A kind of nuclear power unit control rod avoids engineered safeguards features from acting method and system when falling extremely
阅读说明：本技术 一种核电机组控制棒异常掉落时避免专设安全设施动作的方法及系统 (A kind of nuclear power unit control rod avoids engineered safeguards features from acting method and system when falling extremely ) 是由 柳文斌 易绍峰 黄佳 陈辉 张明华 孔俊 于 2019-08-26 设计创作，主要内容包括：本发明公开了一种核电机组控制棒异常掉落时避免专设安全设施动作的方法。所述方法包括如下步骤：所述棒位探测器将探测到的控制棒棒位信号传输至所述数据采集柜；所述数据采集柜将接收到的所述控制棒棒位信号进行转码处理；所述棒位逻辑柜接收并根据经过转码处理的所述控制棒棒位信号分析落入堆芯的控制棒数量,并在分析结果为2s内有6束以上控制棒落入堆芯时发出反应堆停堆信号。从而,所述棒位逻辑柜在控制棒落入堆芯后可及时触发停堆信号,以保证反应堆实际停堆后,及时触发汽机跳机,从而避免安全注入系统因主蒸汽管线压力低而触发。(The invention discloses a kind of methods for avoiding engineered safeguards features to act when nuclear power unit control rod is fallen extremely.Described method includes following steps: the control stick position signal detected is transmitted to the data and acquires cabinet by the stick location probe；The control stick position signal received is carried out transcoding processing by the data acquisition cabinet；Stick position logic cabinet receives and falls into according to the control stick position signal analysis by transcoding processing the control rod quantity of reactor core, and issues reactor shutdown signal when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s.To which stick position logic cabinet can trigger shutdown signal after control rod falls into reactor core in time, after guaranteeing the practical shutdown of reactor, steam turbine chaser be triggered in time, so that safety injection system be avoided to trigger because main steam pipe line pressure is low.)
1. a kind of nuclear power unit control rod avoids engineered safeguards features from acting method when falling extremely, the nuclear power unit include Rod position indicating systems are digitized, the digitlization rod position indicating systems include stick location probe, data acquisition cabinet and stick position logic Cabinet, which is characterized in that described method includes following steps:
The control stick position signal detected is transmitted to the data and acquires cabinet by the stick location probe；
The control stick position signal received is carried out transcoding processing by the data acquisition cabinet；
Stick position logic cabinet receives and falls into the control of reactor core according to the control stick position signal analysis by transcoding processing Stick quantity processed, and reactor shutdown signal is issued when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s.
2. nuclear power unit control rod according to claim 1 avoids engineered safeguards features from acting method when falling extremely, It is characterized in that, the nuclear power unit further includes protection and the safety monitoring system for generating shutdown signal, the stick position is patrolled It collects cabinet to connect with the protection and safety monitoring system signal, stick position logic cabinet is to have 6 beams or more in 2s in analysis result Control rod falls into reactor core and issues reactor shutdown when not receiving from the shutdown signal of the protection and safety monitoring system Signal.
3. nuclear power unit control rod according to claim 1 avoids engineered safeguards features from acting method when falling extremely, It is characterized in that, the digitlization rod position indicating systems further include the electricity for connecting the stick location probe and data acquisition cabinet The control stick position signal detected is transmitted to the data by the cable and acquires cabinet by cable, the stick location probe.
4. nuclear power unit control rod according to claim 1 avoids engineered safeguards features from acting method when falling extremely, It is characterized in that, the method also includes following steps:
Logic delay 3s when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s in the stick position triggers steam turbine trip letter Number.
5. a kind of nuclear power unit control rod avoids engineered safeguards features from acting system when falling extremely, the nuclear power unit include Rod position indicating systems are digitized, the digitlization rod position indicating systems include stick location probe, data acquisition cabinet and stick position logic Cabinet, which is characterized in that
The stick location probe, which is used to for the control stick position signal detected to be transmitted to the data, acquires cabinet；
The data acquisition cabinet is used to the control stick position signal received carrying out transcoding processing；
Stick position logic cabinet is used to receive and falls into reactor core according to the control stick position signal analysis by transcoding processing Control rod quantity, and analyze result be 2s in there is the above control rod of 6 beams to fall into reactor core when issue reactor shutdown signal.
6. nuclear power unit control rod according to claim 5 avoids engineered safeguards features from acting system when falling extremely, It is characterized in that, the nuclear power unit further includes protection and the safety monitoring system for generating shutdown signal, the stick position is patrolled It collects cabinet to connect with the protection and safety monitoring system signal, stick position logic cabinet is used in analysis result be to have 6 beams in 2s The above control rod falls into reactor core and issues reactor when not receiving from the shutdown signal of the protection and safety monitoring system Shutdown signal.
7. nuclear power unit control rod according to claim 5 avoids engineered safeguards features from acting system when falling extremely, It is characterized in that, the digitlization rod position indicating systems further include the electricity for connecting the stick location probe and data acquisition cabinet Cable, the stick location probe are used to that the control stick position signal detected to be transmitted to the data by the cable and acquire Cabinet.
8. nuclear power unit control rod according to claim 5 avoids engineered safeguards features from acting system when falling extremely, It is characterized in that, stick position logic is used for the delay 3s touching when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s Send out steam turbine trip signal.
Technical field
The present invention relates to nuclear safety technical fields, and in particular to the security technology area of the nuclear power unit of such as AP1000, More particularly to a kind of nuclear power unit control rod avoids engineered safeguards features from acting method and system when falling extremely.
Background technique
AP1000 unit need to consider the machinery or hydraulic characteristic(s) of such as equipment when determining npp safety range of operation The requirement etc. of limitation or reactor core heat transfer.In operational envelope, allow that power plant is adjusted to respond normal power generation and want It asks.The design of power plant provides enough safety allowances, so that power plant operates normally the transient state that variation introduces and will not cause uneasiness Full power plant's operating condition.Control system of power plant makes reactor operation within safety limit, and keeps certain allowance.Control Serious transient state caused by the control command and failure or generation II class or Group III event of system exception can all make power plant's operating condition Develop to the direction close to safety limit.Influence of the hypothetical event (I class event) to power plant safety limit value is analyzed in design, only Shutdown is just triggered close to safety limit, security system.Reactor emergency shut-down is that protection and safety monitoring system are being expected certain A kind of defencive function executed when one Protection parameters are close to its safety limit.The process for realizing reactor shutdown is drive response Heap shutdown breaker opens the coil losing electricity for making control rod drive mechanism, and control rod falls into reactor core by gravity.
AP1000 unit starts reactor shutdown function: source range (SR) high neutron fluence rate in situations；It is intermediate Range (IR) high neutron fluence rate；Power range (PR) high neutron fluence rate (low setting valve)；Power range PR high neutron fluence Rate (high setting valve)；The high positive change rate of power range PR neutron fluence rate；Overtemperature △ T (OTDT)；Overpower △ T (OPDT)；Surely Low 2 pressure of depressor；Low 2 flow of reactor coolant；Low 2 revolving speed of reactor coolant pump (RCP)；High 2 temperature of RCP bearing water； High 2 pressure of voltage-stablizer；High 3 liquid level of voltage-stablizer；Low 2 liquid level of steam generator (SG)；3 liquid level of SG high；Automatically unloading system (ADS) Driving；Core makeup tank (CMT) injection；The driving of S signal；Manual reactor shutdown；Passive residual heat removal (PRHR) driving.
In order to better illustrate, AP1000 unit presently, there are defect, it is necessary to AP1000 control rod form and control Rod drive mechanism processed does a simple illustration.
Totally 69 groups of AP1000 C&P systems, be divided into two classes by the material of absorber in cluster: one kind is known as black matrix control Stick (RCCA), it is another kind of to be known as grey body control rod (GRCA).AP1000 control rod is using 53 groups of RCCA and 16 group of GRCA (referring to figure 1).RCCA is divided into three classes: temperature control rod, axial power distributed controll stick and shut-down rod, and RCCA is mainly compensatory reactionBu Changfanying heap fortune Caused changes of reactivity when row, that is, the variation of power and temperature.RCCA is by one group of independent neutron absorbing bar and to consolidate The connection handle for determining stick top is constituted, and absorbent material is silver-indium-cadmium alloy, it has very strong absorbability simultaneously to thermal neutron And there is resonance absorption cross section other enough, considerably increase its value.GRCA is operated for Steam Generator in Load Follow, provides mechanical benefit (MSHIM) is repaid to reduce even substitution and use the chemical shimming for changing boron concentration.Machine Design, CRDM and and the fuel of GRCA The interface of component and guide pipe is all identical as RCCA.GRCA is made of 24 sticks, and top is fixedly connected with starframe, in addition to GRCA The intensity of absorbent material decreases compared to RCCA, GRCA and RCCA outer dimension having the same.
AP1000 C&P systems are divided into control rod group (37 groups) and shut-down rod group (32 groups) in function.Control rod group includes M stick group and AO stick group, M stick group refer to coolant temperature control rod group, for the control of coolant average temperature, including MA, MB, MC, MD, M1, M2 stick group, wherein MA, MB, MC and MD are made of GRCA, and M1, M2 are made of RCCA；AO stick group refers to axial dipole field Control rod group, for controlling axial power distribution.Shut-down rod group includes SD1, SD2, SD3 and SD4.Control rod group and shut-down rod group Each stick group at least there are four control rod, control rod group can be controlled manually or automatically in the axial position of reactor core.Reactor After shutdown signal triggering, all C&P systems are inserted into reactor core.
The major function of control rod drive mechanism (being referred to as CRDM below) is with pre-set velocity promotion or underthrust 53 Some designated groups in RCCA and 16 GRCA control mean temperature (Tavg)-- heap for flowing through Core cooling agent with this Core power control key parameter, while maintaining reactor core that there is acceptable Neutron flux distribution.During starting with shutdown, control The insertion and proposition of component control reactor core changes of reactivity together with reactor coolant boron concentration.
In order to make all control rod groups cooperate together, the CRDM in every group of RCCA or GRCA can when acting Holding acts in agreement, and CRDM must be uniformly controlled.Each CRDM is under the jurisdiction of a specific control rod group, utilizes these controls Stick group processed carries out reactive control, axial power distributed controll, or realizes reactor shutdown.CRDM and C&P systems are set Meter allows to carry out Steam Generator in Load Follow to uncomfortable boron in the most of the time of core life.Power plant during normal operation, CRDM's Design allows RCCA and GRCA to be in any position in stick stroke.Control rod promotion rely on be electromagnetic force, and underthrust according to What is leaned on is gravity.The stick position of control rod by 48 discrete coils in the position instruction device assembly that is mounted on outside rod travel housing come It measures.When the ferromagnet on control rod drive rod top partially passes through coil centerline, each magnetic coil can be sensed The movement and presence of stick can both measure control stick position.
The power supply of control rod drive mechanism is illustrated below, control rod drive mechanism is normally by different lines After pressing bus to drive motor generator power generation, Jing Lianglie shutdown switch is powered, when normal operation, if among the above any One parameter is more than shutdown limit value, i.e. triggering reactor shutdown signal (P4), while triggering shutdown switch and disconnecting, subsequent control rod Driving mechanism power loss, control rod fall under gravity into reactor core, reactor shutdown.Delay 5s triggers vapour after the triggering of P4 signal The tripping of turbine generator group, maintains a secondary circuit nuclear heat power-balance, and unit safety is maintained to stablize.
In addition it is negative to be also provided with neutron flux other than the Reactor trip similar with AP1000 is arranged by traditional CPR1000 Change rate height (- 5Pn/2s) Reactor trip.The purpose of negative rate of neutron high Reactor trip be prevent reactor capability run single beam (or Person part) control rod surprisingly falls into reactor core, and it causes (non-scram region) local power peak factor high, burns fuel can.And with Traditional CPR1000 presurized water reactor is compared, and AP1000 unit is current and the high (- 5%Pn/2s) shutdown of the negative change rate of not set neutron flux Signal is protected, tracing it to its cause has following two reason:
1) AP1000 unit is provided with the real-time core power monitoring of design offer in linear heat generation rate distribution monitoring system: scram When accident, caused by neutron flux distortion in heap, requirements is saved by Technical specification 3.2.5 at this time, by linear heat generation rate distribution prison Examining system (OPDMS) is to peak value linear power density, DNBR, FNAnd SDM is monitored, once operator will be required beyond limitation Restore in 1 hour (if do not restored, then by power to 25%Pn) in 4 hours；
2) fast prompt drop power (RPRS) system is arranged in AP1000, and in high power (being greater than 70%Pn), load wink range of decrease degree is super When crossing 40%Pn, such as steam turbine gets rid of unloaded load, gets rid of station service, and RPRS puts into operation, and triggers four groups of selected control rods and falls into heap bottom, Quickly secondary circuit load is without shutdown for tracking (balance or partial equilibrium), if the negative change rate height of setting -5%Pn/2s neutron stops Heap signal, will lead to when quickly starting power system and triggers shutdown.
This just brings following consequence, when control rod drive mechanism power loss (such as: Ningde Thermal Power Plant N-LOER-3-20150004: On June 24th, 2015, No. 3 power of the assembling unit operations of Ningde nuclear power carry out control rod drive mechanism electricity for cooperation electrical repair personnel No. 2 motor-generator sets in source are inspected periodically, No. 2 motor-generator sets of the operations staff in stoppage in transit control rod drive mechanism power supply Afterwards, due to accidentally closing No. 2 generator outlet breakers, 2 generator overcurrent protections of control rod drive mechanism power supply is caused to act Tripping, control rod drive mechanism electrical source of power power loss lead to Dropping of control rod, and triggering RPN power range neutron flux change rate is high Protection act causes No. 3 unit reactors to stop automatically), control rod falls into reactor core (about 2s), traditional CPR1000 because of self gravity Because being provided with high (- 5Pn/2s) Reactor trip signal of the negative change rate of neutron flux, shutdown signal, Jin Erfa can be issued The signal of Turbo-generator Set tripping out.And AP1000 unit, since the negative change rate of not set neutron flux high (- 5Pn/2s) stops Heap protects signal, thus works as control rod drive mechanism power loss, and control rod still can fall under gravity into reactor core (about 2s), but It is that since shutdown limit value is not up to thus shutdown signal can not be triggered (the low 13.479Mpa of primary Ioops pressure jumps heap signal in core function Rate is down to P10 or less and is blocked automatically, therefore control rod falls into reactor core and will not jump heap because pressure is low), therefore steam turbine can not be triggered Chaser, reactor will persistently be subcooled at this time, and peace group's injected system is finally triggered due to main steam pipe line pressure low (3.86Mpa) Movement then triggers P4 signal again, could trigger steam turbine after the 5s that is delayed and take off mouth.I.e. AP1000 unit will be because of control rod driving machine Structure power loss and directly trigger safety injection system movement (engineered safeguard system).According to " Guangdong Lufeng nuclear power first stage of the project The 3rd chapter of preliminary safety analysis report " in require, the safety injection system action frequency upper limit is 20 in the AP1000 power plant entire phase in longevity It is secondary, if primary simple shutdown event directly triggers safety injection system starting, unit safety stable operation will be brought not Sharp consequence, and following serious consequence will be brought:
1. reactor i.e. practical shutdown after control rod falls into reactor core, but shutdown signal can not be issued, lead to not send out Steam turbine trip signal out, steam turbine steam inlet condition deteriorate, and steam turbine exhaust stage blade humidity increases, and steam turbine damage risk increases, and steam turbine makes It is reduced with the service life；
2. finally triggering safety injection system movement after control rod drive mechanism power loss, it is unfavorable for unit allocation, increases machine The risk of group control period, and increase the time that unit restores again, influence nuclear power unit nuclear safety and economy；
In summary, the Reactor trip design of AP1000 unit can not guarantee unit safety well at present.
Summary of the invention
The technical problem to be solved by the present invention is to for above-mentioned problem in the prior art, in order to cope with such as Safety injection system is directly triggered after the control rod drive mechanism power loss of the nuclear power unit of AP1000 and starts this event, provides one The method and system that kind nuclear power unit control rod avoids engineered safeguards features from acting when falling extremely are this serious to avoid generating Consequence.
The technical solution adopted by the present invention to solve the technical problems is: providing a kind of nuclear power unit control rod and falls extremely When avoid engineered safeguards features act method, the nuclear power unit include digitlization rod position indicating systems, the digital rod Position instruction system includes stick location probe, data acquisition cabinet and stick position logic cabinet, and described method includes following steps:
The control stick position signal detected is transmitted to the data and acquires cabinet by the stick location probe；
The control stick position signal received is carried out transcoding processing by the data acquisition cabinet；
Stick position logic cabinet receives and falls into reactor core according to the control stick position signal analysis by transcoding processing Control rod quantity, and analyze result be 2s in there is the above control rod of 6 beams to fall into reactor core when issue reactor shutdown signal.
By using the method in above-mentioned technical proposal, stick position logic cabinet can and trigger after control rod falls into reactor core Shutdown signal triggers steam turbine chaser, to avoid safety injection system because of main steam after guaranteeing the practical shutdown of reactor in time Line pressure is low and triggers.
The optimization for the method for avoiding engineered safeguards features to act when falling extremely as nuclear power unit control rod of the invention Scheme, the nuclear power unit further include the protection and safety monitoring system for generating shutdown signal, stick position logic cabinet with The protection is connected with safety monitoring system signal, and stick position logic cabinet is to have the above control rod of 6 beams in 2s in analysis result It falls into reactor core and issues reactor shutdown signal when not receiving from the shutdown signal of the protection and safety monitoring system.
The optimization for the method for avoiding engineered safeguards features to act when falling extremely as nuclear power unit control rod of the invention Scheme, the digitlization rod position indicating systems further include the cable for connecting the stick location probe and data acquisition cabinet, institute It states stick location probe and the control stick position signal detected is transmitted to by the data acquisition cabinet by the cable.
The optimization for the method for avoiding engineered safeguards features to act when falling extremely as nuclear power unit control rod of the invention Scheme, the method also includes following steps:
Logic delay 3s when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s in the stick position triggers steam turbine and jumps Lock signal.
Correspondingly, the present invention also provides avoid engineered safeguards features from acting when a kind of nuclear power unit control rod is fallen extremely System, the nuclear power unit include digitlization rod position indicating systems, the digitlization rod position indicating systems include stick position detect Device, data acquisition cabinet and stick position logic cabinet；
The stick location probe, which is used to for the control stick position signal detected to be transmitted to the data, acquires cabinet；
The data acquisition cabinet is used to the control stick position signal received carrying out transcoding processing；
Stick position logic cabinet is used to receive and be fallen into according to the control stick position signal analysis by transcoding processing The control rod quantity of reactor core, and reactor shutdown letter is issued when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s Number.
The improvement for the system for avoiding engineered safeguards features to act when falling extremely as nuclear power unit control rod of the invention, The nuclear power unit further includes the protection and safety monitoring system for generating shutdown signal, stick position logic cabinet and the guarantor Shield is connected with safety monitoring system signal, and stick position logic cabinet is used in analysis result be to have the above control rod of 6 beams to fall in 2s Enter reactor core and issues reactor shutdown signal when not receiving from the shutdown signal of the protection and safety monitoring system.
The improvement for the system for avoiding engineered safeguards features to act when falling extremely as nuclear power unit control rod of the invention, The digitlization rod position indicating systems further include the cable for connecting the stick location probe and data acquisition cabinet, the stick position Detector, which is used to that the control stick position signal detected to be transmitted to the data by the cable, acquires cabinet.
The improvement for the system for avoiding engineered safeguards features to act when falling extremely as nuclear power unit control rod of the invention, Stick position logic is used for the delay 3s when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s and triggers steam turbine trip letter Number.
The method for implementing that engineered safeguards features is avoided to act when nuclear power unit control rod provided by the invention is fallen extremely, can To reach following the utility model has the advantages that described method includes following steps: the stick location probe believes the control stick position detected Number it is transmitted to the data acquisition cabinet；The data acquisition cabinet carries out the control stick position signal received at transcoding Reason；Stick position logic cabinet receives and falls into the control of reactor core according to the control stick position signal analysis by transcoding processing Stick quantity, and reactor shutdown signal is issued when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s.To institute It states stick position logic cabinet and can and trigger shutdown signal after control rod falls into reactor core, after guaranteeing the practical shutdown of reactor, touch in time Steam turbine chaser is sent out, so that safety injection system be avoided to trigger because main steam pipe line pressure is low.
Detailed description of the invention
Fig. 1 is AP1000 control rod composition schematic diagram in the present invention；
Fig. 2 is the method for avoiding engineered safeguards features from acting when nuclear power unit control rod provided by the invention is fallen extremely Flow chart；
Fig. 3 is that the signal for avoiding engineered safeguards features from acting when nuclear power unit control rod provided by the invention is fallen extremely is patrolled Collect figure；
Fig. 4 is the system for avoiding engineered safeguards features from acting when nuclear power unit control rod provided by the invention is fallen extremely Block diagram.
Specific embodiment
For a clearer understanding of the technical characteristics, objects and effects of the present invention, now control attached drawing is described in detail A specific embodiment of the invention.Obviously, described embodiments are only a part of the embodiments of the present invention, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are obtained without creative efforts The every other embodiment obtained, shall fall within the protection scope of the present invention.
The present invention provides a kind of methods for avoiding engineered safeguards features to act when nuclear power unit control rod is fallen extremely.Institute It states in nuclear power unit of the method mainly for solving such as AP1000 and directly triggers Safety Injection after control rod drive mechanism power loss The problem of system starts.
Firstly the need of explanation, AP1000 unit itself includes digitlization rod position indicating systems, the digital rod position Instruction system includes stick location probe, cable, data acquisition cabinet, stick position logic cabinet and Rod drop test subsystem.Each stick Location probe includes 48 coils, and 48 coils are divided into two coil groups, i.e. A coil group and B coil group, each coil Group includes 24 coils, is alternately distributed, and control rod is detected with these coils the location of in reactor core.Every beam control rod is equal A stick location probe is configured to detect the position of the corresponding control rod.The cable is used for the stick location probe Signal connection between the data acquisition cabinet, each stick location probe are separately connected two cables, A coil group The cable is respectively connect with B coil group.Data acquisition cabinet is located in containment building, and critical function is continuous monitoring institute There are the stick position of control rod, including two cabinets of A, B, each cabinet receives the line of the corresponding group of each stick location probe respectively Ring signal is simultaneously handled, i.e., A cabinet connects the cable that one end is connect with A coil group, and B cabinet connects one end and B coil group connects The cable connect, data acquire cabinet by the coil signal received be converted to Gray code (the common Reliability codes of binary code, Also known as Gray code).Stick position logic cabinet receives the stick position Gray code and related data of the data acquisition cabinet in containment, And corresponding logical process is carried out, the stick position data of two coil groups are integrated to the stick position for analyzing full precision, are also provided Various information is finally sent to power plant's real- time data network by the logical process of all kinds of alarms.The Rod drop test subsystem is carrying out The rod drop time of control rod is measured when Rod drop test, the Rod drop test subsystem includes being located inside data acquisition cabinet Data acquisition equipment and a Rod drop test cabinet being located at outside containment.
Referring to fig. 2, the side for avoiding engineered safeguards features to act when nuclear power unit control rod provided by the invention is fallen extremely Method includes the following steps:
The control stick position signal detected is transmitted to the data and acquires cabinet by the stick location probe；
The control stick position signal received is carried out transcoding processing by the data acquisition cabinet；
Stick position logic cabinet receives and falls into reactor core according to the control stick position signal analysis by transcoding processing Control rod quantity, and analyze result be 2s in there is the above control rod of 6 beams to fall into reactor core when issue reactor shutdown signal.
By using the method in above-mentioned technical proposal, stick position logic cabinet can and trigger after control rod falls into reactor core Shutdown signal triggers steam turbine chaser, to avoid safety injection system because of main steam after guaranteeing the practical shutdown of reactor in time Line pressure is low and triggers.
Further, the AP1000 unit further includes protection and the safety monitoring system for generating shutdown signal, institute It states stick position logic cabinet to connect with the protection and safety monitoring system signal, stick position logic cabinet is to have in 2s in analysis result The above control rod of 6 beams falls into reactor core and issues reaction when not receiving from the shutdown signal of the protection and safety monitoring system Heap shutdown signal (referring to Fig. 3).In this way, shutdown signal is avoided to be repeated triggering.Shutdown letter can be issued as early as possible in this way Number, and then issue Turbo-generator Set and take off message number, a possibility that safety injection system acts is effectively prevented, unit is protected Safety, and protect the safety of Turbo-generator Set.
Further, the digitlization rod position indicating systems further include connecting the stick location probe and data acquisition The control stick position signal detected is transmitted to the data by the cable and acquired by the cable of cabinet, the stick location probe Cabinet.In this way, the original equipment of AP1000 unit is made full use of, without the digital rod position to the AP1000 unit itself Instruction system makees the improvement in terms of hardware device, and the method provided by the invention can be realized, be easy to implement.
Optionally, avoided when the nuclear power unit control rod is fallen extremely engineered safeguards features act method further include Following steps: logic delay 3s when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s in the stick position triggers steam turbine Trip signal.The reason of being designed in this way is, it is contemplated that the 5s triggering that is delayed when normal shutdown on the AP1000 unit design stops Machine, stick position logic delay 3s when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s trigger steam turbine trip letter Number, it can be to avoid (i.e. the practical shutdown of reactor but do not issue shutdown signal) after control rod drive mechanism power loss, Wu Fafa Shutdown signal out, steam turbine can not take off mouth, eventually lead to because main steam pipe line pressure is low trigger peace infuse this event generation.
The present invention also provides the systems for avoiding engineered safeguards features to act when a kind of nuclear power unit control rod is fallen extremely (referring to fig. 4).The system by AP1000 unit digitlization rod position indicating systems in stick location probe, data acquisition cabinet and Stick position logic cabinet is constituted.Wherein, the stick location probe is used to the control stick position signal detected being transmitted to the data Acquire cabinet；The data acquisition cabinet is used to the control stick position signal received carrying out transcoding processing；The stick position is patrolled The control rod quantity that cabinet is used to receive and falls into reactor core according to the control stick position signal analysis by transcoding processing is collected, and Reactor shutdown signal is issued when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s.In this way, the system can be Control rod can and trigger shutdown signal after falling into reactor core, after guaranteeing the practical shutdown of reactor, trigger steam turbine chaser in time, thus Safety injection system is avoided to trigger because main steam pipe line pressure is low.
Preferably, the system also includes the AP1000 units for generating the protection and safety monitoring of shutdown signal System, stick position logic cabinet are connect with the protection and safety monitoring system signal, and stick position logic cabinet is for analyzing As a result believe to there is the above control rod of 6 beams to fall into reactor core in 2s and not receiving from the protection and the shutdown of safety monitoring system Number when issue reactor shutdown signal.In this way, shutdown signal is avoided to be repeated triggering.
Preferably, the digitlization rod position indicating systems further include connecting the stick location probe and data acquisition cabinet Cable, the stick location probe adopts for the control stick position signal detected to be transmitted to the data by the cable Collect cabinet.In this way, the original equipment of AP1000 unit is made full use of, without the digital rod to the AP1000 unit itself Position instruction system make hardware device in terms of improvement, the system provided by the invention can be realized, be easy to implement.
Preferably, stick position logic can also be used in when analyzing result is to have the above control rod of 6 beams to fall into reactor core in 2s The 3s that is delayed triggers steam turbine trip signal.Stick position logic is when analyzing result is to have the above control rod of 6 beams to fall into reactor core in 2s The 3s that is delayed triggers steam turbine trip signal.The reason of being designed in this way is, it is contemplated that unit is normal on the AP1000 unit design The 5s triggering that is delayed when shutdown is shut down, and stick position logic is to have the above control rod of 6 beams to fall into reactor core time delay in 2s in analysis result When 3s trigger steam turbine trip signal, (the practical shutdown of reactor but can not be sent out to avoid after control rod drive mechanism power loss Shutdown signal out), shutdown signal can not be issued, steam turbine can not thread off, and eventually lead to and trigger peace because main steam pipe line pressure is low Infuse the generation of this event.
The method for implementing that engineered safeguards features is avoided to act when nuclear power unit control rod provided by the invention is fallen extremely, can To reach following the utility model has the advantages that described method includes following steps: the stick location probe believes the control stick position detected Number it is transmitted to the data acquisition cabinet；The data acquisition cabinet carries out the control stick position signal received at transcoding Reason；Stick position logic cabinet receives and falls into the control of reactor core according to the control stick position signal analysis by transcoding processing Stick quantity, and reactor shutdown signal is issued when analyzing result and being to have the above control rod of 6 beams to fall into reactor core in 2s.To institute It states stick position logic cabinet and can and trigger shutdown signal after control rod falls into reactor core, after guaranteeing the practical shutdown of reactor, touch in time Steam turbine chaser is sent out, so that safety injection system be avoided to trigger because main steam pipe line pressure is low.
The embodiment of the present invention is described with above attached drawing, but the invention is not limited to above-mentioned specific Embodiment, the above mentioned embodiment is only schematical, rather than restrictive, those skilled in the art Under the inspiration of the present invention, without breaking away from the scope protected by the purposes and claims of the present invention, it can also make very much Form, all of these belong to the protection of the present invention.