Nuclear power station containment vessel ventilation control method and system
阅读说明：本技术 核电站安全壳通风控制方法及系统 (Nuclear power station containment vessel ventilation control method and system ) 是由 王远国 郑明辉 荀明磊 黄立 于 2019-09-25 设计创作，主要内容包括：本发明涉及核电站核岛通风空调系统技术领域,公开了一种核电站安全壳通风控制方法及系统,其方法包括：在第一时刻,开启DVW系统中应急管线上的备用排风机；在第二时刻,开启EBA系统的排风隔离风门以及送风隔离风门；在第三时刻,开启DVN排风机,并在第三时刻之后的第一指定时长内,开启DVN系统中的DVN送风机；在第四时刻,开启EBA系统的送风调节挡板；当DVN送风机运行第二指定时长,关闭备用排风机。本发明提供的核电站安全壳通风控制方法,通过控制DVW系统、EBA系统、DVN系统中各设备的启动次序,成功地解决了因EBA-EBR投入运行时对DVN系统产生系统风量扰动,进而影响DVW系统的主管线流量的问题。(The invention relates to the technical field of nuclear power station nuclear island ventilation air-conditioning systems, and discloses a method and a system for controlling the ventilation of a containment vessel of a nuclear power station, wherein the method comprises the following steps: starting a standby exhaust fan on an emergency pipeline in the DVW system at a first moment; at the second moment, an exhaust isolation air door and an air supply isolation air door of the EBA system are opened; starting a DVN exhaust fan at a third moment, and starting a DVN blower in the DVN system within a first specified time length after the third moment; at the fourth moment, opening an air supply adjusting baffle of the EBA system; and when the DVN blower operates for a second designated time, closing the standby exhaust fan. According to the ventilation control method for the containment of the nuclear power station, provided by the invention, the problem that the main pipeline flow of the DVW system is influenced due to the system air volume disturbance generated on the DVN system when the EBA-EBR is put into operation is successfully solved by controlling the starting sequence of each device in the DVW system, the EBA system and the DVN system.)
1. A nuclear power station containment ventilation control method is characterized by being applied to a nuclear power station containment ventilation control system, wherein the nuclear power station containment ventilation control system comprises a DVW system, a DVN system and an EBA system;
the DVW system is used for providing exhaust air for a gallery surrounding area of a containment building;
the DVN system is used for providing ventilation for a nuclear auxiliary plant, and the nuclear auxiliary plant is communicated with an annular gallery area of the reactor containment plant; the system is also used for providing ventilation and air exhaust for the EBA system;
the EBA system is used for providing ventilation and exhaust for the containment vessel of the nuclear power station;
the ventilation control method for the containment vessel of the nuclear power station comprises the following steps:
turning on a backup exhaust fan on an emergency pipeline in the DVW system at a first time to improve readings of an air flow metering device disposed in the annulus region;
at a second moment, opening an exhaust isolation air door and an air supply isolation air door of the EBA system to enable the EBA system to be communicated with the DVN system, wherein the exhaust isolation air door is arranged between the containment vessel of the nuclear power station and a DVN exhaust fan in the DVN system, and the air supply isolation air door is arranged between the containment vessel of the nuclear power station and a DVN air feeder in the DVN system;
starting the DVN exhaust fan at a third moment, and starting a DVN blower in the DVN system within a first designated time after the third moment to start the DVN system so that the DVN system provides ventilation and exhaust for the EBA system;
at a fourth moment, opening an air supply adjusting baffle of the EBA system to adjust the air volume entering the EBA system, wherein the air supply adjusting baffle is arranged between the containment vessel of the nuclear power station and a DVN blower in the DVN system;
and when the DVN air blower operates for a second designated time, closing the standby exhaust fan.
2. The nuclear power plant containment ventilation control method of claim 1, wherein the DVW system includes a main line disposed in the annulus area, the emergency line and a utility line connected to the main line;
when the standby exhaust fan is started, airflow flows through the main pipeline and respectively enters the emergency pipeline and the common pipeline.
3. The nuclear power plant containment ventilation control method of claim 2, wherein the emergency pipeline is provided with an emergency pre-filter, an emergency high efficiency filter, an iodine adsorber, a main emergency ventilator and the standby ventilator, wherein the main emergency ventilator and the standby ventilator are arranged in parallel;
the common pipeline is provided with a pre-filter, a high-efficiency filter and a common exhaust fan.
4. The nuclear power plant containment ventilation control method of claim 2, wherein when a specified condition occurs, the emergency line is opened while the utility line is closed;
the specified conditions include at least one of:
a loss of coolant accident occurs;
iodine contamination occurs;
emergency situations arise with the usual pipelines.
5. The nuclear power plant containment ventilation control method of claim 1, wherein the opening of the exhaust isolation damper and the supply isolation damper of the EBA system comprises:
opening an exhaust isolation air door of the EBA system, wherein the exhaust isolation air door comprises an in-shell exhaust isolation air door arranged in the containment vessel of the nuclear power station and an out-shell exhaust isolation air door arranged outside the containment vessel of the nuclear power station;
and opening the air supply isolation air door of the EBA system, wherein the air supply isolation air door comprises an air supply isolation air door arranged in a shell in the containment of the nuclear power station and an air supply isolation air door arranged outside the shell outside the containment of the nuclear power station.
6. The nuclear power plant containment ventilation control method of claim 1, wherein the DVN system includes a supply air line and an exhaust air line;
the air supply pipeline is provided with the DVN air blower and a DVN adjusting baffle plate for adjusting the output air volume of the DVN air blower;
the air exhaust pipeline comprises a normal air exhaust pipeline and an abnormal air exhaust pipeline, the DVN exhaust fan is arranged on the normal air exhaust pipeline, and the abnormal air exhaust pipeline is provided with a DVN iodine filter and a DVN iodine exhaust fan;
the air supply pipeline is connected with an air supply isolation air door of the EBA system, and when the air supply isolation air door is opened, air flow flows into the EBA system from the air supply pipeline through the air supply isolation air door;
the exhaust pipeline is connected with an exhaust isolation air door of the EBA system, and when the exhaust isolation air door is opened, airflow flows out of the EBA system from the exhaust isolation air door through the exhaust pipeline.
7. The nuclear power plant containment ventilation control method of claim 1, wherein the first specified length of time comprises 25 seconds.
8. A ventilation control system for a containment vessel of a nuclear power station is characterized by comprising a DVW system, a DVN system and an EBA system;
the DVW system is used for providing exhaust air for a gallery surrounding area of a containment building;
the DVN system is used for providing ventilation for a nuclear auxiliary plant, and the nuclear auxiliary plant is communicated with an annular gallery area of the reactor containment plant; the system is also used for providing ventilation and air exhaust for the EBA system;
the EBA system is used for providing ventilation and exhaust for the containment vessel of the nuclear power station;
the nuclear power station containment ventilation control system further comprises a plurality of control units, the control units are used for controlling the operation state of the specified equipment, and the control units comprise:
the first control unit is used for starting a standby exhaust fan on an emergency pipeline in the DVW system at a first moment so as to improve the reading of an air flow metering device arranged in the annular corridor area;
the second control unit is used for opening an exhaust isolation air door and an air supply isolation air door of the EBA system at a second moment so as to enable the EBA system to be communicated with the DVN system, the exhaust isolation air door is arranged between the containment vessel of the nuclear power station and a DVN exhaust fan in the DVN system, and the air supply isolation air door is arranged between the containment vessel of the nuclear power station and the DVN air feeder in the DVN system;
a third control unit, configured to turn on the DVN exhaust blower at a third time, and turn on the DVN blower in the DVN system within a first specified time period after the third time, so as to start the DVN system, so that the DVN system provides ventilation and exhaust to the EBA system;
the fourth control unit is used for opening an air supply adjusting baffle of the EBA system at a fourth moment so as to adjust the air volume entering the EBA system, and the air supply adjusting baffle is arranged between the containment vessel of the nuclear power station and a DVN blower in the DVN system;
and the fifth control unit is used for closing the standby exhaust fan when the DVN blower operates for a second specified time.
9. The nuclear power plant containment ventilation control system of claim 8, wherein the DVW system includes a main line disposed in the annulus area, the emergency line and a utility line connected to the main line;
when the standby exhaust fan is started, airflow flows through the main pipeline and respectively enters the emergency pipeline and the common pipeline.
10. The nuclear power plant containment ventilation control system of claim 9, wherein the emergency pipeline is provided with an emergency pre-filter, an emergency high efficiency filter, an iodine adsorber, a main emergency ventilator, and the back-up ventilator, wherein the main emergency ventilator is arranged in parallel with the back-up ventilator;
the common pipeline is provided with a pre-filter, a high-efficiency filter and a common exhaust fan.
11. The nuclear power plant containment ventilation control system of claim 9, wherein the control unit further comprises:
the emergency processing unit is used for opening the emergency pipeline and closing the common pipeline at the same time when a specified condition occurs;
the specified conditions include at least one of:
a loss of coolant accident occurs;
iodine contamination occurs;
emergency situations arise with the usual pipelines.
12. The nuclear power plant containment ventilation control system of claim 8, wherein the third control unit comprises:
the method comprises the steps that an exhaust air door unit is opened and used for opening an exhaust isolation air door of the EBA system, wherein the exhaust isolation air door comprises an in-shell exhaust isolation air door arranged in a containment vessel of the nuclear power station and an out-shell exhaust isolation air door arranged outside the containment vessel of the nuclear power station;
and opening an air supply air door unit for opening an air supply isolation air door of the EBA system, wherein the air supply isolation air door comprises an air supply isolation air door arranged in a shell in the containment of the nuclear power station and an air supply isolation air door arranged outside the shell outside the containment of the nuclear power station.
13. The nuclear power plant containment ventilation control system of claim 8, wherein the DVN system includes a supply air line and an exhaust air line;
the air supply pipeline is provided with the DVN air blower and a DVN adjusting baffle plate for adjusting the output air volume of the DVN air blower;
the air exhaust pipeline comprises a normal air exhaust pipeline and an abnormal air exhaust pipeline, the DVN exhaust fan is arranged on the normal air exhaust pipeline, and the abnormal air exhaust pipeline is provided with a DVN iodine filter and a DVN iodine exhaust fan;
the air supply pipeline is connected with an air supply isolation air door of the EBA system, and when the air supply isolation air door is opened, air flow flows into the EBA system from the air supply pipeline through the air supply isolation air door;
the exhaust pipeline is connected with an exhaust isolation air door of the EBA system, and when the exhaust isolation air door is opened, airflow flows out of the EBA system from the exhaust isolation air door through the exhaust pipeline.
14. The nuclear power plant containment ventilation control system of claim 8, wherein the first specified length of time comprises 25 seconds.
Technical Field
The invention belongs to the technical field of nuclear power station nuclear island ventilation air-conditioning systems, and particularly relates to a method and a system for controlling ventilation of a containment vessel of a nuclear power station.
Background
In the production and operation process of a nuclear power plant, good ventilation of a containment building and the surrounding area of the containment building must be guaranteed. The existing ventilation system related to the containment building is composed of a plurality of ventilation systems which are independently operated, such as a DVW system (containment ring corridor room ventilation system), an EBA system (containment ventilation system) and a DVN system (nuclear auxiliary building ventilation system). Each ventilation system must be strictly executed according to the operating steps established by the nuclear power plant operating specifications.
However, when the DVW system is started according to the existing nuclear power plant operation specification, the air flow monitoring device on the DVW main pipeline often sends an alarm signal, further causing the centralized data processing system to generate an abnormal signal, so that the unit generates a random first group I0 (the nuclear safety equipment is not available), and the random IO consumption ratio (the ratio of the time actually consumed by the fault maintenance to the withdrawal time specified by the corresponding I0 clause) is increased.
Disclosure of Invention
The invention aims to provide a ventilation control method for a containment vessel of a nuclear power station, which aims to solve the problem that an alarm signal occurs when a DVW system is started in the prior art.
In order to achieve the purpose, the invention adopts the technical scheme that: the method is applied to a containment ventilation control system of the nuclear power station, and the containment ventilation control system of the nuclear power station comprises a DVW system, a DVN system and an EBA system;
the DVW system is used for providing exhaust air for a gallery surrounding area of a containment building;
the DVN system is used for providing ventilation for a nuclear auxiliary plant, and the nuclear auxiliary plant is communicated with an annular gallery area of the reactor containment plant; the system is also used for providing ventilation and air exhaust for the EBA system;
the EBA system is used for providing ventilation and exhaust for the containment vessel of the nuclear power station;
the ventilation control method for the containment vessel of the nuclear power station comprises the following steps:
turning on a backup exhaust fan on an emergency pipeline in the DVW system at a first time to improve readings of an air flow metering device disposed in the annulus region;
at a second moment, opening an exhaust isolation air door and an air supply isolation air door of the EBA system to enable the EBA system to be communicated with the DVN system, wherein the exhaust isolation air door is arranged between the containment vessel of the nuclear power station and a DVN exhaust fan in the DVN system, and the air supply isolation air door is arranged between the containment vessel of the nuclear power station and a DVN air feeder in the DVN system;
starting the DVN exhaust fan at a third moment, and starting a DVN blower in the DVN system within a first designated time after the third moment to start the DVN system so that the DVN system provides ventilation and exhaust for the EBA system;
at a fourth moment, opening an air supply adjusting baffle of the EBA system to adjust the air volume entering the EBA system, wherein the air supply adjusting baffle is arranged between the containment vessel of the nuclear power station and a DVN blower in the DVN system;
and when the DVN air blower operates for a second designated time, closing the standby exhaust fan.
Optionally, the DVW system includes a main pipeline disposed in the annulus region, the emergency pipeline connected to the main pipeline, and a common pipeline;
when the standby exhaust fan is started, airflow flows through the main pipeline and respectively enters the emergency pipeline and the common pipeline.
Optionally, the emergency pipeline is provided with an emergency pre-filter, an emergency high-efficiency filter, an iodine adsorber, a main emergency exhaust fan and the standby exhaust fan, wherein the main emergency exhaust fan and the standby exhaust fan are arranged in parallel;
the common pipeline is provided with a pre-filter, a high-efficiency filter and a common exhaust fan.
Optionally, when a specified condition occurs, the emergency pipeline is opened, and the common pipeline is closed;
the specified conditions include at least one of:
a loss of coolant accident occurs;
iodine contamination occurs;
emergency situations arise with the usual pipelines.
Optionally, the opening of the exhaust isolation damper and the air supply isolation damper of the EBA system includes:
opening an exhaust isolation air door of the EBA system, wherein the exhaust isolation air door comprises an in-shell exhaust isolation air door arranged in the containment vessel of the nuclear power station and an out-shell exhaust isolation air door arranged outside the containment vessel of the nuclear power station;
and opening the air supply isolation air door of the EBA system, wherein the air supply isolation air door comprises an air supply isolation air door arranged in a shell in the containment of the nuclear power station and an air supply isolation air door arranged outside the shell outside the containment of the nuclear power station.
Optionally, the DVN system includes an air supply line and an air exhaust line;
the air supply pipeline is provided with the DVN air blower and a DVN adjusting baffle plate for adjusting the output air volume of the DVN air blower;
the air exhaust pipeline comprises a normal air exhaust pipeline and an abnormal air exhaust pipeline, the DVN exhaust fan is arranged on the normal air exhaust pipeline, and the abnormal air exhaust pipeline is provided with a DVN iodine filter and a DVN iodine exhaust fan;
the air supply pipeline is connected with an air supply isolation air door of the EBA system, and when the air supply isolation air door is opened, air flow flows into the EBA system from the air supply pipeline through the air supply isolation air door;
the exhaust pipeline is connected with an exhaust isolation air door of the EBA system, and when the exhaust isolation air door is opened, airflow flows out of the EBA system from the exhaust isolation air door through the exhaust pipeline.
Optionally, the first specified duration comprises 25 seconds.
The invention also provides a ventilation control system for the containment of the nuclear power station, which comprises a DVW system, a DVN system and an EBA system;
the DVW system is used for providing exhaust air for a gallery surrounding area of a containment building;
the DVN system is used for providing ventilation for a nuclear auxiliary plant, and the nuclear auxiliary plant is communicated with an annular gallery area of the reactor containment plant; the system is also used for providing ventilation and air exhaust for the EBA system;
the EBA system is used for providing ventilation and exhaust for the containment vessel of the nuclear power station;
the nuclear power station containment ventilation control system further comprises a plurality of control units, the control units are used for controlling the operation state of the specified equipment, and the control units comprise:
the first control unit is used for starting a standby exhaust fan on an emergency pipeline in the DVW system at a first moment so as to improve the reading of an air flow metering device arranged in the annular corridor area;
the second control unit is used for opening an exhaust isolation air door and an air supply isolation air door of the EBA system at a second moment so as to enable the EBA system to be communicated with the DVN system, the exhaust isolation air door is arranged between the containment vessel of the nuclear power station and a DVN exhaust fan in the DVN system, and the air supply isolation air door is arranged between the containment vessel of the nuclear power station and the DVN air feeder in the DVN system;
a third control unit, configured to turn on the DVN exhaust blower at a third time, and turn on the DVN blower in the DVN system within a first specified time period after the third time, so as to start the DVN system, so that the DVN system provides ventilation and exhaust to the EBA system;
the fourth control unit is used for opening an air supply adjusting baffle of the EBA system at a fourth moment so as to adjust the air volume entering the EBA system, and the air supply adjusting baffle is arranged between the containment vessel of the nuclear power station and a DVN blower in the DVN system;
and the fifth control unit is used for closing the standby exhaust fan when the DVN blower operates for a second specified time.
Optionally, the DVW system includes a main pipeline disposed in the annulus region, the emergency pipeline connected to the main pipeline, and a common pipeline;
when the standby exhaust fan is started, airflow flows through the main pipeline and respectively enters the emergency pipeline and the common pipeline.
Optionally, the emergency pipeline is provided with an emergency pre-filter, an emergency high-efficiency filter, an iodine adsorber, a main emergency exhaust fan and the standby exhaust fan, wherein the main emergency exhaust fan and the standby exhaust fan are arranged in parallel;
the common pipeline is provided with a pre-filter, a high-efficiency filter and a common exhaust fan.
Optionally, the control unit further includes:
the emergency processing unit is used for opening the emergency pipeline and closing the common pipeline at the same time when a specified condition occurs;
the specified conditions include at least one of:
a loss of coolant accident occurs;
iodine contamination occurs;
emergency situations arise with the usual pipelines.
Optionally, the third control unit includes:
the method comprises the steps that an exhaust air door unit is opened and used for opening an exhaust isolation air door of the EBA system, wherein the exhaust isolation air door comprises an in-shell exhaust isolation air door arranged in a containment vessel of the nuclear power station and an out-shell exhaust isolation air door arranged outside the containment vessel of the nuclear power station;
and opening an air supply air door unit for opening an air supply isolation air door of the EBA system, wherein the air supply isolation air door comprises an air supply isolation air door arranged in a shell in the containment of the nuclear power station and an air supply isolation air door arranged outside the shell outside the containment of the nuclear power station.
Optionally, the DVN system includes an air supply line and an air exhaust line;
the air supply pipeline is provided with the DVN air blower and a DVN adjusting baffle plate for adjusting the output air volume of the DVN air blower;
the air exhaust pipeline comprises a normal air exhaust pipeline and an abnormal air exhaust pipeline, the DVN exhaust fan is arranged on the normal air exhaust pipeline, and the abnormal air exhaust pipeline is provided with a DVN iodine filter and a DVN iodine exhaust fan;
the air supply pipeline is connected with an air supply isolation air door of the EBA system, and when the air supply isolation air door is opened, air flow flows into the EBA system from the air supply pipeline through the air supply isolation air door;
the exhaust pipeline is connected with an exhaust isolation air door of the EBA system, and when the exhaust isolation air door is opened, airflow flows out of the EBA system from the exhaust isolation air door through the exhaust pipeline.
Optionally, the first specified duration comprises 25 seconds.
The method for controlling the ventilation of the containment vessel of the nuclear power station has the advantages that: by controlling the starting sequence of each device in the DVW system, the EBA system and the DVN system, the problem that the main pipeline flow of the DVW system is influenced by system air volume disturbance generated to the DVN system when the EBA-EBR is put into operation is successfully solved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a schematic flow chart of a method for controlling ventilation of a containment vessel of a nuclear power plant according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a nuclear power plant containment ventilation control system according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a control unit in a nuclear power plant containment ventilation control system according to an embodiment of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
Referring to fig. 1 and fig. 2 together, a method for controlling ventilation of a containment vessel of a nuclear power plant according to the present invention will now be described. The nuclear power station containment ventilation control method is applied to a nuclear power station containment ventilation control system, wherein the nuclear power station containment ventilation control system comprises a DVW system, a DVN system and an EBA system;
the DVW system is used for providing exhaust air for a gallery surrounding area of a containment building;
the DVN system is used for providing ventilation for a nuclear auxiliary plant, and the nuclear auxiliary plant is communicated with an annular gallery area of the reactor containment plant; the system is also used for providing ventilation and air exhaust for the EBA system;
the EBA system is used for providing ventilation and exhaust for the containment vessel of the nuclear power station;
the ventilation control method for the containment vessel of the nuclear power station comprises the following steps:
turning on a backup exhaust fan on an emergency pipeline in the DVW system at a first time to improve readings of an air flow metering device disposed in the annulus region;
at a second moment, opening an exhaust isolation air door and an air supply isolation air door of the EBA system to enable the EBA system to be communicated with the DVN system, wherein the exhaust isolation air door is arranged between the containment vessel of the nuclear power station and a DVN exhaust fan in the DVN system, and the air supply isolation air door is arranged between the containment vessel of the nuclear power station and a DVN air feeder in the DVN system;
starting the DVN exhaust fan at a third moment, and starting a DVN blower in the DVN system within a first designated time after the third moment to start the DVN system so that the DVN system provides ventilation and exhaust for the EBA system;
at a fourth moment, opening an air supply adjusting baffle of the EBA system to adjust the air volume entering the EBA system, wherein the air supply adjusting baffle is arranged between the containment vessel of the nuclear power station and a DVN blower in the DVN system;
and when the DVN air blower operates for a second designated time, closing the standby exhaust fan.
In this embodiment, the DVW system (containment enclosure environmental corridor room ventilation system) is used to provide ventilation to the environmental corridor area of the containment building. Specifically, the DVW system provides exhaust to all annular gallery areas within the containment building that house the penetrations. The DVW system functions include: the air flow direction is controlled, and air possibly polluted in the room of the ring corridor is prevented from being diffused to the external environment; the second is to ensure the filtration of the air coming from the room of the corridor to reduce the level of radioactivity discharged to the NAB (auxiliary plant) smoke window.
The DVW system is an open ventilation system operated by exhaust air. The volume of air that the DVW system needs to handle includes the volume of air diverted from adjacent areas, as well as the volume of air bled into by outdoor air. The DVW system is used to collect containment penetration leaks. The DVW system runs continuously. All exhaust gas is filtered through a high efficiency filter (not shown). If necessary, an iodine adsorber may be provided to adsorb iodine and iodine-containing contaminants (radioactive materials).
The ventilation ducts are arranged in all the corridors of the room containing the penetrations, set at a level of +11.50 metres. The exhaust fan set is located in an NAB (auxiliary workshop).
In some cases, the DVW system can ensure that the factory floor is not contaminated in the event of a malfunction or accident. Thus, the DVW system also includes a mode for operation after LOCA (loss of Coolant Accident). At this point, the DVW system is operating using an emergency pipeline (i.e., X pipeline, provided with an iodine adsorber).
The function of the EBA system (containment ventilation system) comprises: reducing the temperature in the containment vessel during a cold shut-down to allow service personnel to enter the containment vessel for maintenance; the concentration of gaseous fission products within the containment vessel is reduced to allow permanent access by personnel. During cold shutdown, the dry bulb temperature in the containment vessel is required to be 15-35 ℃, and the air exchange frequency is 1 time/h under the condition of no iodine pollution.
The EBA system is a direct-flow ventilation system and is provided with an air supply pipe and an air exhaust pipe which are respectively connected with an air supply pipeline and an air exhaust pipeline of a DVN system (a nuclear auxiliary factory building ventilation system), and the DVN system provides air supply and air exhaust functions. The EBA system is started and operated after the RRA system (a waste heat discharge system arranged in a containment) has starting conditions (the pressure of a reactor coolant is lower than 3.2Mpa, and the temperature is lower than 177 ℃).
In order to ensure rapid reduction of the containment room temperature in hot weather or in the early stages of a shut down, an EBA-EVR (EVR: continuous Containment Ventilation System, ensuring safe operation of the equipment in the reactor building and safe access to the required room temperature conditions) or EBA-EVC (EVC: reactor pit Ventilation System, for providing ventilation to the pressure vessel and its external components, associated concrete and passageways) combined mode of operation may be used. Under each operation mode, the relevant valve can be correspondingly opened and closed according to actual needs.
The DVN system (nuclear assisted plant ventilation system) is the largest ventilation system in nuclear island ventilation and is used to provide ventilation services to a plurality of nuclear assisted plants (NX). Specifically, the nuclear-assisted plant (NX) is divided into NA, NB, NC, ND, and other areas.
In normal operation of the nuclear power plant, the DVN system may also have the following functions: firstly, a safe and proper indoor environment is provided for a nuclear auxiliary plant and an electric plant, and the health of personnel and the normal operation of equipment are ensured; secondly, controlling the radioactivity level in the indoor air according to the relevant physical grade of health; thirdly, controlling the airflow to flow from a low pollution area to a high pollution area in the factory building, and reducing the radioactive concentration of polluted air to an allowable level before the airflow is discharged to the atmosphere; fourthly, under any operation condition, ensuring slight negative pressure of the whole factory building so as to reduce the outward leakage of the polluted air to the minimum extent as much as possible; and fifthly, providing required ventilation and filtration to the EBA system during shutdown, and performing discharge treatment.
When the EBA operation mode is switched to EBA-EBR combined operation according to a overhaul file (one of nuclear power plant operation specifications), a master control room often has a situation that the main pipeline flow of the DVW system is reported incorrectly, and meanwhile, the flow parameter of the DVW system displayed on the KIT system (centralized data processing system) is also in an abnormal state. Upon inspection, the DVW system was in normal operation with the various devices (each fire damper normally open). And after multiple times of investigation, determining that the alarm occurrence time is close to the input operation time of the EBA-EBR. Therefore, the method can preliminarily determine that the air volume entering the DVW system is lower than a normal value due to the system air volume disturbance generated to the DVN system when the EBA-EBR is put into operation, and further induce the error report of the main pipeline flow of the DVW system. At this point, the master records I01 and notifies master number two. The solution is as follows: and starting a standby air feeder of the DVN system, adjusting a DVN adjusting baffle and improving the air volume output of the started DVN system. And after the air volume output of the starting DVN system is improved, the alarm disappears, and the main control ends I01. However, this solution would result in the crew generating a random first group I0 (nuclear safety equipment not available) increasing the random I0 consumption ratio (random I0 consumption ratio is the ratio of the time actually consumed due to the faulty maintenance to the pullback time specified in the corresponding I0 clause).
Through multiple researches of the inventor, the ventilation control method for the containment vessel of the nuclear power plant provided by the embodiment is found. Through practical verification, the nuclear power station containment ventilation control method provided by the embodiment is found to be used for opening the standby exhaust fan on the emergency pipeline in the DVW system (the reading of the air flow metering device arranged in the corridor area can be improved) before the exhaust isolation air door and the air supply isolation air door of the EBA system are opened, so that the occurrence of error report of the flow of the main pipeline of the DVW system can be effectively prevented, the unit does not generate random I0, and the consumption ratio of random I0 is reduced. The method for controlling ventilation of the containment vessel of the nuclear power station provided by the embodiment successfully solves the problem that the main pipeline flow of the DVW system is influenced by system air volume disturbance generated to the DVN system when the EBA-EBR is put into operation by controlling the starting sequence of each device in the DVW system, the EBA system and the DVN system.
It should be noted that in the method for controlling the ventilation of the containment vessel of the nuclear power plant provided in this embodiment, the terms such as the first time, the second time, and the like are only used to indicate the temporal order, and no other special meaning is implied. And if the DVN system is in the running state, the started DVN exhaust fan is the standby DVN exhaust fan at the third moment. And the second specified time length may depend on the specific situation. After the EBA-EBR is put into operation, the backup exhaust fan can be shut down if the readings from the air flow metering device in the corridor area are stable.
As shown in fig. 2, fig. 2 is a schematic structural diagram provided in an embodiment of a ventilation control system for a containment vessel of a nuclear power plant according to the present invention. Fig. 2 includes 2 sets of ventilation control systems for the containment of the nuclear power plant, which are a number 1 machine containment ventilation control system and a number 2 machine containment ventilation control system, respectively. The number 1 containment ventilation control system and the number 2 containment ventilation control system share the same set of DVN system. Whereas the DVW system and the EBA system are each separately provided.
Optionally, the DVW system includes a main pipeline disposed in the annulus region, the emergency pipeline connected to the main pipeline, and a common pipeline;
when the standby exhaust fan is started, airflow flows through the main pipeline and respectively enters the emergency pipeline and the common pipeline.
In this embodiment, the DVW system includes a main pipeline disposed in the corridor area, an emergency pipeline connected to the main pipeline, and a common pipeline. The main line connects the connection plant (identified as WX in fig. 2), the electrical plant (identified as LX in fig. 2) and the nuclear auxiliary plant.
When the standby exhaust fan is started, airflow flows through the main pipeline, respectively enters the emergency pipeline and the common pipeline, and is finally exhausted through the exhaust chimney.
In this embodiment, each device of the DVW system may be arranged with reference to the schematic structural diagram of the nuclear power plant containment ventilation control system provided in fig. 2. And will not be described in detail herein.
Optionally, the emergency pipeline is provided with an emergency pre-filter, an emergency high-efficiency filter, an iodine adsorber, a main emergency exhaust fan and the standby exhaust fan, wherein the main emergency exhaust fan and the standby exhaust fan are arranged in parallel;
the common pipeline is provided with a pre-filter, a high-efficiency filter and a common exhaust fan.
In this embodiment, the DVW system is normally operated continuously. The DVW system can be provided with two pipelines which are connected in parallel and are connected with a main pipeline and an NAB smoke window, wherein the two pipelines are a common pipeline and an emergency pipeline respectively. The NAB smoke window is used for discharging waste gas generated by the containment vessel of the nuclear power plant and treated. In non-emergency situations, the DVW system uses conventional piping to treat the exhaust gases generated by the nuclear power plant containment. The conventional pipeline may be configured with a pre-filter, a high efficiency filter and a main emergency exhaust fan. A common pipeline, referred to as a Y pipeline in some scenarios.
In an emergency situation, the DVW system uses an emergency line to treat the exhaust generated by the nuclear power plant containment. The emergency pipeline may be configured with a pre-filter, a high efficiency filter, an iodine adsorber, an emergency operation exhaust fan and a back-up exhaust fan. An emergency pipeline, in some scenarios referred to as an X-pipeline.
The emergency pipeline is provided with a spare exhaust fan and an iodine adsorber compared with the common pipeline, so that the emergency pipeline can process larger air flow and gas with higher pollution concentration.
Optionally, when a specified condition occurs, the emergency pipeline is opened, and the common pipeline is closed;
the specified conditions include at least one of:
a loss of coolant accident occurs;
iodine contamination occurs;
emergency situations arise with the usual pipelines.
In this embodiment, the emergency pipeline needs to be enabled when a specified condition occurs. The specified conditions include: a loss of coolant accident occurs; iodine contamination occurs; emergency situations arise with the usual pipelines.
The DVW system is operated by a control room and switches the operation mode according to an actual operation condition. It should be noted that in each room where a penetration is provided, it is necessary to ensure that the direction of the airflow is consistent with the DVW system to ensure the filtering effect on the room. Thus, the individual rooms need to be closed to a sufficient density, but at the same time there also needs to be air inlets or air slots allowing air to enter. If a room cannot be closed, a leak collection box is used to vent air on each penetration.
Optionally, the opening of the exhaust isolation damper and the air supply isolation damper of the EBA system includes:
opening an exhaust isolation air door of the EBA system, wherein the exhaust isolation air door comprises an in-shell exhaust isolation air door arranged in the containment vessel of the nuclear power station and an out-shell exhaust isolation air door arranged outside the containment vessel of the nuclear power station;
and opening the air supply isolation air door of the EBA system, wherein the air supply isolation air door comprises an air supply isolation air door arranged in a shell in the containment of the nuclear power station and an air supply isolation air door arranged outside the shell outside the containment of the nuclear power station.
In this embodiment, the EBA system is including setting up in the isolation air door of airing exhaust of exhaust pipe and setting up in the air supply isolation air door of blast pipe. In order to improve the safety of containment exhaust, the exhaust isolation air door comprises an in-shell exhaust isolation air door arranged in the containment of the nuclear power station and an out-shell exhaust isolation air door arranged outside the containment of the nuclear power station; the air supply isolation air door comprises an air supply isolation air door arranged in a shell in the containment vessel of the nuclear power station and an air supply isolation air door arranged outside the shell outside the containment vessel of the nuclear power station.
Optionally, the DVN system includes an air supply line and an air exhaust line;
the air supply pipeline is provided with the DVN air blower and a DVN adjusting baffle plate for adjusting the output air volume of the DVN air blower;
the air exhaust pipeline comprises a normal air exhaust pipeline and an abnormal air exhaust pipeline, the DVN exhaust fan is arranged on the normal air exhaust pipeline, and the abnormal air exhaust pipeline is provided with a DVN iodine filter and a DVN iodine exhaust fan;
the air supply pipeline is connected with an air supply isolation air door of the EBA system, and when the air supply isolation air door is opened, air flow flows into the EBA system from the air supply pipeline through the air supply isolation air door;
the exhaust pipeline is connected with an exhaust isolation air door of the EBA system, and when the exhaust isolation air door is opened, airflow flows out of the EBA system from the exhaust isolation air door through the exhaust pipeline.
In this embodiment, the DVN system includes an air supply line and an air exhaust line. The air supply pipeline is provided with a DVN air blower and a DVN adjusting baffle plate for adjusting the output air volume of the DVN air blower. When the DVN system is in normal operation, two DVN air blowers operate, and the other DVN air blower is kept for standby.
The air exhaust pipeline comprises a normal air exhaust pipeline and an abnormal air exhaust pipeline, the DVN exhaust fan is arranged on the normal air exhaust pipeline, and the abnormal air exhaust pipeline is provided with the DVN iodine filter and the DVN iodine exhaust fan. The air supply pipeline is connected with an air supply isolation air door of the EBA system, and when the air supply isolation air door is opened, air flow flows into the EBA system from the air supply pipeline through the air supply isolation air door. The air exhaust pipeline is connected with an air exhaust isolation air door of the EBA system, and when the air exhaust isolation air door is opened, air flow flows out of the EBA system from the air exhaust isolation air door through the air exhaust pipeline. When the DVN system normally operates, the normal air exhaust pipeline is provided with two DVN exhaust fans for operation, and the other DVN exhaust fan is kept for standby. The abnormal air exhaust pipeline is provided with a DVN iodine filter and a DVN iodine exhaust fan so as to supply emergency use.
Optionally, the first specified duration comprises 25 seconds.
In this embodiment, after the DVN exhaust fan is started, the DVN blower should be started within 25 seconds as much as possible to prevent the excessive negative pressure from causing the low air volume alarm of the DVW system. In some cases, the time of the first specified duration may also be determined based on actual circumstances.
As shown in fig. 3, an embodiment of the present invention further provides a nuclear power plant containment ventilation control system, which includes a DVW system, a DVN system, and an EBA system;
the DVW system is used for providing exhaust air for a gallery surrounding area of a containment building;
the DVN system is used for providing ventilation for a nuclear auxiliary plant, and the nuclear auxiliary plant is communicated with an annular gallery area of the reactor containment plant; the system is also used for providing ventilation and air exhaust for the EBA system;
the EBA system is used for providing ventilation and exhaust for the containment vessel of the nuclear power station;
the nuclear power station containment ventilation control system further comprises a plurality of control units, the control units are used for controlling the operation state of the specified equipment, and the control units comprise:
a
the
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a
Optionally, the DVW system includes a main pipeline disposed in the annulus region, the emergency pipeline connected to the main pipeline, and a common pipeline;
when the standby exhaust fan is started, airflow flows through the main pipeline and respectively enters the emergency pipeline and the common pipeline.
Optionally, the emergency pipeline is provided with an emergency pre-filter, an emergency high-efficiency filter, an iodine adsorber, a main emergency exhaust fan and the standby exhaust fan, wherein the main emergency exhaust fan and the standby exhaust fan are arranged in parallel;
the common pipeline is provided with a pre-filter, a high-efficiency filter and a common exhaust fan.
Optionally, the control unit further includes:
the emergency processing unit is used for opening the emergency pipeline and closing the common pipeline at the same time when a specified condition occurs;
the specified conditions include at least one of:
a loss of coolant accident occurs;
iodine contamination occurs;
emergency situations arise with the usual pipelines.
Optionally, the
the method comprises the steps that an exhaust air door unit is opened and used for opening an exhaust isolation air door of the EBA system, wherein the exhaust isolation air door comprises an in-shell exhaust isolation air door arranged in a containment vessel of the nuclear power station and an out-shell exhaust isolation air door arranged outside the containment vessel of the nuclear power station;
and opening an air supply air door unit for opening an air supply isolation air door of the EBA system, wherein the air supply isolation air door comprises an air supply isolation air door arranged in a shell in the containment of the nuclear power station and an air supply isolation air door arranged outside the shell outside the containment of the nuclear power station.
Optionally, the DVN system includes an air supply line and an air exhaust line;
the air supply pipeline is provided with the DVN air blower and a DVN adjusting baffle plate for adjusting the output air volume of the DVN air blower;
the air exhaust pipeline comprises a normal air exhaust pipeline and an abnormal air exhaust pipeline, the DVN exhaust fan is arranged on the normal air exhaust pipeline, and the abnormal air exhaust pipeline is provided with a DVN iodine filter and a DVN iodine exhaust fan;
the air supply pipeline is connected with an air supply isolation air door of the EBA system, and when the air supply isolation air door is opened, air flow flows into the EBA system from the air supply pipeline through the air supply isolation air door;
the exhaust pipeline is connected with an exhaust isolation air door of the EBA system, and when the exhaust isolation air door is opened, airflow flows out of the EBA system from the exhaust isolation air door through the exhaust pipeline.
Optionally, the first specified duration comprises 25 seconds.
Specific limitations on the nuclear power plant containment ventilation control system can be found in the above limitations on the nuclear power plant containment ventilation control method, and are not described in detail here.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
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