A monitoring module and monitoring method for axial thrust of steam turbine

Abstract

The present invention discloses a monitoring module and a monitoring method for the axial thrust of a steam turbine, including a shoe seat, wherein a plurality of thrust shoes are evenly installed in the shoe seat along the circumferential direction, an outer circular groove is provided on the outer surface of the thrust shoe, an inner circular groove is provided at the lower middle part of the outer circular groove, a force measuring sensitive element is provided in the outer circular groove, an element buffer assembly is distributed on the inner ring surface of the inner circular groove, the element buffer assembly includes a plurality of accommodating grooves evenly provided on the inner ring surface of the inner circular groove along the circumferential direction, a buffer wheel is movably provided in the accommodating groove, mounting grooves are symmetrically distributed on both sides of the accommodating groove, the mounting groove is provided in the thrust shoe, and is interconnected with the accommodating groove, a guide rod is passed through the mounting groove, one end of the guide rod is fixed on the groove wall of the mounting groove, and the other end is passed through the inside of one end of the movable rod, the movable rod is passed through the inside of the buffer wheel, the buffer wheel is rotatably arranged on the movable rod, a spring is sleeved on the outside of the guide rod, and the spring is fixed between the mounting groove and the movable rod.

Description

Technical Field

[0001] The present invention relates to the technical field of steam turbines, and in particular to a monitoring module and a monitoring method for the axial thrust of a steam turbine. Background Art

[0002] Thrust pads, also known as thrust bearings, are used to determine the axial position of the rotor within the cylinder. Over the course of a steam turbine's service life, changes in axial thrust can cause the pads to overheat, affecting normal operation.

[0003] According to the "Steam Turbine Thrust Pad Axial Thrust Measurement Device" (publication number CN206190737U), a force-sensing element is installed inside the thrust pad and connected to external equipment to monitor the axial thrust acting on the thrust pad in real time. However, due to the high power of steam turbines, the force-sensing element is subjected to long-term axial thrust, which can cause increasing damage to the internal sensitive element. Furthermore, the device lacks a buffer component to protect the force-sensing element without interfering with accurate axial thrust monitoring data. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention provides a monitoring module and monitoring method for the axial thrust of a steam turbine. The element buffer assembly buffers the force-measuring sensitive element to prevent it from being damaged. In combination with the set elastic force measuring element, a comprehensive calculation is performed on the axial thrust measured after buffering without interfering with the correct axial thrust monitoring data.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a monitoring module for the axial thrust of a steam turbine, comprising a shoe seat, wherein a plurality of thrust shoes are evenly installed in the shoe seat along the circumferential direction with the center point as the center of the circle, an outer circular groove is provided on the outer surface of the thrust shoe, an inner circular groove is connected to the lower middle portion of the outer circular groove and is concentric with the outer circular groove, a force-measuring sensitive element is provided in the outer circular groove, and a plurality of groups of element buffer assemblies for buffering the force-measuring sensitive elements are evenly distributed on the inner ring surface of the inner circular groove, and the element buffer assembly includes a plurality of elements evenly provided on the inner ring surface of the inner circular groove along the circumferential direction. An accommodating groove; a buffer wheel movably arranged in the accommodating groove, the arc surface of the buffer wheel rollingly contacting with the outer wall of the force-measuring sensitive element; mounting grooves symmetrically distributed on both sides of the accommodating groove, the mounting grooves being opened in the thrust shoe and mutually interpenetrating with the accommodating groove; a guide rod passing through the mounting groove, one end of the guide rod being fixed on the groove wall of the mounting groove, and the other end passing through the interior of one end of a movable rod, the movable rod passing through the interior of the buffer wheel, the buffer wheel being rotatably arranged on the movable rod; a spring sleeved on the outside of the guide rod, the spring being fixedly connected between the groove wall of the mounting groove and the outer surface of the movable rod, and an elastic force measuring element being provided on one side of the spring.

[0006] As a preferred technical solution of the present invention, a limiting plate is fixedly provided on the end of the guide rod away from the spring, and the diameter of the limiting plate is larger than the diameter of the guide rod.

[0007] As a preferred technical solution of the present invention, the inner part of the outer circular groove is movably equipped with an adjustment block that is adapted to its shape and size. The adjustment block includes a disc body, and a U-shaped groove is provided on the outer surface of the disc body on the side in contact with the outer circular groove. The U-shaped groove fits with the inner circular groove. The force sensitive element is placed in the space formed by the U-shaped groove and the inner circular groove. A spherical support is fixed on the outer surface of the adjustment block away from the U-shaped groove.

[0008] As a preferred technical solution of the present invention, a strip-shaped wire outlet groove is opened on one side of the inner circular groove. The wire outlet groove is distributed in the same direction as the U-shaped groove and is arranged in the radial surface direction of the thrust washer.

[0009] As a preferred technical solution of the present invention, the outer surface of the buffer wheel in contact with the force-measuring sensitive element is provided with obliquely distributed anti-slip grooves.

[0010] As a preferred technical solution of the present invention, a wiring hole is opened through the radial surface of the thrust washer, the wiring hole is connected to the wire outlet groove, a wiring groove is opened on the surface of the washer seat corresponding to the wiring hole, and one end of the wiring hole is located in the wiring groove.

[0011] As a preferred technical solution of the present invention, the upper part of the thrust washer is tightly attached to the bottom of the wire pressing plate, a wiring groove is opened inside the washer seat, the wiring groove is connected to the wiring groove, and a wire pressing plate is also provided above it. The data cable of the force measuring sensitive element passes through the wire outlet groove and the wiring hole, is wound from the wiring groove to the wiring groove, and is pressed by the wire pressing plate.

[0012] The present invention also provides a method for monitoring the axial thrust of a steam turbine, the monitoring method comprising the following steps:

[0013] S1. A dynamometer is composed of a thrust plate, a force sensing element, and an external dynamic signal data acquisition and transmission device. The dynamometer is placed at one end of the turbine's speed governor and one end of the generator, and at least four dynamometers are placed.

[0014] S2. Connect the dynamometer to a device equipped with modal analysis software;

[0015] S3. After the turbine is started, when the dynamometer is subjected to axial thrust, the internal strain gauge changes, causing the resistance value in the bridge circuit to change, and resistance compensation is performed through the junction box. The signal is input into the thrust display instrument for measurement and display.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] When the force-measuring sensitive element is subjected to axial thrust, it is squeezed and tends to move downward, causing the force-measuring sensitive element to drive the buffer wheel to roll. Sometimes the force-measuring sensitive element will also deviate, squeezing the buffer wheel, causing the buffer wheel to move into the accommodating groove, and driving the movable rod to move into the accommodating groove, causing the movable rod to slide on the guide rod, compressing the spring sleeved on the guide rod. The spring buffers the force-measuring sensitive element to prevent it from being damaged. Combined with the elastic force measuring element, it performs a comprehensive calculation with the axial thrust measured after buffering, and will not interfere with the correct axial thrust monitoring data. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the appearance of the present invention.

[0019] Figure 2 This is a schematic diagram of the thrust pad structure of the present invention.

[0020] Figure 3 This is a structural schematic diagram of the force-measuring sensitive element of the present invention.

[0021] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle.

[0022] Figure 5 This is a top view of the component buffer assembly described in the present invention.

[0023] Figure 6 This is an enlarged view of the component buffer assembly described in the present invention.

[0024] Figure 7 This is a structural diagram of the adjustment block of the present invention.

[0025] The names corresponding to the reference numerals are:

[0026] 1. Wafer seat; 2. Thrust plate; 3. Thrust washer; 301. Outer circular groove; 302. Inner circular groove; 303. Wire outlet groove; 4. Adjustment block; 5. Wire routing groove; 6. Wire pressing plate; 7. Buffer wheel; 8. Force sensitive element; 9. Accommodating groove; 10. Mounting groove; 11. Spring; 12. Guide rod; 13. Movable rod; 14. U-shaped groove; 15. Spherical support. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings and examples. The embodiments of the present invention include but are not limited to the following examples.

[0028] Example 1

[0029] Please refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 As shown, the present invention provides a monitoring module and monitoring method for the axial thrust of a steam turbine, including a shoe seat 1, wherein a plurality of thrust shoes 3 are evenly installed in the shoe seat 1 along the circumferential direction with the center point as the center of the circle, an outer circular groove 301 is provided on the outer surface of the thrust shoe 3, and an inner circular groove 302 concentric with the outer circular groove 301 is connected and provided below the middle of the outer circular groove 301, a force-measuring sensitive element 8 is provided in the outer circular groove 301, and a plurality of groups of element buffer assemblies for buffering the force-measuring sensitive element 8 are evenly distributed on the inner ring surface of the inner circular groove 302, and the element buffer assembly includes a plurality of accommodating grooves 9 evenly provided on the inner ring surface of the inner circular groove 302 along the circumferential direction, and movable grooves 9 are provided in the accommodating grooves 9. A buffer wheel 7 is provided, the arc surface of the buffer wheel 7 is in rolling contact with the outer wall of the force-measuring sensitive element 8, and mounting grooves 10 are symmetrically distributed on both sides of the accommodating groove 9. The mounting groove 10 is opened in the thrust shoe 3 and is interconnected with the accommodating groove 9. A guide rod 12 is passed through the mounting groove 10, one end of the guide rod 12 is fixed to the groove wall of the mounting groove 10, and the other end is passed through the interior of one end of a movable rod 13, the movable rod 13 is passed through the interior of the buffer wheel 7, and the buffer wheel 7 is rotatably provided on the movable rod 13. A spring 11 is provided on the outside of the guide rod 12, and the spring 11 is fixedly connected between the groove wall of the mounting groove 10 and the outer surface of the movable rod 13. An elastic force measuring element is provided on one side of the spring 11;

[0030] In a specific embodiment of the present invention, when the force-measuring sensitive element 8 is subjected to an axial thrust, it is squeezed and has a tendency to move downward, so that the force-measuring sensitive element 8 drives the buffer wheel 7 to roll. Sometimes the force-measuring sensitive element 8 will also deviate, squeezing the buffer wheel 7, so that the buffer wheel 7 moves into the receiving groove 9, and drives the movable rod 13 to move into the receiving groove 9, so that the movable rod 13 slides on the guide rod 12, compressing the spring 11 sleeved on the guide rod 12. After the spring 11 is deformed by the force, it has elastic potential energy that can be restored to its original shape, and then the spring 11 has a rebound movement tendency. , and under the action of elastic potential energy, a movement trend is generated to drive the buffer wheel 7 to move outward through the movable rod 13, which buffers the force-measuring sensitive element 8 to prevent it from being damaged. In actual use, the elastic force of the spring 11 will affect the measurement of the axial thrust. Then, an element for measuring the elastic force of the spring 11 should be set at the position of the distribution spring 11, and connected to a device equipped with modal analysis software. The measured data after buffering are compared, and two dynamic curves are simulated, one for the axial thrust and the other for the spring 11. Finally, the correct axial thrust is calculated and displayed according to the corresponding calculation formula.

[0031] Example 2

[0032] This embodiment is an improvement on the first embodiment. For details, please refer to Figure 6 A limit plate is fixed on one end of the guide rod 12 away from the spring 11, and the diameter of the limit plate is larger than the diameter of the guide rod 12;

[0033] In this embodiment: when the force-measuring sensitive element 8 is subjected to axial thrust, it is squeezed and then drives the buffer wheel 7 to roll, and sometimes squeezes the buffer wheel 7, so that the buffer wheel 7 drives the movable rod 13 to move into the accommodating groove 9, so that the movable rod 13 moves on the guide rod 12 and compresses the spring 11. The limit plate set on the guide rod 12 can prevent the movable rod 13 from detaching from the guide rod 12.

[0034] Example 3

[0035] This embodiment is an improvement on the first embodiment. For details, please refer to Figure 1 、 Figure 2 、 Figure 7 The outer circular groove 301 is internally movable and equipped with an adjustment block 4 that is adapted to its shape and size. The adjustment block 4 includes a disc body, and a U-shaped groove 14 is provided on the outer surface of the side in contact with the outer circular groove 301. The U-shaped groove 14 fits in with the inner circular groove 302. The force sensitive element 8 is placed in the space formed by the U-shaped groove 14 and the inner circular groove 302. A spherical support 15 is fixed on the outer surface of the adjustment block 4 away from the U-shaped groove 14. A strip-shaped outlet groove 303 is provided on one side of the inner circular groove 302. The outlet groove 303 is distributed in the same direction as the U-shaped groove 14. It is arranged in the radial surface direction of the thrust washer 3, and a wiring hole is opened on the radial surface of the thrust washer 3, and the wiring hole is communicated with the wire outlet groove 303. A wiring groove is opened on the surface of the tile seat 1 corresponding to the wiring hole, and one end of the wiring hole is located in the wiring groove. The upper part of the thrust washer 3 is tightly attached to the bottom of the wire pressing plate 6. A wiring groove 5 is opened inside the tile seat 1, and the wiring groove 5 is connected to the wiring groove. A wire pressing plate 6 is also provided above it. The data line of the force sensitive element 8 passes through the wire outlet groove 303 and the wiring hole, is wound from the wiring groove to the wiring groove 5, and is pressed by the wire pressing plate 6;

[0036] In this embodiment: when using the device, the force-measuring sensitive element 8 is placed in the inner circular groove 302, and then transferred into the outer circular groove 301 to the adjustment block 4. The U-shaped groove 14 on the adjustment block 4 faces the force-measuring sensitive element 8. Even if the force-measuring sensitive element 8 is placed in the space formed by the U-shaped groove 14 and the inner circular groove 302, the data line of the force-measuring sensitive element 8 passes through the outlet groove 303 and the wiring hole on the thrust washer 3 in sequence, and then is wound from the wiring groove on the thrust washer 3 to the wiring groove 5 opened inside the tile seat 1, and is pressed by the wire pressing plate 6 above the wiring groove 5. The thrust plate 2, the force-measuring sensitive element 8 and the external dynamic signal data acquisition and transmission equipment constitute a dynamometer. The dynamometer is placed at one end of the speed governor and one end of the generator of the steam turbine, and more than 4 units are placed. Then the dynamometer and the equipment installed with modal analysis software are connected to start monitoring the axial thrust.

[0037] Example 4

[0038] This embodiment is an improvement on the first embodiment. For details, please refer to Figure 3 , the outer surface of the buffer wheel 7 in contact with the force sensing element 8 is provided with obliquely distributed anti-slip grooves;

[0039] In this embodiment: when the force-measuring sensitive element 8 is subjected to axial thrust, it is squeezed and then drives the buffer wheel 7 to roll. The anti-slip grooves provided on the outer surface of the buffer wheel 7 can increase the friction between it and the force-measuring sensitive element 8, thereby preventing the force-measuring sensitive element 8 and the buffer wheel 7 from separating.

[0040] Example 5

[0041] A method for monitoring the axial thrust of a steam turbine, comprising the following steps:

[0042] S1, a dynamometer is composed of a thrust plate 2, a force sensing element 8 and an external dynamic signal data acquisition and transmission device. The dynamometer is placed at one end of the turbine governor and one end of the generator, and more than four dynamometers are placed;

[0043] S2. Connect the dynamometer to a device equipped with modal analysis software;

[0044] S3. After the turbine is started, when the dynamometer is subjected to axial thrust, the internal strain gauge changes, causing the resistance value in the bridge circuit to change. The resistance is compensated through the junction box, and the signal is input to the thrust display instrument for measurement and display.

[0045] In this embodiment, a dynamometer consisting of a thrust plate 2, a force-sensing element 8, and external dynamic signal data acquisition and transmission equipment is placed at one end of the turbine's speed governor and one end of the generator. At least four dynamometers are placed. The dynamometers are connected to equipment equipped with modal analysis software. After the turbine is started, when the dynamometer is subjected to axial thrust, the internal strain gauge changes, causing the resistance value in the bridge circuit to change. Resistance compensation is performed through the junction box, and the signal is input into the thrust display instrument for measurement and display. The monitoring module can promptly monitor the thrust changes and transmit and display them.

[0046] Working principle: Place the dynamometer consisting of the thrust plate 2, the force sensitive element 8 and the external dynamic signal data acquisition and transmission equipment at one end of the turbine governor and one end of the generator, and place more than 4 dynamometers, connect the dynamometer to the equipment installed with the modal analysis software, after the turbine is started, when the force sensitive element 8 is subjected to axial thrust, it is squeezed and has a tendency to move downward, so that the force sensitive element 8 drives the buffer wheel 7 to roll, and sometimes the force sensitive element 8 will also produce cheapness, squeezing the buffer wheel 7, so that the buffer wheel 7 moves into the receiving groove 9, and drives the movable rod 13 to move into the receiving groove 9, so that the movable rod 13 slides on the guide rod 12, compressing the spring 11 mounted on the guide rod 12. After the spring 11 is deformed by the force, it has elastic potential energy that can be restored to its original shape, and then the spring 1 1 has a tendency to rebound, and under the action of elastic potential energy, it generates a tendency to move the buffer wheel 7 outward through the movable rod 13, which buffers the force-measuring sensitive element 8 to prevent it from being damaged. In actual use, the elastic force of the spring 11 will affect the measurement of the axial thrust. Then, an element for measuring the elastic force of the spring 11 should be set at the position of the distribution spring 11 and connected to a device equipped with modal analysis software. When the dynamometer is subjected to thrust, the internal strain gauge changes, causing the resistance value in the bridge circuit to change, and resistance compensation is performed through the junction box. The signal is input into the thrust display instrument for measurement and display. By comparing the measured data after buffering, two dynamic curves are simulated, one for axial thrust and the other for spring 11 elastic force. Finally, the correct axial thrust is calculated and displayed according to the corresponding calculation formula.

[0047] The above embodiments are only preferred implementation methods of the present invention. Any changes or modifications that are made to the main design concept and spirit of the present invention and have no substantive significance, as long as the technical problems they solve are still consistent with the present invention, should be included in the scope of protection of the present invention.

Claims

1. A monitoring module for the axial thrust of a steam turbine, comprising a shoe seat (1), wherein a plurality of thrust shoes (3) are evenly installed in the shoe seat (1) along the circumferential direction with a center point as the center of the circle, an outer circular groove (301) is provided on the outer surface of the thrust shoe (3), an inner circular groove (302) concentric with the outer circular groove (301) is provided below the middle of the outer circular groove (301), a force sensing element (8) is provided in the outer circular groove (301), and the invention is characterized in that: Multiple groups of element buffering assemblies for buffering the force-measuring sensitive element (8) are evenly distributed on the inner ring surface of the inner circular groove (302), and the element buffering assemblies include: A plurality of receiving grooves (9) are evenly arranged on the inner surface of the inner circular groove (302) along the circumferential direction; a buffer wheel (7) movably arranged in the accommodating groove (9), wherein the arc surface of the buffer wheel (7) is in rolling contact with the outer wall of the force-measuring sensitive element (8); Mounting grooves (10) symmetrically distributed on both sides of the receiving groove (9), the mounting grooves (10) being opened in the thrust washer (3) and interpenetrating with the receiving groove (9); A guide rod (12) is provided in the installation groove (10), one end of the guide rod (12) is fixed to the groove wall of the installation groove (10), and the other end is provided inside one end of a movable rod (13), the movable rod (13) is provided inside the buffer wheel (7), and the buffer wheel (7) is rotatably provided on the movable rod (13); A spring (11) is sleeved on the outside of the guide rod (12), the spring (11) is fixedly connected between the groove wall of the installation groove (10) and the outer surface of the movable rod (13), and an elastic force measuring element is provided on one side of the spring (11).

2. A steam turbine axial thrust monitoring module according to claim 1, characterized in that: A limiting plate is fixedly provided on one end of the guide rod (12) away from the spring (11), and the diameter of the limiting plate is larger than the diameter of the guide rod (12).

3. The monitoring module for the axial thrust of a steam turbine according to claim 1, characterized in that: An adjustment block (4) having a shape and size adapted to the outer circular groove (301) is movably assembled inside the outer circular groove (301). The adjustment block (4) comprises a disc body, and a U-shaped groove (14) is provided on the outer surface of the side in contact with the outer circular groove (301). The U-shaped groove (14) is fitted with the inner circular groove (302). The force sensing element (8) is placed in a space formed by the U-shaped groove (14) and the inner circular groove (302). A spherical support (15) is fixedly provided on the outer surface of the adjustment block (4) away from the U-shaped groove (14).

4. The monitoring module for the axial thrust of a steam turbine according to claim 3, characterized in that: A strip-shaped wire outlet groove (303) is provided on one side of the inner circular groove (302). The wire outlet groove (303) is distributed in the same direction as the U-shaped groove (14) and is arranged in the radial surface direction of the thrust washer (3).

5. The steam turbine axial thrust monitoring module according to claim 1, characterized in that: The outer surface of the buffer wheel (7) in contact with the force-measuring sensitive element (8) is provided with anti-skid patterns distributed obliquely.

6. The steam turbine axial thrust monitoring module according to claim 4, characterized in that: A wiring hole is provided on the radial surface of the thrust washer (3), the wiring hole being in communication with the outlet groove (303), a wiring groove is provided on the surface of the washer seat (1) at a position corresponding to the wiring hole, and one end of the wiring hole is located in the wiring groove.

7. The steam turbine axial thrust monitoring module according to claim 6, characterized in that: The upper part of the thrust shoe (3) is closely attached to the lower part of the wire pressing plate (6); a wiring groove (5) is provided inside the shoe seat (1); the wiring groove (5) is connected to the wiring groove; a wire pressing plate (6) is further provided above the wiring groove; the data line of the force sensing element (8) passes through the outlet groove (303) and the wiring hole, is wound from the wiring groove to the wiring groove (5), and is pressed by the wire pressing plate (6).

8. A method for monitoring the axial thrust of a steam turbine, characterized in that: The monitoring module for the axial thrust of a steam turbine according to any one of claims 1 to 7, wherein the monitoring method comprises the following steps: S1, a dynamometer is composed of a thrust plate (2), a force sensing element (8) and an external dynamic signal data acquisition and transmission device. The dynamometer is placed at one end of the turbine governor and one end of the generator, and more than four dynamometers are placed; S2. Connect the dynamometer to a device equipped with modal analysis software; S3. After the turbine is started, when the dynamometer is subjected to axial thrust, the internal strain gauge changes, causing the resistance value in the bridge circuit to change, and resistance compensation is performed through the junction box. The signal is input into the thrust display instrument for measurement and display.

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