Steam generator water level control method, system and device based on digital twinning

Abstract

The invention discloses a steam generator water level control method, system and device based on digital twinning, and the method comprises the steps: obtaining the detection information obtained through the detection of a sensor in real time, and outputting the actual measurement water level to a water level regulator, so as to obtain the feed water flow regulation amount; the detection information is analyzed according to the real-time online heat balance model to obtain an analysis result, the analysis result and the feed water flow adjusting amount are output to a first flow regulator, and the first flow regulator correspondingly outputs a control instruction to a feed water adjusting valve for feed water flow adjustment. According to the control method, by means of the digital twinning technology and the numerical simulation technology, the water level control process is improved to achieve accurate adjustment, and the operation reliability, the equipment safety, the operation convenience and the operation efficiency of the nuclear power station steam generator are improved.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and in particular to a steam generator water level control method, system and device based on digital twin. Background Art

[0002] The steam generator is a key device in the steam supply system of a pressurized water reactor nuclear power plant, connecting the primary steam supply circuit (hereinafter referred to as the primary side or the first circuit) and the secondary steam supply circuit (hereinafter referred to as the secondary side or the second circuit). It undertakes the important function of heat and mass transfer. The coolant from the core transfers heat to the secondary circuit working fluid through the heat transfer tube and generates steam.

[0003] The water level control of the steam generator determines the safe, reliable and economical operation of the nuclear power plant units to a large extent. If the water level is too high, it will affect the steam-water separation effect, cause the steam quality to deteriorate, aggravate the erosion of the turbine, affect the life of the turbine and even damage the unit. Excessive water loading will also increase the mass loading of water in the steam generator. In the event of an accident condition where the steam pipe ruptures, excessive cooling of the core will occur, leading to a reactive accident. If the water level is too low, the top of the heat transfer tube may be exposed to the water surface. The water level fluctuation in this area will cause the heat transfer tube bundle to alternate between dry and wet and cause thermal stress fatigue. Too low a water level may also cause the water in the water supply pipeline to be emptied, which will then cause the risk of water hammer. Therefore, during the operation of a nuclear power plant, the water level of the steam generator must be maintained within a certain range.

[0004] The functions of the steam generator water level control system are: (1) to maintain the balance between the feed water flow and the steam flow under stable operating conditions so that the water level of the steam generator is within the specified range; (2) to keep the water level of the steam generator within the specified limit under transient conditions.

[0005] The working fluid on the secondary side of the steam generator undergoes single-phase convection heat transfer, subcooled boiling heat transfer and two-phase boiling heat transfer inside the steam generator. The descending channel is a single-phase fluid, and the ascending channel in the secondary tube bundle area is a two-phase mixture. There is a density wave instability phenomenon (Density Wave Oscillation) in the secondary natural circulation loop. The two-phase fluid flow and water level oscillate continuously with the fluctuation of the operating conditions, and there is a "contraction and expansion" phenomenon. This phenomenon is also called non-minimum phase dynamic phenomenon (Non-minimum Phase Dynamic), that is, when the operating conditions of the equipment change, the water level presents an instantaneous "inverse dynamic response", resulting in a "false water level". Its main manifestations are: when the feed water flow rate has a positive step, the water level of the steam generator initially shows a downward trend, and then slowly rises after a certain period of lag. This initial drop in the water level is called "false water level", and its amplitude depends on the size of the disturbance, and its lag time depends on the subcooling of the feed water. When the feed water temperature is lower, the lag time is greater. Conversely, when the feed water flow rate has a negative step change, the water level change law presents an opposite trend. When the steam flow rate has a positive step, the secondary side pressure decreases, and the two-phase mixture in the ascending channel of the tube bundle area expands, resulting in an increase in the two-phase flow resistance and a decrease in the flow rate in the descending channel, which in turn causes the secondary side water level to rise and a false water level phenomenon occurs. After the water level rises to a certain peak value, the water level decreases with the increase of steam load. This abnormal phenomenon that the water level does not decrease but increases significantly within a certain period of time after the load step increases is also a "false water level" phenomenon. When the steam flow rate has a negative step change, the water level characteristic changes show the opposite law.

[0006] The steam generator water level control system is a complex system with multiple variables, strong coupling, nonlinearity, time-varying and large hysteresis. Changes in reactor power, steam flow, feedwater temperature and flow rate will affect the water level on the secondary side of the steam generator. Therefore, the basic task of the feedwater level controller is to compensate for the water level changes caused by other factors by changing the feedwater flow rate, so that the secondary side water level is controlled within the target range. The main consequence of the long time hysteresis and shrinkage and expansion effect is that the feedwater controller must predict the impact of power plant state changes or control actions on the steam generator water level, and make a compensatory response before the final impact of the state change or action control on the steam generator water level is reflected in the measured water level.

[0007] Each of the steam generator feedwater lines is equipped with valves; a "low flow" or "bypass" valve is used for flow regulation at startup and low power conditions, and the valve is kept fully open at high power conditions. A "high flow" or "main valve" is used for flow regulation at conditions above about 20% thermal power.

[0008] The existing steam generator water level control system adopts a three-impulse water level control method with water level signal as the main adjustment input signal, steam flow as the supplementary signal, and feedwater flow as the negative feedback signal. The feedwater flow control valve opening is manually or automatically adjusted by continuously comparing the feedwater flow signal, liquid level signal and steam flow signal. Due to the phase difference and time lag between the steam flow or feedwater flow input signal and its corresponding water level output signal, the feedwater-water level control becomes extremely complicated. This is particularly serious under low-power platforms. Nuclear power plants have experienced many machine and reactor tripping incidents caused by loss of steam generator water level control, causing huge economic losses.

[0009] Therefore, the water level regulation accuracy of steam generators in existing nuclear power plants is insufficient when used under low power conditions. Summary of the invention

[0010] The embodiments of the present invention provide a steam generator water level control method, system and device based on digital twin, which aim to solve the problem of insufficient water level regulation accuracy of steam generators in existing nuclear power plants under low-power conditions.

[0011] In a first aspect, an embodiment of the present invention provides a steam generator water level control method based on digital twin, the control method is applied to a steam generator water level control system, the intelligent controller of the steam generator water level control system is communicatively connected with a sensor, a first flow regulator and a water level regulator provided in the steam generator, the first flow regulator is communicatively connected with a feed water regulating valve, wherein the control method comprises:

[0012] The intelligent controller acquires the detection information obtained by the sensor in real time;

[0013] The intelligent controller outputs the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount outputted correspondingly by the water level regulator;

[0014] The intelligent controller analyzes the primary side detection data and the secondary side detection data in the detection information according to a preset real-time online heat balance model to obtain corresponding analysis results; the primary side detection data is the detection data corresponding to the primary steam supply loop side in the detection information, and the secondary side detection data is the detection data corresponding to the secondary steam supply loop side in the detection information; the analysis results include a calculated value of feed water flow and a calculated value of steam flow;

[0015] The intelligent controller outputs the analysis result and the water supply flow adjustment amount to the first flow regulator;

[0016] The first flow regulator correspondingly outputs a control instruction to the water supply regulating valve to regulate the water supply flow.

[0017] In the second aspect, the embodiment of the present application further provides a steam generator water level control system based on digital twin, wherein the steam generator water level control system is used to execute the steam generator water level control method based on digital twin as described in the first aspect above, and the steam generator water level control system includes a detection information acquisition unit configured in the intelligent controller, a first information output unit, a judgment unit, an analysis result acquisition unit, a second information output unit, a simulation calculation result acquisition unit, a third information output unit, and a control instruction output unit configured in the first flow regulator;

[0018] The detection information acquisition unit is used to acquire the detection information obtained by the sensor in real time;

[0019] The first information output unit is used to output the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount outputted correspondingly by the water level regulator;

[0020] The analysis result acquisition unit is used to analyze the primary side detection data and the secondary side detection data in the detection information according to a preset real-time online heat balance model to obtain corresponding analysis results; the primary side detection data is the detection data corresponding to the primary steam supply loop side in the detection information, and the secondary side detection data is the detection data corresponding to the secondary steam supply loop side in the detection information; the analysis result includes a calculated value of feed water flow and a calculated value of steam flow;

[0021] The second information output unit is used to output the analysis result and the water supply flow adjustment amount to the first flow regulator;

[0022] The control instruction output unit is used to output a corresponding control instruction to the water supply regulating valve to regulate the water supply flow rate.

[0023] In a third aspect, an embodiment of the present application further provides a steam generator water level control device based on digital twin, wherein the steam generator water level control device includes an intelligent controller, a sensor, a first flow regulator, a water level regulator, a feedwater regulating valve, a second flow regulator, and a feedwater pump speed regulator;

[0024] One end of the water supply main pipe is connected to the output port of the first water supply pump, and the other end is connected to the water supply input end of at least one steam generator; the water supply regulating valve is arranged in series on one side of the water supply main pipe close to the water supply input end; each steam generator is connected to the steam turbine through the steam main pipe;

[0025] The sensors include a differential pressure sensor, a steam pressure sensor, a main pipe pressure sensor, a water supply sensor, a water supply flow sensor, a water outlet sensor and a steam flow sensor;

[0026] The two detection ends of the differential pressure sensor are respectively connected to the two pressure detection ports of one of the steam generators, and the signal output end of the differential pressure sensor is connected to the intelligent controller; the detection end of the steam pressure sensor is connected to the steam main pipe, and the signal output end of the steam pressure sensor is connected to the intelligent controller; the detection end of the main pipe pressure sensor is connected to the water supply main pipe, and the signal output end of the main pipe pressure sensor is connected to the intelligent controller;

[0027] The detection end of the water supply sensor is connected to the water supply pipe of the steam generator, and the signal output end of the water supply sensor is connected to the intelligent controller; the detection end of the water outlet sensor is connected to the drain pipe of the steam generator, and the signal output end of the water outlet sensor is connected to the intelligent controller; the detection end of the steam flow sensor is connected to the steam main pipe, and the signal output end of the steam flow sensor is connected to the intelligent controller; the detection end of the water supply flow sensor is connected to the water supply main pipe and the connection point is located upstream of the water supply regulating valve, and the signal output end of the water supply flow sensor is connected to the intelligent controller;

[0028] The intelligent controller is in communication connection with each sensor, the first flow regulator, the water level regulator and the second flow regulator; the first flow regulator is in communication connection with the water supply regulating valve; the second flow regulator is in communication connection with the water supply pump speed regulator;

[0029] The intelligent controller includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0030] Memory, used to store computer programs;

[0031] The processor is used to implement the steam generator water level control method based on digital twin as described in the first aspect above when executing the program stored in the memory.

[0032] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the steam generator water level control method based on digital twin as described in the first aspect are implemented.

[0033] The embodiment of the present invention provides a steam generator water level control method, system and device based on digital twin, which obtains the detection information obtained by the sensor in real time and outputs the actual measured water level therein to the water level regulator to obtain the feedwater flow regulation amount; the detection information is analyzed according to the real-time online thermal balance model to obtain the analysis result, and the analysis result and the feedwater flow regulation amount are output to the first flow regulator, and the first flow regulator correspondingly outputs the control instruction to the feedwater regulating valve to regulate the feedwater flow. The above control method, with the help of digital twin technology and numerical simulation technology, improves the water level control process of the steam generator to achieve accurate regulation, thereby further improving the operating reliability, equipment safety, operational convenience and operating efficiency of the steam generator of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0035] Figure 1 This is the application effect diagram of the steam generator water level control in the existing design;

[0036] Figure 2 A method flow chart of a steam generator water level control method based on digital twin provided in an embodiment of the present invention;

[0037] Figure 3 A schematic block diagram of a steam generator water level control system based on digital twin provided in an embodiment of the present invention;

[0038] Figure 4 An application effect diagram of a steam generator water level control device based on digital twin provided in an embodiment of the present invention;

[0039] Figure 5 Another application effect diagram of the steam generator water level control device based on digital twin provided by an embodiment of the present invention;

[0040] Figure 6 A schematic block diagram of a computer device provided in an embodiment of the present invention.

[0041] Attached figure markings: S, intelligent controller; R2, first flow regulator; R1, water level regulator; V1, water supply regulating valve; R3, second flow regulator; V2, water supply pump speed regulator; N, differential pressure sensor; P1, steam pressure sensor; P2, main pipe pressure sensor; Qs, water supply sensor; Qa, water supply flow sensor; Qw, water outlet sensor; Qv, steam flow sensor; B1, first water supply pump. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0044] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0045] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0046] See also Figure 1 , Figure 1 The following is an application effect diagram of the water level control of the steam generator in the prior art, which includes water level regulation and feedwater pump speed regulation. The actual water level of the steam generator is measured by the differential pressure sensor N and input into the water level regulator R1 together with the water level setting value. The output signal of R1 represents the feedwater flow adjustment corresponding to the deviation between the actual water level and the set water level. The steam flow and feedwater flow are respectively measured by the steam flow sensor Q v And water flow sensor Q aThe difference (i.e., steam-water mismatch signal) is measured and input into the first flow regulator R2 as a feedforward signal together with the output of the water level regulator R1. The purpose of incorporating the feedforward signal into the first flow regulator R2 is to speed up the regulation speed, because the imbalance between the steam flow and the feedwater flow will cause the water level to change. The output of the first flow regulator R2 corresponds to the change in the opening of the feedwater valve required by the above-mentioned flow regulator, and is sent to the feedwater regulating valve V1 to make it operate, thereby changing the feedwater flow.

[0047] However, the change of feedwater flow rate will lead to the change of feedwater pump outlet pressure head, which affects the feedwater volume of the other two parallel steam generators, and then affects their water level. In addition, in order to ensure the regulating characteristics of the feedwater valve V1, the valve opening should also be kept at a moderate position, so it is required to keep the pressure difference before and after the valve as a constant value. In the actual operation of the nuclear power plant, when the pressure difference ΔP between the feedwater main pipe and the steam main pipe changes according to a certain function with the secondary circuit load, the pressure difference before and after the regulating valve can be maintained constant. Therefore, the pressure difference setting value ΔP0 between the feedwater main pipe and the steam main pipe calculated by the total steam flow is compared with the measured value ΔP to obtain a comparison signal output to the second flow regulator R3. The second flow regulator R3 outputs a signal to the feedwater pump speed regulator V2 according to the deviation size and direction of the comparison signal, changes the speed of the feedwater pump, and keeps the pressure difference before and after the feedwater pump speed regulator V2 unchanged.

[0048] Existing technology: using water level, steam flow Q v and water flow rate Q a The three-impulse water level regulation method for the input signal uses the water level signal as the main regulation input signal, the steam flow rate as the supplementary signal, and the feed water flow rate signal as the negative feedback. The water level regulation system of the prior art adopts a PID regulator, which is a cascade feedforward control system. The system has high requirements for the accuracy of the measurement value.

[0049] Under high power conditions with a power greater than 30%, the steam flow and feed water flow are large. The measurement accuracy of the Venturi tube flow transmitter on the main feed water pipeline and the differential pressure flow transmitter on the steam pipeline is high. By continuously comparing the feed water flow signal, liquid level signal and steam flow signal, the main valve opening can be accurately adjusted for flow, and the steam generator water level regulation performance is good.

[0050] However, the prior art 1 has poor water level regulation performance under low power conditions. During low power operation with power less than 30%, due to low steam flow and feed water flow, the measurement deviation of steam and feed water flow transmitters is large. At lower flow, the steam and feed water flow measurement signals are unavailable, which has a great impact on the control system. Under low power conditions, the prior art relies on the "manual operation" of the nuclear power plant operator, who manually adjusts the water level by adjusting the opening of the bypass valve.

[0051] Under low power conditions, the natural circulation loop on the secondary side of the steam generator has a more obvious density wave instability phenomenon. The phase difference between the flow at the bottom of the descending channel and the flow at the outlet of the ascending channel exceeds 180 degrees. The water level becomes unstable with the fluctuation of the operating conditions, and the water level control is difficult. The "contraction and expansion" phenomenon makes it difficult for operators to judge the impact of the feedwater valve action on the water level change. It is easy to often provide a large amount of feedwater signal to the feedwater valve when it should not be fed, causing the water level to exceed the maximum water level line, or not inject enough feedwater in time when it should be fed, causing the water level line to be too low. There have been dozens of nuclear power plant trips and reactor trips caused by loss of water level control, causing huge economic losses.

[0052] In summary, the existing steam generator water level control system has the following deficiencies: (1) Under low power conditions, due to the low steam flow and feed water flow, the measurement deviation of the steam and feed water flow transmitters is large. At lower flow rates, the steam and feed water flow measurement signals are unavailable, the water level regulation performance is poor, and the operator is required to perform "manual operation" by the nuclear power plant operator, which requires high experience and level of the operator. (2) At low power platforms, water level control is difficult. The operator controls the feed water flow through false water levels and experience. The false water level easily interferes with the operator's judgment and causes misoperation, making it difficult to adjust the steam generator water level to a safe range in a timely and accurate manner. (3) The existing system will only generate an alarm signal after the water level has deviated from the normal threshold or lost control, and the alarm signal cannot provide the operator with a corresponding indication response. (4) When a sensor in the nuclear power plant steam generator water level control system fails, it will affect the water level control signal, thereby affecting the safe operation of the nuclear power plant.

[0053] See also Figure 2 As shown in the figure, the embodiment of the present application discloses a steam generator water level control method based on digital twin. Please refer to the application effect diagram of 4. The steam generator water level control method is based on Figure 4 The pipeline structure shown realizes the corresponding water level control function; specifically, the method is applied to the steam generator water level control system, and the method is executed by the application software installed in the steam generator water level control system; the intelligent controller is communicated with each sensor, the first flow regulator and the water level regulator in the steam generator, and the first flow regulator establishes a communication connection with the feed water regulating valve. Figure 4In the piping structure shown, multiple steam generators can be connected at the same time, and each steam generator is connected to the steam main pipe and the water supply main pipe; the steam generators are represented by SG1, SG2 and SG3 respectively. Among them, the intelligent controller is a processor used to issue control instructions to control each component, such as a programmable logic controller (PLC) or other terminal devices, such as laptops, desktop computers, tablet computers or mobile phones. The above control method is mainly based on the description of controlling the water level of a steam generator. In actual application, the control method can control the water levels of multiple steam generators at the same time.

[0054] like Figure 1 As shown, the method includes steps S101 to S105.

[0055] S101, the intelligent controller acquires detection information obtained by the sensor in real time.

[0056] The intelligent controller acquires the detection information obtained by the sensor in real time. The sensor detects the pipeline connected to the steam generator, thereby obtaining corresponding detection information and sending it to the intelligent controller, and the intelligent controller can obtain the detection information.

[0057] S102: The intelligent controller outputs the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount outputted correspondingly by the water level regulator.

[0058] The intelligent controller outputs the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount corresponding to the output of the water level regulator. The intelligent controller outputs the actual measured water level in the detection information to the water level regulator, wherein the actual measured water level is measured by the differential pressure sensor, and the actual measured water level is input into the water level regulator together with the preset water level setting value; then the water level regulator outputs the water supply flow adjustment amount according to the actual measured water level and the water level setting value, and the water supply flow adjustment amount is also expressed as the value corresponding to eliminating the deviation between the actual measured water level and the set water level.

[0059] In a more specific embodiment, step S102 specifically includes the following steps: the intelligent controller outputs the actual measured water level in the detection information to the water level regulator; the water level regulator compares the actual measured water level with the set water level setting value, obtains the corresponding water supply flow adjustment amount and outputs it to the intelligent controller.

[0060] Specifically, the intelligent controller outputs the actual measured water level in the detection information to the water level regulator, and the water level regulator compares the actual measured water level with the set water level setting value to obtain the water supply flow adjustment amount and output it to the intelligent controller.

[0061] S103, the intelligent controller analyzes the primary side detection data and the secondary side detection data in the detection information according to a preset real-time online thermal balance model to obtain corresponding analysis results.

[0062] The intelligent controller analyzes the primary side detection data and the secondary side detection data in the detection information according to the preset real-time online heat balance model to obtain the corresponding analysis results. The detection information includes the primary side detection data (corresponding to the first circuit) and the secondary side detection data (corresponding to the second circuit); the primary side detection data is the detection data corresponding to the primary steam supply circuit side in the detection information, and the secondary side detection data is the detection data corresponding to the secondary steam supply circuit side in the detection information; the analysis results include the calculated value of the feed water flow rate and the calculated value of the steam flow rate.

[0063] In a more specific embodiment, step S103 specifically includes the following steps: constructing a first relationship between the heat exchange power of the steam generator and the steam flow rate and the feed water flow rate according to the real-time line heat balance model; constructing a second relationship between the steam flow rate and the feed water flow rate according to the water supply and drainage balance relationship; substituting the known quantities in the primary side detection data and the secondary side detection data into the first relationship and the second relationship for analysis to obtain corresponding analysis results.

[0064] Specifically, the real-time line heat balance model includes Q=C p W×(T hot -T cold )and Wherein, Q is the heat exchange power of the steam generator, C p is the volume specific heat capacity, W is the primary side coolant flow rate, T hot and T cold are the inlet and outlet coolant temperatures of the primary side, Q2 is the heat exchange power between the primary side and the secondary side of the steam generator, A S is the heat transfer area, K is the total heat transfer coefficient, T sat is the saturation temperature.

[0065] The heat exchange power Q of the steam generator and the flow rate, pressure, temperature, etc. of the inlet and outlet pipes on the primary side have the following relationship: Q = C p W×(T hot -T cold ). C pis the volume specific heat capacity, which is a function of the primary side pressure and temperature and can be obtained by querying the international standard for the thermodynamic properties of water and water vapor IAPWS-IF97. W is the primary side coolant flow rate, which is calibrated in the "Steam Generator Margin Verification Test" project after the first loading of the reactor. Since the speed of the reactor coolant pump remains unchanged when operating at rated conditions, this technical solution can directly use the flow rate calibrated in the steam generator margin verification test. T hot and T cold are the inlet and outlet coolant temperatures of the primary side, respectively, which are measured online in real time by the measuring instrument, that is, the detection information includes T hot and T cold The specific value of .

[0066] The heat transfer power Q2 of the primary and secondary sides of the steam generator and the heat transfer area A of the heat transfer tube S There is also the following relationship between the primary and secondary side temperatures: Where K is the total heat transfer coefficient, T sat is the saturation temperature, and its value can be obtained according to the international standard IAPWS-IF97 on the thermodynamic properties of water and water vapor.

[0067] Among them, the calculation formula of the total heat transfer coefficient is: h p is the primary side heat transfer coefficient, U t is the thermal conductivity of the heat transfer tube, U f is the fouling heat transfer coefficient, h s is the secondary side heat transfer coefficient. The primary side of the heat transfer tube is the forced convection heat transfer of the single-phase fluid in the tube, and the secondary side heat transfer outside the heat transfer tube can be considered as large space boiling heat transfer, which is calculated using the Dittus-Boelter and its modified formula and the Rohsenow large space boiling heat transfer formula.

[0068] Furthermore, the first relational expression is Q=W s ((1-x)H s +xH l )+W p H l -W f H f ; W s is the steam flow rate, W p is the secondary side sewage flow, W f is the water flow rate, H s Saturated steam enthalpy, H l Saturated water enthalpy, H f The feed water enthalpy value, x is the humidity percentage in the steam; the second relationship is W f =W s +W p .

[0069] According to the heat balance model, the water flow rate W can be calculated f The corresponding calculated feed water flow rate and steam flow rate W s The corresponding calculated value of steam flow provides the necessary input parameters for the water level control system.

[0070] S104: The intelligent controller outputs the analysis result and the water supply flow adjustment amount to the first flow regulator.

[0071] If the operating conditions are met, the intelligent controller outputs the analysis result and the water supply flow adjustment amount to the first flow regulator.

[0072] In a more specific embodiment, the following steps are also included before step S104: the intelligent controller determines whether the reactor power in the detection information meets the preset operating conditions; if the operating conditions are met, the intelligent controller executes the step of outputting the analysis results and the water feed flow adjustment amount to the first flow regulator; if the operating conditions are not met, the intelligent controller simulates the detection information according to a preset simulation model to obtain corresponding simulation calculation results; the simulation calculation results include the water level change trend and the water level change amplitude range; the intelligent controller outputs the simulation calculation results and the water feed flow adjustment amount to the first flow regulator, so that the first flow regulator outputs the control instructions to the water feed regulating valve to adjust the water feed flow.

[0073] If the operating conditions are met, continue to step S140.

[0074] The intelligent controller determines whether the reactor power in the detection information meets the preset operating conditions. The intelligent controller obtains the reactor power from the detection information and determines whether the reactor power meets the operating conditions.

[0075] In a more specific embodiment, the determination of whether the reactor power in the detection information satisfies the preset operating condition specifically includes the following steps: determining whether the reactor power in the detection information is in a high-power condition; determining whether the reactor power in the detection information is in a stable operating condition; if the reactor power is in a high-power condition and is in a stable operating condition, determining that the operating condition is satisfied; if the reactor power is not in a high-power condition or is not in a stable operating condition, determining that the operating condition is not satisfied.

[0076] Specifically, the reactor power can be obtained from the detection information, and it can be determined whether the reactor power is in a high-power condition; wherein, the power corresponding to the high-power condition is not less than 30% Pn, and Pn is the full power of the reactor. If the reactor power is not less than 30% Pn, it is determined to be in a high-power condition; if the reactor power is less than 30% Pn, it is determined not to be in a high-power condition. It is further determined whether the reactor power is in a stable operating condition, wherein the stable operating condition corresponds to a power change of no more than 10% FP / min, and 10% FP / min is a power increase or decrease of 5% of the full power per minute. If the rate of change of the reactor power is no more than 10% FP / min, it is determined to be a stable operating condition; if the rate of change of the reactor power is greater than 10% FP / min, it is determined not to be a stable operating condition.

[0077] If the operating condition is not met, the intelligent controller performs simulation calculation on the detection information according to a preset simulation model to obtain corresponding simulation calculation results. The simulation calculation results include the water level change trend and the water level change amplitude range.

[0078] In a more specific embodiment, the simulation calculation of the detection information according to a preset simulation model specifically includes the following steps: dividing the steam generator into control bodies according to the division rules in the simulation model to obtain corresponding control body division results; calculating each control body in the control body division results according to the control equations in the simulation model to obtain physical properties of each control body; solving and calculating the physical properties of each control body according to the gas-liquid conservation equations in the simulation model to obtain corresponding simulation calculation results.

[0079] The steam generator, the primary circuit, and the secondary circuit can be divided according to the division rules set in the simulation model to obtain the control volume division results. The division rules include whether the cavity is an internal cavity, whether the cavity has a flowing fluid, whether the cavity has an inflow interface and an outflow interface, etc. If the judgment results are all yes, the cavity is divided into a control volume. The control volume division results are as follows Figure 5 As shown, the steam chamber corresponds to one control body, numbered "(1)", the separator corresponds to two control bodies, numbered "(2)" and "(3)", and so on. The pipeline above the primary side inlet corresponds to twelve control bodies numbered 1-12, and the pipeline above the primary side outlet corresponds to twelve control bodies numbered 13-24.

[0080] Furthermore, each control volume included in the control volume division result is calculated respectively according to the control equation in the simulation model, so as to obtain the physical property parameters of the control volume.

[0081] Specifically, the control equation includes: M is the mass of the control body; U is the energy of the control body; W is the mass flow rate of the flow channel; S is the flow cross section of the flow channel; ∑Q ST is the generalized source term; L is the flow channel length; Δp f is the friction pressure drop; Δp s is the local pressure drop; Δp g is the pressure drop at the gravity position; Δp a is the acceleration pressure drop; h is the specific enthalpy; the subscripts i and j are the control body numbers, k is the flow channel number between the control bodies, in is the flow into the control body, out is the flow out of the control body, and ex is the flow rate between the control body and the external interface.

[0082] The pressure, specific enthalpy, mass in the control volume and the mass flow rate in the flow channel can be obtained by the above control equation. i The physical parameters are determined according to the international standard IAPWS-IF97 for the thermodynamic properties of water and water vapor. The relevant relationship can be expressed as v i =f(p i ,h i );where v i is the specific volume of control body i; p i is the pressure of control volume i.

[0083] When there is water level in the control body, the cavitation fraction in the upper and lower regions of the control body is discontinuous, the lower region may be in a cold water state or a saturated two-phase state, and the upper region may be in a superheated steam state or a saturated two-phase state containing droplets. In the transient process, the upper and lower regions expand and contract with the change of water level, and the gas-liquid conservation equations are established for the upper and lower regions respectively in the transient numerical model. By solving the control equations for the lower region of the control body with water level, the technical invention can track the water level changes on the secondary side of the steam generator, thereby identifying the false water level phenomenon; the corresponding gas-liquid conservation equation is A is the flow cross section of the control body, v is the specific heat capacity of the control body, WL is the water level in the control body, and the subscript un is the lower area of ​​the control body with water level.

[0084] Furthermore, the intelligent controller outputs the simulation calculation result and the water supply flow adjustment amount to the first flow regulator, so that the first flow regulator outputs a control instruction to the water supply regulating valve to adjust the water supply flow. Similarly, the first flow regulator R2 generates a corresponding control instruction according to the received simulation calculation result and the water supply flow adjustment amount, and outputs the control instruction to the water supply regulating valve.

[0085] S105. The first flow regulator outputs a control instruction to the water supply regulating valve to regulate the water supply flow.

[0086] The first flow regulator outputs a corresponding control instruction to the water supply regulating valve to adjust the water supply flow. The first flow regulator R2 generates a corresponding control instruction based on the received analysis result and the water supply flow adjustment amount, and outputs the control instruction to the water supply regulating valve; then the control instruction output by the first flow regulator R2 can correspond to the valve opening change of the water supply regulating valve, and the control instruction is output to the water supply regulating valve V1 to make it act, thereby changing the water supply flow.

[0087] In a more specific embodiment, the steam generator also includes a second flow regulator and a feed water pump speed regulator, the second flow regulator is communicatively connected to the intelligent controller, and the second flow regulator establishes a communication connection with the feed water pump speed regulator; the above-mentioned control method also includes the following steps: the intelligent controller obtains the feed water main pipe pressure value and the steam main pipe pressure value in the detection information to perform a differential operation to obtain a corresponding pressure difference measurement value; the intelligent controller inputs the pressure difference measurement value to the second flow regulator; the second flow regulator compares the pressure difference measurement value with the set pressure difference setting value, and outputs a control instruction to the feed water pump speed regulator to adjust the water pump speed according to the comparison result.

[0088] The specific working principle is as follows Figure 4 As shown, the pressure difference setting value between the water supply main pipe and the steam main pipe can be set to ΔP0. The intelligent controller performs a differential operation on the water supply main pipe pressure value and the steam main pipe pressure value in the detection information to obtain the corresponding pressure difference measurement value ΔP. The intelligent controller inputs the pressure difference measurement value to the second flow regulator. The second flow regulator compares the pressure difference measurement value ΔP and the pressure difference setting value ΔP0. The second flow regulator outputs a control instruction to the water pump speed regulator according to the deviation size and direction of the two values, thereby changing the speed of the water supply pump so that the pressure difference before and after the water pump speed regulator V2 remains unchanged.

[0089] The steam generator water level control method based on digital twin disclosed in the above embodiment includes: acquiring the detection information obtained by the sensor in real time and outputting the actual measured water level therein to the water level regulator to obtain the feedwater flow regulation amount; parsing the detection information according to the real-time online heat balance model to obtain the analysis result, outputting the analysis result and the feedwater flow regulation amount to the first flow regulator, and the first flow regulator correspondingly outputs the control instruction to the feedwater regulating valve to regulate the feedwater flow. The above control method, with the help of digital twin technology and numerical simulation technology, improves the water level control process of the steam generator to achieve accurate regulation, thereby further improving the operating reliability, equipment safety, operational convenience and operating efficiency of the steam generator of the nuclear power plant.

[0090] The embodiment of the present invention further provides a steam generator water level control system based on digital twin, and the steam generator water level control system based on digital twin is used to execute the control method described in the above embodiment, such as Figure 3 As shown, the steam generator water level control system includes a detection information acquisition unit 101 configured in the intelligent controller, a first information output unit 102, an analysis result acquisition unit 103, a second information output unit 104, and a control instruction output unit 105 configured in the first flow regulator.

[0091] The detection information acquisition unit 101 is used to acquire the detection information obtained by the sensor in real time.

[0092] The first information output unit 102 is used to output the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount outputted correspondingly by the water level regulator.

[0093] The analysis result acquisition unit 103 is used to analyze the primary side detection data and the secondary side detection data in the detection information according to a preset real-time online heat balance model to obtain corresponding analysis results; the primary side detection data is the detection data corresponding to the primary steam supply loop side in the detection information, and the secondary side detection data is the detection data corresponding to the secondary steam supply loop side in the detection information; the analysis results include the calculated value of the feed water flow rate and the calculated value of the steam flow rate.

[0094] The second information output unit 104 is used to output the analysis result and the water supply flow adjustment amount to the first flow regulator.

[0095] The control instruction output unit 105 is used to output a control instruction to the water supply regulating valve to adjust the water supply flow rate.

[0096] The steam generator water level control system based on digital twin provided in the embodiment of the present invention applies the above-mentioned steam generator water level control method based on digital twin, obtains the detection information obtained by sensor detection in real time and outputs the actual measured water level therein to the water level regulator to obtain the feedwater flow regulation amount; analyzes the detection information according to the real-time online thermal balance model to obtain the analysis result, outputs the analysis result and the feedwater flow regulation amount to the first flow regulator, and the first flow regulator correspondingly outputs the control instruction to the feedwater regulating valve to regulate the feedwater flow. The above-mentioned control method, with the help of digital twin technology and numerical simulation technology, improves the water level control process of the steam generator to achieve accurate regulation, thereby further improving the operating reliability, equipment safety, operational convenience and operating efficiency of the steam generator of the nuclear power plant.

[0097] The present application also discloses a steam generator water level control device based on digital twin, wherein, Figure 4 As shown, the steam generator water level control device includes an intelligent controller S, a sensor, a first flow regulator R2, a water level regulator R1, a feed water regulating valve V1, a second flow regulator R3 and a feed water pump speed regulator V2; one end of the feed water main pipe is connected to the output port of the first feed water pump, and the other end is connected to the feed water input end of at least one steam generator; the feed water regulating valve V1 is arranged in series on one side of the feed water main pipe close to the feed water input end; each of the steam generators is connected to the steam turbine through a steam main pipe; the sensor includes a differential pressure sensor N, a steam pressure sensor The steam main pipe is connected to the steam generator by a pressure sensor P1, a main pipe pressure sensor P2, a feed water sensor Qs, a feed water flow sensor Qa, a water outlet sensor Qw and a steam flow sensor Qv; the two detection ends of the differential pressure sensor N are respectively connected to the two pressure detection ports of the steam generator, and the signal output end of the differential pressure sensor N is connected to the intelligent controller S; the detection end of the steam pressure sensor P1 is connected to the steam main pipe, and the signal output end of the steam pressure sensor P1 is connected to the intelligent controller S; the detection end of the main pipe pressure sensor P2 is connected to the feed water sensor Qs, the feed water flow sensor Qa, the water outlet sensor Qw and the ... The water main pipe is connected, and the signal output end of the main pipe pressure sensor P2 is connected to the intelligent controller S; the detection end of the water supply sensor Qs is connected to the water supply pipe of the steam generator, and the signal output end of the water supply sensor Qs is connected to the intelligent controller S; the detection end of the water outlet sensor Qw is connected to the drain pipe of the steam generator, and the signal output end of the water outlet sensor Qw is connected to the intelligent controller S; the detection end of the steam flow sensor Qv is connected to the steam main pipe, and the signal output end of the steam flow sensor Qv is connected to the intelligent controller S; the detection end of the water supply flow sensor Qa is connected to the water supply main pipe and the connection point is located upstream of the water supply regulating valve V1, and the signal output end of the water supply flow sensor Qa is connected to the intelligent controller S; the intelligent controller S is communicated with each sensor, the first flow regulator R2, the water level regulator R1 and the second flow regulator R3, and the first flow regulator R2 establishes a communication connection with the water supply regulating valve V1; the second flow regulator R3 establishes a communication connection with the water supply pump speed regulator V2.

[0098] Among them, the steam pressure sensor P1 is used to measure the steam main pipe pressure value, and the main pipe pressure sensor P2 is used to measure the water supply main pipe pressure value. The steam flow sensor Qv is used to measure the steam flow, and the water supply flow sensor Qa is used to measure the water supply flow. The water supply sensor Qs is used to measure the flow, pressure, temperature and other values ​​of the inlet pipe on the primary side, and the water outlet sensor Qw is used to measure the flow, pressure, temperature and other values ​​of the outlet pipe on the primary side;

[0099] Furthermore, the input port of the first water supply pump B1 is connected to the output port of the water supply pump speed regulator V2, and the input port of the water supply pump speed regulator V2 is used for water intake.

[0100] The above-mentioned steam generator water level control system based on digital twin can be implemented in the form of a computer program, and the above-mentioned intelligent controller can be implemented in the form of a computer device, and the computer program can be run on the computer device. The controller includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; the memory is used to store the computer program; the processor is used to execute the program stored in the memory to implement the steam generator water level control method based on digital twin as described in the above embodiment.

[0101] See also Figure 6 , Figure 6 is a schematic block diagram of a computer device provided in an embodiment of the present invention. The computer device may be a processor for executing a steam generator water level control method based on digital twin to realize control of various components.

[0102] See also Figure 6 The computer device 500 includes a processor 502 , a memory and a communication interface 505 connected via a communication bus 501 , wherein the memory may include a storage medium 503 and an internal memory 504 .

[0103] The storage medium 503 may store an operating system 5031 and a computer program 5032. When the computer program 5032 is executed, the processor 502 may execute a steam generator water level control method based on digital twins, wherein the storage medium 503 may be a volatile storage medium or a non-volatile storage medium.

[0104] The processor 502 is used to provide computing and control capabilities to support the operation of the entire computer device 500 .

[0105] The internal memory 504 provides an environment for the operation of the computer program 5032 in the storage medium 503. When the computer program 5032 is executed by the processor 502, the processor 502 can execute the steam generator water level control method based on digital twin.

[0106] The communication interface 505 is used for network communication, such as providing data information transmission, etc. Those skilled in the art will appreciate that Figure 6The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device 500 to which the solution of the present invention is applied. The specific computer device 500 may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0107] The processor 502 is used to run a computer program 5032 stored in the memory to implement the corresponding functions in the above-mentioned digital twin-based steam generator water level control method.

[0108] Those skilled in the art will understand that Figure 6 The embodiments of the computer device shown in the figure do not constitute a limitation on the specific composition of the computer device. In other embodiments, the computer device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. For example, in some embodiments, the computer device may only include a memory and a processor. In such embodiments, the structure and function of the memory and the processor are the same as those of the embodiment of the present invention. Figure 6 The embodiments shown are consistent and will not be described again here.

[0109] It should be understood that in the embodiment of the present invention, the processor 502 may be a central processing unit (CPU), and the processor 502 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0110] In another embodiment of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium may be a volatile or non-volatile computer-readable storage medium. The computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, the steps included in the steam generator water level control method based on digital twin are implemented.

[0111] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the above-described equipment, devices and units can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. Those of ordinary skill in the art can appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0112] In the several embodiments provided by the present invention, it should be understood that the disclosed equipment, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. Units with the same function may also be combined into one unit. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices or units, or may be an electrical, mechanical or other form of connection.

[0113] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present invention.

[0114] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0115] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a computer-readable storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned computer-readable storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a magnetic disk or an optical disk.

[0116] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A steam generator water level control method based on digital twin, the control method is applied to a steam generator water level control system, the intelligent controller of the steam generator water level control system is connected in communication with a sensor, a first flow regulator and a water level regulator provided in the steam generator, and the first flow regulator is connected in communication with a feedwater regulating valve; characterized in that: The control method comprises: The intelligent controller acquires the detection information obtained by the sensor in real time; The intelligent controller outputs the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount outputted correspondingly by the water level regulator; The intelligent controller analyzes the primary side detection data and the secondary side detection data in the detection information according to a preset real-time online heat balance model to obtain corresponding analysis results; the primary side detection data is the detection data corresponding to the primary steam supply loop side in the detection information, and the secondary side detection data is the detection data corresponding to the secondary steam supply loop side in the detection information; the analysis results include a calculated value of feed water flow and a calculated value of steam flow; The intelligent controller outputs the analysis result and the water supply flow adjustment amount to the first flow regulator; The first flow regulator correspondingly outputs a control instruction to the water supply regulating valve to regulate the water supply flow.

2. The steam generator water level control method based on digital twin according to claim 1 is characterized in that: Before the intelligent controller outputs the analysis result and the water supply flow adjustment amount to the first flow regulator, the intelligent controller further includes: The intelligent controller determines whether the reactor power in the detection information meets the preset operating conditions; If the operating condition is met, the intelligent controller executes the step of outputting the analysis result and the water supply flow adjustment amount to the first flow regulator; If the operating conditions are not met, the intelligent controller performs simulation calculation on the detection information according to a preset simulation model to obtain corresponding simulation calculation results; the simulation calculation results include a water level change trend and a water level change amplitude range; The intelligent controller outputs the simulation calculation result and the water supply flow adjustment amount to the first flow regulator, so that the first flow regulator correspondingly outputs a control instruction to the water supply regulating valve to adjust the water supply flow.

3. The steam generator water level control method based on digital twin according to claim 2 is characterized in that: The determining whether the reactor power in the detection information meets the preset operating condition includes: Determining whether the reactor power in the detection information is in a high power operating condition; Determining whether the reactor power in the detection information is in a stable operating condition; If the reactor power is in a high power condition and is in a stable operating condition, it is determined that the operating condition is met; If the reactor power is not in a high power condition or is not in a stable operating condition, it is determined that the operating condition is not met.

4. The steam generator water level control method based on digital twin according to claim 3 is characterized in that: The primary side detection data and the secondary side detection data in the detection information are analyzed according to the preset real-time online heat balance model to obtain corresponding analysis results, including: Constructing a first relationship between the heat exchange power of the steam generator and the steam flow rate and the feed water flow rate according to the real-time line heat balance model; A second relationship between steam flow and feed water flow is constructed based on the water supply and drainage balance relationship; Substitute known quantities in the primary-side detection data and the secondary-side detection data into the first relational expression and the second relational expression for analysis to obtain corresponding analysis results.

5. The steam generator water level control method based on digital twin according to claim 4 is characterized in that: The real-time line heat balance model includes Q=C p W×(T hot -T cold )and Wherein, Q is the heat exchange power of the steam generator, C p is the volume specific heat capacity, W is the primary side coolant flow rate, T hot and T cold are the inlet and outlet coolant temperatures of the primary side, Q2 is the heat exchange power between the primary side and the secondary side of the steam generator, A S is the heat transfer area, K is the total heat transfer coefficient, T sat is the saturation temperature.

6. The steam generator water level control method based on digital twin according to claim 5 is characterized in that: The calculation formula of the total heat transfer coefficient is: h p is the primary side heat transfer coefficient, U t is the thermal conductivity of the heat transfer tube, U f is the fouling heat transfer coefficient, h s is the secondary side heat transfer coefficient.

7. The steam generator water level control method based on digital twin according to claim 6 is characterized in that: The first relational expression is Q=W s ((1-x)H s +xH l )+W p H l -W f H f ; W s is the steam flow rate, W p is the secondary side sewage flow, W f is the water flow rate, H s Saturated steam enthalpy, H l Saturation enthalpy of water, H f Feed water enthalpy, x is the humidity percentage in the steam; The second relation is W f =W s +W p .

8. The steam generator water level control method based on digital twin according to claim 3 is characterized in that: The performing simulation calculation on the detection information according to the preset simulation model to obtain the corresponding simulation calculation result includes: Performing control volume division on the steam generator according to the division rule in the simulation model to obtain corresponding control volume division results; Calculating each control body in the control body division result according to the control equation in the simulation model to obtain the physical property parameters of each control body; The physical property parameters of each control body are solved and calculated according to the gas-liquid conservation equation in the simulation model to obtain corresponding simulation calculation results.

9. The steam generator water level control method based on digital twin according to claim 8, characterized in that: The control equations include: M is the mass of the control body; U is the energy of the control body; W is the mass flow rate of the flow channel; S is the flow cross section of the flow channel; ∑Q ST is the generalized source term; L is the flow channel length; Δp f is the friction pressure drop; Δp s is the local pressure drop; Δp g is the pressure drop at the gravity position; Δp a is the acceleration pressure drop; h is the specific enthalpy; the subscripts i and j are the control body numbers, k is the flow channel number between the control bodies, in is the flow into the control body, out is the flow out of the control body, and ex is the flow rate between the control body and the external interface.

10. The steam generator water level control method based on digital twin according to claim 9, characterized in that: The gas-liquid conservation equation is A is the flow cross section of the control body, v is the specific heat capacity of the control body, WL is the water level in the control body, and the subscript un is the lower area of ​​the control body with water level.

11. The steam generator water level control method based on digital twin according to any one of claims 4 to 10, characterized in that: The intelligent controller outputs the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount outputted correspondingly by the water level regulator, including: The intelligent controller outputs the actual measured water level in the detection information to the water level regulator; The water level regulator compares the actually measured water level with the set water level setting value, obtains the corresponding water supply flow adjustment amount and outputs it to the intelligent controller.

12. The steam generator water level control method based on digital twin according to any one of claims 4 to 10, characterized in that: The steam generator further includes a second flow regulator and a feedwater pump speed regulator, the second flow regulator is communicatively connected to the intelligent controller, the second flow regulator is communicatively connected to the feedwater pump speed regulator, and the control method further includes: The intelligent controller obtains the water supply main pipe pressure value and the steam main pipe pressure value in the detection information, performs difference calculation, and obtains the corresponding pressure difference measurement value; The intelligent controller inputs the pressure difference measurement value into the second flow regulator; The second flow regulator compares the pressure difference measurement value with the set pressure difference setting value, and outputs a control instruction to the water pump speed regulator to adjust the water pump speed according to the comparison result.

13. A steam generator water level control system based on digital twin, characterized in that: The steam generator water level control system is used to execute the steam generator water level control method based on digital twin according to any one of claims 1 to 12, and the steam generator water level control system includes a detection information acquisition unit configured in the intelligent controller, a first information output unit, an analysis result acquisition unit, a second information output unit, and a control instruction output unit configured in the first flow regulator; The detection information acquisition unit is used to acquire the detection information obtained by the sensor in real time; The first information output unit is used to output the actual measured water level in the detection information to the water level regulator to obtain the water supply flow adjustment amount outputted correspondingly by the water level regulator; The analysis result acquisition unit is used to analyze the primary side detection data and the secondary side detection data in the detection information according to a preset real-time online thermal balance model to obtain corresponding analysis results; The primary side detection data is the detection data corresponding to the primary steam supply circuit side in the detection information, and the secondary side detection data is the detection data corresponding to the secondary steam supply circuit side in the detection information; the analysis result includes the calculated value of feed water flow and the calculated value of steam flow; The second information output unit is used to output the analysis result and the water supply flow adjustment amount to the first flow regulator; The control instruction output unit is used to output a corresponding control instruction to the water supply regulating valve to adjust the water supply flow rate.

14. A steam generator water level control device based on digital twin, characterized in that: The steam generator water level control device includes an intelligent controller, a sensor, a first flow regulator, a water level regulator, a feed water regulating valve, a second flow regulator and a feed water pump speed regulator; One end of the water supply main pipe is connected to the output port of the first water supply pump, and the other end is connected to the water supply input end of at least one steam generator; the water supply regulating valve is arranged in series on one side of the water supply main pipe close to the water supply input end; each steam generator is connected to the steam turbine through the steam main pipe; The sensors include a differential pressure sensor, a steam pressure sensor, a main pipe pressure sensor, a water supply sensor, a water supply flow sensor, a water outlet sensor and a steam flow sensor; The two detection ends of the differential pressure sensor are respectively connected to the two pressure detection ports of one of the steam generators, and the signal output end of the differential pressure sensor is connected to the intelligent controller; the detection end of the steam pressure sensor is connected to the steam main pipe, and the signal output end of the steam pressure sensor is connected to the intelligent controller; the detection end of the main pipe pressure sensor is connected to the water supply main pipe, and the signal output end of the main pipe pressure sensor is connected to the intelligent controller; The detection end of the water supply sensor is connected to the water supply pipe of the steam generator, and the signal output end of the water supply sensor is connected to the intelligent controller; the detection end of the water outlet sensor is connected to the drain pipe of the steam generator, and the signal output end of the water outlet sensor is connected to the intelligent controller; the detection end of the steam flow sensor is connected to the steam main pipe, and the signal output end of the steam flow sensor is connected to the intelligent controller; the detection end of the water supply flow sensor is connected to the water supply main pipe and the connection point is located upstream of the water supply regulating valve, and the signal output end of the water supply flow sensor is connected to the intelligent controller; The intelligent controller is in communication connection with each sensor, the first flow regulator, the water level regulator and the second flow regulator; the first flow regulator is in communication connection with the water supply regulating valve; the second flow regulator is in communication connection with the water supply pump speed regulator; The intelligent controller includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory, used to store computer programs; The processor is used to implement the steam generator water level control method based on digital twin as described in any one of claims 1 to 12 when executing the program stored in the memory.

15. 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 steam generator water level control method based on digital twin are implemented as described in any one of claims 1 to 12.

Images