Rotor positioning device and positioning method for steam turbine assembly

Abstract

The present invention relates to a rotor positioning device and positioning method for steam turbine assembly, belonging to the technical field of steam turbines, including a crane, the crane hoists the steam turbine rotor and blades through steel cables, the steam turbine cylinder body and stator are located directly below the steam turbine rotor and blades, and movable brackets are provided on the ground on both sides of the steam turbine cylinder body and stator, one of the movable brackets is provided with a laser displacement locator, and the other movable bracket is provided with a servo motor with a PLC controller, a shaft and a thrust plate. The present invention constructs a rotor flow distance measurement and thrust positioning system during the assembly process of the steam turbine, which mainly uses a laser displacement locator as a measuring unit, and uses the difference between the axial measured displacement and the designed displacement as an input signal, and then uses a PLC controller to drive the servo motor to drive the thrust plate to accurately position the steam turbine rotor in the axial direction. Compared with the traditional manual assembly method, the advantage is that it is faster, more accurate and more labor-saving to assemble the rotor during the assembly process.

Description

Technical Field

[0001] The invention relates to a rotor positioning device and a positioning method for steam turbine assembly, belonging to the technical field of steam turbines. Background Art

[0002] As a precision equipment composed of thousands of parts, the assembly quality of the steam turbine directly affects its subsequent operation stability and safety. Therefore, the steam turbine will be assembled before leaving the factory to check its assembly quality, and then disassembled into parts and sent to the site. After the equipment arrives at the site, it will be assembled again on site. After this assembly, it will be put into use. After several cycles of operation, it will be overhauled, disassembled and reassembled. Therefore, how to improve the assembly quality and assembly speed of the steam turbine has always been a technical problem that equipment manufacturers and on-site assembly teams want to solve. The traditional assembly method requires manual measurement of the axial flow clearance between the rotor and the cylinder, lifting, positioning, and then repeated iteration of this process until the adjustment is appropriate. The traditional process is time-consuming and has high technical requirements for assembly workers. Summary of the invention

[0003] The purpose of the present invention is to solve the deficiencies in the prior art and to provide a rotor positioning device and a positioning method for steam turbine assembly, which can assemble the rotor more quickly, more accurately and with less effort.

[0004] The present invention is achieved through the following technical solutions:

[0005] That is, a rotor positioning device for steam turbine assembly, including a crane, which hoists the steam turbine rotor and blades through steel cables. The steam turbine cylinder body and stator are located directly below the steam turbine rotor and blades. Movable brackets are provided on the ground on both sides of the steam turbine cylinder body and stator, one of the movable brackets is provided with a laser displacement locator, and the other movable bracket is provided with a servo motor with a PLC controller, a shaft and a thrust plate.

[0006] A further improvement of the present invention is that the laser displacement locator is connected to a servo motor with a PLC controller via a signal feedback cable.

[0007] The present invention also provides a method for positioning a rotor for steam turbine assembly, comprising the following steps:

[0008] S1: Fixing the movable bracket on the steam outlet side of the steam turbine: Move the movable bracket to the steam outlet side of the steam turbine cylinder, and preliminarily fix and position the pulley at the bottom end of the movable bracket;

[0009] S2: Fasten the laser displacement locator by magnetic force or bolts so that the height of the laser beam is higher than the turbine cylinder and stator;

[0010] S3: Fixing of the movable bracket on the steam inlet side of the steam turbine: The fixing method of the movable bracket on this side is similar to the positioning method of the movable bracket on the steam outlet side. According to the coaxial principle of the two movable brackets and the rotor, the movable bracket on the steam outlet side is moved to the side end of the turbine cylinder body and the stator. The vertical end face of the movable bracket is further adjusted to be parallel to the rotor end face through the dial indicator. The pulley at the bottom end of the movable bracket is tightened. Finally, the servo motor with a PLC controller, the shaft and the thrust plate are respectively fastened to the movable bracket;

[0011] S4: Wiring and testing: Use the signal feedback cable to connect the laser displacement locator to the servo motor with PLC controller, and then dot test the measurement function of the laser displacement locator and the action of the servo motor with PLC controller;

[0012] S5: Measurement and calculation: First, the rotor is hoisted by a crane and dropped to a height where the laser displacement locator laser can hit the rotor end face. According to the size requirements of the assembly drawing, the position of the suspended rotor is preliminarily located.

[0013] S6: Signal input and thrust positioning: Based on step S5, the rotor is lifted and the displacement difference is input into the PLC controller to make the thrust plate move axially, thereby driving the axial displacement of the rotor. Finally, after the laser displacement locator gives the final position signal, the servo motor stops applying axial force to the thrust plate, and the crane drops the rotor again to measure and calibrate the flow clearance between the first or second-stage rotor impeller and the partition. If it meets the design requirements of the drawing, the rotor dropping operation is completed.

[0014] The positioning device of the present invention constructs a set of rotor flow distance measurement and thrust positioning system during the steam turbine assembly process, mainly using a laser displacement locator as a measuring unit, using the difference between the axial measured displacement and the designed displacement as an input signal, and then using a PLC controller to drive a servo motor to drive the thrust plate to accurately position the turbine rotor in the axial direction. Compared with the traditional manual assembly method, the advantages are: it is faster, more accurate, and more labor-saving to assemble the rotor during the final assembly process.

[0015] A further improvement of the present invention is that in step S5, the method for preliminary positioning of the suspended rotor is specifically as follows: a position signal is input through a PLC controller, the servo motor drives the thrust plate to move horizontally, the rotor is dropped, the axial flow clearance between the rotor and the stator partition is measured, and the most reasonable rotor axial adjustment displacement is calculated based on the collected clearance between each stage of the impeller and the partition.

[0016] A further improvement of the present invention is that after step S6, the following steps are also included: theoretically, all parts of the steam turbine are processed normally according to the drawings. When processing or other problems occur, the steam seal of the partition is ground until it meets the system flow design requirements.

[0017] A further improvement of the present invention is that if a problem is found in the measurement and calculation in step S4, step S6 is paused, the partition that needs to be ground is lifted out by a crane, and then lifted back in after grinding, and then the rotor is assembled according to step S6.

[0018] A further improvement of the present invention is that in step S2, after the laser displacement locator is fastened by magnetic force or bolts, the movable bracket is further positioned using a dial indicator to ensure that the movable bracket is perpendicular to the ground, that is, the positioning surface of the laser displacement locator is parallel to the turbine cylinder body, to ensure that the laser beam and the rotor end face maintain a vertical relationship during assembly, and finally the movable bracket is completely fastened.

[0019] A further improvement of the present invention is that in step S3, after moving the movable bracket on the steam outlet side to the side end of the turbine cylinder body and the stator, the vertical end face of the movable bracket is further adjusted to be parallel to the rotor end face by a dial indicator, the pulley at the bottom end of the movable bracket is tightened, and finally the servo motor, shaft and thrust plate with a PLC controller are respectively fastened to the movable bracket.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The positioning device of the present invention constructs a set of rotor flow distance measurement and thrust positioning system during the steam turbine assembly process, mainly using a laser displacement locator as a measuring unit, using the difference between the axial measured displacement and the designed displacement as an input signal, and then using a PLC controller to drive a servo motor to drive the thrust plate to accurately position the turbine rotor in the axial direction. Compared with the traditional manual assembly method, the advantages are: it is faster, more accurate, and more labor-saving to assemble the rotor during the final assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of a specific implementation mode of the present invention.

[0024] In the figure: 1. Turbine cylinder and stator; 2. Turbine rotor and blades; 3. Movable bracket; 4. Laser displacement locator; 5. Servo motor with PLC controller; 6. Shaft; 7. Thrust plate; 8. Steel cable; 9. Crane; 10. Signal feedback cable. DETAILED DESCRIPTION

[0025] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0026] like Figure 1 A rotor positioning device for steam turbine assembly shown in the figure comprises a crane 9, which hoists the steam turbine rotor and blades 2 through a steel cable 8. The steam turbine cylinder body and stator 1 are located directly below the steam turbine rotor and blades 2. Movable brackets 3 are provided on the ground on both sides of the steam turbine cylinder body and stator 1. A laser displacement locator 4 is provided on one of the movable brackets 3, and a servo motor 5 with a PLC controller, a shaft 6 and a thrust plate 7 are provided on the other movable bracket 3. The laser displacement locator 4 is connected to the servo motor 5 with a PLC controller through a signal feedback cable 10.

[0027] The present invention also provides a method for positioning a rotor for steam turbine assembly, comprising the following steps:

[0028] S1: Fixing the movable bracket on the steam outlet side of the steam turbine: Move the movable bracket 3 to the steam outlet side of the steam turbine cylinder, and preliminarily fix and position the pulley at the bottom end of the movable bracket 3 at a suitable position;

[0029] S2: Fasten the laser displacement locator 4 at a suitable height by means of magnetic force or bolts, so that the height of the laser beam is higher than the turbine cylinder body and the stator 1, and further position the movable bracket 3 with a dial indicator to ensure that the movable bracket 3 is perpendicular to the ground, that is, the positioning surface of the laser displacement locator 4 is parallel to the turbine cylinder body, so as to ensure that the laser beam and the rotor end face maintain a vertical relationship during assembly, and finally, completely fasten the movable bracket 3. If necessary, auxiliary fastening can be carried out according to the on-site conditions;

[0030] S3: Fixing of the movable bracket on the steam inlet side of the steam turbine: The fixing method of the movable bracket 3 on this side is similar to the positioning method of the movable bracket 3 on the steam outlet side. According to the coaxial principle of the two movable brackets 3 and the rotor, the movable bracket 3 on the steam outlet side is moved to the side end of the steam turbine cylinder body and the stator 1. The vertical end face of the movable bracket 3 is further adjusted to be parallel to the rotor end face by the dial indicator. The pulley at the bottom end of the movable bracket 3 is tightened and necessary additional tightening work is performed. Finally, the servo motor 5 with a PLC controller, the shaft 6 and the thrust plate 7 are respectively fastened to the movable bracket 3;

[0031] S4: Wiring and testing: Use the signal feedback cable 10 to connect the laser displacement locator 4 and the servo motor 5 with the PLC controller, and then dot test the measurement function of the laser displacement locator 4 and the action of the servo motor 5 with the PLC controller;

[0032] S5: Measurement and calculation: First, the rotor is hoisted by the crane 9 and dropped to a height position where the laser of the laser displacement locator 4 can hit the rotor end face. According to the size requirements of the assembly drawing, the position of the suspended rotor is preliminarily positioned. The preliminary positioning method is: input the position signal through the PLC controller, let the servo motor drive the thrust plate 7 to move horizontally, drop the rotor, measure the axial flow clearance between the rotor and the stator partition, and calculate the most reasonable rotor axial adjustment displacement according to the collected clearance between each stage of the impeller and the partition;

[0033] S6: Signal input and thrust positioning: On the basis of step S5, the rotor is lifted and the displacement difference is input into the PLC controller to make the thrust plate 7 move axially, thereby driving the axial displacement of the rotor. Finally, after the laser displacement locator 4 gives the final position signal, the servo motor stops giving the thrust plate 7 an axial force, and the crane 9 drops the rotor again to measure and calibrate the flow clearance between the first-stage or second-stage rotor impeller and the partition. If it meets the design requirements of the drawing, the rotor dropping operation is completed. In theory, all parts of the steam turbine are processed normally according to the drawings, and there is no need to grind the partition. In addition, in the assembly of the steam turbine, the axial flow clearance between the rotor and the stator can be adjusted in one step. However, in actual operation, the steam seal of the partition may be ground due to processing or other problems until it meets the system flow design requirements.

[0034] S7: If a problem is found in the measurement and calculation in step S4, step S6 is paused, and the partition that needs to be ground is lifted out by the crane 9, and then lifted back in after grinding, and then the rotor is assembled according to step S6.

[0035] The positioning device of the present invention constructs a set of rotor flow distance measurement and thrust positioning system during the steam turbine assembly process, mainly using a laser displacement locator as a measuring unit, using the difference between the axial measured displacement and the designed displacement as an input signal, and then using a PLC controller to drive a servo motor to drive the thrust plate 7 to accurately position the turbine rotor in the axial direction. Compared with the traditional manual assembly method, the advantages are: it is faster, more accurate and more labor-saving to assemble the rotor during the final assembly process.

[0036] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0037] The terms "upper", "lower", "outer side", "inner side", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish the relative relationship in position if they exist, and do not need to be qualitative. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0038] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for positioning a rotor for steam turbine assembly, characterized in that: The turbine rotor is positioned using a positioning device, the positioning device comprising a crane (9), the crane (9) hoisting the turbine rotor and blades (2) via a steel cable (8), the turbine cylinder and stator (1) being located directly below the turbine rotor and blades (2), movable brackets (3) being provided on the ground on both sides of the turbine cylinder and stator (1), one of the movable brackets (3) being provided with a laser displacement positioner (4), and the other movable bracket (3) being provided with a servo motor (5) with a PLC controller, a shaft (6) and a thrust plate (7); the laser displacement positioner (4) and the servo motor (5) with a PLC controller are connected via a signal feedback cable (10); The positioning method comprises the following steps: S1: Fixing the movable bracket on the steam outlet side of the steam turbine: Move the movable bracket (3) to the steam outlet side of the steam turbine cylinder body, and perform preliminary fixing and positioning of the pulley at the bottom end of the movable bracket (3); S2: Fastening the laser displacement locator (4) by magnetic force or bolts so that the height of the laser beam is higher than the turbine cylinder body and the stator (1); S3: Fixing of the movable bracket on the steam inlet side of the steam turbine: The fixing method of the movable bracket (3) on this side is similar to the positioning method of the movable bracket (3) on the steam outlet side. According to the principle that the two movable brackets (3) are coaxial with the rotor, the movable bracket (3) on the steam inlet side is moved to the side end of the steam turbine cylinder body and the stator (1). The vertical end face of the movable bracket (3) is further adjusted to be parallel to the end face of the rotor by using a dial indicator. The pulley at the bottom end of the movable bracket (3) is tightened. Finally, the servo motor (5), shaft (6) and thrust plate (7) with a PLC controller are respectively fastened to the movable bracket (3); S4: Wiring and testing: Use the signal feedback cable (10) to connect the laser displacement locator (4) and the servo motor (5) with the PLC controller, and then dot test the measurement function of the laser displacement locator (4) and the operation of the servo motor (5) with the PLC controller; S5: Measurement and calculation: First, the rotor is hoisted by the crane (9) and lowered to a height position where the laser of the laser displacement locator (4) can hit the rotor end face, and the position of the suspended rotor is preliminarily located according to the size requirements of the assembly drawing; S6: Signal input and thrust positioning: Based on step S5, the rotor is lifted and the displacement difference is input into the PLC controller, so that the thrust plate (7) moves axially, thereby driving the axial displacement of the rotor. Finally, after the laser displacement locator (4) gives the final position signal, the servo motor stops applying axial force to the thrust plate (7), and the crane (9) drops the rotor again. The flow clearance between the first or second stage rotor impeller and the partition is measured and checked. If it meets the design requirements of the drawing, the rotor dropping operation is completed.

2. A method for positioning a rotor for steam turbine assembly according to claim 1, characterized in that: The method for preliminary positioning of the suspended rotor in step S5 is specifically as follows: inputting a position signal through a PLC controller, allowing the servo motor to drive the thrust plate (7) to move horizontally, dropping the rotor, measuring the axial flow clearance between the rotor and the stator partition, and calculating the most reasonable rotor axial adjustment displacement based on the collected clearance between each stage of the impeller and the partition.

3. A method for positioning a rotor for steam turbine assembly according to claim 1, characterized in that: The following steps are also included after step S6: theoretically, all parts of the steam turbine are processed normally according to the drawings. When processing or other problems occur, the steam seal of the partition is ground until it meets the system flow design requirements.

4. A method for positioning a rotor for steam turbine assembly according to claim 3, characterized in that: If a problem is found in the measurement and calculation in step S4, step S6 is suspended, and the partition that needs to be ground is lifted out by the crane (9), and then lifted back in after grinding, and then the rotor is assembled according to step S6.

5. A method for positioning a rotor for steam turbine assembly according to claim 1, characterized in that: In step S2, after the laser displacement locator (4) is fastened by magnetic force or bolts, the movable bracket (3) is further positioned using a dial indicator to ensure that the movable bracket (3) is perpendicular to the ground, that is, the positioning surface of the laser displacement locator (4) is parallel to the turbine cylinder body, to ensure that the laser beam and the rotor end face maintain a vertical relationship during assembly, and finally the movable bracket (3) is completely fastened.

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