Emergency power supply system of nuclear power station

Abstract

The utility model provides an emergency power supply system of a nuclear power station, which comprises a compressed air tank used for providing compressed air; the generator set comprises a starting motor, a diesel engine and a generator; the starting valve group comprises a main starting valve, is connected to a main pipeline between the compressed air tank and the starting motor and is used for driving a gear of the starting motor to rotate through compressed air; the starting electromagnetic valve is connected to the secondary pipeline between the compressed air tank and the starting motor; the starting electromagnetic valve is electrically connected with the storage battery pack; and the manual starting valve is connected to the spare pipeline between the compressed air tank and the starting motor. According to the emergency power supply system of the nuclear power station provided by the utility model, the generator set can be started under the condition that the storage battery pack fails.

Description

Technical Field

[0001] This utility model relates to the field of nuclear power, and in particular to an emergency power supply system for a nuclear power plant. Background Technology

[0002] The emergency power supply system of a nuclear power plant is a crucial safeguard for the safety of the units. Its core lies in the ability of emergency diesel generators to quickly start and continuously supply power in the event of a plant-wide power outage. Emergency diesel generators generally employ a compressed air-driven starting mode: when normal power is lost, the diesel engine is started by releasing pre-stored high-pressure air, and power is supplied to safe-level loads once the generator establishes voltage.

[0003] The generator set's control unit, excitation system, protection devices, and other critical subsystems all require continuous DC power, which is supplied by the battery bank. Although the battery bank is equipped with redundancy and a regular maintenance mechanism, under extreme accident conditions (such as prolonged plant-wide power outages, battery aging and failure, or accidental damage), battery depletion will directly lead to control system failure. In this situation, even if the compressed air system is intact, the diesel engine will still be unable to complete the starting sequence. When the battery bank cannot provide the necessary power, the diesel engine will completely lose its starting capability, directly causing the emergency power system to malfunction. Therefore, there are areas for improvement. Utility Model Content

[0004] The purpose of this invention is to provide an emergency power supply system for nuclear power plants that can start the generator set in the event of battery failure.

[0005] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:

[0006] This utility model provides an emergency power supply system for a nuclear power plant, comprising:

[0007] Compressed air tank, used to supply compressed air;

[0008] A generator set includes a starter motor, a diesel engine, and a generator connected in sequence. The diesel engine is used to drive the generator and provide power to the outside world.

[0009] A starter valve assembly is connected to the pipeline between the compressed air tank and the starter motor, and the starter valve assembly includes:

[0010] The main start valve is connected to the main pipeline between the compressed air tank and the starter motor, and is used to drive the gear of the starter motor to rotate by compressed air;

[0011] A solenoid valve is connected to a secondary pipeline between the compressed air tank and the starter motor, and is used to drive the gear of the starter motor to mesh with the flywheel of the diesel engine via compressed air; the solenoid valve is electrically connected to the battery pack.

[0012] At least one manual start valve is connected to a spare pipe between the compressed air tank and the starter motor, for using compressed air to drive the gear of the starter motor to mesh with the flywheel of the diesel engine; each spare pipe corresponds to one manual start valve.

[0013] In one embodiment of this utility model, the secondary pipe is connected to the air inlet of the backup pipe and is also connected to the main start valve.

[0014] In one embodiment of this utility model, the secondary pipeline is connected to the compressed air tank, and the backup pipeline is connected to the compressed air tank.

[0015] In one embodiment of this utility model, an excitation module is further included, the excitation module comprising:

[0016] A permanent magnet motor, connected to the rotating end of the generator, is used to provide AC power.

[0017] An excitation device is electrically connected between the permanent magnet generator and the generator. It is used to convert the AC power supply into an excitation power supply and to deliver the excitation power supply to the generator. The generator provides power to the outside world based on the excitation power supply.

[0018] In one embodiment of this utility model, the excitation module further includes an automatic excitation switch, which is electrically connected between the excitation device and the generator.

[0019] In one embodiment of the present invention, the excitation module further includes at least one manual excitation switch, which is electrically connected between the excitation device and the generator.

[0020] In one embodiment of this utility model, the manual trip switch includes a contactor and an auxiliary contact module. The contactor is model ABB AL16-30-10, and the auxiliary contact module is model CA5-10 / CA5-1.

[0021] In one embodiment of the present invention, an electronic speed governor is further included, which is connected to the diesel engine and is used to adjust the speed of the diesel engine.

[0022] In one embodiment of the present invention, a mechanical speed governor is further included, which is connected to the diesel engine and is used to adjust the speed of the diesel engine.

[0023] In one embodiment of the present invention, an output switch is further included, which is electrically connected between the generator and the power distribution system, and the output switch is an HVX-20 vacuum circuit breaker.

[0024] As described above, this utility model provides an emergency power supply system for nuclear power plants. Through multi-layered redundancy design and an autonomous power supply mechanism, it significantly improves the emergency reliability and continuous operation capability of the generator set. By setting a manual start valve, it ensures that the diesel engine can still be started mechanically in the event of power failure, guaranteeing a high success rate for black starts. The permanent magnet generator directly supplies power to the excitation system, eliminating the need for external power sources, enabling the generator to quickly establish voltage and output stable power, providing emergency power support to downstream loads. After power generation, the self-powered mode supplies power to the protection / control system and auxiliary equipment through the internal power distribution system, forming a closed-loop operation, reducing dependence on external power sources and supporting the long-term stable operation of the unit. The design of the mechanical governor and electronic governor ensures basic speed control during the initial startup phase, and switches to the electronic governor to precisely maintain the rated speed after power is restored, optimizing the power generation frequency and balancing emergency reliability and power generation quality. The overall solution, through mechanical redundancy, autonomous power supply, and intelligent switching mechanisms, achieves rapid response, stable output, and continuous operation capability under extreme conditions, meeting the stringent requirements of emergency power systems in high-safety scenarios such as nuclear power.

[0025] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of an emergency power supply system for a nuclear power plant in one embodiment of the present invention.

[0028] In the diagram: 10. Compressed air tank; 21. Main start valve; 22. Manual start valve; 23. Start solenoid valve; 31. Starter motor; 32. Diesel engine; 33. Generator; 41. Permanent magnet generator; 42. Excitation device; 43. Automatic excitation switch; 44. Manual excitation switch; 50. Electronic speed governor; 60. Mechanical speed governor; 71. Auxiliary equipment; 72. Power distribution system; 73. Downstream load; 74. Outlet switch. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0030] Please see Figure 1 This utility model provides an emergency power supply system for nuclear power plants. This system can be applied in nuclear power plants to provide power in the event of a loss of normal power supply, thereby maintaining the nuclear power plant in a safe state or mitigating the hazards of an accident. The emergency power supply system may include a compressed air tank 10, a starting valve assembly, a generator set, a permanent magnet generator 41, an excitation device 42, an electronic speed governor 50, a mechanical speed governor 60, and an outlet switch 74.

[0031] In some embodiments, the number of compressed air tanks 10 may be at least one. The compressed air tank 10 stores compressed air for driving the starter motor 31 in an emergency. When needed, the compressed air can be released through a piping system to drive the starter motor 31. The compressed air tank 10 may be equipped with a pressure sensor and regulating device to ensure that the compressed air pressure is within a safe range and to adjust it as needed.

[0032] In some embodiments, the generator set is the core component of the emergency power supply system. The generator set may include at least a starter motor 31, a diesel engine 32, and a generator 33. The starter motor 31 can be a pneumatic or electric device used to drive the flywheel of the diesel engine 32. Compressed air drives the gears of the starter motor 31 to rotate, thereby starting the diesel engine 32. The diesel engine 32 can be the power source of the generator set. After starting, the diesel engine 32 can drive the generator 33 to operate and generate electrical energy. The generator 33 can convert the mechanical energy of the diesel engine 32 into electrical energy. In emergency situations, it provides power to the nuclear power plant. The starter motor 31 may be model ST999BP03R31.

[0033] In some embodiments, the start valve assembly may be a key component connecting the compressed air tank 10 and the starter motor 31, used to control the flow of compressed air and the start-up process. The start valve assembly may include at least a main start valve 21, at least one manual start valve 22, and a start solenoid valve 23.

[0034] In some embodiments, the main start valve 21 can be connected to the main pipeline between the compressed air tank 10 and the starter motor 31. The main start valve 21 controls the release of compressed air, driving the gears of the starter motor 31 to rotate. After the main start valve 21 is opened, the compressed air can provide power to make the gears of the starter motor 31 rotate rapidly. The main start valve 21 can be an SRV150.

[0035] In some embodiments, the starter solenoid valve 23 can be connected to a secondary pipeline between the compressed air tank 10 and the starter motor 31. The starter solenoid valve 23 controls the release of compressed air, driving the gear of the starter motor 31 to engage with the flywheel of the diesel engine 32. During startup, the starter solenoid valve 23 ensures proper engagement between the gear of the starter motor 31 and the flywheel of the diesel engine 32, thereby starting the diesel engine 32. The starter solenoid valve 23 is electrically connected to the battery pack to ensure normal operation even during power outages. The model of the starter solenoid valve 23 can be 150BMP-2451B.

[0036] In some embodiments, when the battery pack loses its normal operating power, causing the starter solenoid valve 23 to fail to open, the manual starter valve 22 functions as a backup valve, manually driving the gear of the starter motor 31 to engage with the flywheel of the diesel engine 32. The manual starter valve 22 can be connected to a backup pipeline between the compressed air tank 10 and the starter motor 31. Each backup pipeline corresponds to one manual starter valve 22, ensuring redundancy and reliability. The manual starter valve model can be SMB-618.

[0037] In some embodiments, in the event of battery failure or the inability to open the solenoid valve 23, the diesel generator set can be started through the coordinated operation of the manual start valve 22 and the main start valve 21. First, the operator manually opens the manual start valve 22, and compressed air drives the gear of the starter motor 31 to engage with the flywheel of the diesel engine 32 via a backup pipe. Then, the operator opens the main start valve 21, and compressed air drives the gear of the starter motor 31 to rotate rapidly via the main pipe. The gear of the starter motor 31 drives the flywheel of the diesel engine 32 to rotate, starting the diesel engine 32. The diesel engine 32 then drives the generator 33 to operate, generating electrical energy. The generator 33 can provide emergency power to the nuclear power plant.

[0038] In some embodiments, the air inlets of the secondary pipeline and the backup pipeline can be connected, and both air inlets can be connected to the main start valve 21. By opening the main start valve 21, compressed air in the compressed air tank can enter the secondary pipeline and the backup pipeline respectively.

[0039] In some embodiments, the air inlet of the secondary pipeline can be connected to the compressed air tank 10. The air inlet of the standby pipeline is connected to the compressed air tank 10. At this time, the compressed air in the compressed air tank can directly enter the secondary pipeline and the standby pipeline.

[0040] In some embodiments, the excitation module can be used to provide an excitation power supply for the generator 33, so as to ensure that the generator 33 can generate electricity normally and provide a power supply to the outside. The excitation module can include a permanent magnet machine 41, an excitation device 42, an automatic excitation switch 43, and at least one manual excitation switch 44.

[0041] In some embodiments, the permanent magnet machine 41 can be coaxially connected to the rotating end of the generator 33 and is used to generate an alternating current power supply. After the diesel engine 32 starts successfully, the permanent magnet machine 41 generates alternating current as the generator 33 rotates and transmits it to the excitation device 42.

[0042] In some embodiments, the excitation device 42 can be electrically connected between the permanent magnet machine 41 and the generator 33 and is used to convert the alternating current power supply generated by the permanent magnet machine 41 into an excitation power supply. The excitation device 42 can transmit the converted excitation power supply to the generator 33, enabling the generator 33 to generate a stable terminal voltage.

[0043] In some embodiments, the automatic excitation switch 43 can be electrically connected between the excitation device 42 and the generator 33 and is used to automatically control the operation of the excitation system. Under normal circumstances, the automatic excitation switch 43 can automatically complete the operation of the excitation system without manual intervention.

[0044] In some embodiments, the manual excitation switch 44 can be electrically connected between the excitation device 42 and the generator 33 and is used to manually control the operation of the excitation system. When the automatic excitation switch 43 fails or the battery pack fails to provide power to the automatic excitation switch 43, it is necessary to manually operate the manual excitation switch 44 to realize the operation of the excitation system by operating the manual excitation switch 44.

[0045] In some embodiments, the manual excitation switch 44 can include a contactor and an auxiliary contact module. The model of the contactor is ABB AL16-30-10, and the model of the auxiliary contact module is CA5-10 / CA5-1. Among them, the contactor can be used to control the on and off of the excitation power supply. By operating the contactor, the circuit between the excitation device 42 and the generator 33 can be manually connected or disconnected, thereby realizing the operation or stop of the excitation system. The auxiliary contact module can be a supporting component of the contactor and is used to provide additional control signals or status feedback. The auxiliary contact module can be used to monitor the status of the contactor (such as on or off), or transmit the status signal to other control systems.

[0046] In some embodiments, after the diesel engine 32 starts successfully, it drives the generator 33 and the permanent magnet generator 41 to rotate coaxially. The permanent magnet generator 41 generates alternating current as the generator 33 rotates and supplies it to the excitation device 42. The excitation device 42 converts the alternating current supplied by the permanent magnet generator 41 into excitation power and supplies it to the generator 33. Under normal circumstances, the automatic excitation switch 43 automatically activates the excitation system. In the event of a failure of the automatic excitation switch 43 or a battery failure, the operator activates the excitation system via the manual excitation switch 44. The generator 33 generates a stable terminal voltage based on the excitation power. The generator 33 provides power to the downstream load 73 through the output switch 74. The output switch 74 can be an HVX-20 vacuum circuit breaker.

[0047] In some embodiments, the mechanical governor 60 can be connected to the diesel engine 32 to adjust the speed of the diesel engine 32. The mechanical governor 60 can be a speed control device based on mechanical principles, operating without an external power source. In the event of battery failure, the mechanical governor 60 can serve as a backup speed control device to control and maintain the operation of the diesel engine 32. After the diesel engine 32 starts, the mechanical governor 60 is responsible for initially adjusting the speed of the diesel engine 32 to ensure its stable operation. The mechanical governor 60 can be model 2231-1GL-15.

[0048] In some embodiments, the electronic governor 50 can be connected to the diesel engine 32 to adjust the speed of the diesel engine 32. The electronic governor 50 can be an electronically controlled speed control device capable of precisely controlling the speed of the diesel engine 32. The electronic governor 50 requires an external power source (such as a battery pack) to operate normally. When the battery is available, the electronic governor 50 can receive control signals to precisely adjust the speed of the diesel engine 32, maintaining it at its rated speed. After the generator 33 starts and supplies power, the electronic governor 50 becomes available due to the restored power supply and can take over the speed control of the diesel engine 32. The electronic governor 50 can be a VIKING 35 model.

[0049] In some embodiments, in the event of battery failure, the electronic governor 50 cannot be powered. After the diesel engine 32 is started, the mechanical governor 60 controls and maintains the operation of the diesel engine 32. The diesel engine 32 starts successfully, driving the generator 33. The generator 33 supplies power to restore power to the electronic governor 50. Subsequently, the electronic governor 50 becomes available due to the restored power supply and takes over the speed control of the diesel engine 32. The electronic governor 50 can precisely adjust the speed of the diesel engine 32 to maintain it at its rated speed.

[0050] In some embodiments, auxiliary equipment 71 refers to key equipment that maintains the long-term continuous operation of the generator set. Auxiliary equipment 71 may include a protection / control system and diesel engine auxiliary equipment. The protection / control system can be used to monitor and control the operating status of the generator set to ensure its safe and stable operation. Diesel engine auxiliary equipment may include cooling systems, lubrication systems, fuel systems, etc., to maintain the normal operation of the diesel engine 32. The power distribution system 72 provides power to the auxiliary equipment 71, ensuring that the auxiliary equipment 71 can work normally, thereby maintaining the long-term continuous operation of the generator set. At the same time, the power distribution system 72 can also provide power to downstream loads 73. Downstream loads 73 refer to the end users of the nuclear power plant's emergency power supply system. Downstream loads 73 may include reactor cooling pumps, control room equipment, lighting systems, communication systems, etc. The power distribution system 72 can distribute the power provided by the generator 33 to the downstream loads 73 to ensure that these devices can work normally in emergency situations.

[0051] As can be seen, the above scheme significantly improves the emergency reliability and continuous operation capability of the generator set through multi-layered redundancy design and autonomous power supply mechanism. By setting a manual start valve, the diesel engine can still be started mechanically in the event of power failure, ensuring a high success rate for black starts. The permanent magnet generator directly supplies power to the excitation system, eliminating reliance on external power sources, enabling the generator to quickly establish voltage and output stable power, providing emergency power support to downstream loads. The self-powered mode after power generation supplies power to the protection / control system and auxiliary equipment through the internal power distribution system, forming a closed-loop operation, reducing dependence on external power sources and supporting long-term stable operation of the unit. The design of the mechanical and electronic speed governors ensures basic speed control during the initial startup phase, switching to the electronic speed governor to precisely maintain the rated speed after power is restored, optimizing the power generation frequency, and balancing emergency reliability and power generation quality. The overall scheme, through mechanical redundancy, autonomous power supply, and intelligent switching mechanisms, achieves rapid response, stable output, and continuous operation under extreme conditions, meeting the stringent requirements of emergency power systems in high-safety scenarios such as nuclear power.

[0052] The embodiments of this utility model disclosed above are merely illustrative of the present utility model. The embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Obviously, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. An emergency power supply system for a nuclear power plant, characterized in that, include: Compressed air tank, used to supply compressed air; A generator set includes a starter motor, a diesel engine, and a generator connected in sequence. The diesel engine is used to drive the generator and provide power to the outside world. A starter valve assembly is connected to the pipeline between the compressed air tank and the starter motor, and the starter valve assembly includes: The main start valve is connected to the main pipeline between the compressed air tank and the starter motor, and is used to drive the gear of the starter motor to rotate by compressed air; A solenoid valve is connected to a secondary pipeline between the compressed air tank and the starter motor, and is used to drive the gear of the starter motor to mesh with the flywheel of the diesel engine via compressed air; the solenoid valve is electrically connected to the battery pack. At least one manual start valve is connected to a spare pipe between the compressed air tank and the starter motor, for using compressed air to drive the gear of the starter motor to mesh with the flywheel of the diesel engine; each spare pipe corresponds to one manual start valve.

2. The emergency power supply system for a nuclear power plant according to claim 1, characterized in that, The secondary pipeline is connected to the air inlet of the backup pipeline and to the main start valve.

3. The emergency power supply system for a nuclear power plant according to claim 1, characterized in that, The secondary pipeline is connected to the compressed air tank, and the backup pipeline is connected to the compressed air tank.

4. The emergency power supply system for a nuclear power plant according to claim 1, characterized in that, It also includes an excitation module, which comprises: A permanent magnet motor, connected to the rotating end of the generator, is used to provide AC power. An excitation device is electrically connected between the permanent magnet generator and the generator. It is used to convert the AC power supply into an excitation power supply and to deliver the excitation power supply to the generator. The generator provides power to the outside world based on the excitation power supply.

5. The emergency power supply system for a nuclear power plant according to claim 4, characterized in that, The excitation module also includes an automatic excitation switch, which is electrically connected between the excitation device and the generator.

6. The emergency power supply system for a nuclear power plant according to claim 5, characterized in that, The excitation module also includes at least one manual excitation switch, which is electrically connected between the excitation device and the generator.

7. The emergency power supply system for a nuclear power plant according to claim 6, characterized in that, The manual trip switch includes a contactor and an auxiliary contact module. The contactor is model ABB AL16-30-10, and the auxiliary contact module is model CA5-10 / CA5-1.

8. The emergency power supply system for a nuclear power plant according to claim 1, characterized in that, It also includes an electronic governor, which is connected to the diesel engine and used to adjust the speed of the diesel engine.

9. The emergency power supply system for a nuclear power plant according to claim 1, characterized in that, It also includes a mechanical governor, which is connected to the diesel engine and used to adjust the speed of the diesel engine.

10. The emergency power supply system for a nuclear power plant according to claim 1, characterized in that, It also includes an outlet switch, which is electrically connected between the generator and the power distribution system, and the outlet switch is an HVX-20 vacuum circuit breaker.

Images