A load distribution method for a steam turbine generator

Abstract

The application provides a load distribution method for a steam turbine generator, which comprises the following steps: setting a load measuring point and a displacement measuring point respectively; repeatedly testing the load and initially adjusting the thickness of the foot pad corresponding to the stable measuring point; adjusting the jack at the stable measuring point according to the load table of the steam turbine generator; testing the load of each jack at the adjustment measuring point while maintaining the jack at the stable measuring point; and adjusting the thickness of the foot pad corresponding to the adjustment measuring point again according to the test result. The load measuring point and the displacement measuring point corresponding to the foot pad are set, the load of the steam turbine generator stator part is adjusted at each load measuring point and displacement point, the thickness of the corresponding foot pad is adjusted, and the thickness of the foot pad of the steam turbine generator end cover part is adjusted, so that the load of the generator after the steam turbine unit maintenance is quickly leveled, and the vibration of the generator is eliminated.

Description

Technical Field

[0001] This invention belongs to the field of generator load leveling technology, and particularly relates to a load distribution method for steam turbine generators. Background Technology

[0002] A steam turbine generator is a type of synchronous generator, mainly composed of a rotor and a stator. In thermal power plants, the steam turbine generator is one of the three key pieces of equipment. It is an electrical device that uses a steam turbine as the prime mover to drive the rotor to rotate, converting mechanical energy into electrical energy using the principle of electromagnetic induction.

[0003] During the operation of a steam turbine generator, excessive vibration of the turbine generator bearing housing may accelerate the wear of certain components inside the turbine generator, resulting in fatigue damage to the bearing shells, loosening and cracking of the secondary grouting of the foundation, and cracking of the cooling water pipes of the generator stator hydrogen cooler. Under certain special operating conditions, it may even cause accidents such as the turbine generator set tripping, which seriously affects the safety and economy of the unit.

[0004] During major overhauls of the generator set, rotor center adjustments are frequently necessary due to foundation settlement and other factors. Because the turbine generator set contains equipment such as the main oil pump, adjustments are complex. To ensure the maintenance schedule, most maintenance personnel focus the larger adjustments on the turbine generator stator itself. During these adjustments, the stator's base shims inevitably become disordered. Since the sides and center of the turbine generator are not integrally formed, and there is a certain degree of imbalance on both sides, these factors can lead to significant deviations in the load distribution of the turbine generator stator after maintenance. Given that turbine generators can weigh hundreds of tons, improper installation and maintenance can cause significant vibrations even under minor excitation forces during operation. Summary of the Invention

[0005] To address the problem described in the background art where improper installation and maintenance of steam turbine generators result in significant vibrations even under minor excitation forces during operation, this invention proposes the following technical solution:

[0006] A load sharing method for a steam turbine generator, comprising:

[0007] Load measurement points and deviation measurement points are set up separately, and a dial gauge is installed at each deviation measurement point;

[0008] Multiple load measurement points are selected as stable measurement points, and the remaining load measurement points are selected as adjustment measurement points;

[0009] Install jacks with pressure gauges at each stable measurement point;

[0010] Repeat the load test and make an initial adjustment to the thickness of the foot pads corresponding to the stable measurement points based on the test results;

[0011] The jack at the stable measurement point is pressurized and adjusted according to the load table of the steam turbine generator;

[0012] The jack equipped with a pressure gauge is installed at the adjustment and measurement point;

[0013] Maintain the state of the jack at the stable measurement point, and at the same time perform load tests on each of the jacks at the adjustment measurement point;

[0014] Based on the test results, the thickness of the corresponding foot pads at the adjusted measurement points is readjusted.

[0015] The load test includes applying the same pressure value to each of the jacks.

[0016] The pressurization operation is repeated multiple times until the lowest height among the load measurement points is raised to the set height.

[0017] Record the data of each pressure gauge when the load measurement point with the lowest height is raised to the set height each time, and form a pressure gauge array;

[0018] Record the data of each dial gauge when the lowest height among the deviation measurement points is increased to a set height each time, and form a dial gauge array;

[0019] Return each jack and dial indicator to its initial state.

[0020] Furthermore, during the initial adjustment process, it is necessary to first select the two groups with the smallest data deviation in the dial gauge array, and then adjust the thickness of the base pad at the corresponding position according to the average of the data differences at the positions corresponding to the stable measurement points in the two groups of dial gauge arrays.

[0021] Furthermore, each of the offset measurement points is distributed along the edge of the steam turbine generator, and the offset measurement points are respectively located on one of two mutually parallel arcs.

[0022] Furthermore, the load measurement points are located on two parallel straight lines, and there is a one-to-one correspondence between the load measurement points on each straight line.

[0023] Furthermore, when adjusting the thickness of the corresponding foot pad at the adjustment measurement point, the load test can be repeated multiple times while maintaining the jack at the stable measurement point until the data difference between each dial indicator is less than the set deviation range.

[0024] Furthermore, when pressurizing the jack at the stable measurement point according to the load table, the pressurization value of the jack is equal to the average value of the pressure gauge array formed during the first load measurement process minus the load value at the turbine generator end in the load table.

[0025] Beneficial effects: This invention sets load measurement points and offset measurement points that correspond one-to-one with the base pads. After adjusting the stability of the turbine generator stator by testing the load at each load measurement point and offset point, the thickness of the corresponding base pads is stabilized and the thickness of the base pads on the turbine generator end cover is adjusted. This allows for rapid completion of generator load leveling after turbine unit overhaul, thereby eliminating generator vibration. Attached Figure Description

[0026] Figure 1 A flowchart illustrating a load distribution method for a steam turbine generator according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram showing the placement of a dial gauge during a load test according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the present invention will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0029] It should be understood that the terms “center,” “upper,” “lower,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this patent.

[0030] Figure 1 This is a flowchart of a load distribution method for a steam turbine generator according to an embodiment of the present invention.

[0031] To better describe the entire load distribution process, a brief description of the turbine generator's structure is provided below. The turbine generator has a three-section structure: end caps at both ends and the generator stator in the middle. One end cap is the steam end, which is connected to the turbine. The other end cap is the excitation end, which is connected to the exciter.

[0032] Reference Figure 1A load distribution method for a steam turbine generator according to an embodiment of the present invention includes:

[0033] S010. Load measurement points and deviation measurement points are set on the steam turbine generator, and a dial indicator is installed at each deviation measurement point.

[0034] Specifically, in this step, after the maintenance of the steam turbine generator is completed, load measurement points and offset measurement points are set at the locations near the base shims of the steam turbine generator. In this embodiment, there are eight base shims for the steam turbine generator, each located near the edge of the base plate supporting the generator, and the eight base shims are evenly distributed to support the generator. Correspondingly, there are eight load measurement points and eight offset measurement points, each offset measurement point located on the steam turbine generator, and each offset measurement point is situated on one of two parallel arcs. In other embodiments, the number of load measurement points and offset measurement points is the same as the number of base shims, and the number can be adjusted according to different models of steam turbine generators.

[0035] Each load measurement point is located on the base plate supporting each foot of the turbine generator, and each load measurement point is located on one of the straight lines L1 and L2 near the edge. Straight lines L1 and L2 are parallel to each other, and each line L1 and L2 has four load measurement points. The load measurement points on lines L1 and L2 correspond one-to-one. Offset measurement points are located on the two sides of the turbine generator adjacent to the bottom surface, and each offset measurement point corresponds to one load measurement point. Each offset measurement point is equipped with a dial indicator to monitor the offset during load testing. The percentage value of each load measurement point indirectly reflects the thickness of the foot shims at the corresponding location.

[0036] S020. Select multiple load measurement points as stable measurement points, and the remaining load measurement points as adjustment measurement points.

[0037] Figure 2 This is a schematic diagram showing the placement of a dial gauge during a load test according to an embodiment of the present invention.

[0038] Specifically, refer to Figure 2 The load measurement points on line L1, arranged from left to right as shown in the diagram, are: the sixth load measurement point, the second load measurement point, the fourth load measurement point, and the eighth load measurement point. The load measurement points on line L2, arranged from left to right as shown in the diagram, are: the fifth load measurement point, the first load measurement point, the third load measurement point, and the seventh load measurement point. Based on the load testing requirements, several load measurement points among the eight that can stabilize the entire turbine generator are selected as stable measurement points.

[0039] Preferably, in this embodiment, the first load measurement point, the second load measurement point, the third load measurement point, and the fourth load measurement point are selected as stability measurement points. Each stability measurement point is located on the stator section of the turbine generator. The lines connecting the stability measurement points form a rectangle to stabilize the entire turbine generator during the load testing phase after the jacks are installed.

[0040] S030. Install jacks with pressure gauges at each stable measuring point.

[0041] S040. Repeat the load test and make an initial adjustment to the thickness of the foot pad corresponding to the stable measurement point based on the test results.

[0042] Specifically, before conducting load tests, each dial gauge and pressure gauge needs to be zeroed to facilitate subsequent data recording. After multiple load tests are completed, the thickness of the corresponding foot pads at each stable measurement point is initially adjusted based on the test results.

[0043] Each load test includes:

[0044] S041. Apply the same pressure value to each of the jacks;

[0045] S042. Repeat the above pressurization operation until the lowest height among the load measurement points is raised to the set height;

[0046] S043. Record the data of each pressure gauge when the set height is increased at the lowest of the load measurement points each time, and form a pressure gauge array;

[0047] S044. Record the data of each dial gauge when the lowest height among the deviation measurement points is raised to a set height each time, and form a dial gauge array;

[0048] Specifically, each pressure gauge array includes the pressure gauge reading at each stable measurement point, and each dial gauge array includes the dial gauge reading at each deviation measurement point. The pressure gauge reading reflects the load on the turbine generator at that measurement point, and the dial gauge reading reflects the horizontal relationship between different points on the turbine generator's base.

[0049] During the initial adjustment process, it is necessary to select the two sets of data with the closest dial gauge array from each load test result and perform average processing. After the average processing is completed, the thickness of the base pad corresponding to each stable measurement point needs to be adjusted according to the average processing result.

[0050] After the initial adjustment, the pressure on each jack is released, and the thickness of the shims at each stable measurement point is sufficient to support the bottom of the turbine generator stator section and maintain stability. Due to the influence of pipeline forces, the force required to lift the generator deviates from the value in the generator load distribution table. Furthermore, the stator base of the three-section generator exhibits a tilting phenomenon due to various factors (the stator section of the turbine generator has an arched top, and the end cap section has arched feet; after the stator section stabilizes, the two ends of the turbine generator end cap may become uneven). Therefore, after the initial adjustment, it is still necessary to continue adjusting the thickness of the shims at the end cap section.

[0051] S050. Adjust the pressure of the jack at the stable measurement point according to the load table of the steam turbine generator.

[0052] Specifically, in this step, each jack at the stable measurement point needs to be pressurized according to the turbine generator load gauge (factory-set load value) until the load of each jack is equal to the rated load in the load gauge. The pressurization value of each jack is equal to the average value of each pressure gauge array during the initial adjustment process minus the rated load.

[0053] S060. Install the jack with a pressure gauge at the adjustment measurement point;

[0054] S070. Maintain the state of the jack at the stable measurement point, and at the same time perform load tests on each of the jacks at the adjustment measurement point.

[0055] Specifically, in this step, the jacks at each stable measurement point need to maintain the state after pressure adjustment, and the jacks at each measurement point need to undergo the same load test process as in steps S041 to S044.

[0056] S080. Based on the test results, readjust the thickness of the corresponding foot pad at the adjusted measurement point.

[0057] Specifically, in this step, after stabilizing the stator section of the turbine generator and completing multiple load tests, the two sets of data closest in the dial gauge array are averaged. Based on the averaged dial gauge data, the thickness of the base shims corresponding to the adjusted measurement points is adjusted. Throughout this process, the thickness of the base shims corresponding to the stabilizing measurement points remains constant. The load tests are performed at least twice, with the specific number determined by the data in the dial gauge array. The load test can be stopped when the data corresponding to the same offset measurement point in the dial gauge array is less than the rated error value.

[0058] In summary, this invention, by setting load measurement points and offset measurement points that correspond one-to-one with the base pads, uses load measurements to adjust the stability of the turbine generator stator at each load measurement point and offset point, stabilizes the thickness of the corresponding base pads, and adjusts the thickness of the base pads on the turbine generator end cover, thus quickly completing the generator load leveling after turbine unit maintenance and eliminating generator vibration.

[0059] The foregoing has described specific embodiments of the invention. Other embodiments are within the scope of the appended claims.

[0060] The terms “exemplary,” “example,” etc., used throughout this specification mean “serving as an example, instance, or illustration” and do not imply “preferred” or “advantageous” than other embodiments. Detailed descriptions are included for the purpose of providing an understanding of the described techniques. However, these techniques can be practiced without these detailed descriptions. In some instances, well-known structures and apparatuses are shown in block diagram form to avoid obscuring the concepts of the described embodiments.

[0061] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0062] The foregoing description of this specification is provided to enable any person skilled in the art to implement or use the content of this specification. Various modifications to the content of this specification will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of protection of this specification. Therefore, this specification is not limited to the examples and designs described herein, but is consistent with the widest scope of the principles and novel features disclosed herein.

Claims

1. A load distribution method for a steam turbine generator, characterized in that, The load allocation method includes: Load measurement points and deviation measurement points are set up separately, and a dial gauge is installed at each deviation measurement point; Multiple load measurement points are selected as stable measurement points, and the remaining load measurement points are selected as adjustment measurement points; Install jacks with pressure gauges at each stable measurement point; Repeat the load test and make an initial adjustment to the thickness of the foot pads corresponding to the stable measurement points based on the test results; The jack at the stable measurement point is pressurized and adjusted according to the load table of the steam turbine generator; The jack equipped with a pressure gauge is installed at the adjustment and measurement point; Maintain the state of the jack at the stable measurement point, and at the same time perform load tests on each of the jacks at the adjustment measurement point; Based on the test results, the thickness of the corresponding foot pads at the adjusted measurement points was readjusted. Each load measurement point is located on the base plate supporting each foot of the turbine generator, and each load measurement point is located on one of the straight lines L1 and L2 near the edge. The load measurement points on straight line L1, from left to right, are: the sixth load measurement point, the second load measurement point, the fourth load measurement point, and the eighth load measurement point. The load measurement points on straight line L2, from left to right, are: the fifth load measurement point, the first load measurement point, the third load measurement point, and the seventh load measurement point. The first load measurement point, the second load measurement point, the third load measurement point, and the fourth load measurement point are selected as stable measurement points. Each stable measurement point is located on the stator part of the turbine generator, and the lines connecting the stable measurement points form a rectangle.

2. The load distribution method for a steam turbine generator according to claim 1, characterized in that, The load test includes applying the same pressure value to each of the jacks; The pressurization operation is repeated multiple times until the lowest height among the load measurement points is raised to the set height. Record the data of each pressure gauge when the load measurement point with the lowest height is raised to the set height each time, and form a pressure gauge array; Record the data of each dial gauge when the lowest height among the deviation measurement points is increased to a set height each time, and form a dial gauge array; Return each jack and dial indicator to its initial state.

3. The load distribution method for a steam turbine generator according to claim 2, characterized in that, During the initial adjustment process, it is necessary to first select the two groups with the smallest data deviation in the dial gauge array, and then adjust the thickness of the base pad at the corresponding position according to the average of the data difference between the stable measurement points in the two groups of dial gauge arrays.

4. A load distribution method for a steam turbine generator according to claim 2, characterized in that, Each of the offset measurement points is distributed along the edge of the steam turbine generator, and each offset measurement point is located on one of two mutually parallel arcs.

5. A load distribution method for a steam turbine generator according to claim 4, characterized in that, The load measurement points are located on two parallel straight lines, and there is a one-to-one correspondence between the load measurement points on the two straight lines.

6. A load distribution method for a steam turbine generator according to claim 5, characterized in that, When adjusting the thickness of the corresponding foot pad at the adjustment measurement point, while maintaining the jack at the stable measurement point, repeat the load test multiple times until the data difference between each dial indicator is less than the set deviation range.

7. A load distribution method for a steam turbine generator according to claim 5, characterized in that, When pressurizing the jack at the stable measurement point according to the load table, the pressurization value of the jack is equal to the average value of the pressure gauge array formed during the first load measurement process minus the load value at the end of the turbine generator in the load table.

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