Main feed water valve fault detection method and device, computer equipment, readable storage medium and program product

Abstract

The invention relates to a main feed water valve fault detection method and device, computer equipment, a readable storage medium and a program product. The method comprises the following steps: when a nuclear power unit is in a starting state, acquiring a process quantity signal of the nuclear power unit; the process quantity signal comprises an opening signal and a flow signal of the main water supply valve and a water level signal of the evaporator; based on the process quantity signal, obtaining a fault detection value of the main water supply valve under a preset detection item; the preset detection items comprise a first detection item corresponding to the opening signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow signal and a fourth detection item corresponding to the opening signal and the water level signal; and under the condition that the fault detection values corresponding to all the preset detection items are preset values, determining that the main water supply valve fails. The method can accurately detect the fault of the main feed water valve.

Description

Technical Field

[0001] The present application relates to the technical field of evaporator control, and particularly to a method, device, computer device, readable storage medium and program product for detecting the failure of a main feed water valve. Background Art

[0002] The evaporator water level control system is one of the most important and sensitive control systems in a nuclear power plant, and its stability is directly related to the safe and stable operation of the nuclear power unit. As a key actuator of this system, the main feed water valve controls the evaporator water level by adjusting the feed water flow rate to ensure the normal operation of the steam generator. However, a failure of the main feed water valve may cause abnormal water level control, which may in turn lead to a unit transient or a reactor automatic shutdown.

[0003] The main feed water valve usually adopts a pneumatic control valve, and its common failure modes include two types: one is valve jamming, that is, the valve is stuck at a specific opening, and both the automatic and manual control functions fail; the other is valve out-of-control, that is, the valve is not controlled by the command signal and continuously opens or closes. Since the response time reserved for the operator after the failure of the main feed water valve is short, traditional failure detection methods are difficult to detect the failure of the main feed water valve in time. Summary of the Invention

[0004] Based on this, it is necessary to provide a method, device, computer device, readable storage medium and program product for detecting the failure of a main feed water valve, which can accurately detect the failure of the main feed water valve for the above technical problems.

[0005] In a first aspect, the present application provides a method for detecting the failure of a main feed water valve, including:

[0006] When the nuclear power unit is in a startup state, obtaining the process quantity signals of the nuclear power unit; the process quantity signals include the opening signal and flow signal of the main feed water valve, and the water level signal of the evaporator;

[0007] Based on the process quantity signals, obtaining the failure detection value of the main feed water valve under a preset detection item; the preset detection items include a first detection item corresponding to the opening signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow signal, and a fourth detection item corresponding to the opening signal and the water level signal;

[0008] When the failure detection values corresponding to all the preset detection items are preset values, determining that the main feed water valve fails.

[0009] In one embodiment, the nuclear power unit further includes an actuator; the process of obtaining the failure detection value of the main feed water valve under the first detection item based on the process quantity signals includes:

[0010] Obtaining the actual opening corresponding to the opening signal of the main feed water valve;

[0011] Obtain the secondary circuit load of the nuclear power unit and determine the required opening corresponding to the secondary circuit load;

[0012] When the absolute value of the valve position deviation between the actual opening and the required opening is not less than the first preset value, determine that the fault detection value of the main feed water valve under the first detection item is the preset value; the first preset value is determined according to the calculation uncertainty of the required opening, the detection uncertainty of the opening signal, and the adjustment uncertainty of the actuator.

[0013] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the second detection item based on the process quantity signal includes:

[0014] Obtain the water level change rate within a preset time period according to the water level signal; the preset time period is determined according to the water level adjustment period of the evaporator;

[0015] When the absolute value of the water level change rate is not less than the second preset value, determine that the fault detection value of the main feed water valve under the second detection item is the preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches the preset value.

[0016] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the third detection item based on the process quantity signal includes:

[0017] Obtain the actual feed water flow corresponding to the flow signal and the required feed water flow corresponding to the secondary circuit load;

[0018] When the absolute value of the flow deviation between the actual feed water flow and the required feed water flow is not less than the third preset value, determine that the fault detection value of the main feed water valve under the third detection item is the preset value; the third preset value is determined according to the detection uncertainty of the flow signal, the calculation uncertainty of the required feed water flow, and the preset feed water flow deviation amount.

[0019] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the fourth detection item based on the process quantity signal includes:

[0020] Obtain the first change rate corresponding to the opening signal and the second change rate corresponding to the water level signal within the water level adjustment period of the evaporator;

[0021] When the absolute value of the difference between the first change rate and the second change rate is greater than the absolute value, determine that the fault detection value of the main feed water valve under the fourth detection item is the preset value.

[0022] In one embodiment, the nuclear power unit further includes a main feed water pump; the method further includes:

[0023] When it is determined that the main feed water valve fails, obtain the set speed of the main feed water pump, and control the operation of the main feed water pump according to the set speed to adjust the main feed water flow of the evaporator so that the water level of the evaporator is within a preset adjustment range.

[0024] In a second aspect, the present application also provides a main feed water valve fault detection device, including:

[0025] A signal acquisition module, configured to obtain process quantity signals of the nuclear power unit when the nuclear power unit is in a startup state; the process quantity signals include the opening signal and the flow signal of the main feed water valve, and the water level signal of the evaporator;

[0026] A fault detection module, configured to obtain a fault detection value of the main feed water valve under a preset detection item based on the process quantity signals; the preset detection items include a first detection item corresponding to the opening signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow signal, and a fourth detection item corresponding to the opening signal and the water level signal;

[0027] A fault determination module, configured to determine that the main feed water valve fails when the fault detection values corresponding to all the preset detection items are preset values.

[0028] In a third aspect, the present application also provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the method steps of any one of the first aspect are implemented.

[0029] In a fourth aspect, the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method steps of any one of the first aspect are implemented.

[0030] In a fifth aspect, the present application also provides a computer program product, including a computer program, and when the computer program is executed by a processor, the method steps of any one of the first aspect are implemented.

[0031] The above-mentioned main feed water valve fault detection method, device, computer device, readable storage medium and program product can timely detect the main feed water valve fault by obtaining the process quantity signals of the nuclear power unit when the nuclear power unit is in a startup state, obtaining the fault detection value of the main feed water valve under the preset detection item based on the process quantity signals, and determining that the main feed water valve fails when the fault detection values corresponding to all the preset detection items are preset values, effectively avoiding the problem of out-of-control water level of the evaporator caused by the main feed water valve fault, and improving the accuracy of the main feed water valve fault component through multi-dimensional detection. Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the accompanying drawings required for the description in the embodiments of the present application or the related art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0033] Figure 1 It is the evaporator water level control logic diagram in one embodiment;

[0034] Figure 2 It is the process variable response curve diagram of nuclear power unit A in one embodiment;

[0035] Figure 3 It is the process variable response curve diagram of nuclear power unit B in one embodiment;

[0036] Figure 4 It is the schematic diagram of the automatic control process in the failure mode of the main feed water valve in one embodiment;

[0037] Figure 5 It is the schematic diagram of the process of the main feed water valve failure detection method in one embodiment;

[0038] Figure 6 It is the schematic diagram of the functional relationship between the secondary loop load and the main feed water valve opening in one embodiment;

[0039] Figure 7 It is the schematic diagram of the functional relationship between the secondary loop load and the main feed water flow rate in one embodiment;

[0040] Figure 8 It is the schematic diagram of the process of the main feed water valve failure detection method in another embodiment;

[0041] Figure 9 It is the structural block diagram of the main feed water valve failure detection device in one embodiment;

[0042] Figure 10 It is the internal structure diagram of a computer device in one embodiment. Detailed implementation manners

[0043] In order to make the purpose, technical solutions and advantages of the present application clearer, the following further details the present application in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] In a nuclear power unit, the evaporator (i.e., the steam generator) is a key hub connecting the nuclear reactor and the steam turbine generator set. The two are closely dependent on each other, jointly promoting the efficient conversion of nuclear energy into electrical energy. The operating principle of the evaporator is based on the flow of reactor coolant in the heat transfer tubes, transferring heat to the secondary circuit water outside the tubes, promoting the natural circulation of the secondary circuit water inside the steam generator, and then converting part of the water flowing outside the heat transfer tubes into saturated steam to supply the main steam turbine and various auxiliary facilities, ensuring the stable operation of the entire system.

[0045] However, during the actual operation of the steam generator, maintaining the stability of the water level on the secondary side of the steam generator has become a highly challenging task. Fluctuations in the water level on the secondary side of the steam generator can cause many serious problems: on the one hand, too high a water level may lead to deterioration of the steam-water separation effect, exacerbating the phenomenon of steam carrying water. This will not only reduce the steam quality and affect the work efficiency of the main steam turbine, but also may cause erosion damage to the turbine blades over a long period of time, significantly shortening the service life of the steam turbine, increasing the equipment maintenance cost and the risk of shutdown for maintenance; on the other hand, too low a water level may expose part of the heat transfer tubes, causing local overheating of the heat transfer tubes, seriously endangering the structural integrity of the heat transfer tubes, and even triggering leakage accidents, threatening the safe operation of the entire device. At the same time, it will also affect the normal power supply or energy supply of the system due to insufficient steam production.

[0046] When maintaining the stability of the water level on the secondary side of the steam generator, the traditional methods mainly focus on the water level control of the evaporator, which includes two key aspects: the control of the main feed pump speed and the control of the main feed water valve opening.

[0047] Specifically, in the main feed pump speed control link, its core purpose is to accurately adjust the feed water flow while ensuring that the pressure drop of the regulating valve can always be maintained at a constant state. At the same time, in order to adapt to the dynamic changes of the system load, it is also necessary to ensure that the pressure difference between the main pipe and the steam main pipe (i.e., the steam-water pressure difference) can show a specific parabolic change law with the load change. During this process, the main feed pump, as the actuator, shoulders the heavy responsibility of precise regulation. The quality of its operating performance is directly related to the accuracy and timeliness of the feed water regulation. However, the existing main feed pump speed control strategies still have limitations in dealing with complex working condition changes and meeting the high-precision water level control requirements, and it is difficult to achieve the ideal dynamic matching of the steam-water pressure difference.

[0048] For the control of the main feed water valve opening, since each steam generator is equipped with an independent water level regulation system, currently, the opening of the main feed water valve is mainly changed manually or automatically to change the feed water flow rate, thereby controlling the water level of the evaporator. In this process, the main feed water valve (main valve) and the bypass feed water valve (bypass valve) act as actuators. However, when the traditional main feed water valve opening control method faces complex working conditions such as rapid load changes and water quality fluctuations, the adjustment response speed is slow, and overshoot or undershoot phenomena are likely to occur, resulting in the difficulty of meeting the increasingly high industrial production requirements for water level control accuracy. Moreover, there is also a lack of an efficient optimization mechanism for the coordinated cooperation between different valves.

[0049] In summary, when the traditional steam generator water level regulation technology faces complex and changeable operating conditions, whether it is the main feed water pump speed control or the main feed water valve opening control, there are many deficiencies, making it difficult to ensure that the secondary side water level of the steam generator is always stable at the required set value, which greatly restricts the efficient and safe development of related industries.

[0050] Based on this, the embodiment of the present application provides a main feed water valve fault detection method. By the response characteristics of process variables in the main feed water valve fault mode, the main feed water valve fault is automatically judged, improving the accuracy of fault judgment, effectively making up for the deficiencies of traditional methods, and then effectively realizing the steam generator water level regulation in the main feed water valve fault mode, enhancing the operation stability and reliability of the steam generator, thereby ensuring the stable operation of the nuclear power unit.

[0051] In an exemplary embodiment, as Figure 1 shown, the evaporator water level control mainly includes the main feed water valve opening control and the main feed water pump speed control. Its control system is mainly composed of components such as the evaporator, the main feed water pump, the main feed water valve, and the corresponding pipelines. As Figure 1 shown, where is the steam-water pressure difference, is the steam flow rate, is the steam pressure, is the feed water flow rate, is the evaporator water level, is the evaporator water level set value, is the wide range of the secondary loop impression load, is the feed water temperature, is the narrow range of the secondary loop impression load, is the main feed water valve opening signal, is the bypass valve opening signal, is the feed water pump speed.

[0052] Optionally, for each steam generator, an independent water level regulating system is set up to control the water level of the evaporator by changing the opening of the main feed water valve to change the feed water flow rate. The actuators are the main feed water valve (referred to as the main valve) and the bypass feed water valve (referred to as the bypass valve). The main purpose of the main feed water pump speed control is to regulate the feed water while maintaining the constant pressure drop of the regulating valve; the pressure difference between the main pipe and the steam main pipe

[0053] Exemplarily, for the main feed water valve failure, typical failure data is selected for analysis, and the process variable response curves in the main feed water valve failure mode as shown in Figure 2 and Figure 3 are obtained. Among them, Figure 2 and Figure 3 are the process variable response curves in the main feed water valve failure mode that actually occurred in nuclear power unit A and nuclear power unit B respectively.

[0054] From Figure 2 and Figure 3 , it can be seen that after the main feed water valve fails, because the actual opening of the main feed water valve is smaller than the required opening , and the steam-water pressure difference basically remains unchanged, resulting in a decrease in the feed water flow rate, and the water level of the evaporator continuously drops, and the deviation between the water level of the evaporator and the set value of the evaporator water level gradually expands. The main feed water valve opening demand signal continuously opens under the integral action of the regulating system and reaches the maximum opening of 100%. Since the actual opening of the main feed water valve does not actually change, if no intervention measures are taken, it will directly trigger the reactor protection logic of the evaporator water level. As shown in Figure 3 , nuclear power unit B triggered the reactor automatic shutdown signal.

[0055] Exemplarily, as shown in Figure 4 , Figure 4 is the schematic diagram of the automatic control process in the main feed water valve failure mode. When the main feed water valve fails, the actual opening of the main feed water valve may be smaller than the required opening, and may also be larger. Therefore, the main feed water valve opening demand signal continuously opens or closes under the integral action of the regulating system. The choice of the opening or closing direction is related to the steam-water deviation at the moment of valve jamming. The water level of the evaporator There are also significant differences in the rate of change. To prevent large fluctuations in the evaporator water level and trigger the reactor protection logic in the event of a main feed water valve failure, the evaporator water level is effectively controlled through three parts: automatic judgment of the main feed water valve failure, setting the speed of the feed water pump in the main feed water valve failure mode, and automatic control in the main feed water valve failure mode.

[0056] Specifically, the automatic judgment of the main feed water valve failure mainly judges the failure of the main feed water valve through process quantity signals, including the opening degree of the main feed water valve, the evaporator water level, the feed water flow, etc. When the main feed water valve fails, preset the speed of the feed water pump, automatically adjust the speed of the feed water pump, control the evaporator water level of the failed main feed water valve loop, control the evaporator water level of the normal loop, etc., to achieve the stable operation of the evaporator water levels of the three nuclear power units.

[0057] In an exemplary embodiment, as Figure 5 shown, a method for detecting the failure of the main feed water valve is provided, including the following steps 502 to step 506. Among them:

[0058] S502: When the nuclear power unit is in the startup state, obtain the process quantity signals of the nuclear power unit; the process quantity signals include the opening degree signal and the flow signal of the main feed water valve, and the water level signal of the evaporator.

[0059] Optionally, during the startup of the nuclear power unit, obtain the process quantity signals of the nuclear power unit, including the opening degree signal and the flow signal of the main feed water valve, and the water level signal of the evaporator. Among them, the opening degree signal of the main feed water valve represents the current opening degree of the main valve, is directly related to the feed water flow, and determines the amount of water entering the evaporator. The flow signal reflects the actual water flow passing through the main feed water valve and is the direct basis for judging whether the feed water meets the operation requirements. The water level signal of the evaporator provides a basis for judging whether the evaporator is operating normally. When the water level is too high or too low, it will have a serious impact on the operation of the nuclear power unit.

[0060] S504: Based on the process quantity signals, obtain the failure detection value of the main feed water valve under the preset detection items; the preset detection items include the first detection item corresponding to the opening degree signal, the second detection item corresponding to the water level signal, the third detection item corresponding to the flow signal, and the fourth detection item corresponding to the opening degree signal and the water level signal.

[0061] Optionally, based on the process quantity signal, fault detection of the main feed water valve is performed from multiple aspects. Among them, the first detection item corresponds to the opening signal. By deeply analyzing the opening signal, it is determined whether the opening change rate is abnormal, etc. The second detection item corresponds to the water level signal. By combining the evaporator water level signal, the change trend of the water level and the collaborative relationship with the opening of the main feed water valve and the feed water flow can be determined. The third detection item corresponds to the flow signal, focusing on the characteristics of the flow signal itself, and detecting whether the flow is stable, etc. The fourth detection item corresponds to the opening and water level signals, comprehensively considering the dynamic coupling relationship between the opening signal and the water level signal, and determining whether the action of the main feed water valve effectively acts on the evaporator water level control.

[0062] S506: When the fault detection values corresponding to all preset detection items are preset values, it is determined that the main feed water valve has a fault.

[0063] Optionally, when the fault detection values corresponding to all preset detection items are preset values, it means that abnormalities are detected from multiple dimensions, and then it is determined that the main feed water valve has a fault, ensuring the reliability of the fault determination. Exemplarily, the preset value can be 1, representing that the fault of the corresponding preset detection item is true. When the faults corresponding to all preset detection items are true, it is determined that the main feed water valve has a fault.

[0064] In the above method for fault detection of the main feed water valve, when the nuclear power unit is in the startup state, the process quantity signal of the nuclear power unit is acquired. Based on the process quantity signal, the fault detection value of the main feed water valve under the preset detection items is obtained. When the fault detection values corresponding to all preset detection items are preset values, it is determined that the main feed water valve has a fault, which can timely detect the fault of the main feed water valve, effectively avoid the problem of out-of-control evaporator water level caused by the fault of the main feed water valve, and improve the accuracy of the main feed water valve fault component through multi-dimensional detection.

[0065] In an exemplary embodiment, the nuclear power unit further includes an actuator; the process of obtaining the fault detection value of the main feed water valve under the first detection item based on the process quantity signal includes: obtaining the actual opening corresponding to the opening signal of the main feed water valve; obtaining the secondary circuit load of the nuclear power unit and determining the required opening corresponding to the secondary circuit load; when the absolute value of the valve position deviation between the actual opening and the required opening is not less than the first preset value, determining that the fault detection value of the main feed water valve under the first detection item is the preset value; the first preset value is determined according to the calculation uncertainty of the required opening, the detection uncertainty of the opening signal, and the adjustment uncertainty of the actuator.

[0066] Optionally, when the main water supply valve fails, the fluctuation form of the main water supply valve opening signal will change. At this time, the main water supply valve opening signal deviates from the fluctuation range during normal operation and continues to change in one direction, that is, the main water supply valve opening signal continues to deviate from the normal opening demand signal. Based on this, by obtaining the actual opening corresponding to the opening signal of the main water supply valve and comparing it with the demand opening corresponding to the secondary circuit load, if the actual opening continues to deviate from the normal range of the demand opening, it means that the main water supply valve is faulty according to the opening signal.

[0067] Exemplary, combined Figure 1 It can be obtained that if the main water supply valve opening If the opening degree deviates from the opening corresponding to the load of the second circuit and meets a certain threshold, the fault detection value of the main water supply valve under the first detection item is the preset value. The specific judgment formula is:

[0068]

[0069]

[0070] in, Second circuit load The corresponding main water supply valve opening; Second circuit load Corresponding main water supply valve opening Functional relationship; Main water supply valve opening deviation threshold.

[0071] For example, the secondary circuit load Corresponding main water supply valve opening The functional relationship is as follows Figure 6 As shown, Figure 6 middle The secondary circuit load is narrow range when the main water supply valve is opened The value of for Secondary circuit load wide range Since the main water supply valve opening signal is directly related to the secondary circuit load, the main water supply valve opening represented by the secondary circuit load has reference and accuracy. Among them, the main water supply valve opening deviation threshold It consists of three parts, namely the secondary circuit load Corresponding main water supply valve opening The uncertainty of the main water supply valve opening signal during regulation and the uncertainty of the actuator.

[0072] In this embodiment, by obtaining the fault detection value of the main water supply valve under the first detection item based on the deviation between the actual opening corresponding to the opening signal and the required opening corresponding to the secondary circuit load, the main water supply valve fault can be accurately detected based on the main water supply valve opening.

[0073] In an exemplary embodiment, the process of obtaining the fault detection value of the main feed water valve under the second detection item based on the process quantity signal includes: obtaining the water level change rate within a preset time period according to the water level signal; the preset time period is determined according to the water level regulation period of the evaporator; when the absolute value of the water level change rate is not less than a second preset value, determining that the fault detection value of the main feed water valve under the second detection item is a preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches the preset value.

[0074] Optionally, when the main feed water valve fails, there is a difference between the actual opening degree and the required opening degree of the main feed water valve, and moreover, there will also be a deviation between the evaporator water level and the set value of the evaporator water level. For example, the evaporator water level will continuously change in the rising or falling direction.

[0075] Exemplarily, combined with Figure 1 it can be obtained that whether the main feed water valve fails can be judged by the water level change rate of the evaporator within a certain period. When the water level change rate of the evaporator within the period exceeds the preset value the water level of the evaporator within the period then it is determined that the fault detection value of the main feed water valve under the second detection item is a preset value. The specific judgment formula is: wherein,

[0076]

[0077] wherein, T is the water level regulation period of the evaporator, is the threshold value of the evaporator water level change rate.

[0078] Optionally, during normal operation, the opening degree signal of the main feed water valve presents a small-amplitude oscillation process in a sine wave form. In order to prevent the small rise or fall of the evaporator water level during the regulation process from causing the water level change rate of the evaporator to exceed the preset value and avoid interference to the judgment process, it is filtered by setting a period. In some embodiments, the evaporator water level change rate threshold is the value of the evaporator water level change rate when the opening degree signal of the main feed water valve deviates from the normal value by 3%.

[0079] In this embodiment, by obtaining the fault detection value of the main feed water valve under the second detection item according to the water level change rate of the evaporator, the fault of the main feed water valve can be accurately detected based on the water level change.

[0080] In an exemplary embodiment, the process of obtaining the fault detection value of the main feed water valve under the third detection item based on the process quantity signal includes: obtaining the actual feed water flow corresponding to the flow signal, and obtaining the required feed water flow corresponding to the secondary circuit load; when the absolute value of the flow deviation between the actual feed water flow and the required feed water flow is not less than the third preset value, determining the fault detection value of the main feed water valve under the third detection item as the preset value; the third preset value is determined according to the detection uncertainty of the flow signal, the calculation uncertainty of the required feed water flow, and the preset feed water flow deviation amount.

[0081] Optionally, when the main feed water valve fails, there is a difference between the actual opening degree of the main feed water valve and the required opening degree, and the steam-water pressure difference is adjusted by the speed of the feed water pump, which is independent of the main feed water valve regulation system. Therefore, the feed water flow is deviated compared with the normal operation period.

[0082] Exemplarily, combined with Figure 1 it can be obtained that within the evaporator water level regulation period T, when the feed water flow deviates from the main feed water flow corresponding to the secondary circuit load and meets a certain threshold then it is determined that the fault detection value of the main feed water valve under the third detection item is the preset value. The specific judgment formula is:

[0083]

[0084]

[0085] Wherein, is the main feed water flow corresponding to the secondary circuit load , is the function relationship between the secondary circuit load and the main feed water flow , is the main feed water flow deviation threshold.

[0086] Optionally, in order to ensure the accuracy of the correspondence between the secondary circuit load and the main feed water flow , it is obtained by fitting with a unary high-order function. As shown in Figure 7 , wherein, is the value of the main feed water flow corresponding to when the secondary circuit load is 0; is the value of the main feed water flow corresponding to when the secondary circuit load is . The main feed water flow deviation threshold consists of three parts: the uncertainty of the main feed water flow measurement, the uncertainty of the main feed water flow corresponding to the secondary circuit load and the setting of the main feed water flow deviation amount.

[0087] In this embodiment, by obtaining the fault detection value of the main feed water valve under the third detection item according to the flow deviation between the actual feed water flow corresponding to the flow signal and the required feed water flow, the fault of the main feed water valve can be accurately detected based on the change of the feed water flow.

[0088] In an exemplary embodiment, the process of obtaining the fault detection value of the main feed water valve under the fourth detection item based on the process quantity signal includes: obtaining the first change rate corresponding to the opening signal and the second change rate corresponding to the water level signal within the water level adjustment period of the evaporator; when the absolute value of the difference between the first change rate and the second change rate is greater than a certain absolute value, determining that the fault detection value of the main feed water valve under the fourth detection item is a preset value.

[0089] Optionally, when the main feed water valve fails, its normal adjustment function will be affected. If the main feed water valve cannot be normally closed or closed smaller, too much water will enter the evaporator, causing the water level of the evaporator to continue to rise; conversely, if the main feed water valve cannot be normally opened or opened larger, the feed water flow is insufficient, and the water level of the evaporator will continue to drop. When the water level control system of the evaporator detects that the water level deviates from the set value, it will change the feed water flow by adjusting the opening of the main feed water valve to correct the water level deviation. However, when there is a problem with the actuator of the main feed water valve, although the control system issues an adjustment command, the main feed water valve cannot execute correctly, resulting in the water level continuing to change in the direction of deviating from the set value. At this time, the situation where the change trend of the evaporator water level is opposite to the change trend of the main feed water valve opening signal will occur.

[0090] Exemplarily, combined with Figure 1 it can be obtained that within the water level adjustment period T of the evaporator, when the change trend of the evaporator water level is opposite to the change trend of the main feed water valve opening signal, it is determined that the fault detection value of the main feed water valve under the fourth detection item is a preset value. The specific judgment formula is:

[0091]

[0092] By performing differential operations on the evaporator water level and the main feed water valve opening signal to achieve the judgment of its increasing and decreasing directions.

[0093] Exemplarily, if the change trend of the evaporator water level is opposite to the change trend of the main feed water valve opening signal , the above equation holds, and the fault detection value is 1; if the change trend of the evaporator water level is the same as the change trend of the main feed water valve opening signal , the above equation does not hold, and the fault detection value is 0.

[0094] In this embodiment, by obtaining the fault detection value of the main feed water valve under the fourth detection item according to the correlation between the change trend of the evaporator water level and the change trend of the main feed water valve opening, the fault of the main feed water valve can be accurately detected.

[0095] In an exemplary embodiment, the nuclear power unit further includes a main feed water pump; the method further includes: when it is determined that the main feed water valve fails, obtaining the set speed of the main feed water pump, and controlling the operation of the main feed water pump according to the set speed to adjust the main feed water flow of the evaporator so that the water level of the evaporator is within a preset adjustment range.

[0096] Optionally, after it is determined that the main feed water valve fails, first, the set speed information of the main feed water pump needs to be obtained. As another key component in the feed water system of the evaporator of the nuclear power unit, its speed directly determines the size of the feed water flow and has a crucial impact on the evaporator water level. According to the obtained set speed of the main feed water pump, accurately control the main feed water pump to operate at this set speed. Since there is a clear functional relationship between the speed of the main feed water pump and the feed water flow, by precisely regulating the speed of the main feed water pump, the effective adjustment of the main feed water flow of the evaporator is realized, and then the water level of the evaporator is gradually stabilized within the preset adjustment range.

[0097] In this embodiment, by accurately detecting the fault of the main feed water valve, when the main feed water valve fails, obtaining the set speed of the main feed water pump, and controlling the operation of the main feed water pump according to the set speed so that the water level of the evaporator is within the preset adjustment range, the stable operation of the nuclear power unit can be effectively guaranteed.

[0098] In an exemplary embodiment, as Figure 8 shown, a method for detecting the fault of the main feed water valve is provided, and the method includes the following steps:

[0099] When the nuclear power unit is in the startup state, obtain the process quantity signals of the nuclear power unit; the process quantity signals include the opening signal and flow signal of the main feed water valve, and the water level signal of the evaporator. Among them, the nuclear power unit further includes an actuator.

[0100] (1) Valve position deviation judgment: Obtain the actual opening corresponding to the opening signal of the main feed water valve; obtain the secondary circuit load of the nuclear power unit, and determine the required opening corresponding to the secondary circuit load; when the absolute value of the valve position deviation between the actual opening and the required opening is not less than the first preset value, determine that the fault detection value of the main feed water valve under the first detection item is the preset value; the first preset value is determined according to the calculation uncertainty of the required opening, the detection uncertainty of the opening signal, and the adjustment uncertainty of the actuator.

[0101] (2) Water level trend judgment: Obtain the water level change rate within a preset time period according to the water level signal; the preset time period is determined according to the water level adjustment cycle of the evaporator; when the absolute value of the water level change rate is not less than the second preset value, determine that the fault detection value of the main feed water valve under the second detection item is the preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches the preset value.

[0102] (3) Main feed water flow deviation judgment: Obtain the actual feed water flow corresponding to the flow signal, and obtain the required feed water flow corresponding to the secondary circuit load; when the absolute value of the flow deviation between the actual feed water flow and the required feed water flow is not less than the third preset value, determine that the fault detection value of the main feed water valve under the third detection item is the preset value; the third preset value is determined according to the detection uncertainty of the flow signal, the calculation uncertainty of the required feed water flow, and the preset feed water flow deviation.

[0103] (4) Water level regulation characteristic judgment: Obtain the first change rate corresponding to the opening signal and the second change rate corresponding to the water level signal within the water level adjustment cycle of the evaporator; when the absolute value of the difference between the first change rate and the second change rate is greater than and the absolute value of, determine that the fault detection value of the main feed water valve under the fourth detection item is the preset value.

[0104] (5) Through the AND gate operation of the four judgment logics, finally output the judgment result. If the outputs of the main feed water flow deviation judgment, water level trend judgment, valve position deviation judgment, and water level regulation characteristic judgment are all preset values, that is, all meet the judgment conditions, then automatically output the main feed water valve fault signal: Obtain the first change rate corresponding to the opening signal and the second change rate corresponding to the water level signal within the water level adjustment cycle of the evaporator; when the absolute value of the difference between the first change rate and the second change rate is greater than and the absolute value of, determine that the fault detection value of the main feed water valve under the fourth detection item is the preset value. When the fault detection values corresponding to all preset detection items are preset values, determine that the main feed water valve is faulty. Among them, the nuclear power unit also includes a main feed water pump. When it is determined that the main feed water valve is faulty, obtain the set speed of the main feed water pump, and control the operation of the main feed water pump according to the set speed to adjust the main feed water flow of the evaporator so that the water level of the evaporator is within the preset adjustment range.

[0105] In this embodiment, by obtaining the process quantity signal of the nuclear power unit when the nuclear power unit is in the startup state, and based on the process quantity signal, obtaining the fault detection value of the main feed water valve under the preset detection item, when the fault detection values corresponding to all preset detection items are preset values, determining that the main feed water valve is faulty, it can detect the main feed water valve fault in time, effectively avoid the problem of out-of-control water level of the evaporator caused by the main feed water valve fault, and can improve the accuracy of the main feed water valve fault parts through multi-dimensional detection.

[0106] It should be understood that although the steps in the flowcharts involved in the above embodiments are shown in sequence according to the indications of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0107] Based on the same inventive concept, an embodiment of the present application also provides a main feed water valve fault detection device for implementing the main feed water valve fault detection method involved above. The implementation solutions provided by this device to solve problems are similar to the implementation solutions recorded in the above method. Therefore, the specific limitations in one or more embodiments of the main feed water valve fault detection device provided below can refer to the limitations on the main feed water valve fault detection method in the above text, and will not be repeated here.

[0108] In an exemplary embodiment, as Figure 9 shown, a main feed water valve fault detection device is provided, including: a signal acquisition module 10, a fault detection module 20, and a fault determination module 30, where:

[0109] The signal acquisition module 10 is configured to acquire the process quantity signals of the nuclear power unit when the nuclear power unit is in a startup state; the process quantity signals include the opening signal and the flow signal of the main feed water valve, and the water level signal of the evaporator.

[0110] The fault detection module 20 is configured to obtain the fault detection value of the main feed water valve under a preset detection item based on the process quantity signals; the preset detection items include a first detection item corresponding to the opening signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow signal, and a fourth detection item corresponding to the opening signal and the water level signal.

[0111] The fault determination module 30 is configured to determine that the main feed water valve is faulty when the fault detection values corresponding to all the preset detection items are preset values.

[0112] In an exemplary embodiment, the nuclear power unit further includes an actuator; the fault detection module 20 is further configured to obtain the actual opening corresponding to the opening signal of the main feed water valve; obtain the secondary circuit load of the nuclear power unit, and determine the required opening corresponding to the secondary circuit load; when the absolute value of the valve position deviation between the actual opening and the required opening is not less than a first preset value, determine that the fault detection value of the main feed water valve under the first detection item is a preset value; the first preset value is determined according to the calculation uncertainty of the required opening, the detection uncertainty of the opening signal, and the adjustment uncertainty of the actuator.

[0113] In an exemplary embodiment, the fault detection module 20 is further configured to obtain the water level change rate within a preset time period according to the water level signal; the preset time period is determined according to the water level adjustment period of the evaporator; when the absolute value of the water level change rate is not less than a second preset value, determine that the fault detection value of the main feed water valve under the second detection item is a preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches the preset value.

[0114] In an exemplary embodiment, the fault detection module 20 is further configured to obtain the actual feed water flow corresponding to the flow signal, and obtain the required feed water flow corresponding to the secondary circuit load; when the absolute value of the flow deviation between the actual feed water flow and the required feed water flow is not less than a third preset value, determine that the fault detection value of the main feed water valve under the third detection item is a preset value; the third preset value is determined according to the detection uncertainty of the flow signal, the calculation uncertainty of the required feed water flow, and a preset feed water flow deviation amount.

[0115] In an exemplary embodiment, the fault detection module 20 is further configured to obtain a first change rate corresponding to the opening signal and a second change rate corresponding to the water level signal within the water level adjustment period of the evaporator; when the absolute value of the difference between the first change rate and the second change rate is greater than the absolute value of, determine that the fault detection value of the main feed water valve under the fourth detection item is a preset value.

[0116] In an exemplary embodiment, the nuclear power unit further includes a main feed water pump; the fault determination module 30 is further configured to, when it is determined that the main feed water valve fails, obtain the set speed of the main feed water pump, and control the operation of the main feed water pump according to the set speed to adjust the main feed water flow of the evaporator so that the water level of the evaporator is within a preset adjustment range.

[0117] Each module in the above-mentioned main feed water valve fault detection device can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0118] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structural diagram may be as shown in Figure 10 . The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a main feed water valve fault detection method. The display unit of the computer device is used to form a visually visible picture, which may be a display screen, a projection device, or a virtual reality imaging device. The display screen may be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device may be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the housing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0119] Those skilled in the art can understand that Figure 10 the structure shown in is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0120] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the following steps are implemented: when the nuclear power unit is in a startup state, obtain the process quantity signals of the nuclear power unit; the process quantity signals include the opening signal and flow signal of the main feed water valve, and the water level signal of the evaporator; based on the process quantity signals, obtain the fault detection value of the main feed water valve under preset detection items; the preset detection items include a first detection item corresponding to the opening signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow signal, and a fourth detection item corresponding to the opening signal and the water level signal; when the fault detection values corresponding to all the preset detection items are preset values, determine that the main feed water valve is faulty.

[0121] In one embodiment, the nuclear power unit further includes an actuator; the process of obtaining the fault detection value of the main feed water valve under the first detection item based on the process quantity signal when the processor executes the computer program includes: obtaining the actual opening degree corresponding to the opening degree signal of the main feed water valve; obtaining the secondary circuit load of the nuclear power unit and determining the required opening degree corresponding to the secondary circuit load; when the absolute value of the valve position deviation between the actual opening degree and the required opening degree is not less than a first preset value, determining that the fault detection value of the main feed water valve under the first detection item is a preset value; the first preset value is determined according to the calculation uncertainty of the required opening degree, the detection uncertainty of the opening degree signal, and the adjustment uncertainty of the actuator.

[0122] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the second detection item based on the process quantity signal when the processor executes the computer program includes: obtaining the water level change rate within a preset time period according to the water level signal; the preset time period is determined according to the water level adjustment period of the evaporator; when the absolute value of the water level change rate is not less than a second preset value, determining that the fault detection value of the main feed water valve under the second detection item is a preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches the preset value.

[0123] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the third detection item based on the process quantity signal when the processor executes the computer program includes: obtaining the actual feed water flow rate corresponding to the flow rate signal and obtaining the required feed water flow rate corresponding to the secondary circuit load; when the absolute value of the flow rate deviation between the actual feed water flow rate and the required feed water flow rate is not less than a third preset value, determining that the fault detection value of the main feed water valve under the third detection item is a preset value; the third preset value is determined according to the detection uncertainty of the flow rate signal, the calculation uncertainty of the required feed water flow rate, and a preset feed water flow rate deviation amount.

[0124] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the fourth detection item based on the process quantity signal when the processor executes the computer program includes: obtaining a first change rate corresponding to the opening degree signal and a second change rate corresponding to the water level signal within the water level adjustment period of the evaporator; when the absolute value of the difference between the first change rate and the second change rate is greater than a certain absolute value, determining that the fault detection value of the main feed water valve under the fourth detection item is a preset value.

[0125] In one embodiment, the nuclear power unit further includes a main feed water pump; when the processor executes the computer program, the following steps are further implemented: when it is determined that the main feed water valve fails, obtaining the set speed of the main feed water pump and controlling the operation of the main feed water pump according to the set speed to adjust the main feed water flow rate of the evaporator so that the water level of the evaporator is within a preset adjustment range.

[0126] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented: when the nuclear power unit is in a startup state, obtain the process quantity signals of the nuclear power unit; the process quantity signals include the opening degree signal and the flow rate signal of the main feed water valve, and the water level signal of the evaporator; based on the process quantity signals, obtain the fault detection value of the main feed water valve under a preset detection item; the preset detection items include a first detection item corresponding to the opening degree signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow rate signal, and a fourth detection item corresponding to the opening degree signal and the water level signal; when the fault detection values corresponding to all the preset detection items are preset values, determine that the main feed water valve is faulty.

[0127] In one embodiment, the nuclear power unit further includes an actuator; the process of obtaining the fault detection value of the main feed water valve under the first detection item based on the process quantity signals when the computer program is executed by the processor includes: obtaining the actual opening degree corresponding to the opening degree signal of the main feed water valve; obtaining the secondary circuit load of the nuclear power unit, and determining the required opening degree corresponding to the secondary circuit load; when the absolute value of the valve position deviation between the actual opening degree and the required opening degree is not less than a first preset value, determine that the fault detection value of the main feed water valve under the first detection item is a preset value; the first preset value is determined according to the calculation uncertainty of the required opening degree, the detection uncertainty of the opening degree signal, and the adjustment uncertainty of the actuator.

[0128] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the second detection item based on the process quantity signals when the computer program is executed by the processor includes: obtaining the water level change rate within a preset time period according to the water level signal; the preset time period is determined according to the water level adjustment period of the evaporator; when the absolute value of the water level change rate is not less than a second preset value, determine that the fault detection value of the main feed water valve under the second detection item is a preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches a preset value.

[0129] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the third detection item based on the process quantity signals when the computer program is executed by the processor includes: obtaining the actual feed water flow rate corresponding to the flow rate signal, and obtaining the required feed water flow rate corresponding to the secondary circuit load; when the absolute value of the flow rate deviation between the actual feed water flow rate and the required feed water flow rate is not less than a third preset value, determine that the fault detection value of the main feed water valve under the third detection item is a preset value; the third preset value is determined according to the detection uncertainty of the flow rate signal, the calculation uncertainty of the required feed water flow rate, and a preset feed water flow rate deviation amount.

[0130] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the fourth detection item for the process quantity signal involved when the computer program is executed by the processor includes: obtaining the first change rate corresponding to the opening signal and the second change rate corresponding to the water level signal within the water level adjustment period of the evaporator; when the absolute value of the difference between the first change rate and the second change rate is greater than the sum of the absolute values, determining that the fault detection value of the main feed water valve under the fourth detection item is a preset value.

[0131] In one embodiment, the nuclear power unit further includes a main feed water pump; when the computer program is executed by the processor, the following steps are further implemented: when it is determined that the main feed water valve fails, obtaining the set speed of the main feed water pump, and controlling the operation of the main feed water pump according to the set speed to adjust the main feed water flow rate of the evaporator so that the water level of the evaporator is within a preset adjustment range.

[0132] In one embodiment, a computer program product is provided, including a computer program, which when executed by the processor implements the following steps: when the nuclear power unit is in a startup state, obtaining the process quantity signals of the nuclear power unit; the process quantity signals include the opening signal and the flow rate signal of the main feed water valve, and the water level signal of the evaporator; based on the process quantity signals, obtaining the fault detection value of the main feed water valve under the preset detection items; the preset detection items include the first detection item corresponding to the opening signal, the second detection item corresponding to the water level signal, the third detection item corresponding to the flow rate signal, and the fourth detection item corresponding to the opening signal and the water level signal; when the fault detection values corresponding to all the preset detection items are preset values, determining that the main feed water valve fails.

[0133] In one embodiment, the nuclear power unit further includes an actuator; the process of obtaining the fault detection value of the main feed water valve under the first detection item for the process quantity signal involved when the computer program is executed by the processor includes: obtaining the actual opening corresponding to the opening signal of the main feed water valve; obtaining the secondary circuit load of the nuclear power unit and determining the required opening corresponding to the secondary circuit load; when the absolute value of the valve position deviation between the actual opening and the required opening is not less than the first preset value, determining that the fault detection value of the main feed water valve under the first detection item is a preset value; the first preset value is determined according to the calculation uncertainty of the required opening, the detection uncertainty of the opening signal, and the adjustment uncertainty of the actuator.

[0134] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the second detection item based on the process quantity signal when the computer program is executed by the processor includes: obtaining the water level change rate within a preset time period according to the water level signal; the preset time period is determined according to the water level regulation period of the evaporator; when the absolute value of the water level change rate is not less than the second preset value, determining that the fault detection value of the main feed water valve under the second detection item is the preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches the preset value.

[0135] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the third detection item based on the process quantity signal when the computer program is executed by the processor includes: obtaining the actual feed water flow corresponding to the flow signal and the required feed water flow corresponding to the secondary circuit load; when the absolute value of the flow deviation between the actual feed water flow and the required feed water flow is not less than the third preset value, determining that the fault detection value of the main feed water valve under the third detection item is the preset value; the third preset value is determined according to the detection uncertainty of the flow signal, the calculation uncertainty of the required feed water flow, and the preset feed water flow deviation.

[0136] In one embodiment, the process of obtaining the fault detection value of the main feed water valve under the fourth detection item based on the process quantity signal when the computer program is executed by the processor includes: obtaining the first change rate corresponding to the opening signal and the second change rate corresponding to the water level signal within the water level regulation period of the evaporator; when the absolute value of the difference between the first change rate and the second change rate is greater than the absolute value, determining that the fault detection value of the main feed water valve under the fourth detection item is the preset value.

[0137] In one embodiment, the nuclear power unit further includes a main feed water pump; when the computer program is executed by the processor, the following steps are further implemented: when it is determined that the main feed water valve fails, obtaining the set speed of the main feed water pump, and controlling the operation of the main feed water pump according to the set speed to adjust the main feed water flow of the evaporator so that the water level of the evaporator is within the preset adjustment range.

[0138] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0139] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope recorded in the present application.

[0140] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for detecting the failure of a main feed water valve, characterized in that, Applied to a nuclear power unit; the nuclear power unit includes a main feed water valve and an evaporator; the method includes: When the nuclear power unit is in a startup state, obtaining the process quantity signals of the nuclear power unit; the process quantity signals include the opening degree signal and the flow rate signal of the main feed water valve, and the water level signal of the evaporator; Based on the process quantity signals, obtaining the fault detection value of the main feed water valve under a preset detection item; the preset detection items include a first detection item corresponding to the opening degree signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow rate signal, and a fourth detection item corresponding to the opening degree signal and the water level signal; When the fault detection values corresponding to all the preset detection items are preset values, determining that the main feed water valve is faulty.

2. The method according to claim 1, characterized in that, The nuclear power unit further includes an actuator; the process of obtaining the fault detection value of the main feed water valve under the first detection item based on the process quantity signals includes: Obtaining the actual opening degree corresponding to the opening degree signal of the main feed water valve; Obtaining the secondary circuit load of the nuclear power unit and determining the required opening degree corresponding to the secondary circuit load; When the absolute value of the valve position deviation between the actual opening degree and the required opening degree is not less than a first preset value, determining that the fault detection value of the main feed water valve under the first detection item is a preset value; the first preset value is determined according to the calculation uncertainty of the required opening degree, the detection uncertainty of the opening degree signal, and the adjustment uncertainty of the actuator.

3. The method according to claim 2, wherein The process of obtaining the fault detection value of the main feed water valve under the second detection item based on the process quantity signals includes: According to the water level signal, obtaining the water level change rate within a preset time period; the preset time period is determined according to the water level adjustment period of the evaporator; When the absolute value of the water level change rate is not less than a second preset value, determining that the fault detection value of the main feed water valve under the second detection item is a preset value; the second preset value is the water level change rate corresponding to when the absolute value of the valve position deviation reaches the preset value.

4. The method according to claim 2, wherein The process of obtaining the fault detection value of the main feed water valve under the third detection item based on the process quantity signals includes: Obtaining the actual feed water flow rate corresponding to the flow rate signal and obtaining the required feed water flow rate corresponding to the secondary circuit load; When the absolute value of the flow rate deviation between the actual feed water flow rate and the required feed water flow rate is not less than a third preset value, determining that the fault detection value of the main feed water valve under the third detection item is a preset value; the third preset value is determined according to the detection uncertainty of the flow rate signal, the calculation uncertainty of the required feed water flow rate, and a preset feed water flow rate deviation amount.

5. The method according to claim 3, wherein The process of obtaining the fault detection value of the main feed water valve under the fourth detection item based on the process quantity signals includes: Obtaining a first change rate corresponding to the opening degree signal and a second change rate corresponding to the water level signal within the water level adjustment period of the evaporator; When the absolute value of the difference between the first change rate and the second change rate is greater than the sum of the absolute values, determine that the fault detection value of the main feed water valve under the fourth detection item is a preset value.

6. The method according to claim 1, characterized in that, The nuclear power unit further includes a main feed water pump; the method further includes: When it is determined that the main feed water valve fails, obtain the set speed of the main feed water pump, and control the operation of the main feed water pump according to the set speed to adjust the main feed water flow rate of the evaporator so that the water level of the evaporator is within a preset adjustment range.

7. A main feed water valve fault detection device, characterized in that, Applied to a nuclear power unit; the nuclear power unit includes a main feed water valve and an evaporator; the device includes: A signal acquisition module, configured to acquire the process quantity signal of the nuclear power unit when the nuclear power unit is in a startup state; the process quantity signal includes the opening signal and the flow signal of the main feed water valve, and the water level signal of the evaporator; A fault detection module, configured to obtain the fault detection value of the main feed water valve under a preset detection item based on the process quantity signal; the preset detection item includes a first detection item corresponding to the opening signal, a second detection item corresponding to the water level signal, a third detection item corresponding to the flow signal, and a fourth detection item corresponding to the opening signal and the water level signal; A fault determination module, configured to determine that the main feed water valve fails when the fault detection values corresponding to all preset detection items are preset values.

8. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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