A thrust bearing for steam turbines

Abstract

This application provides a thrust bearing for a steam turbine, including a bearing housing, a bearing body and a steam turbine rotor disposed within the bearing housing, a thrust disk disposed on the steam turbine rotor, and thrust bearings mirror-arranged on both sides of the thrust disk and the bearing housing. The thrust bearings include: The axial thrust generated during the operation of the steam turbine is transmitted to the thrust bearings through the thrust disk, and sequentially to the bearing pad mounting rings. The mounting ring bosses on the bearing pad mounting rings are tightly fitted with the bearing body, and a certain elastic deformation occurs in the grooves located between the mounting ring bosses. The strain gauges in the strain detector detect this deformation, and the stress detection system processes the signals detected by the strain detectors to obtain the axial thrust and displays the thrust value in real time. This enables real-time measurement and monitoring of the axial thrust during steam turbine operation, ensuring the safe operation of the steam turbine under various operating conditions.

Description

Technical Field

[0001] This application belongs to the field of steam turbine technology, specifically relating to a thrust bearing for steam turbines. Background Technology

[0002] As a key power unit in thermal power plants, the steam turbine operates by converting high-temperature, high-pressure steam into electrical energy through a process where high-temperature, high-pressure steam is depressurized and accelerated by nozzles and diaphragms, driving the rotor to rotate at high speed. This, in turn, drives the generator to perform work. During this process, the high-temperature, high-pressure steam flows axially along the turbine, subjecting the rotor to a certain axial thrust. To balance this thrust, in addition to using high-pressure and intermediate-pressure cylinders with counter-current arrangement and balancing drums, the turbine design also requires a thrust bearing. The thrust bearing has two main functions: first, it serves as a relative dead point to ensure the axial position of the turbine rotor and stationary components remains fixed; second, it withstands the axial thrust generated during rotor operation to ensure the safe and stable operation of the turbine under various load conditions. Because excessive axial thrust during turbine operation can cause the thrust bearing to overheat, and even lead to bearing bushing corrosion, resulting in rubbing between the rotor and stationary components and causing serious damage to the turbine, monitoring the thrust bearing is crucial.

[0003] Currently, existing steam turbines mainly rely on monitoring the tungsten gold temperature of the thrust bearing pads to determine whether the thrust bearing is within its acceptable range. To ensure safe operation of the unit, the monitoring system will issue an alarm and shutdown signal when the pad temperature exceeds a set value; however, this method cannot measure and determine the true thrust value during rotor operation, posing a potential risk to the safe operation of the unit. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related technologies.

[0005] To address the aforementioned problems, this application provides a thrust bearing for a steam turbine, comprising a bearing housing, a bearing body and a steam turbine rotor disposed within the bearing housing, a thrust disk disposed on the steam turbine rotor, and a positive thrust bearing and a negative thrust bearing respectively disposed between the two sides of the thrust disk and the bearing housing, wherein both the positive thrust bearing and the negative thrust bearing are sleeved within the bearing housing, and the positive thrust bearing and the negative thrust bearing have identical structures. The positive thrust bearing includes:

[0006] The bearing mounting ring has mounting ring bosses spaced apart on the side facing the bearing seat, and grooves are formed between the mounting ring bosses, with strain detectors installed in the grooves;

[0007] The thrust pad is disposed on the side of the pad mounting ring away from the mounting ring boss, and the thrust pad is located between the pad mounting ring and the thrust disc;

[0008] A stress measurement system, connected to the strain detector, is used to convert the deformation of the strain detector into a thrust value.

[0009] Optionally, a first reinforcing rib and a second reinforcing rib are provided in the groove and along its radial direction, and the strain detector is located between the first reinforcing rib and the second reinforcing rib.

[0010] Optionally, the first reinforcing rib and the second reinforcing rib have the same height, and the height of both the first reinforcing rib and the second reinforcing rib is less than the height of the mounting ring boss.

[0011] Optionally, the height of both the first reinforcing rib and the second reinforcing rib is 3mm-5mm less than the height of the mounting ring boss.

[0012] Optionally, the number of thrust pads is multiple, and the thrust pads are detachably disposed on the side of the pad mounting ring away from the mounting ring boss.

[0013] Optionally, it also includes a mounting pin. The mounting ring of the tile has an inner mounting hole and an outer mounting hole on the side away from the mounting ring boss. The thrust tile has an inner mounting hole and an outer mounting hole. A mounting pin is provided between the inner mounting hole of the mounting ring and the inner mounting hole of the tile, and between the outer mounting hole of the mounting ring and the outer mounting hole of the tile.

[0014] Optionally, the thrust pad is provided with a pad support block on the side facing the pad mounting ring.

[0015] Optionally, the strain detector is a resistance strain gauge.

[0016] Optionally, the tile mounting ring, the mounting ring boss, the first reinforcing rib, and the second reinforcing rib are integrally formed.

[0017] Optionally, the positive thrust bearing and the negative thrust bearing are also equipped with resistance temperature detectors.

[0018] Beneficial effects

[0019] The thrust bearing for a steam turbine provided in the embodiments of this utility model has the following beneficial effects: by providing mounting ring bosses at intervals on the side of the bearing housing facing the bearing pad mounting ring, and installing strain detectors in the grooves between the mounting ring bosses, the axial thrust generated during the operation of the steam turbine is supplied to the thrust bearing through the thrust disc, and will be supplied to the bearing pad mounting rings in sequence. The mounting ring bosses on the bearing pad mounting rings will fit tightly against the bearing housing, and a certain elastic deformation will be generated in the grooves between the mounting ring bosses. The strain gauges in the strain detectors detect this deformation, and the stress detection system will process the signals detected by the strain detectors to obtain the axial thrust and display the thrust value in real time. This can realize the real-time measurement and monitoring of the axial thrust during the operation of the steam turbine, ensuring the safe operation of the steam turbine under various operating conditions. Attached Figure Description

[0020] Figure 1 This is a structural diagram of the thrust bearing of this utility model;

[0021] Figure 2 This is a structural diagram of the tile mounting ring of this utility model;

[0022] Figure 3 This is a structural diagram of the thrust bearing of this utility model;

[0023] Figure 4 This is a cross-sectional view of the bearing housing of this utility model.

[0024] The reference numerals in the attached figures are as follows:

[0025] 1. Bearing housing; 2. Bearing body; 3. Steam turbine rotor; 4. Thrust disc; 5. Positive thrust bearing; 6. Negative thrust bearing; 7. Bearing pad mounting ring; 8. Mounting ring boss; 9. Groove; 10. Strain gauge; 11. Thrust pad; 12. First reinforcing rib; 13. Second reinforcing rib; 14. Mounting pin; 15. Inner mounting hole of mounting ring; 16. Outer mounting hole of mounting ring; 17. Inner mounting hole of bearing pad; 18. Outer mounting hole of bearing pad; 19. Bearing pad support block; 20. Resistance temperature detector. Detailed Implementation

[0026] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0030] See also Figures 1-4 As shown, an embodiment of this application provides a thrust bearing for a steam turbine, including a bearing housing 1. A bearing body 2 and a steam turbine rotor 3 are disposed within the bearing housing 1. A thrust disk 4 is disposed on the steam turbine rotor 3. A positive thrust bearing 5 and a negative thrust bearing 6 are respectively disposed between the two sides of the thrust disk 4 and the bearing housing 1. Both the positive thrust bearing 5 and the negative thrust bearing 6 are sleeved within the bearing housing 1. The positive thrust bearing 5 and the negative thrust bearing 6 have the same structure. The positive thrust bearing 5 includes:

[0031] The tile mounting ring 7 has mounting ring bosses 8 spaced apart on the side facing the bearing seat 1, and grooves 9 are formed between the mounting ring bosses 8. Strain detectors 10 are installed in the grooves 9.

[0032] Thrust pad 11, the thrust pad 11 is disposed on the side of the pad mounting ring 7 away from the mounting ring boss 8, and the thrust pad 11 is located between the pad mounting ring 7 and the thrust plate 4;

[0033] A stress measurement system, which is connected to the strain detector 10, is used to convert the deformation of the strain detector 10 into a thrust value.

[0034] Specifically, bearing housing 1 provides a mounting base for bearing body 2, turbine rotor 3, thrust disk 4, positive thrust bearing 5, and negative thrust bearing 6. Positive thrust bearing 5 and negative thrust bearing 6 are respectively installed between thrust disk 4 and bearing housing 1, and positive thrust bearing 5 and negative thrust bearing 6 have the same structure. During the rotation of turbine rotor 3, it generates axial thrust, which is transmitted to positive thrust bearing 5 or negative thrust bearing 6 through thrust disk 4, generating thrust on positive thrust bearing 5 or negative thrust bearing 6. The thrust is transmitted to pad mounting ring 7 through thrust pad 11. At this time, the mounting ring boss 8 on pad mounting ring 7 will fit tightly with bearing body 2, causing a certain elastic deformation in the groove 9 between mounting ring bosses 8. The strain gauge detector in strain detector 10 detects this deformation. The signal detected by strain detector 10 is transmitted to stress detection system through wires. Stress measurement system consists of signal conditioning module, A / D converter and data processing unit. The signal conditioning module amplifies and filters the signal from the strain detector 10 to eliminate noise interference; the A / D converter converts the analog signal into a digital signal; the data processing unit converts the strain value into the corresponding axial thrust through the built-in calibration algorithm and displays the thrust value in real time, which can realize the real-time measurement and monitoring of thrust during turbine operation.

[0035] Among them, there are multiple strain detectors 10, which are installed at intervals in the grooves 9 between the mounting ring bosses 8. They can detect the thrust value at different positions of the thrust bearing, which makes it convenient for staff to analyze the thrust value at different positions. They can also calculate the average axial thrust value of the entire thrust bearing based on the thrust value at each point.

[0036] The stress detection system also has an over-limit alarm function. When the axial thrust exceeds the preset threshold, it will issue an audible and visual alarm to remind the operator and prevent abnormal operating conditions during turbine operation from causing turbine damage.

[0037] Among them, the strain detectors 10 can be arranged in an array. By processing the data detected by multiple strain detectors 10, the average value can be obtained, which can eliminate the random error of single-point measurement and improve the accuracy of axial thrust measurement.

[0038] See also Figures 1-3 As shown, a first reinforcing rib 12 and a second reinforcing rib 13 are provided in the groove 9 and along its radial direction, and the strain detector 10 is located between the first reinforcing rib 12 and the second reinforcing rib 13.

[0039] Specifically, a first reinforcing rib 12 and a second reinforcing rib 13 are installed within the groove 9. These ribs are spaced apart along the radial direction of the tile mounting ring 7. The strain detector 10 is located between these two ribs, with the first reinforcing rib 12 closer to the inner side of the groove 9 and the second reinforcing rib 13 closer to the outer side, forming bidirectional support for the bottom of the groove 9. When the axial thrust is unevenly distributed radially, the first reinforcing ribs 12 and 13 balance the load difference through their own deformation, ensuring that the strain detector 10 is always in a uniformly stressed area, guaranteeing the consistency of the measurement data. By incorporating the first reinforcing ribs 12 and 13, both structural strength and measurement accuracy are improved without affecting the original function of the tile mounting ring 7.

[0040] See also Figures 1-3 As shown, the first reinforcing rib 12 and the second reinforcing rib 13 have the same height, and the height of both the first reinforcing rib 12 and the second reinforcing rib 13 is less than the height of the mounting ring boss 8.

[0041] The height of the first reinforcing rib 12 and the second reinforcing rib 13 is 3mm-5mm less than the height of the mounting ring boss 8.

[0042] Specifically, when the thrust plate 4 applies axial thrust to the positive thrust bearing 5 or the negative thrust bearing 6, the axial thrust is transmitted to the bearing mounting ring 7 through the thrust pad 11, causing the mounting ring boss 8 to contact the bearing body 2. Furthermore, by setting the height of the first reinforcing rib 12 and the second reinforcing rib 13 to be less than the height of the mounting ring boss 8, the first reinforcing rib 12 and the second reinforcing rib 13 do not contact the bearing body 2 when the mounting ring boss 8 contacts it. This achieves elastic deformation at the groove 9, providing space for axial thrust measurement. Simultaneously, when the axial thrust is overloaded, the first reinforcing rib 12 and the second reinforcing rib 13 can provide secondary support to the bearing mounting ring 7, preventing excessive deformation of the groove 9 due to axial thrust overload, which could damage the strain detector 10.

[0043] See also Figures 1-3 As shown, there are multiple thrust pads 11, and each thrust pad 11 is detachably mounted on the side of the pad mounting ring 7 away from the mounting ring boss 8.

[0044] It also includes a mounting pin 14. The tile mounting ring 7 has an inner mounting hole 15 and an outer mounting hole 16 on the side away from the mounting ring boss 8. The thrust tile 11 has an inner mounting hole 17 and an outer mounting hole 18. The mounting pin 14 is provided between the inner mounting hole 15 and the inner mounting hole 17 and between the outer mounting hole 16 and the outer mounting hole 18.

[0045] Specifically, the number of thrust bearings 11 is set to multiple, evenly distributed along the circumference of the bearing mounting ring 7, with gaps maintained between adjacent thrust bearings 11. This distribution allows the axial thrust to be evenly distributed to each thrust bearing 11, reducing the load borne by a single bearing and effectively preventing wear or melting caused by local overload. At the same time, the existence of gaps provides space for the thermal expansion of the thrust bearings 11, preventing deformation caused by expansion and compression between the thrust bearings 11 when the turbine operating temperature rises, and ensuring that the formation of the oil film is not disturbed.

[0046] The thrust bearing 11 is detachably mounted on the bearing mounting ring 7, and the two are positioned and securely connected by a mounting pin 14. The bearing mounting ring 7 has an inner mounting hole 15 and an outer mounting hole 16 on the side away from the mounting ring boss 8. Correspondingly, the thrust bearing 11 has an inner mounting hole 17 and an outer mounting hole 18. The inner mounting hole 15 corresponds to the inner mounting hole 17, and the outer mounting hole 16 corresponds to the outer mounting hole 18. The mounting pin 14 is installed between the inner mounting hole 15 and the inner mounting hole 17, and between the outer mounting hole 16 and the outer mounting hole 18, thus achieving a secure connection between the thrust bearing 11 and the bearing mounting ring 7. The detachable design facilitates maintenance and replacement of the thrust bearing 11. When a thrust bearing 11 experiences wear, burning, or other malfunctions, it is not necessary to completely disassemble the bearing mounting ring 7; only the damaged thrust bearing 11 needs to be replaced, saving replacement costs and improving maintenance efficiency.

[0047] See also Figures 1-3 As shown, a tile support block 19 is provided on the side of the thrust tile facing the tile mounting ring.

[0048] Specifically, the tile support block 19, which is provided on the side of the thrust tile 11 facing the tile mounting ring 7, can transmit the thrust received by the thrust tile 11 to the tile mounting ring 7, and the plane of the tile support block 19 is in full contact with the tile mounting ring 7.

[0049] See also Figure 1 As shown, the strain detector 10 is a resistance strain gauge.

[0050] Specifically, the strain detector 10 uses a resistance strain gauge, which can fit tightly against the arc-shaped surface at the bottom of the groove 9 after installation. It has the characteristics of high sensitivity and small size, making it convenient to install and use. When the axial thrust is transmitted to the pad mounting ring 7 through the thrust pad 11, the groove 9 part of the pad mounting ring 7 undergoes a slight deformation under the action of the axial thrust, and its resistance value changes accordingly. The signal is transmitted to the stress measurement system through the wire to achieve stable and rapid measurement.

[0051] See also Figure 1As shown, the tile mounting ring 7, the mounting ring boss 8, the first reinforcing rib 12, and the second reinforcing rib 13 are integrally formed.

[0052] Specifically, the tile mounting ring 7, mounting ring boss 8, first reinforcing rib 12, and second reinforcing rib 13 are integrally formed into a structure. The seamless connection of each component is achieved through forging process, eliminating stress concentration points that may exist in traditional splicing structures and improving the overall load-bearing capacity and fatigue life of the structure.

[0053] See also Figure 1 As shown, a resistance temperature detector 20 is also provided on the thrust bearing 5.

[0054] Specifically, the resistance thermometer installed on the thrust bearing of the steam turbine can monitor the temperature near the ebony layer of the thrust bearing 11, and is a temperature measuring element that ensures the safe operation of the thrust bearing 11. It can capture the temperature changes of the ebony layer in real time, provide operators with accurate temperature data, and promptly warn of potential overheating risks. In conjunction with thrust measurement, it ensures that the axial thrust is within the range that the thrust bearing can withstand, thus guaranteeing the safe and stable operation of the steam turbine.

[0055] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A thrust bearing for a steam turbine, comprising a bearing housing (1), wherein a bearing body (2) and a steam turbine rotor (3) are disposed within the bearing housing (1), a thrust disk (4) is disposed on the steam turbine rotor (3), a positive thrust bearing (5) and a negative thrust bearing (6) are respectively disposed between the two sides of the thrust disk (4) and the bearing housing (1), the positive thrust bearing (5) and the negative thrust bearing (6) are both sleeved within the bearing housing (1), and the positive thrust bearing (5) and the negative thrust bearing (6) have the same structure, characterized in that, The thrust bearing (5) includes: The tile mounting ring (7) has mounting ring bosses (8) spaced apart on the side facing the bearing seat (1), and grooves (9) are opened between the mounting ring bosses (8), and strain detectors (10) are installed in the grooves (9); Thrust pad (11), the thrust pad (11) is disposed on the side of the pad mounting ring (7) away from the mounting ring boss (8), the thrust pad (11) is located between the pad mounting ring (7) and the thrust plate (4); A stress measurement system, which is connected to the strain detector (10), is used to convert the deformation of the strain detector (10) into a thrust value.

2. The thrust bearing for a steam turbine according to claim 1, characterized by The groove (9) is provided with a first reinforcing rib (12) and a second reinforcing rib (13) in its radial direction, and the strain detector (10) is located between the first reinforcing rib (12) and the second reinforcing rib (13).

3. The thrust bearing for a steam turbine according to claim 2, characterized by The first reinforcing rib (12) and the second reinforcing rib (13) have the same height, and the height of the first reinforcing rib (12) and the second reinforcing rib (13) is less than the height of the mounting ring boss (8).

4. The thrust bearing for a steam turbine according to claim 3, characterized by The heights of the first reinforcing rib (12) and the second reinforcing rib (13) are both 3mm-5mm less than the height of the mounting ring boss (8).

5. The thrust bearing for a steam turbine as set forth in claim 1, characterized by The number of thrust pads (11) is multiple, and the thrust pads (11) are detachably disposed on the side of the pad mounting ring (7) away from the mounting ring boss (8).

6. The thrust bearing for a steam turbine as set forth in claim 5, characterized by It also includes a mounting pin (14). The tile mounting ring (7) has an inner mounting hole (15) and an outer mounting hole (16) on the side away from the mounting ring boss (8). The thrust tile (11) has an inner mounting hole (17) and an outer mounting hole (18). A mounting pin (14) is provided between the inner mounting hole (15) and the inner mounting hole (17) of the tile and between the outer mounting hole (16) and the outer mounting hole (18) of the tile.

7. The thrust bearing for a steam turbine as set forth in claim 6, characterized by The thrust pad (11) is provided with a pad support block (19) on the side facing the pad mounting ring (7).

8. The thrust bearing for a steam turbine as set forth in claim 1, characterized by The strain detector (10) is a resistance strain gauge.

9. The thrust bearing for a steam turbine as set forth in claim 4, characterized by The tile mounting ring (7), the mounting ring boss (8), the first reinforcing rib (12), and the second reinforcing rib (13) are integrally formed.

10. The thrust bearing for a steam turbine as set forth in claim 1, characterized by The positive thrust bearing (5) and the negative thrust bearing (6) are also equipped with resistance temperature detectors (20).

Images