Liquid level control method and device of nuclear power plant steam generator, electronic equipment and medium

Abstract

The invention provides a liquid level control method and device for a nuclear power station steam generator, electronic equipment and a medium, and relates to the technical field of nuclear power stations. When the power change rate of the reactor exceeds a change rate threshold value, adjusting the opening degree of a main feed water adjusting valve to a preset opening degree threshold value, adjusting the rotating speed of a main feed water pump to a preset rotating speed threshold value, continuously monitoring the current liquid level of the steam generator, and when the current liquid level is monitored to meet a preset liquid level condition, starting the steam generator; and the initial control mode is recovered to control the opening degree of the main feed water regulating valve and the rotating speed of the main feed water pump. By means of the mode, when a reactor fluctuates severely, the rotating speed of the main feed regulating valve and the rotating speed of the main feed pump are adjusted in place at a time according to the preset opening threshold value and the preset rotating speed threshold value, and the situation that the SG liquid level is out of control in the repeated adjusting process of the opening of the main feed regulating valve and the rotating speed of the main feed pump is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear power plants, and in particular to a liquid level control method for a nuclear power plant steam generator, a liquid level control device for a nuclear power plant steam generator, an electronic device, and a computer storage medium. Background Art

[0002] In a nuclear power plant, SG (Steam Generator) is a key device between the reactor coolant system and the steam turbine. It is used to transfer the heat of the reactor coolant (such as primary circuit water) to the secondary circuit working fluid (such as water), causing it to evaporate into high-temperature and high-pressure steam to drive the steam turbine generator set to generate electricity.

[0003] To ensure the safety and stability of steam turbine generator sets, nuclear power plants primarily utilize electric main feedwater pumps (MFFPs). These pumps are required to respond to the variable speed requirements of the feedwater flow control system to provide an appropriate feedwater flow to the SG within the full reactor load range. Typically, under high-load conditions, the opening of the MFFP control valve is controlled by parameters such as feedwater flow, steam flow, and SG level. Under low-load conditions, the SG level is the primary factor controlling the MFFP opening. Furthermore, the MFFP speed is controlled by the pressure differential between the steam header and the feedwater pump outlet header. This control strategy effectively maintains a stable SG level during stable operation and when the reactor experiences minor fluctuations. However, during significant fluctuations, the MFFP opening and feedwater pump speed cannot converge, leading to uncontrolled SG levels and unnecessary activation of safety systems, which in turn impacts the reactor's economic operability and reliability. Summary of the Invention

[0004] In view of this, the present application provides a liquid level control method, device, electronic equipment and medium for a nuclear power plant steam generator, which can adjust the main feed water regulating valve opening and the main feed water pump speed at one time when the reactor experiences severe fluctuations, thereby avoiding the SG liquid level from getting out of control during repeated adjustment of the main feed water regulating valve opening and the main feed water pump speed.

[0005] In a first aspect, the present application provides a liquid level control method for a nuclear power plant steam generator, the method being applied to a liquid level control system of a steam generator, the system comprising a steam generator, a main feedwater flow channel, a main feedwater pump, and a main feedwater regulating valve, the method comprising:

[0006] Get the power of the reactor;

[0007] If the power change rate of the reactor detected according to the power exceeds a change rate threshold, adjusting the opening of the main feed water regulating valve to a preset opening threshold, and adjusting the speed of the main feed water pump to a preset speed threshold;

[0008] continuously monitoring the current liquid level of the steam generator;

[0009] When it is monitored that the current liquid level meets the preset liquid level condition, the initial control mode is restored to control the opening of the main water supply regulating valve and the speed of the main water supply pump.

[0010] In one embodiment, after continuously monitoring the current liquid level of the steam generator, the method further comprises: issuing a reactor shutdown signal if it is detected that the current liquid level is less than a lower limit value.

[0011] In one embodiment, the method further comprises:

[0012] Obtain the first operating parameter of the steam generator and the water density ρ at the main feed water pump pump , the second operating parameter of the reactor cooling system and the core heat generation q of the reactor corresponding to the reactor cooling system c ; Wherein, the first operating parameter includes any one or more of the following: water quality M of the steam generator SG , steam generator temperature T SG and designated parameters at various locations of the steam generator; the second operating parameter includes any one or more of the following: reactor coolant system water quality M RCS , reactor coolant system temperature T RCS ;

[0013] According to the first operating parameter, ρ pump , the second operating parameter, q c and a preset function to determine a preset opening threshold and a preset speed threshold.

[0014] In one embodiment, the specified parameters include any one or more of the following: water density ρ i , circulation area A i , along-the-line loss coefficient f i , length l i , hydraulic diameter d i , and the local loss coefficient k i , the preset function includes the following formula:

[0015]

[0016] in, is the mass flow rate entering the steam generator, is the mass flow rate out of the steam generator, and is the steam generator pressure P SG function; g is the acceleration due to gravity, H pump The head of the main water supply pump, and H pump yes and the function of the main feed water pump speed; P SG is the steam generator pressure, and P SG is the steam generator temperature T sG Function; CV valve The flow resistance of the main water supply regulating valve, and CV valve is a function of valve opening; H RCS is the enthalpy of the reactor coolant system, and H RCS is the reactor coolant system temperature T RCS function; h is the heat transfer coefficient, A SG is the heat transfer area, and A SG is the steam generator water mass M SG function.

[0017] In a second aspect, the present application provides a steam generator liquid level control device, the device comprising a power operation logic unit, a high value trigger logic unit, a first liquid level trigger logic unit, an RS trigger logic unit, a first switch logic unit for controlling the opening of a main feed water regulating valve, and a second switch logic unit for controlling the speed of a main feed water pump, wherein:

[0018] The power operation logic unit is used to derive the input reactor power signal to obtain the power change rate of the reactor, and input the power change rate to the high value trigger logic unit;

[0019] The high value trigger logic unit is configured to send an intermediate signal indicating a large fluctuation of the reactor to the RS trigger logic unit when determining that the power change rate exceeds a change rate threshold;

[0020] The RS trigger logic unit is configured to generate a confirmation signal of a large reactor fluctuation according to the intermediate signal, and input the confirmation signal to the first switching logic unit and the second switching logic unit;

[0021] The first switching logic unit is configured to send a first control command to the main water supply regulating valve according to the confirmation signal, wherein the first control command is configured to instruct the main water supply regulating valve to adjust its opening to a preset opening threshold;

[0022] The second switching logic unit is configured to send a second control command to the main water supply pump according to the confirmation signal, wherein the second control command is configured to instruct the speed of the main water supply pump to be adjusted to a preset speed threshold;

[0023] The first liquid level trigger logic unit is configured to send a recovery signal indicating that the liquid level of the steam generator has recovered to the RS trigger logic unit when it is detected that the current liquid level of the steam generator meets a preset liquid level condition;

[0024] The RS trigger logic unit is further configured to input a reset signal to the first switching logic unit and the second switching logic unit according to the recovery signal;

[0025] The first switching logic unit is further configured to send a first reset control command to the main water supply regulating valve according to the reset signal, wherein the first reset control command is configured to instruct the main water supply regulating valve to be restored to an initial control mode to control the opening of the main water supply regulating valve;

[0026] The second switching switch logic unit is further used to send a second reset control command to the main water supply pump according to the reset signal, and the second reset control command is used to instruct to restore the initial control mode to control the speed of the main water supply pump.

[0027] In a third aspect, the present application provides an electronic device, comprising:

[0028] at least one processor; and

[0029] At least one memory having instructions stored thereon, which, when executed individually or collectively by the at least one processor, cause the electronic device to execute the method according to the first aspect.

[0030] In a fourth aspect, the present application provides a computer storage medium having instructions stored thereon, which, when executed individually or collectively by at least one processor of an electronic device, causes the electronic device to execute the method described in the first aspect.

[0031] The liquid level control method for a nuclear power plant steam generator provided in this application adjusts the opening of the main feedwater regulating valve to a preset opening threshold and the speed of the main feedwater pump to a preset speed threshold when the reactor power change rate exceeds a change rate threshold. The method also continuously monitors the current liquid level of the steam generator. When the current liquid level meets the preset liquid level condition, the method returns to the initial control mode to control the opening of the main feedwater regulating valve and the speed of the main feedwater pump. This method allows the main feedwater regulating valve and the speed of the main feedwater pump to be adjusted to their desired positions based on the preset opening and speed thresholds when the reactor experiences significant fluctuations, thus preventing the SG liquid level from losing control during repeated adjustments of the main feedwater regulating valve opening and the main feedwater pump speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the present application. They are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the accompanying drawings:

[0033] Figure 1 Schematic diagram of a liquid level control system for a steam generator in a nuclear power plant provided in an embodiment of the present application;

[0034] Figure 2 This is a flow chart of a method for controlling the liquid level of a steam generator in a nuclear power plant provided in an embodiment of the present application;

[0035] Figure 3 is a schematic diagram of a liquid level control device provided in an embodiment of the present application;

[0036] Figure 4 is a schematic diagram of another liquid level control device provided in an embodiment of the present application;

[0037] Figure 5 This is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0039] As used herein, unless the context clearly indicates otherwise, the terms "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0040] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0041] Unless otherwise specified, the relative arrangement of the parts and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. Technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0042] In addition, although the terms used in this application are selected from commonly known and commonly used terms, some of the terms mentioned in this specification may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description herein. In addition, it is required that this application be understood not only by the actual terms used, but also by the meaning implied by each term.

[0043] Flowcharts are used in this application to illustrate the operations performed by devices or apparatuses according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the various steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0044] In order to better understand the liquid level control method of a nuclear power plant steam generator proposed in this application, the liquid level control system of the steam generator to which this method is applied is introduced below. Figure 1The liquid level control system 10 may include two steam generators (steam generator No. 1 100 and steam generator No. 2 101), four main feedwater pumps 102, two main feedwater channels 103, two main feedwater regulating valves 104, and two main feedwater isolation valves 105. The main feedwater pump is used to deliver high-pressure feedwater to the steam generator through the main feedwater channel. The main feedwater pump uses variable frequency speed regulation to match steam demand in real time. For example, when the load increases, the speed increases to increase the feedwater pressure and flow rate, and when the load decreases, the speed decreases to avoid overpressure. The main feedwater regulating valve dynamically adjusts the opening according to the steam generator liquid level signal to regulate the feedwater flow rate. For example, when the liquid level is too high, the valve is closed to reduce the water supply, and when the liquid level is too low, the valve is opened to increase the flow rate. The main feedwater isolation valve is a key device to ensure the safe and reliable operation of the system. Its core function is to quickly cut off or connect the flow of the main feedwater channel. For example, when a steam generator leaks, a pipeline ruptures, or the main feedwater pump fails, the main feedwater isolation valve can be quickly closed to cut off the feedwater supply, preventing the steam generator liquid level from getting out of control due to the feedwater failure.

[0045] It can be understood that the number of steam generators, main feed water pumps, main feed water flow channels, main feed water regulating valves, and main feed water isolation valves in the above-mentioned liquid level control system 10 are all examples and do not constitute a specific limitation to the present application.

[0046] In a nuclear power plant, the steam generator is a key device between the reactor coolant system (not shown) and the steam turbine (not shown). The reactor cooling system generates heat through the fission reaction in the reactor core, heats the coolant (such as high-pressure water), and transmits it to the steam generator. The steam generator transfers heat to the secondary circuit working medium (water) through the tube wall, causing it to evaporate into high-temperature, high-pressure steam, which drives the steam turbine to generate electricity. Maintaining a stable liquid level in the steam generator is crucial. Precise control of the steam generator liquid level is directly related to the safety and operating efficiency of the nuclear power plant:

[0047] 1. Prevent steam from carrying water: If the liquid level is too high, saturated steam will carry water into the turbine, causing blade erosion, reduced efficiency, and even vibration failure;

[0048] 2. Avoiding exposed fuel rods: A low liquid level may cause insufficient reactor coolant, resulting in partial exposure of fuel rods to high temperatures, leading to the risk of core overheating or meltdown;

[0049] 3. System pressure balance: Liquid level fluctuations will directly affect the secondary circuit steam pressure and flow, thereby interfering with the turbine load response capability and destroying the stability of the thermal cycle;

[0050] 4. Safety protection linkage: abnormal liquid level may trigger emergency shutdown, reactor safety system activation and other protection actions, resulting in unplanned shutdown or equipment damage;

[0051] 5. Thermal efficiency optimization: A stable liquid level is a necessary condition for maintaining efficient heat exchange in the steam generator, which directly affects the conversion efficiency of nuclear energy → thermal energy → electrical energy.

[0052] Therefore, the core task of ensuring the safe, reliable and economical operation of the power plant is to adjust the feedwater flow in real time through the coordinated action of the main feedwater regulating valve opening and the main feedwater pump speed to ensure that the steam generator liquid level is always within the set range.

[0053] Based on this, this application proposes a liquid level control method for a nuclear power plant steam generator, see Figure 2 , the method can be applied to the above-mentioned liquid level control system 10, comprising the following steps:

[0054] S200: Acquire the power of the reactor.

[0055] S201: If the power change rate of the reactor detected according to the power exceeds the change rate threshold, the opening of the main feed water regulating valve is adjusted to a preset opening threshold, and the speed of the main feed water pump is adjusted to a preset speed threshold.

[0056] In the embodiment of the present application, the default state controls the opening of the main feedwater regulating valve and the speed of the main feedwater pump using an initial control mode. During the control process, reactor power is continuously collected, and the rate of change of the reactor power is calculated once each time the data is collected. If the rate of change of power does not exceed the rate of change threshold, indicating that the reactor has not experienced significant fluctuations, the initial control mode is maintained. If the rate of change of power exceeds the rate of change threshold, indicating that the reactor has experienced significant fluctuations, maintaining the initial control mode will cause the opening of the main feedwater regulating valve and the speed of the main feedwater pump to be repeatedly adjusted, failing to reach a convergence state, resulting in loss of control of the steam generator liquid level. Therefore, in this case, the opening of the main feedwater regulating valve can be directly adjusted to a preset opening threshold, and the speed of the main feedwater pump can be adjusted to a preset speed threshold. This only requires a single adjustment, eliminating the need for repeated adjustments of the opening of the main feedwater regulating valve and the speed of the main feedwater pump. This reduces the significant fluctuations of the main feedwater regulating valve and the main feedwater pump, thereby extending the service life of the equipment.

[0057] S202: Continuously monitor the current liquid level of the steam generator. When it is detected that the current liquid level meets the preset liquid level condition, restore to the initial control mode to control the opening of the main feed water regulating valve and the speed of the main feed water pump.

[0058] In one embodiment, after adjusting the opening of the main feedwater regulating valve to a preset opening threshold and the speed of the main feedwater pump to a preset speed threshold, the current liquid level of the steam generator can be continuously monitored. If the current liquid level is greater than or equal to the liquid level condition value, it is determined that the current liquid level meets the preset liquid level condition, and the initial control mode is restored to control the opening of the main feedwater regulating valve and the speed of the main feedwater pump. Alternatively, if the current liquid level is detected to be less than a lower liquid level limit (the lower liquid level limit is less than the liquid level condition value), a reactor shutdown signal is issued. Alternatively, if it is detected that the current liquid level is greater than or equal to the liquid level lower limit value and less than the liquid level condition value, the current liquid level of the steam generator will continue to be monitored, and the latest collected current liquid level will continue to be compared with the liquid level condition value and the above-mentioned liquid level lower limit value. According to the comparison results, the above-mentioned different processing is performed (restore to the initial control mode to control the opening of the main feed water regulating valve and the speed of the main feed water pump, send a reactor shutdown signal, or continue to monitor the current liquid level of the steam generator again), and so on, until the current liquid level is greater than or equal to the liquid level condition value, or less than the liquid level lower limit value. Among them, as a feasible method, if the continuous monitoring time exceeds the preset time, and the current liquid level is still less than the liquid level condition value, but not less than the liquid level lower limit value, an alarm message is output and the user manually verifies the cause.

[0059] As a feasible approach, the opening of the main feedwater regulating valve in the initial control mode is determined based on the feedwater demand flow rate, which is determined based on the steam generator's liquid level deviation and steam-water mismatch deviation. The liquid level deviation is the deviation between the steam generator's liquid level and the target liquid level, and the steam-water mismatch deviation is the deviation between the steam generator's steam flow rate and the feedwater flow rate. For example, in the initial control mode, when the feedwater demand flow rate increases, the opening of the feedwater regulating valve is increased until the actual feedwater flow rate equals the feedwater demand flow rate. When the feedwater demand flow rate decreases, the opening of the feedwater regulating valve is decreased until the actual feedwater flow rate equals the feedwater demand flow rate.

[0060] As a feasible approach, the speed of the main feedwater pump in the initial control mode is controlled based on the pressure difference between the steam main pipe corresponding to the steam generator and the outlet main pipe corresponding to the main feedwater pump. For example, when the pressure difference increases, the speed of the main feedwater pump is reduced until the actual pressure difference equals the set value; when the pressure difference decreases, the speed of the main feedwater pump is increased until the actual pressure difference equals the set value.

[0061] It is understood that the aforementioned rate-of-change threshold, preset opening threshold, preset speed threshold, liquid level condition value, lower liquid level limit, and set value can all be pre-set based on experimental data and can be a specific value or a range of values, and can be subsequently adjusted based on actual needs. For example, the rate-of-change threshold can be 50%, the preset opening threshold can be 70%, the preset speed threshold can be 95%, and the liquid level condition value can be 65%.

[0062] As a feasible approach, the method for determining the preset opening threshold and the preset speed threshold may include the following steps:

[0063] Step 1: Obtain the first operating parameter of the steam generator and the water density ρ at the main feed water pump pump , the second operating parameter of the reactor cooling system and the core heat generation q of the reactor corresponding to the reactor cooling system c Wherein, the first operating parameter includes any one or more of the following: water quality M of the steam generator SG , steam generator temperature T SG and designated parameters at various locations of the steam generator (e.g., SG inlet, outlet, internal, etc.); the second operating parameter includes any one or more of the following: reactor coolant system water quality M RCS , reactor coolant system temperature T RCS ;

[0064] Step 2: According to the first operating parameter, ρ pump , the second operating parameter, q c and a preset function to determine a preset opening threshold and a preset speed threshold.

[0065] In one embodiment, the above-mentioned specified parameters include any one or more of the following: water density ρ i , circulation area A i , along-the-line loss coefficient f i , length l i , hydraulic diameter d i , and the local loss coefficient k i , the preset functions include the following formulas:

[0066]

[0067] is the mass flow rate entering the steam generator, is the mass flow rate out of the steam generator, and is the steam generator pressure P SG function; g is the acceleration due to gravity (known value), H pump The head of the main water supply pump, and H pump yes and the function of the main feed water pump speed; P SG is the steam generator pressure, and P SG is the steam generator temperature T SG Function; CV valve The flow resistance of the main water supply regulating valve, and CV valve is a function of valve opening; H RCS is the enthalpy of the reactor coolant system, and H RCSis the reactor coolant system temperature T RCS function; h is the heat transfer coefficient (known value), A SG is the heat transfer area, and A SG is the steam generator water mass M SG function.

[0068] When executing the above step 2, the above first operating parameter, ρ pump , the second operating parameter, q c Substituting into Equations 1 to 3 yields a unique numerical relationship between valve opening and main feedwater pump speed. Multiple combinations exist that satisfy this numerical relationship. Subsequently, the optimal combination can be determined from all possible combinations, either manually by experts or through simulation software. The valve opening and pump speed in this optimal combination are then determined as the preset opening threshold and preset speed threshold, respectively.

[0069] As you can understand, Equations 1 through 3 comprehensively consider multiple key physical processes and parameters. First, Equation 1 describes the temporal evolution of water quality in the SG, which is related to the mass flow rate entering and exiting the SG. This lays the foundation for subsequent analysis of parameters such as SG pressure. Equation 2 is a key comprehensive equation that incorporates important parameters such as the main feedwater pump head, SG pressure, fluid losses along the pipeline (determined by parameters such as f, l, and d), and the flow resistance of the main feedwater regulating valve. This equation relates the energy (head) provided by the main feedwater pump to SG pressure, pipeline resistance losses, and valve flow resistance, reflecting the momentum balance relationship within the entire liquid level control system. Equation 3 describes the thermal balance of the reactor coolant system, taking into account factors such as core heat generation, heat transfer coefficient, heat transfer area, and the temperature difference between the reactor coolant system and the SG. This helps determine parameters such as SG temperature, which in turn affects SG pressure and is in turn correlated with the relationship between the main pump head and valve opening. In these formulas, valve opening directly affects the flow resistance of the main feedwater regulating valve, which, along with SG pressure, pipeline resistance, valve flow resistance, and other factors, satisfies the energy balance relationship. Therefore, based on these formulas, the relationship between valve opening and main feedwater pump speed can be accurately determined, providing a theoretical basis for the liquid level control of this application.

[0070] In an embodiment of the present application, when the rate of change of reactor power exceeds a rate of change threshold, the opening of the main feedwater regulating valve is adjusted to a preset opening threshold, the speed of the main feedwater pump is adjusted to a preset speed threshold, and the current liquid level of the steam generator is continuously monitored. When the current liquid level meets the preset liquid level condition, the initial control mode is restored to control the opening of the main feedwater regulating valve and the speed of the main feedwater pump. In this manner, when the reactor experiences severe fluctuations, the speed of the main feedwater regulating valve and the speed of the main feedwater pump can be adjusted to the desired position at once based on the preset opening threshold and the preset speed threshold, thus avoiding the situation where the SG liquid level is out of control during repeated adjustments of the opening of the main feedwater regulating valve and the speed of the main feedwater pump.

[0071] See also Figure 3 The present application proposes a steam generator liquid level control device 30 that can execute the above method. The device 30 includes a power operation logic unit 300, a high value trigger logic unit 301, a first liquid level trigger logic unit 302, an RS (set-reset) trigger logic unit 303, a first switch logic unit 304 for controlling the opening of the main feedwater regulating valve, and a second switch logic unit 305 for controlling the speed of the main feedwater pump, wherein:

[0072] The power operation logic unit 300 is used to derive the input reactor power signal to obtain the power change rate of the reactor and input the power change rate to the high value trigger logic unit 301.

[0073] The high value trigger logic unit 301 is used to send an intermediate signal representing a large fluctuation of the reactor to the RS trigger logic unit 303 when it is determined that the power change rate exceeds the change rate threshold.

[0074] The RS trigger logic unit 303 is used to generate a confirmation signal of a large reactor fluctuation according to the intermediate signal, and input the confirmation signal to the first switching logic unit 304 and the second switching logic unit 305.

[0075] The first switching logic unit 304 is used to send a first control command to the main water supply regulating valve according to the confirmation signal, where the first control command is used to instruct to adjust the opening of the main water supply regulating valve to a preset opening threshold.

[0076] The second switching logic unit 305 is used to send a second control command to the main water supply pump according to the confirmation signal, and the second control command is used to instruct to adjust the speed of the main water supply pump to a preset speed threshold.

[0077] The first liquid level trigger logic unit 302 is used to send a recovery signal indicating that the steam generator liquid level has recovered to the RS trigger logic unit 303 when it is detected that the current liquid level of the steam generator meets a preset liquid level condition (such as greater than or equal to the liquid level condition value).

[0078] The RS trigger logic unit 303 is further configured to input a reset signal to the first switch logic unit 304 and the second switch logic unit 305 according to the recovery signal.

[0079] The first switching switch logic unit 304 is further used to send a first reset control command to the main water supply regulating valve according to the reset signal, and the first reset control command is used to instruct to restore the opening of the main water supply regulating valve to the initial control mode.

[0080] The second switching logic unit 305 is further used to send a second reset control command to the main water supply pump according to the reset signal, and the second reset control command is used to instruct to restore the speed of the main water supply pump to the initial control mode.

[0081] In one embodiment, see Figure 4 The device 30 may further include a second liquid level trigger logic unit 306, a first NOT gate logic processing unit 307, an AND gate logic processing unit 308, a second NOT gate logic processing unit 309, and an OR gate logic processing unit 310. The first liquid level processing logic unit 302 is further configured to send a first low-level signal to the first NOT gate logic processing unit 307 when it detects that the current liquid level of the steam generator does not meet a preset liquid level condition (e.g., is less than a liquid level condition value). The first NOT gate logic processing unit 307 is configured to input a first high-level signal to the AND gate logic processing unit 308 based on the first low-level signal. The second liquid level processing logic unit 306 is configured to send a second high-level signal to the AND gate logic processing unit 308 when it detects that the current liquid level of the steam generator is less than a liquid level lower limit value. The AND gate logic processing unit 308 is configured to output a reactor shutdown signal upon receiving the first high-level signal and the second high-level signal. In this manner, a reactor shutdown signal can be output when the current liquid level of the steam generator does not meet the liquid level condition and is less than the liquid level lower limit value.

[0082] Alternatively, in another embodiment, the second liquid level processing logic unit 306 is further used to send a second low-level signal to the AND gate logic processing unit 307 when it is monitored that the current liquid level of the steam generator is greater than or equal to the lower limit value of the liquid level; the AND gate logic processing unit 307 is used to output a third low-level signal to the second NOT gate logic processing unit 309 when it receives a first high-level signal from the first NOT gate logic processing unit 307 and a second low-level signal from the second liquid level processing logic unit 306; the second NOT gate logic processing unit 309 is used to send a third high-level signal to the RS trigger logic unit through the OR gate logic processing unit 310 according to the third low-level signal; the RS trigger logic unit 303 is used to instruct the first switching switch logic unit 304 to send a first control command to the main feed water regulating valve and instruct the second switching switch logic unit 305 to send a second control command to the main feed water pump according to the third high-level signal.

[0083] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device can operate Figure 2 The liquid level control method of the nuclear power plant steam generator, or Figure 3 、 Figure 4 The liquid level control device, such as Figure 5 As shown, the electronic device includes an internal communication bus 501, a processor 502, a read-only memory (ROM) 503, a random access memory (RAM) 504, and a communication port 505. When used on a personal computer, the electronic device may also include a hard disk 506. The internal communication bus 501 can enable data communication between the components of the electronic device. The processor 502 can make judgments and issue prompts. In some embodiments, the processor 502 can be composed of one or more processors. The communication port 505 can enable data communication between the electronic device and the outside world. In some embodiments, the electronic device can send and receive information and data from a network via the communication port 505. The electronic device may also include program storage units and data storage units in various forms, such as a hard disk 506, a read-only memory (ROM) 503, and a random access memory (RAM) 504, which can store various data files used for computer processing and / or communication, as well as possible program instructions executed by the processor 502. The processor 502 executes these instructions to implement the main part of the method. The results of the processing by the processor 502 are transmitted to the electronic device via the communication port 505 and displayed on the user interface.

[0084] Processor 502 may be of any type suitable for the local technology network and may include, by way of non-limiting example, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. An electronic device may have multiple processors, such as application specific integrated circuit chips, which are slaved in time to a clock that synchronizes the master processor.

[0085] The processor 502 can be used to perform the following steps: obtain the power of the reactor, and if it is detected that the power change rate of the reactor exceeds the change rate threshold based on the power, adjust the opening of the main feed water regulating valve to a preset opening threshold, adjust the speed of the main feed water pump to a preset speed threshold, and continuously monitor the current liquid level of the steam generator. When it is monitored that the current liquid level meets the preset liquid level condition, restore to the initial control mode to control the opening of the main feed water regulating valve and the speed of the main feed water pump.

[0086] In one embodiment, after continuously monitoring the current liquid level of the steam generator, the processor 502 is further configured to issue a reactor shutdown signal if it is detected that the current liquid level is less than a lower liquid level limit.

[0087] In one embodiment, the processor 502 is further configured to obtain the first operating parameter of the steam generator, the water density ρ at the main feed water pump, pump , the second operating parameter of the reactor cooling system and the core heat generation q of the reactor corresponding to the reactor cooling system c ; Wherein, the first operating parameter includes any one or more of the following: water quality M of the steam generator SG , steam generator temperature T SG and designated parameters at various locations of the steam generator; the second operating parameter includes any one or more of the following: reactor coolant system water quality M RCS , reactor coolant system temperature T RCS ;

[0088] According to the first operating parameter, ρ pump , the second operating parameter, q c and a preset function to determine a preset opening threshold and a preset speed threshold.

[0089] In one embodiment, the processor 502 specifies that the specified parameters include any one or more of the following: water density ρ i , circulation area A i , along-the-line loss coefficient f i , length l i , hydraulic diameter d i , and the local loss coefficient k i , the preset function includes the following formula:

[0090]

[0091] in, is the mass flow rate entering the steam generator, is the mass flow rate out of the steam generator, and is the steam generator pressure P Sg function; g is the acceleration due to gravity, H pump The head of the main water supply pump, and H pump yes and the function of the main feed water pump speed; P SG is the steam generator pressure, and P SG is the steam generator temperature T SG Function; CV valve The flow resistance of the main water supply regulating valve, and CV valve is a function of valve opening; H RCS is the enthalpy of the reactor coolant system, and H TCS is the reactor coolant system temperature T RCS function; h is the heat transfer coefficient, A SGis the heat transfer area, and A SG is the steam generator water mass M SG function.

[0092] The above-mentioned liquid level control method for a nuclear power plant steam generator can be implemented as a computer program, stored in the hard disk 506, and loaded into the processor 502 for execution to implement the liquid level control method for a nuclear power plant steam generator of the present application.

[0093] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of any of the aforementioned methods for controlling the liquid level of a steam generator in a nuclear power plant are implemented.

[0094] The specific implementation methods and technical effects of the electronic device and computer-readable storage medium can be found in the embodiments of the liquid level control method for a nuclear power plant steam generator provided by the present invention, and will not be repeated here.

[0095] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of the two. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. A skilled person may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as resulting in a departure from the scope of the present invention.

[0096] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0097] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read and write information from / to the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside in a user terminal as discrete components.

[0098] In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, including any media that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks typically reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

Claims

1. A liquid level control method for a steam generator in a nuclear power plant, characterized in that: The method is applied to a liquid level control system of a steam generator, wherein the system includes a steam generator, a main feed water flow channel, a main feed water pump, and a main feed water regulating valve. The method includes: Get the power of the reactor; If the power change rate of the reactor detected according to the power exceeds a change rate threshold, adjusting the opening of the main feed water regulating valve to a preset opening threshold, and adjusting the speed of the main feed water pump to a preset speed threshold; continuously monitoring the current liquid level of the steam generator; When it is monitored that the current liquid level meets the preset liquid level condition, the initial control mode is restored to control the opening of the main water supply regulating valve and the speed of the main water supply pump.

2. The method according to claim 1, wherein After continuously monitoring the current liquid level of the steam generator, the method further includes: If it is detected that the current liquid level is less than the lower limit value of the liquid level, a reactor shutdown signal is issued.

3. The method according to claim 1, wherein The method further comprises: Obtain the first operating parameter of the steam generator and the water density ρ at the main feed water pump pump , the second operating parameter of the reactor cooling system and the core heat generation q of the reactor corresponding to the reactor cooling system c ; Wherein, the first operating parameter includes any one or more of the following: water quality M of the steam generator SG , steam generator temperature T SG and designated parameters at various locations of the steam generator; the second operating parameter includes any one or more of the following: reactor coolant system water quality M RCS , reactor coolant system temperature T RCS ; According to the first operating parameter, ρ pump , the second operating parameter, q c and a preset function to determine the preset opening threshold and the preset speed threshold.

4. The method according to claim 3, wherein The specified parameters include any one or more of the following: water density ρ i , circulation area A i , along-the-line loss coefficient f i , length l i , hydraulic diameter d i , and the local loss coefficient k i , the preset function includes the following formula: in, is the mass flow rate entering the steam generator, is the mass flow rate out of the steam generator, and is the steam generator pressure P SG function; g is the acceleration due to gravity, H pump The head of the main water supply pump, and H pump yes and the function of the main feed water pump speed; P SG is the steam generator pressure, and P SG is the steam generator temperature T SG Function; CV valve The flow resistance of the main water supply regulating valve, and CV valve is a function of valve opening; H RCS is the enthalpy of the reactor coolant system, and H RCS is the reactor coolant system temperature T RCS function; h is the heat transfer coefficient, A SG is the heat transfer area, and A SG is the steam generator water mass M SG function.

5. The method according to claim 1, wherein In the initial control mode, the opening of the main feed water regulating valve is controlled according to the feed water demand flow rate, and the feed water demand flow rate is determined based on the liquid level deviation and the steam-water mismatch deviation of the steam generator; wherein, the liquid level deviation is the deviation between the liquid level of the steam generator and the target liquid level, and the steam-water mismatch deviation is the deviation between the steam flow rate of the steam generator and the feed water flow rate; in the initial control mode, the speed of the main feed water pump is controlled according to the pressure difference between the steam main pipe corresponding to the steam generator and the outlet main pipe corresponding to the main feed water pump.

6. A steam generator liquid level control device, comprising a power operation logic unit, a high value trigger logic unit, a first liquid level trigger logic unit, an RS trigger logic unit, a first switch logic unit for controlling the opening of a main feedwater regulating valve, and a second switch logic unit for controlling the speed of a main feedwater pump, wherein: The power operation logic unit is used to derive the input reactor power signal to obtain the power change rate of the reactor, and input the power change rate to the high value trigger logic unit; The high value trigger logic unit is configured to send an intermediate signal indicating a large fluctuation of the reactor to the RS trigger logic unit when determining that the power change rate exceeds a change rate threshold; The RS trigger logic unit is configured to generate a confirmation signal of a large reactor fluctuation according to the intermediate signal, and input the confirmation signal to the first switching logic unit and the second switching logic unit; The first switching logic unit is configured to send a first control command to the main water supply regulating valve according to the confirmation signal, wherein the first control command is configured to instruct the main water supply regulating valve to adjust its opening to a preset opening threshold; The second switching logic unit is configured to send a second control command to the main water supply pump according to the confirmation signal, wherein the second control command is configured to instruct the speed of the main water supply pump to be adjusted to a preset speed threshold; The first liquid level trigger logic unit is configured to send a recovery signal indicating that the liquid level of the steam generator has recovered to the RS trigger logic unit when it is detected that the current liquid level of the steam generator meets a preset liquid level condition; The RS trigger logic unit is further configured to input a reset signal to the first switching logic unit and the second switching logic unit according to the recovery signal; The first switching logic unit is further configured to send a first reset control command to the main water supply regulating valve according to the reset signal, wherein the first reset control command is configured to instruct the main water supply regulating valve to be restored to an initial control mode to control the opening of the main water supply regulating valve; The second switching switch logic unit is further used to send a second reset control command to the main water supply pump according to the reset signal, and the second reset control command is used to instruct to restore the initial control mode to control the speed of the main water supply pump.

7. The device according to claim 6, characterized in that The device further includes a second liquid level trigger logic unit, a first NOT gate logic processing unit and an AND gate logic processing unit, wherein: The first liquid level processing logic unit is further configured to send a first low level signal to the first NOT gate logic processing unit when it is detected that the current liquid level of the steam generator does not meet a preset liquid level condition; The first NOT gate logic processing unit is configured to input a first high level signal to the AND gate logic processing unit according to the first low level signal; The second liquid level processing logic unit is configured to send a second high level signal to the AND gate logic processing unit when detecting that the current liquid level of the steam generator is less than the lower limit value of the liquid level; The AND gate logic processing unit is configured to output a reactor shutdown signal upon receiving the first high level signal and the second high level signal.

8. The device according to claim 6, wherein The device further includes a second liquid level trigger logic unit, a first NOT gate logic processing unit, an AND gate logic processing unit, and a second NOT gate logic processing unit, wherein: The first liquid level processing logic unit is further configured to send a first low level signal to the first NOT gate logic processing unit when it is detected that the current liquid level of the steam generator does not meet a preset liquid level condition; The first NOT gate logic processing unit inputs a first high level signal to the AND gate logic processing unit according to the first low level signal; The second liquid level processing logic unit is further configured to send a second low level signal to the AND gate logic processing unit when detecting that the current liquid level of the steam generator is greater than or equal to the lower liquid level limit; The AND gate logic processing unit is configured to output a third low level signal to the second NOT gate logic processing unit upon receiving the first high level signal and the second low level signal; The second NOT gate logic processing unit is configured to send a third high level signal to the RS trigger logic unit according to the third low level signal; The RS trigger logic unit is used to instruct the first switching switch logic unit to send the first control command to the main water supply regulating valve and instruct the second switching switch logic unit to send the second control command to the main water supply pump according to the third high-level signal.

9. An electronic device, characterized in that: include: at least one processor; as well as At least one memory having instructions stored thereon, wherein when the instructions are executed individually or collectively by the at least one processor, the electronic device executes the method according to any one of claims 1 to 5.

10. A computer storage medium, characterized in that The computer storage medium stores instructions, which, when executed individually or collectively by at least one processor of an electronic device, enable the electronic device to perform the method according to any one of claims 1 to 5.

Images