Emergency power supply system of nuclear power plant
By setting up separate emergency power systems for the nuclear island and conventional island, and using non-safety-grade diesel generators specifically designed for the conventional island, the problem of high-cost diesel generators for the nuclear island was solved, achieving the effects of reducing engineering costs and improving the reliability of emergency power supplies.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2026-03-06
AI Technical Summary
Existing nuclear power plants' conventional island emergency power systems rely on high-cost nuclear island emergency diesel generators, leading to increased engineering costs and insufficient reliability, resulting in a lack of economical and reliable emergency power solutions.
The emergency power systems for the nuclear island and conventional island are set up separately. The capacity of the diesel generator on the nuclear island is reduced, and a non-safety-grade diesel generator for the conventional island is used. An independent emergency power system is set up to improve reliability.
This reduced the capacity and engineering cost of the nuclear island diesel generators, while improving the reliability of the nuclear island emergency power supply and ensuring the reliability of the conventional island emergency power supply.
Smart Images
Figure CN223978477U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of nuclear power, and more specifically to an emergency power supply system for nuclear power plants. Background Technology
[0002] The emergency power supply system of the conventional island of a nuclear power plant mainly provides a safe, reliable, and continuous power supply for emergency loads on the conventional island. Emergency loads on the conventional island of a nuclear power plant refer to loads that should continue to be powered by AC emergency power supply in the event of a plant-wide power outage or when a unit loses its auxiliary power supply, in order to ensure the safe shutdown of the turbine generator units or to prevent endangerment of personal safety.
[0003] Currently, the emergency power system of the conventional island of the nuclear power plant consists of a 10 / 0.4kV dry-type transformer and a 380V low-voltage AC distribution panel. The 10kV power supply is drawn from the nuclear island's 10kV emergency bus A via cables. Under normal circumstances, the 10kV emergency bus is supplied by the high-voltage plant service transformer through the 10kV service bus B and C respectively; in the event of an accident, it switches to the auxiliary transformer, still supplying power through the service bus B and C respectively; when both of the above power sources are lost, the nuclear island's 10kV emergency diesel generator set supplies power to this bus.
[0004] Emergency diesel generators in nuclear power plants serve as the plant's emergency safety power source and are directly related to nuclear safety. Their purpose is to ensure a safe shutdown of the unit and prevent damage to critical equipment when both the plant's main power supply and auxiliary power supplies fail. Therefore, they play a crucial role in protecting fuel elements from damage and ensuring nuclear safety.
[0005] However, the emergency diesel generators for nuclear islands are classified as Class 1E equipment, using a 10kV voltage level, and most of the system equipment they power is nuclear safety grade. Due to the high safety level of the equipment, China currently lacks the capability for independent design and manufacturing. Almost all existing nuclear power diesel generator sets are imported from MTU / AREVA in Germany and ALSTOM in France, making them extremely expensive.
[0006] In recent years, due to the continuous expansion of the design capacity of nuclear power plant units, the emergency load of the nuclear island and conventional island has increased dramatically, and the required capacity of the nuclear island emergency diesel generator has also increased accordingly. This has not only brought difficulties to the design and selection, but also increased the engineering cost.
[0007] Therefore, there is currently a lack of solutions in this field that can improve the reliability of emergency power supplies for nuclear islands more economically while ensuring the reliability of emergency power supplies for conventional islands. Utility Model Content
[0008] The purpose of this invention is to provide an emergency power supply system for nuclear power plants, which can effectively reduce the capacity of diesel generators in the nuclear island, reduce engineering costs, and improve the reliability of emergency power supply in the nuclear island while ensuring the reliability of emergency power supply in the conventional island.
[0009] This utility model provides an emergency power supply system for a nuclear power plant, the system comprising:
[0010] First emergency busbar;
[0011] The first working busbar is connected to the first emergency busbar;
[0012] The first auxiliary busbar is connected to the first working busbar and is also connected to the first emergency busbar via the first working busbar; and
[0013] A conventional island emergency power supply system is connected to the first working bus. The conventional island emergency power supply system includes a transformer connected to the first working bus, a conventional island 380V emergency bus connected to the transformer, and a conventional island 380V diesel generator connected to the conventional island 380V emergency bus.
[0014] In another preferred embodiment, the first emergency bus is connected to the first nuclear island diesel generator.
[0015] In another preferred embodiment, the first nuclear island diesel generator is a nuclear island 10kV diesel generator.
[0016] In another preferred embodiment, the first emergency busbar is a 10kV emergency busbar.
[0017] In another preferred embodiment, the first working bus is a 10kV working bus.
[0018] In another preferred embodiment, the first auxiliary bus is a 10kV auxiliary bus.
[0019] In another preferred embodiment, the first auxiliary bus is connected to the first auxiliary transformer.
[0020] In another preferred embodiment, the system further includes a second emergency bus, a second working bus, and a second auxiliary bus, wherein the second emergency bus is connected to the second working bus, the second auxiliary bus is connected to the second working bus, and is connected to the second emergency bus through the second working bus.
[0021] In another preferred embodiment, the second emergency busbar is a 10kV emergency busbar.
[0022] In another preferred embodiment, the second working bus is a 10kV working bus.
[0023] In another preferred embodiment, the second auxiliary busbar is a 10kV auxiliary busbar.
[0024] In another preferred embodiment, the second emergency bus is connected to the diesel generator of the second nuclear island.
[0025] In another preferred embodiment, the second nuclear island diesel generator is a nuclear island 10kV diesel generator.
[0026] In another preferred embodiment, the second auxiliary busbar is connected to the second auxiliary transformer.
[0027] In another preferred embodiment, the first auxiliary busbar and the second auxiliary busbar are connected.
[0028] In another preferred embodiment, the first working busbar is connected to the high-voltage plant transformer.
[0029] In another preferred embodiment, the first working busbar is connected to the high-voltage plant transformer via a third working busbar.
[0030] In another preferred embodiment, the third working bus is a 10kV working bus.
[0031] In another preferred embodiment, the second working busbar is connected to the high-voltage plant transformer.
[0032] In another preferred embodiment, the second working busbar is connected to the high-voltage plant transformer via a fourth working busbar.
[0033] In another preferred embodiment, the fourth working bus is a 10kV working bus.
[0034] In another preferred embodiment, the high-voltage plant transformer is connected to the main line and is connected between the main transformer and the generator on the main line.
[0035] In another preferred embodiment, the conventional island 380V diesel generator is located in a dedicated diesel generator room near the conventional island plant and supplies power to the conventional island 380V emergency bus via cable.
[0036] It should be understood that, within the scope of this utility model, the above-described technical features of this utility model and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art 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.
[0038] Figure 1This is a circuit diagram of an emergency power supply system for a nuclear power plant, as exemplified by this utility model. Detailed Implementation
[0039] Through extensive and in-depth research and screening, the inventors have developed, for the first time, an emergency power supply system for nuclear power plants. Compared with existing technologies, this invention sets up separate emergency power supply systems for the nuclear island and conventional island, ensuring they do not interfere with each other. This reduces the capacity of the nuclear island diesel generators while improving the reliability of the nuclear island's emergency power supply. Simultaneously, it simplifies wiring and equipment. Furthermore, the independent emergency power supply system for the conventional island also guarantees its reliability. This invention was completed based on these findings.
[0040] The main advantages of this utility model include:
[0041] (a) It can effectively reduce the capacity of the nuclear island diesel generator, simplify the wiring, and reduce the project cost;
[0042] (b) While ensuring the reliability of the emergency power supply on the conventional island, the reliability of the emergency power supply on the nuclear island has been improved.
[0043] (c) The emergency power supply systems for the nuclear island and conventional island are set up separately so that they do not affect each other, which reduces the requirements for emergency power supply.
[0044] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, the accompanying drawings are schematic diagrams, and therefore the device and apparatus of the present invention are not limited to the size or scale of the schematic diagrams.
[0045] It should be noted that in the claims and specification of this patent, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0046] Example
[0047] The nuclear power plant emergency power supply system in this embodiment is as follows: Figure 1As shown. In the emergency power system of this nuclear power plant, the high-voltage plant transformer is connected to the main line and is connected between the main transformer and the generator on the main line. The system has four working buses: 10kV working bus A, 10kV working bus B, 10kV working bus C, and 10kV working bus D. Among them, 10kV working bus A and 10kV working bus D are directly connected to the high-voltage plant transformer, 10kV working bus B is connected to 10kV working bus A, and 10kV working bus C is connected to 10kV working bus D. 10kV emergency bus A is connected to 10kV working bus B, and 10kV emergency bus B is connected to 10kV working bus C. 10kV emergency bus A and 10kV emergency bus B are also connected to a 10kV diesel generator on the nuclear island. In addition, 10kV working busbar B is connected to a 10kV auxiliary busbar A, and 10kV working busbar C is connected to a 10kV auxiliary busbar B. 10kV auxiliary busbar A is connected to auxiliary transformer A, and 10kV auxiliary busbar B is connected to auxiliary transformer B. 10kV auxiliary busbar A is also connected to 10kV auxiliary busbar B.
[0048] The emergency power supply system of the conventional island is connected to the 10kV working bus B, with the transformer directly connected to the 10kV working bus B. The 380V emergency bus of the conventional island is connected to the transformer, and the 380V diesel generator of the conventional island is connected to the 380V emergency bus of the conventional island.
[0049] The high-voltage side power supply of the 10 / 0.4kV emergency transformer on the conventional island is connected to either the 10kV working busbar B or C. A dedicated 380V diesel generator with rapid start is installed on the conventional island. Under normal circumstances, the emergency power supply for the conventional island is led from the 10kV working busbar B or C via cable, and the 10kV working busbar B or C is powered by the high-voltage plant service transformer. When the high-voltage plant transformer loses power, the 10kV working busbar B or C switches to the auxiliary transformer. When both of the above power supplies are lost, the 380V diesel generator connected to the 380V emergency busbar on the conventional island provides power.
[0050] The diesel generator is planned to be located in a dedicated diesel generator room near the conventional island plant, supplying power to the conventional island's 380V emergency busbar via cable. This diesel generator is a non-safety grade device with low voltage, small capacity, and low cost.
[0051] Nuclear island emergency plant equipment is safety-grade (Class 1E) plant equipment used to prevent, limit, and reduce the leakage of radioactive materials, while conventional island emergency plant equipment is non-safety-grade equipment used to ensure the safe shutdown and operation of steam turbine generator units.
[0052] This invention utilizes this feature to separate the emergency power systems for the nuclear island and conventional island, ensuring they do not interfere with each other. This reduces the capacity of the nuclear island's diesel generators while improving the reliability of the nuclear island's emergency power supply. Simultaneously, the independent emergency power system for the conventional island also guarantees its reliability.
[0053] All documents mentioned in this invention are incorporated herein by reference as if each document were individually incorporated by reference. Furthermore, it should be understood that after reading the foregoing teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by the appended claims.
Claims
1. A nuclear power plant emergency power supply system, characterized by, The system comprises: a first emergency bus; a first working bus connected to the first emergency bus; a first auxiliary bus connected to the first working bus and to the first emergency bus through the first working bus; and a conventional island emergency power supply system connected to the first working bus, the conventional island emergency power supply system comprising a transformer connected to the first working bus, a conventional island 380V emergency bus connected to the transformer, and a conventional island 380V diesel generator connected to the conventional island 380V emergency bus.
2. The system of claim 1, wherein, The first emergency bus is connected to a first nuclear island diesel generator.
3. The system of claim 1, wherein, The system further comprises a second emergency bus, a second working bus, and a second auxiliary bus, wherein the second emergency bus is connected to the second working bus, and the second auxiliary bus is connected to the second working bus and to the second emergency bus through the second working bus.
4. The system of claim 3, wherein, The second emergency bus is connected to a second nuclear island diesel generator.
5. The system of claim 3, wherein, The first auxiliary bus is connected to a first auxiliary transformer, and the second auxiliary bus is connected to a second auxiliary transformer.
6. The system of claim 1, wherein, The first working bus is connected to a high voltage plant transformer.
7. The system of claim 6, wherein, The first working bus is connected to the high voltage plant transformer through a third working bus.
8. The system of claim 3, wherein, The second working bus is connected to the high voltage plant transformer.
9. The system of claim 8, wherein, The second working bus is connected to the high voltage plant transformer through a fourth working bus.
10. The system of claim 1, wherein, The conventional island 380V diesel generator is arranged in a dedicated diesel generator room near a conventional island plant building, and supplies power to the conventional island 380V emergency bus through a cable.