Emergency power supply system for nuclear power plant
Patent Information
- Application Number
- PCT/CN2025/110194
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-25
- Filing Date
- 2025-07-23
- Publication Date
- 2026-09-03
Smart Images
Figure CN2025110194_03092026_PF_FP_ABST
Abstract
Description
Nuclear power plant emergency power system Technical Field
[0001] This application relates to the field of nuclear power technology, and in particular to an emergency power supply system for nuclear power plants. Background Technology
[0002] Emergency diesel generator sets are used in nuclear power plants as the last line of defense for electrical safety. When a nuclear power plant loses its mains power and external grid backup power, the emergency diesel generator sets automatically start to provide emergency power to the plant's safety facilities. Currently, a single reactor in a nuclear power plant is typically equipped with three high-power emergency diesel generators, each with a rated power of approximately 8000 kW. These three high-power emergency diesel generators are located in three separate buildings. These high-power emergency diesel generators are usually based on the most powerful diesel generators currently available on the market, and are developed through design optimization and upgrades. However, they have the following drawbacks: they are close to the upper limit of the design benchmark, resulting in certain shortcomings; the generator structure is complex, especially the external auxiliary support system, which limits online maintenance, and some models require return to the factory for repair; the design and manufacturing are difficult, and the market application is small, resulting in slow technological upgrades and poor reliability; the existing models used are numerous and inconsistent, and the technology, experience, spare parts, and tools are not interchangeable; the selection of the basic generator model for retrofitting and upgrading is limited, and currently only one type of diesel engine is suitable for the existing nuclear power line requirements. Summary of the Invention
[0003] The technical problem to be solved by this application is to provide an improved emergency power supply system for nuclear power plants, addressing at least one of the deficiencies mentioned in the background art.
[0004] The technical solution adopted by this application to solve its technical problem is as follows: A nuclear power plant emergency power supply system is provided, which includes an emergency diesel generator set, an external auxiliary system, and multiple built-in auxiliary systems; the emergency diesel generator set includes multiple small-power diesel generators, each of which has a maximum power of no more than 2400KW; the built-in auxiliary systems correspond one-to-one with the small-power diesel generators, and each built-in auxiliary system is integrated into the corresponding small-power diesel generator; the external auxiliary system includes a fuel system and an exhaust system, and each of the small-power diesel generators is connected to the fuel system and the exhaust system respectively.
[0005] In some embodiments, the built-in auxiliary system includes a high-temperature water system, a low-temperature water system, a compressed air system, an air intake system, and a lubricating oil system.
[0006] In some embodiments, the fuel system includes a main fuel storage tank, a fuel supply header, multiple fuel supply branch pipes, and multiple day fuel tanks;
[0007] The main oil storage tank is connected to the main oil supply pipe, and multiple oil supply branch pipes are respectively connected to the main oil supply pipe. The daily oil tank is connected between the oil supply branch pipes and the small-power diesel generator.
[0008] In some embodiments, the oil supply branch pipe is equipped with a control valve, which controls its opening and closing based on the liquid level information of the daily oil tank.
[0009] In some embodiments, the fuel system further includes a bypass line connected between the fuel supply main pipe and the day fuel tank, and is arranged in parallel with the fuel supply branch pipe.
[0010] In some embodiments, the nuclear power plant emergency power system further includes an electrical primary control system, which includes a parallel bus, the output terminals of each of the small-power diesel generators are respectively connected to the parallel bus, and the parallel bus is connected to the nuclear power plant's emergency power bus.
[0011] In some embodiments, the nuclear power plant emergency power system further includes an electrical secondary control system, which includes a parallel control cabinet and multiple controllers. Each controller is connected to a small-power diesel generator in a one-to-one correspondence, and each controller is connected to the parallel control cabinet.
[0012] In some embodiments, the nuclear power plant emergency power system further includes an electrical secondary control system, which includes a first instrument control cabinet. The first instrument control cabinet is connected to the external auxiliary system and the internal auxiliary system respectively, and is used to control the operation of the external auxiliary system and the internal auxiliary system.
[0013] In some embodiments, the nuclear power plant emergency power system further includes an electrical secondary control system, which includes a second instrument control cabinet. The second instrument control cabinet is connected to the external auxiliary system and the built-in auxiliary system respectively, and is used to display the parameter information and alarm information of the external auxiliary system and the built-in auxiliary system.
[0014] In some embodiments, the nuclear power plant emergency power system further includes a battery bank, which and the emergency diesel generator set are respectively installed in different rooms within the nuclear power plant building. The battery bank is connected to each of the small-power diesel generators to provide power to the starter motors of each of the small-power diesel generators.
[0015] In some embodiments, the nuclear power plant emergency power supply system further includes a 24V conversion cabinet and a 24V switch cabinet, which are connected by cables to provide 24V control power to each load device.
[0016] In some embodiments, the nuclear power plant emergency power system further includes an electrical secondary control system and a fault recorder. The electrical secondary control system includes at least one of a parallel control cabinet, a controller, a first instrument control cabinet, and a second instrument control cabinet. Multiple controllers are connected one-to-one with the small-power diesel generator, and each controller is connected to the parallel control cabinet. The first instrument control cabinet is connected to both the external auxiliary system and the internal auxiliary system, and is used to control the operation of the external auxiliary system and the internal auxiliary system. The second instrument control cabinet is connected to both the external auxiliary system and the internal auxiliary system, and is used to display the parameter information and alarm information of the external auxiliary system and the internal auxiliary system. The fault recorder is connected to at least one of the parallel control cabinet, the controller, the first instrument control cabinet, and the second instrument control cabinet, and is used to record fault waveforms of electrical parameters.
[0017] In some embodiments, all of the small-power diesel generators are located in the same room within the nuclear power plant building; and / or, the external auxiliary systems are integrated with the auxiliary and support systems of the nuclear power plant.
[0018] In some embodiments, the sum of the rated power of each of the small-power diesel generators is greater than the rated power required by the nuclear power plant's emergency power system.
[0019] In some embodiments, the plurality of low-power diesel generators include a plurality of primary diesel engines and at least one backup diesel engine, wherein the sum of the rated power of each of the primary diesel engines is greater than or equal to the rated power required by the nuclear power plant emergency power system, and the sum of the rated power of each of the primary diesel engines and the backup diesel engine is greater than the rated power required by the nuclear power plant emergency power system.
[0020] In some embodiments, the rated power of the primary diesel engine and the rated power of the standby diesel engine are equal.
[0021] This application has at least the following beneficial effects: It replaces the high-power emergency diesel generators currently used in the nuclear power field with multiple small-power diesel generators, each with a maximum power not exceeding 2400KW. Since the maximum power of these small-power diesel generators does not exceed 2400KW, their auxiliary systems are relatively small, allowing some auxiliary systems to be integrated internally as built-in auxiliary systems. Furthermore, these small-power diesel generators have a simple structure and a large market presence, resulting in rapid technological improvements, upgrades, and iterations, thus ensuring high reliability. Within the power range of no more than 2400KW, there are many models to choose from, and related technologies, experience, spare parts, and tools are relatively common, facilitating maintenance. Attached Figure Description
[0022] To more clearly illustrate the technical solution of this application, the following will further describe this application in conjunction with the accompanying drawings and embodiments. In the accompanying drawings:
[0023] Figure 1 is a schematic diagram of the fuel system of a nuclear power plant emergency power system according to some embodiments of this application;
[0024] Figure 2 is a schematic diagram of the electrical primary control system of a nuclear power plant emergency power supply system according to some embodiments of this application;
[0025] Figure 3 is a schematic diagram of the electrical secondary control system of the nuclear power plant emergency power system according to some embodiments of this application. Detailed Implementation
[0026] To provide a clearer understanding of the technical features, objectives, and effects of this application, the specific embodiments of this application will now be described in detail with reference to the accompanying drawings.
[0027] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, that component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.
[0028] One embodiment of this application describes a nuclear power plant emergency power system comprising an emergency diesel generator set, multiple built-in auxiliary systems, and an external auxiliary system. The emergency diesel generator set includes multiple small-power diesel generators 40, each with a maximum power not exceeding 2400 kW. Specifically, the multiple small-power diesel generators 40 may refer to at least two small-power diesel generators 40. The number of small-power diesel generators 40 can be determined based on the power of the selected small-power diesel generators 40 and the rated power required by the emergency power system of the applied nuclear power plant; this application does not impose excessive limitations on this. The term "small-power" in "small-power diesel generator 40" primarily refers to its power relative to the high-power emergency diesel generators currently used in the nuclear power field. The rated power of each small-power diesel generator 40 can be the same or different. For example, for a nuclear power plant requiring a rated power of 8400 kW for its emergency power system, four small-power diesel generators 40 with a rated power of 2200 kW can be configured to replace the original high-power diesel generator with a rated power of 8400 kW. The small-power diesel generator 40 with a maximum power of no more than 2400KW can cover almost all technically mature diesel generators on the market that can integrate auxiliary systems into the main unit, that is, have built-in auxiliary systems.
[0029] Each built-in auxiliary system corresponds one-to-one with a small-power diesel generator 40, with each built-in auxiliary system integrated into its corresponding small-power diesel generator 40. This built-in auxiliary system is primarily used to provide the diesel generator with working media such as water, air, and lubricating oil.
[0030] The external auxiliary system includes a fuel system and an exhaust system, with each small-power diesel generator 40 connected to both the fuel system and the exhaust system. This external auxiliary system primarily provides fuel and exhaust pathways for the diesel generators.
[0031] In other words, the external auxiliary system and the small-power diesel generator 40 are independent of each other. The external auxiliary system is independently located on the outside of the small-power diesel generator 40, while the internal auxiliary system is integrated into the small-power diesel generator 40. However, the high-power emergency diesel generators currently used in the nuclear power field have undergone modifications and upgrades, resulting in complex and large external auxiliary systems that cannot be integrated into the diesel engine.
[0032] In summary, this application uses multiple small-power diesel generators 40 with a maximum power not exceeding 2400KW to replace the high-power emergency diesel generators currently used in the nuclear power field. Since the maximum power of these small-power diesel generators 40 does not exceed 2400KW, their auxiliary systems are relatively small, allowing some auxiliary systems to be integrated within them as built-in auxiliary systems. Furthermore, these small-power diesel generators 40 have a simple structure, a large market presence, and therefore rapid technological improvement, upgrading, and iteration, resulting in high reliability. Within the power range of no more than 2400KW, there are many models to choose from, and related technologies, experience, spare parts, and tools are relatively common, facilitating maintenance.
[0033] As described in the background section, the three high-power emergency diesel generators currently installed in nuclear power plants are located in three separate buildings due to their large size. These buildings also house supporting systems such as civil engineering structures, ventilation and fire protection systems, communication instruments, and control cabinet cables. Each high-power emergency diesel generator itself is equipped with seven auxiliary systems: an external fuel system, a compressed air system, a lubrication system, a high-temperature water system, a low-temperature water system, an intake system, and an exhaust system. These systems include numerous large and complex pieces of equipment such as storage tanks, heat exchangers, pumps, heaters, air compressors, and radiators, along with their associated valves and piping accessories. All these auxiliary systems are located outside the plant buildings, making them large and complex, inconvenient for operation and maintenance, and costly.
[0034] Compared with existing technologies, this application uses multiple small-power diesel generators 40 with a maximum power not exceeding 2400KW to replace the high-power emergency diesel generators currently used in the nuclear power field. These multiple small-power diesel generators 40 can be centrally arranged in one building and one room. That is, all the small-power diesel generators 40 are located in the same room within the nuclear power plant building. Furthermore, the external auxiliary systems and the nuclear power plant's auxiliary and support systems can be integrated into a single layout design, maximizing the simplification of the nuclear power plant's emergency power system layout. The nuclear power plant's auxiliary and support systems include water supply systems, ventilation and air conditioning (HVAC) systems, and electrical systems. Simultaneously, the building's floor height is reduced from the original 7 floors required for high-power diesel generators to 2 floors. The building only needs to accommodate a diesel generator hall, oil leak tank room, fire-fighting foam room, gas cylinder room, oil tank room, air conditioning room, and electrical room, reducing the number of rooms required by the original high-power diesel generator building layout by more than 50%, significantly reducing the space required for diesel generator placement. In some embodiments, the sum of the rated power of the individual small-power diesel generators 40 exceeds the rated power required by the nuclear power plant's emergency power system. The rated power required by the nuclear power plant's emergency power system varies depending on the design and scale of the nuclear power plant. For example, for a nuclear power plant requiring a rated power of 8400 kW for its emergency power system, four small-power diesel generators 40 with a rated power of 2200 kW each can be configured, resulting in a sum of 8800 kW, which exceeds the rated power required by the emergency power system. This allows for redundant power supply configuration of the nuclear power plant's emergency power system, improving the reliability of the emergency power supply.
[0035] Furthermore, in some embodiments, the plurality of small-power diesel generators 40 include a plurality of main diesel engines and at least one standby diesel engine. The sum of the rated power of each main diesel engine is greater than or equal to the rated power required by the nuclear power plant's emergency power system. The sum of the rated power of each main diesel engine and the standby diesel engine is greater than the rated power required by the nuclear power plant's emergency power system. For example, for a nuclear power plant requiring a rated power of 8400kW for the emergency power system, five small-power diesel generators 40 can be configured, each with a rated power of 2200kW. Four of these small-power diesel generators 40 serve as main diesel engines, with a sum of rated power of 8800kW, slightly greater than the rated power required by the emergency power system. The remaining small-power diesel generator 40 serves as a standby diesel engine. Thus, when one of the main diesel engines fails for maintenance, the standby diesel engine can be activated without affecting the normal operation of the diesel generator set. Furthermore, having the same rated power for both the primary and standby diesel engines allows for greater flexibility in load distribution; the same spare parts and maintenance standards can be used, reducing spare parts inventory costs and management complexity; and operators only need to be familiar with equipment of one power rating, reducing training costs and the risk of operational errors. Of course, in some other embodiments, the rated power for the primary and standby diesel engines may not be equal.
[0036] In summary, this application replaces the high-power emergency diesel generators currently used in the nuclear power field with N small-power main diesel engines (maximum power not exceeding 2400KW) and X small-power standby diesel engines (maximum power not exceeding 2400KW). The configuration concept for the main diesel engines is: the total power load required by the nuclear power plant is evenly distributed among the N small-power main diesel engines. Typically, the N small-power main diesel engines are diesel generators of the same model and power. The total output power of these main diesel engines should be greater than and as close as possible to the original high-power diesel engine. The value of N should not be too large, meaning the minimum rated power of each small-power main diesel engine should not be too small. The configuration concept for X is: redundancy configuration based on the power, model, and functional requirements of each small-power main diesel engine. Typically, the main diesel engine and the standby diesel engine can be of the same model. The number of X small-power standby diesel engines can be appropriately increased or decreased according to the user's safety and maintenance needs. The redundant configuration of X small-power standby diesel engines enables flexible maintenance of the diesel generator set.
[0037] In some embodiments, the built-in auxiliary system includes a high-temperature water system, a low-temperature water system, a compressed air system, an intake system, and a lubricating oil system. The high-temperature water system is mainly used to cool heat-generating components, improve fuel combustion efficiency, preheat the diesel engine, and heat the lubricating oil. The low-temperature water system is mainly used to cool engine oil, cool boosted air, and maintain a suitable intake air temperature. The compressed air system is mainly used to start the diesel engine and drive pneumatic tools (such as pneumatic wrenches and jackhammers). The intake system is mainly used to guide air in, filter air impurities, boost power, cool boosted air, and control the intake process. The lubricating oil system is mainly used to provide flowing lubricating oil to the inside of the diesel engine, serving functions such as lubricating parts to reduce friction, cooling, keeping parts clean, sealing moving parts, preventing rust and corrosion, and absorbing vibrations.
[0038] Because this application uses multiple small-power diesel generators 40 with a maximum power not exceeding 2400KW to replace the high-power emergency diesel generators currently used in the nuclear power field, the external auxiliary systems are reduced to only the fuel system and exhaust system. The remaining auxiliary systems—high-temperature water system, low-temperature water system, compressed air system, intake system, and lubrication system—are all integrated into the small-power diesel generator 40 itself as built-in auxiliary systems. As a result, taking four 2200kW main diesel engines and one 2200kW standby diesel engine as an example, the number of auxiliary system devices in the nuclear power plant's emergency power system is reduced from 44 to 14, and the number of power supply devices required for the auxiliary system is reduced from 30 to 2. This significantly reduces the number of diesel engine auxiliary system devices and greatly lowers equipment operation and maintenance costs.
[0039] As shown in Figure 1, in some embodiments, the fuel system mainly includes a main fuel storage tank 10, a main fuel supply pipe 20, multiple fuel supply branch pipes 21, and multiple day-use fuel tanks 11. The main fuel storage tank 10 is connected to the main fuel supply pipe 20, the multiple fuel supply branch pipes 21 are respectively connected to the main fuel supply pipe 20, and the day-use fuel tanks 11 are connected between the fuel supply branch pipes 21 and the small-power diesel generators 40. Specifically, in the embodiment shown in Figure 1, each small-power diesel generator 40 is assigned one day-use fuel tank 11, and each day-use fuel tank 11 is assigned one fuel supply branch pipe 21. That is, the number of fuel supply branch pipes 21, the number of day-use fuel tanks 11, and the number of small-power diesel generators 40 are the same. Of course, in other embodiments, the number of fuel supply branch pipes 21, the number of day-use fuel tanks 11, and the number of small-power diesel generators 40 may also be different. The main fuel storage tank 10, the main fuel supply pipe 20, the fuel supply branch pipes 21, the day-use fuel tanks 11, and the small-power diesel generators 40 are connected sequentially. Both the main fuel storage tank 10 and the day-use fuel tank 11 are primarily used for storing fuel oil. Fuel oil supplied from the main fuel storage tank 10 flows from the fuel supply header 20 to each fuel supply branch pipe 21, and then to the day-use fuel tank 11 for storage. The fuel required for the operation of the small-power diesel generator 40 is supplied by the day-use fuel tank 11. In this way, at least one main fuel storage tank 10 and one fuel supply header 20 can simultaneously supply fuel to multiple small-power diesel generators 40, simplifying the fuel system.
[0040] As shown in the embodiment of Figure 1, the fuel system also includes at least one fuel supply pump 30, which is installed on the fuel supply header 20 and is mainly used to provide power for fuel to flow from the fuel supply header 20 to the daily fuel tank 11.
[0041] Further, as shown in Figure 1, in some embodiments, a control valve 31 is provided on the fuel supply branch pipe 21. Specifically, the control valve 31 refers to a valve that can be used for automated control, such as a solenoid valve, a pneumatic actuator, a hydraulic valve, etc. The control valve 31 controls its opening and closing based on the liquid level information of the daily fuel tank 11. That is, the control valve 31 controls the connection and isolation between the fuel supply branch pipe 21 and the daily fuel tank 11 based on the liquid level information of the daily fuel tank 11. For example, a liquid level sensor (not shown) can be installed on the daily fuel tank 11, and the liquid level sensor is communicatively connected to the control valve 31. The liquid level sensor monitors the liquid level information of the fuel inside the daily fuel tank 11 in real time. When the liquid level information received by the liquid level sensor is less than a first preset threshold, the control valve 31 opens, the fuel supply branch pipe 21 and the daily fuel tank 11 remain connected, and fuel can be input into the daily fuel tank 11 from the fuel supply branch pipe 21. Conversely, when the liquid level information received by the liquid level sensor exceeds the second preset threshold, the control valve 31 closes, isolating the fuel supply branch pipe 21 and the daily fuel tank 11. Fuel cannot enter the daily fuel tank 11 from the fuel supply branch pipe 21, thus stopping the fuel supply to the daily fuel tank 11. In this way, the fuel intake of the daily fuel tank 11 can be automatically controlled, ensuring that only one fuel supply module is needed to simultaneously supply fuel to multiple small-power diesel generators 40 through at least one main fuel storage tank 10 and one fuel supply header 20, and to accurately control the liquid level height of the daily fuel tank 11. This avoids the need for multiple independent fuel systems and simplifies the fuel system.
[0042] Furthermore, as shown in Figure 1, in some embodiments, the fuel system also includes a bypass line 22, which is connected between the fuel supply main line 20 and the day fuel tank 11, and is arranged in parallel with the fuel supply branch line 21. If the control valve 31 malfunctions and needs maintenance, the system can switch to the bypass line 22 to continue supplying fuel to the day fuel tank 11, thereby not affecting the safe operation of the diesel engine.
[0043] As shown in Figure 2, in some embodiments, the nuclear power plant's emergency power system also includes an electrical primary control system. This primary control system includes a parallel bus 50, with the output terminals of each small-power diesel generator 40 connected to the parallel bus 50. The parallel bus 50 is connected to the nuclear power plant's emergency power bus 51. That is, the parallel bus 50 connects the nuclear power plant's emergency power bus 51 and each small-power diesel generator 40, serving as an intermediate bridge for power transmission. The nuclear power plant's emergency power bus 51, also known as the LHA / B bus, connects to the nuclear power plant's dedicated safety facilities, providing emergency power to these facilities. These safety facilities include the Safety Injection System (RIS), the Emergency Evacuation System (EAS), the Auxiliary Feedwater System (ASG), the Enclosure Isolation System (EIE), and the Emergency Lighting System (ELS). The parallel bus 50 is used to complete the power collection at the emergency diesel generator set side and then send the power to the emergency power bus 51 of the nuclear power plant. The emergency power bus 51 then transmits the power to the dedicated safety facilities of the nuclear power plant. This simplifies the power output control of multiple small-power diesel generators 40.
[0044] Specifically, in the embodiment shown in Figure 2, the primary electrical control system further includes a first output line 52, a second output line 53, and several controllers 61. Each small-power diesel generator 40 is connected to the parallel bus 50 via a first output line 52, which is equipped with a circuit breaker 54. The parallel bus 50 and the emergency power bus 51 are connected via a second output line 53, which is also equipped with a circuit breaker 54. The parallel bus 50 is also connected to a voltage transformer cabinet (PT cabinet) 55, a fixed test load 56, a mobile power supply 57, and a plant power supply 58.
[0045] As shown in Figure 3, in some embodiments, the nuclear power plant emergency power system also includes an electrical secondary control system, which includes at least one parallel control cabinet 60 and multiple controllers 61. Each controller 61 is connected to a small-power diesel generator 40 in a one-to-one correspondence. That is, the number of controllers 61 can be the same as the number of small-power diesel generators 40, with one controller 61 assigned to each small-power diesel generator 40. Each controller 61 is connected to the parallel control cabinet 60. The parallel control cabinet 60 is mainly used to coordinate and control the operation of the entire system, realizing the system's logical control, including unit activation and deactivation, priority setting, etc. Each controller 61 is used to implement the start-up, shutdown, excitation, speed regulation, parallel operation, and protection control functions of the corresponding small-power diesel generator 40. In other words, this electrical secondary control system adopts a "main control + sub-control" architecture, collecting and centrally controlling information from multiple small-power diesel generators 40, and reducing the interfaces with the nuclear power plant's centralized control system.
[0046] As shown in Figure 3, in some embodiments, the electrical secondary control system further includes a first instrument control cabinet 62 and a second instrument control cabinet 63. The first instrument control cabinet 62 is connected to both the external auxiliary system and the internal auxiliary system, and is used to control their operation. Specifically, the first instrument control cabinet 62 controls the operation of the fuel system, exhaust system, high-temperature water system, low-temperature water system, compressed air system, intake system, and lubricating oil system. The second instrument control cabinet 63 is connected to both the external auxiliary system and the internal auxiliary system, and is used to display the parameter information and alarm information of the external and internal auxiliary systems. Specifically, the second instrument control cabinet 63 may be equipped with a display screen, control panel, and other human-machine interface, through which the parameter information and alarm information of the external and internal auxiliary systems are displayed. Of course, in other embodiments, only one instrument control cabinet may be used to control the operation of the external and internal auxiliary systems and display relevant information.
[0047] Specifically, the parallel control cabinet 60, the first instrument control cabinet 62, and the second instrument control cabinet 63 can be non-safety grade control cabinets or PLC control cabinets (programmable control cabinets) to reduce costs. Meanwhile, in some embodiments, the control equipment can be configured in the following three ways to further ensure and optimize the electrical secondary control system:
[0048] Firstly, in some embodiments, the nuclear power plant emergency power system may also include a battery bank (not shown), which is connected to various small-power diesel generators 40 of the diesel generator set to provide power to the starter motors of each small-power diesel generator 40, ensuring that the diesel engines can start quickly. The battery bank is placed in a dedicated room within the nuclear power plant building, that is, the battery bank and the emergency diesel generator set are respectively located in different rooms within the nuclear power plant building, in order to achieve high-temperature protection for the battery bank and facilitate the operation and maintenance of the diesel generator set itself, further ensuring and optimizing the electrical secondary control system.
[0049] Secondly, in some embodiments, the nuclear power plant emergency power supply system may also include a 24V conversion cabinet (not shown) and a 24V switch cabinet (not shown). The 24V conversion cabinet and the 24V switch cabinet are connected by cables and work together to provide 24V control power to various load devices. Specifically, a 24V conversion cabinet is an electrical device used to convert input power to 24V DC power. A 24V switch cabinet is an electrical device used in low-voltage power distribution systems, mainly for controlling and distributing 24V DC power. Specifically, the 24V conversion cabinet is mainly used to convert input power (such as AC 220V or higher voltage DC power) to a stable 24V DC power; the 24V conversion cabinet may include power modules, rectifiers, filters, and voltage regulators to ensure the stability and reliability of the output voltage. The 24V switch cabinet is mainly used to distribute 24V DC power to various load devices and provides overload, short-circuit protection, and switching control functions. The 24V switch cabinet may include multiple branch circuits for connecting sensors, controllers, actuators, and other devices. The 24V conversion cabinet and 24V switch cabinet can be connected to the primary electrical control system and the secondary electrical control system, respectively. The load equipment may include a parallel control cabinet 60, a first instrument control cabinet 62, a second instrument control cabinet 63, a controller 61, etc.
[0050] Third, in some embodiments, the nuclear power plant emergency power system may also include a fault recorder (not shown). The fault recorder is also called a fault recording cabinet. This fault recorder is connected to at least one of the controller 61, the parallel control cabinet 60, the first instrument control cabinet 62, and the second instrument control cabinet 63 to record fault waveforms for important electrical parameters.
[0051] In summary, this application has at least the following beneficial effects:
[0052] (1) N small-power main diesel engines with a maximum power of no more than 2400KW and X small-power standby diesel engines with a maximum power of no more than 2400KW are used to replace the high-power emergency diesel generators currently used in the nuclear power field; the redundant configuration of X small-power standby diesel engines can meet the needs of daily maintenance, so that the operation of the nuclear power plant is not restricted by the time limit for diesel engine return to the factory for maintenance, which greatly improves the flexibility and economy of equipment maintenance and well meets the needs of users; at the same time, the design scheme of multiple small-power main diesel engines + small-power standby diesel engines greatly simplifies the configuration of auxiliary systems, significantly reduces the equipment required for auxiliary systems, reduces operation and maintenance costs, and reduces the space required for plant layout, simplifying the grid connection control process;
[0053] Meanwhile, the small-power diesel generator 40 has high reliability, a large market share, and rapid technological improvement and iteration. Moreover, within the power requirements of existing nuclear power plants, the small-power diesel generator 40 offers a variety of power versions, a large design margin, and unrestricted equipment supply channels. It effectively solves many problems existing in nuclear power plants, such as the limited power versions of large diesel engines, proximity to the upper limit of design benchmarks, complex models, complicated auxiliary support systems leading to limited online maintenance (some models require return to the factory for maintenance), high design and manufacturing difficulty, small market application, slow technological upgrades and iterations, many and inconsistent application models, and non-universal technology, experience, spare parts and tools, as well as limited selection.
[0054] (2) The innovative fuel system can simultaneously supply fuel to multiple small-power diesel generators 40 through at least one main fuel tank 10 and one fuel supply header 20, which simplifies the fuel system.
[0055] (3) The innovative primary and secondary electrical control systems improve the success rate and reliability of system startup and grid connection. It is understood that the above embodiments only illustrate preferred implementations of this application, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of this application's patent. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of this application, and can also make several modifications and improvements, all of which fall within the protection scope of this application. Therefore, any equivalent transformations and modifications made within the scope of the claims of this application should be covered by the claims of this application.
Claims
1. An emergency power supply system for a nuclear power plant, characterized in that, include: An emergency diesel generator set, comprising multiple small-power diesel generators (40), each of which has a maximum power of no more than 2400KW; Multiple built-in auxiliary systems are provided, and each built-in auxiliary system corresponds one-to-one with the small-power diesel generator (40). Each built-in auxiliary system is integrated into the corresponding small-power diesel generator (40). An external auxiliary system, comprising a fuel system and an exhaust system, wherein each of the small-power diesel generators (40) is connected to the fuel system and the exhaust system respectively.
2. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The built-in auxiliary systems include a high-temperature water system, a low-temperature water system, a compressed air system, an air intake system, and a lubricating oil system.
3. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The fuel system includes a main fuel storage tank (10), a fuel supply header (20), multiple fuel supply branch pipes (21), and multiple daily fuel tanks (11). The main oil storage tank (10) is connected to the main oil supply pipe (20), and multiple oil supply branch pipes (21) are respectively connected to the main oil supply pipe (20). The daily oil tank (11) is connected between the oil supply branch pipe (21) and the small-power diesel generator (40).
4. The nuclear power plant emergency power supply system according to claim 3, characterized in that, The oil supply branch pipe (21) is equipped with a control valve (31), which controls its opening and closing according to the liquid level information of the daily oil tank (11).
5. The nuclear power plant emergency power supply system according to claim 4, characterized in that, The fuel system also includes a bypass pipeline (22), which is connected between the fuel supply main pipe (20) and the daily fuel tank (11) and is set in parallel with the fuel supply branch pipe (21).
6. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The nuclear power plant emergency power system also includes an electrical primary control system, which includes a parallel bus (50). The output terminals of each of the small-power diesel generators (40) are respectively connected to the parallel bus (50), and the parallel bus (50) is connected to the nuclear power plant's emergency power bus (51).
7. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The nuclear power plant emergency power system also includes an electrical secondary control system, which includes a parallel control cabinet (60) and multiple controllers (61). The controllers (61) and the small-power diesel generators (40) are connected in a one-to-one correspondence, and each controller (61) is connected to the parallel control cabinet (60).
8. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The nuclear power plant emergency power supply system also includes an electrical secondary control system, which includes a first instrument control cabinet (62). The first instrument control cabinet (62) is connected to the external auxiliary system and the internal auxiliary system respectively, and is used to control the operation of the external auxiliary system and the internal auxiliary system.
9. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The nuclear power plant emergency power supply system also includes an electrical secondary control system, which includes a second instrument control cabinet (63). The second instrument control cabinet (63) is connected to the external auxiliary system and the built-in auxiliary system respectively, and is used to display the parameter information and alarm information of the external auxiliary system and the built-in auxiliary system.
10. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The nuclear power plant emergency power system also includes a battery bank. The battery bank and the emergency diesel generator set are respectively located in different rooms in the nuclear power plant building. The battery bank is connected to each of the small-power diesel generators (40) to provide power to the starter motors of each of the small-power diesel generators (40).
11. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The nuclear power plant emergency power system also includes a 24V conversion cabinet and a 24V switch cabinet, which are connected by cables to provide 24V control power to each load device.
12. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The nuclear power plant emergency power system also includes an electrical secondary control system and a fault recorder. The electrical secondary control system includes at least one of a parallel control cabinet (60), a controller (61), a first instrument control cabinet (62), and a second instrument control cabinet (63). Multiple controllers (61) are connected one-to-one with the small-power diesel generator (40), and each controller (61) is connected to the parallel control cabinet (60); the first instrument control cabinet (62) is connected to the external auxiliary system and the built-in auxiliary system respectively, and is used to control the operation of the external auxiliary system and the built-in auxiliary system; the second instrument control cabinet (63) is connected to the external auxiliary system and the built-in auxiliary system respectively, and is used to display the parameter information and alarm information of the external auxiliary system and the built-in auxiliary system. The fault recorder is connected to at least one of the parallel control cabinet (60), controller (61), first instrument control cabinet (62), and second instrument control cabinet (63) for fault recording of electrical parameters.
13. The nuclear power plant emergency power supply system according to claim 1, characterized in that, All of the aforementioned small-power diesel generators (40) are housed in the same room within the nuclear power plant building; And / or, the external auxiliary systems are integrated with the auxiliary and support systems of the nuclear power plant.
14. The nuclear power plant emergency power supply system according to claim 1, characterized in that, The sum of the rated power of each of the aforementioned small-power diesel generators (40) is greater than the rated power required by the nuclear power plant emergency power system.
15. The nuclear power plant emergency power supply system according to claim 14, characterized in that, The plurality of small-power diesel generators (40) include a plurality of main diesel engines and at least one standby diesel engine, wherein the sum of the rated power of each of the main diesel engines is greater than or equal to the rated power required by the nuclear power plant emergency power system, and the sum of the rated power of each of the main diesel engines and the standby diesel engine is greater than the rated power required by the nuclear power plant emergency power system.
16. The nuclear power plant emergency power supply system according to claim 15, characterized in that, The rated power of the primary diesel engine and the rated power of the standby diesel engine are equal.