Method of discing a steam turbine rotor

Abstract

The present application relates to the technical field of steam turbine, and especially relates to a method for rotating the rotor of steam turbine, wherein after the upper half bearing bush of the steam turbine is removed, the high-pressure rotor and the low-pressure rotor of the steam turbine are limited from moving along the axial direction by using a limiting tool, then the shaft coupling between the high-pressure rotor and the low-pressure rotor is removed, a plurality of disc pin shafts are inserted on the low-pressure rotor, a sling is arranged around the disc pin shaft, the other end of the sling is connected with a travelling crane, the low-pressure rotor is rotated by starting the travelling crane to move the sling, and in this process, lubricating oil is continuously added into the lower half bearing bush located at the low-pressure rotor; then the disc pin shaft is removed and inserted on the high-pressure rotor, the high-pressure rotor is rotated by the travelling crane through the sling, and in this process, lubricating oil is continuously added into the lower half bearing bush located at the high-pressure rotor. The present application can ensure the smooth rotation of the rotor of steam turbine, ensure the accuracy of the measurement result of the center finding of the rotor, and reduce the damage to the bearing bush.

Description

Technical Field

[0001] This invention relates to the field of steam turbine technology, and more particularly to a method for rotating a steam turbine rotor. Background Technology

[0002] During a steam turbine overhaul, the coupling will be disassembled and reassembled. After the coupling is disassembled, the high-pressure rotor and low-pressure rotor need to be aligned. This alignment requires rotating the turbine rotor. To complete the alignment, external force is needed to rotate the turbine rotor.

[0003] From a technical perspective, firstly, the turbine rotors are currently quite heavy, and the weight increases even more after several low-pressure rotors are connected to the high-pressure rotor. Therefore, the friction between the turbine rotor and the bearing is significant, requiring considerable force to rotate the rotor. Secondly, due to the rotor's own weight and considerable length, after a period of rest, a sag effect will occur in the middle section of the rotor, resulting in significant sag and overall rotor deformation, thus requiring a greater external force to push the rotor. Thirdly, because the rotor has a certain lift after installation, axial movement will occur during rotor rotation, causing deviations in the rotor's centering measurement results. Furthermore, due to the rotor's own weight, the lubricating oil between the rotor and the bearing will decrease over time due to the rotor's compression; if forced rotation is performed, it will damage the bearing's burr surface.

[0004] Therefore, a method for rotating the turbine rotor is needed to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for rotating a steam turbine rotor, which can ensure the smooth rotation of the steam turbine rotor, ensure the accuracy of the rotor centering measurement results, and reduce damage to the bearings.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The method of rotating the turbine rotor includes the following steps:

[0008] S1. Remove the upper half of the turbine's bearing shell;

[0009] S2. Install a limiting fixture on the steam turbine, the limiting fixture being used to restrict the axial movement of the high-pressure rotor and the low-pressure rotor of the steam turbine;

[0010] S3. Remove the coupling between the high-pressure rotor and the low-pressure rotor, and insert multiple disc pins onto the low-pressure rotor.

[0011] S4. A sling is wound around multiple disc pins along the circumference of the low-pressure rotor, and the other end of the sling is connected to the crane.

[0012] S5. Start the crane to move a first set distance, thereby driving the low-pressure rotor to rotate through the sling. During this process, lubricating oil is continuously added to the lower half bearing located at the low-pressure rotor.

[0013] S6. Remove the disc pin and insert it onto the high-pressure rotor;

[0014] S7. The sling is wound around the multiple disc pins along the circumference of the high-pressure rotor, and the other end of the sling is connected to the crane.

[0015] S8. Start the crane to move a second set distance, thereby driving the high-pressure rotor to rotate through the sling. During this process, lubricating oil is continuously added to the lower half bearing located at the high-pressure rotor.

[0016] Furthermore, in step S2, an anti-overturning bearing tool is installed on the turbine, with one end of the anti-overturning bearing tool pressing against the end face of the lower half bearing to prevent the lower half bearing from rotating with the high-pressure rotor or the low-pressure rotor of the turbine.

[0017] Furthermore, in step S2, if multiple low-pressure rotors are connected in series, multiple disc pins are inserted on at least two of the low-pressure rotors, and multiple trolleys correspond one-to-one with multiple low-pressure rotors, and are all connected by the slings.

[0018] Furthermore, in step S5, the vehicle starts in the lowest gear and increases the output torque according to a set step size until it moves a first set distance.

[0019] Furthermore, after the high-pressure rotor and the low-pressure rotor have stopped rotating for a first period of time, it is necessary to rotate the high-pressure rotor and the low-pressure rotor again.

[0020] Furthermore, if the high-pressure rotor and the low-pressure rotor stop rotating for more than the first time period, the high-pressure rotor and all the low-pressure rotors are completely detached and lifted up. Lubricating oil is added to all the lower half bearings for no less than the second time period. Then, the high-pressure rotor and all the low-pressure rotors are reset and rotated individually for a set number of revolutions.

[0021] Furthermore, after completing the set number of individual rotations, the low-pressure rotors are connected in series using a coupling for overall rotation.

[0022] Furthermore, during the process of rotating the high-pressure rotor and the low-pressure rotor, lubricating oil needs to be continuously added to the corresponding lower half bearing.

[0023] Furthermore, the multiple disc pins are evenly distributed on both the low-pressure rotor and the high-pressure rotor.

[0024] Furthermore, in step S8, the vehicle starts in the lowest gear and increases the output torque by a set step size until it moves a second set distance.

[0025] The beneficial effects of this invention are:

[0026] This invention provides a method for rotating a steam turbine rotor. After removing the upper bearing shell of the steam turbine, a limiting fixture is used to restrict the axial movement of the high-pressure and low-pressure rotors. Then, the coupling between the high-pressure and low-pressure rotors is removed, and multiple rotating pins are inserted into the low-pressure rotor. A sling is wound around each rotating pin, with the other end of the sling connected to a trolley. The trolley is started to move the rotor, thereby rotating the low-pressure rotor via the sling. During this process, lubricating oil is continuously added to the lower bearing shell located on the low-pressure rotor. The rotating pins are then removed and inserted into the high-pressure rotor. The trolley, via the sling, rotates the high-pressure rotor, and lubricating oil is continuously added to the lower bearing shell located on the high-pressure rotor during this process. This method ensures sufficient lubrication between the rotor and the lower bearing shell, thus preventing damage to the metal surface of the lower bearing shell during rotation. By using a crane to drive the slings wound around the disc pin shaft, the high-pressure rotor and the low-pressure rotor are rotated. Moreover, the high-pressure rotor and the low-pressure rotor rotate separately, which reduces the torque required for rotation and thus ensures that the turbine rotor rotates smoothly. By setting limit fixtures, the axial movement of the high-pressure rotor and the low-pressure rotor of the turbine is restricted, thereby reducing the deviation of the rotor centering measurement results and ensuring the accuracy of the rotor centering measurement results. Attached Figure Description

[0027] Figure 1 This is a flowchart of a method for rotating a steam turbine rotor according to the present invention;

[0028] Figure 2 This is a schematic diagram of the steam turbine in a method for rotating a steam turbine rotor according to the present invention;

[0029] Figure 3 This is a schematic diagram of the installation of the limiting tooling in a method for rotating a steam turbine rotor according to the present invention;

[0030] Figure 4 This is a schematic diagram of the installation of the anti-tumbler tool in a method for rotating a steam turbine rotor according to the present invention.

[0031] In the picture:

[0032] 1. High-pressure rotor; 2. Low-pressure rotor; 3. Lower half bearing; 4. Limiting fixture; 5. Anti-tipping bearing tool. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0034] In the description of this invention, 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 fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] During turbine overhaul, in order to ensure smooth rotor rotation, accurate rotor alignment measurements, and minimize damage to the bearings, such as... Figures 1-4 As shown, the present invention provides a method for rotating a steam turbine rotor. The method for rotating a steam turbine rotor includes the following steps:

[0037] S1. Remove the upper half of the turbine's bearing shell;

[0038] S2. Install a limiting fixture 4 on the steam turbine. The limiting fixture 4 is used to restrict the high-pressure rotor 1 and the low-pressure rotor 2 of the steam turbine from moving axially.

[0039] S3. Remove the coupling between the high-pressure rotor 1 and the low-pressure rotor 2, and insert multiple disc pins into the low-pressure rotor 2.

[0040] S4. A sling is wound around multiple disc pins along the circumference of the low-pressure rotor 2, and the other end of the sling is connected to the crane.

[0041] S5. Start the crane and move it a first set distance, thereby driving the low-pressure rotor 2 to rotate through the sling. During this process, lubricating oil is continuously added to the lower half bearing 3 located at the low-pressure rotor 2.

[0042] S6. Remove the disc pin and insert it onto the high-pressure rotor 1;

[0043] S7. A sling is wound around multiple disc pins along the circumference of the high-pressure rotor 1, and the other end of the sling is connected to the crane.

[0044] S8. Start the crane to move the second set distance, thereby driving the high-pressure rotor 1 to rotate through the sling. During this process, lubricating oil is continuously added to the lower half bearing 3 located at the high-pressure rotor 1.

[0045] The above methods ensure sufficient lubrication between the rotor and the lower bearing shell 3, preventing damage to the black surface of the lower bearing shell 3 during rotation. The high-pressure rotor 1 and the low-pressure rotor 2 are rotated separately by a crane driving a sling wound around the disc pin shaft, reducing the torque required for rotation and ensuring smooth rotor rotation. The limiting fixture 4 restricts axial movement of the high-pressure rotor 1 and the low-pressure rotor 2, reducing deviations in rotor centering measurements and ensuring accuracy.

[0046] Further, in step S2, an anti-tipping bearing tool 5 is installed on the turbine. One end of the anti-tipping bearing tool 5 presses against the end face of the lower half-bearing bearing 3 to prevent the lower half-bearing bearing 3 from rotating with the high-pressure rotor 1 or the low-pressure rotor 2 of the turbine. Since the upper half-bearing bearing is removed, the rotation of the high-pressure rotor 1 or the low-pressure rotor 2 may cause the lower half-bearing bearing 3 to rotate, thus changing its position and affecting the measurement results. By setting the anti-tipping bearing tool 5, the rotation of the lower half-bearing bearing 3 is limited, thereby preventing changes in its position.

[0047] Furthermore, in step S2, if multiple low-pressure rotors 2 are connected in series, multiple disc pins are inserted into at least two low-pressure rotors 2. Multiple gantry cranes correspond one-to-one with multiple low-pressure rotors 2 and are all connected by slings. In this embodiment, three-stage low-pressure rotors 2 are connected in series, and two gantry cranes are arranged for disc rotation. Since the connected low-pressure rotors 2 are relatively long and heavy, rotating multiple low-pressure rotors 2 simultaneously can evenly distribute the force on the shaft system. Moreover, because the torque for rotating the low-pressure rotors 2 is large, 100t slings are used to prevent sling breakage, ensuring personal safety.

[0048] Furthermore, in step S5, the trolley starts in the lowest gear and increases the output torque according to the set step size until it moves the first set distance. This ensures the smooth rotation of the low-pressure rotor 2, and by continuously adding lubricating oil during this process, it ensures the smooth rotation of the low-pressure rotor 2 relative to the lower half-shaft bearing 3.

[0049] Due to the weight of the high-pressure rotor 1 and the low-pressure rotor 2, if they remain stationary, residual oil between them and the lower bearing 3 will be discharged due to their own weight. This results in excessive friction between the high-pressure rotor 1 and the low-pressure rotor 2 and the bearing, leading to excessive turning torque, even exceeding the applicable range for the vehicle. To address this issue, after the high-pressure rotor 1 and the low-pressure rotor 2 have stopped rotating for a first period of time, they need to be turned again. In this embodiment, the first set time is 24 hours. In other embodiments, the first time can be set according to actual needs, without further restrictions. By turning again after the first period, lubricating oil can be replenished in time, ensuring that the high-pressure rotor 1 and the low-pressure rotor 2 can be turned smoothly.

[0050] Furthermore, if the high-pressure rotor 1 and the low-pressure rotor 2 stop rotating for more than a first time period, then the high-pressure rotor 1 and all the low-pressure rotors 2 are completely detached and lifted. Lubricating oil is added to all the lower half-shaft bearings 3 for at least a second time period. Then, the high-pressure rotor 1 and all the low-pressure rotors 2 are reset and individually rotated a set number of revolutions. In this embodiment, the second time period is 8 hours. In other embodiments, the second time period can be set according to actual needs, and no further restrictions are imposed here. By fully lubricating the lower half-shaft bearings 3 before rotating them, the rotation operation can be carried out smoothly. Moreover, by rotating the high-pressure rotor 1 and the low-pressure rotor 2 individually, the required torque can be reduced.

[0051] Furthermore, after completing the set number of individual rotations, the low-pressure rotor 2 is connected in series using a coupling for overall rotation. Once individual rotations are successful, connecting them in series allows for rotation testing of the entire low-pressure rotor 2 as needed.

[0052] Furthermore, during the rotation of the high-pressure rotor 1 and the low-pressure rotor 2, lubricating oil needs to be continuously added to the corresponding lower bearing shell 3. This ensures the smooth rotation of the high-pressure rotor 1 and the low-pressure rotor 2 relative to the lower bearing shell 3.

[0053] Furthermore, the multiple disc pins are evenly distributed on both the low-pressure rotor 2 and the high-pressure rotor 1. This even distribution ensures the smooth rotation of either the high-pressure rotor 1 or the low-pressure rotor 2.

[0054] Furthermore, in step S8, the trolley starts in the lowest gear and increases the output torque according to the set step size until it moves the second set distance. This ensures that the high-pressure rotor 1 rotates smoothly, and by continuously adding lubricating oil during this process, it ensures that the low-pressure rotor 2 rotates smoothly relative to the lower half-shaft bearing 3.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for rotating a steam turbine rotor, characterized in that, Includes the following steps: S1. Remove the upper half of the turbine's bearing shell; S2. Install a limiting fixture (4) on the steam turbine. The limiting fixture (4) is used to restrict the high-pressure rotor (1) and low-pressure rotor (2) of the steam turbine from moving axially. S3. Remove the coupling between the high-pressure rotor (1) and the low-pressure rotor (2), and insert multiple disc pins into the low-pressure rotor (2). S4. A sling is wound around a plurality of disc pins along the circumference of the low-pressure rotor (2), and the other end of the sling is connected to the crane. S5. Start the crane to move a first set distance, thereby driving the low-pressure rotor (2) to rotate through the sling. During this process, continuously add lubricating oil to the lower half bearing (3) located at the low-pressure rotor (2). S6. Remove the disc pin and insert it into the high-pressure rotor (1); S7. The sling is wound around the multiple disc pins along the circumference of the high-pressure rotor (1), and the other end of the sling is connected to the crane. S8. Start the crane to move a second set distance, thereby driving the high-pressure rotor (1) to rotate through the sling. During this process, continuously add lubricating oil to the lower half bearing (3) located at the high-pressure rotor (1). In step S2, if multiple low-pressure rotors (2) are connected in series, multiple disc pins are inserted on at least two of the low-pressure rotors (2), and multiple trolleys correspond one-to-one with multiple low-pressure rotors (2), and are all connected by the slings.

2. The method for rotating a steam turbine rotor according to claim 1, characterized in that, In step S2, an anti-overturning bearing tool (5) is installed on the turbine. One end of the anti-overturning bearing tool (5) is pressed against the end face of the lower half bearing (3) to prevent the lower half bearing (3) from rotating with the high-pressure rotor (1) or the low-pressure rotor (2) of the turbine.

3. The method for rotating a steam turbine rotor according to claim 1, characterized in that, In step S5, the vehicle starts in the lowest gear and increases the output torque according to a set step size until it moves a first set distance.

4. The method for rotating a steam turbine rotor according to claim 1, characterized in that, After the high-pressure rotor (1) and the low-pressure rotor (2) have stopped rotating for a first period of time, it is necessary to rotate the high-pressure rotor (1) and the low-pressure rotor (2) again.

5. The method for rotating a steam turbine rotor according to claim 4, characterized in that, If the high-pressure rotor (1) and the low-pressure rotor (2) stop rotating for more than the first time period, the high-pressure rotor (1) and all the low-pressure rotors (2) are completely disengaged and lifted up. Lubricating oil is added to all the lower half bearings (3) for no less than the second time period. Then, the high-pressure rotor (1) and all the low-pressure rotors (2) are reset and rotated individually for a set number of revolutions.

6. The method for rotating a steam turbine rotor according to claim 5, characterized in that, After completing the set number of individual rotations, the low-pressure rotor (2) is connected in series using a coupling for overall rotation.

7. The method for rotating a steam turbine rotor according to claim 5, characterized in that, During the process of rotating the high-pressure rotor (1) and the low-pressure rotor (2), lubricating oil needs to be continuously added to the corresponding lower half bearing (3).

8. The method for rotating a steam turbine rotor according to claim 1, characterized in that, The multiple disc pins are evenly distributed on the low-pressure rotor (2) or the high-pressure rotor (1).

9. The method for rotating a steam turbine rotor according to claim 1, characterized in that, In step S8, the vehicle starts in the lowest gear and increases the output torque according to a set step size until it moves a second set distance.

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