A method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator

Abstract

The present invention discloses a method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator, comprising the following steps: measuring the static deflection of the rotor, installing and positioning the end cap, installing the rotor, and measuring and adjusting the rotor position. This method optimizes the method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator, resolving the difficulty of accurately measuring the air gap between the stator and rotor of some steam turbine generators. It also improves the accuracy of the measured data, facilitates the measurement and adjustment of the air gap between the stator and rotor during installation of a steam turbine generator set, and helps shorten the installation period of the steam turbine generator set.

Description

Technical Field

[0001] The invention relates to the field of steam turbine generator installation, and in particular to a method for measuring and adjusting the air gap between a stator and a rotor of a steam turbine generator. Background Art

[0002] The physical gap between a generator's stator and rotor is called the air gap, and its size directly affects generator performance. Theoretically, to reduce the generator's no-load current and improve its power factor, the air gap should be as small as possible. However, an excessively small air gap can make generator assembly, air gap measurement, and adjustment difficult. Furthermore, an uneven air gap can increase the generator's vibration and noise, and in severe cases, can lead to quality issues such as increased temperature, bearing damage, and bore scraping. When installing a steam turbine generator, it's crucial to measure and adjust the air gap to ensure uniformity in all directions. Typically, the air gap between the stator and rotor is determined by directly measuring the distance from the outer cylindrical surface of the rotor body to the inner circumference of the stator core. However, in practice, due to limitations in operating space and measurement methods, this air gap is not easily and accurately measured. Summary of the Invention

[0003] The present invention provides a method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator. The method is implemented by the following process steps:

[0004] S1. Measure the static deflection of the rotor: Place the turbine generator rotor naturally on the bracket, measure the center coordinates of the outer cylindrical surfaces at both ends of the rotor body corresponding to the ends of the generator stator core, and measure the center coordinates of the pillow blocks at both ends of the rotor corresponding to the end covers; calculate the vertical difference between the center of the outer cylindrical surface of the steam end body and the center of the outer cylindrical surface of the steam end pillow block, record it as A, and calculate the vertical difference between the center of the outer cylindrical surface of the excitation end body and the center of the outer cylindrical surface of the excitation end pillow block, record it as B;

[0005] S2. Install and position the end covers: After the generator stator is placed at the workstation, install the end covers at both ends of the stator. Use the line connecting the center of the inner cylindrical surface of the steam end of the stator core and the center of the inner cylindrical surface of the excitation end of the core as the reference line, that is, the core axis. Measure the horizontal and vertical deviations of the center of the inner cylindrical surface of the end covers at both ends relative to the reference line. Adjust the position of the end covers so that the horizontal deviation is 0 and the vertical deviation value is the same as A and B calculated in S1. After adjusting the position of the end covers, locate the installation positions of the end covers at both ends.

[0006] S3. Install the rotor: After removing the end covers, insert the turbine generator rotor into the stator chamber, place the shaft journals at both ends of the rotor on the bearings at both ends, and reinstall the end covers at both ends to return them to the installation position in S2;

[0007] S4. Adjust the rotor position: Measure the distance from the outer cylindrical surface of the rotor steam end pillow block to the inner cylindrical surface of the steam end cover, and measure four positions in total, up, down, left and right. According to the measured values, adjust the position of the rotor steam end pillow block so that the values ​​of the relative points are equal; use the same method to measure and adjust the position of the rotor excitation end pillow block.

[0008] In the above-mentioned method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator, in said S1, the center coordinates of the outer cylindrical surface of the steam end of the rotor body, the outer cylindrical surface of the excitation end of the rotor body, the outer cylindrical surface of the steam end pillow block, and the outer cylindrical surface of the excitation end pillow block are measured, which are calculated by fitting after measuring the spatial coordinates of the above-mentioned positions of the rotor.

[0009] In the above-mentioned method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator, in S1, the vertical difference A between the center of the outer cylindrical surface of the steam end body and the center of the outer cylindrical surface of the steam end pillow block, and the vertical difference B between the center of the outer cylindrical surface of the excitation end body and the center of the outer cylindrical surface of the excitation end pillow block can also be obtained by theoretically calculating the rotor deflection.

[0010] In the above method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator, in S2, the positioning of the end covers at both ends can be achieved by installing limit blocks on the stator or machining positioning pin holes on the end covers and the stator and installing positioning pins.

[0011] In the above-mentioned method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator, in said S4, when measuring the distance from the outer cylindrical surface of the steam end pillow block to the inner cylindrical surface of the steam end end cover, the values ​​at the upper left, lower left, upper right, and lower right positions can also be measured, or all eight positions can be measured; the same is true when measuring the excitation end.

[0012] By using the above method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator, the vertical deviation of the center of the inner cylindrical surface of the end covers at both ends relative to the axis of the stator core is firstly maintained consistent with the static deflection of the rotor. Then, by measuring and adjusting the distance from the outer cylindrical surface of the pillow blocks at both ends of the rotor to the inner cylindrical surface of the end covers at both ends, the distance from the outer cylindrical surface at both ends of the rotor body to the inner cylindrical surface at both ends of the stator core, i.e., the stator and rotor air gap, is indirectly measured and adjusted, thereby realizing the indirect measurement and adjustment of the air gap size between the stator and rotor of the steam turbine generator.

[0013] The beneficial effects of the present invention are:

[0014] The present invention optimizes the method for measuring the air gap between the stator and rotor of a steam turbine generator, solves the problem that the air gap between the stator and rotor of some steam turbine generators cannot be accurately measured, and also improves the accuracy of the measurement data. It provides convenient conditions for measuring and adjusting the air gap between the stator and rotor during on-site installation of the steam turbine generator set, and helps to shorten the installation period of the steam turbine generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the generator rotor placement.

[0016] Figure 2 Schematic diagram of installing the end cover for the generator stator.

[0017] Figure 3 Schematic diagram of installing the rotor and end covers for the generator.

[0018] Figure 4 Schematic diagram of the distance measurement between the pillow block and the end cover.

[0019] Description of the marks in the figure:

[0020] 1-generator rotor; 2-steam end journal; 3-excitation end journal; 4-body steam end;

[0021] 5-Excitation end of body; 6-Steam end pillow block; 7-Excitation end pillow block; 8-Steam end cover;

[0022] 9-excitation end cover; 10-core steam end; 11-core excitation end; 12-steam end bearing;

[0023] 13-excitation end bearing; 14-generator stator; 15-rotor bracket. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] The present invention provides a method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator. The method is implemented by the following process steps:

[0026] S1. Measure the static deflection of the rotor: Figure 1 、 Figure 3 As shown, the turbine generator rotor 1 is naturally placed on the bracket 15, and the supporting positions of the rotor 1 are the steam end journal 2 and the excitation end journal 3. The center coordinates of the outer cylindrical surface of the steam end 4 of the rotor body and the outer cylindrical surface of the excitation end 5 of the rotor body are measured. These two positions correspond to the positions of the steam end 10 and the excitation end 11 of the generator stator 14 after the rotor is installed; the center coordinates of the outer cylindrical surface of the steam end pillow block 6 and the outer cylindrical surface of the excitation end pillow block 7 of the rotor 1 are measured. These two positions correspond to the positions of the steam end cover 8 and the excitation end cover 9 of the generator after the rotor 1 is installed; the difference between the center of the outer cylindrical surface of the steam end 4 of the rotor body and the center of the outer cylindrical surface of the steam end pillow block 6 in the vertical direction is calculated and recorded as A, and the difference between the center of the outer cylindrical surface of the excitation end 5 of the rotor body and the center of the outer cylindrical surface of the excitation end pillow block 7 in the vertical direction is calculated and recorded as B;

[0027] S2. Install the end cover and position it: Figure 2 As shown, after the generator stator 14 is placed at the work station, the steam end cover 8 and the excitation end cover 9 are respectively installed on both sides of the stator 14 and temporarily fixed; with the line connecting the center of the inner cylindrical surface of the iron core steam end 10 and the center of the inner cylindrical surface of the iron core excitation end 11 as the reference line, that is, the iron core axis, the horizontal deviation and vertical deviation of the center of the inner cylindrical surface of the steam end cover 8 relative to the iron core axis, and the horizontal deviation and vertical deviation of the center of the inner cylindrical surface of the excitation end cover 9 relative to the iron core axis are measured respectively; the positions of the steam end cover 8 and the excitation end cover 9 in the horizontal and vertical directions are adjusted so that the horizontal deviation is 0 and the vertical deviation value is the same as A and B calculated in S1; after fixing the positions of the steam end cover 8 and the excitation end cover 9, the installation positions of the steam end cover 8 and the excitation end cover 9 are positioned respectively;

[0028] S3. Install the rotor: Figure 3 As shown, after removing the steam end cover 8 and the excitation end cover 9, the turbine generator rotor 1 is inserted into the stator 14 bore. At this time, the steam end journal 2 and the excitation end journal 3 of the rotor 1 are placed on the steam end bearing 12 and the excitation end bearing 13 respectively. The rotor 1 and the stator 14 are not in contact. The steam end cover 8 and the excitation end cover 9 are installed again, and the steam end cover 8 and the excitation end cover 9 are returned to the installation position in S2.

[0029] S4. Adjust the rotor position: Figure 3 、 Figure 4 As shown, the distance from the outer cylindrical surface of the steam-end pillow block 6 of the rotor 1 to the inner cylindrical surface of the steam-end end cover 8 is measured at a total of four points: top, bottom, left, and right. Based on the measured values, the generator stator 14 and the steam-end end cover 8 are kept stationary, and the position of the steam-end pillow block 6 of the rotor 1 is adjusted by adjusting the position of the steam-end bearing 12 so that the values ​​at the relative points are equal, that is, the upper value is equal to the lower value, and the left value is equal to the right value; the position of the excitation-end pillow block 7 of the rotor 1 is measured and adjusted in the same way.

[0030] In this embodiment, a method for measuring and adjusting the air gap between the stator and rotor of a steam turbine generator is developed according to a process. First, the vertical deviation of the inner cylindrical surface of the end caps at both ends relative to the axis of the iron core is kept consistent with the static deflection of the rotor. Then, by measuring and adjusting the distance from the outer cylindrical surface of the pillow blocks at both ends of the rotor to the inner cylindrical surface of the end caps at both ends, the distance from the outer cylindrical surface of the rotor body at both ends to the inner cylindrical surface of the stator core at both ends, that is, the stator and rotor air gap, is indirectly measured and adjusted. This realizes the indirect measurement and adjustment of the air gap size between the stator and rotor of the steam turbine generator, making the air gap of the stator and rotor uniform in all directions.

[0031] Specific implementation method 2: Figure 1As shown, this embodiment further limits S1 described in the specific embodiment 1. In this embodiment, the center coordinates of the outer cylindrical surface of the steam end 4 of the rotor 1 body, the outer cylindrical surface of the excitation end 5 of the body, the outer cylindrical surface of the steam end shaft seat 6, and the outer cylindrical surface of the excitation end shaft seat 7 measured in S1 are calculated by measuring the spatial coordinates of the above-mentioned positions of the rotor 1 and then fitting.

[0032] In this embodiment, a method for measuring the center coordinates of the positions at both ends of the rotor body and the positions of the pillow blocks on both sides of the rotor is determined.

[0033] Specific implementation method three: Figure 1 As shown, this embodiment further limits S1 described in the specific embodiment 1. In this embodiment, in S1, the vertical difference A between the center of the outer cylindrical surface of the steam end 4 of the rotor 1 body and the center of the outer cylindrical surface of the steam end shaft seat 6, and the vertical difference B between the center of the outer cylindrical surface of the excitation end 5 of the rotor body and the center of the outer cylindrical surface of the excitation end shaft seat 7 can also be obtained by theoretical calculation.

[0034] In this embodiment, another method for obtaining the vertical difference between the centers of the two ends of the rotor body and the centers of the pillow blocks on both sides of the rotor is provided.

[0035] Specific implementation method four: Figure 2 As shown, this embodiment further limits S2 described in the specific embodiment 1. In this embodiment, in the S2, the positioning of the steam end cover 8 and the excitation end cover 9 can be achieved by installing a limit block on the stator 14 or processing positioning pin holes on the steam end cover 8, the excitation end cover 9 and the stator 14 and installing positioning pins.

[0036] In this embodiment, a method for positioning the end covers is provided so that the vertical deviation of the inner cylindrical surfaces of the end covers at both ends relative to the core axis is consistent with the static deflection of the rotor.

[0037] Specific implementation method five: Figure 3 As shown, this embodiment further limits S4 described in the specific embodiment 1. In this embodiment, in S4, when measuring the distance from the outer cylindrical surface of the excitation end pillow block 6 to the inner cylindrical surface of the excitation end cover 8, the values ​​of the four positions of upper left, lower left, upper right, and lower right can also be measured, or all eight positions can be measured.

[0038] In this embodiment, a method for measuring the distance between the outer cylindrical surface of the rotor pillow block and the inner cylindrical surface of the end cover is determined.

[0039] The present invention establishes a method for measuring and adjusting the stator and rotor air gap of a steam turbine generator according to a process, converting the stator and rotor air gap inside the generator, which is difficult to accurately measure, into the gap between the outer cylindrical surface of the rotor pillow block and the inner cylindrical surface of the end cover, which is easy to accurately measure. This realizes the indirect measurement and adjustment of the stator and rotor air gap, provides convenient conditions for on-site installation of the steam turbine generator, and also improves the accuracy of the measurement data.

[0040] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the claims and their equivalents.

Claims

1. A method for adjusting the air gap between a stator and a rotor of a steam turbine generator, comprising the following steps: S1. Measuring the static deflection of the rotor: placing the turbine generator rotor (1) naturally on the bracket (15), measuring the center coordinates of the outer cylindrical surface of the steam end (4) of the rotor (1) and the outer cylindrical surface of the excitation end (5) of the rotor (1), measuring the center coordinates of the outer cylindrical surface of the steam end shaft seat (6) of the rotor (1) and the outer cylindrical surface of the excitation end shaft seat (7); calculating the difference between the center of the outer cylindrical surface of the steam end (4) of the rotor and the center of the outer cylindrical surface of the steam end shaft seat (6) in the vertical direction, recorded as A, calculating the difference between the center of the outer cylindrical surface of the excitation end (5) of the rotor and the center of the outer cylindrical surface of the excitation end shaft seat (7) in the vertical direction, recorded as B; S2. Install and position the end covers: After the generator stator (14) is placed at the workstation, install the steam end cover (8) and the excitation end cover (9) on both sides of the stator (14) respectively; take the line connecting the center of the inner cylindrical surface of the iron core steam end (10) and the center of the inner cylindrical surface of the iron core excitation end (11) as the reference line, i.e., the iron core axis, and measure the horizontal deviation and vertical deviation of the center of the inner cylindrical surface of the steam end cover (8) and the center of the inner cylindrical surface of the excitation end cover (9) relative to the iron core axis respectively; adjust the horizontal and vertical positions of the steam end cover (8) and the excitation end cover (9) so that the horizontal deviation is 0 and the vertical deviation value is the same as A and B calculated in S1; and position the installation positions of the steam end cover (8) and the excitation end cover (9) respectively; S3. Install the rotor: After removing the steam end cover (8) and the excitation end cover (9), insert the turbine generator rotor (1) into the stator (14) chamber. At this time, the steam end journal (2) and the excitation end journal (3) of the rotor (1) are placed on the steam end bearing (12) and the excitation end bearing (13) respectively. Install the steam end cover (8) and the excitation end cover (9) again according to the positioning position in S2; S4. Measure and adjust the rotor position: Measure the distance from the outer cylindrical surface of the steam end shaft block (6) of the rotor (1) to the inner cylindrical surface of the steam end cover (8). Measure four points in total, top, bottom, left, and right. Adjust the position of the steam end shaft block (6) of the rotor (1) based on the measured values ​​so that the values ​​at the relative points are equal. Use the same method to measure and adjust the position of the excitation end shaft block (7) of the rotor (1).

2. The method for adjusting the air gap between the stator and rotor of a steam turbine generator according to claim 1, wherein: In the above-mentioned S2, the installation positions of the steam end cover (8) and the excitation end cover (9) are positioned by installing a limit block on the stator (14) or machining positioning pin holes on the steam end cover (8), the excitation end cover (9) and the stator (14) and installing positioning pins.

3. The method for adjusting the air gap between the stator and rotor of a steam turbine generator according to claim 1, wherein: In said S4, when measuring the distance from the outer cylindrical surface of the steam end shaft table (6) to the inner cylindrical surface of the steam end cover (8), the values ​​at the upper left, lower left, upper right and lower right positions are measured.

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