Evaporator water level control method and device, computer equipment, readable storage medium and program product

Abstract

The invention relates to an evaporator water level control method and device, computer equipment, a readable storage medium and a program product. The method comprises the steps that under the condition that a main feed water valve breaks down, a target evaporator which breaks down is obtained from a plurality of evaporators, the steam-water deviation value of the target evaporator is obtained according to a steam flow signal of the target evaporator, a target feed water pump is determined from a plurality of main feed water pumps according to the steam-water deviation value, and the set rotating speed of the target feed water pump is obtained; obtaining the rotating speed adjustment amount of the target feed pump according to the set rotating speed, obtaining the rotating speed adjustment rate according to the rotating speed adjustment amount, and controlling the target feed pump to operate according to the rotating speed adjustment rate so as to adjust the main feed water flow of the target evaporator and enable the water level of the target evaporator to be within a preset adjustment interval. The method can effectively guarantee the stable operation of the nuclear power unit.

Description

Technical Field

[0001] The present application relates to the field of evaporator control technology, and in particular to an evaporator water level control method, device, computer equipment, readable storage medium and program product. Background Art

[0002] The evaporator water level control system is one of the most critical and sensitive control systems in a nuclear power plant. Its stability is directly related to the safe and stable operation of nuclear power units. Precise control of the evaporator water level is crucial for maintaining the thermal balance of the steam generator, ensuring steam quality, and preventing reactor power fluctuations. Currently, abnormal evaporator water level control is one of the main causes of unit transients or automatic reactor shutdowns.

[0003] In traditional methods, redundancy has been achieved in the design of front-end sensors and intermediate controllers, significantly improving the reliability of the front-end and intermediate links. However, the actuators at the back end of the traditional water level control system (such as the main water supply valve) still use a non-redundant design, which may cause disturbances or transients in the control system due to actuator failure, affecting the normal operation of the nuclear power unit. Summary of the Invention

[0004] Based on this, it is necessary to provide an evaporator water level control method, device, computer equipment, readable storage medium and program product that can effectively ensure the stable operation of nuclear power units in response to the above technical problems.

[0005] In a first aspect, the present application provides an evaporator water level control method, comprising:

[0006] In the case of a main water supply valve failure, obtaining a target evaporator having a failure from a plurality of evaporators;

[0007] According to the steam flow signal of the target evaporator, a steam-water deviation value of the target evaporator is obtained, and according to the steam-water deviation value, a target feedwater pump is determined from multiple main feedwater pumps;

[0008] Obtaining a set speed of a target water supply pump, and obtaining a speed adjustment amount of the target water supply pump according to the set speed;

[0009] The speed adjustment rate is obtained according to the speed adjustment amount, and the operation of the target water supply pump is controlled according to the speed adjustment rate to adjust the main water supply flow of the target evaporator so that the water level of the target evaporator is within the preset adjustment range.

[0010] In one embodiment, the step of determining a target feedwater pump from a plurality of main feedwater pumps according to the steam-water deviation value includes:

[0011] When the steam-water deviation value is not greater than the preset threshold, the main feed water pump currently in operation is used as the target feed water pump;

[0012] When the steam-water deviation value is less than the preset threshold, all main feed water pumps are used as target feed water pumps; wherein the preset threshold is the increase in the main feed water flow of the target evaporator when the main feed water pump currently in operation increases from the current speed to the upper limit of the speed.

[0013] In one embodiment, the step of obtaining the speed adjustment rate according to the speed adjustment amount includes:

[0014] When the absolute value of the speed adjustment amount is less than the first preset value, the first rate is used as the speed adjustment rate;

[0015] When the absolute value of the speed adjustment amount is greater than the second preset value, the second rate is used as the speed adjustment rate;

[0016] When the absolute value of the rotational speed adjustment amount is not less than the first preset value and not greater than the second preset value, the rotational speed adjustment rate is determined according to the first rate and the second rate.

[0017] In one embodiment, the process of determining the first rate includes:

[0018] When the nuclear power unit is operating at full power, the change in the main feed water flow rate of the target evaporator during the process in which the deviation between the actual opening of the main feed water valve and the required opening reaches the preset value from 0;

[0019] A first rotation speed compensation amount and a first compensation duration corresponding to the change amount are obtained, and a first rate is obtained according to the first rotation speed compensation amount and the first compensation duration.

[0020] In one embodiment, the process of determining the second rate includes:

[0021] Obtaining a critical value of the main feed water flow rate of the target evaporator;

[0022] A second rotation speed compensation amount and a second compensation time duration corresponding to the critical value are obtained, and a second rate is obtained according to the second rotation speed compensation amount and the second compensation time duration.

[0023] In one embodiment, the method further comprises:

[0024] Get the upper limit rate of the target water supply pump;

[0025] When the second rate is greater than the upper limit rate, the upper limit rate is used as the rotation speed adjustment rate.

[0026] In a second aspect, the present application further provides an evaporator water level control device, comprising:

[0027] a target acquisition module, configured to acquire a target evaporator having a fault from a plurality of evaporators when a main water supply valve has a fault;

[0028] a deviation acquisition module, configured to acquire a steam-water deviation value of a target evaporator according to a steam flow signal of the target evaporator, and determine a target feedwater pump from a plurality of main feedwater pumps according to the steam-water deviation value;

[0029] The speed acquisition module is used to obtain the set speed of the target water supply pump and obtain the speed adjustment amount of the target water supply pump according to the set speed;

[0030] The water level regulation module is used to obtain the speed adjustment rate according to the speed adjustment amount, and control the operation of the target water supply pump according to the speed adjustment rate to adjust the main water supply flow of the target evaporator so that the water level of the target evaporator is within the preset adjustment range.

[0031] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements any one of the method steps in the first aspect when executing the computer program.

[0032] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which implements any one of the method steps in the first aspect when the computer program is executed by a processor.

[0033] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which implements any one of the method steps in the first aspect when executed by a processor.

[0034] The above-mentioned evaporator water level control method, device, computer equipment, readable storage medium and program product obtain the set speed of the target feed water pump, obtain the speed adjustment amount of the target feed water pump according to the set speed, obtain the speed adjustment rate according to the speed adjustment amount, and control the operation of the target feed water pump according to the speed adjustment rate to adjust the main feed water flow of the target evaporator so that the water level of the target evaporator is within the preset adjustment range. Through the speed setting of the main feed water pump, the water level of the faulty evaporator is effectively regulated to avoid disturbances to other normally operating evaporators, thereby avoiding triggering the evaporator water level reactor protection and causing the reactor to automatically shut down, thereby ensuring the stable operation of the nuclear power unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 1. is a logic diagram of evaporator water level control in one embodiment;

[0037] Figure 2 Flowchart of evaporator water level control in main water supply valve failure mode in one embodiment;

[0038] Figure 3 Schematic diagram of a flow chart of a method for controlling the water level of an evaporator in one embodiment;

[0039] Figure 4 A schematic diagram of a functional relationship for setting a given speed rate in one embodiment;

[0040] Figure 5 is a schematic diagram of an evaporator water level response curve in one embodiment;

[0041] Figure 6 A schematic flow chart of a method for controlling the water level of an evaporator in another embodiment;

[0042] Figure 7 is a structural block diagram of an evaporator water level control device in one embodiment;

[0043] Figure 8 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0045] In a nuclear power plant, the evaporator (also known as the steam generator) is the key link between the nuclear reactor and the steam turbine generator. The two are closely interdependent, jointly driving the efficient conversion of nuclear energy into electrical energy. The evaporator's operating principle is based on the reactor coolant flowing through the heat transfer tubes, transferring heat to the secondary water outside the tubes. This promotes the natural circulation of the secondary water within the steam generator, which in turn converts some of the water flowing outside the heat transfer tubes into saturated steam, which is then supplied to the main steam turbine and various auxiliary facilities, ensuring the stable operation of the entire system.

[0046] However, maintaining a stable water level on the secondary side of a steam generator during actual operation is a challenging task. Fluctuations in the secondary water level can cause a number of serious problems. On the one hand, excessively high water levels can worsen steam-water separation and exacerbate water carryover. This not only reduces steam quality and affects the efficiency of the main steam turbine, but can also cause erosion and damage to turbine blades over time, significantly shortening turbine service life and increasing equipment maintenance costs and the risk of downtime for overhauls. On the other hand, excessively low water levels can expose portions of the heat transfer tubes, causing localized overheating and seriously compromising their structural integrity. This can even lead to leakage accidents, threatening the safe operation of the entire unit. Insufficient steam production can also affect the system's normal power supply or energy supply.

[0047] When maintaining a stable water level on the secondary side of the steam generator, traditional methods mainly focus on evaporator water level control, which covers two key aspects: main feed water pump speed control and main feed water valve opening control.

[0048] Specifically, in the main feedwater pump speed control link, its core purpose is to ensure that the pressure drop of the regulating valve can always be maintained at a constant state and accurately adjust the feedwater flow. At the same time, in order to adapt to the dynamic changes in 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 pattern as the load changes. In this process, the main feedwater pump, as the actuator, shoulders the important task of precise regulation. The quality of its operating performance is directly related to the accuracy and timeliness of feedwater regulation. However, the existing main feedwater pump speed control strategy still has limitations when dealing with complex operating conditions and meeting the needs of high-precision water level control, making it difficult to achieve ideal dynamic matching of the steam-water pressure difference.

[0049] As for main feedwater valve opening control, since each steam generator is equipped with its own independent water level regulation system, the current method is to manually or automatically change the main feedwater valve opening to change the feedwater flow rate and thus control the evaporator water level. In this process, the main feedwater valve (main valve) and bypass feedwater valve (bypass valve) function as actuators. However, traditional main feedwater valve opening control methods have a slow adjustment response speed when faced with complex operating conditions such as rapid load changes and fluctuating water quality, and are prone to overshoot or undershoot. As a result, the water level control accuracy cannot meet the increasingly stringent industrial production requirements, and the coordination between different valves also lacks an efficient optimization mechanism.

[0050] In summary, when faced with complex and changeable operating conditions, traditional steam generator water level regulation technology has many shortcomings, whether it is the main feed water pump speed control or the main feed water valve opening control. It is difficult to ensure that the secondary side water level of the steam generator is always stable at the required set value, which to a large extent restricts the efficient and safe development of related industries.

[0051] Based on this, an embodiment of the present application provides an evaporator water level control method, which effectively adjusts the water level of the faulty evaporator by setting the speed of the main water supply pump, avoiding disturbances to other normally operating evaporators, thereby avoiding triggering the evaporator water level reactor protection and causing the reactor to automatically shut down, thereby ensuring the stable operation of the nuclear power unit.

[0052] In an exemplary embodiment, Figure 1 As shown in the figure, 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 mainly consists of the evaporator, main feed water pump, main feed water valve and corresponding pipeline components, such as Figure 1 As shown, is the pressure difference between steam and water, is the steam flow rate, is the steam pressure, is the water flow rate, Evaporator water level, Set the evaporator water level. For the second circuit impression load wide range, is the feed water temperature, For the second circuit impression load narrow range, Main water supply valve opening signal, Bypass valve opening signal, is the speed of the water feed pump.

[0053] Optionally, the main feedwater valve opening control is mainly used to set up an independent water level regulation system for each steam generator, and to control the evaporator water level by changing the opening of the main feedwater valve to change the feedwater flow rate. The main feed water pump speed control is mainly used to adjust 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 (i.e., the steam-water pressure differential) causes it to change parabolically with load changes. The actuator is the main feedwater pump. Under normal circumstances, the feedwater pump speed is automatically controlled. However, if the feedwater pump speed remains in automatic control during a main feedwater valve failure, the evaporator's water level will continue to rise or fall, triggering the evaporator water level reactor protection. Therefore, when the main feedwater valve fails, coordination and control of the feedwater pump speed is necessary to adjust the evaporator water level to near the evaporator water level setpoint, preventing the evaporator water level reactor protection from being directly triggered or extending the triggering time (buying time to address the main feedwater valve failure).

[0054] For example, Figure 2As shown, in the main feedwater valve failure mode, it is assumed that only one evaporator fails at the same time, because the probability of two evaporators failing at the same time is extremely low and can be ignored. The main purpose of evaporator water level control in the main feedwater valve failure mode is to stabilize the water level of the faulty evaporator, and at the same time control the water levels of the other two normal evaporators within a reasonable range. Therefore, on the basis of stabilizing the water level of the evaporator with the main feedwater valve failure, avoid causing large disturbances to the other two normal evaporators, and ensure that the evaporator water level reactor protection is not triggered during the adjustment process of the three evaporators. The main purpose of the main feedwater pump speed control is to adjust the pressure difference between the feedwater main pipe and the steam main pipe while maintaining the constant pressure drop of the regulating valve. Therefore, changing the speed of the main water supply pump will affect the water level control of the three evaporators. If only one evaporator fails at the same time, the water level of the evaporator with the main water supply valve failure is controlled by setting the water supply pump speed, while the water levels of the other two evaporators are automatically adjusted by adjusting the opening of the main water supply valve. To achieve closed-loop regulation of the evaporator water level.

[0055] In an exemplary embodiment, Figure 3 As shown, a method for controlling the water level of an evaporator is provided, comprising the following steps 302 to 308. In which:

[0056] S302: When a main water supply valve fails, a target evaporator with a failure is obtained from a plurality of evaporators.

[0057] Optionally, during the operation of a nuclear power unit, when there is a main feedwater valve failure, the target evaporator with the failure can be accurately located by checking multiple evaporators.

[0058] S304: Obtaining a steam-water deviation value of the target evaporator according to the steam flow signal of the target evaporator, and determining a target feed water pump from a plurality of main feed water pumps according to the steam-water deviation value.

[0059] Optionally, after the target evaporator is determined, the steam-to-water deviation value is calculated based on its steam flow rate signal. The steam flow rate signal reflects the real-time status of steam production and transmission within the evaporator. Since steam is generated by heating and vaporizing feedwater, the steam flow rate and feedwater flow rate theoretically have a stable correspondence. However, the deviation in actual operation contains critical information. By comparing the relationship between steam flow rate and expected feedwater flow rate, the steam-to-water deviation value is calculated. The steam-to-water deviation value represents the degree of imbalance in the steam-to-water conversion process within the evaporator. Based on this steam-to-water deviation value, the number of main feedwater pumps that need to be operated is determined, that is, the target feedwater pump is determined.

[0060] S306: Obtain the set speed of the target water supply pump, and obtain the speed adjustment amount of the target water supply pump according to the set speed.

[0061] Optionally, after determining the target feedwater pump, its set speed is obtained. This set speed is calculated based on the function calculations corresponding to the secondary circuit load and the feedwater pump speed, the steam-water deviation speed correction function, and the water level deviation speed correction function. Combined with the current real-time dynamics of the evaporator water level and the rate of change of the steam-water deviation, the target feedwater pump speed adjustment is determined. The speed adjustment specifies the required change in feedwater pump speed to return the evaporator water level to the normal range and is a key intermediate quantity for achieving precise regulation.

[0062] S308: Obtaining a speed adjustment rate according to the speed adjustment amount, and controlling the operation of the target water supply pump according to the speed adjustment rate to adjust the main water supply flow of the target evaporator so that the water level of the target evaporator is within a preset adjustment range.

[0063] Optionally, the calculated speed adjustment value is further derived to determine the speed adjustment rate. This speed adjustment rate takes into account physical characteristics such as the evaporator system's inertia, heat transfer delay, and pipe flow response time. This ensures that the feedwater pump speed adjustment process is neither too abrupt, causing system shocks like water hammer and damaging equipment, nor too slow, resulting in prolonged water level uncontrollable conditions. Based on the determined speed adjustment rate, the control system precisely controls the operation of the target feedwater pump, changing its speed in real time, thereby finely adjusting the main feedwater flow to the target evaporator.

[0064] In the above-mentioned evaporator water level control method, the set speed of the target feed water pump is obtained, the speed adjustment amount of the target feed water pump is obtained according to the set speed, the speed adjustment rate is obtained according to the speed adjustment amount, and the operation of the target feed water pump is controlled according to the speed adjustment rate to adjust the main feed water flow of the target evaporator so that the water level of the target evaporator is within the preset adjustment range. Through the speed setting of the main feed water pump, the water level of the faulty evaporator is effectively regulated to avoid disturbance to other normally operating evaporators, thereby avoiding triggering the evaporator water level reactor protection and causing the reactor to automatically shut down, thereby ensuring the stable operation of the nuclear power unit.

[0065] In an exemplary embodiment, the step of determining a target feed water pump from a plurality of main feed water pumps based on a steam-water deviation value includes: when the steam-water deviation value is not greater than a preset threshold value, using the main feed water pump currently in operation as the target feed water pump; when the steam-water deviation value is less than a preset threshold value, using all main feed water pumps as target feed water pumps; wherein the preset threshold value is the increase in the main feed water flow rate of the target evaporator when the main feed water pump currently in operation increases from a current speed to an upper limit of the speed.

[0066] Optionally, the steam-water deviation value reflects an indicator of the flow balance state during the steam-water conversion process in the target evaporator, and the preset threshold value is set according to the increase in the main feed water flow of the target evaporator when the main feed water pump in operation increases from the current speed to the upper speed limit under the current operating conditions. If the steam-water deviation value is not greater than the preset threshold value, it means that the current steam-water deviation is relatively small, and it is possible to restore the evaporator water level to a normal range by adjusting the existing main feed water pump in operation. When the steam-water deviation value is less than the preset threshold value, it means that the current steam-water deviation is large, and it may not be possible to effectively adjust the evaporator water level to a normal range by relying solely on the existing operating main feed water pump. In this case, all main feed water pumps need to be used as target feed water pumps, and the adjustment capabilities of all main feed water pumps need to be fully utilized to increase the main feed water flow rate, so as to more effectively adjust the water level of the target evaporator and return it to the preset adjustment range as soon as possible.

[0067] For example, combined Figure 2 It can be seen that there are 3 main feed water pumps in total, 2 of which are in operation under normal operating conditions. When the steam-water deviation of the faulty evaporator meets When the steam-water deviation of the faulty evaporator meets When the two main feed water pumps operating normally cannot meet the main feed water flow demand, it is necessary to start the third main feed water pump and adjust the evaporator water level by setting the speed of the main feed water pump. To add the main water pump start threshold, It is the increase in main feed water flow when the speed of two main feed water pumps in normal operation is increased to the upper limit value, while taking into account the margin range of a certain process system.

[0068] In this embodiment, by comparing the steam-water deviation value with the preset threshold to determine the target water supply pump, the appropriate number of main water supply pumps can be accurately selected for adjustment according to different steam-water deviation conditions, ensuring that the evaporator water level can be quickly and effectively restored to the normal range, thereby improving the accuracy and effectiveness of water level control.

[0069] In an exemplary embodiment, the step of obtaining the speed adjustment rate based on the speed adjustment amount includes: when the absolute value of the speed adjustment amount is less than a first preset value, using the first rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is greater than a second preset value, using the second rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is not less than the first preset value and not greater than the second preset value, determining the speed adjustment rate based on the first rate and the second rate.

[0070] Alternatively, when the absolute value of the speed adjustment is small, indicating that the target feedwater pump speed requires minimal adjustment, the first rate is used as the speed adjustment rate. The first rate is typically a relatively small value, which allows for smoother and more precise speed adjustment, avoiding drastic changes in the feedwater pump speed due to an excessively large adjustment rate, thereby preventing significant fluctuations in the evaporator water level. If the absolute value of the speed adjustment is large, indicating that the evaporator water level deviates significantly from the preset value, a significant adjustment of the feedwater pump speed is required to quickly return the water level to within the preset adjustment range. The second rate is typically a large value, which allows for rapid changes in the feedwater pump speed, thereby rapidly changing the main feedwater flow rate and accelerating the evaporator water level adjustment to accommodate larger water level deviations. When the absolute value of the speed adjustment is in the middle range, the speed adjustment rate is determined based on the first and second rates. A linear or nonlinear interpolation method is typically used to calculate a moderate adjustment rate, ensuring that the feedwater pump speed adjustment maintains a certain adjustment speed while avoiding excessive impact on the evaporator water level.

[0071] For example, Figure 4 As shown in the figure, a speed setting function relationship is established. The main purpose of setting it is to prevent the main water supply pump speed from being set to ,in, is the pump speed obtained based on the secondary circuit load, is the speed correction value obtained based on the steam-water deviation, The speed correction value is obtained based on the water level deviation. Due to the delay in judging the main water supply valve failure, if the speed of the original water supply pump is The deviation is too large, the main water flow Exceeding the critical point of the closed-loop regulation deviation of the main feed water flow will cause a relatively large disturbance to the evaporator water level, and also affect the other two normal evaporator water level control. In order to prevent the main feed water pump speed from being set to , which will instantly cause excessive disturbance to the evaporator water level. To avoid possible triggering of the evaporator water level reactor automatic protection, increase the speed setting to keep it within the controllable adjustment range of the normal evaporator water level.

[0072] For example, when the main feed water pump speed meets When the speed is set to ; When the main feed water pump speed meets When the speed is set to ; When the main feed water pump speed meets When the speed is set at ~ Linear change. and The value of can be obtained through the evaporator water level disturbance test.

[0073] In this embodiment, by setting different speed adjustment rates according to different speed adjustment ranges, accurate water level control can be achieved under different water level deviation conditions, avoiding over- or under-adjustment and improving the accuracy of water level control.

[0074] In an exemplary embodiment, the process of determining the first rate includes: when the nuclear power unit is operating at full power, in the process of the deviation between the actual opening of the main feed water valve and the required opening reaching a preset value from 0, the change in the main feed water flow of the target evaporator; obtaining a first speed compensation amount and a first compensation time corresponding to the change, and obtaining the first rate based on the first speed compensation amount and the first compensation time.

[0075] Optionally, when the nuclear power unit is operating at full power, as the deviation between the actual opening of the main feedwater valve and the required opening reaches a preset value from 0, the change in the main feedwater flow rate of the target evaporator is obtained. Based on the change in the main feedwater flow rate, a corresponding first speed compensation amount and first compensation duration are obtained. The first speed compensation amount refers to the speed adjustment required for the target feedwater pump to adapt to the change in the main feedwater flow rate, and the first compensation duration refers to the time allowed to complete this speed adjustment. A first rate is calculated based on the first speed compensation amount and the first compensation duration. The first rate is actually the adjustment amount of the feedwater pump speed per unit time. Through this calculation, a feedwater pump speed adjustment rate corresponding to a specific main feedwater valve opening deviation and main feedwater flow rate change under the full power operation of the nuclear power unit is obtained.

[0076] For example, the first rate The setting mainly meets the rapidity of the water supply pump speed and the flow change when the actual opening of the main water supply valve deviates from the required opening by 3% (experience value) under full power operation conditions. The speed of the water pump increases during the time , can make up for the change in main water supply flow caused by the change in the opening of the main water supply valve. At this time, the value is determined , and determine ,in, The experience value is 30s.

[0077] In this embodiment, by determining the first rate under the full-power operating conditions of the nuclear power unit, the rate can be accurately adapted to the operating characteristics of the nuclear power unit under such typical operating conditions, and the main feed water flow can be more accurately controlled, so that the evaporator water level can be more accurately close to the preset value.

[0078] In an exemplary embodiment, the process of determining the second rate includes: obtaining a critical value of the main water feed flow of the target evaporator; obtaining a second speed compensation amount and a second compensation time corresponding to the critical value, and obtaining the second rate based on the second speed compensation amount and the second compensation time.

[0079] Optionally, the critical value represents a specific limit for the target evaporator's main feedwater flow rate. This value is typically determined based on a combination of factors, including the evaporator's design parameters, operational safety requirements, and the overall operational characteristics of the nuclear power unit. It indicates that the main feedwater flow rate has reached a state requiring a special control strategy. The second speed compensation refers to the speed adjustment required for the target feedwater pump to effectively control the water level in the target evaporator when the main feedwater flow rate reaches the critical value. The second compensation duration is the time allowed to complete this speed adjustment. The second rate is calculated based on the second speed compensation and the second compensation duration, where the second rate represents the adjustment in feedwater pump speed per unit time when the main feedwater flow rate reaches the critical value.

[0080] For example, the second rate The setting can not only ensure that the water supply pump can reach the expected set value as quickly as possible, but also meet the control of water level disturbance. According to the simulator verification curve method, when the feed water pump speed is changed instantly , which in turn causes the change in main feed water flow to become the critical point of the closed-loop regulation deviation of the main feed water flow , then confirm value, and determine ,in, The empirical value is 1min.

[0081] In this embodiment, by determining the second rate corresponding to the critical value of the target evaporator main water supply flow rate, an appropriate control strategy can be adopted when the main water supply flow rate reaches a critical state to avoid excessive fluctuation or loss of control of the evaporator water level and ensure the stability of the evaporator water level.

[0082] In an exemplary embodiment, the method further includes: acquiring an upper limit rate of the target water supply pump; and using the upper limit rate as the speed adjustment rate when the second rate is greater than the upper limit rate.

[0083] Optionally, the upper limit rate of the target water supply pump represents the maximum speed change rate that the target water supply pump can achieve within a safe operating range. To avoid problems such as water supply pump motor overload and mechanical component damage caused by adjusting the water supply pump speed at the second rate, when the second rate is greater than the upper limit rate, the upper limit rate is used as the speed adjustment rate to ensure that the speed adjustment of the water supply pump is within a safe and controllable range.

[0084] For example, the second rate Less than or equal to the maximum rate limit of the feedwater pump, if If the upper limit rate is greater than the maximum rate limit of the water feed pump, the upper limit rate will be used as The numerical value of .

[0085] In this embodiment, by limiting the speed adjustment rate to within the upper limit rate, the target feedwater pump is prevented from exceeding its safe operating range due to excessive speed adjustment, thereby ensuring the stable operation of the evaporator and improving the stability of the nuclear power unit.

[0086] In an exemplary embodiment, Figure 5 As shown, a method for controlling the water level of an evaporator is provided, the method comprising the following steps:

[0087] In the case of a main feedwater valve failure, a target evaporator having the failure is obtained from among the plurality of evaporators.

[0088] According to the steam flow signal of the target evaporator, the steam-water deviation value of the target evaporator is obtained. When the steam-water deviation value is not greater than the preset threshold value, the main feed water pump currently in operation is used as the target feed water pump; when the steam-water deviation value is less than the preset threshold value, all main feed water pumps are used as target feed water pumps; wherein the preset threshold value is the increase in the main feed water flow of the target evaporator when the main feed water pump currently in operation increases from the current speed to the upper limit of the speed.

[0089] The set speed of the target water supply pump is obtained, and the speed adjustment amount of the target water supply pump is obtained according to the set speed.

[0090] When the nuclear power unit is operating at full power, the change in the main feed water flow rate of the target evaporator occurs during the process in which the deviation between the actual opening and the required opening of the main feed water valve reaches a preset value from 0; the first speed compensation amount and the first compensation duration corresponding to the change are obtained, and the first rate is obtained based on the first speed compensation amount and the first compensation duration.

[0091] Obtain a critical value of the main feed water flow of the target evaporator; obtain a second speed compensation amount and a second compensation time corresponding to the critical value, and obtain a second rate according to the second speed compensation amount and the second compensation time.

[0092] When the absolute value of the speed adjustment amount is less than the first preset value, the first rate is used as the speed adjustment rate; when the absolute value of the speed adjustment amount is greater than the second preset value, the second rate is used as the speed adjustment rate; when the absolute value of the speed adjustment amount is not less than the first preset value and not greater than the second preset value, the speed adjustment rate is determined based on the first rate and the second rate.

[0093] The target feed water pump is controlled to operate according to the speed adjustment rate to adjust the main feed water flow of the target evaporator so that the water level of the target evaporator is within the preset adjustment range.

[0094] The upper limit rate of the target water supply pump is obtained; when the second rate is greater than the upper limit rate, the upper limit rate is used as the speed adjustment rate.

[0095] For example, using the above evaporator water level control method, when the main water supply valve fails, the evaporator water level is adjusted to the stable range by setting the water supply pump speed. The response curves of the various variables are as follows: Figure 6 As shown by Figure 6 It can be seen that the evaporator water level control method can effectively avoid the abnormal evaporator water level triggering the reactor automatic shutdown protection, ensuring the safe and stable operation of the nuclear power unit.

[0096] In this embodiment, the set speed of the target feed water pump is obtained, the speed adjustment amount of the target feed water pump is obtained according to the set speed, the speed adjustment rate is obtained according to the speed adjustment amount, and the operation of the target feed water pump is controlled according to the speed adjustment rate to adjust the main feed water flow of the target evaporator so that the water level of the target evaporator is within the preset adjustment range. Through the speed setting of the main feed water pump, the water level of the faulty evaporator is effectively regulated to avoid disturbance to other normally operating evaporators, thereby avoiding triggering the evaporator water level reactor protection and causing the reactor to automatically shut down, thereby ensuring the stable operation of the nuclear power unit.

[0097] It should be understood that, although the steps in the flowcharts of the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts of the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0098] Based on the same inventive concept, embodiments of the present application also provide an evaporator water level control device for implementing the aforementioned evaporator water level control method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the evaporator water level control device provided below can be found in the above-described limitations of the evaporator water level control method and will not be further elaborated here.

[0099] In an exemplary embodiment, Figure 7 As shown, an evaporator water level control device is provided, comprising: a target acquisition module 10, a deviation acquisition module 20, a speed acquisition module 30 and a water level adjustment module 40, wherein:

[0100] The target acquisition module 10 is configured to acquire a target evaporator having a fault from a plurality of evaporators when a main water supply valve has a fault.

[0101] The deviation acquisition module 20 is used to obtain the steam-water deviation value of the target evaporator according to the steam flow signal of the target evaporator, and determine the target feed water pump from multiple main feed water pumps according to the steam-water deviation value.

[0102] The speed acquisition module 30 is used to acquire the set speed of the target water supply pump and acquire the speed adjustment amount of the target water supply pump according to the set speed.

[0103] The water level regulating module 40 is used to obtain the speed adjustment rate according to the speed adjustment amount, and control the operation of the target water supply pump according to the speed adjustment rate to adjust the main water supply flow of the target evaporator so that the water level of the target evaporator is within the preset adjustment range.

[0104] In an exemplary embodiment, the deviation acquisition module 20 is also used to use the main feed water pump that is currently in operation as the target feed water pump when the steam-water deviation value is not greater than a preset threshold value; and to use all main feed water pumps as target feed water pumps when the steam-water deviation value is less than the preset threshold value; wherein the preset threshold value is the increase in the main feed water flow rate of the target evaporator when the main feed water pump that is currently in operation increases from the current speed to the upper limit of the speed.

[0105] In an exemplary embodiment, the speed acquisition module 30 is further configured to use the first rate as the speed adjustment rate when the absolute value of the speed adjustment amount is less than a first preset value; use the second rate as the speed adjustment rate when the absolute value of the speed adjustment amount is greater than a second preset value; and determine the speed adjustment rate based on the first rate and the second rate when the absolute value of the speed adjustment amount is not less than the first preset value and not greater than the second preset value.

[0106] In an exemplary embodiment, the speed acquisition module 30 is also used to obtain the change in the main feed water flow of the target evaporator when the deviation between the actual opening and the required opening of the main feed water valve reaches a preset value from 0 when the nuclear power unit is operating at full power; obtain a first speed compensation amount and a first compensation time corresponding to the change, and obtain a first rate based on the first speed compensation amount and the first compensation time.

[0107] In an exemplary embodiment, the speed acquisition module 30 is also used to obtain a critical value of the main water feed flow of the target evaporator; obtain a second speed compensation amount and a second compensation time corresponding to the critical value, and obtain a second rate based on the second speed compensation amount and the second compensation time.

[0108] In an exemplary embodiment, the speed acquisition module 30 is further configured to acquire an upper limit speed of the target water supply pump; when the second speed is greater than the upper limit speed, the upper limit speed is used as the speed adjustment rate.

[0109] Each module in the evaporator water level control device can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0110] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 8 As shown. The computer device includes a processor, memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are connected to the system bus via the input / output interface. 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 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 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 via wired or wireless communication, and the wireless communication can be achieved via Wi-Fi, a mobile cellular network, near-field communication (NFC), or other technologies. When executed by the processor, the computer program implements an evaporator water level control method. The display unit of the computer device is used to produce a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse.

[0111] Those skilled in the art will understand that Figure 8The structure shown in the figure is only a block diagram of a part of the structure 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 shown in the figure, or combine certain components, or have a different component arrangement.

[0112] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the following steps when executing the computer program: in the event of a main feed water valve failure, obtaining a target evaporator with a failure from multiple evaporators; obtaining a steam-water deviation value of the target evaporator based on a steam flow signal of the target evaporator, and determining a target feed water pump from multiple main feed water pumps based on the steam-water deviation value; obtaining a set speed of the target feed water pump, and obtaining a speed adjustment amount of the target feed water pump based on the set speed; obtaining a speed adjustment rate based on the speed adjustment amount, and controlling the operation of the target feed water pump according to the speed adjustment rate to adjust the main feed water flow of the target evaporator so that the water level of the target evaporator is within a preset adjustment range.

[0113] In one embodiment, when a processor executes a computer program, the process involves determining a target feed water pump from a plurality of main feed water pumps based on a steam-water deviation value, including: when the steam-water deviation value is not greater than a preset threshold value, using the main feed water pump that is currently in operation as the target feed water pump; when the steam-water deviation value is less than a preset threshold value, using all main feed water pumps as target feed water pumps; wherein the preset threshold value is the increase in the main feed water flow rate of the target evaporator when the main feed water pump that is currently in operation increases from a current speed to an upper limit of the speed.

[0114] In one embodiment, the process of obtaining a speed adjustment rate based on a speed adjustment amount when a processor executes a computer program includes: when the absolute value of the speed adjustment amount is less than a first preset value, using a first rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is greater than a second preset value, using a second rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is not less than the first preset value and not greater than the second preset value, determining the speed adjustment rate based on the first rate and the second rate.

[0115] In one embodiment, the process of determining the first rate involved when the processor executes the computer program includes: when the nuclear power unit is operating at full power, in the process of the deviation between the actual opening of the main feed water valve and the required opening reaching a preset value from 0, the change in the main feed water flow of the target evaporator; obtaining a first speed compensation amount and a first compensation time corresponding to the change, and obtaining the first rate based on the first speed compensation amount and the first compensation time.

[0116] In one embodiment, the process of determining the second rate involved in the processor executing the computer program includes: obtaining a critical value of the main water feed flow of the target evaporator; obtaining a second speed compensation amount and a second compensation time corresponding to the critical value, and obtaining the second rate based on the second speed compensation amount and the second compensation time.

[0117] In one embodiment, when the processor executes the computer program, the processor further implements the following steps: obtaining an upper limit rate of the target water supply pump; and using the upper limit rate as the speed adjustment rate when the second rate is greater than the upper limit rate.

[0118] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented: in the event of a main feed water valve failure, obtaining a target evaporator with a failure from multiple evaporators; obtaining a steam-water deviation value of the target evaporator based on a steam flow signal of the target evaporator, and determining a target feed water pump from multiple main feed water pumps based on the steam-water deviation value; obtaining a set speed of the target feed water pump, and obtaining a speed adjustment amount of the target feed water pump based on the set speed; obtaining a speed adjustment rate based on the speed adjustment amount, and controlling the operation of the target feed water pump according to the speed adjustment rate to adjust the main feed water flow of the target evaporator so that the water level of the target evaporator is within a preset adjustment range.

[0119] In one embodiment, when a computer program is executed by a processor, it involves determining a target feed water pump from multiple main feed water pumps based on a steam-water deviation value, including: when the steam-water deviation value is not greater than a preset threshold value, using the main feed water pump that is currently in operation as the target feed water pump; when the steam-water deviation value is less than a preset threshold value, using all main feed water pumps as target feed water pumps; wherein the preset threshold value is the increase in the main feed water flow rate of the target evaporator when the main feed water pump that is currently in operation increases from the current speed to the upper limit of the speed.

[0120] In one embodiment, the computer program, when executed by a processor, involves obtaining a speed adjustment rate based on a speed adjustment amount, including: when the absolute value of the speed adjustment amount is less than a first preset value, using a first rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is greater than a second preset value, using a second rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is not less than the first preset value and not greater than the second preset value, determining the speed adjustment rate based on the first rate and the second rate.

[0121] In one embodiment, the process of determining the first rate involved when the computer program is executed by the processor includes: when the nuclear power unit is operating at full power, in the process of the deviation between the actual opening of the main feed water valve and the required opening reaching a preset value from 0, the change in the main feed water flow of the target evaporator; obtaining a first speed compensation amount and a first compensation time corresponding to the change, and obtaining the first rate based on the first speed compensation amount and the first compensation time.

[0122] In one embodiment, the process of determining the second rate involved when the computer program is executed by the processor includes: obtaining a critical value of the main water feed flow of the target evaporator; obtaining a second speed compensation amount and a second compensation time corresponding to the critical value, and obtaining the second rate based on the second speed compensation amount and the second compensation time.

[0123] In one embodiment, when the computer program is executed by the processor, the following steps are further implemented: obtaining an upper limit rate of the target water supply pump; and using the upper limit rate as the speed adjustment rate when the second rate is greater than the upper limit rate.

[0124] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps: in the presence of a main feed water valve failure, obtaining a target evaporator with the failure from a plurality of evaporators; obtaining a steam-water deviation value of the target evaporator based on a steam flow signal of the target evaporator, and determining a target feed water pump from a plurality of main feed water pumps based on the steam-water deviation value; obtaining a set speed of the target feed water pump, and obtaining a speed adjustment amount of the target feed water pump based on the set speed; obtaining a speed adjustment rate based on the speed adjustment amount, and controlling the operation of the target feed water pump according to the speed adjustment rate to adjust the main feed water flow of the target evaporator so that the water level of the target evaporator is within a preset adjustment range.

[0125] In one embodiment, when a computer program is executed by a processor, it involves determining a target feed water pump from multiple main feed water pumps based on a steam-water deviation value, including: when the steam-water deviation value is not greater than a preset threshold value, using the main feed water pump that is currently in operation as the target feed water pump; when the steam-water deviation value is less than a preset threshold value, using all main feed water pumps as target feed water pumps; wherein the preset threshold value is the increase in the main feed water flow rate of the target evaporator when the main feed water pump that is currently in operation increases from the current speed to the upper limit of the speed.

[0126] In one embodiment, the computer program, when executed by a processor, involves obtaining a speed adjustment rate based on a speed adjustment amount, including: when the absolute value of the speed adjustment amount is less than a first preset value, using a first rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is greater than a second preset value, using a second rate as the speed adjustment rate; when the absolute value of the speed adjustment amount is not less than the first preset value and not greater than the second preset value, determining the speed adjustment rate based on the first rate and the second rate.

[0127] In one embodiment, the process of determining the first rate involved when the computer program is executed by the processor includes: when the nuclear power unit is operating at full power, in the process of the deviation between the actual opening of the main feed water valve and the required opening reaching a preset value from 0, the change in the main feed water flow of the target evaporator; obtaining a first speed compensation amount and a first compensation time corresponding to the change, and obtaining the first rate based on the first speed compensation amount and the first compensation time.

[0128] In one embodiment, the process of determining the second rate involved when the computer program is executed by the processor includes: obtaining a critical value of the main water feed flow of the target evaporator; obtaining a second speed compensation amount and a second compensation time corresponding to the critical value, and obtaining the second rate based on the second speed compensation amount and the second compensation time.

[0129] In one embodiment, when the computer program is executed by the processor, the following steps are further implemented: obtaining an upper limit rate of the target water supply pump; and using the upper limit rate as the speed adjustment rate when the second rate is greater than the upper limit rate.

[0130] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the 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-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this 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), magnetic 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 take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0131] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, 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, they should be considered to be within the scope of this application.

[0132] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for controlling the water level of an evaporator, characterized in that: Applicable to a nuclear power unit; the nuclear power unit includes multiple main feed water valves, multiple evaporators and multiple main feed water pumps; the method includes: In the case of a main water supply valve failure, obtaining a target evaporator having a failure from a plurality of evaporators; obtaining a steam-water deviation value of the target evaporator according to a steam flow signal of the target evaporator, and determining a target feedwater pump from a plurality of main feedwater pumps according to the steam-water deviation value; Obtaining a set speed of the target water supply pump, and obtaining a speed adjustment amount of the target water supply pump according to the set speed; A speed adjustment rate is obtained according to the speed adjustment amount, and the target water supply pump is controlled to operate according to the speed adjustment rate to adjust the main water supply flow of the target evaporator so that the water level of the target evaporator is within a preset adjustment range.

2. The method according to claim 1, characterized in that Determining a target feed water pump from a plurality of main feed water pumps according to the steam-water deviation value includes: When the steam-water deviation value is not greater than a preset threshold, the main water supply pump currently in operation is used as the target water supply pump; When the steam-water deviation value is less than the preset threshold value, all main feed water pumps are used as target feed water pumps; wherein, the preset threshold value is the increase in the main feed water flow rate of the target evaporator when the main feed water pump currently in operation increases from the current speed to the upper limit of the speed.

3. The method according to claim 1, characterized in that The obtaining of the speed adjustment rate according to the speed adjustment amount includes: When the absolute value of the speed adjustment amount is less than a first preset value, the first rate is used as the speed adjustment rate; When the absolute value of the speed adjustment amount is greater than a second preset value, the second rate is used as the speed adjustment rate; When the absolute value of the rotational speed adjustment amount is not less than the first preset value and not greater than the second preset value, a rotational speed adjustment rate is determined according to the first rate and the second rate.

4. The method according to claim 3, characterized in that The process of determining the first rate includes: When the nuclear power unit is operating at full power, the change in the main feed water flow rate of the target evaporator during the process in which the deviation between the actual opening and the required opening of the main feed water valve reaches a preset value from 0; A first rotation speed compensation amount and a first compensation duration corresponding to the change amount are obtained, and a first rate is obtained according to the first rotation speed compensation amount and the first compensation duration.

5. The method according to claim 3, characterized in that The process of determining the second rate includes: Obtaining a critical value of the main feed water flow rate of the target evaporator; A second rotation speed compensation amount and a second compensation duration corresponding to the critical value are obtained, and a second rate is obtained according to the second rotation speed compensation amount and the second compensation duration.

6. The method according to claim 5, characterized in that The method further comprises: Obtaining an upper limit rate of the target water supply pump; When the second rate is greater than the upper limit rate, the upper limit rate is used as the rotation speed adjustment rate.

7. An evaporator water level control device, characterized in that: Applicable to a nuclear power unit; the nuclear power unit includes multiple main feed water valves, multiple evaporators and multiple main feed water pumps; the device includes: a target acquisition module, configured to acquire a target evaporator having a fault from a plurality of evaporators when a main water supply valve has a fault; a deviation acquisition module, configured to acquire a steam-water deviation value of the target evaporator according to the steam flow signal of the target evaporator, and determine a target feedwater pump from a plurality of main feedwater pumps according to the steam-water deviation value; A speed acquisition module, configured to acquire a set speed of the target water supply pump and acquire a speed adjustment amount of the target water supply pump according to the set speed; The water level regulating module is used to obtain a speed adjustment rate according to the speed adjustment amount, and control the operation of the target water supply pump according to the speed adjustment rate to adjust the main water supply flow of the target evaporator so that the water level of the target evaporator is within a preset adjustment range.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: 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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