise or counterclockwise direction until all the stator guide vanes are straightened and snapped under the axial limit step of the casing.

[0020] In one or more embodiments, step h also includes using a clamp to clamp the plurality of stator guide vanes respectively under the axial limit step of the turbine casing.

[0021] In one or more embodiments, the clamp includes an inner clamp and an outer clamp, and the outer clamp and the inner clamp can move relative to or toward each other to clamp the plurality of stator guide vanes respectively under the axial limit step of the turbine casing.

[0022] In one or more embodiments, the clamp further includes a screw and a guide rod, the outer clamp has a through hole, the end of the screw passes through the through hole and is connected to a limit ring, the limit ring limits the screw from coming out of the through hole, and the screw is rotatably connected to the through hole; the inner clamp is threadedly connected to the screw, the guide rod extends from the outer clamp toward the inner clamp, a guide hole is provided in the inner clamp at a position corresponding to the guide rod, and the guide rod extends into the guide hole;

[0023] When the screw rod is rotated, the inner clamping plate can be driven to move toward or away from the outer clamping plate, and the guide rod cooperates with the guide hole to guide the movement direction of the inner clamping plate.

[0024] In one or more embodiments, step h further comprises:

[0025] Installing the clamp on each stator guide vane in sequence;

[0026] Rotate the screw rod so that the outer clamping plate and the inner clamping plate are in contact with the stator guide vane and the casing respectively;

[0027] Select any guide vane, and tighten the screw so that the inner clamping plate and the outer clamping plate jointly apply a clamping force to the guide vane;

[0028] Tighten the clamps on each stator guide vane in turn in a clockwise or counterclockwise direction, so that all clamps apply clamping force to the corresponding guide vane;

[0029] The clamping force is gradually and synchronously increased in a clockwise or counterclockwise direction until all stator guide vanes are straightened and snapped under the axial limit step of the casing.

[0030] In one or more embodiments, a force sensor is provided on the outer clamping plate and / or the inner clamping plate, and the magnitude of the clamping force is determined by the force sensor.

[0031] In one or more embodiments, after all the stator guide vanes are stuck under the axial limit step of the casing, select any stator guide vane, remove the clamp installed on the stator guide vane, install the stator outer ring to fix the stator guide vane, remove the clamp in turn in a clockwise or counterclockwise direction, and install the stator outer ring to fix the stator guide vane in turn.

[0032] In one or more embodiments, the clamp is mounted on a mid-section of the stator guide vane.

[0033] In one or more embodiments, in the assembled state, the operating end of the screw is arranged toward the inside of the low-pressure turbine.

[0034] The beneficial effects of the present invention are:

[0035] Through this assembly method, flexible connectors are used to connect adjacent guide vanes in pairs to form a flexible chain shape, which makes it easy to form a circumferential offset gap to meet the installation of the sealing piece. After the sealing piece is installed, the first and last guide vanes are overlapped at a high position and then put back into the turbine casing, which can solve the problem of installing the sealing piece on the last guide vane and achieve efficient damage-free installation of the guide vane.

[0036] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0038] Figures 1 to 3 A schematic diagram of an existing low-pressure turbine rotor and stator unit is shown;

[0039] Figure 4 A schematic flow chart of a method for assembling a low-pressure turbine stator guide vane according to one or more embodiments of the present application is shown;

[0040] Figure 5 A schematic diagram showing a guide vane chain formed by connecting a low-pressure turbine stator guide vane assembly method according to one or more embodiments of the present application;

[0041] Figure 6 A schematic diagram showing a method for assembling a low-pressure turbine stator guide vane and fixing a sealing piece according to one or more embodiments of the present application is shown;

[0042] Figure 7 A schematic diagram showing a clamp in an assembled state according to one or more embodiments of the present application is shown;

[0043] Figure 8 A three-dimensional schematic diagram of a clamp according to some embodiments of the present application is shown;

[0044] Fig. 9 A schematic cross-sectional view of a clamp in an installed state according to some embodiments of the present application is shown. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0047] When the applicant used the existing assembly process to assemble the low-pressure turbine stator blades, it was found that the current installation of the turbine stator had the following two difficulties:

[0048] 1. Installation of sealing pieces. There are two difficulties in installing sealing pieces: 1) There are many sealing pieces, which are small in size and thin in thickness. They are easy to fall out of the guide vane installation groove. Once they fall, they will enter the engine flow path and cannot be taken out. The fallen sealing pieces can only be taken out by disassembling the entire low-pressure turbine rotor and stator unit; 2) When assembling in sequence along the circumferential direction, the sealing piece on the last guide vane is extremely difficult to install. The width of the sealing piece is much larger than the circumferential gap between adjacent guide vanes. The sealing piece cannot be directly inserted into the installation groove by side installation. It is often necessary to repeatedly adjust the relative position of each guide vane (both circumferential and axial adjustments are required) before the last set of sealing pieces can be inserted into the installation groove. The sealing pieces on each guide vane can easily fall off during the adjustment and movement of the guide vanes.

[0049] 2. The rear end of the stator guide vane is attached to the inner wall of the turbine casing and inserted under the axial limit step. A single guide vane is cantilevered and fixed. The blade is heavy and naturally tilts inward after being placed. After the stator guide vane forms a whole ring, it becomes an integral structure and affects each other under the connection of the sealing piece. It is extremely difficult to straighten each blade one by one and insert it under the axial limit step of the casing by knocking. If violent knocking is used to install a certain blade in place, the sealing piece on the guide vane will be severely deformed by shear force (once the sealing piece is deformed, it will make it difficult to disassemble the guide vane later), making it impossible to assemble the remaining guide vanes in place. Violent knocking will also cause damage to the guide vane.

[0050] In order to solve the above problems existing in the existing stator guide vane assembly method, on the one hand, according to some embodiments of the present application, a low-pressure turbine stator guide vane assembly method is provided, such as Figure 4 A schematic flow chart of a method for assembling a low-pressure turbine stator guide vane according to one or more embodiments of the present application is shown. The method for assembling a low-pressure turbine stator guide vane comprises the following steps:

[0051] Step a: Define a pair of adjacent stator guide vanes along the circumferential direction as the head guide vane and the tail guide vane, for example Figure 5 As shown, any pair of adjacent stator guide vanes is selected from a plurality of stator guide vanes as the head guide vane 1 and the tail guide vane 2. The annular direction mentioned in the text can be understood as the arrangement direction of the plurality of stator guide vanes after being assembled into a complete ring.

[0052] Step b: inserting the sealing piece into the installation groove of two adjacent stator guide vanes, wherein no sealing piece is installed between the first guide vane 1 and the tail guide vane 2.

[0053] Step c: placing all stator guide vanes one by one into the assembly grooves of the turbine casing, so that the plurality of stator guide vanes are arranged roughly in a ring shape.

[0054] Step d: Use the flexible connector 3 to connect two adjacent stator guide vanes in sequence to form a guide vane chain. No flexible connector 3 is provided between the first guide vane 1 and the tail guide vane 2. The guide vane chain formed by the connection is as follows: Figure 5 As shown, neither a sealing piece nor a flexible connecting member 3 is installed between the front guide vane 1 and the rear guide vane 2 .

[0055] Step e: applying lifting force to the leading guide vane 1 and the trailing guide vane 2 respectively to lift the guide vane chain to a certain height. For example, in a specific embodiment, a lifting operation is performed at the leading guide vane 1 and the trailing guide vane 2 using a lifting device to lift the guide vane chain to a certain height.

[0056] Step f: When the guide vane chain is lifted, a dislocation gap 4 is formed between the head guide vane 1 and the tail guide vane 2 until the width of the dislocation gap 4 is larger than the width of the sealing piece to be assembled. At this time, the sealing piece to be assembled can be placed into the dislocation gap 4 formed between the head and the tail for assembly.

[0057] Step g: After installing the sealing piece into the installation groove 20 of the tail guide vane 2, lift the head guide vane 1 or the tail guide vane 2 so that all the stator guide vanes are connected head to tail to form a complete ring. Figure 5 In the embodiment shown in the figure, the front guide vane 1 is lower than the rear guide vane 2. At this time, after the sealing piece is installed in the installation groove 20, the front guide vane 1 can be lifted to achieve the end-to-end connection of all the stator guide vanes and form a complete ring. In some other embodiments different from those shown in the figure, the relative position of the front guide vane 1 is higher than the rear guide vane 2 to form a misaligned gap 4. At this time, after the sealing piece is installed in the installation groove 20, the rear guide vane 2 can be lifted to achieve the end-to-end connection of all the stator guide vanes and form a complete ring.

[0058] Step h: Place the stator guide vanes formed into a complete ring into the assembly groove of the turbine casing, remove the flexible connector 3, and then insert the multiple stator guide vanes into the axial limit steps of the turbine casing respectively, thereby completing the overall assembly of the low-pressure turbine stator guide vanes.

[0059] Through this assembly method, flexible connectors are used to connect adjacent guide vanes in pairs to form a flexible chain shape, which makes it easy to form a circumferential offset gap to meet the installation of the sealing piece. After the sealing piece is installed, the first and last guide vanes are overlapped at a high position and then put back into the turbine casing, which can solve the problem of installing the sealing piece on the last guide vane and achieve efficient damage-free installation of the guide vane.

[0060] In the description of the embodiments of the present application, “plurality” means more than two, unless otherwise clearly and specifically defined.

[0061] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0062] In one or more embodiments, in step b, it further includes coating the adhesive in the installation groove of the stator guide vane and inserting the sealing sheet into the installation groove of two adjacent stator guide vanes. Figure 6 As shown, the mounting groove 20 of the stator guide vane is coated with an adhesive. At this time, the sealing piece 5 is installed in the mounting groove 20, so that the sealing piece 5 can be firmly fixed in the mounting groove 20 to prevent the sealing piece 5 from falling off from the mounting groove 20 during the installation process.

[0063] In a specific embodiment, the adhesive is vaseline, and the sealing sheet is bonded to the installation groove by relying on the viscosity of the vaseline to prevent the sealing sheet from falling off.

[0064] In a specific embodiment, the flexible connector 3 is a cable tie or a binding rope. When releasing the connection between multiple stator guide vanes, the flexible connector 3 can be cut by scissors, thereby improving assembly efficiency.

[0065] In one or more embodiments, in step e, during the lifting process, lifting forces in different directions are applied to the head guide vane 1 and the tail guide vane 2, so that during the lifting process of the guide vane chain, the head guide vane 1 and the tail guide vane 2 gradually break contact, so as to form the dislocation gap 4 in step f. In a specific embodiment, the lifting forces in different directions can be lifting forces in different directions and at a certain angle to the height direction, preferably, the angle to the height direction is within 45°, and more preferably, the angle is within 20°.

[0066] In one or more embodiments, in step h, Figure 7As shown, the external force applied to the stator guide vanes is gradually and synchronously increased in a clockwise or counterclockwise direction until all the stator guide vanes are straightened and snapped under the axial limit step of the casing.

[0067] In a specific embodiment, a plurality of stator guide vanes are clamped under the axial limit steps of the turbine casing by the clamp 6 .

[0068] In a specific embodiment, Figure 8 shows a three-dimensional schematic diagram of a clamp according to some embodiments of the present application, Fig. 9 The cross-sectional schematic diagram of the clamp in the installed state according to some embodiments of the present application is shown. The clamp 6 includes an inner clamping plate 61 and an outer clamping plate 62, and the inner clamping plate 61 and the outer clamping plate 62 can move relative to or towards each other to achieve clamping of the stator guide vanes.

[0069] In a specific embodiment, the clamp 6 further includes a screw 63 and a guide rod 64. The outer clamp 62 has a through hole 620. The end of the screw 63 passes through the through hole 620 and is connected to a stop ring 65. The stop ring 65 limits the screw 63 from slipping out of the through hole 620. In a specific embodiment, a shoulder 630 is also provided on the screw 63. The shoulder 630 and the stop ring 65 jointly limit the movement of the screw 63 in the through hole 620 along the extending direction of the through hole 620. The screw 63 is rotatably connected in the through hole 620. The inner clamp 61 is threadedly connected to the screw 63. The guide rod 64 extends from the outer clamp 62 toward the inner clamp 61. A guide hole is provided in the inner clamp 61 at a position corresponding to the guide rod 64. The guide rod 64 in the assembled state extends into the guide hole. When the screw rod 63 is rotated, the inner clamping plate 61 can be driven to move toward or away from the outer clamping plate 62 , and the guide rod 64 cooperates with the guide hole to guide the movement direction of the inner clamping plate 61 .

[0070] In a specific embodiment, please refer to Figures 7 to 9 , step h also includes:

[0071] Install the clamp 6 on each stator guide vane in sequence;

[0072] Rotate the screw 63 so that the outer clamping plate 62 and the inner clamping plate 61 are in contact with the stator guide vane 92 and the casing 90 respectively;

[0073] Select any guide vane, and tighten the screw so that the inner clamping plate 61 and the outer clamping plate 62 jointly apply a clamping force to the guide vane;

[0074] Tighten the clamps 6 on each stator guide vane in turn in a clockwise or counterclockwise direction, so that all the clamps 6 apply a clamping force to the corresponding guide vane; in a specific embodiment, when tightened for the first time, the clamping force applied by the clamp 6 is F.

[0075] The clamping force is gradually and synchronously increased in a clockwise or counterclockwise direction until all stator guide vanes are straightened and snapped under the axial limit step of the casing. In a specific embodiment, the clamping force applied by multiple clamps 6 is sequentially increased to F+f in a clockwise or counterclockwise direction, and then the above operation is repeated, and the clamping force applied by multiple clamps 6 is sequentially increased to F+2f, and the above operation is repeated until all guide vanes are straightened and snapped under the axial limit step of the casing.

[0076] Such arrangement enables the clamping force to be gradually increased when assembling the stator guide vanes, so that each guide vane can be slowly pressed under the axial limit step of the casing after multiple cycles. In each round of operation, the feed amount of the guide vane is small, and the sealing piece will not be sheared and deformed.

[0077] In a specific embodiment, the operating end of the screw rod 63 is directed toward the inside of the turbine disk as shown in the figure, so that the operating space is open and easy to operate.

[0078] In a specific embodiment, a force sensor 66 is provided on the outer splint 62 and / or the inner splint 61, and the magnitude of the clamping force is determined by the force sensor 66. In the description of the embodiment of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, the outer splint and / or the inner splint may represent the following three situations: existing alone on the outer splint, existing on both the outer splint and the inner splint, and existing alone on the inner splint. In addition, the character " / " in this article generally indicates that the front and rear associated objects are in an "or" relationship. By providing a force sensor 66, the clamping force exerted on each guide vane can be fed back, and the radial stepping amount of the guide vane can be controlled by the clamping force to avoid shear deformation of the sealing piece, which makes it difficult to disassemble the guide vane.

[0079] In a specific embodiment, after all the stator guide vanes are stuck under the axial limit step of the casing, select any stator guide vane, remove the clamp 6 installed on the stator guide vane, install the stator outer ring to fix the stator guide vane, remove the clamp 6 in turn in a clockwise or counterclockwise direction, and install the stator outer ring to fix the stator guide vane in turn.

[0080] In a specific embodiment, when clamping the stator guide vane, the clamp 6 is installed on the middle section of the stator guide vane to achieve stable clamping of the stator guide vane.

[0081] Through the above-mentioned installation method, it is possible to effectively solve the problems of sealing pieces falling off, the sealing piece on the last guide vane being extremely difficult to install, and the guide vanes affecting each other and tilting inward, resulting in the inability to be inserted under the axial limit step of the casing, thereby efficiently achieving damage-free installation of the guide vanes.

[0082] In the description of the embodiments of the present application, the orientation or position relationship indicated by the technical terms "clockwise", "counterclockwise", "circumferential", etc. is based on the orientation or position relationship of the connecting component in the connected state, and is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0083] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for assembling a low-pressure turbine stator guide vane, characterized in that: The steps include: a. A pair of adjacent stator guide vanes are defined along the annular direction as the first guide vane and the tail guide vane; b. inserting the sealing piece into the mounting grooves of two adjacent stator guide vanes, wherein the sealing piece is not installed between the first guide vane and the tail guide vane; c. Place all stator guide vanes one by one into the assembly slots of the turbine casing; d. The two adjacent stator guide vanes are sequentially connected by a flexible connector to form a guide vane chain, and the flexible connector is not provided between the first guide vane and the tail guide vane; e. applying a lifting force at the first guide vane and the tail guide vane respectively to lift the guide vane chain to a certain height; f. When the guide vane chain is lifted, a dislocation gap is formed between the first guide vane and the tail guide vane until the width of the dislocation gap is greater than the width of the sealing piece to be assembled; g. After installing the sealing piece into the mounting groove of the tail guide vane, lift the first guide vane or the tail guide vane so that all the stator guide vanes are connected head to tail to form a complete ring; h. Place the stator guide vanes after forming a complete ring into the assembly groove of the turbine casing, remove the flexible connector, and then insert the plurality of stator guide vanes into the axial limit steps of the turbine casing respectively.

2. The low-pressure turbine stator guide vane assembly method according to claim 1, characterized in that: In step b, it also includes coating the adhesive in the installation groove of the stator guide vane, and then inserting the sealing sheet into the installation grooves of two adjacent stator guide vanes.

3. The low-pressure turbine stator guide vane assembly method according to claim 2, characterized in that: The binder is vaseline.

4. The low-pressure turbine stator guide vane assembly method according to claim 1, characterized in that: The flexible connecting piece is a cable tie or a binding rope.

5. The low-pressure turbine stator guide vane assembly method according to claim 1, characterized in that: In step e, during the lifting process, lifting forces in different directions are applied to the head guide vane and the tail guide vane, so that during the lifting process of the guide vane chain, the head guide vane and the tail guide vane gradually break contact with each other to form the offset gap in step f.

6. The low-pressure turbine stator guide vane assembly method according to claim 1, characterized in that: In step h, the external force applied to the stator guide vanes is gradually and synchronously increased in a clockwise or counterclockwise direction until all the stator guide vanes are straightened and snapped under the axial limit step of the casing.

7. The low-pressure turbine stator guide vane assembly method according to claim 1, characterized in that: Step h also includes using a clamp to clamp the plurality of stator guide vanes respectively under the axial limit step of the turbine casing.

8. The low-pressure turbine stator guide vane assembly method according to claim 7, characterized in that: The clamp comprises an inner clamping plate and an outer clamping plate, and the outer clamping plate and the inner clamping plate can move relative to or towards each other to clamp the plurality of stator guide vanes respectively under the axial limiting steps of the turbine casing.

9. The low-pressure turbine stator guide vane assembly method according to claim 8, characterized in that: The clamp further comprises a screw and a guide rod, the outer clamping plate having a through hole, the end of the screw passing through the through hole is connected to a limit ring, the limit ring restricts the screw from coming out of the through hole, and the screw is rotatably connected to the through hole; the inner clamping plate is threadedly connected to the screw, the guide rod extends from the outer clamping plate toward the inner clamping plate, a guide hole is provided in the inner clamping plate at a position corresponding to the guide rod, and the guide rod extends into the guide hole; When the screw rod is rotated, the inner clamping plate can be driven to move toward or away from the outer clamping plate, and the guide rod cooperates with the guide hole to guide the movement direction of the inner clamping plate.

10. The low-pressure turbine stator guide vane assembly method according to claim 9, characterized in that: Step h also includes: Installing the clamp on each stator guide vane in sequence; Rotate the screw rod so that the outer clamping plate and the inner clamping plate are in contact with the stator guide vane and the casing respectively; Select any guide vane, and tighten the screw so that the inner clamping plate and the outer clamping plate jointly apply a clamping force to the guide vane; Tighten the clamps on each stator guide vane in turn in a clockwise or counterclockwise direction, so that all clamps apply clamping force to the corresponding guide vane; The clamping force is gradually and synchronously increased in a clockwise or counterclockwise direction until all stator guide vanes are straightened and snapped under the axial limit step of the casing.

11. The low-pressure turbine stator guide vane assembly method according to claim 10, characterized in that: The outer clamping plate and / or the inner clamping plate are provided with a force sensor, and the magnitude of the clamping force is determined by the force sensor.

12. The low-pressure turbine stator guide vane assembly method according to claim 10, characterized in that: When all the stator guide vanes are stuck under the axial limit step of the casing, select any stator guide vane, remove the clamp installed on the stator guide vane, install the stator outer ring to fix the stator guide vane, and remove the clamp in turn in a clockwise or counterclockwise direction, and install the stator outer ring to fix the stator guide vane in turn.

13. The low-pressure turbine stator guide vane assembly method according to claim 11, characterized in that: The clamp is installed on the middle section of the stator guide vane.

14. The low-pressure turbine stator guide vane assembly method according to claim 11, characterized in that: In the assembled state, the operating end of the screw is arranged toward the inside of the low-pressure turbine.

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