Water level prediction method, device and computer equipment of steam generator

Abstract

The application relates to a water level prediction method and device of a steam generator and a computer device, which comprises the following steps: obtaining equipment parameters and operation parameters of the steam generator; inputting the equipment parameters and the operation parameters into a steam generator model for estimation to obtain steam pressure values and mass flow values; and determining a water level prediction value of the steam generator according to the steam pressure values and the mass flow values. Since the steam generator model is constructed based on the structure and working principle of the steam generator, the model can reflect the operation of the real steam generator, so that the accuracy of water level prediction can be improved when the steam generator model is used for water level prediction, and the real-time water level can be accurately predicted according to the equipment parameters and the operation parameters at the current moment, so that the efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of nuclear power plant operation optimization control, and in particular to a method, apparatus and computer equipment for predicting the water level of a steam generator. Background Technology

[0002] The inverted U-shaped vertical natural circulation steam generator in a nuclear power plant is the key link between the primary and secondary loops of a pressurized water reactor nuclear power plant. According to international statistics on pressurized water reactor nuclear power plant operation accidents, about one-quarter of the unplanned shutdowns of pressurized water reactor nuclear power plants are caused by improper control of the steam generator water level. Therefore, whether the water level of the steam generator can be accurately controlled directly affects the safety of the steam generator operation and the economic efficiency of the unit.

[0003] Currently, the main method for controlling the water level of a steam generator is to predict the inlet water control amount in advance based on the size parameters and steam outlet parameters of the steam generator, and then control the water level of the steam generator according to the inlet water control amount to keep the water level of the steam generator at a predetermined level.

[0004] However, the above-mentioned methods for predicting water levels have the problem of inaccurate predictions. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, apparatus, and computer equipment for predicting the water level of a steam generator that can improve the accuracy of prediction, in order to address the above-mentioned technical problems.

[0006] In a first aspect, this application provides a method for predicting the water level of a steam generator, the method comprising:

[0007] Obtain the equipment parameters and operating parameters of the steam generator;

[0008] The equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values.

[0009] The predicted water level of the steam generator is determined based on the steam pressure and mass flow rate values.

[0010] In one embodiment, the steam generator model includes a loop model and a loop resistance model. Equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values, including:

[0011] The preset working fluid mass flow rate, equipment parameters, and operating parameters in the descending channel are input into the loop model for estimation to obtain the first estimation result. The first estimation result includes at least one of the following: flash steam mass flow rate in the feedwater chamber of the descending channel, feedwater mass flow rate, recirculated water mass flow rate, working fluid velocity in the preheating section of the ascending channel, gas and liquid working fluid velocities in the boiling section of the ascending channel, and working fluid cavitation rate in the boiling section of the ascending channel.

[0012] The operating parameters and the first estimation result are input into the loop resistance model for estimation to obtain the second estimation result. The second estimation result includes at least one of the following: pressure of the working medium in the feedwater chamber of the descending channel, pressure of the feedwater chamber outlet of the descending channel, pressure of the working medium in the annular gap of the descending channel, pressure of the annular gap outlet of the descending channel, pressure of the working medium in the preheating section of the ascending channel, pressure of the working medium in the boiling section of the ascending channel, pressure of the support orifice plate of the ascending channel, and pressure of the working medium at the inlet and outlet of the steam-water separator.

[0013] The steam pressure value is determined based on the operating parameters and the second estimation result.

[0014] In one embodiment, the loop model includes a downflow channel model, a water level control system model, an upflow channel model, and a steam-water separator model. Preset downflow channel working fluid mass flow rate, equipment parameters, and operating parameters are input into the loop model for estimation to obtain a first estimation result, including:

[0015] The preset mass flow rate of the working fluid in the descending channel, equipment parameters, and operating parameters are input into the descending channel model for estimation to obtain the mass flow rate of flash steam in the feedwater chamber of the descending channel.

[0016] The mass flow rate of flash steam in the feedwater chamber of the descending channel is input into the water level control system model for estimation to obtain the feedwater mass flow rate;

[0017] The preset working fluid mass flow rate, feed water mass flow rate, equipment parameters and operating parameters in the descending channel are input into the ascending channel model for estimation, so as to obtain the working fluid velocity in the preheating section of the ascending channel, the gas phase and liquid phase working fluid velocities in the boiling section of the ascending channel, and the working fluid cavitation rate in the boiling section of the ascending channel.

[0018] Determine the recirculated water mass flow rate based on the equipment parameters corresponding to the steam-water separator model.

[0019] In one embodiment, determining the predicted water level of the steam generator based on the steam pressure and mass flow rates includes:

[0020] Based on the distance between the steam pressure value and the target steam pressure value, as well as the preset distance threshold, determine whether the steam pressure value meets the preset conditions;

[0021] When the steam pressure value meets the preset conditions, the mass flow rate value is input into the preset water level prediction model to predict the water level and obtain the predicted water level value of the steam generator.

[0022] In one embodiment, determining whether the steam pressure value meets a preset condition based on the distance between the steam pressure value and the target steam pressure value, and a preset distance threshold, includes:

[0023] If the distance is less than the preset distance threshold, the steam pressure value is determined to meet the preset conditions; if the distance is not less than the preset distance threshold, the steam pressure value is determined to not meet the preset conditions.

[0024] In one embodiment, the method further includes:

[0025] If the steam pressure value does not meet the preset conditions, the mass flow rate value is corrected based on the steam pressure value to obtain the corrected mass flow rate value.

[0026] The corrected mass flow rate value is input into the steam generator model for estimation to obtain a new steam pressure value.

[0027] Based on the new steam pressure value and the corrected mass flow rate value, return to the step of determining the predicted water level of the steam generator based on the steam pressure value and the mass flow rate value.

[0028] Secondly, this application also provides a water level prediction device for a steam generator, the device comprising:

[0029] The acquisition module is used to acquire the equipment parameters and operating parameters of the steam generator;

[0030] The prediction module is used to input equipment parameters and operating parameters into the steam generator model for estimation, and obtain steam pressure and mass flow rate values;

[0031] The determination module is used to determine the predicted water level of the steam generator based on the steam pressure and mass flow rate values.

[0032] Thirdly, this application also provides a computer device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0033] Obtain the equipment parameters and operating parameters of the steam generator;

[0034] The equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values.

[0035] The predicted water level of the steam generator is determined based on the steam pressure and mass flow rate values.

[0036] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0037] Obtain the equipment parameters and operating parameters of the steam generator;

[0038] The equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values.

[0039] The predicted water level of the steam generator is determined based on the steam pressure and mass flow rate values.

[0040] Fifthly, this application also provides a computer program product, which includes a computer program that, when executed by a processor, performs the following steps:

[0041] Obtain the equipment parameters and operating parameters of the steam generator;

[0042] The equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values.

[0043] The predicted water level of the steam generator is determined based on the steam pressure and mass flow rate values.

[0044] The aforementioned method, apparatus, and computer equipment for predicting water level in a steam generator involve acquiring the equipment and operating parameters of the steam generator, inputting these parameters into a steam generator model for estimation to obtain steam pressure and mass flow rates, and then determining the predicted water level based on these values. Since the steam generator model is constructed based on its structure and operating principle, it accurately reflects the actual operation of the steam generator. Therefore, using this model for water level prediction improves accuracy and avoids false water level predictions caused by the coupling of multiple factors in traditional methods. Furthermore, this method only requires the equipment parameters and current operating parameters to accurately predict the real-time water level, thus improving efficiency. Attached Figure Description

[0045] Figure 1 This is an internal structural diagram of a computer device in one embodiment;

[0046] Figure 2 This is a flowchart illustrating a method for predicting the water level of a steam generator in one embodiment;

[0047] Figure 3 This is a schematic diagram of the structure of various parts of a steam generator in one embodiment;

[0048] Figure 4 This is a flowchart illustrating the water level prediction method for a steam generator in another embodiment;

[0049] Figure 5 This is a flowchart illustrating the water level prediction method for a steam generator in another embodiment;

[0050] Figure 6 This is a flowchart illustrating the water level prediction method for a steam generator in another embodiment;

[0051] Figure 7 A comparison chart of the predicted water level of the steam generator and the measured water level of the steam generator;

[0052] Figure 8 This is a flowchart illustrating the water level prediction method for a steam generator in another embodiment;

[0053] Figure 9 This is a flowchart illustrating the water level prediction method for a steam generator in another embodiment;

[0054] Figure 10 This is a structural block diagram of a water level prediction device for a steam generator in one embodiment. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0056] The inverted U-shaped vertical natural circulation steam generator in a nuclear power plant is the key link between the primary and secondary loops of a pressurized water reactor (PWR) nuclear power plant. According to international statistics on PWR nuclear power plant operational accidents, approximately one-quarter of unplanned shutdowns of PWR nuclear power plants are caused by improper steam generator water level control. Therefore, the ability to accurately control the steam generator water level directly affects the safety of steam generator operation and the economic efficiency of the unit. Currently, the main method for controlling the steam generator water level is to predict the inlet water control quantity in advance based on the steam generator's size parameters and outlet parameters, and then control the steam generator water level according to the inlet water control quantity to maintain it at a predetermined level. However, the above method of water level prediction has the problem of inaccurate prediction.

[0057] This application provides a method for predicting the water level of a steam generator, which aims to solve the above-mentioned technical problems. The following embodiments will specifically illustrate the method for predicting the water level of a steam generator described in this application.

[0058] The water level prediction method for steam generators provided in this application embodiment can be applied to, for example... Figure 1The computer device shown can be a server or a terminal. It includes a processor, memory, input / output interfaces, a communication interface, a display unit, and input devices. The processor, memory, and input / output interfaces are connected via a system bus, and the communication interface, display unit, and input devices are also connected to the system bus via the input / output interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interfaces are used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a method for predicting the water level of a steam generator. The display unit is used to form a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0059] Those skilled in the art will understand that Figure 1 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0060] In one embodiment, such as Figure 2 As shown, a method for predicting the water level of a steam generator is provided, which can be applied to... Figure 1 Taking a computer device as an example, the explanation includes the following steps:

[0061] S101, obtain the equipment parameters and operating parameters of the steam generator.

[0062] Among them, the equipment parameters are the parameters of the equipment structure of the steam generator, including the cross-sectional area A of the feedwater chamber in the downflow channel. dc1 , the flow area A of the descending channel annular gap dc2 The upward channel circulation area A rc The cross-sectional area A of the steam-water separator sp , Height H of the descending channel annulus dc2 The height H from the bottom of the steam-water separator to the rotary vanesp1 The height H of the vapor separator vane to the top sp2 d, diameter of the water supply chamber in the descending channel dc1 , Outer radius R of the descending channel annulus dc2 , inner radius r of the descending channel annular gap dc2 Equivalent diameter d of the ascending channel e,rc Parameters, etc. Operating parameters are the operating data of the steam generator at a certain moment, including: the measured value T of the primary loop coolant inlet temperature. 1,in Measured value of primary coolant outlet temperature T 1,out Measured value of primary coolant mass flow rate D1, and measured value of feedwater temperature T. fw Measured value of main steam pressure p ms .

[0063] In this embodiment, the computer device can first establish a wired or wireless connection with the distributed control system (DCS) of the nuclear power plant. After successful connection, it sends a command to the DCS to obtain parameters and receives the equipment parameters and current operating parameters returned by the DCS. Optionally, the computer device can obtain the equipment parameters from the equipment manuals and instructions related to the steam generator.

[0064] S102, input the equipment parameters and operating parameters into the steam generator model for estimation to obtain the steam pressure value and mass flow rate value.

[0065] The steam generator model is a mechanistic simulation model based on the steam generator. The steam generator model includes a loop model, a loop resistance model, and a preset water level prediction model. The loop model includes a downflow channel model, a water level control system model, an upflow channel model, and a steam-water separator model. The water level control system model includes a water level controller model, a flow controller model, and a main water regulating valve model. The upflow channel model includes an upflow channel preheating section model, an upflow channel boiling section model, and an upflow channel boiling section working fluid model. The loop resistance models include the downflow channel feedwater chamber resistance model, the downflow channel feedwater chamber outlet resistance model, the downflow channel annular gap resistance model, the downflow channel annular gap outlet resistance model, the upflow channel preheating section flow resistance model, the upflow channel boiling section flow resistance model, the upflow channel support orifice plate resistance model, and the steam-water separator resistance model. The steam pressure value is the steam-water separator outlet pressure. The mass flow rate value includes at least one of the following: flash steam mass flow rate in the feedwater chamber of the descending channel, feedwater mass flow rate, recirculated water mass flow rate, working fluid velocity in the preheating section of the ascending channel, gaseous working fluid velocity in the boiling section of the ascending channel, liquid working fluid velocity in the boiling section of the ascending channel, and working fluid cavitation rate in the boiling section of the ascending channel.

[0066] In this embodiment of the application, the computer device pre-constructs a mechanism simulation model corresponding to each part of the steam generator based on the structure and working principle of each part, such as... Figure 3 The diagram shows the structure of each part of the steam generator. Based on the structure of each part, including the feedwater inlet, the feedwater chamber of the downflow channel, the annular gap of the downflow channel, the primary coolant inlet, the primary coolant outlet, the preheating section of the rising channel, the boiling section of the rising channel, the steam-water separator, and the main steam outlet, as well as the corresponding working principle, a steam generator model is constructed using mathematical and physical models. After obtaining the equipment parameters and operating parameters, the computer can input these parameters into the steam generator model. Through the coupling between the various models, the physical processes of each part and the corresponding energy and mass balance are simulated to obtain the current steam pressure and mass flow rate of the steam generator.

[0067] S103, determine the predicted water level of the steam generator based on the steam pressure and mass flow rate values.

[0068] Among them, the water level prediction value is the real-time prediction value of the water level of the steam generator.

[0069] In this embodiment, the computer device pre-constructs a water level prediction model for the steam generator based on the structure and working principle of each part of the steam generator, thus obtaining a preset water level prediction model. After obtaining the steam pressure and mass flow rates based on the above steps, the model algorithm can be optimized by combining the steam pressure and mass flow rates to predict the water level of the steam generator. For example, first, it is determined whether the steam pressure and mass flow rates meet the prediction conditions. If the steam pressure and mass flow rates meet the prediction conditions, they are input into the preset water level prediction model for prediction to obtain the predicted water level of the steam generator. If the steam pressure and mass flow rates do not meet the prediction conditions, the model algorithm is optimized to update the steam pressure and mass flow rates until the updated steam pressure and mass flow rates meet the prediction conditions. Then, the steam pressure and mass flow rates are input into the preset water level prediction model for prediction to obtain the predicted water level of the steam generator. Furthermore, it can be determined whether the steam pressure and mass flow rates meet the prediction conditions by judging whether they meet the target steam pressure and target mass flow rates. Optionally, it can be further determined whether the steam pressure value meets the prediction conditions. If the steam pressure value meets the prediction conditions, the steam pressure value and mass flow rate value are input into a preset water level prediction model for prediction to obtain the predicted water level value of the steam generator. If the steam pressure value does not meet the prediction conditions, the steam pressure value and mass flow rate value are updated again through model algorithm optimization until the updated steam pressure value and mass flow rate value meet the prediction conditions. Then, the steam pressure value and mass flow rate value are input into the preset water level prediction model for prediction to obtain the predicted water level value of the steam generator. Further, it can be determined whether the steam pressure value meets the target steam pressure value to determine whether the steam pressure value and mass flow rate value meet the prediction conditions. Optionally, the steam pressure value and mass flow rate value can also be directly input into the preset water level prediction model for prediction to obtain the predicted water level value of the steam generator.

[0070] In this embodiment, the equipment parameters and operating parameters of the steam generator are obtained, and then input into the steam generator model for estimation to obtain steam pressure and mass flow rate values. Based on these values, the predicted water level of the steam generator is determined. Since the steam generator model is built based on the structure and working principle of the steam generator, it can reflect the actual operation of the steam generator. Therefore, using this model for water level prediction improves the accuracy of prediction and avoids the false water level results caused by the coupling of multiple factors in traditional methods. Furthermore, using this method, the real-time water level can be accurately predicted based solely on the equipment parameters and the current operating parameters, thus improving efficiency.

[0071] In one embodiment, the steam generator model in the above embodiment includes a loop model and a loop resistance model. Based on this, a specific implementation method for obtaining steam pressure and mass flow rate values ​​is also provided, such as... Figure 4 As shown, step S102 above, "inputting equipment parameters and operating parameters into the steam generator model for estimation to obtain steam pressure and mass flow rate values," includes:

[0072] S201, the preset descent channel working fluid mass flow rate, equipment parameters and operating parameters are input into the loop model for estimation to obtain the first estimation result.

[0073] The loop model includes a descending channel model, a water level control system model, an ascending channel model, and a steam-water separator model. The water level control system model includes a water level controller model, a flow controller model, and a main water regulating valve model. The ascending channel model includes an ascending channel preheating section model, an ascending channel boiling section model, and an ascending channel boiling section working fluid model. The descending channel working fluid mass flow rate is preset as a parameter for adjusting and optimizing the model; this parameter can be any value or a historical value. The first estimation result includes at least one of the following: descending channel feedwater chamber flash steam mass flow rate, feedwater mass flow rate, recirculated water mass flow rate, ascending channel preheating section working fluid velocity, ascending channel boiling section gas phase working fluid velocity, ascending channel boiling section liquid phase working fluid velocity, and ascending channel boiling section working fluid cavitation rate.

[0074] Furthermore, such as Figure 5 As shown, step S201 above, "inputting the preset descent channel working fluid mass flow rate, equipment parameters, and operating parameters into the loop model for estimation to obtain the first estimation result," includes:

[0075] S2010, input the operating parameters into the descending channel model for estimation, and obtain the mass flow rate of flash steam in the descending channel feedwater chamber.

[0076] Specifically, the descending channel model is the descending channel feedwater chamber flash evaporation model.

[0077] In this embodiment of the application, after the computer device obtains the operating parameters, it can convert the measured value p of the main steam pressure in the operating parameters into... ms The input is fed into the flash steam model of the descending feedwater chamber for estimation, and the mass flow rate D of the flash steam in the descending feedwater chamber is obtained. fla Specifically, the flash evaporation model of the feedwater chamber in the descending channel can be represented by the following relationship (1):

[0078]

[0079] Among them, D fla This refers to the mass flow rate of flash steam in the feedwater chamber of the descending channel, in kg / s; Mdc1 This refers to the mass of the working fluid in the feedwater chamber of the descending channel, expressed in kg / h. dc1 It is the specific enthalpy of the working fluid in the feedwater chamber of the descending channel, in kJ / kg; h dc1,l The measured value of the main steam pressure p ms The specific enthalpy of saturated water, in kJ / kg; h dc1,g The measured value of the main steam pressure p ms The specific enthalpy of the corresponding saturated dry steam, in kJ / kg; Δt is the calculation step size, in seconds.

[0080] S2011, the mass flow rate of flash steam in the feedwater chamber of the descending channel is input into the water level control system model for estimation to obtain the feedwater mass flow rate.

[0081] The water level control system model includes a water level controller model, a flow controller model, and a main water regulating valve model.

[0082] In this embodiment of the application, the computer device can measure the mass flow rate D of the flash steam in the feedwater chamber of the descending channel. fla The water level is input into the water level control system model for estimation to obtain the water supply mass flow rate D. fw Specifically, the water level control system model can be represented by the following relationships (2) to (4):

[0083]

[0084]

[0085]

[0086] Among them, relation (2) is the water level controller model, relation (3) is the flow controller model, and relation (4) is the main water regulating valve model. sp This is the setpoint for the steam feedwater flow difference, in kg / s; K p1 This is the proportional coefficient of the water level controller, measured in kg / s / m; τ i1 τ is the integral time constant of the water level controller, measured in seconds (s). d1 It is the differential time constant of the water level controller, in seconds (s); L sp This is the water level setpoint, in meters (m); L t-1 This is the predicted water level of the steam generator obtained from the previous calculation, in meters (m); τ lv C is the time constant of the water level filter, measured in seconds. fwv It refers to the opening degree of the main water supply regulating valve; K p2 This is the proportional gain of the flow controller, measured in %·s / kg; τ i2 τ is the integral time constant of the flow controller, in seconds; msD is the time constant of the main steam filter, in seconds. ss K is the mass flow rate of steam at the outlet of the steam-water separator, in kg / s. fwv This is the proportional coefficient of the main water supply regulating valve, in units of kg / s / %; τ fwv D is the time constant of the main water supply regulating valve, in seconds. fw2 It is the working fluid mass flow rate of the main feedwater bypass regulating valve, in kg / s;

[0087] S2012, the preset working fluid mass flow rate, feed water mass flow rate, equipment parameters and operating parameters of the descending channel are input into the ascending channel model for estimation, so as to obtain the working fluid velocity in the preheating section of the ascending channel, the gas phase and liquid phase working fluid velocities in the boiling section of the ascending channel, and the working fluid cavitation rate in the boiling section of the ascending channel.

[0088] The rising channel model includes the rising channel preheating section model, the rising channel boiling section model, and the rising channel boiling section working fluid model.

[0089] In this embodiment of the application, the computer device obtains the water supply mass flow rate D. fw Then, the preset descent channel working fluid mass flow rate D can be set. dc Water supply mass flow rate D fw The equipment parameters and operating parameters are input into the rising channel model for estimation to obtain the working fluid flow velocity u in the preheating section of the rising channel. rc1 The gaseous working fluid flow rate u in the boiling section of the rising channel rc2,g The liquid working fluid flow rate u in the boiling section of the rising channel rc2,l α, the working fluid cavitation rate in the boiling section of the rising channel rc2 Specifically, the model of the preheating section of the ascending channel can be represented by the following relationships (5) to (8):

[0090]

[0091]

[0092]

[0093]

[0094] Where z is the vertical distance from the control body to the end plate, in meters; ρ rc1 It is the density of the working fluid in the preheating section of the rising channel, kg / m³ 3 ;u rc1 This refers to the working fluid velocity in the preheating section of the rising channel, expressed in m / s or h. rc1 It is the specific enthalpy of the working fluid in the preheating section of the ascending channel, in kJ / kg; p rc1 Q is the working fluid pressure in the preheating section of the rising channel, in Pa; Q is the heat absorbed per unit volume of the secondary loop working fluid, in kW / m³.3 The measured value T of the primary coolant inlet temperature can be obtained from the operating data. 1，in Measured value of primary coolant outlet temperature T 1,out A was calculated from the measured mass flow rate of the primary coolant. rc It refers to the flow area of ​​the ascending channel, in m2; h fw It is the feedwater specific enthalpy, which is the measured feedwater temperature T in the operational data. fw Sure;

[0095] Specifically, the boiling section model of the rising channel can be represented by the following relationships (9) to (12):

[0096]

[0097]

[0098]

[0099]

[0100] Where, α rc2 It is the cavitation rate of the working fluid in the boiling section of the rising channel, dimensionless; ρ rc2,g This refers to the density of the gaseous working fluid in the boiling section of the rising channel, in kg / m³; ρ rc2,l This refers to the density of the liquid working fluid in the boiling section of the rising channel, in kg / m³. 3 ;u rc2,g This refers to the gaseous working fluid velocity in the boiling section of the rising channel, expressed in m / s; u rc2,l This refers to the flow rate of the liquid working fluid in the boiling section of the rising channel, expressed in m / s or h. rc2,g It is the specific enthalpy of the gaseous working fluid in the boiling section of the rising channel, in kJ / kg; h rc2,l It is the specific enthalpy of the liquid working fluid in the boiling section of the rising channel, in kJ / kg; p rc2 Γ is the working fluid pressure in the boiling section of the rising channel, in Pa; Γ is the mass exchange rate of the gas and liquid phases per unit volume, in kg / s / m³. 3 E represents the energy exchange rate per unit volume of gaseous and liquid working fluid, expressed in kW / m³. 3 .

[0101] Specifically, the working fluid model for the boiling section of the rising channel can be represented by the following relationship (13):

[0102]

[0103] Where, β rc2 C0 is the volumetric gas flow rate of the working fluid in the boiling section of the rising channel, dimensionless; C0 is the radial non-uniformity coefficient, dimensionless; u rc2,gjU is the gaseous drift velocity of the working fluid in the boiling section of the rising channel, in m / s. rc2 It is the apparent velocity of the working fluid in the boiling section of the rising channel, in m / s.

[0104] β rc2 It can be calculated using the following relation (14); C0 can be calculated using the following relation (15); u rc2 ,gj can be calculated using the following relation (16); U rc2 It can be calculated using the following relationship (17). Where σrc2 is the surface tension of the working fluid gas-liquid in the boiling section of the rising channel, N / m; g is the gravitational acceleration, m / s2.

[0105]

[0106]

[0107]

[0108] U rc2 =α rc2 u rc2,g +(1-α rc2 )u rc2,l (17);

[0109] S2013, determine the recirculated water mass flow rate based on the equipment parameters corresponding to the steam-water separator model.

[0110] In this embodiment, the computer device can use the equipment parameters corresponding to the steam-water separator model obtained in the above steps, and then calculate the recirculated water mass flow rate D based on the water separator model. rw Specifically, the boiling section model of the rising channel can be represented by the following relationships (18) to (19):

[0111] D ss =x sp η sp ρ sp,m A sp U sp (18);

[0112] D rw =(1-x sp η sp )ρ sp,m A sp U sp (19);

[0113] Among them, D rw This is the recirculated water mass flow rate, in kg / s; D ss This is the mass flow rate of the separated steam, in kg / s; ηsp It refers to the separation efficiency of the steam-water separator; U sp This is the apparent velocity of the working fluid in the gas-water separator, in m / s; x sp ρ is the working fluid gas content in a gas-water separator, dimensionless; sp,m This refers to the working fluid mixing density in a gas-water separator, expressed in kg / s; x sp It can be calculated using the following relation (20); ρ sp,m It can be calculated using the following relation (21);

[0114]

[0115]

[0116] Where, β sp ρ is the volumetric gas flow rate of the working fluid in the gas-water separator, dimensionless; sp,g This refers to the density of the gaseous working fluid in the gas-water separator, in kg / m³. 3 ;ρ sp,l This refers to the density of the liquid working fluid in the gas-water separator, in kg / m³. 3 .

[0117] S202, input the operating parameters and the first estimation result into the loop resistance model for estimation, and obtain the second estimation result.

[0118] The loop resistance models include the following: the resistance model for the feedwater chamber in the descending channel; the resistance model for the feedwater chamber outlet in the descending channel; the resistance model for the annular gap in the descending channel; the resistance model for the annular gap outlet in the descending channel; the flow resistance model for the preheating section in the ascending channel; the flow resistance model for the boiling section in the ascending channel; the resistance model for the orifice plate support in the ascending channel; and the resistance model for the steam-water separator. The second estimation result includes at least one of the following: the pressure of the working medium in the feedwater chamber in the descending channel; the pressure of the feedwater chamber outlet in the descending channel; the pressure of the working medium in the annular gap in the descending channel; the pressure of the annular gap outlet in the descending channel; the pressure of the working medium in the preheating section of the ascending channel; the pressure of the working medium in the boiling section of the ascending channel; the pressure of the orifice plate support in the ascending channel; and the pressure of the working medium at the inlet and outlet of the steam-water separator.

[0119] In this embodiment of the application, the computer device will obtain the measured value p of the main steam pressure from the operating parameters. ms The working fluid velocity u in the rising channel preheating section of the mass flow rate value rc1 The gaseous working fluid flow rate u in the boiling section of the rising channel rc2,g The liquid working fluid flow rate u in the boiling section of the rising channel rc2,l α, the working fluid cavitation rate in the boiling section of the rising channel rc2 The pressure p of the working fluid in the feedwater chamber of the descending channel is estimated by inputting it into the loop resistance model. dc1 , Downward channel water supply chamber outlet pressure p dc1,outThe pressure p of the working fluid in the annular gap of the descending channel dc2 , descending channel annular gap outlet pressure p dc2,out The working fluid pressure p in the preheating section of the rising channel rc1 The working fluid pressure p in the boiling section of the rising channel rc2 The pressure p of the support plate in the rising channel op The working fluid pressure at the inlet and outlet of the steam-water separator, p sp .

[0120] Specifically, the resistance model of the feedwater chamber in the descending channel can be expressed by the following relationships (22) to (24):

[0121]

[0122]

[0123]

[0124] p dc1 This is the pressure of the working fluid in the feedwater chamber of the downflow channel, in Pa; ρ dc This refers to the density of the working fluid in the descending channel, in kg / m³; u dc1 f is the working fluid velocity in the feedwater chamber of the descending channel, in m / s. dc1 It is the frictional resistance coefficient of the working medium in the feedwater chamber of the descending channel, dimensionless; d dc1 A is the diameter of the water supply chamber in the descending channel, in meters (m); g is the acceleration due to gravity, in meters per second (m / s²); A dc1 It is the flow area of ​​the water supply chamber in the descending channel; μ dc It is the dynamic viscosity of the working fluid in the descending channel, in Pa·s;

[0125] Specifically, the outlet resistance model of the feedwater chamber in the descending channel can be expressed by the following relationships (25) to (26):

[0126]

[0127]

[0128] p dc1,out This is the outlet pressure of the feedwater chamber in the descending channel, in Pa; Δp dc1,out This is the change in outlet pressure of the feedwater chamber in the descending channel, in Pa; A dc2 It is the flow area of ​​the annular gap in the descending channel, in meters. 2 ;u dc2 It is the working fluid velocity in the annular gap of the descending channel, in m / s.

[0129] Specifically, the descending channel annular resistance model can be expressed by the following relationship (27):

[0130]

[0131] p dc2 It is the pressure of the working fluid in the annular gap of the descending channel, in Pa; Δp dc2 It is the pressure difference between the inlet and outlet of the annular gap in the descending channel, Pa; H dc2 R is the height of the annular gap in the descent channel, in meters (m). dc2 It is the outer radius of the annular gap in the descent channel, in meters (m); r dc2 It is the inner radius of the annular gap in the descent channel, in meters;

[0132] Specifically, the exit resistance model of the descending channel annulus can be expressed by the following relationship (28):

[0133]

[0134] Δpdc2,out is the change in pressure at the outlet of the annular gap in the descending channel, in Pa; A rc It refers to the flow area of ​​the ascending channel, in meters (m). 2 ;

[0135] Specifically, the flow resistance model of the preheating section of the rising channel can be expressed by the following relationships (29) to (30):

[0136]

[0137]

[0138] p rc1 This is the working fluid pressure in the preheating section of the rising channel, in Pa; f rc1 It is the friction coefficient of the working fluid in the preheating section of the rising channel, dimensionless; d e,rc It is the equivalent diameter of the ascending channel, in meters (m); μ rc1 This is the dynamic viscosity of the working fluid in the preheating section of the rising channel, in Pa·s;

[0139] Specifically, the flow resistance model of the boiling section in the rising channel can be expressed by the following relationships (31) to (37):

[0140]

[0141] ρ rc2,m =α rc2 ρ rc2,g +(1-α rc2 )ρ rc2,l (32);

[0142]

[0143]

[0144]

[0145]

[0146]

[0147] p rc2 This is the working fluid pressure in the boiling section of the rising channel, in kPa; ρ rc2,m It is the working fluid mixing density in the boiling section of the rising channel, in kg / m³. 3 ;u rc2,m It is the mixing velocity of the working fluid in the boiling section of the rising channel, in m / s; Φ rc22 It is the total liquid-phase frictional pressure drop factor in the boiling section of the rising channel, dimensionless; f rc2 It is the coefficient of frictional resistance of the working fluid in the boiling section of the rising channel, dimensionless; x rc2 It is the working fluid gas content in the boiling section of the rising channel, dimensionless; μ m This is the viscosity of the working fluid in the boiling section of the rising channel, expressed in Pa·s; μ. g This is the dynamic viscosity of the gaseous working fluid in the boiling section of the rising channel, in Pa·s; μ. l It is the dynamic viscosity of the liquid working fluid in the boiling section of the rising channel, in Pa·s;

[0148] Specifically, the resistance model of the support orifice plate in the ascending channel can be expressed by the following relationships (38) to (39):

[0149]

[0150]

[0151] In the formula, p op This is the pressure of the support orifice plate in the rising channel, in kPa; Δp op This is the pressure drop across the support orifice plate in the ascending channel, in kPa; C 1,op Δδ is the inertial drag coefficient of the support orifice plate in the ascending channel, dimensionless; Δδ is the thickness of the support orifice plate in the ascending channel, in meters (m); d e,op It is the equivalent diameter of the support orifice plate for the rising channel, in meters (m); φ op It is the porosity of the support plate of the rising channel, which is dimensionless;

[0152] Specifically, the resistance model of the steam-water separator can be expressed by the following relationship (40):

[0153] -Δp sp =0.5ζ sp ρ sp1 u sp 2 +ρ sp1 gH sp1 +ρsp2 gH sp2 (40);

[0154] In the formula, p sp Δp is the inlet and outlet working fluid pressure of the steam-water separator, in kPa; sp This is the pressure difference between the inlet and outlet working fluids of the steam-water separator, in kPa; ζ sp It is the shape drag coefficient of the steam generator, dimensionless; u sp ρ is the working fluid velocity inside the gas-water separator, measured in m / s. sp1 ρ is the density of the working fluid in the gas-water separator before separation, expressed in kg / m³. sp2 H is the density of the working fluid after separation in the gas-water separator, expressed in kg / m³. sp1 H is the height from the bottom of the steam-water separator to the rotary vane, in meters (m). sp2 It is the height of the vapor separator blades to the top, in meters;

[0155] S203, determine the steam pressure value based on operating parameters and the second estimation result.

[0156] Wherein, the steam pressure value is the outlet pressure p of the steam-water separator. sp,out .

[0157] In this embodiment of the application, the computer device is based on the measured value p of the main steam pressure in the operating parameters. ms The sum of the second estimate obtained from the above steps yields the steam pressure value, i.e., the steam-water separator outlet pressure psp,out, which can be expressed by the following relationship (40):

[0158] p sp,out =p ms +Δp dc1 +Δp dc1,out +Δp dc2 +Δp dc2,out +Δp rc1 +Δp rc2 +Δp op +Δp sp (40);

[0159] The steam generator water level prediction method provided in this application provides a method for quantitatively calculating the mass flow rate of flash steam in the feedwater chamber of the descending channel through a descending channel model. It describes the dynamic characteristics of the water level control system when the steam generator water level changes through a water level control system model, providing conditions for closed-loop estimation and short-term forecasting of the steam generator water level. Through the rising channel model and the steam-water separator model, it provides a method for quantitatively calculating the recirculated water mass flow rate, the working fluid velocity in the preheating section of the rising channel, the gas and liquid phase working fluid velocities in the boiling section of the rising channel, and the working fluid cavitation rate in the boiling section of the rising channel, solving the problem of unmeasurable process variables. Through the loop resistance model, it provides a method for quantitatively calculating the flow resistance and pressure of the working fluid in the secondary loop, solving the problem of unmeasurable working fluid pressure at various locations in the secondary loop. The interaction of the above models enables accurate prediction of the steam generator water level.

[0160] In one embodiment, a specific implementation method for obtaining the predicted water level value of the steam generator is also provided, such as... Figure 6 As shown, step S103 above, "determining the predicted water level of the steam generator based on the steam pressure and mass flow rates," includes:

[0161] S301, based on the distance between the steam pressure value and the target steam pressure value, and the preset distance threshold, determine whether the steam pressure value meets the preset conditions.

[0162] Furthermore, in step S301, "determine whether the steam pressure value meets the preset conditions based on the distance between the steam pressure value and the target steam pressure value, and the preset distance threshold," the specific execution can be as follows: if the distance is less than the preset distance threshold, then the steam pressure value is determined to meet the preset conditions; if the distance is not less than the preset distance threshold, then the steam pressure value is determined not to meet the preset conditions.

[0163] The target steam pressure value is the measured value p of the main steam pressure in the operating parameters. ms .

[0164] In this embodiment, after obtaining the steam pressure value, the computer device can determine whether the distance between the steam pressure value and the target steam pressure value meets the convergence condition. For example, it can determine whether the absolute deviation between the two is less than a preset distance threshold. If the distance is less than the preset distance threshold, the steam pressure value is determined to meet the preset condition. If the distance is not less than the preset distance threshold, the steam pressure value is determined not to meet the preset condition. When the distance is not less than the preset distance threshold, the steam pressure value can be continuously corrected and updated until the steam pressure value meets the preset condition. Specifically, the distance between the steam pressure value and the target steam pressure value can be represented by the following relationship (41):

[0165] |p sp,out -pms |<ε (41);

[0166] Where, p sp,out This is the steam pressure value, in kPa; p ms ε is the target steam pressure value, in kPa; ε is the preset distance threshold, in kPa.

[0167] S302, when the steam pressure value meets the preset conditions, the mass flow rate value is input into the preset water level prediction model to predict the water level and obtain the predicted water level value of the steam generator.

[0168] The preset water level prediction model is the descending channel water supply chamber model.

[0169] In this embodiment of the application, when the computer device determines that the steam pressure value meets the preset conditions, it can calculate the mass flow rate D of the flash steam in the feedwater chamber of the descending channel from the mass flow rate value obtained in the above steps. fla Water supply mass flow rate D fw Recirculating water mass flow rate D rw and the preset descent channel working fluid mass flow rate D dc The water level is input into a preset water level prediction model to predict the water level, resulting in the predicted water level L of the steam generator. (See the steam generator water level prediction value for reference.) Figure 7 The real-time estimated water level in the steam generator and the measured water level in the steam generator (see [reference]). Figure 7 (Measured water level values) for example Figure 7 As shown, the horizontal axis represents time (min) and the vertical axis represents water level (m).

[0170] It can be seen that the predicted water level of the steam generator is very close to the measured water level. Therefore, a safety margin assessment of the water level development trend can be made based on the predicted water level of the steam generator to monitor the safe operation of the steam generator.

[0171] Specifically, the preset water level prediction model can be represented by the following relationships (42) to (44):

[0172]

[0173]

[0174]

[0175] Where L is the predicted water level of the steam generator, in meters; ρ dc1 It is h dc1 The corresponding working fluid density, in kg / m³.

[0176] The water level prediction method for steam generators provided in this application, by determining the distance between the steam pressure value and the target steam pressure value, can make the steam pressure value as close as possible to the actual measured value of the main steam pressure, and further make the predicted water level value closer to the measured value of the steam generator water level, thereby improving the accuracy of water level prediction.

[0177] In one embodiment, a method for predicting the water level of a steam generator is also provided, such as... Figure 8 As shown, Figure 2 The method described in the embodiments further includes:

[0178] S401, if the steam pressure value does not meet the preset conditions, the mass flow rate value is corrected according to the steam pressure value to obtain the corrected mass flow rate value.

[0179] In this embodiment of the application, when the steam pressure value does not meet the preset conditions, the computer device can adjust the preset descending channel working fluid mass flow rate D based on the convergence of the distance between the steam pressure value and the target steam pressure value. dc That is, by resetting D dc The value of is adjusted such that the distance between the steam pressure value and the target steam pressure value is less than a preset distance threshold, thus obtaining the corrected mass flow rate D of the working fluid in the descending channel. dc .

[0180] Mass flow rate D of the working fluid in the descending channel dc The method for making corrections can be expressed by the following relation (45):

[0181]

[0182] Among them, D dc i+1 This is the corrected mass flow rate of the working fluid in the descent channel, kg / s; D dc i-1 It is the mass flow rate of the working fluid in the descent channel of the previous cycle, p sp,out i-1 It is the working fluid pressure at the outlet of the steam-water separator corresponding to the working fluid mass flow rate in the previous step and the descending channel, and the initial D. dc 0 and p sp,out 0 Steady-state data can be used.

[0183] S402, input the corrected mass flow rate value into the steam generator model for estimation to obtain a new steam pressure value.

[0184] In this embodiment of the application, the computer device obtains the corrected descent channel working fluid mass flow rate D. dc i+1 After that, it can be based on Ddc i+1 Reuse Figure 2 The method in the embodiment estimates a new steam pressure value and repeats this process until the distance between the new steam pressure value and the target steam pressure value is less than a preset distance threshold, that is, the steam pressure value meets the preset condition.

[0185] S403, based on the new steam pressure value and the corrected mass flow rate value, return to the step of determining the predicted water level value of the steam generator based on the steam pressure value and the mass flow rate value.

[0186] In this embodiment, after the computer device obtains the steam pressure value and the corresponding mass flow rate value that meet the preset conditions based on the above steps, it can convert the steam pressure value that meets the preset conditions and the corrected mass flow rate D of the working fluid in the descending channel corresponding to the steam pressure value into a single value. dc i+1 The mass flow rate D of the flash steam in the feedwater chamber of the descending channel in the mass flow rate value. fla Water supply mass flow rate D fw and recirculated water mass flow rate D rw The water level is predicted by inputting the data into a preset water level prediction model to obtain the predicted water level value L of the steam generator.

[0187] The water level prediction method for a steam generator provided in this application improves the accuracy of water level prediction by correcting the mass flow rate when the steam pressure value does not meet the preset conditions. This makes the predicted water level value closer to the actual measured water level of the steam generator.

[0188] In summary, based on all the above embodiments, a method for predicting the water level of a steam generator is also provided, such as... Figure 9 As shown, the method includes:

[0189] S501, obtain the equipment parameters and operating parameters of the steam generator.

[0190] S502, the preset mass flow rate of the working fluid in the descending channel, equipment parameters and operating parameters are input into the descending channel model for estimation to obtain the mass flow rate of flash steam in the feedwater chamber of the descending channel.

[0191] S503, input the mass flow rate of flash steam in the feedwater chamber of the descending channel into the water level control system model for estimation, and obtain the feedwater mass flow rate.

[0192] S504, the preset working fluid mass flow rate, feed water mass flow rate, equipment parameters and operating parameters of the descending channel are input into the ascending channel model for estimation, so as to obtain the working fluid velocity in the preheating section of the ascending channel, the gas phase and liquid phase working fluid velocities in the boiling section of the ascending channel, and the working fluid cavitation rate in the boiling section of the ascending channel.

[0193] S505, determine the recirculated water mass flow rate based on the equipment parameters corresponding to the steam-water separator model.

[0194] S506, input the operating parameters and the above-mentioned mass flow rates into the loop resistance model for estimation to obtain a second estimation result; the second estimation result includes at least one of the following: pressure of the working medium in the feedwater chamber of the descending channel, pressure of the feedwater chamber outlet of the descending channel, pressure of the working medium in the annular gap of the descending channel, pressure of the annular gap outlet of the descending channel, pressure of the working medium in the preheating section of the ascending channel, pressure of the working medium in the boiling section of the ascending channel, pressure of the support orifice plate of the ascending channel, and pressure of the working medium at the inlet and outlet of the steam-water separator.

[0195] S507, determine the steam pressure value based on operating parameters and the second estimation result.

[0196] S508, based on the distance between the steam pressure value and the target steam pressure value, and the preset distance threshold, determine whether the steam pressure value meets the preset conditions.

[0197] S509, if the distance is less than the preset distance threshold, the steam pressure value is determined to meet the preset conditions; if the distance is not less than the preset distance threshold, the steam pressure value is determined not to meet the preset conditions.

[0198] S510: If the steam pressure value does not meet the preset conditions, the mass flow rate value is corrected according to the steam pressure value to obtain the corrected mass flow rate value.

[0199] S511, input the corrected mass flow rate value into the steam generator model for estimation to obtain a new steam pressure value.

[0200] S512, based on the new steam pressure value and the corrected mass flow rate value, return to the step of determining the predicted water level value of the steam generator according to the steam pressure value and the mass flow rate value.

[0201] S513, when the steam pressure value meets the preset conditions, the mass flow rate value is input into the preset water level prediction model to predict the water level and obtain the predicted water level value of the steam generator.

[0202] The predicted water level of the steam generator calculated based on the above embodiments using a nuclear power plant steam generator model can be used as an independent estimate of the steam generator water level, providing support for steam generator operation optimization and condition monitoring. In transient load changes, this method can be used for short-term forecasting of the steam generator water level, helping operators to promptly assess the water level trend and make safety margin assessments. It has potential application value for the implementation of water level emergency mechanisms and the safe and economical operation of nuclear power plants.

[0203] The methods described in each of the above steps have been described in the foregoing embodiments. For details, please refer to the foregoing descriptions. They will not be repeated here.

[0204] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0205] Based on the same inventive concept, this application also provides a steam generator water level prediction device for implementing the above-mentioned steam generator water level prediction method. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more steam generator water level prediction device embodiments provided below can be found in the limitations of the steam generator water level prediction method described above, and will not be repeated here.

[0206] In one embodiment, such as Figure 10 As shown, a water level prediction device for a steam generator is provided, comprising:

[0207] The acquisition module 10 is used to acquire the equipment parameters and operating parameters of the steam generator.

[0208] The estimation module 11 is used to input equipment parameters and operating parameters into the steam generator model for estimation, and obtain steam pressure value and mass flow rate value.

[0209] The prediction module 12 is used to determine the predicted water level of the steam generator based on the steam pressure value and the mass flow rate value.

[0210] In one embodiment, the estimation module 11 includes:

[0211] The first estimation unit is used to input the preset working fluid mass flow rate, equipment parameters and operating parameters of the descending channel into the loop model for estimation, and obtain the first estimation result. The first estimation result includes at least one of the following: flash steam mass flow rate of the descending channel feedwater chamber, feedwater mass flow rate, recirculated water mass flow rate, working fluid velocity of the preheating section of the ascending channel, gas phase and liquid phase working fluid velocities of the boiling section of the ascending channel, and working fluid cavitation rate of the boiling section of the ascending channel.

[0212] The second estimation unit is used to input the operating parameters and the first estimation result into the loop resistance model for estimation, and obtain the second estimation result. The second estimation result includes at least one of the following: pressure of the working medium in the feedwater chamber of the descending channel, pressure of the feedwater chamber outlet of the descending channel, pressure of the working medium in the annular gap of the descending channel, pressure of the annular gap outlet of the descending channel, pressure of the working medium in the preheating section of the ascending channel, pressure of the working medium in the boiling section of the ascending channel, pressure of the support orifice plate of the ascending channel, and pressure of the working medium at the inlet and outlet of the steam-water separator.

[0213] The first determining unit is used to determine the steam pressure value based on the operating parameters and the second estimation result.

[0214] In one embodiment, the first estimation unit mentioned above includes:

[0215] The first estimation subunit is used to input the preset mass flow rate of the working fluid in the descending channel, equipment parameters, and operating parameters into the descending channel model for estimation, so as to obtain the mass flow rate of flash steam in the feedwater chamber of the descending channel.

[0216] The second estimation subunit is used to input the mass flow rate of flash steam in the feedwater chamber of the descending channel into the water level control system model for estimation, so as to obtain the feedwater mass flow rate.

[0217] The third estimation subunit is used to input the preset working fluid mass flow rate, feed water mass flow rate, equipment parameters and operating parameters into the rising channel model for estimation, so as to obtain the working fluid flow rate in the preheating section of the rising channel, the gas phase and liquid phase working fluid flow rates in the boiling section of the rising channel, and the working fluid cavitation rate in the boiling section of the rising channel.

[0218] The sub-unit is determined based on the equipment parameters corresponding to the steam-water separator model to determine the recirculated water mass flow rate.

[0219] In one embodiment, the determining module 12 includes:

[0220] The second determining unit is used to determine whether the steam pressure value meets the preset conditions based on the distance between the steam pressure value and the target steam pressure value, as well as a preset distance threshold.

[0221] The prediction unit is used to input the mass flow rate value into the preset water level prediction model to predict the water level when the steam pressure value meets the preset conditions, so as to obtain the predicted water level value of the steam generator.

[0222] In one embodiment, the second determining unit is specifically used to determine that the steam pressure value meets the preset condition if the distance is less than a preset distance threshold; and to determine that the steam pressure value does not meet the preset condition if the distance is not less than the preset distance threshold.

[0223] In one embodiment, the water level prediction device for the steam generator further includes:

[0224] The correction module is used to correct the mass flow rate value based on the steam pressure value when the steam pressure value does not meet the preset conditions, so as to obtain the corrected mass flow rate value.

[0225] The re-prediction module is used to input the corrected mass flow rate value into the steam generator model for estimation, so as to obtain a new steam pressure value.

[0226] The loop module is used to return to the step of determining the predicted water level of the steam generator based on the new steam pressure value and the corrected mass flow rate value.

[0227] The modules in the water level prediction device of the aforementioned steam generator can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0228] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0229] Obtain the equipment parameters and operating parameters of the steam generator;

[0230] The equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values.

[0231] The predicted water level of the steam generator is determined based on the steam pressure and mass flow rate values.

[0232] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0233] Obtain the equipment parameters and operating parameters of the steam generator;

[0234] The equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values.

[0235] The predicted water level of the steam generator is determined based on the steam pressure and mass flow rate values.

[0236] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0237] Obtain the equipment parameters and operating parameters of the steam generator;

[0238] The equipment parameters and operating parameters are input into the steam generator model for estimation to obtain steam pressure and mass flow rate values.

[0239] The predicted water level of the steam generator is determined based on the steam pressure and mass flow rate values.

[0240] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0241] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0242] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for predicting the water level of a steam generator, characterized in that, The method includes: Obtain the equipment parameters and operating parameters of the steam generator. The equipment parameters are the structural parameters of the steam generator, including the cross-sectional area A of the feedwater chamber in the downflow channel. dc1 , the flow area A of the descending channel annular gap dc2 The upward channel circulation area A rc The cross-sectional area A of the steam-water separator sp The height H of the descending channel annular gap dc2 The height H from the bottom of the steam-water separator to the rotary vane sp1 The height H of the vapor separator vane to the top sp2 d, diameter of the water supply chamber in the descending channel dc1 , Outer radius R of the descending channel annulus dc2 , inner radius r of the descending channel annular gap dc2 Equivalent diameter d of the ascending channel e,rc Parameters; operating parameters are the operating data of the steam generator at a certain moment, including: the measured value of the primary coolant inlet temperature T. 1,in Measured value of primary coolant outlet temperature T 1,out Measured value of primary coolant mass flow rate D1, measured value of feedwater temperature T fw Measured value of main steam pressure p ms ; The steam generator model includes a loop model and a loop resistance model. The preset mass flow rate of the working fluid in the descending channel, the equipment parameters, and the operating parameters are input into the loop model for estimation to obtain a first estimation result. The first estimation result includes at least one of the following: flash steam mass flow rate in the descending channel feedwater chamber, feedwater mass flow rate, recirculated water mass flow rate, working fluid velocity in the ascending channel preheating section, gas and liquid phase working fluid velocities in the ascending channel boiling section, and working fluid cavitation rate in the ascending channel boiling section. The operating parameters and the first estimation result are input into the loop resistance model for estimation to obtain a second estimation result. The second estimation result includes at least one of the following: working fluid pressure in the descending channel feedwater chamber, descending channel feedwater chamber outlet pressure, descending channel annular gap working fluid pressure, descending channel annular gap outlet pressure, ascending channel preheating section working fluid pressure, ascending channel boiling section working fluid pressure, ascending channel support orifice plate pressure, and steam-water separator inlet and outlet working fluid pressures. The steam pressure value is determined based on the operating parameters and the second estimation result; Based on the distance between the steam pressure value and the target steam pressure value, and a preset distance threshold, determine whether the steam pressure value meets the preset conditions; When the steam pressure value meets the preset conditions, the values ​​of the flash steam mass flow rate of the water chamber, the feed water mass flow rate, and the recirculated water mass flow rate are input into the preset water level prediction model to predict the water level and obtain the predicted water level value of the steam generator.

2. The method according to claim 1, characterized in that, The loop model includes a descending channel model, a water level control system model, an ascending channel model, and a steam-water separator model. The process of inputting the preset descending channel working fluid mass flow rate, the equipment parameters, and the operating parameters into the loop model for estimation to obtain a first estimation result includes: The operating parameters are input into the descending channel model for estimation to obtain the flash steam mass flow rate of the descending channel feedwater chamber. The mass flow rate of flash steam in the feedwater chamber of the descending channel is input into the water level control system model for estimation to obtain the feedwater mass flow rate; The preset descending channel working fluid mass flow rate, the feed water mass flow rate, the equipment parameters, and the operating parameters are input into the ascending channel model for estimation to obtain the working fluid velocity in the preheating section of the ascending channel, the gas and liquid phase working fluid velocities in the boiling section of the ascending channel, and the working fluid cavitation rate in the boiling section of the ascending channel. The recirculated water mass flow rate is determined based on the equipment parameters corresponding to the steam-water separator model.

3. The method according to claim 2, characterized in that, The step of determining whether the steam pressure value meets the preset condition based on the distance between the steam pressure value and the target steam pressure value, and a preset distance threshold, includes: If the distance is less than the preset distance threshold, the steam pressure value is determined to meet the preset condition; if the distance is not less than the preset distance threshold, the steam pressure value is determined not to meet the preset condition.

4. The method according to claim 2, characterized in that, The method further includes: If the steam pressure value does not meet the preset condition, the mass flow rate value is corrected according to the steam pressure value to obtain the corrected mass flow rate value. The corrected mass flow rate value is input into the steam generator model for estimation to obtain a new steam pressure value; Based on the new steam pressure value and the corrected mass flow rate value, return to the step of determining the predicted water level value of the steam generator according to the steam pressure value and the mass flow rate value.

5. A water level prediction device for a steam generator, used to predict the water level of the steam generator according to any one of claims 1 to 4, characterized in that, The device includes: The acquisition module is used to acquire the equipment parameters and operating parameters of the steam generator; The prediction module is used to input the equipment parameters and the operating parameters into the steam generator model for estimation, and obtain steam pressure value and mass flow rate value; The determination module is used to determine the predicted water level of the steam generator based on the steam pressure value and the mass flow rate value.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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