DCS Two-Layer Network System of Nuclear Power Plant

Abstract

The present invention relates to a DCS two-layer network system for a nuclear power plant. The DCS two-layer network system includes a SCID ring network subsystem and an MNET ring network subsystem. The SCID ring network subsystem includes: a plurality of first SCID devices of an operator workstation disposed in a main control room; a plurality of second SCID devices of a simplified operator workstation disposed in a remote shutdown station; a first gateway module; a second gateway module; the plurality of first SCID devices are sequentially connected through corresponding ring network switches in a preset order to form a first branch line, and the plurality of second SCID devices are sequentially connected through corresponding ring network switches in a preset order to form a second branch line. One end of the first branch line and one end of the second branch line are respectively connected to the MNET ring network subsystem through the first gateway module, and the other end of the first branch line and the other end of the second branch line are respectively connected to the MNET ring network subsystem through the second gateway module. Through this technical solution, the independence of the main control room and the remote shutdown station is improved, and the reliability of nuclear power plant monitoring is greatly enhanced.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power, and in particular to a DCS two-layer network system for a nuclear power plant. Background Art

[0002] The main control room (MCR, Main Control Room) is the centralized operation area of the power plant. The main control room contains the equipment for the operators to monitor and maintain the power plant. Almost all operations of the power plant under all working conditions are completed in the main control room. As shown in Figure 1 the main control room shown, the main equipment includes four OWP (Operator Working Place, operator workstations), namely: NI-OWP (Nuclear Island OWP, nuclear island operator workstation), CI-OWP (Conventional Island OWP, conventional island operator workstation), US-OWP (Unit Supervisor OWP, unit supervisor workstation), SE-OWP (Safety Engineer OWP, safety engineer station). Multiple (for example, four) SCID (Safety Control and Information Device, safety control display devices) can be equipped on each OWP for the operation and information display of safety-class equipment.

[0003] The remote shutdown station (RSS, Remote Shutdown Station) is a place where the operators evacuate and shut down the reactor and enter a safe state in case of an emergency (such as a fire) when the main control room is unavailable. The control authority can be switched from the main control room to the remote shutdown station through a changeover switch. As shown in Figure 2 the remote shutdown station shown, the main equipment mainly includes three COWP (Compact Operator Working Place, simplified operator workstations), namely: NI-COWP (nuclear island simplified operator workstation), CI-COWP (conventional island simplified operator workstation), US-COWP (unit supervisor simplified workstation). Multiple (for example, four) SCID are equipped on each COWP, which are also used for the operation and information display of safety-class equipment. In addition, the remote shutdown station and the main control room are located in different rooms on different floors, achieving physical isolation.

[0004] In addition, the nuclear power plant is also equipped with a Computer Room (CR) and a Technical Support Center (TSC). Among them, the equipment in the CR is not in the main control room and mainly serves auxiliary functions such as configuration, maintenance, backup, and software downloading. The TSC is a place where on-site expert groups evaluate and diagnose the plant conditions in case of emergencies in the nuclear power plant, so as to provide consultation and assistance for the management and technology of the plant. The operation and status of the nuclear power plant can be monitored and analyzed in the Technical Support Center, but the control function of the plant is not provided.

[0005] The monitoring equipment of the nuclear power plant needs to form a local area network through switches and network transmission media for information collection, display, transmission, and instruction issuance. For example, the IO server (Input Output server) and the computing server need to send the data sent by the first and second layers and the computed and processed data to each device. At the same time, the screen adjustment and navigation functions also need to be realized through the network. Moreover, the network often appears in the form of a ring network. The ring network can prevent the entire network from losing due to the loss of a certain node. The switches are connected in a ring shape (the medium is optical cable), and the devices of the system are connected to the switches in a star structure (the medium is twisted pair).

[0006] Figure 3 The schematic diagram of the network system of the nuclear power plant is shown. Among them, MNET (Monitoring Net) is the monitoring network, VDU (Visual Display Unit) is the video display device, that is, the display screen; SNET (System Net) is the system network, which is used in cooperation with the monitoring network to perform data acquisition and logic processing functions.

[0007] The SCID devices of the operator workstations in the main control room and the simplified operator workstations in the remote shutdown stations need to form a local area network through switches and network transmission media. As Figure 4 shown, the various SCID devices of the operator workstations in the main control room and the simplified operator workstations in the remote shutdown stations are connected through a safety bus to form a SCID ring network to realize functions such as instruction issuance, first-layer data display, and second-layer screen adjustment. Then combined with Figure 1 and Figure 2, the SCIDs on the four OWPs in the main control room are the four groups of numbers 1, 3, 5, and 7 respectively, and each group contains four SCIDs: A, B, C, and D; the SCIDs on the three COWPs in the remote shutdown station are the three groups of numbers 2, 4, and 6 respectively, and each group contains four SCID screens: A, B, C, and D. However, in this SCID ring network solution, there are 6 cables in the safety bus directly connecting the SCIDs in the main control room and the remote shutdown station, without achieving electrical isolation. This method has a common mode point, resulting in weak independence between the main control room and the remote shutdown station and being unable to avoid the spread of faults. Therefore, the reliability of nuclear power plant monitoring is reduced.

[0008] In addition, as Figure 3 shown, the monitoring devices of the nuclear power plant are also connected in the form of a ring network to form an MNET (Monitoring Net), and logically, this MNET is divided into two parts: Train A and Train B (Column A and Column B), and these two parts are physically connected by optical cables. In the Figure 5 shown monitoring ring network system (only the part of Column A is shown), the switch (KIC1303WS) in the computer room of the MNET and the switch (KIC1401WS) in the technical support center are connected in series and form a separate branch line and then connected to the switch (KIC1101WS) in the main control room. If the switch in the main control room fails, it will cause the switches in the computer room and the technical support center to go offline and be unable to send and receive data, and the devices in the computer room and the technical support center connected to them will also go offline and be unable to send and receive data. Therefore, the reliability of nuclear power plant monitoring is further reduced. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a DCS two-layer network system for a nuclear power plant in view of the defect of low reliability of nuclear power plant monitoring existing in the prior art.

[0010] The technical solution adopted by the present invention to solve its technical problem is to construct a DCS two-layer network system for a nuclear power plant, including a connected SCID ring network subsystem and an MNET ring network subsystem. The SCID ring network subsystem includes:

[0011] Multiple first SCID devices of the operator workstation set in the main control room;

[0012] Multiple second SCID devices of the simplified operator workstation set in the remote shutdown station;

[0013] The first gateway module;

[0014] The second gateway module;

[0015] Among them, the multiple first SCID devices are sequentially connected through corresponding Ethernet switches in a preset order to form a first branch line, and the multiple second SCID devices are sequentially connected through corresponding Ethernet switches in a preset order to form a second branch line. One end of the first branch line and one end of the second branch line are respectively connected to the MNET Ethernet subsystem through the first gateway module, and the other end of the first branch line and the other end of the second branch line are respectively connected to the MNET Ethernet subsystem through the second gateway module.

[0016] Preferably, the first gateway module includes two first gateway devices with redundant settings;

[0017] The second gateway module includes two second gateway devices with redundant settings.

[0018] Preferably, there are four operator workstations arranged in the main control room, and three simplified operator workstations are arranged in the remote shutdown station. Moreover,

[0019] The multiple first SCID devices include: SCID-A1, SCID-B1, SCID-C1, SCID-D1 corresponding to the first operator workstation; SCID-A3, SCID-B3, SCID-C3, SCID-D3 corresponding to the second operator workstation; SCID-A5, SCID-B5, SCID-C5, SCID-D5 corresponding to the third operator workstation; SCID-A7, SCID-B7, SCID-C7, SCID-D7 corresponding to the fourth operator workstation;

[0020] The multiple second SCID devices include: SCID-A2, SCID-B2, SCID-C2, SCID-D2 corresponding to the first simplified operator workstation; SCID-A4, SCID-B4, SCID-C4, SCID-D4 corresponding to the second simplified operator workstation; SCID-A6, SCID-B6, SCID-C6, SCID-D6 corresponding to the third simplified operator workstation.

[0021] Preferably, in the first branch line, the connection order of the multiple first SCID devices is: SCID-A1, SCID-A3, SCID-A5, SCID-A7, SCID-C1, SCID-C3, SCID-C5, SCID-C7, SCID-D1, SCID-D3, SCID-D5, SCID-D7, SCID-B1, SCID-B3, SCID-B5, SCID-B7;

[0022] In the second branch line, the connection sequence of the multiple second SCID devices is: SCID-A2, SCID-A4, SCID-A6, SCID-C2, SCID-C4, SCID-C6, SCID-D2, SCID-D4, SCID-D6, SCID-B2, SCID-B4, SCID-B6.

[0023] Preferably, the MNET ring network subsystem includes: multiple main switches arranged in the plant network cabinets of the nuclear power plant, multiple first sub-switches arranged in the main control room, multiple second sub-switches arranged in the remote shutdown station, a third sub-switch arranged in the computer room, and a fourth sub-switch arranged in the technical support center. Moreover, each main switch respectively forms a sub-ring with the corresponding first sub-switch or the corresponding second sub-switch through the corresponding optical fiber interface, and the third sub-switch and the fourth sub-switch are respectively connected to the corresponding optical fiber interfaces of the corresponding main switches.

[0024] Preferably, the MNET ring network subsystem is a single-ring network system, and in the single-ring network system,

[0025] The number of the main switches is four. Moreover, two of the main switches are the main switches of column A and are arranged in the network cabinets in area A of the safety plant; the other two main switches are the main switches of column B and are arranged in the network cabinets in area B of the safety plant;

[0026] The number of the first sub-switches is four. Moreover, two of the first sub-switches are the first sub-switches of column A and are respectively connected to the two operator workstations of column A in one-to-one correspondence; the other two first sub-switches are the first sub-switches of column B and are respectively connected to the two operator workstations of column B in one-to-one correspondence;

[0027] The number of the second sub-switches is three. Moreover, two of the second sub-switches are the second sub-switches of column A and are respectively connected to the two simplified operator workstations of column A in one-to-one correspondence; the other second sub-switch is the second sub-switch of column B and is connected to one simplified operator workstation of column B in one-to-one correspondence;

[0028] The number of the third sub-switches is two, and they are respectively the third sub-switches of column A and column B;

[0029] The number of the fourth sub-switches is two, and they are respectively the fourth sub-switches of column A and column B.

[0030] Preferably, one of the main switches in column A and one of the main switches in column B both include at least five optical fiber interfaces, where,

[0031] Two of the optical fiber interfaces of one of the main switches in Column A form a sub-ring through the second sub-switch in Column A. The third optical fiber interface of one of the main switches in Column A is connected to another main switch in Column A. The fourth optical fiber interface of one of the main switches in Column A is connected to the third sub-switch in Column A. The fifth optical fiber interface of one of the main switches in Column A is connected to the fourth sub-switch in Column A.

[0032] Two of the optical fiber interfaces of one of the main switches in Column B form a sub-ring through the second sub-switch in Column B. The third optical fiber interface of one of the main switches in Column B is connected to another main switch in Column B. The fourth optical fiber interface of one of the main switches in Column B is connected to the third sub-switch in Column B. The fifth optical fiber interface of one of the main switches in Column B is connected to the fourth sub-switch in Column B.

[0033] Preferably, one of the main switches in Column A and one of the main switches in Column B each include at least five optical fiber interfaces. Among them,

[0034] Two of the optical fiber interfaces of one of the main switches in Column A form a sub-ring through the first sub-switch in Column A. The third optical fiber interface of one of the main switches in Column A is connected to another main switch in Column A. The fourth optical fiber interface of one of the main switches in Column A is connected to the third sub-switch in Column A. The fifth optical fiber interface of one of the main switches in Column A is connected to the fourth sub-switch in Column A.

[0035] Two of the optical fiber interfaces of one of the main switches in Column B form a sub-ring through the first sub-switch in Column B. The third optical fiber interface of one of the main switches in Column B is connected to another main switch in Column B. The fourth optical fiber interface of one of the main switches in Column B is connected to the third sub-switch in Column B. The fifth optical fiber interface of one of the main switches in Column B is connected to the fourth sub-switch in Column B.

[0036] Preferably, the MNET ring network subsystem is a dual-ring network system, and the dual-ring network system includes two single-ring network systems with redundant configurations.

[0037] Preferably, the MNET ring network subsystem is a ring network subsystem formed based on ERPS.

[0038] In the technical solution provided by the present invention, through the improvement of the network topology wiring, the SCID devices in the main control room and the remote shutdown station are respectively connected to the gateway module, and the SCID devices directly connected between the main control room and the remote shutdown station are isolated by the gateway module, which improves the independence between the main control room and the remote shutdown station, truly realizes the physical isolation and electrical isolation between the main control room and the remote shutdown station, avoids the spread of network failures between the two, and at the same time does not affect the communication and data transmission functions. Therefore, the reliability of nuclear power plant monitoring is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. In the drawings:

[0040] Figure 1 is the layout structure diagram of the main control room in the nuclear power plant;

[0041] Figure 2 is the layout structure diagram of the remote shutdown station in the nuclear power plant;

[0042] Figure 3 is the schematic diagram of the network system of the nuclear power plant;

[0043] Figure 4 is the schematic diagram of a SCID ring network system in the prior art;

[0044] Figure 5 is the schematic diagram of a MNET ring network system in the prior art;

[0045] Figure 6 is the structural schematic diagram of an embodiment of the DCS two-layer network system of the nuclear power plant of the present invention;

[0046] Figure 7 is Figure 6 the structural schematic diagram of an embodiment of the SCID ring network subsystem in

[0047] Figure 8 is Figure 6 the structural schematic diagram of an embodiment of the MNET ring network subsystem in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] Figure 6 FIG. 4 is a schematic structural diagram of an embodiment of the DCS two-layer network system of a nuclear power plant according to the present invention. The DCS two-layer network system of this embodiment includes a connected SCID ring network subsystem 100 and an MNET ring network subsystem 200. Moreover, since each SCID device in the SCID ring network subsystem 100 is a safety-class device, while other devices (such as VDUs) in the operator workstation and the simplified operator workstation are non-safety-class devices, therefore, it is necessary to connect the SCID ring network subsystem 100 and the MNET ring network subsystem 200 through a gateway. In addition, as a backup control room in the case where the main control room is unavailable due to disasters (such as fires), the remote shutdown station needs to meet the independence from the main control room, that is, it is necessary to ensure the physical isolation and electrical isolation of each SCID device of the operator workstation in the main control room and the simplified operator workstation of the remote shutdown station. As Figure 6 shown, the SCID ring network subsystem 100 includes: a plurality of first SCID devices M1, M2,..., M3; a plurality of second SCID devices R1, R2,..., R3; a first gateway module GW1; a second gateway module GW2, wherein, a plurality of first SCID devices M1, M2,..., M3 are arranged in the operator workstation of the main control room, and a plurality of second SCID devices R1, R2,..., R3 are arranged in the simplified operator workstation of the remote shutdown station, thus realizing the physical isolation of each SCID device of the operator workstation in the main control room and the simplified operator workstation of the remote shutdown station. Moreover, a plurality of first SCID devices M1, M2,..., M3 are sequentially connected through corresponding ring network switches in a preset order to form a first branch line, and a plurality of second SCID devices R1, R2,..., R3 are sequentially connected through corresponding ring network switches in a preset order to form a second branch line. One end of the first branch line and one end of the second branch line are respectively connected to the MNET ring network subsystem 200 through the first gateway module GW1, and the other end of the first branch line and the other end of the second branch line are respectively connected to the MNET ring network subsystem 200 through the second gateway module GW2, thus realizing the electrical isolation of each SCID device of the operator workstation in the main control room and the simplified operator workstation of the remote shutdown station.

[0050] In the technical solution of this embodiment, through the improvement of the network topology wiring, the SCID devices in the main control room and the remote shutdown station are respectively connected to the gateway module, and the SCID devices directly connected between the main control room and the remote shutdown station are isolated by the gateway module, which improves the independence between the main control room and the remote shutdown station, truly realizes the physical isolation and electrical isolation between the main control room and the remote shutdown station, and avoids the spread of network failures between the two. At the same time, it does not affect the communication and data transmission functions. Therefore, the reliability of nuclear power plant monitoring is greatly improved.

[0051] Figure 7 Yes Figure 6 It is a schematic structural diagram of an embodiment of the SCID ring network subsystem. In this embodiment, four operator workstations are arranged in the main control room (MCR), and three simplified operator workstations are arranged in the remote shutdown station (RSS). Moreover, the four operator workstations in the main control room are numbered 1, 3, 5, and 7 respectively, and each group contains four SCID devices A, B, C, and D; the three simplified operators in the remote shutdown station are numbered 2, 4, and 6 respectively, and each group also contains four SCID devices A, B, C, and D. Therefore, there are 16 first SCID devices and 12 second SCID devices in total. Moreover, the 16 first SCID devices include: SCID-A1, SCID-B1, SCID-C1, SCID-D1 corresponding to the first operator workstation; SCID-A3, SCID-B3, SCID-C3, SCID-D3 corresponding to the second operator workstation; SCID-A5, SCID-B5, SCID-C5, SCID-D5 corresponding to the third operator workstation; SCID-A7, SCID-B7, SCID-C7, SCID-D7 corresponding to the fourth operator workstation. The 12 second SCID devices include: SCID-A2, SCID-B2, SCID-C2, SCID-D2 corresponding to the first simplified operator workstation; SCID-A4, SCID-B4, SCID-C4, SCID-D4 corresponding to the second simplified operator workstation; SCID-A6, SCID-B6, SCID-C6, SCID-D6 corresponding to the third simplified operator workstation.

[0052] Moreover, as Figure 7As shown, in the first branch line, the connection order of 16 first SCID devices is: SCID-A1, SCID-A3, SCID-A5, SCID-A7, SCID-C1, SCID-C3, SCID-C5, SCID-C7, SCID-D1, SCID-D3, SCID-D5, SCID-D7, SCID-B1, SCID-B3, SCID-B5, SCID-B7; in the second branch line, the connection order of 12 second SCID devices is: SCID-A2, SCID-A4, SCID-A6, SCID-C2, SCID-C4, SCID-C6, SCID-D2, SCID-D4, SCID-D6, SCID-B2, SCID-B4, SCID-B6.

[0053] Of course, in other embodiments, the number of SCID devices configured in the operator workstation in the main control room and the simplified operator workstation in the remote shutdown station may be other numbers.

[0054] Regarding the technical problem that the switches in the computer room and the technical support center in the prior art may be offline and unable to send and receive data, after analyzing the existing MNET solution, it is found that the reason for the separate series connection of the computer room and the technical support center into branch lines is that the number of optical ports of the network cabinet switch is insufficient, resulting in the computer room and the technical support center being forced to connect to other nodes. Based on this, in an embodiment of the present invention, the MNET ring network subsystem includes: a plurality of main switches provided in the plant network cabinet of the nuclear power plant, a plurality of first sub-switches provided in the main control room, a plurality of second sub-switches provided in the remote shutdown station, a third sub-switch provided in the computer room, and a fourth sub-switch provided in the technical support center. Moreover, each main switch forms a sub-ring with the corresponding first sub-switch or the corresponding second sub-switch through the corresponding optical fiber interface, and the third sub-switch and the fourth sub-switch are respectively connected to the corresponding optical fiber interface of the corresponding main switch. In this embodiment, a new network topology structure is built by increasing the optical fiber interfaces of the main switch (for example, changing from the original four optical fiber interfaces to six optical fiber interfaces), so that the third sub-switch provided in the computer room and the fourth sub-switch provided in the technical support center are directly connected to the main switch provided in the plant network cabinet of the nuclear power plant. In this way, on the basis of maintaining the original data transmission and communication functions unchanged, the problem of the series branch line being offline in the original solution is avoided, the stability of the network is improved, the situation where a single node fails and causes many other nodes to be offline is avoided, and an interface is reserved for subsequent flexible transformation. Therefore, the new MNET network topology solution improves the reliability of nuclear power plant monitoring.

[0055] Figure 8 Yes Figure 6Structural schematic diagram of an embodiment of the MNET ring network subsystem. In this embodiment, the MNET ring network subsystem is a single-ring network system, and in the single-ring network system:

[0056] The number of main switches is four. Moreover, two of the main switches 211 and 212 are the main switches of column A and are arranged in the network cabinet in area A of the security plant; the other two main switches 213 and 214 are the main switches of column B and are arranged in the network cabinet in area B of the security plant.

[0057] The number of first sub-switches is four. Moreover, two of the first sub-switches 221 and 222 are the first sub-switches of column A and are respectively and correspondingly connected to two operator workstations in column A; the other two first sub-switches 223 and 224 are the first sub-switches of column B and are respectively and correspondingly connected to two operator workstations in column B.

[0058] The number of second sub-switches is three. Moreover, two of the second sub-switches 231 and 232 are the second sub-switches of column A and are respectively and correspondingly connected to two simplified operator workstations in column A; the other second sub-switch 233 is the second sub-switch of column B and is respectively and correspondingly connected to one simplified operator workstation in column B.

[0059] The number of third sub-switches is two, namely the third sub-switch 241 of column A and the third sub-switch 242 of column B respectively.

[0060] The number of fourth sub-switches is two, namely the fourth sub-switch 251 of column A and the fourth sub-switch 252 of column B respectively.

[0061] Moreover, in this embodiment, the main switch 212 of column A and the main switch 214 of column B respectively have at least five optical fiber interfaces. Moreover, two of the optical fiber interfaces of the main switch 212 form a sub-ring through the second sub-switches 231 and 232 of column A. The third optical fiber interface of the main switch 212 is connected to the other main switch 211 of column A. The fourth optical fiber interface of the main switch 212 is connected to the third sub-switch 241 of column A. The fifth optical fiber interface of the main switch 212 is connected to the fourth sub-switch 251 of column A. Two of the optical fiber interfaces of the main switch 214 form a sub-ring through the second sub-switch 233 of column B. The third optical fiber interface of the main switch 214 of column B is connected to the other main switch 213 of column B. The fourth optical fiber interface of the main switch 214 is connected to the third sub-switch 242 of column B. The fifth optical fiber interface of the main switch 214 is connected to the fourth sub-switch 252 of column B.

[0062] In this embodiment, the two rows of switches (the third sub-switches) in columns A and B of the computer room and the two rows of switches (the fourth sub-switches) in columns A and B of the technical support center are directly connected to the main switches of the plant network cabinets in their respective columns. Moreover, the second sub-switches corresponding to the remote shutdown stations in the same columns are connected to the same main switch, avoiding the situation where other nodes go offline due to the failure of a single node (such as the first sub-switch in the main control room). If the network cabinet fails completely, the power plant computer information and control system will be unavailable. At this time, the nuclear power plant needs to be transferred to the ACP (Auxiliary Control Panel) in the main control room for monitoring. Therefore, whether the other nodes connected to the network cabinet are offline is no longer meaningful and does not need to be considered. Therefore, the technical solution of this embodiment has high reliability and availability, providing guarantee for the safe and reliable operation of the nuclear power plant.

[0063] Of course, in some other embodiments, the main switch 211 in column A and the main switch 213 in column B can also be replaced with switches with multiple optical ports (such as at least five fiber optic interfaces). In this way, two of the fiber optic interfaces of the main switch 211 form a sub-ring through the first sub-switches 221 and 222 in column A. The third fiber optic interface of the main switch 211 is connected to another main switch 212 in column A. The fourth fiber optic interface of the main switch 211 is connected to the third sub-switch 241 in column A. The fifth fiber optic interface of the main switch 211 is connected to the fourth sub-switch 251 in column A. Two of the fiber optic interfaces of the main switch 213 form a sub-ring through the first sub-switches 223 and 224 in column B. The third fiber optic interface of the main switch 213 is connected to another main switch 214 in column B. The fourth fiber optic interface of the main switch 213 is connected to the third sub-switch 242 in column B. The fifth fiber optic interface of the main switch 213 is connected to the fourth sub-switch 252 in column B.

[0064] In addition, in some other embodiments, the two main switches 211 and 212 in column A and the two main switches 213 and 214 in column B can all be selected as switches with multiple optical ports (such as six fiber optic interfaces). In this way, in addition to directly connecting the two rows of switches (the third sub-switches 241 and 242) in columns A and B of the computer room and the two rows of switches (the fourth sub-switches 251 and 252) in columns A and B of the technical support center to the main switches of the plant network cabinets in their respective columns, interfaces can also be reserved for subsequent upgrade or transformation plans, such as adding network connections for common units.

[0065] Further, in an optional embodiment, the MNET ring network subsystem is a dual-ring network system, and the dual-ring network system includes two single-ring network systems with redundant configurations. That is, the MNET network has two redundant network segments, Net A and Net B (Network A and Network B). The functions of the two network segments are the same. If one network segment is lost, the other network segment can still achieve complete functions. Logically, each network segment can be further divided into two parts: Train A and Train B (Column A and Column B). These two parts are physically connected by optical cables. Therefore, the total MNET network consists of four parts: Train A Net A, Train B Net A, Train A Net B, and Train B Net B.

[0066] Further, the MNET ring network subsystem is a ring network subsystem formed based on ERPS (Ethernet Ring Protection Switching), that is, the ERPS protocol is used to construct the MNET network.

[0067] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A DCS two-layer network system for a nuclear power plant, comprising a safety control display device ring network subsystem and a monitoring ring network subsystem which are connected to each other, characterized in that, The ring network subsystem of the safety control display device includes: A plurality of first safety control display devices of the operator workstations arranged in the main control room; A plurality of second safety control display devices of the simplified operator workstations arranged in the remote shutdown station; A first gateway module; A second gateway module; Wherein, the plurality of first safety control display devices are sequentially connected through corresponding ring network switches in a preset order to form a first branch line, and the plurality of second safety control display devices are sequentially connected through corresponding ring network switches in a preset order to form a second branch line. One end of the first branch line and one end of the second branch line are respectively connected to the monitoring ring network subsystem through the first gateway module, and the other end of the first branch line and the other end of the second branch line are respectively connected to the monitoring ring network subsystem through the second gateway module.

2. The DCS two-layer network system of a nuclear power plant according to claim 1, wherein The first gateway module includes two first gateway devices arranged redundantly; The second gateway module includes two second gateway devices arranged redundantly.

3. The DCS two-layer network system of a nuclear power plant according to claim 1, wherein There are four operator workstations arranged in the main control room, and three simplified operator workstations are arranged in the remote shutdown station. Moreover, The plurality of first safety control display devices include: SCID-A1, SCID-B1, SCID-C1, SCID-D1 corresponding to the first operator workstation; SCID-A3, SCID-B3, SCID-C3, SCID-D3 corresponding to the second operator workstation; SCID-A5, SCID-B5, SCID-C5, SCID-D5 corresponding to the third operator workstation; SCID-A7, SCID-B7, SCID-C7, SCID-D7 corresponding to the fourth operator workstation; The plurality of second safety control display devices include: SCID-A2, SCID-B2, SCID-C2, SCID-D2 corresponding to the first simplified operator workstation; SCID-A4, SCID-B4, SCID-C4, SCID-D4 corresponding to the second simplified operator workstation; SCID-A6, SCID-B6, SCID-C6, SCID-D6 corresponding to the third simplified operator workstation.

4. The DCS two-layer network system of a nuclear power plant according to claim 3, wherein In the first branch line, the connection order of the plurality of first safety control display devices is: SCID-A1, SCID-A3, SCID-A5, SCID-A7, SCID-C1, SCID-C3, SCID-C5, SCID-C7, SCID-D1, SCID-D3, SCID-D5, SCID-D7, SCID-B1, SCID-B3, SCID-B5, SCID-B7; In the second branch line, the connection sequence of the multiple second safety control display devices is: SCID-A2, SCID-A4, SCID-A6, SCID-C2, SCID-C4, SCID-C6, SCID-D2, SCID-D4, SCID-D6, SCID-B2, SCID-B4, SCID-B6.

5. The DCS two-layer network system of a nuclear power plant according to any one of claims 1-4, characterized in that, The monitoring ring network subsystem includes: multiple main switches arranged in the plant network cabinets of the nuclear power plant, multiple first sub-switches arranged in the main control room, multiple second sub-switches arranged in the remote shutdown station, a third sub-switch arranged in the computer room, and a fourth sub-switch arranged in the technical support center. Moreover, each main switch forms a sub-ring with the corresponding first sub-switch or the corresponding second sub-switch through the corresponding optical fiber interface, and the third sub-switch and the fourth sub-switch are respectively connected to the corresponding optical fiber interfaces of the corresponding main switches.

6. The DCS two-layer network system of a nuclear power plant according to claim 5, wherein, The monitoring ring network subsystem is a single-ring network system, and in the single-ring network system, the number of the main switches is four. Moreover, two of the main switches are the main switches of column A and are arranged in the network cabinets in area A of the safety plant; the other two main switches are the main switches of column B and are arranged in the network cabinets in area B of the safety plant. The number of the first sub-switches is four. Moreover, two of the first sub-switches are the first sub-switches of column A and are correspondingly connected to the two operator workstations of column A one by one; the other two first sub-switches are the first sub-switches of column B and are correspondingly connected to the two operator workstations of column B one by one. The number of the second sub-switches is three. Moreover, two of the second sub-switches are the second sub-switches of column A and are correspondingly connected to the two simplified operator workstations of column A one by one; the other second sub-switch is the second sub-switch of column B and is correspondingly connected to one simplified operator workstation of column B. The number of the third sub-switches is two, and they are respectively the third sub-switches of column A and column B. The number of the fourth sub-switches is two, and they are respectively the fourth sub-switches of column A and column B.

7. The DCS two-layer network system of a nuclear power plant according to claim 6, wherein, One of the main switches in column A and one of the main switches in column B both include at least five optical fiber interfaces. Among them, two of the optical fiber interfaces of one of the main switches in column A form a sub-ring through the second sub-switch in column A, the third optical fiber interface of one of the main switches in column A is connected to the other main switch in column A, the fourth optical fiber interface of one of the main switches in column A is connected to the third sub-switch in column A, and the fifth optical fiber interface of one of the main switches in column A is connected to the fourth sub-switch in column A. two of the optical fiber interfaces of one of the main switches in column B form a sub-ring through the second sub-switch in column B, the third optical fiber interface of one of the main switches in column B is connected to the other main switch in column B, the fourth optical fiber interface of one of the main switches in column B is connected to the third sub-switch in column B, and the fifth optical fiber interface of one of the main switches in column B is connected to the fourth sub-switch in column B.

8. The DCS two-layer network system of a nuclear power plant according to claim 6, characterized in that One of the main switches in Column A and one of the main switches in Column B each include at least five optical fiber interfaces. Among them, Two of the optical fiber interfaces of one of the main switches in Column A form a sub-ring through the first sub-switch in Column A. The third optical fiber interface of one of the main switches in Column A is connected to another main switch in Column A. The fourth optical fiber interface of one of the main switches in Column A is connected to the third sub-switch in Column A. The fifth optical fiber interface of one of the main switches in Column A is connected to the fourth sub-switch in Column A; Two of the optical fiber interfaces of one of the main switches in Column B form a sub-ring through the first sub-switch in Column B. The third optical fiber interface of one of the main switches in Column B is connected to another main switch in Column B. The fourth optical fiber interface of one of the main switches in Column B is connected to the third sub-switch in Column B. The fifth optical fiber interface of one of the main switches in Column B is connected to the fourth sub-switch in Column B.

9. The DCS two-layer network system of a nuclear power plant according to claim 5, wherein The monitored ring network subsystem is a dual-ring network system, and the dual-ring network system includes two single-ring network systems with redundant configurations.

10. The DCS two-layer network system of a nuclear power plant according to claim 1, characterized in that, The monitored ring network subsystem is a ring network subsystem formed based on the Ethernet ring network protection switching protocol.

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