A steam turbine shaft vibration monitoring and protection device

Abstract

The application discloses a steam turbine shaft vibration monitoring and protecting device, which comprises a vibration monitoring module installed on the axial ends of a steam turbine main shaft, a circumferential data collector arranged in the middle of the steam turbine main shaft, and a processor connected with the vibration monitoring module and the circumferential data collector; the vibration monitoring module monitors the motion information of the axial ends of the steam turbine main shaft, and sends the collected motion information to the processor; the circumferential data collector collects rotation data of different positions in the middle of the steam turbine main shaft, and the vibration monitoring module sends the rotation data to the processor; the processor fits the motion information and the rotation data, compares them with the shaft vibration threshold value stored in the memory, and obtains a shaft vibration monitoring result. According to the motion information and the rotation data, whether the steam turbine is in shaft vibration is judged, the vibration monitoring module is installed on the axial ends of the main shaft, the circumferential data collector arranged in the middle of the main shaft is not in contact with the main shaft, the normal rotation of the main shaft and the normal use of the blades on the main shaft are not affected, and the steam turbine shaft vibration monitoring can be realized.

Description

Technical Field

[0001] This invention relates to the field of steam turbine monitoring, and more particularly to a steam turbine shaft vibration monitoring and protection device. Background Technology

[0002] Steam turbines are an important piece of equipment in my country's power plants today, serving as a crucial foundation for ensuring power supply. Steam turbine vibration is often influenced by a variety of factors; any component or medium related to the turbine can contribute to its vibration. Among these, turbine shaft vibration is one of the more complex types of turbine vibration faults.

[0003] Since turbine shaft vibration severely affects the normal operation of turbines, continuous monitoring of turbine shaft vibration, timely prevention, and early-stage maintenance are crucial. Chinese Patent Publication No. 103398770A discloses a main shaft vibration meter, consisting of a sensing device and a recording instrument. The sensing device comprises a metal ball, a metal box, a sensor, and a data cable. This patent uses the sensing device to measure and record the vibration of the main shaft during rotation.

[0004] Considering that the metal ball and metal box in the sensing device of the patent document are installed in the middle of the turbine main shaft, it would hinder the normal installation and operation of the turbine blades.

[0005] In view of this, it is necessary to improve the existing main shaft vibration meter in order to realize the vibration monitoring of the turbine shaft. Summary of the Invention

[0006] The purpose of this invention is to provide a turbine shaft vibration monitoring and protection device that determines whether the turbine is experiencing shaft vibration based on action information and rotation data. The vibration monitoring module is installed at both ends of the main shaft, and the circumferential data acquisition device located in the middle of the main shaft is not in contact with the main shaft. This does not affect the normal rotation of the main shaft or the normal use of the blades on the main shaft, and it can also realize turbine shaft vibration monitoring, which has the advantage of convenient monitoring.

[0007] This invention is achieved using the following technical solution:

[0008] A turbine shaft vibration monitoring and protection device includes: a vibration monitoring module installed at both ends of the turbine main shaft, a circumferential data acquisition device set in the middle of the turbine main shaft, and a processor connected to the vibration monitoring module and the circumferential data acquisition device;

[0009] The vibration monitoring module monitors the motion information at both ends of the turbine main shaft, and sends the collected motion information to the processor.

[0010] The circumferential data acquisition unit collects rotational data at different positions in the middle of the turbine main shaft, and the vibration monitoring module sends the rotational data to the processor.

[0011] The processor fits motion information and rotation data and compares them with the stored shaft vibration threshold to obtain shaft vibration monitoring results.

[0012] A further improvement of this invention is that, since single motion information or rotation data may lead to misjudgment, the vibration monitoring module is installed at both ends of the main shaft to determine whether the turbine is experiencing shaft vibration based on motion information and rotation data. The circumferential data acquisition unit located in the middle of the main shaft is not in contact with the main shaft, so it does not affect the normal rotation of the main shaft and the normal use of the blades on the main shaft, and can also realize the monitoring of turbine shaft vibration.

[0013] A further improvement of the present invention is that the vibration monitoring module includes: a connecting shaft connected to the flange at the axial end of the main shaft, an elastic bushing that wraps around the connecting shaft, an inert gas filled between the connecting shaft and the elastic bushing, and an airflow collector for collecting the flow of the inert gas, wherein the airflow collector is connected to the processor.

[0014] A further improvement of the present invention is that the turbine shaft vibration monitoring and protection device also includes a protection module, which is connected to the processing module.

[0015] A further improvement of the present invention is that the protection module is also connected to the vibration monitoring module, and the surface of the vibration monitoring module is squeezed to obtain information on overcoming axial vibration.

[0016] A further improvement of the present invention is that the outer peripheral wall of the elastic bushing is provided with several grids, and the protection module includes: an airbag provided on the outer peripheral wall of the elastic bushing, an inflation and deflation device for inflating the airbag to realize the compression vibration monitoring module, and the airbag is divided into several small airbag units corresponding to the several grids.

[0017] A further improvement of the present invention is that the circumferential data acquisition device includes at least two sets of data acquisition devices, each set of data acquisition devices includes multiple data acquisition bodies, the acquisition heads of the multiple data acquisition bodies are 3-5cm away from the turbine main shaft, and the multiple data acquisition bodies acquire the data of the distance between the acquisition heads and the turbine main shaft in real time to obtain circumferential data.

[0018] A further improvement of the present invention is that the included angle between adjacent data acquisition bodies is greater than 90°.

[0019] A further improvement of the present invention is that the data acquisition device is installed on the fixed ring, and part of the turbine impeller is also located inside the fixed ring. At least one airflow sensor is installed inside the fixed ring. The airflow sensor is connected to the processor. The airflow sensor acquires airflow data inside the fixed ring, and the processor makes a secondary judgment on the accuracy of the shaft vibration monitoring results based on the airflow data.

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

[0021] This invention determines whether a steam turbine experiences shaft vibration based on motion information and rotation data. The vibration monitoring module is installed at both ends of the main shaft, and the circumferential data acquisition device located in the middle of the main shaft does not contact the main shaft. This does not affect the normal rotation of the main shaft or the normal use of the blades on the main shaft, and it can also realize the monitoring of steam turbine shaft vibration, which has the advantage of convenient monitoring. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the present invention;

[0023] Figure 2 For the present invention Figure 1 Diagram of the A-axis circumferential data acquisition device;

[0024] Figure 3 For the present invention Figure 1 Diagram of the B-axis circumferential data acquisition device;

[0025] Figure 4 For the present invention Figure 1 Diagram of the C-axis circumferential data acquisition device;

[0026] Figure 5 For the present invention Figure 1 Diagram of the D-axis circumferential data acquisition device.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1-Airbag, 2-Elastic bushing, 3-Connecting shaft, 4-Main shaft, 5-Data acquisition body, 6-Fixing ring. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0030] Steam turbines are a crucial piece of equipment in my country's power plants, serving as a vital foundation for ensuring power supply. However, after a certain period of operation, vibrations may exceed safe limits, causing significant wear on critical components and leading to potential malfunctions and, ultimately, accidents of varying degrees, to the generator set. This invention employs shaft vibration monitoring to keep turbine vibrations within safe ranges during operation. If vibrations exceed these limits, the cause of the shaft vibration can be immediately identified and repaired.

[0031] like Figures 1 to 5As shown, the present invention provides a turbine shaft vibration monitoring and protection device, comprising: a vibration monitoring module installed at both ends of the turbine main shaft 4, a circumferential data acquisition device disposed in the middle of the turbine main shaft 4, and a processor connected to the vibration monitoring module and the circumferential data acquisition device; the vibration monitoring module monitors the motion information at both ends of the turbine main shaft 4, and sends the collected motion information to the processor; the circumferential data acquisition device collects rotational data at different positions in the middle of the turbine main shaft 4, and the vibration monitoring module sends the rotational data to the processor; the processor fits the motion information and rotational data and compares them with the shaft vibration threshold stored therein to obtain the shaft vibration monitoring result.

[0032] The processor of this invention fits motion information and rotation data by utilizing the characteristic that the amplitude of vibration of the turbine main shaft 4 decreases at a certain speed under vibration conditions to determine the critical speed of the main shaft when the amplitude dips. When the axial bending effect corresponding to the motion information is less than the rotational imbalance amount in the rotation data, the reduction in amplitude occurs below the critical speed of the main shaft 4; when the axial bending effect corresponding to the motion information is greater than the rotational imbalance amount, the reduction in amplitude occurs above the critical speed of the main shaft 4.

[0033] Since single motion information or rotation data may lead to misjudgment, this invention determines whether the turbine is experiencing shaft vibration based on motion information and rotation data. The vibration monitoring module is installed at both ends of the main shaft 4, and the circumferential data acquisition device located in the middle of the main shaft 4 is not in contact with the main shaft 4. This does not affect the normal rotation of the main shaft 4 or the normal use of the blades on the main shaft 4, and can also realize the monitoring of turbine shaft vibration, which has the advantage of convenient monitoring.

[0034] The elastic bushing 2 of the present invention allows inert gas to absorb vibration energy during shaft vibration. After absorbing vibration energy, the inert gas manifests as airflow fluctuation. The present invention uses an airflow collector to obtain airflow fluctuation data, and can also make the turbine main shaft 4 flexible and vibration-damping.

[0035] The vibration monitoring module of the present invention includes: a connecting shaft 3 connected to the flange at the axial end of the main shaft 4, an elastic bushing 2 covering the connecting shaft 3, an inert gas filling the space between the connecting shaft 3 and the elastic bushing 2, and an airflow collector for collecting the flow of the inert gas, wherein the airflow collector is connected to the processor.

[0036] The turbine shaft vibration protection module of this invention uses the inflation and deflation method of the small airbag unit in the airbag 1 of the protection module. It mainly starts from the installation stage to check the impact of vibration on the main shaft 4 during installation, thereby helping the turbine vibration to be within a safe range.

[0037] The turbine shaft vibration monitoring and protection device of the present invention further includes a protection module, which is connected to the processing module; the protection module is also connected to the vibration monitoring module, and the vibration monitoring module is pressed to obtain information on overcoming shaft vibration.

[0038] Considering that improper balance of rotating parts, steam inlet parameters, condensate, and lubricating oil all affect shaft vibration during installation, this invention employs a protection module that uses several small airbag units to replace and inflate the elastic bushing 2 while the main shaft 4 is vibrating, facilitating the worker's investigation of the vibration source.

[0039] The elastic bushing 2 of the present invention has several grids on its outer peripheral wall. The protection module includes: an air bladder 1 disposed on the outer peripheral wall of the elastic bushing 2, and an air inflation and deflation device for inflating the air bladder 1 to realize the compression vibration monitoring module. The air bladder 1 is divided into several small air bladder units corresponding to the several grids.

[0040] The circumferential data acquisition device of the present invention includes at least two sets of data acquisition devices. Each set of data acquisition devices includes multiple data acquisition bodies 5. The acquisition heads of the multiple data acquisition bodies 5 are 3-5 cm away from the turbine main shaft. The multiple data acquisition bodies 5 acquire data on the distance between the acquisition heads and the turbine main shaft in real time to obtain circumferential data. The included angle between adjacent data acquisition bodies 5 is greater than 90°.

[0041] In cases where the rotor bends or the turbine blades break during shaft vibration monitoring, a significant asymmetry in the rotor's mass distribution can occur, leading to shaft vibration in the unit. To prevent these issues, this invention installs an airflow sensor within the fixed ring 6 to monitor airflow and prevent such occurrences.

[0042] The data acquisition device of the present invention is installed in the fixed ring 6, and part of the turbine impeller is also located in the fixed ring 6. At least one airflow sensor is installed in the fixed ring 6. The airflow sensor is connected to the processor. The airflow sensor acquires the airflow data in the fixed ring 6. The processor makes a secondary judgment on the accuracy of the shaft vibration monitoring result based on the airflow data.

Claims

1. A turbine shaft vibration monitoring and protection device, characterized in that, include: Vibration monitoring modules installed at both ends of the turbine main shaft, a circumferential data acquisition device located in the middle of the turbine main shaft, and a processor connected to the vibration monitoring modules and the circumferential data acquisition device; The vibration monitoring module monitors the motion information at both ends of the turbine main shaft and sends the collected motion information to the processor. The vibration monitoring module includes: a connecting shaft connected to the flange at the axial end of the main shaft, an elastic bushing that wraps the connecting shaft, an inert gas filled between the connecting shaft and the elastic bushing, and an airflow collector that collects the flow of the inert gas. The airflow collector is connected to the processor. The circumferential data acquisition unit collects rotational data at different positions in the middle of the turbine main shaft, and then sends the rotational data to the processor. The processor fits motion information and rotation data and compares them with the stored shaft vibration threshold to obtain shaft vibration monitoring results; The turbine shaft vibration monitoring and protection device also includes a protection module, which is connected to the processing module; The outer peripheral wall of the elastic bushing is provided with several grids. The protection module includes: an air bladder set on the outer peripheral wall of the elastic bushing, and an inflation and deflation device for inflating the air bladder to realize the compression vibration monitoring module. The air bladder is divided into several small air bladder units corresponding to the several grids.

2. The turbine shaft vibration monitoring and protection device according to claim 1, characterized in that, The protection module is also connected to the vibration monitoring module, and the surface of the vibration monitoring module is squeezed to obtain information on overcoming axial vibration.

3. The turbine shaft vibration monitoring and protection device according to claim 1, characterized in that, The circumferential data acquisition unit includes at least two sets of data acquisition units. Each set of data acquisition units includes multiple data acquisition bodies. The acquisition heads of the multiple data acquisition bodies are 3-5 cm away from the turbine main shaft. The multiple data acquisition bodies acquire the data on the distance between the acquisition heads and the turbine main shaft in real time to obtain circumferential data.

4. The turbine shaft vibration monitoring and protection device according to claim 3, characterized in that, The included angle between adjacent data acquisition bodies is greater than 90°.

5. The turbine shaft vibration monitoring and protection device according to claim 4, characterized in that, The data acquisition unit is installed on the fixed ring, and part of the turbine impeller is also located inside the fixed ring. At least one airflow sensor is installed inside the fixed ring. The airflow sensor is connected to the processor. The airflow sensor acquires airflow data inside the fixed ring, and the processor makes a secondary judgment on the accuracy of the shaft vibration monitoring results based on the airflow data.

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