A turbine turning gear control system

Abstract

The application discloses a turbine disc turning control system, and disc turning control loop comprises disc turning motor, pin pulling starting circuit, zero speed control circuit, pin pulling proceeding circuit, handle action circuit, pin pulling ending circuit, gear contact circuit, stop retreating handle circuit, disc turning motor reverse rotation circuit, instantaneous action mode circuit, instantaneous action logic circuit, motor instantaneous action intermittent disc turning circuit and disc turning inspection circuit. The application re-designs the disc turning control loop, adds multiple relays and time relays in the disc turning control loop, ensures reliable execution of the control logic, ensures reliable triggering of the disc turning exit through the zero speed control circuit, ensures reliable triggering through the KL3 angular travel switch, and adds the disc turning control loop into the DCS monitoring picture, so that the operation operator can monitor the turbine disc turning operation and switching on / off on the DCS picture.

Description

Technical Field

[0001] This invention relates to the field of steam turbine technology, and more specifically to a steam turbine turning gear control system. Background Technology

[0002] The turning gear mechanism of a steam turbine is a device used to continuously rotate the rotor at a certain speed after the turbine is shut down and before it is started, ensuring uniform heating and cooling of the rotor. Turning the rotor before startup can be used to check whether the turbine meets operating conditions, such as whether there is friction between moving and stationary parts, and whether the main shaft bending is normal. After shutdown, engaging the turning gear mechanism can agitate the steam flow within the cylinder, helping to eliminate temperature differences between the upper and lower parts of the cylinder, preventing rotor deformation, and helping to eliminate damage to the bearings from hot journals.

[0003] The existing turning gear mechanism is a product supplied to the main engine manufacturer. The turbine uses low-speed turning gear, with a turning speed of 3 r / min, and has both automatic and manual operation modes. Due to design imperfections, the turbine turning gear control mechanism (see...) Figure 1 The following problems have persisted: 1. The logic for automatically engaging the turning gear under "zero speed judgment" cannot be implemented in the original control diagram, therefore the initial conditions for automatic turning gear engagement are not met; 2. Reliable sequential execution from the KL2 closed loop to the KL3 closed loop cannot be achieved, therefore operators must manually rotate the turning gear mechanism to the meshing position and then directly start the turning gear motor to engage the turning gear, which carries certain risks; 3. The turning gear position switch KL3 is a key component ensuring the normal operation of the turning gear mechanism. Misoperation may cause rubbing between the pinion gear and the turning gear motor gear; failure to operate will cause the turning gear mechanism to disengage; if not handled in time, it may cause the turbine shaft to bend, leading to an irreversible accident. Due to its design flaws, the position switch KL3 frequently malfunctions during turbine shutdown and start-up, often resulting in the turning gear failing to engage or the turning gear motor running idle; 4. During turbine turning, if a turning gear disengagement event occurs, the imperfect automatic turning gear engagement function will prevent the turbine from turning, which, if not detected in time, will cause a serious accident. Summary of the Invention

[0004] The technical solution adopted by this invention to solve the technical problem is: a steam turbine turning gear control system, comprising: a turning gear control circuit, wherein the turning gear control circuit is electrically connected to a DCS monitoring screen, and the turning gear control circuit includes a turning gear motor, a pin-pulling start circuit, a zero-speed control circuit, a pin-pulling operation circuit, a handle action circuit, a pin-pulling end circuit, a gear contact circuit, a stop handle retraction circuit, a turning gear motor reversal circuit, an instantaneous mode circuit, an instantaneous logic circuit, a motor instantaneous intermittent turning gear circuit, a turning gear check circuit, a turning gear operation circuit, a delayed ratio air source circuit, a prohibition circuit, and a lubricating oil pressure check circuit. The circuit includes a power indicator XD0 circuit for the turning motor connected to the neutral wire via a three-phase power supply. The turning motor is also electrically connected to a transmitter via a three-phase circuit. The circuit includes a turning motor, a pin-pulling start circuit, a zero-speed control circuit, a pin-pulling operation circuit, a handle action circuit, a pin-pulling end circuit, a gear contact circuit, a stop handle retraction circuit, a turning motor reverse circuit, an instantaneous mode circuit, an instantaneous logic circuit, a motor instantaneous intermittent turning circuit, a turning check circuit, a turning operation circuit, a delayed ratio air source circuit, a prohibition circuit, and a lubricating oil pressure check circuit, all connected in parallel between the three-phase circuit and the ground wire circuit.

[0005] The pin-pulling end circuit, gear contact circuit, and stop handle retraction circuit are connected in parallel, and the parallel circuit of the pin-pulling end circuit, gear contact circuit, and stop handle retraction circuit is controlled by limit switch KL1 to open and close the circuit.

[0006] The gear contact circuit is equipped with a linear travel switch KL2, which controls the circuit's on / off state.

[0007] The pin-pulling circuit and the handle action circuit are connected in parallel. The parallel circuit of the pin-pulling circuit and the handle action circuit is controlled by switch 1J to open and close the circuit. The handle action circuit is equipped with switch 3J.

[0008] The turning circuit and the delayed shut-off air source circuit are also controlled by KL3 and switches 9J, 7QA and 7J; KL3 is an angle limit switch, used to replace the old linear limit switch KL3.

[0009] As a preferred embodiment of the present invention, the turning gear control circuit further includes a pin-in-position indicator XD2 circuit, a pin-not-moved indicator XD4 electric circuit, a gear contact indicator XD6 circuit, a turning gear running indicator XD8 circuit, a motor overcurrent indicator XD10 circuit, and a prohibition-from-rotation indicator XD12 circuit. The pin-in-position indicator XD2 circuit, the pin-not-moved indicator XD4 electric circuit, the gear contact indicator XD6 circuit, the turning gear running indicator XD8 circuit, the motor overcurrent indicator XD10 circuit, and the prohibition-from-rotation indicator XD12 circuit are connected in parallel between the three-phase circuit and the ground circuit.

[0010] As a preferred embodiment of the present invention, a switch 5QA is provided between the instantaneous mode circuit and the instantaneous logic circuit, a switch 4J is provided in the instantaneous mode circuit, and a switch 6J is provided in the instantaneous logic circuit.

[0011] As a preferred embodiment of the present invention, the turning gear circuit is equipped with a switch 8J, the turning gear circuit and the delayed shut-off air source circuit are connected in parallel, the parallel circuit of the turning gear circuit and the delayed shut-off air source circuit is connected in parallel with the main circuit, and the circuit is controlled by switch 5J and button switch QC.

[0012] The present invention has the following advantages: by redesigning the turning gear control circuit and adding multiple relays and time relays to the turning gear control circuit, the reliable execution of the sequential control logic is ensured; the zero-speed control circuit ensures reliable triggering when the turning gear exits; the KL3 angle limit switch ensures reliable triggering; and the turning gear control circuit is added to the DCS monitoring screen, ensuring that the operation and duty personnel can monitor the operation and engagement / disengagement of the turbine turning gear on the DCS screen. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the operating principle of an existing manual turning system;

[0014] Figure 2 This is a schematic diagram of the wiring of the turbine turning gear control cabinet according to a preferred embodiment of the present invention. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0016] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Please refer to the following: Figure 2This invention discloses a turbine turning control system, comprising: a turning control circuit electrically connected to a DCS monitoring screen; the turning control circuit includes a turning motor, a pin-pulling start circuit, a zero-speed control circuit, a pin-pulling operation circuit, a handle action circuit, a pin-pulling end circuit, a gear contact circuit, a stop handle retraction circuit, a turning motor reversal circuit, an instantaneous mode circuit, an instantaneous logic circuit, a motor instantaneous intermittent turning circuit, a turning check circuit, a turning operation circuit, a delayed ratio air source circuit, a prohibition circuit, and a lubricating oil pressure check circuit; the turning motor is electrically connected to a power indicator light X via three-phase power and a neutral wire. The D0 circuit, through the power indicator XD0 circuit, facilitates identification of whether the turning motor is running. The turning motor is electrically connected to a transmitter via a three-phase circuit. The transmitter can boost the voltage through the circuit. The turning motor, pin pulling start circuit, zero speed control circuit, pin pulling process circuit, handle action circuit, pin pulling end circuit, gear contact circuit, stop handle retraction circuit, turning motor reverse circuit, instantaneous mode circuit, instantaneous logic circuit, motor instantaneous intermittent turning circuit, turning check circuit, turning process circuit, delayed ratio air source circuit, anti-rush circuit, and lubricating oil pressure check circuit are connected in parallel between the three-phase circuit and the ground circuit.

[0018] The turning gear control circuit includes circuits for: pin engaged indicator XD2, pin not engaged indicator XD4 (electric), gear contact indicator XD6, turning gear running indicator XD8, motor overcurrent indicator XD10, and prohibition of over-rotation indicator XD12. These circuits are connected in parallel between the three-phase circuit and the ground circuit. The indicator light in the pin engaged indicator XD2 circuit allows for remote and on-site identification of whether the pin is engaged. Similarly, the indicator light in the pin not engaged indicator XD4 (electric) helps identify whether the pin has been engaged. The indicator light in the gear contact indicator XD6 circuit helps identify whether the gears are in contact. The indicator light in the turning gear running indicator XD8 circuit helps identify whether the turning gear is running. The indicator light in the motor overcurrent indicator XD10 circuit helps identify whether the motor is experiencing overcurrent. The indicator light in the prohibition of over-rotation indicator XD12 circuit helps identify whether over-rotation has occurred.

[0019] The pin-pulling termination circuit, gear contact circuit, and stop / retract handle circuit are connected in parallel. The entire parallel circuit of these circuits is controlled by a linear travel switch KL1. A linear travel switch KL2 is included in the gear contact circuit. The pin-pulling operation circuit and handle operation circuit are connected in parallel. The entire parallel circuit of these two circuits is controlled by switch 1J. A switch 3J is included in the handle operation circuit. The instantaneous operation mode circuit and instantaneous operation logic are also included. A switch 5QA is installed between the circuits. A switch 4J is installed in the instantaneous mode circuit. A switch 6J is installed in the instantaneous logic circuit. A switch 8J is installed in the turning gear circuit. The turning gear circuit and the delayed shut-off air source circuit are connected in parallel. The parallel circuit of the turning gear circuit and the delayed shut-off air source circuit is connected in parallel with the total circuit. The circuit is controlled by switch 5J and push switch QC. The turning gear circuit and the delayed shut-off air source circuit are also controlled by angle travel switch KL3 and switches 9J, 7QA and 7J.

[0020] In summary, the turning gear control circuit adds multiple relays and time relays to ensure reliable execution of the sequential control logic. The zero-speed control circuit ensures reliable triggering when the turning gear is withdrawn. The turning gear control circuit is also added to the DCS monitoring screen to ensure that the operation and withdrawal status of the turbine turning gear can be monitored by the operation personnel on the DCS screen.

[0021] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0022] Other parts of this invention that are not detailed herein are all prior art and will not be described further here.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A turbine turning gear control system, comprising: A turning gear control circuit, characterized in that the turning gear control circuit is electrically connected to a DCS monitoring screen, and the turning gear control circuit includes a turning gear motor, a pin-pulling start circuit, a zero-speed control circuit, a pin-pulling operation circuit, a handle action circuit, a pin-pulling end circuit, a gear contact circuit, a stop handle retraction circuit, a turning gear motor reversal circuit, an instantaneous mode circuit, an instantaneous logic circuit, a motor instantaneous intermittent turning gear circuit, a turning gear check circuit, a turning gear operation circuit, a delayed ratio air source circuit, a prohibition circuit, and a lubricating oil pressure check circuit. The turning gear motor is powered by three-phase electricity. A power indicator XD0 circuit is electrically connected to the neutral wire. The turning motor is electrically connected to a transmitter through a three-phase circuit. The turning motor, pin pulling start circuit, zero speed control circuit, pin pulling process circuit, handle action circuit, pin pulling end circuit, gear contact circuit, stop handle retraction circuit, turning motor reverse circuit, instantaneous mode circuit, instantaneous logic circuit, motor instantaneous intermittent turning circuit, turning check circuit, turning process circuit, delayed ratio air source circuit, anti-rush circuit, and lubricating oil pressure check circuit are connected in parallel between the three-phase circuit and the ground wire circuit. The pin-pulling end circuit, gear contact circuit, and stop handle retraction circuit are connected in parallel, and the parallel circuit of the pin-pulling end circuit, gear contact circuit, and stop handle retraction circuit is controlled by limit switch KL1 to open and close the circuit. The gear contact circuit is equipped with a linear travel switch KL2, which controls the circuit's on / off state. The pin-pulling circuit and the handle action circuit are connected in parallel. The parallel circuit of the pin-pulling circuit and the handle action circuit is controlled by switch 1J to open and close the circuit. The handle action circuit is equipped with switch 3J. The turning circuit and the delayed shut-off air source circuit are also controlled by KL3 and switches 9J, 7QA and 7J; KL3 is an angle limit switch, used to replace the old linear limit switch KL3.

2. The turbine turning gear control system as described in claim 1, characterized in that, The turning gear control circuit also includes a pin-in-position indicator XD2 circuit, a pin-not-moved indicator XD4 electric circuit, a gear contact indicator XD6 circuit, a turning gear running indicator XD8 circuit, a motor overcurrent indicator XD10 circuit, and a prohibition-from-rotation indicator XD12 circuit. The pin-in-position indicator XD2 circuit, the pin-not-moved indicator XD4 electric circuit, the gear contact indicator XD6 circuit, the turning gear running indicator XD8 circuit, the motor overcurrent indicator XD10 circuit, and the prohibition-from-rotation indicator XD12 circuit are connected in parallel between the three-phase circuit and the ground circuit.

3. The turbine turning gear control system as described in claim 1, characterized in that, A switch 5QA is provided between the instantaneous mode circuit and the instantaneous logic circuit, a switch 4J is provided in the instantaneous mode circuit, and a switch 6J is provided in the instantaneous logic circuit.

4. The turbine turning gear control system as described in claim 1, characterized in that, The turning gear circuit is equipped with switch 8J. The turning gear circuit and the delayed shut-off air source circuit are connected in parallel. The parallel circuit of the turning gear circuit and the delayed shut-off air source circuit is connected in parallel with the main circuit and is controlled by switch 5J and button switch QC to open and close the circuit.

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