阅读说明：本技术 核电机组热停工况下单区域丧失后的状态恢复方法及系统 (State recovery method and system after single area loss under thermal shutdown condition of nuclear power unit ) 是由 李永进 陈信仁 史长青 尹亚华 宋玉亮 赵东阳 刘洋 刘东亮 张旭峰 于 2018-01-12 设计创作，主要内容包括：本发明公开了一种核电机组热停工况下单区域丧失后的状态恢复方法,包括：在热停工况下,对丧失区域中的工艺设备进行断电隔离；对所述丧失区域的数字化控制系统DCS进行隔离；利用相邻区域的不间断电源对所述丧失区域的DCS供电,并恢复所述丧失区域的DCS；对所述丧失区域中的所述工艺设备上电,将核电机组恢复至热停工况下的正常在线状态。本发明还公开了一种核电机组热停工况下单区域丧失后的状态恢复系统。本发明能够在热停工况下直接恢复丧失区域而不对其他区域的正常运行造成影响,有效节约大量时间和资源。(The invention discloses a state recovery method after a single region is lost under a thermal shutdown condition of a nuclear power unit, which comprises the following steps: under thermal shutdown conditions, power-off isolation of process equipment in the lost zone is performed; isolating the digital control system DCS of the lost area; supplying power to the DCS of the lost area by using an uninterrupted power supply of an adjacent area, and recovering the DCS of the lost area; and powering on the process equipment in the loss area, and restoring the nuclear power unit to a normal online state under a thermal shutdown condition. The invention also discloses a state recovery system after the single region is lost under the thermal shutdown condition of the nuclear power unit. The method can directly recover the lost area under the thermal shutdown condition without influencing the normal operation of other areas, thereby effectively saving a large amount of time and resources.)

1. A state recovery method after single area loss under the thermal shutdown condition of a nuclear power unit is characterized by comprising the following steps:

under thermal shutdown conditions, power-off isolation of process equipment in the lost zone is performed;

Isolating the digital control system DCS of the lost area;

supplying power to the DCS of the lost area by using an uninterrupted power supply of an adjacent area, and recovering the DCS of the lost area;

And recovering the power supply of the process equipment in the loss area, and recovering the nuclear power unit to a normal online state under a thermal shutdown condition.

2. The method for recovering the state of the single zone lost under the thermal shutdown condition of the nuclear power generating unit as claimed in claim 1, wherein the step of performing power-off isolation on the process equipment in the lost zone specifically comprises the steps of:

And acquiring the process equipment and the isolation mode which need to be completely isolated in the loss area by combining an electrical load list, an electrical system single line diagram and the online state of the process system so as to perform power-off isolation on the process equipment.

3. The method of claim 2, wherein said process equipment includes main water supply line size isolation valves, main pump gland seals injection, pressurizer safety valves, chemical and volumetric control system RCV charge and discharge function related valves, safety injection system RIS injection pumps and valves associated with said lost zone, facility cooling water system RRI and service water system SEC of interest.

4. the method for recovering the state of the single zone lost under the thermal shutdown condition of the nuclear power generating unit according to claim 1, wherein the step of isolating the digital control system DCS of the lost zone specifically comprises the steps of:

forcibly isolating potentially affected interaction signals during DCS recovery for the lost area;

Isolating the communication network between the DCS in the lost area and the DCS in other areas.

5. The method for recovering the state of the single zone after the single zone is lost in the thermal shutdown condition of the nuclear power generating unit according to claim 4, wherein the step of forcibly isolating the potentially affected interaction signals during the DCS recovery of the lost zone specifically includes:

Combining a DCS network signal interaction list and a hard-wired interaction list of a nuclear power generating unit, and acquiring process system functions which may have signal jump and state inversion during DCS recovery of the lost area based on a nuclear power generating unit state and a system design manual under a thermal shutdown condition;

And executing the forced isolation of corresponding interactive signals in other areas according to the acquired functions of the process system.

6. The method of claim 5, wherein the potentially affected interaction signals include steam generator level control signals, reactor loop temperature control signals, reactor loop pressure and level control signals, safety system action signals, unit cold sources, and cold chain related impact signals.

7. The method for recovering the state of a single zone lost under the thermal shutdown condition of a nuclear power generating unit as recited in claim 5, further comprising:

And for the process system function which cannot carry out signal forced isolation, making an operator auxiliary intervention preventive measure during DCS recovery so that an operator can intervene in the state of the nuclear power generating unit during DCS recovery.

8. The method for recovering the state of the single zone lost under the thermal shutdown condition of the nuclear power generating unit according to claim 4, wherein the recovering of the DCS of the lost zone specifically comprises:

Restoring the communication between the DCS in the lost area and the DCS in other areas;

after the state of the machine set is stable, the forced isolation of the potential affected interaction signals is cancelled.

9. the method for recovering the state of the single zone lost under the thermal shutdown condition of the nuclear power generating unit according to claim 8, wherein the recovering of the communication between the DCS in the lost zone and DCS in other zones specifically comprises:

Restoring a PIPS cabinet of a protective instrument pretreatment system, a preferred drive control system PACS cabinet, a controller in a KCO cabinet of a nuclear island DCS control system, a card in the KCO cabinet and an isolation cabinet in sequence;

And accessing the DCS network of the lost area, and recovering the communication between the DCS of the lost area and the DCS of other areas.

10. A state recovery system after loss of a single zone in a thermal shutdown condition of a nuclear power generating unit, which can apply the state recovery method after loss of a single zone in a thermal shutdown condition of a nuclear power generating unit according to any one of claims 1 to 9, the system comprising:

The power-off isolation module is connected with the process equipment in the loss area and is used for carrying out power-off isolation on the process equipment in the loss area under the thermal shutdown condition;

the DCS isolation module is connected with the DCS of the lost area and used for isolating the digital control system DCS of the lost area;

The DCS recovery module is connected with the DCS of the lost area and used for supplying power to the DCS of the lost area by using an uninterrupted power supply of an adjacent area and recovering the DCS of the lost area; and the number of the first and second groups,

and the recovery module is connected with the process equipment in the loss area and used for recovering the power supply of the process equipment in the loss area and recovering the nuclear power unit to a normal online state under a thermal shutdown condition.

Technical Field

the invention relates to the technical field of nuclear power stations, in particular to a method and a system for recovering a state of a nuclear power unit after a single area is lost under a thermal shutdown condition.

background

The pressurized water reactor nuclear power station mainly comprises a pressurized water reactor, a primary loop (reactor loop) system, a secondary loop (steam turbine loop) system and the like. Nuclear fission occurs within a reactor core consisting of nuclear fuel within a pressure vessel. The pressurized water reactor takes low-enriched uranium as fuel and light water as coolant and moderator. The heat released by nuclear fission is carried out of the reactor by high pressure water flowing through a primary system within the reactor and transferred to the secondary water in a boiler generator. The steam generated after the water is heated pushes the steam turbine, and the steam turbine drives the generator to generate electricity.

In order to meet the requirement of redundancy control and increase the safety of the nuclear power unit, the pressurized water reactor nuclear power station is provided with four subareas, an electrical system and a process system of the pressurized water reactor nuclear power station distribute equipment and control signals in the four subareas according to functions, and the four subareas maintain the safe operation of the nuclear power unit together. A large amount of signal interaction and equipment interlocking control exist among the four partitions. The safe operation of the nuclear power unit is maintained by designing the four subareas together, and when one subarea is lost (the whole area is power-off, equipment in the area is stopped, a control signal in the area cannot be sent to the other three subareas, and the whole area becomes a black box), the pressurized water reactor nuclear power unit can maintain the unit in a hot stop state by the other three subareas.

when a single-region loss working condition occurs in a thermal shutdown condition of a nuclear power unit, if a certain prevention and control measure is not taken to directly recover the loss region of power transmission to an electrical panel under the thermal shutdown condition, the nuclear power unit cannot be stabilized under the thermal shutdown condition, and equipment maloperation of the other three regions is caused, for example, the temperature of a loop of a nuclear island cannot be controlled due to the error tripping of a main pump of an RCP (reactor coolant system), and abnormal phenomena such as the pressure of the loop cannot be controlled due to the following leakage isolation are caused. Therefore, in the prior art, the unit is generally withdrawn to a cold shutdown state for fault clearing, after the fault clearing, equipment in a single area is gradually electrified and recovered, and then the unit state is promoted to a hot shutdown working condition. However, since the thermal shutdown condition is followed by the cold shutdown condition and the state is then raised to the hot shutdown condition, a lot of time and resources are consumed, and meanwhile, due to the limitation of the design life of a primary circuit pressure vessel, the unit cannot bear too many state changes from the cold shutdown to the hot shutdown.

disclosure of Invention

the invention provides a method and a system for recovering the state of a single area lost under the thermal shutdown condition of a nuclear power unit, aiming at the problems in the prior art, and the method and the system can directly recover the lost area under the thermal shutdown condition without influencing the normal operation of other areas, thereby effectively saving a large amount of time and resources.

the technical scheme provided by the invention for the technical problem is as follows:

On one hand, the invention provides a state recovery method after a single area is lost under a thermal shutdown condition of a nuclear power unit, which comprises the following steps:

under thermal shutdown conditions, power-off isolation of process equipment in the lost zone is performed;

Isolating the digital control system DCS of the lost area;

Supplying power to the DCS of the lost area by using an uninterrupted power supply of an adjacent area, and recovering the DCS of the lost area;

and recovering the power supply of the process equipment in the loss area, and recovering the nuclear power unit to a normal online state under a thermal shutdown condition.

Further, the power-off isolation of the process equipment in the loss area specifically includes:

And acquiring the process equipment and the isolation mode which need to be completely isolated in the loss area by combining an electrical load list, an electrical system single line diagram and the online state of the process system so as to perform power-off isolation on the process equipment.

Further, the process equipment comprises a main water supply pipeline size isolation valve, main pump shaft seal injection, a pressure stabilizer safety valve, valves related to charging and discharging functions of a chemical and volume control system RCV, safety injection system RIS injection pumps and valves related to the lost area, equipment cooling water system RRI and an important service water system SEC.

further, the isolating the digital control system DCS of the lost area specifically includes:

Forcibly isolating potentially affected interaction signals during DCS recovery for the lost area;

isolating the communication network between the DCS in the lost area and the DCS in other areas.

further, the forcibly isolating the potentially affected interaction signals during the DCS recovery period of the lost area specifically includes:

Combining a DCS network signal interaction list and a hard-wired interaction list of a nuclear power generating unit, and acquiring process system functions which may have signal jump and state inversion during DCS recovery of the lost area based on a nuclear power generating unit state and a system design manual under a thermal shutdown condition;

And executing the forced isolation of corresponding interactive signals in other areas according to the acquired functions of the process system.

Further, the potentially affected interaction signals include steam generator water level control signals, reactor loop temperature control signals, reactor loop pressure and water level control signals, safety system action signals, unit cold sources, and cold chain related effect signals.

further, the recovery method further comprises:

And for the process system function which cannot carry out signal forced isolation, making an operator auxiliary intervention preventive measure during DCS recovery so that an operator can intervene in the state of the nuclear power generating unit during DCS recovery.

further, the recovering the DCS of the lost area specifically includes:

Restoring the communication between the DCS in the lost area and the DCS in other areas;

after the state of the machine set is stable, the forced isolation of the potential affected interaction signals is cancelled.

further, the recovering the communication between the DCS in the lost area and the DCS in the other areas specifically includes:

Restoring a PIPS cabinet of a protective instrument pretreatment system, a preferred drive control system PACS cabinet, a controller in a KCO cabinet of a nuclear island DCS control system, a card in the KCO cabinet and an isolation cabinet in sequence;

And accessing the DCS network of the lost area, and recovering the communication between the DCS of the lost area and the DCS of other areas.

in another aspect, the present invention provides a system for applying the method for recovering a state after a single area is lost under a thermal shutdown condition of a nuclear power plant, where the system includes:

the power-off isolation module is used for performing power-off isolation on the process equipment in the loss area under the thermal shutdown condition;

the DCS isolation module is used for isolating the digital control system DCS in the lost area;

the DCS recovery module is used for supplying power to the DCS in the lost area by utilizing an uninterrupted power supply of an adjacent area and recovering the DCS in the lost area; and the number of the first and second groups,

and the recovery module is used for recovering the power supply of the process equipment in the loss area and recovering the nuclear power unit to a normal online state under a thermal shutdown condition.

the technical scheme provided by the embodiment of the invention has the following beneficial effects:

after a single area is completely lost under the thermal shutdown condition, firstly, the process equipment in the lost area is powered off and isolated, then, the DCS in the lost area is isolated, then, the process equipment in the lost area is powered on, and the nuclear power unit is recovered to be in a normal online state under the thermal shutdown condition, so that the lost area is directly recovered under the thermal shutdown condition without influencing the normal operation of other areas, and in the recovery process, the nuclear power unit can be stabilized under the thermal shutdown condition and does not need to be removed to be in a cold shutdown condition after the thermal shutdown condition, and a large amount of time and resources are effectively saved.

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 description of the embodiments will be briefly introduced 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 creative efforts.

Fig. 1 is a schematic flow chart of a state recovery method after a single zone is lost under a thermal shutdown condition of a nuclear power generating unit according to an embodiment of the present invention;

FIG. 2 is a general architecture diagram of a nuclear power generating unit according to a first embodiment of the present invention;

Fig. 3 is an overall architecture diagram of a nuclear power generating unit DCS system according to a first embodiment of the present invention;

Fig. 4 is a schematic specific flowchart of a state recovery method after a single zone is lost under a thermal shutdown condition of a nuclear power plant according to an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a state recovery system after a single zone is lost under a thermal shutdown condition of a nuclear power generating unit according to a second embodiment of the present invention.

Detailed Description

in order to solve the technical problems that a large amount of time and resources are consumed for recovering a lost area in the prior art, the invention aims to provide a method for recovering a state of a single area lost under a thermal shutdown condition of a nuclear power unit, which has the core idea that: after a single area is completely lost under the thermal shutdown condition, firstly, the process equipment in the lost area is powered off and isolated, then the DCS of the lost area is isolated, then the DCS is recovered, the process equipment in the lost area is powered on, and the nuclear power unit is recovered to be in a normal online state under the thermal shutdown condition, so that the lost area is directly recovered under the thermal shutdown condition, the normal operation of other areas is not affected, and a large amount of time and resources are effectively saved.

in order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.