Turning gear with gear variable-frequency meshing function

Abstract

The invention discloses a turning gear with a gear variable-frequency meshing function, belongs to the field of steam turbines, and aims to solve the problem of tooth beating in the meshing process of a turning system. The system comprises a reduction gear box, a meshing pinion, a turning motor, a PLC controller, a frequency converter, a rotating speed sensor and an encoder. The turning motor is arranged on the upper portion of the reduction gear box and connected with an input shaft of the reduction gear box, and an output shaft of the reduction gear box drives the meshing pinion to rotate. The encoder is used for monitoring a rotating speed signal of the turning motor and feeding back the rotating speed signal to the frequency converter in real time to form closed-loop control so as to control the gear meshing rotating speed; the rotating speed sensor is used for monitoring a rotating speed signal of a large gear of the steam turbine and feeding back the rotating speed signal to the PLC, and the PLC changes the running speed of the barring motor through the frequency converter so that the barring motor can output the steam turbine barring rotating speed; and then the meshing pinion is driven to axially move to be meshed with the turbine bull gear, and turbine turning is achieved.

Description

Technical Field

[0001] The invention relates to a turning device of a steam turbine and belongs to the field of steam turbines. Background Art

[0002] As we all know, power generation in power plants is mainly achieved by steam turbines driving generators. However, since the steam turbine is usually in a cold state before starting, the temperature inside the cylinder and bearings is relatively low. Before the turbine is started, it needs to deliver high-temperature shaft seal steam and evacuate the steam turbine. After the high-temperature shaft seal steam enters the shaft seal and the cylinder, a temperature difference will be formed, which is hot at the top and cold at the bottom, which can easily cause equipment failures such as cylinder deformation and rotor bending. Similarly, the steam turbine is in a hot state after shutdown, and the residual heat of the cylinder will also cause large temperature differences between the upper and lower cylinders and thermal bending of the rotor to the rotor and cylinder. Therefore, it is of utmost importance to turn the turbine before starting and after stopping to avoid deformation of mechanical equipment due to uneven thermal stress.

[0003] With the continuous development of science and technology and continuous innovation in the field of automation technology, the original manual cranking method is no longer suitable for development needs due to its high labor intensity, low safety and efficiency. Conventional electric cranking uses a soft starter to change the initial voltage and boost time to control the motor operation, and cannot accurately control the low speed operation of the cranking motor. As a result, during the cranking engagement process, the speed difference between the meshing gear and the large gear of the turbine is too large, resulting in tooth playing, which ultimately leads to unsuccessful cranking engagement and inability to crank, greatly reducing the cranking reliability. Summary of the invention

[0004] In order to solve the problem of tooth playing during the meshing process of a cranking system, the present invention provides a cranking device with variable frequency gear meshing.

[0005] The present invention discloses a cranking device with gear frequency conversion meshing, comprising a reduction gear box 1, a meshing pinion 2, a cranking motor 3, a PLC controller 6, a frequency converter 8, a speed sensor 9 and an encoder 13;

[0006] The turning motor 3 is arranged on the upper part of the reduction gear box 1, and the turning motor 3 is connected to the input shaft of the reduction gear box 1, and the output shaft of the reduction gear box 1 drives the meshing pinion 2 to rotate;

[0007] The encoder 13 is used to monitor the speed signal of the turning motor 3 and feed it back to the frequency converter 8 in real time to form a closed-loop control, thereby controlling the gear meshing speed;

[0008] The speed sensor 9 is used to monitor the speed signal of the turbine gear 12 and feed it back to the PLC controller 6. The PLC controller 6 changes the running speed of the cranking motor 3 through the frequency converter 8 so that the cranking motor 3 outputs the turbine cranking speed; and then drives the meshing pinion 2 to move axially and mesh with the turbine gear 12 to realize the turbine cranking.

[0009] Preferably, it also includes a meshing valve 4 and a lubricating oil supply valve 5, which are arranged on the reduction gearbox 1. The meshing valve 4 is used to control the meshing of the turbine gear 12 with the meshing pinion 2; the lubricating oil supply valve 5 is used to provide meshing oil for the meshing.

[0010] Preferably, it also includes an engagement detection switch 10 and a disengagement detection switch 11, which are arranged on the reduction gearbox 1, and the engagement detection switch 10 is used to detect whether the meshing pinion 2 is in a fully meshed position with the turbine gear 12; the disengagement detection switch 11 is used to detect whether the meshing pinion 2 is in a fully disengaged position with the turbine gear 12.

[0011] Preferably, it also includes a human-machine interaction unit 7, which is used for state monitoring, parameter setting and test data query of the turning gear, and real-time signal interaction with the PLC controller 6.

[0012] Preferably, the speed sensor 9 monitors the speed signal of the turbine gear 12. If the speed is zero, it is judged that the turbine is currently in a stationary state, and the PLC controller 6 performs static cranking; if the speed is greater than zero, it is judged that the turbine is currently in an operating state, and the PLC controller 6 performs dynamic cranking.

[0013] Preferably, the static cranking process is as follows: the PLC controller 6 opens the lubrication oil supply valve 5 and the meshing valve 4 in sequence, and the meshing oil pushes the meshing pinion to the meshing surface with the turbine gear 12. At this time, the frequency converter 8 drives the cranking motor 3 to output a lower speed V1, driving the meshing pinion 2 to rotate, and under the thrust of the meshing oil, the meshing pinion 2 engages with the turbine gear 12; when the detection switch 10 detects that the meshing pinion is in place, the frequency converter 8 drives the cranking motor 3 to increase the speed to the rated speed of the cranking motor 3. At this time, the control system cuts off the motor output of the frequency converter 8, switches the cranking motor 3 to industrial frequency operation, completes the static cranking, and enables the cranking device to control the operating state of the turbine.

[0014] Preferably, the dynamic cranking process is as follows: when the disengagement detection switch 11 detects that the meshing pinion 2 is in the fully disengaged position, the oil supply valve 5 is opened, and the PLC controller 6 executes the power frequency operation of the cranking motor 3, and the meshing pinion 2 rotates and stands by in the fully disengaged position. At this time, the speed sensor 9 detects the speed of the turbine gear 12 in real time. When the speed is within ±0.5r / min of the speed of the cranking meshing pinion 2, the meshing valve 4 is opened, and the meshing oil pushes the meshing pinion 2 toward the turbine gear 12 for gear meshing. When the combination detection switch 10 detects that the meshing pinion is in place, the meshing valve 4 is closed to complete the dynamic cranking, so that the cranking device controls the operating state of the turbine; when the turbine speed is greater than the speed of the meshing pinion 2, the meshing pinion 2 is automatically thrown away from the turbine gear 12 until it reaches the fully disengaged position, the cranking stops automatically, and the system closes the lubrication supply valve 5.

[0015] Preferably, the lower rotation speed V1 is 5 r / min to 15 r / min.

[0016] Beneficial effects of the present invention: The present invention adopts a frequency converter to control the operation of the turning motor in a closed loop, which greatly improves the control accuracy of the turning speed and perfectly solves the problem of tooth playing during the meshing process of the turning system. The control system provided by the present invention realizes precise control of the turning motor speed by adopting a frequency converter, especially can realize accurate gear meshing at low speed, effectively avoids the phenomenon of tooth playing during the meshing process of the turning system, and greatly improves the efficiency, reliability and stability of the turning system. In addition, the system can perform static turning and dynamic turning of the turbine, enhances the flexibility of the turning system application, and fully meets the different turning requirements of nuclear power. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a turning device with variable frequency gear meshing according to the present invention;

[0018] Figure 2 It is a control block diagram of a turning gear with variable frequency gear meshing as described in the invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0022] Specific implementation method 1: The following is combined Figure 1 and Figure 2 This embodiment is described. The cranking device with gear frequency conversion meshing described in this embodiment includes a mechanical system and a control system. The mechanical system includes a reduction gear box 1, a meshing pinion 2, a cranking motor 3, a meshing valve 4, and a lubrication oil supply valve 5; the control system includes a PLC controller 6, a human-machine interaction unit 7, a frequency converter 8, a speed sensor 9, a combination detection switch 10, and a disengagement detection switch 11;

[0023] The cranking motor 3 is the power driving source of the cranking system and is arranged on the upper part of the reduction gearbox 1; the cranking motor 3 is connected to the input shaft of the reduction gearbox 1, and the output shaft of the reduction gearbox 1 drives the meshing pinion 2 to rotate; the meshing pinion 2 can axially move and mesh with the turbine gear 12 to realize turbine cranking;

[0024] The reduction gearbox 1 reduces the speed of the cranking motor 3 to the turbine cranking speed, that is, the speed of the turbine gear 12;

[0025] The PLC controller 6 is the core of the system logic control, and performs the cranking action according to the control command, parameters and speed of the human-machine interaction unit 7;

[0026] The human-machine interaction unit 7 is used for status monitoring, parameter setting, test data query, etc. of the turning system, and real-time signal interaction with the PLC controller 6.

[0027] The frequency converter 8 is used to change the running speed of the turning motor 3;

[0028] The encoder 13 detects the speed of the turning motor 3 and is arranged at the tail of the motor and connected to the motor. The motor speed signal is fed back to the frequency converter 8 in real time to form a closed-loop control, thereby being able to accurately control the gear meshing speed.

[0029] The combination detection switch 10 is used to detect whether the meshing pinion 2 is in a fully meshing position with the turbine gear 12;

[0030] The disengagement detection switch 11 is used to detect whether the meshing pinion 2 is in a completely disengaged position from the turbine gear 12;

[0031] The speed sensor 9 detects the operating status of the turbine, detects the speed of the turbine gearwheel in real time, and determines whether the turbine is currently in a static state or a dynamic state; the speed sensor 9 monitors the speed signal of the turbine gearwheel 12. If the speed is zero, it is determined that the turbine is currently in a static state, and the PLC controller 6 executes static cranking; if the speed is greater than zero, it is determined that the turbine is currently in an operating state, and the PLC controller 6 executes dynamic cranking.

[0032] If it is static, the system will execute static cranking after startup; if it is dynamic, the system will execute dynamic cranking.

[0033] The process of static cranking is as follows: the PLC controller 6 opens the lubrication oil supply valve 5 and the meshing valve 4 in sequence, and the meshing oil pushes the meshing pinion to the meshing surface with the turbine gear 12. At this time, the frequency converter 8 drives the cranking motor 3 to output a lower speed V1, driving the meshing pinion 2 to rotate, and under the thrust of the meshing oil, the meshing pinion 2 engages with the turbine gear 12; when the detection switch 10 detects that the meshing pinion is in place, the frequency converter 8 drives the cranking motor 3 to increase the speed to the rated speed of the cranking motor 3. At this time, the control system cuts off the motor output of the frequency converter 8, switches the cranking motor 3 to industrial frequency operation, completes the static cranking, and enables the cranking device to control the operating status of the turbine.

[0034] The lower rotation speed V1 is 5 r / min to 15 r / min.

[0035] The process of dynamic cranking is as follows: when the disengagement detection switch 11 detects that the meshing pinion 2 is in the fully disengaged position, the oil supply valve 5 is opened, and the PLC controller 6 executes the power frequency operation of the cranking motor 3, and the meshing pinion 2 rotates and stands by in the fully disengaged position. At this time, the speed sensor 9 detects the speed of the turbine gear 12 in real time. When the speed is within ±0.5r / min of the speed of the meshing pinion 2 of the cranking, the meshing valve 4 is opened, and the meshing oil pushes the meshing pinion 2 toward the turbine gear 12 for gear meshing. When the detection switch 10 detects that the meshing pinion is in place, the meshing valve 4 is closed to complete the dynamic cranking, so that the cranking device controls the operation status of the turbine. When the turbine speed is greater than the speed of the meshing pinion 2, the meshing pinion 2 is automatically thrown away from the turbine gear 12 until it reaches the fully disengaged position, the cranking stops automatically, and the system closes the lubrication supply valve 5.

[0036] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A gear turning device with variable frequency meshing of gears, characterized in that: It comprises a reduction gear box (1), a meshing pinion (2), a turning motor (3), a PLC controller (6), a frequency converter (8), a speed sensor (9) and an encoder (13); The turning motor (3) is arranged on the upper part of the reduction gear box (1), the turning motor (3) is connected to the input shaft of the reduction gear box (1), and the output shaft of the reduction gear box (1) drives the meshing pinion (2) to rotate; The encoder (13) is used to monitor the speed signal of the turning motor (3) and feed it back to the frequency converter (8) in real time to form a closed-loop control, thereby controlling the gear meshing speed; The speed sensor (9) is used to monitor the speed signal of the turbine gear (12) and feed it back to the PLC controller (6). The PLC controller (6) changes the running speed of the cranking motor (3) through the frequency converter (8) so that the cranking motor (3) outputs the turbine cranking speed; and then drives the meshing pinion (2) to move axially and mesh with the turbine gear (12), thereby realizing turbine cranking.

2. A barring device with variable frequency gear meshing according to claim 1, characterized in that: The invention also comprises a meshing valve (4) and a lubricating oil supply valve (5), wherein the meshing valve (4) and the lubricating oil supply valve (5) are arranged on the reduction gear box (1), the meshing valve (4) is used to control the meshing of the turbine gear (12) and the meshing pinion (2), and the lubricating oil supply valve (5) is used to provide meshing oil for the meshing.

3. A barring device with variable frequency gear meshing according to claim 2, characterized in that: The invention also comprises an engagement detection switch (10) and a disengagement detection switch (11), wherein the engagement detection switch (10) and the disengagement detection switch (11) are arranged on the reduction gear box (1), wherein the engagement detection switch (10) is used to detect whether the meshing pinion gear (2) is in a completely meshing position with the large gear (12) of the steam turbine; and the disengagement detection switch (11) is used to detect whether the meshing pinion gear (2) is in a completely disengaged position with the large gear (12) of the steam turbine.

4. A barring device with variable frequency gear meshing according to claim 3, characterized in that: It also comprises a human-machine interaction unit (7), which is used for monitoring the state of the turning gear, setting parameters and querying test data, and for real-time signal interaction with the PLC controller (6).

5. A barring device with variable frequency gear meshing according to claim 3, characterized in that: The speed sensor (9) monitors the speed signal of the turbine gear (12). If the speed is zero, it is determined that the turbine is currently in a stationary state, and the PLC controller (6) performs static cranking. If the rotation speed is greater than zero, it is determined that the steam turbine is currently in operation, and the PLC controller (6) performs dynamic cranking.

6. A barring device with variable frequency gear meshing according to claim 5, characterized in that: The static cranking process is as follows: the PLC controller (6) opens the lubrication oil supply valve (5) and the meshing valve (4) in sequence, and the meshing oil pushes the meshing pinion to the meshing surface with the turbine gear (12). At this time, the frequency converter (8) drives the cranking motor (3) to output a relatively low speed V1, driving the meshing pinion (2) to rotate. Under the thrust of the meshing oil, the meshing pinion (2) and the turbine gear (12) perform gear meshing. When the detection switch (10) detects that the meshing pinion is in place, the frequency converter (8) drives the cranking motor (3) to increase the speed to the rated speed of the cranking motor (3). At this time, the control system cuts off the motor output of the frequency converter (8), switches the cranking motor (3) to power frequency operation, completes the static cranking, and enables the cranking device to control the turbine operation state.

7. A barring device with variable frequency gear meshing according to claim 1, characterized in that: The process of dynamic cranking is as follows: when the disengagement detection switch (11) detects that the meshing pinion (2) is in the fully disengaged position, the oil supply valve (5) is opened, and the PLC controller (6) executes the cranking motor (3) to operate at the industrial frequency, and the meshing pinion (2) rotates and waits in the fully disengaged position. At this time, the speed sensor (9) detects the speed of the turbine gear (12) in real time. When the speed is within ±0.5r / min of the speed of the cranking meshing pinion (2), the meshing valve (4) is opened, and the meshing The oil pushes the meshing pinion (2) toward the turbine gear (12) to mesh the gears. When the detection switch (10) detects that the meshing pinion is in place, the meshing valve (4) is closed to complete the dynamic cranking, so that the cranking device controls the turbine operation state. When the turbine speed is greater than the speed of the meshing pinion (2), the meshing pinion (2) is automatically thrown away from the turbine gear (12) until it reaches the completely disengaged position, the cranking stops automatically, and the system closes the lubrication oil supply valve (5).

8. A barring device with variable frequency gear meshing according to claim 6, characterized in that: The lower rotation speed V1 is 5 r / min to 15 r / min.

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