CN103400612A - Early warning method and system for unidentifiable leakage of nuclear power stations - Google Patents
Early warning method and system for unidentifiable leakage of nuclear power stations Download PDFInfo
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- 239000007788 liquid Substances 0.000 claims abstract description 207
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- 230000002209 hydrophobic effect Effects 0.000 claims description 32
- 238000009530 blood pressure measurement Methods 0.000 claims description 6
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- 238000012544 monitoring process Methods 0.000 description 12
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- 238000011156 evaluation Methods 0.000 description 1
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- 238000012986 modification Methods 0.000 description 1
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- 239000003758 nuclear fuel Substances 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
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Abstract
The invention discloses an early warning method for unidentifiable leakage of nuclear power stations, which comprises the following steps that: a distributed control system (DCS) receives liquid level change information sent by a continuous liquid level measuring meter; the DCS determines the leakage rate of the unidentifiable leakage according to the liquid level change information; the DCS judges whether the leakage rate exceeds a preset early warning value; if a judge result shows that the leakage rate exceeds the preset early warning value, early warning information is sent to a main control system. Through sending the liquid level change information to a DCS through a continuous liquid level measuring meter, whether the rate exceeds a preset early warning value is judged according to the liquid level change information by the DCS, and if the judge result shows that the leakage rate exceeds the preset early warning value, the early warning information is sent to the main control system, A situation that when the unidentifiable leakage occurs during the running of the nuclear power station, the early warning information can be sent timely is realized. In addition, the invention also discloses an early warning system for the unidentifiable leakage of the nuclear power stations.
Description
Technical Field
The invention belongs to the field of nuclear power station monitoring, and particularly relates to an early warning method and system for unidentifiable leakage of a nuclear power station.
Background
The nuclear power plant generates electricity by means of fission energy released by fission of radioactive substances. The nuclear fuel continuously generates chain fission reaction in the reactor pressure vessel, and a large amount of heat energy is released. The released heat energy is carried to the steam generator by the coolant circulating in the primary loop, so that the circulating water in the secondary loop is vaporized, and the steam turbine is driven to do work. When the nuclear power plant normally operates, the primary circuit coolant is usually in a high-temperature and high-pressure state, and once leakage occurs at a primary circuit pressure boundary, a large amount of vaporization and leakage of the coolant can be caused. The Leakage of the nuclear power plant mainly comprises identifiable Leakage (Identified Leakage) and unidentifiable Leakage (Unidentified Leakage). Wherein, the identifiable leakage is classified into two types, one type is leakage which can be collected and guided into a pit, a collection tank or a collection system, such as seal leakage of a pump or packing leakage of a valve; another type is leakage into the containment atmosphere from a known source that does not affect the operation of the unidentifiable leak monitoring system. While an unidentifiable leak refers to all leaks except the identifiable leak until the source of the unidentifiable leak is determined, such as a Reactor Coolant Pressure Boundary (RCPB) leak.
Monitoring for unidentifiable leaks has been a difficult problem in the field of nuclear power. At present, the monitoring method about unidentifiable leakage mainly adopts a float type measuring and monitoring method, namely a float type flowmeter is used for measuring the liquid level of a drainage pit. When the float is lifted by a force greater than the weight of the float immersed in fluid, the float rises and the area of the annular gap increases, the flow rate of the fluid at the annular gap drops immediately, the differential pressure between the upper end and the lower end of the float decreases, and the lifting force acting on the float decreases accordingly until the lifting force is equal to the weight of the float immersed in fluid, and the float is stabilized at a certain height. The float position is the corresponding liquid level. Under the stable working condition, the liquid level of the drainage pit can be directly read according to the position of the floater. The liquid level of the drainage pit can be roughly measured by the float-type flowmeter, the method is simple, the cost is low, but the leakage rate of unidentifiable leakage cannot be accurately measured, and early warning cannot be carried out according to the leakage condition of unidentifiable leakage; meanwhile, the design of the float-type flowmeter is simple, so that the requirements of shock resistance and the like cannot be met.
Disclosure of Invention
The invention aims to: the method and the device can realize the early warning of the unidentifiable leakage in the operation process of the nuclear power station by judging whether the leakage rate exceeds the preset early warning value or not and sending early warning information to a main control system when the leakage rate exceeds the preset early warning value.
In order to achieve the above object, the present invention provides an early warning method for unidentifiable leakage of a nuclear power station, which comprises:
a digital instrument control system DCS receives liquid level change information sent by a continuous measurement liquid level meter;
the DCS determines the leakage rate of unidentifiable leakage according to the liquid level change information;
the DCS judges whether the leakage rate exceeds a preset early warning value or not;
and if the leakage rate is judged to exceed a preset early warning value, sending early warning information to a main control system.
As an improvement of the warning method for unidentifiable leakage of the nuclear power station, the method further comprises the following steps:
and the main control system determines the leakage source of the unidentifiable leakage according to the early warning information.
As an improvement of the early warning method for unidentifiable leakage of the nuclear power station, before the digital control system receives liquid level change information sent by the continuous measurement liquid level meter, the method further comprises the following steps:
the continuous measurement liquid level meter measures the liquid level change condition of the drain pit during normal operation of the nuclear power station and the liquid level change condition of the drain pit during unidentifiable leakage.
As an improvement of the warning method for unidentifiable leakage of the nuclear power station, the method further comprises the following steps:
and the continuous measurement liquid level meter determines the drain pit liquid level change rate and the drain pit liquid level change rate when the nuclear power station normally operates and the unrecognizable leakage occurs according to the drain pit liquid level change condition and the unrecognizable leakage occurring liquid level change condition during normal operation.
As an improvement of the warning method for unidentifiable leakage of the nuclear power station, the method further comprises the following steps:
a pump is arranged in the drainage pit, and the continuous measurement liquid level meter determines whether to start the pump for draining water according to the liquid level change condition of the drainage pit during normal operation and/or the liquid level change condition of the drainage pit during unidentifiable leakage; or,
and the continuous measurement liquid level meter determines whether to stop the pump to drain water according to the drain pit liquid level change condition during normal operation and/or the drain pit liquid level change condition during unidentifiable leakage.
As an improvement of the warning method for unidentifiable leakage of the nuclear power station, the method further comprises the following steps:
the continuous measurement liquid level meter adopts a differential pressure measurement mode for measurement.
As an improvement of the early warning method for unidentifiable leakage of the nuclear power station, the DCS determines the leakage rate of unidentifiable leakage according to the liquid level change information, and includes:
and the DCS determines the leakage rate of the unidentifiable leakage by combining the sectional area of the hydrophobic pit according to the liquid level change rate of the hydrophobic pit during normal operation and the liquid level change rate of the hydrophobic pit when the unidentifiable leakage occurs.
As an improvement of the warning method for unidentifiable leakage of the nuclear power station, the method further comprises the following steps:
and setting the early warning value to be 1GPM, and if the leakage rate is judged to exceed 1GPM, sending early warning information to the main control system.
In order to achieve the above object, the present invention further provides an early warning system for unrecognizable leakage of a nuclear power plant, including:
the continuous measurement liquid level meter is used for sending drain pit liquid level change information;
a digital instrument control system DCS used for receiving liquid level change information sent by the continuous measurement liquid level meter and determining the leakage rate of unidentifiable leakage according to the liquid level change information; and judging whether the leakage rate exceeds a preset early warning value, and if so, sending early warning information to a main control system.
As an improvement of the early warning system for unidentifiable leakage of the nuclear power plant, the system further comprises:
and the main control system is used for determining the leakage source of the unidentifiable leakage according to the early warning information.
As an improvement of the warning system for unidentifiable leakage of the nuclear power plant, the continuous measuring liquid level meter is further configured to: and measuring the liquid level change condition of the drain pit when the nuclear power station normally operates and the liquid level change condition of the drain pit when unidentifiable leakage occurs.
As an improvement of the warning system for unidentifiable leakage of the nuclear power plant, the continuous measuring liquid level meter is further configured to: and determining the drain pit liquid level change rate and the drain pit liquid level change rate when the nuclear power station normally operates and the unrecognizable leakage occurs according to the drain pit liquid level change condition and the unrecognizable leakage occurrence drain pit liquid level change condition during normal operation.
As an improvement of the early warning system for unidentifiable leakage of the nuclear power plant, the system further comprises: the draining pump is used for draining the water in the draining pit;
the continuous measurement liquid level meter is also used for determining whether to start a pump for draining water according to the drainage pit liquid level change condition during normal operation and/or the drainage pit liquid level change condition during unidentifiable leakage; or,
and the continuous measurement liquid level meter is also used for determining whether to stop the pump drainage according to the drainage pit liquid level change condition during normal operation and/or the drainage pit liquid level change condition during unidentifiable leakage.
As an improvement of the early warning system for the unidentifiable leakage of the nuclear power station, the continuous measurement liquid level meter adopts a differential pressure measurement mode for measurement.
As an improvement of the early warning system for the unidentifiable leakage of the nuclear power station, the DCS determines the leakage rate of the unidentifiable leakage by combining the sectional area of the hydrophobic pit according to the liquid level change rate of the hydrophobic pit during normal operation and the liquid level change rate of the hydrophobic pit when the unidentifiable leakage occurs.
As an improvement of the early warning system for unidentifiable leakage of the nuclear power plant, the system further comprises:
and setting the early warning value to be 1GPM, and if the leakage rate is judged to exceed 1GPM, sending early warning information to the main control system.
Compared with the prior art, the early warning method and the early warning system based on the unidentifiable leakage of the nuclear power station have the following beneficial technical effects: the continuous measurement liquid level meter sends liquid level change information to the DCS, the DCS judges whether the leakage rate exceeds a preset early warning value according to the liquid level change information, and sends early warning information to the main control system when judging that the leakage rate exceeds the preset early warning value. The early warning information is timely sent when the unidentifiable leakage occurs in the operation of the nuclear power station; meanwhile, as the anti-seismic 1-class component is selected by the continuous measurement liquid level meter, the requirement of Safe Shutdown Earthquake (SSE) is met, and a good technical effect is achieved.
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The method and system for warning unidentifiable leakage of a nuclear power plant according to the present invention will be described in detail with reference to the accompanying drawings and specific embodiments, wherein:
fig. 1 provides a flowchart of an embodiment of a warning method for unidentifiable leakage of a nuclear power plant according to the present invention.
Fig. 2 provides a flow chart of yet another embodiment of the warning method for unidentifiable leakage of the nuclear power plant.
Fig. 3 provides a flow chart of yet another embodiment of the warning method for unidentifiable leakage of the nuclear power plant.
FIG. 4 provides a schematic diagram of one embodiment of a nuclear power plant unidentifiable leak early warning system of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantageous technical effects of the present invention clearer, the present invention is described in further detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
China is facing a rapid development situation in nuclear power, and AP1000 and CPR1000 units are two main technical schemes adopted by the recent construction of nuclear power plants in China. The method is used for evaluating the result of unidentifiable leakage under the condition of a design benchmark accident, is one of important contents of evaluation and safety analysis of the environmental influence of the nuclear power plant, monitoring unidentifiable leakage of a primary circuit of the pressurized water reactor nuclear power plant, and monitoring the leakage by adopting a method for measuring the liquid level of a hydrophobic pit of a reactor factory building. The principle is as follows: when an unrecognizable leak in the primary circuit occurs, the primary coolant will enter the containment vessel in two forms, one in a gaseous form (vaporized to steam and eventually condensed to water) and the other in a liquid form (by gravity to a sump). The gaseous steam is finally condensed under the cooling effect of the ventilation system and is collected to a drainage pit of a reactor factory building through a condensed water coil of the ventilation system; liquid water passes through a floor drain arranged in the workshop and is finally collected into the same drainage pit.
Referring to fig. 1, fig. 1 provides an early warning method for unidentifiable leakage of a nuclear power plant, which specifically includes:
Before a Digital Control System (DCS) receives liquid level change information sent by a continuous measurement liquid level meter in step 101, the continuous measurement liquid level meter measures the liquid level change condition of a drain pit when a nuclear power station normally operates and the liquid level change condition of the drain pit when unidentifiable leakage occurs. And the continuous measurement liquid level meter determines the drain pit liquid level change rate and the drain pit liquid level change rate when the nuclear power station normally operates and the unrecognizable leakage occurs according to the drain pit liquid level change condition and the unrecognizable leakage occurrence drain pit liquid level change condition during normal operation.
Specifically, the water source of the hydrophobic pit mainly comes from 3 aspects, including: running overflow water, draining floor drain and ventilating system condensed water. The drainage pit is provided with a pump and a liquid level meter, and the liquid level meter can comprise a continuous measurement liquid level meter with a continuous measurement function and a liquid level switch.
During the normal operation of the nuclear power station, the water source of the drainage pit only has operation overflow water, and the amount of the operation overflow water is usually constant or approximately constant according to the operation experience. When the liquid level of the drainage pit exceeds a high liquid level set value H1, starting a pump, and discharging redundant water to other process systems, usually a waste liquid treatment system; when the level of the sump is below the low level setpoint L1, the pump will be stopped. Within this time period t1, the change in liquid level Δ L1= H1-L1. The slope k1=Δl1/t1 of the pit liquid level change curve, i.e., the pit liquid level change rate in normal operation.
When unrecognizable leakage occurs, as the condensed water of the ventilation system and the drain water enter the drain pit, the liquid level of the drain pit changes faster, and in the time period t2, the slope of the change curve of the liquid level of the drain pit is k2= [ Delta ] L2/t2, and [ Delta ] k = k1-k2, namely the change rate of the liquid level of the drain pit when unrecognizable leakage occurs.
Optionally, a pump is arranged in the drainage pit, and the continuous measurement liquid level meter determines whether to start pump drainage according to the drainage pit liquid level change condition during normal operation and/or the drainage pit liquid level change condition during unidentifiable leakage. For example, if k1 is found to be significantly different from k2, the pump may be activated to drain and the level switch may be opened.
Or, the continuous measurement liquid level meter determines whether to stop the pump drainage according to the drainage pit liquid level change condition in normal operation and/or the drainage pit liquid level change condition in the case of unidentifiable leakage. For example, if k1 is found to be not much different from k2, the pump may be stopped from draining and the level switch may be turned off.
And 103, determining the leakage rate of unidentifiable leakage by the DCS according to the liquid level change information.
And the DCS determines the leakage rate of the unidentifiable leakage by combining the sectional area of the hydrophobic pit according to the liquid level change rate of the hydrophobic pit during normal operation and the liquid level change rate of the hydrophobic pit when the unidentifiable leakage occurs. Leak rate = (k2-k1) xS, where S hydrophobic pit cross-sectional area.
And 105, judging whether the leakage rate exceeds a preset early warning value by the DCS.
Optionally, the warning value is set to 1 Gallon Per Minute (GPM).
And step 107, if the leakage rate is judged to exceed the preset early warning value, sending early warning information to the main control system.
And if the leakage rate is judged to be greater than the early warning value 1GPM, sending early warning information to the main control system.
Optionally, the main control system determines that the leakage source of the leakage cannot be identified according to the early warning information.
Further, the continuous measurement liquid level meter adopts a differential pressure measurement mode for measurement. Specifically, by means of a differential pressure measurement mode, the high-pressure side is the bottom pressure of the hydrophobic pit, the low-pressure side is the atmospheric pressure, the differential pressure is Δ P, and then the liquid level is Δ P/(ρ xg), wherein ρ is the density of water, and g is the gravity acceleration.
Furthermore, the continuous measurement liquid level meter should be selected to meet the requirement that the measurement time of the instrument control system is less than 1 hour. The change of the drainage pit liquid level which can be accurately identified by the liquid level meter is as follows: ax HxS, in units of l; if the unidentifiable leak of 1GPM all enters the hydrophobic pit, the response time is: (AxHxS)/3.8 in min. When (AxHxS)/3.8 is less than 60min, the instrument system is considered to meet the requirement of RG1.45 on response time; when (AxHxS)/3.8 is greater than 60min, the instrument system is deemed to not meet the RG1.45 requirements for response time. Wherein A is the precision of the continuous measurement liquid level meter, H is the full range of the continuous measurement liquid level meter, and S is the sectional area of the hydrophobic pit.
Because the time for transmitting the instrument signal and processing DCS is extremely short, the instrument signal is ignored.
In the embodiment of the invention, the continuous measurement liquid level meter sends liquid level change information to the DCS, the DCS judges whether the leakage rate exceeds a preset early warning value according to the liquid level change information, and sends early warning information to the main control system when judging that the leakage rate exceeds the preset early warning value, so that the early warning information can be sent in time when unidentifiable leakage occurs in the operation of a nuclear power station; meanwhile, as the continuous measurement liquid level meter selects anti-seismic 1 type components, the requirements of safe shutdown and earthquake SSE are met, and a good technical effect is obtained.
Referring to fig. 2 in combination, fig. 2 is a schematic diagram of an embodiment of a warning method for unidentifiable leakage of a nuclear power plant, and in particular, a monitoring principle of a liquid level of a hydrophobic pit. As mentioned previously, the source of water for the hydrophobic pits comes primarily from 3 areas, including: running overflow water, draining floor drain and ventilating system condensed water. The hydrophobic pit is provided with 2 pumps and a liquid level meter, and the liquid level meter can comprise a continuous measurement liquid level meter with a continuous measurement function and a liquid level switch.
During the normal operation of the nuclear power station, the water source of the drainage pit only has operation overflow water, and the amount of the operation overflow water is usually constant or approximately constant according to the operation experience. When the liquid level of the drainage pit exceeds a high liquid level set value H1, starting a pump 01, and discharging redundant water to other process systems, usually a waste liquid treatment system; when the level of the sump is below the low level setpoint L1, the pump will be stopped 01. Within this time period t1, the change in liquid level Δ L1= H1-L1. The slope k1=Δl1/t1 of the pit liquid level change curve, i.e., the pit liquid level change rate in normal operation.
When unidentifiable leakage occurs and is small, as the condensed water of the ventilation system and the drain water also enter the drain pit, the liquid level of the drain pit changes rapidly, and in the time period t2, the slope of the change curve of the liquid level of the drain pit is k2= [ Delta ] L2/t2, namely the change rate of the liquid level of the drain pit when unidentifiable leakage occurs.
When unrecognizable leakage is large, when the liquid level of the drainage pit exceeds a high liquid level set value H1, after the 01 pump is started, the liquid level continuously rises to exceed a set high secondary liquid adding level H2, the 02 pump is started, and when the liquid level is reduced to L1, the 01 pump and the 02 pump are simultaneously closed.
Referring to fig. 3 in combination, fig. 3 is a schematic diagram of an embodiment of a warning method for unidentifiable leakage of a nuclear power plant. In particular, a leakage rate calculation principle is provided. During the normal operation of the nuclear power station, the water source of the drainage pit only has operation overflow water, and the amount of the operation overflow water is usually constant or approximately constant according to the operation experience. When the liquid level of the drainage pit exceeds a high liquid level set value H1, starting a pump 01, and discharging redundant water to other process systems, usually a waste liquid treatment system; when the level of the sump is below the low level setpoint L1, the pump will be stopped 01. Within this time period t1, the change in liquid level Δ L1= H1-L1. The slope k1=Δl1/t1 of the pit liquid level change curve, i.e., the pit liquid level change rate in normal operation.
When unidentifiable leakage occurs and is small, as the condensed water of the ventilation system and the drain water also enter the drain pit, the liquid level of the drain pit changes rapidly, and in the time period t2, the slope of the change curve of the liquid level of the drain pit is k2= [ Delta ] L2/t2, namely the change rate of the liquid level of the drain pit when unidentifiable leakage occurs. Wherein the leak rate for the time period is: (k2-k1) x S, wherein S is a cross-sectional area of the hydrophobic pit.
When unrecognizable leakage is large, when the liquid level of the drainage pit exceeds a high liquid level set value H1, after the 01 pump is started, the liquid level continuously rises to exceed a set high secondary liquid adding level H2, the 02 pump is started, and when the liquid level is reduced to L1, the 01 pump and the 02 pump are simultaneously closed. According to the principle, the slopes of the ascending sections of the liquid level of the drainage pit are respectively k3 and k4 obtained by continuously measuring the liquid level meter. Wherein the leakage rate for this period is (k3-k1) x S, where S is the cross-sectional area of the hydrophobic pit.
Referring to fig. 4 in combination, fig. 4 is a schematic diagram of an embodiment of a warning system for unidentifiable leakage of a nuclear power plant, which includes: a continuous measurement liquid level meter 401 and a digital control system DCS 403. Wherein,
a continuous measurement level gauge 401 for sending pit level variation information.
A digital instrument control system DCS403 for receiving the liquid level change information sent by the continuous measurement liquid level meter 401 and determining the leakage rate of unidentifiable leakage according to the liquid level change information; and judging whether the leakage rate exceeds a preset early warning value, and if so, sending early warning information to the main control system.
Specifically, the water source of the hydrophobic pit mainly comes from 3 aspects, including: running overflow water, draining floor drain and condensing water in a ventilation system. The hydrophobic sump is provided with a pump and a level gauge which may comprise a continuous measuring level gauge 401 and a level switch with continuous measuring function.
During the normal operation of the nuclear power station, the water source of the drainage pit only has operation overflow water, and the amount of the operation overflow water is usually constant or approximately constant according to the operation experience. When the liquid level of the drainage pit exceeds a high liquid level set value H1, starting a pump, and discharging redundant water to other process systems, usually a waste liquid treatment system; when the level of the sump is below the low level setpoint L1, the pump will be stopped. During this period t1, the continuous measuring level gauge 401 measures a change Δ L1= H1-L1 in the liquid level. The slope k1=Δl1/t1 of the pit liquid level change curve, i.e., the pit liquid level change rate in normal operation.
When unrecognizable leakage occurs, as the condensed water of the ventilation system and the drain floor drain also enter the drain pit, the liquid level of the drain pit changes faster, and in the time period t2, the slope of the change curve of the liquid level of the drain pit measured by the continuous measuring liquid level meter 401 is k2= [ delta ] L2/t2, and [ delta ] k = k1-k2, namely the change rate of the liquid level of the drain pit when unrecognizable leakage occurs.
Optionally, a pump is disposed in the drain pit, and the continuous measurement level gauge 401 determines whether to start pumping according to a drain pit liquid level change situation during normal operation and/or a drain pit liquid level change situation when an unrecognizable leak occurs. For example, if k1 is found to be significantly different from k2, pump discharge may be initiated and the level switch may be instructed to open.
Alternatively, the continuous measurement level gauge 401 determines whether to stop pump drainage based on the change in sump level during normal operation and/or the change in sump level when an unrecognizable leak occurs. For example, if k1 is found to be not much different from k2, the pump may be stopped from draining and the level switch may be commanded off.
And the DCS403 determines the leakage rate of the unidentifiable leakage by combining the sectional area of the hydrophobic pit according to the liquid level change rate of the hydrophobic pit during normal operation and the liquid level change rate of the hydrophobic pit when the unidentifiable leakage occurs. Leak rate = (k2-k1) x S, where S hydrophobic pit cross-sectional area.
And (4) optional. And setting an early warning value to be 1 Gallon Per Minute (GPM) in the DCS403, and if the leakage rate is judged to be greater than the early warning value 1GPM, sending early warning information to the main control system.
Optionally, the early warning system based on the unidentifiable leakage of the nuclear power plant further includes a main control system, which is configured to determine the leakage source of the unidentifiable leakage according to the early warning information.
Optionally, the principle of the scheme and the system can also be applied to an activity concentration monitoring and early warning scheme of the containment atmosphere F-18 aerosol, a monitoring and early warning scheme of the activity concentration of the containment atmosphere inert gas, a monitoring and early warning scheme of extraction and analysis of steam leaked from the main pipeline and a humidity monitoring and early warning scheme of the main pipeline.
For the implementation method and the process of the system, reference may be made to the method embodiments described in the foregoing embodiments, and details are not described here.
In combination with the above detailed description of the present invention, it can be seen that the present invention has at least the following advantageous technical effects over the prior art: the continuous measurement liquid level meter sends liquid level change information to the DCS, the DCS judges whether the leakage rate exceeds a preset early warning value according to the liquid level change information, and sends early warning information to the main control system when judging that the early warning value exceeds the preset early warning value. The early warning information is timely sent when the unidentifiable leakage occurs in the operation of the nuclear power station; meanwhile, as the anti-seismic 1-class component is selected by the continuous measurement liquid level meter, the requirement of Safe Shutdown Earthquake (SSE) is met, and a good technical effect is achieved.
The present invention can be modified and adapted appropriately from the above-described embodiments, according to the principles described above. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (16)
1. An early warning method for unidentifiable leakage of a nuclear power station is characterized by comprising the following steps:
a digital instrument control system DCS receives liquid level change information sent by a continuous measurement liquid level meter;
the DCS determines the leakage rate of unidentifiable leakage according to the liquid level change information;
the DCS judges whether the leakage rate exceeds a preset early warning value or not;
and if the leakage rate is judged to exceed a preset early warning value, sending early warning information to a main control system.
2. The method of claim 1, further comprising:
and the main control system determines the leakage source of the unidentifiable leakage according to the early warning information.
3. The method of claim 2, wherein before the digital control system receives the liquid level change information sent by the continuous measurement liquid level meter, the method further comprises:
the continuous measurement liquid level meter measures the liquid level change condition of the drain pit during normal operation of the nuclear power station and the liquid level change condition of the drain pit during unidentifiable leakage.
4. The method of claim 3, further comprising:
and the continuous measurement liquid level meter determines the drain pit liquid level change rate and the drain pit liquid level change rate when the nuclear power station normally operates and the unrecognizable leakage occurs according to the drain pit liquid level change condition and the unrecognizable leakage occurring liquid level change condition during normal operation.
5. The method of claim 4, further comprising:
a pump is arranged in the drainage pit, and the continuous measurement liquid level meter determines whether to start the pump for draining water according to the liquid level change condition of the drainage pit during normal operation and/or the liquid level change condition of the drainage pit during unidentifiable leakage; or,
and the continuous measurement liquid level meter determines whether to stop the pump to drain water according to the drain pit liquid level change condition during normal operation and/or the drain pit liquid level change condition during unidentifiable leakage.
6. The method according to any one of claims 1 to 5, further comprising:
the continuous measurement liquid level meter adopts a differential pressure measurement mode for measurement.
7. The method of claim 4, wherein the DCS determines a leak rate of an unidentifiable leak from the liquid level variation information, comprising:
and the DCS determines the leakage rate of the unidentifiable leakage by combining the sectional area of the hydrophobic pit according to the liquid level change rate of the hydrophobic pit during normal operation and the liquid level change rate of the hydrophobic pit when the unidentifiable leakage occurs.
8. The method according to claim 6 or 7, characterized in that the method further comprises:
and setting the early warning value to be 1GPM, and if the leakage rate is judged to exceed 1GPM, sending early warning information to the main control system.
9. An early warning system for unidentifiable leakage of a nuclear power plant, the system comprising:
the continuous measurement liquid level meter is used for sending drain pit liquid level change information;
a digital instrument control system DCS used for receiving liquid level change information sent by the continuous measurement liquid level meter and determining the leakage rate of unidentifiable leakage according to the liquid level change information; and judging whether the leakage rate exceeds a preset early warning value, and if so, sending early warning information to a main control system.
10. The warning system for unidentifiable leaks in nuclear power plants as set forth in claim 9, further comprising:
and the main control system is used for determining the leakage source of the unidentifiable leakage according to the early warning information.
11. The nuclear power plant unidentifiable leak early warning system as recited in claim 10, wherein the continuous measurement level gauge is further configured to: and measuring the liquid level change condition of the drain pit when the nuclear power station normally operates and the liquid level change condition of the drain pit when unidentifiable leakage occurs.
12. The warning system for unidentifiable leakage of nuclear power plant as set forth in claim 11,
the continuous measurement level gauge is further configured to: and determining the drain pit liquid level change rate and the drain pit liquid level change rate when the nuclear power station normally operates and the unrecognizable leakage occurs according to the drain pit liquid level change condition and the unrecognizable leakage occurrence drain pit liquid level change condition during normal operation.
13. The warning system for unidentifiable leaks in nuclear power plants as claimed in claim 12, further comprising: the draining pump is used for draining the water in the draining pit;
the continuous measurement liquid level meter is also used for determining whether to start a pump for draining water according to the drainage pit liquid level change condition during normal operation and/or the drainage pit liquid level change condition during unidentifiable leakage; or,
and the continuous measurement liquid level meter is also used for determining whether to stop the pump drainage according to the drainage pit liquid level change condition during normal operation and/or the drainage pit liquid level change condition during unidentifiable leakage.
14. The warning system for unidentifiable leakage of nuclear power plant as claimed in any one of claims 9 to 13, wherein said continuous measuring level meter measures by differential pressure measurement.
15. The warning system for unidentifiable leakage of nuclear power plant as set forth in claim 12,
the DCS determines the leakage rate of unidentifiable leakage according to the liquid level change information, and comprises the following steps:
and the DCS determines the leakage rate of the unidentifiable leakage by combining the sectional area of the hydrophobic pit according to the liquid level change rate of the hydrophobic pit during normal operation and the liquid level change rate of the hydrophobic pit when the unidentifiable leakage occurs.
16. The warning system for unidentifiable leaks in nuclear power plants as claimed in claim 14 or 15, further comprising:
and setting the early warning value to be 1GPM, and if the leakage rate is judged to exceed 1GPM, sending early warning information to the main control system.
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| CN110243428A (en) * | 2019-04-29 | 2019-09-17 | 苏州热工研究院有限公司 | Liquid level shakes dynamic height assessment system and its working method under nuclear power station liquid reserve tank earthquake |
| CN114038592A (en) * | 2021-10-12 | 2022-02-11 | 中广核陆丰核电有限公司 | Nuclear power plant primary circuit leakage rate monitoring method and device |
| CN114038592B (en) * | 2021-10-12 | 2024-03-15 | 中广核陆丰核电有限公司 | Nuclear power plant primary loop leakage rate monitoring method and device |
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