Backup protection constant value deviation checking method for intermediate range of nuclear instrumentation system

Abstract

The invention relates to the technical field of system maintenance, in particular to a backup protection constant value deviation checking method for an intermediate range of a nuclear instrumentation system. The invention discloses a backup protection constant value deviation checking method for an intermediate range of a nuclear instrumentation system. The method comprises the following steps: acquiring a real-time current mean value of an intermediate range channel according to an acquisition instruction; obtaining a linear relation between the real-time reactor core thermal power and the real-time current mean value of the intermediate range channel according to the linear instruction; according to the linear relation and the real-time current mean value, real-time reactor core thermal power is calculated; obtaining a power mean value of thermal power of the reactor of the kernel instrumentation system in a preset time period; judging whether a power deviation value between the power mean value and the real-time reactor core thermal power meets a preset condition or not; if the preset condition is met, modifying the protection setting value; and if not, protecting the constant value to maintain the current situation. Therefore, the risk caused by data switching is avoided, the reliability of data is effectively improved, and the reliability of a reactor protection function and the safety of a nuclear power unit are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of system maintenance, and in particular to a method for calibrating a backup protection fixed value deviation of an intermediate range of a nuclear instrument system. Background Art

[0002] The PN system is a critical safety system in pressurized water reactor (PWR) nuclear power plants. It continuously measures and monitors the reactor's nuclear power, power distribution, and power variations, while also providing certain control and protection functions. Its most important protection function is providing an emergency shutdown signal to the reactor protection system when the reactor's nuclear power, or its variation, exceeds a set value. To achieve these monitoring, control, and protection functions, the nuclear instrumentation system measures the reactor neutron flux using a series of measurement channels distributed outside the reactor. These channels include three types: source range channels, intermediate range channels, and power range channels.

[0003] The power range of the nuclear instrument system is equipped with a high neutron flux rate shutdown protection signal. When the nuclear power value indicated by the power range of the nuclear instrument system reaches the high neutron flux rate shutdown protection set value of 109% FP, the shutdown protection signal will be triggered and the control rod group will fall into the core by gravity, thereby shutting down the reactor. This is one of the most important protection signals set during normal power operation of the unit to deal with abnormal increases in nuclear power.

[0004] Practice has proved that in the pressurized water reactor nuclear power units that have been mature for many years (such as CPR1000), the power range signal indication of the nuclear instrument system is stable and reliable, and the power range neutron injection rate high shutdown protection signal can provide effective protection for the reactor and effectively improve the safety of the nuclear power unit.

[0005] However, during the power operation phase, the overall core neutron flux level and power distribution continuously change, and the nuclear instrumentation system's intermediate-range detection instruments also experience drift. These factors, compounded by each other, can easily cause a significant deviation between the actual set intermediate-range protection settings of the nuclear instruments and the current value corresponding to 118% reactor power (FP). This makes it difficult to effectively achieve backup protection, affecting its reliability in ensuring reactor safety. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for calibrating the backup protection fixed value deviation of the intermediate range of a nuclear instrument system.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for calibrating the backup protection fixed value deviation of the intermediate range of a nuclear instrument system, comprising the following steps:

[0008] Obtain the real-time current average value of the intermediate range channel according to the acquisition instruction;

[0009] Acquire a linear relationship between the real-time core thermal power of the intermediate range channel and the real-time current mean value according to a linear instruction;

[0010] Calculating the real-time core thermal power according to the linear relationship and the real-time current mean;

[0011] Obtaining a power average value of the reactor thermal power of the nuclear instrument system within a preset time period;

[0012] Determine whether the power deviation value between the power mean and the real-time core thermal power meets a preset condition; if the preset condition is met, modify the protection setting; if not, maintain the status quo of the protection setting.

[0013] Preferably, acquiring the real-time current mean value of the intermediate range channel according to the acquisition instruction includes:

[0014] Obtaining a preset interval duration from the acquisition instruction;

[0015] Acquire the real-time current average value according to the preset interval duration;

[0016] The real-time current mean value is averaged according to the number of the intermediate range channels to obtain the real-time current mean value.

[0017] Preferably, the preset interval is less than or equal to twenty minutes.

[0018] Preferably, the obtaining of the average power value of the reactor thermal power of the nuclear instrument system within a preset time period includes:

[0019] Obtain the power mean value that is consistent with the preset interval duration.

[0020] Preferably, the step of obtaining the average power value of the reactor thermal power of the nuclear instrument system within a preset time period further includes:

[0021] The power mean is obtained by averaging the total power of the mid-range channels according to the number of the mid-range channels.

[0022] Preferably, obtaining the linear relationship between the real-time core thermal power of the intermediate range channel and the real-time current mean value according to the linear instruction includes:

[0023] According to the data interval requirement in the linear instruction, a historical current average value and a historical core thermal power are obtained;

[0024] The linear relationship among the historical current average, the historical core thermal power, the real-time current average and the real-time core thermal power is established based on the power formula principle.

[0025] Preferably, the linear relationship is as follows:

[0026] The real-time core thermal power is the historical core thermal power multiplied by the ratio between the historical current average and the real-time current average.

[0027] Preferably, the data interval requirement includes the historical current average value and the historical core thermal power collected last time.

[0028] Preferably, the preset condition includes: the power deviation value is greater than 1.5% of the full power.

[0029] Preferably, the modifying of the protection constant includes calculating an adjustment constant according to the power deviation value, and updating the backup protection constant to the adjustment constant.

[0030] The implementation of the present invention has the following beneficial effects:

[0031] The present invention obtains the real-time current mean of the intermediate-range channel according to an acquisition instruction and the linear relationship between the real-time core thermal power and the real-time current mean of the intermediate-range channel according to a linear instruction, thereby inferring the real-time core thermal power. The nuclear instrumentation system obtains the reactor thermal power mean value within a preset time period. A determination is made as to whether the power deviation between the mean power value and the real-time core thermal power meets a preset condition. If so, the protection setting is modified; if not, the protection setting remains unchanged. Therefore, the real-time core thermal power can be obtained from the real-time current mean value and the linear relationship. The power deviation between the real-time core thermal power and the power mean value is then used to determine whether the backup protection setting in the current backup protection is abnormal. This simplifies the method for verifying the deviation of the backup protection setting in the intermediate-range nuclear instrumentation system, avoids the risks associated with data switching, effectively improves data reliability, and thus significantly enhances the reliability of the reactor protection function and the safety of the nuclear power unit. This further ensures the orderly progress of production and improves the safety and reliability of equipment operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0033] Figure 1 The figure is a flow chart of a method for checking the deviation of a backup protection setting in one embodiment. DETAILED DESCRIPTION

[0034] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0035] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0036] The embodiment of the present invention provides a method for calibrating the backup protection fixed value deviation of the intermediate range of a nuclear instrument system. Figure 1 As shown, the following steps are included:

[0037] Obtain the real-time current average of the mid-range channel according to the acquisition instruction.

[0038] Specifically, the acquisition instruction can be issued in real time or executed on a scheduled basis. The real-time current values ​​of the mid-range channels of the nuclear instrumentation system are collected according to the acquisition time specified in the acquisition instruction. The acquired real-time current values ​​are then further processed to obtain the real-time current mean.

[0039] It should be noted that there may be multiple mid-range channels in the nuclear instrument system. In some embodiments, the real-time current average is the average of the real-time current values ​​of the multiple mid-range channels.

[0040] The linear relationship between the real-time core thermal power and the real-time current mean value of the intermediate range channel is obtained according to the linear instruction.

[0041] It can be understood that the linear relationship between the real-time core thermal power and the real-time current average can be obtained through a linear instruction to obtain a specific linear relationship, and the linear relationship between the two can also be calculated in real time based on historical core thermal power and current average data.

[0042] The real-time core thermal power is calculated based on the linear relationship and the real-time current average.

[0043] It can be understood that the calculated real-time core thermal power can be used for subsequent set value deviation calibration. The real-time core thermal power corresponds to the real-time current mean, but does not represent the thermal power of the current nuclear instrument system reactor. In some embodiments, the calculation process can be performed automatically without human intervention. By comparing the real-time core thermal power with the actual thermal power of the current nuclear instrument system reactor, it can be determined whether the current core operating status is safe. If the real-time core thermal power exceeds the preset protection set value, the system can issue an alarm signal to prompt the operator to take appropriate measures to avoid potential safety risks.

[0044] Get the average power value of the reactor thermal power of the core instrument system within a preset time period.

[0045] The power mean serves as the benchmark for subsequent calculations and comparisons. By statistically analyzing the reactor thermal power data within a preset time period, a relatively stable power mean can be obtained. This mean can reflect the average operating status of the reactor within that time period. In subsequent steps, this power mean will be compared with the calculated real-time core thermal power to determine whether there is any deviation in the core's operating status. It should be noted that the length of the preset time period can be adjusted according to actual conditions to ensure that the obtained power mean can accurately reflect the operating status of the reactor.

[0046] Determine whether the power deviation between the power mean and the real-time core thermal power meets the preset conditions; if the preset conditions are met, modify the protection setting; if not, maintain the protection setting at the current state.

[0047] Specifically, the power deviation value can be calculated by subtracting the power mean from the real-time core thermal power. This deviation value can intuitively reflect the fluctuation of the core thermal power. The preset conditions are usually set based on the operating experience and safety standards of the reactor, and it represents the acceptable range of core thermal power fluctuations. If the calculated power deviation value is within the preset conditions, it means that the current operating status of the core is relatively stable, but there may be a mismatch between the protection setting and the actual operating status due to factors such as reactor aging and environmental changes. At this time, the system can automatically or manually adjust the protection setting to ensure that it matches the actual thermal power of the current core.

[0048] The present invention timely discovers system abnormalities through the power deviation value between the power mean value and the real-time core thermal power, thereby improving the safety and stability of reactor operation.

[0049] In an executable embodiment, obtaining the real-time current average value of the intermediate range channel according to the acquisition instruction includes:

[0050] Get the preset interval duration from the collection instruction.

[0051] Specifically, the preset interval duration is set according to the operating characteristics of the reactor and the data collection requirements, which ensures that the collected current data can accurately reflect the average state of the intermediate range channel over a period of time.

[0052] Get the real-time current average value according to the preset interval length.

[0053] The real-time current average can accurately reflect the average current status of the intermediate range channel within the preset interval, providing a reliable basis for subsequent protection setting deviation verification. It can also avoid measurement deviation caused by a single intermediate range channel.

[0054] The real-time current average value is averaged according to the number of mid-range channels to obtain the real-time current average value.

[0055] In an executable embodiment, the preset interval duration is less than or equal to twenty minutes.

[0056] As you can understand, setting the interval to 20 minutes or less ensures that sufficient current data is acquired in a relatively short period of time to reflect the average state of the mid-range channels, while also preventing the loss of data timeliness caused by excessively long intervals. This setting improves system response speed while ensuring data accuracy, enabling timely detection of potential anomalies and ensuring safe reactor operation.

[0057] In one executable embodiment, obtaining the average power value of the reactor thermal power of the core instrument system in a preset time period includes:

[0058] Get the power average value that matches the preset interval length.

[0059] Specifically, all power values ​​of the reactor thermal power in the core instrumentation system over a preset interval are averaged to obtain a mean power value. This step allows the acquisition of power data corresponding to the real-time mean current value for subsequent protection setting deviation verification. By obtaining a power mean value consistent with the preset interval, the temporal consistency of current and power data is ensured, thereby improving the accuracy of the verification results.

[0060] In one executable embodiment, obtaining the average power value of the reactor thermal power of the core instrument system within a preset time period further includes:

[0061] The power mean is the total power of the mid-range channels averaged over the number of mid-range channels.

[0062] By averaging the total power, we can eliminate the impact of individual channel measurement errors on the final result, improving the accuracy and reliability of the average power value. Furthermore, correlating the average power value with the real-time average current value further verifies the rationality of the data and ensures the accuracy of subsequent protection setting deviation checks.

[0063] In one executable embodiment, obtaining a linear relationship between the real-time core thermal power and the real-time current mean value of the intermediate range channel according to the linear instruction includes:

[0064] According to the data interval requirements in the linear instruction, the historical current mean and historical core thermal power are obtained.

[0065] Based on the power formula principle, a linear relationship is established among the historical current mean, historical core thermal power, real-time current mean and real-time core thermal power.

[0066] By establishing this linear relationship, known historical data can be used to predict and verify the rationality of real-time data. Specifically, based on the linear relationship between historical current averages and historical core thermal power, the expected real-time core thermal power for a given real-time current average can be inferred. This inferred real-time core thermal power is then compared with the actual measured power average to determine the accuracy of the real-time data. If the difference between the two is within a preset error range, the real-time data is considered reasonable and can be used for subsequent fixed value deviation verification. If the difference exceeds the preset error range, the measurement equipment or measurement method may need to be calibrated or adjusted.

[0067] In one exemplary embodiment, the linear relationship is as follows:

[0068] The real-time core thermal power is the historical core thermal power multiplied by the ratio of the historical current average to the real-time current average.

[0069] The specific formula is as follows:

[0070]

[0071] Among them, n corresponds to the mid-range channel number; is the twenty-minute average value of the current of the mid-range channel numbered n; is the core thermal power of the intermediate range channel numbered n in the previous test condition; is the average current of the middle range channel with the working condition number n in the previous test, that is, the historical current mean; P RGL It is the twenty-minute average value of the reactor thermal power, that is, the mean power.

[0072] In an executable embodiment, the data interval requirement includes a historical current average value and a historical core thermal power acquired last time.

[0073] The historical current average and historical core thermal power data have been verified through actual operation, and their accuracy and reliability can be guaranteed.

[0074] In an executable embodiment, the preset condition includes: the power deviation value is greater than 1.5% of the full power.

[0075] In an executable embodiment, modifying the protection setting includes calculating an adjustment setting according to the power deviation value, and updating the backup protection setting to the adjustment setting.

[0076] The nuclear instrumentation system is also known as the RPN system. In one executable embodiment, the nuclear instrumentation system includes a newly added RPN intermediate-range backup protection in the intermediate-range signal processing cabinet of the nuclear instrumentation system, and the intermediate range has three channels. When any two channels of the three intermediate-range signals exceed the protection setting corresponding to 118% FP of the reactor power, a shutdown signal is generated. In order to ensure that the intermediate-range backup protection setting is consistent with the current value corresponding to 118% FP of the reactor power, the present invention is used to track the intermediate-range backup protection setting deviation (power deviation value). When the deviation exceeds 1.5% FP, the protection setting is calibrated.

[0077] The protection setting value RT exceeding 118% FP of the corresponding reactor power is as follows:

[0078]

[0079] Where, is the twenty-minute average value of the current of the middle range channel numbered n; P RGL It is the latest twenty-minute average value of the reactor thermal power, that is, the power mean.

[0080] In this embodiment, the present invention obtains the real-time current values ​​of the three channels of the RPN intermediate range through acquisition instructions every day when the reactor is in a stable state, and averages them to obtain the real-time current mean value.

[0081] The linear relationship between the historical current average of the three channels of the RPN intermediate range in the previous test condition and the historical core thermal power; the RGL system reactor thermal power value in the corresponding time period is obtained and averaged, that is, the power average is obtained.

[0082] Then calculate the corresponding core thermal power at this time, that is, the real-time core thermal power.

[0083] Continue to calculate the deviation (power deviation value) of the backup protection setting values ​​of the three channels in the RPN intermediate range, that is, the difference between the real-time core thermal power and the power average.

[0084] Next, determine whether the power deviation value is greater than 1.5% FP.

[0085] If the power deviation value is greater than 1.5% FP, the protection setting after RPN mid-range calibration is calculated and changed into the RPN system.

[0086] The above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it should not be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A method for calibrating the backup protection setting deviation of the intermediate range of a nuclear instrument system, characterized in that: The following steps are involved: Obtain the real-time current average value of the intermediate range channel according to the acquisition instruction; Acquire a linear relationship between the real-time core thermal power of the intermediate range channel and the real-time current mean value according to a linear instruction; Calculating the real-time core thermal power according to the linear relationship and the real-time current mean; Obtaining a power average value of the reactor thermal power of the nuclear instrument system within a preset time period; determining whether a power deviation value between the power mean value and the real-time core thermal power satisfies a preset condition; if the preset condition is satisfied, modifying the protection setting value; If not satisfied, the protection setting value remains the same.

2. The backup protection setting value deviation verification method according to claim 1, characterized in that: The step of obtaining the real-time current mean value of the intermediate range channel according to the acquisition instruction includes: Obtaining a preset interval duration from the acquisition instruction; Acquire the real-time current average value according to the preset interval duration; The real-time current mean value is averaged according to the number of the intermediate range channels to obtain the real-time current mean value.

3. The backup protection setting value deviation verification method according to claim 2, characterized in that: The preset interval duration is less than or equal to twenty minutes.

4. The backup protection setting value deviation verification method according to claim 2, characterized in that: The obtaining of the average power value of the reactor thermal power of the nuclear instrument system within a preset time period includes: Obtain the power mean value that is consistent with the preset interval duration.

5. The backup protection setting value deviation verification method according to claim 4, characterized in that: The step of obtaining the average thermal power of the reactor of the nuclear instrument system within a preset time period further includes: The power mean is obtained by averaging the total power of the mid-range channels according to the number of the mid-range channels.

6. The backup protection setting value deviation verification method according to claim 1, characterized in that: The step of obtaining the linear relationship between the real-time core thermal power of the intermediate range channel and the real-time current mean value according to the linear instruction includes: According to the data interval requirement in the linear instruction, a historical current average value and a historical core thermal power are obtained; The linear relationship among the historical current average, the historical core thermal power, the real-time current average and the real-time core thermal power is established based on the power formula principle.

7. The backup protection setting value deviation verification method according to claim 6, characterized in that: The linear relationship is as follows: The real-time core thermal power is the historical core thermal power multiplied by the ratio between the historical current average and the real-time current average.

8. The backup protection setting value deviation verification method according to claim 6, characterized in that: The data interval requirement includes the historical current average value and the historical core thermal power collected last time.

9. The backup protection setting value deviation verification method according to claim 1, characterized in that: The preset conditions include: the power deviation value is greater than 1.5% of the full power.

10. The backup protection setting value deviation verification method according to claim 1, characterized in that: The modifying of the protection constant includes calculating an adjustment constant according to the power deviation value, and updating the backup protection constant to the adjustment constant.

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