An automatic isolation system for the pressure boundary of the main control room

Abstract

The present invention relates to an automatic isolation system for the pressure boundary of a main control room. By setting a UPS switchboard, when an SBO condition occurs, the 220V power supply provided by the 2h UPS switchboard ensures that when the AC power provided by the 380V emergency switchboard is switched to the SBO power supply, the electric isolation valve remains in a conducting state, so as to solve the problem that the series-type electric isolation valves on the shared fresh air pipeline cannot be opened at the same time under the SBO condition, and avoid the failure of normal supply of fresh air, which affects the habitability of the main control room. By setting a detector interlocked with the isolation valve and the exhaust fan at the normal fresh air intake, the automatic static isolation function of the pressure boundary of the main control room can be realized when a fire occurs outdoors or toxic gas is released. The automatic isolation system for the pressure boundary of the main control room disclosed by the present invention can ensure the habitability of the main control room, improve the reliability of the system design, and ensure the safe and efficient operation of the nuclear power plant.

Description

Technical Field

[0001] The invention belongs to the field of nuclear energy safety control, and in particular relates to an automatic isolation system for the pressure boundary of a main control room. Background Art

[0002] The applicant had installed series electric isolation valves on the normal fresh air duct and exhaust duct at the pressure boundary of the main control room through the main control room air conditioning system, that is, mechanical redundancy was adopted, and the power supply method adopted A and B column distribution. The emergency power supply was equipped with emergency diesel power supply and SBO diesel power supply, which were also set in A and B columns to ensure electrical redundancy and mechanical redundancy functions and meet the single failure criterion. However, this solution has the following problems:

[0003] Since there is a time gap between the switching of normal power supply and emergency diesel engine power supply or SBO diesel engine power supply, and the A and B column power loads cannot be started at the same time when the emergency diesel engine power supply is switched to the SBO diesel engine power supply, and according to the principle of no intervention in the first 30 minutes under SBO working conditions, the series electric isolation valves on the normal fresh air pipeline cannot be started at the same time. That is, under SBO working conditions (when there is no pollution outdoors), the fresh air pipeline under normal working conditions is in a closed state, and according to the interlocking control requirements, the exhaust fan interlocks and stops operating, and the air conditioning system in the main control room loses normal fresh air, which does not meet the design requirements and affects the habitability function of the main control room.

[0004] Moreover, when a fire or toxic gas leak occurs outside, the normal fresh air inlet and exhaust outlet at the pressure boundary of the main control room cannot be isolated in a timely and effective manner. Summary of the invention

[0005] In view of the defects existing in the background technology, the purpose of the present invention is to provide an automatic isolation system for the pressure boundary of the main control room, which can improve the integrity of the pressure boundary of the main control room, improve the reliability of the system design, and improve the safety of nuclear power plant operation.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: an automatic isolation system for the pressure boundary of the main control room, a normal fresh air pipeline and an exhaust air pipeline are arranged at the pressure boundary of the main control room, at least two isolation valves are arranged in series on the normal fresh air pipeline and the exhaust air pipeline, the isolation valve on the exhaust air pipeline is connected in series with the exhaust fan, the isolation valve is powered by the power control part, the power control part includes a 380V normal distribution board, an electric control box, an SBO distribution board, a 220VUPS distribution board and a DCS cabinet, and the DCS cabinet controls the power conversion module inside the electric control box to complete the switching function of the 220V UPS power supply and the SBO power supply.

[0007] Furthermore, the isolation valve is a quick-closing electric isolation valve, which realizes the quick closing and automatic isolation function of the electric isolation valve when power is off through the energy storage of the spring coil.

[0008] Furthermore, the series-type electric isolation valve is powered by the A and B columns respectively.

[0009] Furthermore, the motor power supply and control power supply of the quick-closing electric isolation valve are supplied separately.

[0010] Furthermore, the control power supply of the quick-closing electric isolation valve mainly includes a 380V motor power supply and a 220V control power supply. The motor power supply is powered by the 380V normal distribution board, and the control power supply adopts an independent power supply mode. Under the SBO diesel engine power supply condition, it is powered by a 220V UPS distribution board.

[0011] Furthermore, a detector is provided at the normal fresh air intake port, and the detector is interlocked with the quick-closing electric isolation valve and the exhaust fan.

[0012] Furthermore, the detector includes a smoke sensor and a toxic gas sensor, which are used to detect outdoor smoke concentration signals and toxic gas concentration signals at normal fresh air outlets.

[0013] The effect of the present invention is that: by using the automatic isolation system for the pressure boundary of the main control room disclosed in the present invention, by setting a 2h UPS switchboard, when the SBO condition occurs, the 220V power supply provided by the 2h UPS switchboard ensures that when the AC power provided by the 380V emergency switchboard is switched to the SBO power supply, the electric isolation valve remains in the on state, so as to solve the problem that the series-type electric isolation valves on the shared fresh air pipeline cannot be opened at the same time under the SBO condition, and avoid the normal supply of fresh air, which affects the habitability of the main control room. By setting a detector interlocked with the isolation valve and the exhaust fan at the normal fresh air intake, the automatic static isolation function of the pressure boundary of the main control room can be realized when a fire occurs outdoors or toxic gas is released, so as to ensure the habitability of the main control room and improve the safety of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic structural diagram of an automatic isolation system for the pressure boundary of a main control room shown in the first embodiment of the present invention;

[0015] Figure 2 for Figure 1 Schematic diagram of control method of the system described in;

[0016] Among them: 1-electric isolation valve, 2-electric isolation valve, 3-detector, 4-main control room pressure boundary, 5-electric isolation valve, 6-electric isolation valve, 7-exhaust fan, 11-380V normal distribution board, 12-SBO distribution board, 13-220V UPS distribution board, 14-DCS cabinet, 15-power conversion module, 16-electric control box. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0018] Embodiment 1

[0019] like Figure 1 As shown, this embodiment provides an automatic isolation system for the pressure boundary of the main control room, a normal fresh air pipeline and an exhaust air pipeline are set at the pressure boundary 4 of the main control room, and at least two electric isolation valves are set in series on the normal fresh air pipeline and the exhaust air pipeline. The two electric isolation valves are fast-closing electric isolation valves. In this embodiment, the two electric isolation valves set in series on the normal fresh air pipeline are electric isolation valve 1 and electric isolation valve 2, and the two electric isolation valves set in series on the exhaust air pipeline are electric isolation valve 5 and electric isolation valve 6.

[0020] The quick-closing electric isolation valves 1, 2, 5 and 6 store energy through spring coils to achieve the functions of quick closing and automatic isolation when power is off.

[0021] A detector 3 is set at the normal fresh air intake to detect the outdoor smoke concentration signal and toxic gas concentration signal of the normal fresh air outlet. The electric isolation valves 5 and 6 on the exhaust pipeline are connected in series with the exhaust fan 7. The detector 3 prevents outdoor smoke or toxic gas from entering the habitable area of ​​the main control room through the fresh air pipeline by interlocking the fast-closing electric isolation valves 1 and 2, and the closing signal of the fast-closing electric isolation valves 1 and 2 interlocks and closes the exhaust fan 7 to prevent the main control room from being drawn into negative pressure, thereby timely and effectively ensuring the habitable function of the main control room.

[0022] like Figure 2 As shown, the power control part of the main control room pressure boundary automatic isolation system includes a 380V normal distribution board 11, an electric control box 16, an SBO distribution board 12, a 220V UPS distribution board 13 and a DCS cabinet 14.

[0023] The fast-closing electric isolation valve is powered by the normal power supply and the emergency diesel engine power supply (including the SBO diesel engine power supply), and the two series valves are powered by columns A and B respectively, meeting the single fault criterion.

[0024] The control power supply of the electric isolation valves 1, 2, 5 and 6 mainly includes 380V motor power supply and 220V control power supply.

[0025] The motor power supply of the electric isolation valve, i.e. the main power supply, adopts the normal power distribution method, including the emergency power supply (emergency diesel engine power supply and SBO diesel engine power supply).

[0026] The control power supply of the electric isolation valve, i.e. the brake, adopts an independent power supply mode. Under the SBO diesel engine power supply condition, its power supply level is higher than the normal power supply, that is, it is equipped with a nuclear-grade uninterruptible power supply (UPS).

[0027] In order to solve the problem that the A and B column power supplies cannot be loaded at the same time when the power supply of the electric isolation valves in series on the same fresh air duct is switched to the SBO diesel engine, a nuclear-grade 220V UPS power supply is set as the control power supply for the spring coil under the SBO condition, that is, the main power supply of the fast-closing electric isolation valve, i.e. the motor power supply and the control power supply (brake power supply) are powered separately, and the highest priority of the control power supply under the SBO condition is maintained, that is, the two series valves can be in the open state at the same time under the SBO condition. When there is no pollution outdoors, the habitability function of the main control room is guaranteed, and the reliability of the design of the air-conditioning system in the main control room is improved.

[0028] The specific implementation method is as follows: the power control part provides power to the fast-closing electric isolation valve, including the 380V valve opening power provided by the SBO switchboard 12, and the 220V valve closing power provided by the 220V UPS switchboard 13. At the same time, the DCS cabinet 14 controls the power conversion module 15 contained in the electric control box 16 to complete the switching function of the 220V UPS power supply and the SBO power supply. When the SBO condition occurs, the 220V power supply provided by the 2h UPS switchboard 13 ensures that when the AC power provided by the 380V emergency switchboard 11 is switched to the SBO power supply, the power is cut off. Figure 1 The electric isolation valves 1 and 2 remain in the on state and switch to the SBO power supply after the SBO power supply is successfully loaded. When the control power supply 2h UPS switches to the SBO power supply, the fast-closing electric isolation valve will be short-term power off (about 2s). After the SBO power supply is successfully switched, the valve can be manually opened at the DCS cabinet 14 control terminal according to the working conditions.

[0029] pass Figure 2 The power control part disclosed in the document can ensure that under SBO conditions (when no pollution occurs outdoors), the electric isolation valves on the fresh air duct of the main control room air-conditioning system can be opened at the same time, and can be powered off and closed when the whole plant is powered off, ensuring the habitability and static isolation functions of the main control room and improving the safety of the nuclear power plant.

[0030] At the same time, the present invention is also applicable to other fast-closing electric isolation valve devices on the same type of ventilation pipelines that meet the single failure criterion.

[0031] It can be seen from the above embodiments that the automatic isolation system for the pressure boundary of the main control room disclosed by the present invention, by setting a 2h UPS switchboard, when the SBO condition occurs, the 220V power supply provided by the 2h UPS switchboard ensures that when the AC power provided by the 380V emergency switchboard is switched to the SBO power supply, the electric isolation valve remains in the on state, so as to solve the problem that the series-type electric isolation valves on the shared fresh air pipeline cannot be opened at the same time under the SBO condition, and avoid the normal supply of fresh air, which affects the habitability of the main control room. By setting a detector interlocked with the isolation valve and the exhaust fan at the normal fresh air intake, the automatic static isolation function of the pressure boundary of the main control room can be realized when a fire occurs outdoors or toxic gas is released, ensuring the habitability of the main control room and improving the safety of the nuclear power plant.

[0032] The system described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the technical innovation scope of the present invention.

Claims

1. An automatic isolation system for the pressure boundary of a main control room, characterized in that: A normal fresh air pipeline and an exhaust air pipeline are arranged at the pressure boundary of the main control room. At least two isolation valves are arranged in series on the normal fresh air pipeline and the exhaust air pipeline. The isolation valve on the exhaust air pipeline is connected in series with the exhaust fan. The isolation valve is powered by a power control part. The power control part includes a 380V normal distribution board, an electric control box, an SBO distribution board, a 220V UPS distribution board and a DCS cabinet. The isolation valve is a fast-closing electric isolation valve. The motor power supply and the control power supply of the isolation valve are powered separately. The control power supply is powered by a 220V UPS distribution board to ensure that the two series isolation valves can be in an open state at the same time under the SBO working condition. The control power supply of the isolation valve mainly includes a 380V motor power supply and a 220V control power supply. The motor power supply is powered by the 380V normal distribution board. The control power supply adopts an independent power supply mode. Under the SBO diesel engine power supply working condition, it is powered by a 220V UPS distribution board; the DCS cabinet controls the power conversion module inside the electric control box to complete the 220V The switching function of UPS power supply and SBO power supply; a detector is set at the normal fresh air intake port, and the detector interlocks the isolation valve and the exhaust fan to realize the automatic static isolation function of the pressure boundary of the main control room when a fire occurs outdoors or toxic gas is released.

2. The automatic isolation system for the pressure boundary of the main control room according to claim 1, characterized in that: The isolation valve stores energy through the spring coil to achieve the functions of rapid closing of the isolation valve and automatic isolation when power is off.

3. The automatic isolation system for the pressure boundary of the main control room according to claim 2 is characterized in that: The isolation valve is a series-type electric isolation valve, and the isolation valve is powered by A and B column power supply modes respectively.

4. The automatic isolation system for the pressure boundary of the main control room according to claim 1 is characterized in that: The detector comprises a smoke sensor and a toxic gas sensor, which are used to detect outdoor smoke concentration signals and toxic gas concentration signals at normal fresh air outlets.

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