Control method of molten salt steam generation system and molten salt steam generation system

Abstract

The application discloses a control method of a fused salt steam generation system and the fused salt steam generation system. The method comprises the following steps: determining a cross-influence coefficient and a transfer function of a superheater outlet steam pressure and a low-temperature fused salt storage tank inlet fused salt temperature according to real-time operation parameters; determining a double-variable nonlinear coupling model between the superheater outlet steam pressure and the low-temperature fused salt storage tank inlet fused salt temperature according to the cross-influence coefficient and the transfer function; constructing a decoupling matrix according to the double-variable nonlinear coupling model; determining the opening of a fused salt steam generation system inlet fused salt electric regulating valve according to a superheater outlet steam pressure deviation and a deviation change rate and combining the characteristics that the superheater outlet steam pressure independently responds to fused salt flow distribution adjustment after decoupling; and determining the opening of a high-temperature fused salt pump to a preheater outlet fused salt pipeline electric regulating valve according to a low-temperature fused salt storage tank inlet fused salt temperature deviation feedback and combining the characteristics that the low-temperature fused salt storage tank inlet fused salt temperature independently responds to fused salt flow distribution adjustment after decoupling.

Description

Technical Field

[0001] This application relates to the field of power grid technology, and in particular to a control method for a molten salt steam generation system and the molten salt steam generation system. Background Technology

[0002] In the actual operation of molten salt steam generation systems, existing technologies typically employ a control method that independently adjusts key parameters such as superheater outlet steam pressure and cryogenic molten salt inlet temperature. This is often achieved by indirectly adjusting molten salt circulation flow and equipment operating load to control a single target parameter. However, in actual molten salt steam generation systems, molten salt flow and heat exchange processes are intertwined. Changes in variables such as molten salt flow distribution and heat exchange load simultaneously affect multiple core parameters. There are coupling relationships between various devices and parameters, and independent adjustment of a single parameter inevitably interferes with other parameters, leading to decreased adjustment accuracy, excessive parameter fluctuations, and ultimately, the inability to achieve stable operation of the entire molten salt steam generation system. Summary of the Invention

[0003] In view of the above problems, this application provides a control method for a molten salt steam generation system and a molten salt steam generation system.

[0004] To solve the above-mentioned technical problems, this application proposes the following solution: In a first aspect, this application provides a control method for a molten salt steam generation system. The molten salt steam generation system includes: an electric regulating valve for molten salt at the inlet of the molten salt steam generation system and an electric regulating valve for the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet. The method includes: acquiring real-time operating parameters of the molten salt steam generation system; determining, based on the real-time operating parameters, the cross-influence coefficient between the superheater outlet steam pressure and the molten salt temperature at the inlet of the low-temperature molten salt storage tank, the transfer function of the superheater outlet steam pressure corresponding to the opening disturbance of the electric regulating valve for molten salt at the inlet of the molten salt steam generation system, and the transfer function of the molten salt temperature at the inlet of the low-temperature molten salt storage tank corresponding to the opening disturbance of the electric regulating valve for molten salt pipeline from the high-temperature molten salt pump to the preheater outlet; and determining, based on the cross-influence coefficient and the transfer function, a bivariate nonlinear coupling model between the superheater outlet steam pressure and the molten salt temperature at the inlet of the low-temperature molten salt storage tank. A bivariate nonlinear coupling model is used to indicate the dynamic correlation and mutual influence amplitude between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank under changes in molten salt flow distribution and heat exchange load. A decoupling matrix is ​​constructed based on the bivariate nonlinear coupling model to separate the cross-interference between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank. Based on the deviation and rate of change of the superheater outlet steam pressure, and considering the independent response of the decoupled superheater outlet steam pressure to the molten salt flow distribution regulation, the opening degree of the electric regulating valve at the inlet of the molten salt in the molten salt steam generation system is determined. Based on the deviation feedback of the cryogenic molten salt inlet temperature, and considering the independent response of the decoupled cryogenic molten salt inlet temperature to the molten salt flow distribution regulation, the opening degree of the electric regulating valve on the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is determined.

[0005] Secondly, this application provides a molten salt steam generating system, which includes: a high-temperature molten salt pump, a superheater, a preheater, an electric regulating valve for molten salt at the inlet of the molten salt steam generating system, and an electric regulating valve for the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet; one end of the electric regulating valve for molten salt at the inlet of the molten salt steam generating system is sealed to the outlet of the high-temperature molten salt pump, and the other end is sealed to the molten salt inlet of the superheater; one end of the electric regulating valve for the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is sealed to the outlet of the high-temperature molten salt pump, and the other end is sealed to the molten salt return pipeline on the outlet side of the preheater.

[0006] By employing the above-described technical solution, the technical solution provided in this application has at least the following advantages: This application determines the intensity and direction of their mutual interference by quantifying the cross-influence coefficient between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank. Simultaneously, it constructs transfer functions for the opening disturbances of two types of electric regulating valves and the corresponding core parameter changes to determine the mapping law between valve control actions and parameter dynamic responses. Based on the cross-influence coefficient and transfer function, a bivariate nonlinear coupling model reveals the dynamic correlation law and mutual influence amplitude of the two types of core parameters under molten salt flow distribution and heat exchange load changes, overcoming the neglect of parameter coupling relationships in existing technologies. Based on this coupling model, a decoupling matrix is ​​constructed, and through matrix linear transformation, the cross-interference of the two types of core parameters is completely separated, solving the mutual influence problem caused by independent control. Finally, combining the characteristics of the independent response of the core parameters to molten salt flow distribution regulation after decoupling, the opening of the two types of electric regulating valves is calculated based on steam pressure deviation and deviation change rate, and molten salt temperature deviation feedback, respectively, to achieve precise coordinated control of the core parameters and ensure the stable operation of the molten salt steam generation system.

[0007] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0008] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of a molten salt steam generation system provided in an embodiment of this application is shown; Figure 2 A schematic diagram of another molten salt steam generation system provided in an embodiment of this application is shown; Figure 3 A schematic diagram of another molten salt steam generation system provided in an embodiment of this application is shown; Figure 4 A schematic flowchart of a control method for a molten salt steam generation system provided in an embodiment of this application is shown. Detailed Implementation

[0009] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0010] In the embodiments of this application, the terms "first," "second," etc., do not have a logical or temporal dependency, nor do they limit the quantity or execution order. It should also be understood that although the following description uses the terms "first," "second," etc., to describe various elements, these elements should not be limited by the terms. These terms are merely used to distinguish one element from another.

[0011] In this application, the term "at least one" means one or more, and the term "multiple" means two or more.

[0012] It should also be understood that the term “if” can be interpreted as “when” or “upon”, or “in response to determination” or “in response to detection”. Similarly, depending on the context, the phrase “if determination…” or “if detection [the stated condition or event]” can be interpreted as “when determination…” or “in response to determination…” or “when detection [the stated condition or event]” or “in response to detection [the stated condition or event]”.

[0013] The molten salt steam generation system of this application will be described in detail below with reference to the accompanying drawings. Figure 1 This is a schematic diagram of a molten salt steam generation system provided in this application.

[0014] like Figure 1As shown, the molten salt steam generation system in this embodiment includes a high-temperature molten salt storage tank (1), a molten salt pipeline from the high-temperature molten salt storage tank to the high-temperature molten salt pump (2), a high-temperature molten salt pump (3), a molten salt pipeline from the high-temperature molten salt pump to the superheater (5), an electric regulating valve for the molten salt inlet of the molten salt steam generation system (6), a superheater (7), a molten salt pipeline from the superheater to the evaporator (8), an evaporator (9), a molten salt pipeline from the evaporator to the preheater (10), a preheater (11), a molten salt pipeline from the high-temperature molten salt pump to the preheater outlet (12), and an electric regulating valve for the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet. The equipment is connected by a dedicated pipeline, forming a complete molten salt circulation and heat exchange process. The pipeline consists of a control valve (13), a molten salt pipeline from the preheater to the low-temperature molten salt storage tank (15), a low-temperature molten salt storage tank (16), a deaerator (17), an electric feed water pump (18), a feed water pipeline from the deaerator to the preheater (21), a steam-water pipeline from the preheater to the steam drum (26), a downcomer from the steam drum (27), a steam drum (29), a riser from the steam drum (30), a steam pipeline from the steam drum to the superheater (31), a steam pipeline from the superheater to the steam supply manifold (34), and a steam supply manifold (37).

[0015] The high-temperature molten salt storage tank is connected to the inlet of the high-temperature molten salt pump via a molten salt pipeline. Its function is to store high-temperature molten salt and provide a stable source of high-temperature molten salt for the entire system. The high-temperature molten salt pump outlet is divided into two paths: one path connects to the superheater via an electric regulating valve at the inlet of the molten salt steam generation system and the molten salt pipeline from the high-temperature molten salt pump to the superheater; the other path connects to the return pipeline on the preheater outlet side via an electric regulating valve on the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet and the same pipeline. The high-temperature molten salt pump provides the power for the circulation of molten salt within the system. The electric regulating valves at the inlet of the molten salt steam generation system and the high-temperature molten salt pipeline from the high-temperature molten salt pump to the preheater outlet are used to precisely control the flow rate of molten salt to the superheater and the return pipeline from the preheater outlet, respectively, ensuring a stable heat exchange process.

[0016] The superheater is connected to the evaporator via a molten salt pipe from the superheater to the evaporator, and also to the steam drum via a steam pipe from the steam drum to the superheater. Its function is twofold: to receive heat from the high-temperature molten salt and to further heat the saturated steam from the steam drum, generating superheated steam that meets user requirements. The evaporator is connected to the preheater via a molten salt pipe from the evaporator to the preheater, and forms a closed loop with the steam drum via a downcomer and an upcomer. Its main function is to utilize the waste heat from the molten salt flowing out of the superheater to heat the water inside, causing it to vaporize and produce a saturated steam-water mixture, while simultaneously transferring the heat from the molten salt.

[0017] The preheater is connected to the cryogenic molten salt storage tank via a molten salt pipeline, and also to the deaerator via a feedwater pipeline from the deaerator to the preheater. Furthermore, it is connected to the steam drum via a steam-water pipeline from the preheater to the steam drum. Its function is to preheat the feedwater from the deaerator using the molten salt, which still retains residual heat after flowing through the evaporator, thereby increasing the feedwater temperature, improving the overall system's heat exchange efficiency, and reducing energy waste. The cryogenic molten salt storage tank receives the cryogenic molten salt from the preheater and stores it for subsequent recycling.

[0018] The deaerator is connected to the electric feedwater pump and also to the preheater via a feedwater pipeline. Its function is to remove oxygen and other gases from the feedwater, preventing oxygen from corroding the equipment and pipes within the system and ensuring long-term stable operation. The electric feedwater pump provides the power to transport feedwater from the deaerator to the preheater, ensuring a stable feedwater supply.

[0019] The steam drum forms a circulation loop with the evaporator through its downcomer and riser pipes. It is also connected to the superheater via a steam pipe from the steam drum to the superheater, serving as the core hub of the steam-water circulation. Its function is to separate the steam-water mixture produced by the evaporator, transport saturated steam to the superheater, and simultaneously return the water to the evaporator for further heating, maintaining a stable steam-water circulation. The superheated steam generated by the superheater is transported to the steam supply header via a steam pipe from the superheater to the header. The header collects the superheated steam and distributes it stably and evenly to various heating users to meet their steam demands.

[0020] Based on the structure and circulation logic of the molten salt steam generation system described above, this embodiment optimizes and upgrades the molten salt steam generation system by adding technical designs related to precise control and efficient heat exchange, such as... Figure 2 As shown, the molten salt steam generation system in this embodiment also includes an electric regulating valve (20) for molten salt steam generation system feedwater, a feedwater pipeline (24) from the preheater outlet to the deaerator, and an electric regulating valve (25) from the preheater outlet to the deaerator feedwater pipeline. Each new component is seamlessly connected to the original system, further improving the stability and heat exchange efficiency of the system operation.

[0021] The electric regulating valve for the molten salt steam generation system feedwater is installed on the feedwater pipeline from the deaerator to the preheater. One end is connected to the feedwater pipeline output from the deaerator, and the other end is connected to the feedwater inlet pipeline of the preheater. Its function is to precisely adjust the feedwater flow rate into the preheater according to the real-time operating requirements of the molten salt steam generation system. Specifically, the electric regulating valve for the molten salt steam generation system feedwater can be linked to the steam and water parameters (such as temperature and pressure) at the preheater outlet. When the feedwater temperature at the preheater outlet is too high or too low, the feedwater flow rate is changed by adjusting the valve opening, so that the heat exchange between the feedwater and the molten salt in the preheater reaches a dynamic balance. This avoids unstable preheating effect due to fluctuations in feedwater flow, and can also adapt to the feedwater requirements under different system loads, ensuring a stable supply of steam and water circulation.

[0022] One end of the preheater outlet to deaerator feedwater pipeline is connected to the preheater feedwater outlet pipeline, and the other end is connected to the deaerator inlet, forming a feedwater return branch. An electric regulating valve for the preheater outlet to deaerator feedwater pipeline is installed on this return pipeline to control the flow rate of the return feedwater. This return branch serves multiple purposes: First, when the preheater outlet feedwater temperature approaches the saturation temperature at the current pressure, the electric regulating valve can be opened in advance to increase the feedwater flow rate in the preheater, returning some feedwater to the deaerator and preventing localized vaporization of the feedwater in the preheater, effectively ensuring system operational safety. Second, the return pipeline increases the feedwater flow rate in the preheater, improving the preheater's heat exchange capacity and preventing excessively high molten salt temperatures returning to the low-temperature molten salt storage tank, thus fully utilizing the molten salt energy. Third, by adjusting the feedwater return flow rate, the consumption of other heating steam sources in the deaerator can be reduced, further optimizing the overall system's heat exchange efficiency and reducing energy consumption.

[0023] Furthermore, such as Figure 3 As shown, this embodiment adds an electric regulating valve (35) for steam from the superheater to the steam supply manifold, a desuperheating water pipeline (38), an electric regulating valve (39) for desuperheating water, and desuperheating water (40) to the optimized molten salt steam generation system. It is also equipped with key measuring points such as the molten salt pressure (4) at the outlet of the high-temperature molten salt pump, the molten salt temperature (14) at the inlet of the low-temperature molten salt storage tank, the steam-water pressure (22) at the outlet of the preheater, the steam-water temperature (23) at the outlet of the preheater, the water supply pressure (19) at the outlet of the electric feedwater pump, the liquid level in the steam drum (28), the steam pressure (32) at the outlet of the superheater, the steam temperature (33) after the desuperheating water, and the steam flow rate (36) from the superheater to the steam supply manifold.

[0024] The connection methods and functions of each newly added component and measuring point are as follows: The electric steam regulating valve from the superheater to the steam supply header is installed on the steam pipeline from the superheater to the steam supply header. One end is connected to the steam outlet side of the superheater, and the other end is connected to the inlet of the steam supply header. Its function is to dynamically adjust the steam delivery flow rate according to the user's load demand, and to achieve precise flow control in conjunction with the steam flow measuring point from the superheater to the steam supply header. When the flow measuring point detects a deviation between the actual flow rate and the demand, the regulating valve corrects the flow rate by adjusting the opening, responding promptly to the steam supply flow demand. One end of the desuperheating water pipeline is connected to an external qualified desuperheating water source, and the other end is connected to the key mixing area of ​​the steam pipeline from the superheater to the steam supply header. The electric desuperheating water regulating valve is installed on the desuperheating water pipeline as the actuator for temperature control. It is linked with the steam pressure measuring point at the superheater outlet and the steam temperature measuring point after the desuperheating water. It injects desuperheating water into the steam using an atomized spray method. By adjusting the amount of desuperheating water injected, the steam temperature is corrected to ensure that the output steam temperature is stable within the set range, effectively avoiding the impact of temperature deviation on heating quality.

[0025] The molten salt pressure measuring point at the outlet of the high-temperature molten salt pump is installed on the outlet pipeline of the high-temperature molten salt pump to collect molten salt delivery pressure data in real time, providing a basis for molten salt flow regulation and pump group safety protection. When the pressure exceeds the safety threshold, the pump group operating parameters can be adjusted in conjunction with the pump, or a protection action can be triggered. The molten salt temperature measuring point at the inlet of the low-temperature molten salt storage tank is arranged on the molten salt pipeline from the preheater to the low-temperature molten salt storage tank to continuously monitor the temperature of the molten salt entering the tank, preventing the molten salt from solidifying and clogging the pipeline due to excessively low temperature. The feedwater pressure measuring point at the outlet of the electric feedwater pump is installed between the electric feedwater pump and the feedwater pipeline from the deaerator to the preheater to ensure stable feedwater delivery pressure and lay the foundation for feedwater flow regulation. The steam-water pressure and temperature measuring points at the preheater outlet are both located on the preheater outlet side, synchronously collecting pressure and temperature data of the preheated feedwater to provide feedback on the preheating effect and provide data support for adjusting the opening of the electric regulating valve of the molten salt steam generation system. The steam drum level measuring point is installed on the steam drum body to accurately monitor the liquid level height inside the steam drum, ensuring stable steam-water circulation. The superheater outlet steam pressure measuring point, the desuperheating water steam temperature measuring point, and the superheater to steam supply header steam flow measuring point are arranged sequentially on the steam pipeline from the superheater outlet to the steam supply header to comprehensively capture steam quality and transportation parameters, forming a multi-dimensional control basis.

[0026] To achieve precise control of various parameters in the molten salt steam generation system and ensure stable and efficient system operation, this embodiment configures a comprehensive automatic control strategy for the above-mentioned system components. Specifically, it includes two parts of automatic control logic: one for the steam-water side and one for the molten salt side. Each control loop works together to form a closed-loop control system.

[0027] The electric regulating valve for feedwater in the molten salt steam generation system is put into automatic mode. The steam drum liquid level is the controlled variable, and the set value is selected as the standard value within the normal liquid level range of the steam drum. When the steam drum liquid level is lower than the set value, the opening of the regulating valve is automatically increased through the PID control algorithm to increase the feedwater flow to replenish the liquid level. When the steam drum liquid level is higher than the set value, the opening is automatically reduced to decrease the feedwater flow until the steam drum liquid level stabilizes within the set value range, thus providing stable core parameter support for steam-water circulation.

[0028] To complement this, the electric feedwater pump is placed in automatic control mode, with the feedwater pressure at the outlet of the electric feedwater pump as the controlled variable. Its set value needs to be determined after considering parameters such as the real-time opening of the electric regulating valve of the molten salt steam generation system and the steam pressure at the outlet of the superheater to determine the required water pressure of the system. When the feedwater pressure at the outlet of the electric feedwater pump is lower than the set value, the frequency of the pump inverter is increased through the PID control algorithm to enhance the output pressure. When it is higher than the set value, the frequency of the inverter is reduced to decrease the output pressure, ensuring that the feedwater pressure is stably matched with the system's operating requirements.

[0029] To address the preheater's anti-vaporization requirements, the electric regulating valve in the feedwater pipeline from the preheater outlet to the deaerator is put into automatic operation. The difference between the water saturation temperature corresponding to the preheater outlet steam-water pressure and the preheater outlet steam-water temperature is used as the controlled variable. The setpoint is configured according to the anti-vaporization requirements of the actual operating conditions. When the difference is lower than the setpoint, it means that there is a risk of feedwater vaporization. The PID control algorithm is used to increase the opening of the regulating valve to increase the water flow to the preheater and reduce the rate of feedwater temperature rise. When the difference is higher than the setpoint, the opening is reduced to decrease the return water flow, ensuring that the feedwater temperature is always lower than the saturation temperature at the corresponding pressure.

[0030] In terms of steam temperature control, the electric regulating valve for desuperheating water is incorporated into automatic control. The steam temperature after desuperheating water is the controlled variable, and the set value can be flexibly adjusted according to the actual heating temperature requirements. When the steam temperature after desuperheating water is higher than the set value, the PID control algorithm increases the opening of the regulating valve to increase the amount of desuperheating water injected to reduce the steam temperature. When it is lower than the set value, the opening is reduced to decrease the amount of injection, so that the steam temperature can be stably met to meet the requirements of various heating scenarios.

[0031] To adapt to changes in heating load, the electric steam regulating valve from the superheater to the steam supply header is put into automatic mode. The steam flow rate from the superheater to the steam supply header is the controlled variable, and the set value is determined according to the actual heating flow rate requirement. When the steam flow rate is lower than the set value, the PID control algorithm increases the valve opening to increase the steam delivery rate. When the steam flow rate is higher than the set value, the valve opening is reduced to decrease the delivery rate, ensuring that the steam flow rate accurately matches the heating load.

[0032] The automatic control on the molten salt side complements the regulation on the steam-water side. The electric regulating valve at the inlet of the molten salt steam generation system is put into automatic control. The superheater outlet steam pressure is the controlled variable, and the set value is set according to the actual heating pressure requirement. When the superheater outlet steam pressure is lower than the set value, the PID control algorithm increases the opening of the regulating valve to increase the flow of molten salt into the superheater, improve the heat exchange intensity, and raise the steam pressure. When it is higher than the set value, the opening is reduced to decrease the flow of molten salt and weaken the heat exchange intensity, so that the steam pressure is stabilized within the set range.

[0033] As the core power source for molten salt circulation, the high-temperature molten salt pump is placed in automatic operation mode. The molten salt pressure at the outlet of the high-temperature molten salt pump is the controlled variable. The set value needs to be determined by considering the real-time opening of the electric regulating valve at the inlet of the molten salt steam generation system and the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the outlet of the preheater. When the molten salt pressure at the outlet of the high-temperature molten salt pump is lower than the set value, the frequency of the inverter is increased through the PID control algorithm to enhance the molten salt delivery pressure. When it is higher than the set value, the frequency of the inverter is reduced to decrease the delivery pressure, ensuring that the molten salt pressure is adapted to the system circulation requirements.

[0034] To address the need for molten salt anti-condensation, the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is put into automatic control. The molten salt temperature at the inlet of the low-temperature molten salt storage tank is the controlled variable. For ternary Hitec molten salt, the set value is usually 190℃, but it can be adjusted according to the type of molten salt and system design requirements. When the molten salt temperature at the inlet of the low-temperature molten salt storage tank is lower than the set value, the opening of the regulating valve is increased through the PID control algorithm to increase the flow rate of high-temperature molten salt directly returning to the preheater outlet, thereby increasing the molten salt temperature entering the low-temperature molten salt storage tank. When it is higher than the set value, the opening is reduced to decrease the return flow rate, so that the molten salt temperature is stabilized within the anti-condensation set value range.

[0035] The aforementioned automatic control strategy achieves precise linkage between various controlled variables and actuators through PID control algorithms, ensuring stable control of key parameters on both the steam-water and molten salt sides, and realizing efficient coordination of the overall system operation. This effectively improves the operational stability, control accuracy, and energy utilization efficiency of the molten salt steam generation system.

[0036] To achieve precise control of key parameters on both the molten salt and steam / water sides of the molten salt steam generation system, eliminate coupling interference between variables, and ensure the continuous, stable, and efficient operation of the molten salt steam generation system under various operating conditions, this application establishes a more comprehensive control logic system based on the system structure and component configuration described above. This control method focuses on the dynamic correlation laws of core parameters, forming a closed-loop control mechanism for molten salt flow distribution and equipment operating status through coupling model construction, cross-interference decoupling, and precise parameter adjustment. The control method for the molten salt steam generation system is described in detail below with reference to the accompanying drawings. Figure 4A flowchart illustrating a control method for a molten salt steam generation system provided in this application is shown. Specifically, it includes the following steps: Step 410: Collect real-time operating parameters of the molten salt steam generation system.

[0037] The real-time operating parameters of the molten salt steam generation system collected in this application cover the core indicators of the molten salt side, the steam-water side, and the equipment control side. Through standardized data acquisition and transmission processes, the accuracy, continuity, and timeliness of the parameters are ensured.

[0038] Regarding the acquisition of key parameters on the molten salt side, the molten salt pressure at the outlet of the high-temperature molten salt pump is collected from the outlet pipeline. The molten salt temperature at the inlet of the low-temperature molten salt storage tank is collected from the molten salt pipeline from the preheater to the low-temperature molten salt storage tank. Real-time valve opening data is acquired from the actuators of the electric regulating valves at the inlet of the molten salt steam generation system and the electric regulating valves on the molten salt pipeline from the high-temperature molten salt pump to the outlet of the preheater. Molten salt flow rate data is collected from the molten salt pipelines from the high-temperature molten salt pump to the superheater and preheater.

[0039] For steam-water side parameter acquisition, the superheater outlet steam pressure, flow rate, and temperature are simultaneously collected on the superheater outlet steam pipeline. The preheater outlet steam-water pressure and temperature are collected on the preheater outlet steam-water pipeline. The real-time water level of the deaerator is monitored on the deaerator body; the feedwater pressure and flow rate are collected on the electric feedwater pump outlet pipeline. The steam drum liquid level is monitored in real-time on the steam drum body.

[0040] For equipment control-side parameter acquisition, real-time opening signals of key valves such as the electric regulating valve for feedwater in the molten salt steam generation system and the electric regulating valve for feedwater from the preheater outlet to the deaerator are read through the system PLC or DCS controller. Inverter operating parameters of the high-temperature molten salt pump and electric feedwater pump, including output frequency, current, and voltage, are also collected. Real-time heating steam load data is acquired through the steam flow sensor in the steam supply header.

[0041] Step 420: Determine the cross-influence coefficient and transfer function based on the real-time operating parameters.

[0042] Based on the collected real-time operating parameters, through multi-dimensional data processing, characteristic analysis and mathematical modeling, the cross-influence coefficient between the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank, as well as the transfer functions corresponding to the opening disturbances of the two types of electric regulating valves, are accurately determined.

[0043] In calculating the cross-influence coefficient, the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank are used as core correlation parameters. Real-time opening data of the electric regulating valves at the inlet of the molten salt steam generation system and the electric regulating valves in the pipeline from the high-temperature molten salt pump to the preheater outlet molten salt pipeline are simultaneously incorporated, along with auxiliary parameters such as the preheater outlet steam-water pressure and preheater outlet steam-water temperature, to construct a complete multi-parameter analysis dataset. By quantitatively analyzing the impact of changes in superheater outlet steam pressure on the inlet molten salt temperature of the cryogenic molten salt storage tank, and simultaneously quantifying the amplitude of the effect of changes in the inlet molten salt temperature of the cryogenic molten salt storage tank on the superheater outlet steam pressure, a cross-influence coefficient that accurately reflects the intensity and direction of their interaction is formed.

[0044] In one specific implementation, the collected real-time operating parameters are first preprocessed. Outliers are identified and removed using the Grubbs criterion. A significance level of α = 0.05 is set, and the mean μ and standard deviation σ of each parameter are calculated. If a data point satisfies |x i If -μ|>G(α,n)×σ (where G(α,n) is the critical value of the Grubbs' test and n is the data sample size), it is considered an outlier and removed. For missing values, corresponding processing methods are adopted according to the missing data ratio. When the missing ratio is less than 5%, linear interpolation is used to fill in the missing values; when the missing ratio is between 5% and 15%, the nearest neighbor mean is used to fill in the missing values; when the missing ratio is greater than 15%, the data for that period is re-collected to ensure data integrity. Data smoothing uses the moving average method, and the sliding window size is set to N=5 (the window size can be dynamically adjusted according to the data sampling frequency; N is 8 when the sampling frequency is higher than 20Hz, and N is 3 when the sampling frequency is lower than 10Hz). The formula is used to smooth the data. (k is the index of the current data point) Calculate the smoothed data value to effectively reduce data fluctuations caused by random interference and ensure the reliability and continuity of the data.

[0045] Subsequently, Pearson correlation analysis was used to calculate the linear correlation coefficient. First, the analysis sample set was determined, selecting data collected within one hour of continuous operation, with a sample size of no less than 1000 sets. The superheater outlet steam pressure data sequence was recorded as follows: The data sequence of molten salt temperature at the inlet of the cryogenic molten salt storage tank is as follows: Calculate the mean of X and Y using the formula. covariance Standard deviation Finally, the Pearson linear correlation coefficient was obtained. The strength of the correlation is initially determined based on the value of r: |r|≥0.8 indicates an extremely strong linear correlation, 0.6≤|r|<0.8 indicates a strong linear correlation, 0.4≤|r|<0.6 indicates a moderate linear correlation, 0.2≤|r|<0.4 indicates a weak linear correlation, and |r|<0.2 indicates an extremely low linear correlation. This completes the preliminary determination of the linear correlation characteristics of the two types of parameters.

[0046] Based on this, a dynamic time warping algorithm is introduced to align the time series. First, a distance matrix D between X and Y is constructed, and the matrix elements... Let represent the Euclidean distance between the i-th data point in X and the j-th data point in Y. Then, the cumulative distance matrix D is defined. acc D acc (1,1)=d(1,1), for i>1 and j=1, D acc (i,1)=D acc (i-1,1)+d(i,1); for j>1 and i=1, D acc (1,j)=D acc (1,j-1)+d(1,j); for i>1 and j>1, D acc (i,j)=d(i,j)+min(D acc (i-1,j),D acc (i,j-1),D acc (i-1,j-1)), find the path from D using dynamic programming algorithm. acc (1,1) to D acc The minimum cumulative distance path of (n,n) is the index mapping relationship corresponding to the path, which is the time alignment result of the two types of parameter sequences, effectively eliminating the time misalignment caused by factors such as system transmission delay and sensor response lag.

[0047] To quantify the degree of nonlinear correlation, the mutual information entropy of the aligned sequences is calculated. First, the aligned pressure sequence X' and temperature sequence Y' are discretized. The equal-frequency binning method is used to divide X' and Y' into m=10 intervals respectively (the number of bins can be adjusted according to the data distribution characteristics; m is 8-12 when the data distribution is uniform, and unequal-distance binning is used when the distribution is uneven). The marginal probability P(X'=a) of X' falling into each interval is then calculated. k (k=1,2,...,m), the marginal probability P(Y'=b1) (l=1,2,...,m) of Y' falling in each interval, and X'=a k And the joint probability P(X'=a) of Y'=b1 k ,Y'=b1). Through the formula Calculate the mutual information entropy. The larger the value of I(X';Y'), the stronger the nonlinear correlation between the two types of parameters. The value ranges from 0 to min(H(X'),H(Y')) (H(X') and H(Y') are the information entropies of X' and Y', respectively).

[0048] A comprehensive correlation index is constructed by combining the linear correlation coefficient and mutual information entropy, and a weighted summation formula is used. ,in These are weighting coefficients, set according to the system's operating characteristics. (When the linear characteristic is significant, it can be adjusted to) ), I max The theoretical maximum value of mutual information entropy (i.e., min(H(X'), H(Y'))) is obtained by passing I(X';Y') / I max The mutual information entropy is normalized to the [0,1] interval to ensure consistency with the dimensions of |r|. The comprehensive correlation index CI is standardized using the min-max standardization formula CI. std =(CI-CI min ) / (CI max -CI min ), where CI min CI max The minimum and maximum values ​​of the comprehensive correlation index calculated from multiple groups of samples are respectively, so that CI std It falls within the [0,1] interval and serves as the core component of the cross-influence coefficient.

[0049] Finally, adjustments were made based on indirect influencing factors. The changes in molten salt flow distribution ΔQ (calculated by combining the changes in the opening of two types of electric regulating valves with the pipeline flow characteristics) and the fluctuations in preheater heat exchange efficiency Δη (calculated based on the preheater inlet and outlet temperature, pressure, and flow data, using the heat balance equation to calculate the difference between the actual and designed heat exchange efficiency) were selected as adjustment variables to construct a multiple linear regression model. ,in Here, ε represents the regression coefficients, and ε is the random error term. By collecting over 30 sets of sample data under different operating conditions, the regression coefficients are solved using the least squares method: The design matrix is ​​then constructed. dependent variable vector Through formula Solving for regression coefficients ( For constant terms, incorporate CI std The significance of the regression coefficients was verified using a t-test (significance level α = 0.05), and insignificant correction terms were removed. Simultaneously, the coefficient of determination R² was calculated to ensure R² ≥ 0.8, guaranteeing the good fit of the corrected model. The final CI was then obtained. final This is the cross-influence coefficient, and its sign is determined by the sign of the Pearson correlation coefficient r (when r is positive, CI...).final CI is positive when r is negative final (Negative), the value reflects the strength of the interaction between the two types of parameters, and realizes the accurate quantification of the cross influence of the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank.

[0050] In constructing the transfer function for the electric regulating valve at the inlet of the molten salt steam generation system, a step disturbance of a specific amplitude is applied to the valve's opening. Simultaneously, the dynamic response data of the superheater outlet steam pressure triggered by this disturbance is recorded, covering key indicators such as initial pressure value, peak value, response time, and steady-state value. Real-time data of the molten salt pressure at the outlet of the high-temperature molten salt pump is also collected. Combining the system's fluid dynamics characteristics and pipeline resistance loss patterns, the pressure data is corrected to eliminate interference from pipeline resistance, resulting in corrected data for the high-temperature molten salt pump outlet pressure. Based on the valve opening step change, the corresponding steam pressure response data, and the corrected pressure data, a transfer function model is constructed using a system identification method. This model accurately describes the dynamic mapping relationship between the valve opening disturbance and the change in superheater outlet steam pressure, clarifying their interaction patterns and response characteristics.

[0051] In one specific implementation, the first step change in valve opening is set. This step change is determined based on a combination of the system's rated operating parameters and the valve's characteristic curve, balancing system response sensitivity and operational safety. For electrically operated control valves with a nominal diameter of DN50-DN100, 5%-8% of the valve's rated opening is selected; for valves with a nominal diameter greater than DN100, 8%-10% of the rated opening is selected, ensuring that the step disturbance triggers an observable pressure response without causing system parameter overshoot exceeding the safety threshold.

[0052] Before applying a step change, the system should be kept in stable operating condition for at least 30 minutes. The stability criteria are: superheater outlet steam pressure fluctuation ≤ ±0.05MPa, high-temperature molten salt pump outlet molten salt pressure fluctuation ≤ ±0.1MPa, and preheater outlet steam-water temperature fluctuation ≤ ±2℃. At this time, key initial parameters should be recorded, including the initial value of superheater outlet steam pressure P0 and the initial value of high-temperature molten salt pump outlet molten salt pressure P... p0 The initial opening θ0 of the molten salt electric regulating valve at the inlet of the molten salt steam generation system, and the steam-water pressure P at the outlet of the preheater. q0 and the temperature of the steamed water T q0 .

[0053] After applying a step change, continuously collect the superheater outlet steam pressure response data at a sampling frequency of 15Hz (higher than the minimum requirement of 10Hz to improve data timeliness). The collection duration is set from the moment the step change is applied until the pressure fluctuation range is ≤ ±0.02MPa for 10 consecutive seconds, ensuring coverage of the pressure change from the initial value P0 to the new steady-state value P.ss The complete process. Extracting dynamic response characteristic parameters from the acquired data: response delay time τ. d (Time from step application to pressure deviation from P0±0.01MPa), rise time T r (The time it takes for the pressure to rise from P0+10%ΔP to P0+90%ΔP, where ΔP=P) ss -P0), peak time T p (Pressure reaches peak response P) p Time), overshoot New steady-state value P ss This forms a complete dynamic response curve.

[0054] Simultaneously, real-time data P of the molten salt pressure at the outlet of the high-temperature molten salt pump is collected. p (t), based on the pipeline resistance calculation formula ΔP=λ×(L / D)×(ρv) 2 / 2) Pressure correction is performed. The pipe friction coefficient λ is determined based on the pipe material and molten salt flow velocity. For carbon steel pipes, it is taken as 0.025-0.035 within the molten salt flow velocity range of 0.5-2 m / s, and the accurate value is obtained through interpolation using Moody's charts. The pipe length L and inner diameter D are based on actual measurements. The molten salt density ρ is calculated based on the real-time collected molten salt temperature using the empirical formula ρ=2080-0.65T (T is the molten salt temperature). The molten salt flow velocity v is calculated using the molten salt flow rate Q collected by the flow sensor and the pipe cross-sectional area S, i.e., v=Q / S, and the pipe cross-sectional area S=π×(D / 2). 2 (D is the pipe inner diameter). Based on the above parameters, calculate the theoretical pressure loss value ΔP(t) at different times, and then use the formula P... pcorr (t)=P p (t)-ΔP(t) yields the corrected molten salt pressure data at the outlet of the high-temperature molten salt pump, eliminating the interference of pipeline resistance on pressure measurement.

[0055] Based on the first valve opening step change Δθ = θ1 - θ0 (θ1 is the valve opening after the step change), the corresponding superheater outlet steam pressure response data P(t), and the high-temperature molten salt pump outlet molten salt pressure correction data P pcorr (t) The transfer function model is constructed using the least squares method in system identification. First, it is assumed that the transfer function is a first-order inertial plus pure time-delay model. , where K is the gain, τ is the pure time delay, and T is the time constant.

[0056] With the corrected pressure data P pcorrLet u(t) be the input variable and P(t) be the superheater outlet steam pressure response data. Let y(t) be the output variable. Construct a data matrix: organize u(t) and y(t) into N sets of data according to the sampling time series (N is the total number of data collected), forming an input vector U=[u(1),u(2),...,u(N)]. T The output vector is Y = [y(1), y(2), ..., y(N)]. T Minimize the sum of squared residuals S using the least squares method. ( To predict the output value of the model, solve for the model parameters: First, discretize the first-order inertial plus pure time-delay model using a zero-order hold and a sampling period T0 = 1 / 15s to obtain the discretized model. ,in The design matrix X is constructed based on the discretized model, where the k-th row of X is... Through formula Solve for the discretization parameters a and b, and then... Back-calculation of time constant ,pass Back-dive gain The pure time delay τ is through the response delay time τ d With system transmission delay τ t Superposition determines (τ=τ) d +τ t , τ t The initial values ​​of parameters K0, τ0, and T0 are obtained by testing the sensor response time and data transmission delay (typically 0.02-0.05s).

[0057] The parameters were then iteratively optimized using gradient descent, with a learning rate η = 0.001 and an upper limit of 1000 iterations. In each iteration, the partial derivatives of the sum of squared residuals S with respect to each parameter were calculated. ,according to , Update parameters until the sum of squared residuals S < 10 -5 Or it may reach the maximum number of iterations.

[0058] Finally, the frequency characteristics of the model were analyzed using Bode plots: the amplitude and phase frequency characteristics of the model in the frequency range of 0.01-10 rad / s were calculated and compared with the frequency response data of the actual system (obtained through a sinusoidal sweep experiment, with a sweep range of 0.01-10 rad / s and a step size of 0.05 rad / s). The amplitude-frequency error δA was calculated as δA = |20lg|G(jω)| - 20lg|G actual The maximum value of (jω)∣∣ and the phase frequency error The maximum value. If δA≤3dB and If the fitting accuracy meets the requirements, the transfer function model is upgraded to a second-order inertial plus pure time-delay model. , where T1 and T2 are two time constants.

[0059] Repeat the discretization, parameter initialization, and iterative optimization process described above for the second-order model: discretization uses a zero-order hold, resulting in... ,in , , The discretized parameters a1, a2, b1, and b2 are solved by the least squares method, and the initial values ​​of K, τ, T1, and T2 are obtained by reverse deduction. Then, the gradient descent method is used for optimization until the model output fits the actual superheater outlet steam pressure response data with a goodness of fit R2 ≥ 95%. Finally, the superheater outlet steam pressure transfer function corresponding to the opening disturbance of the electric regulating valve is determined.

[0060] Regarding the construction of the transfer function for the electric regulating valve in the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet, referring to the construction logic of the valve transfer function mentioned above, a step change in valve opening with a set amplitude is applied. The corresponding data on the temperature-related changes of the molten salt at the inlet of the low-temperature molten salt storage tank are monitored and recorded in real time, covering key information such as temperature change amplitude, response rate, and steady state. Similarly, the molten salt pressure at the outlet of the high-temperature molten salt pump is corrected to obtain the corresponding pressure correction data. Based on the step change in valve opening, the temperature-related changes of molten salt, and the pressure correction data, the transfer function between the valve opening disturbance and the temperature change of the molten salt at the inlet of the low-temperature molten salt storage tank is established through a system identification method, clarifying the dynamic interaction law between the two.

[0061] In one specific implementation, the second opening step change of the electric regulating valve at the inlet of the molten salt steam generation system is determined by referring to the first opening step change setting logic. That is, for valves with a nominal diameter of DN50-DN100, the rated opening is selected as 5%-8%, and for valves with a nominal diameter greater than DN100, the rated opening is selected as 8%-10%, to ensure that the identification conditions of the two types of transfer functions are consistent.

[0062] Before applying a step change, the system should maintain stable operation for at least 30 minutes. The stability criteria are: molten salt temperature fluctuation at the inlet of the cryogenic molten salt tank ≤ ±1℃, molten salt pressure fluctuation at the outlet of the high-temperature molten salt pump ≤ ±0.1MPa, steam-water pressure fluctuation at the preheater outlet ≤ ±0.05MPa, and steam-water temperature fluctuation ≤ ±2℃. At this time, the baseline parameters should be recorded, including the initial value of the molten salt temperature at the inlet of the cryogenic molten salt tank T0 and the initial value of the molten salt pressure at the outlet of the high-temperature molten salt pump P. p0 Initial valve opening θ 02 and preheater outlet steam-water parameters P q0 T q0 .

[0063] After applying a step change, collect data on the temperature-related changes of the molten salt at the inlet of the cryogenic molten salt storage tank at a sampling frequency of 15Hz. The collection time continues until the temperature fluctuation is ≤±0.2℃ for 10 consecutive seconds, ensuring coverage from the initial value T0 to the new steady-state value T. ss The complete process. Extracting the temperature response delay time τ. dt heating rate (T) r For the 10%-90% temperature change time, ΔT=T ss -T0), peak temperature T p Overshoot σ T % and new steady-state value T ss This forms a dynamic temperature response curve.

[0064] The correction of the molten salt pressure at the outlet of the high-temperature molten salt pump is performed using the same method as described above, based on the pipeline resistance formula ΔP=λ×(L / D)×(ρv). 2 / 2) Calculate the theoretical value of pressure loss ΔP(t), and then pass it through P pcorr (t)=P p The corrected data is obtained by subtracting ΔP(t) from the output (t), thus eliminating the interference from pipeline resistance.

[0065] Based on the second step change in opening Δθ2=θ 12 -θ 02 Temperature-related change data T(t) and pressure correction data P pcorr (t), and a transfer function model is constructed using the system identification method. First, it is assumed to be a first-order inertial plus pure time-delay model. , with P pcorr (t) represents the input u T T(t) and T(t) are the outputs y T (t), after being discretized according to a 15Hz sampling period, the discretization parameter a is solved by the least squares method. T b T By working backwards, we can obtain K. T τ T T T Initial values ​​are then iteratively optimized using gradient descent (learning rate η). T =0.001, iteration limit 1000 times), until the sum of squared residuals S T <10 -5 .

[0066] Through Mean Absolute Error (MAE) T = Root mean square error Verify the fit. If MAE T ℃ or RMSE T The temperature response exhibits characteristics such as multiple peaks and oscillating decay, and is therefore upgraded to a second-order model. After discretization, the initial parameter values ​​are solved using the least squares method, and then optimized using a genetic algorithm (population size 50, 200 iterations, crossover probability 0.8, mutation probability 0.05, with RMSE... T (For the fitness function).

[0067] Finally, the frequency response is analyzed using Bode plots, and the amplitude-frequency error δA is required. T ≤3dB, phase frequency error , and MAE T ℃, RMSE T ℃, goodness of fit ≥95%, determine the inlet molten salt temperature transfer function of the cryogenic molten salt storage tank corresponding to the electric regulating valve.

[0068] Step 430: Determine the bivariate nonlinear coupling model between the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank based on the cross-influence coefficient and transfer function.

[0069] Next, based on the obtained cross-influence coefficients and two types of transfer functions, and combined with the heat exchange logic of the molten salt steam generation system, a basic correlation framework between variables is established, with changes in molten salt flow distribution and heat exchange load as the core inputs, and changes in superheater outlet steam pressure and low-temperature molten salt inlet molten salt temperature as the core outputs. The quantitative influence parameters of flow distribution on the core outputs are extracted using the two types of transfer functions and integrated into the framework to form a preliminary quantitative correlation model. Then, the cross-influence coefficients are incorporated to quantify the mutual interference between output parameters. A nonlinear compensation mechanism is constructed to optimize the model based on real-time operating parameters. Finally, each parameter is optimized through multi-condition real-time parameter sample verification, enabling the model to accurately indicate the dynamic correlation patterns and mutual influence amplitudes of the core variables.

[0070] In one specific implementation, based on the heat exchange principle of the molten salt steam generation system, the key input and output variables affecting the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank during system operation are determined. The input variables are defined as the change in molten salt flow distribution ΔQ (calculated by combining the opening changes of two types of electric regulating valves with pipeline flow characteristics) and the change in heat exchange load ΔL (calculated using the heat balance equation based on the inlet and outlet temperatures, pressures, and flow rates of the preheater and evaporator). The output variables are defined as the change in superheater outlet steam pressure ΔP and the change in cryogenic molten salt inlet temperature ΔT. Based on the preliminary interaction between the input and output variables, a linear correlation equation is constructed: ΔP = k P1 ΔQ+k P2 ΔL, ΔT = k T1ΔQ+k T2 ΔL, where k P1 k P2 These are the correlation coefficients, k, for the changes in molten salt flow rate distribution and heat exchange load on the changes in superheater outlet steam pressure. T1 k T2 These are the correlation coefficients between the changes in molten salt flow rate distribution and the changes in heat exchange load on the changes in the inlet molten salt temperature of the cryogenic molten salt storage tank, respectively.

[0071] Subsequently, initial values ​​of correlation coefficients were extracted from the transfer functions corresponding to the two types of electrically controlled valves. For the superheater outlet steam pressure transfer function corresponding to the opening disturbance of the molten salt electrically controlled valve at the inlet of the molten salt steam generation system... The gain K reflects the intensity of the influence of valve opening disturbance on the superheater outlet steam pressure. Combining the correspondence between valve opening and molten salt flow distribution (calibrated through pipeline flow characteristic curves), the initial value k of the correlation coefficient between the change in molten salt flow distribution and the superheater outlet steam pressure is extracted. P10 =K×k Q (k) Q (This is the conversion coefficient between valve opening and molten salt flow rate). Similarly, the gain K is extracted from the molten salt temperature transfer function at the inlet of the low-temperature molten salt tank corresponding to the disturbance of the opening of the electrically controlled regulating valve in the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet. T By combining the conversion relationship between valve opening and molten salt flow distribution, the initial value k of the correlation coefficient between the change in molten salt flow distribution and the inlet molten salt temperature of the cryogenic molten salt storage tank is obtained. T10 =K T ×k Q . K P10 k T10 Substitute the values ​​into the preliminary linear correlation equation, and simultaneously set the initial value k of the correlation coefficient corresponding to the change in heat transfer load. P20 =0.1、k T20 =0.05 (set based on experience from similar systems, and subsequently corrected through optimization and iteration), laying the foundation for the basic parameter framework of the equation.

[0072] Next, the previously calculated cross-influence coefficient CI was used... PT (Cross-influence coefficient of superheater outlet steam pressure on inlet molten salt temperature of cryogenic molten salt storage tank) and CI TP The cross-influence coefficient of the inlet molten salt temperature of the cryogenic molten salt storage tank on the outlet steam pressure of the superheater is used as a quantification factor for the coupling effect between output variables. A preliminary linear correlation equation is introduced to form a linear coupling equation containing coupling terms: ΔP=k P1 ΔQ+k P2 ΔL+CI TP ΔT, ΔT=k T1 ΔQ+k T2 ΔL+CIPT ΔP. This equation intuitively reflects the mutual interference relationship between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank through coupling terms, enabling the model to initially reflect the coupling characteristics between variables.

[0073] Then, the high-temperature molten salt pump outlet molten salt pressure P was combined with the real-time operating parameters. p Preheater outlet steam-water pressure P q This study analyzes the nonlinear factors in the system operation process. The system nonlinearity mainly originates from the variation of pipe friction coefficient with molten salt flow velocity and the fluctuation of heat exchange efficiency with temperature difference. These factors are significantly correlated with the molten salt pressure at the outlet of the high-temperature molten salt pump and the steam-water pressure at the outlet of the preheater. Based on multiple sets of real-time operating data, a nonlinear correction function is established using a polynomial fitting method: the nonlinear correction function f for the superheater outlet steam pressure is... P (P p ,P q )=a1P p 2 +b1P p +c1P q +d1, the nonlinear correction function f for the inlet molten salt temperature of the cryogenic molten salt storage tank. T (P p ,P q )=a2P p 2 +b2P p +c2P q +d2, where a1, b1, c1, d1, a2, b2, c2, and d2 are fitting coefficients. Integrating the above nonlinear correction function as a nonlinear correction term into the linear coupling equation, we obtain: ΔP = k P1 ΔQ+k P2 ΔL+CI TP ΔT+f P (P p ,P q ), ΔT=k T1 ΔQ+k T2 ΔL+CI PT ΔP+f T (P p ,P q This compensates for the shortcomings of linear models in describing the nonlinear characteristics of the system and improves the adaptability of the model.

[0074] Finally, using multiple sets of real-time operating parameter samples (no fewer than 50 samples, covering different molten salt flow distributions and different heat exchange load conditions), the gradient descent method was employed to analyze the correlation coefficient k in the linear coupling equation. P1 , kP2 k T1 k T2Coupling factor CI PT CI TP The nonlinear correction function parameters a1, b1, c1, d1, a2, b2, c2, and d2 are used for iterative optimization. The iteration learning rate is set to 0.001, and the maximum number of iterations is 2000. During each iteration, the change in superheater outlet steam pressure ΔP output by the equation is calculated. calc ΔT, the change in molten salt temperature at the inlet of the low-temperature molten salt storage tank calc Compared with the actual monitored value ΔP meas ΔT meas error The error is gradually reduced by adjusting the parameter values ​​using the gradient descent algorithm. When the iteration reaches e... P <0.01MPa and e T When the temperature drops below 0.3℃ (the threshold is determined based on the system control accuracy requirements), iteration stops, ultimately forming a bivariate nonlinear coupled model. This model can comprehensively and accurately indicate the dynamic correlation and mutual influence amplitude between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank under operating conditions of varying molten salt flow distribution and heat exchange load, providing reliable model support for subsequent decoupling matrix construction.

[0075] Step 440: Construct the decoupling matrix based on the bivariate nonlinear coupling model.

[0076] Based on the established bivariate nonlinear coupling model, the coupling correlation information between the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank is extracted, and the decoupling compensation coefficient is derived. At the same time, the independent effects of changes in molten salt flow distribution and heat exchange load on the two types of output parameters are analyzed, and the corresponding independent influence weights are obtained through standardization. The decoupling compensation coefficient and the two types of independent influence weights are used as core elements to construct a decoupling matrix. The cross interference of the two types of output parameters is separated through matrix linear transformation, and the matrix can be synchronously iteratively adjusted with the operating condition update of the bivariate nonlinear coupling model parameters to ensure reliable support for the independent and accurate adjustment of core parameters under different operating conditions.

[0077] In one specific implementation, the mathematical structure of the bivariate nonlinear coupling model is analyzed, and the core correlation parameter reflecting the coupling effect of the two types of output parameters is extracted, namely the cross-influence coefficient CI of the superheater outlet steam pressure on the inlet molten salt temperature of the low-temperature molten salt storage tank. PT The cross-influence coefficient CI of the inlet molten salt temperature of the low-temperature molten salt storage tank on the outlet steam pressure of the superheater. TP Based on these two coupling parameters, using the formula... Calculate the decoupling compensation coefficient, where K comp,PT To compensate for the cross-interference of temperature with pressure, K comp,TPThis is a compensation coefficient to counteract the cross-interference of pressure and temperature. The sign of this coefficient is opposite to that of the coupling correlation parameter, indicating the direction of the cross-interference. Its magnitude is positively correlated with the coupling strength, ensuring that the compensation effect accurately matches the interference amplitude.

[0078] Next, the independent influence weights of molten salt flow distribution changes on the two types of output parameters are determined. The independent action coefficient k of molten salt flow distribution changes on the superheater outlet steam pressure is extracted from the bivariate nonlinear coupling model. P1 The independent action coefficient k for the inlet molten salt temperature of the cryogenic molten salt storage tank T1 The independent influence weights, W, are calculated through normalization. Q,P = W Q,T = W Q,P W represents the weight of the independent impact of changes in molten salt flow distribution on the superheater outlet steam pressure. Q,T The weights represent the independent impact of changes in molten salt flow distribution on the inlet temperature of the cryogenic molten salt storage tank. After normalization, the sum of the squares of the two weights is 1, ensuring that the weights accurately reflect the relative strength of the effect of changes in molten salt flow distribution on each output parameter.

[0079] Subsequently, following the same logic, the independent influence weights of heat load changes on the two types of output parameters were determined. The independent action coefficient k of the heat load change on the superheater outlet steam pressure was extracted from the model. P2 The independent action coefficient k for the inlet molten salt temperature of the cryogenic molten salt storage tank T2 Through the normalization formula W L,P = W L,T = Calculate the weights, where W L,P W represents the independent impact weight of heat exchange load changes on superheater outlet steam pressure. L,T The weights represent the independent impact of heat load changes on the inlet molten salt temperature of the cryogenic molten salt storage tank. The weight values ​​range from [0,1], with larger values ​​indicating a more significant independent effect of heat load changes on the corresponding output parameters.

[0080] Finally, based on the mathematical principles and matrix construction rules of system decoupling, a dynamic decoupling matrix is ​​constructed. The decoupling matrix is ​​a 2×2 matrix, and its elements consist of decoupling compensation coefficients and weights of two independent influence classes, specifically in the form: D = The matrix consists of two rows: the first row corresponds to the decoupling adjustment coefficient for the superheater outlet steam pressure, and the second row corresponds to the decoupling adjustment coefficient for the molten salt temperature at the inlet of the cryogenic molten salt storage tank. This dynamic decoupling matrix is ​​applied to the input variable vector [ΔQ, ΔL] through a linear transformation. TThis method decomposes the coupled input variables into independent components acting independently on the superheater outlet steam pressure and the cryogenic molten salt inlet molten salt tank temperature, thereby completely separating the cross-interference between the two types of output parameters. This ensures that subsequent adjustments to either parameter will not affect the stable operation of the other, laying the foundation for precise and independent control of core parameters. The dynamic characteristics of the decoupling matrix are reflected in the fact that when the parameters of the bivariate nonlinear coupling model are updated as the system operating conditions change, the elements of the decoupling matrix are synchronously iteratively adjusted, ensuring good decoupling performance under different operating conditions.

[0081] Step 450: Based on the deviation and rate of change of the superheater outlet steam pressure, and combined with the characteristics of the decoupled superheater outlet steam pressure independently responding to the molten salt flow distribution regulation, determine the opening degree of the molten salt electric regulating valve at the inlet of the molten salt steam generation system.

[0082] Combining the characteristics of the decoupled superheater outlet steam pressure independently responding to the molten salt flow distribution regulation, the deviation of the superheater outlet steam pressure (the difference between the set value and the real-time monitoring value) and the deviation change rate (the ratio of the difference in deviation between adjacent sampling periods to the sampling period) are first calculated. Then, based on the real-time valve opening change and the response characteristic parameters of pressure with opening change, the pressure deviation correction amount is determined to predict the deviation impact of opening adjustment. By analyzing the correlation between deviation and deviation change rate and the requirements for stable system operation, the control parameters are optimized. The deviation correction amount is integrated into the control logic and the relevant parameters are adjusted to balance response speed and anti-interference capability. Finally, the target opening of the molten salt electric regulating valve at the inlet of the molten salt steam generation system is calculated by substituting the relevant parameters. The target opening is limited to 0%-100% of the valve's rated opening to ensure that the pressure quickly and stably approaches the set value.

[0083] In one specific embodiment, the real-time opening change Δθ of the electric regulating valve at the inlet of the molten salt steam generation system is obtained. P (The difference between the current opening degree and the opening degree of the previous sampling period), combined with the response characteristic parameter of the superheater outlet steam pressure changing with the opening degree after decoupling: response rate v P (Ratio of pressure change to opening change), response amplitude A P (The maximum pressure change corresponding to a unit change in opening degree), expressed by the formula Δe P =k corr ×Δθ P ×v P ×A P Calculate the correction amount for the superheater outlet steam pressure deviation. Where k corr The correction coefficient is determined based on the system steady-state error test, and its value ranges from 0.05 to 0.1 to ensure that the correction amount can compensate for the predicted pressure deviation caused by the change in opening degree.

[0084] Next, the deviation of the superheater outlet steam pressure, e=P, is calculated. set -P meas (P) set For the pressure setpoint, P meas (Real-time monitoring values) and deviation change rate (e) k e represents the current cycle deviation. k-1 T represents the deviation from the previous cycle. s The sampling period is 1 / 15s. Based on system operation requirements, a preset fuzzy subset is defined: the deviation e is divided into 7 subsets: "Negative Large (NB), Negative Medium (NM), Negative Small (NS), Zero (ZO), Positive Small (PS), Positive Medium (PM), Positive Large (PB)," corresponding to a quantization range of [-0.3, 0.3] MPa; the deviation change rate... Similarly, it is divided into 7 fuzzy subsets, with a quantization range of [-0.1, 0.1] MPa / s. Combining the correlation between pressure deviation and the rate of change of deviation, and the system's stable operation requirements (overshoot ≤ 5%, settling time ≤ 5s), fuzzy inference rules are formulated, such as "If e is PB and..." If NB is used, then the switching gain adjustment is PB. "If e is ZO and..." If ZO is true, then the switching gain adjustment is ZO. A total of 49 inference rules form a complete rule base. The quantized values ​​of the current deviation and the rate of change of deviation are input into the fuzzy inference system, and the switching gain adjustment ΔK of sliding mode control is obtained by mapping through the Mamdani fuzzy inference method (minimum-maximum synthesis method, centroid method for defuzzification). s .

[0085] Then, the correction for the superheater outlet steam pressure deviation is incorporated into the reaching law expression of the sliding mode control. An exponential reaching law is selected. (Where s is the switching function, ε>0 is the approach velocity parameter, k>0 is the decay coefficient, and sgn(·) is the sign function), the expression for the approach law after incorporating the correction is: Combined with the switching gain adjustment ΔK s Adjust sliding mode control parameters: Set the switching function to s=e+c∫edt (c>0 is the integral coefficient), based on ΔK s Adjust the switching gain K s =K s0 +ΔK s (K) s0 The initial switching gain (determined based on the system's maximum disturbance test) is used, while simultaneously adjusting the approach velocity parameter ε = ε0 + 0.5 |ΔK. s | (ε0 is the initial approach velocity parameter) to obtain the adjusted sliding mode control approach law and switching function, ensuring that the system has both fast response and anti-interference capability.

[0086] Finally, the real-time opening change Δθ of the electric regulating valve at the inlet of the molten salt steam generation system is measured. P The response rate v of the superheater outlet steam pressure after decoupling as a function of the opening degree. P and response amplitude A P Deviation e and rate of change of deviation Substitute the adjusted sliding mode control reaching law and switching function. Then, using the formula u=K... s sgn(s)+ eq Calculate the control output u (where eq The equivalent control term is derived from the system dynamics equations. Then, through the opening conversion formula θ target =θ curr +u×K θ The target valve opening is calculated. Where θ curr K represents the current valve opening. θ To control the conversion coefficient between output and opening degree, it is calibrated based on the valve flow characteristic curve. The target opening degree needs to be limited to 0%-100% of the valve's rated opening degree. If the calculated result exceeds this range, the boundary value is taken as the final opening degree to ensure safe valve operation and ultimately achieve rapid and stable superheater outlet steam pressure approaching the set value.

[0087] Step 460: Based on the feedback of the deviation of the inlet molten salt temperature of the low-temperature molten salt storage tank, and combined with the characteristics of the independent response of the inlet molten salt temperature of the decoupled low-temperature molten salt storage tank to the molten salt flow distribution regulation, determine the opening degree of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet.

[0088] Combining the characteristics of the decoupled cryogenic molten salt tank inlet temperature independently responding to the molten salt flow distribution regulation, the deviation of the cryogenic molten salt tank inlet temperature (the difference between the set value and the real-time monitoring value) and the deviation change rate (the ratio of the difference in deviation between adjacent sampling periods to the sampling period) are first calculated. Then, based on the real-time valve opening change and the response characteristic parameters of temperature with opening change, the temperature deviation correction amount is determined to predict the impact of opening adjustment on temperature deviation. Combining the system's anti-condensation operation requirements, the correlation between deviation and deviation change rate is analyzed, the control parameters are optimized and integrated into the control logic, and the control model is dynamically corrected to ensure the control accuracy and stability. Finally, the target opening of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is calculated by substituting relevant parameters. The target opening is limited to 0%-100% of the valve's rated opening to ensure that the molten salt temperature is stably maintained within the set range to avoid the risk of solidification.

[0089] In one specific implementation, the real-time opening change Δθ of the electric regulating valve in the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is obtained. T(The difference between the current opening degree and the opening degree of the previous sampling period), combined with the response characteristic parameters of the inlet molten salt temperature of the decoupled cryogenic molten salt storage tank as a function of the opening degree. Response sensitivity ST (the ratio of temperature change to opening degree change), steady-state regulation amplitude A. TT (The final steady-state temperature change corresponding to a unit change in opening degree), expressed by the formula Δe T =k Tcorr ×Δθ T ×S T ×A TT Calculate the correction amount for the inlet molten salt temperature deviation in the cryogenic molten salt storage tank. Where k... Tcorr The temperature correction coefficient is determined based on the system temperature steady-state error test, and its value ranges from 0.03 to 0.08, ensuring that the correction amount can accurately predict the temperature deviation caused by changes in the opening degree.

[0090] Next, the deviation e of the inlet molten salt temperature of the cryogenic molten salt storage tank is calculated. T =T set -T meas (T) set The temperature setting, such as 190℃ for ternary Hitec molten salt, can be adjusted according to the type of molten salt; T meas (Real-time monitoring value) and the rate of change of deviation (e) Tk eT(k-1) represents the current cycle deviation, and T represents the deviation of the previous cycle. s The sampling period is 1 / 15s. Based on the system's anti-condensation operation requirements (temperature fluctuation ≤ ±1℃, adjustment time ≤ 8s), a preset fuzzy subset is defined: deviation e. T Divided into 7 subsets: "Negative Large (NB), Negative Medium (NM), Negative Small (NS), Zero (ZO), Positive Small (PS), Positive Medium (PM), Positive Large (PB)," with a quantization range of [-5, 5]℃; deviation change rate T Similarly, it is divided into 7 fuzzy subsets, with a quantization range of [-1, 1]℃ / s. Fuzzy inference rules are formulated based on the correlation between temperature deviation and the rate of change of deviation, for example, "If e..." T For NB and T If e is PB, then the proportional coefficient adjustment is PB, the integral coefficient adjustment is PM, and the derivative coefficient adjustment is PS. T is ZO and T "If ZO is true, then the adjustment amounts for all three types of coefficients are ZO", forming a complete rule base of 49 rules. The quantized values ​​of the current deviation and the rate of deviation change are input into the fuzzy inference system. Using the Mamdani fuzzy inference method (minimum-maximum synthesis method, centroid method for defuzzification), the proportional coefficient adjustment amount ΔK for adaptive PID control is mapped to obtain the result. pIntegral coefficient adjustment ΔK i Differential coefficient adjustment ΔK d .

[0091] Then, the correction for the molten salt temperature deviation at the inlet of the cryogenic molten salt storage tank is incorporated into the deviation control equation of the PID control. The conventional PID deviation control equation is as follows: After incorporating the correction amount, adjust to The PID control parameters are dynamically corrected by combining the adjustment amount obtained from fuzzy inference: initial parameter K. p0 K i0 K d0 Determined based on system step response experiments (usually K) p0 =2.0-3.5, K i0 =0.1-0.3, K d0 =0.5-1.2), the corrected parameter is K p =K p0 +ΔK p K i =K i0 +ΔK i K d =K d0 +ΔK d At the same time, the parameter boundaries (K) are limited. p ∈[1.0,5.0]、K i ∈[0.05,0.5]、K d (∈[0.2,2.0]), to avoid parameter overflow leading to instability, and finally obtain the adjusted adaptive PID control model.

[0092] Finally, the real-time opening change Δθ of the electric regulating valve in the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is measured. T The response sensitivity S of the inlet molten salt temperature of the decoupled cryogenic molten salt storage tank to changes in opening degree. T and steady-state adjustment amplitude A TT , deviation e T and the rate of change of deviation T Substitute the adjusted adaptive PID control model into the control output u to calculate the control output u. T Using the opening conversion formula θT target =θT curr +u T ×K θT The target valve opening is obtained, where θ Tcurr K represents the current valve opening. θTTo control the conversion coefficient between output and opening degree, it is calibrated based on the valve flow characteristic curve. The target opening degree needs to be limited to 0%-100% of the valve's rated opening degree. If it exceeds this range, the boundary value is taken to ensure the safe operation of the valve. Ultimately, this ensures that the inlet molten salt temperature of the cryogenic molten salt storage tank is stably maintained within the set range, guaranteeing the safe circulation of molten salt.

[0093] After achieving precise control of the core parameters on the molten salt side, in order to further ensure the stable operation of the feedwater side of the molten salt steam generation system and avoid the risk of preheater feedwater vaporization, this application formulates a special control strategy for the feedwater system, as follows.

[0094] First, define the rated water level range of the deaerator (determined based on the deaerator design parameters, typically 30%-70% of its total volume), the design feedwater pressure threshold of the preheater (set based on the pressure resistance rating of the preheater material and heat exchange requirements, generally 1.2-2.5 MPa), and the real-time heating steam load demand (collected via a steam flow sensor in the steam header). With the constraints of maintaining the deaerator water level within the rated range, ensuring the preheater feedwater pressure does not exceed the design threshold, and achieving a balance between heating steam load supply and demand, establish a multivariate coupled equation: H set1 H set2 These are the upper and lower limits of the deaerator's rated water level, Q. fw Q is the water supply flow rate. steam H represents the steam output flow rate. deo P represents the real-time water level of the deaerator. pre,min P pre,max The upper and lower limits of the preheater's designed feedwater pressure are respectively P pump ΔP is the outlet pressure of the electric feedwater pump. pipe For the pressure loss of the water supply pipeline, Q load For real-time heating steam load, k1-k6 are correlation coefficients (determined based on fitting of system steady-state test data). The optimal initial solution of this multivariate coupled equation is solved using the Newton-Raphson method, with the feedwater flow rate Q corresponding to the optimal initial solution as the given value. fw,opt Based on the flow characteristic curve of the feedwater electric regulating valve (calibrated through valve step test), the initial opening θ of the feedwater electric regulating valve in the molten salt steam generation system is determined. fw,init This ensures that the initial opening can meet the basic water supply requirements under the current operating conditions.

[0095] Next, real-time pressure data P is collected through the preheater outlet feedwater pressure sensor. pre,out Based on the relationship between water saturation temperature and pressure (based on the IAPWS-IF97 formula for water and steam properties), calculate the water saturation temperature T corresponding to this pressure. sat =f(P pre,out Simultaneously, the real-time temperature T is collected through the preheater outlet feedwater temperature sensor.pre,out Calculate the difference ΔT between the two. sat =T sat -T pre,out This difference is used to determine whether there is a risk of vaporization in the water supply (usually requiring a temperature of ℃).

[0096] Then, select the difference ΔT under different operating conditions from the historical operating data. sat Water flow rate Q fw The opening degree θ of the electric regulating valve for feedwater in the molten salt steam generation system fw and heating load data Q load As a sample set (with no fewer than 100 samples), a nonlinear mapping model was established using the Support Vector Machine (SVM) algorithm. Water flow rate, valve opening, and heating load were used as input vectors, and the difference ΔTsat was used as the output vector. The kernel function parameters of the SVM were optimized using a grid search method (radial basis function was selected, the penalty coefficient C ranged from 1 to 10, and the kernel function parameter γ ranged from 0.1 to 1), and the nonlinear mapping model ΔT was obtained through training. sat =f(Q fw ,θ fw Q load This model can predict the difference ΔT under different operating conditions based on the current input parameters. sat By observing the changing trends, we can anticipate the risks of vaporization in advance.

[0097] Finally, set the preset safety difference ΔT safe (Based on the system's anti-vaporization requirements, generally taken as 5-8℃), calculate the current difference ΔT. sat Deviation from the preset safety difference e ΔT =ΔT safe -ΔT sat Based on the changing trend predicted by the nonlinear mapping model (e.g., increasing the deviation weight if the predicted difference will continue to decrease), the proportional coefficient K of the PID control is determined. p Integral coefficient K i Differential coefficient K d Among them, the proportionality coefficient K p Dynamically adjust based on the magnitude of the deviation (the larger the deviation, the greater K). p The larger the value (ranging from 0.8 to 3.0), the larger the integral coefficient K becomes. i Used to eliminate static error (value range 0.05-0.3), differential coefficient K d Adjust according to the trend (the steeper the trend, the better). d The larger the value (ranging from 0.2 to 1.5), the better. Substituting the determined proportional, integral, and derivative coefficients into the PID control algorithm, the target opening θ of the electric regulating valve for the feedwater from the preheater outlet to the deaerator is calculated. refluxThe target opening degree needs to be limited to the range of 0%-100%. By adjusting the valve opening degree, the return feed water flow rate is changed, so that the difference ΔT sat The water level is kept stable near the preset safety difference, effectively avoiding the risk of preheater feedwater vaporization and ensuring the stable operation of the feedwater system.

[0098] In summary, the molten salt steam generation system control method of this application collects real-time operating parameters from all dimensions, accurately constructs cross-influence coefficients and transfer functions, and then forms a bivariate nonlinear coupling model and builds a dynamic decoupling matrix. This effectively separates the cross-interference between the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank. Combined with the deviation characteristics of core parameters and the independent response law after decoupling, the valve opening control logic is optimized in a targeted manner. At the same time, the risk of preheater feedwater vaporization is avoided through a special control strategy for the feedwater system. This achieves precise and independent control of key parameters on the molten salt side and the steam-water side, ensuring the stable operation of the system under different operating conditions. It also improves heat exchange efficiency and energy utilization, effectively avoids safety hazards such as molten salt solidification and equipment corrosion, extends the service life of the system, and adapts to diverse heating load demands.

[0099] It is understood that, in order to achieve the functions in the above embodiments, the computer device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0100] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0101] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A control method for a molten salt steam generation system, characterized in that, The molten salt steam generation system includes: an electric regulating valve for the molten salt inlet of the molten salt steam generation system, and an electric regulating valve for the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet. The method includes: Collect real-time operating parameters of the molten salt steam generation system; Based on the real-time operating parameters, determine the cross-influence coefficient between the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank, the transfer function of the superheater outlet steam pressure corresponding to the opening disturbance of the electric regulating valve of the molten salt inlet of the molten salt steam generation system, and the transfer function of the inlet molten salt temperature of the low-temperature molten salt storage tank corresponding to the opening disturbance of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet molten salt pipeline. The bivariate nonlinear coupling model between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank is determined based on the cross-influence coefficient and the transfer function. The bivariate nonlinear coupling model is used to indicate the dynamic correlation and mutual influence amplitude between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank under the conditions of molten salt flow distribution and heat exchange load change. A decoupling matrix is ​​constructed based on the bivariate nonlinear coupling model. The decoupling matrix is ​​used to separate the cross-interference between the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank. Based on the deviation and rate of change of the superheater outlet steam pressure, and combined with the characteristics of the decoupled superheater outlet steam pressure independently responding to the molten salt flow distribution regulation, the opening degree of the inlet molten salt electric regulating valve of the molten salt steam generation system is determined. Based on the feedback of the deviation of the molten salt temperature at the inlet of the low-temperature molten salt storage tank, and combined with the characteristic of the independent response of the molten salt flow distribution adjustment at the inlet of the low-temperature molten salt storage tank after decoupling, the opening degree of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is determined.

2. The method according to claim 1, characterized in that, Based on the aforementioned real-time operating parameters, the cross-influence coefficient between the superheater outlet steam pressure and the inlet molten salt temperature of the cryogenic molten salt storage tank, the transfer function of the superheater outlet steam pressure corresponding to the opening disturbance of the electric regulating valve of the molten salt inlet of the molten salt steam generation system, and the transfer function of the inlet molten salt temperature of the cryogenic molten salt storage tank corresponding to the opening disturbance of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet molten salt pipeline are determined, including: Based on the superheater outlet steam pressure, the low-temperature molten salt inlet molten salt temperature, the real-time opening degree of the electric regulating valve of the molten salt inlet of the molten salt steam generation system and the electric regulating valve of the high-temperature molten salt pump to the preheater outlet molten salt pipeline, as well as the preheater outlet steam and water pressure and preheater outlet steam and water temperature, determine the cross-influence coefficient between the superheater outlet steam pressure and the low-temperature molten salt inlet molten salt temperature. Based on the first opening step change of the inlet molten salt electric regulating valve of the molten salt steam generation system, the superheater outlet steam pressure response data corresponding to the first opening step change, and the molten salt pressure correction data at the outlet of the high-temperature molten salt pump, the transfer function of the superheater outlet steam pressure corresponding to the opening disturbance of the inlet molten salt electric regulating valve of the molten salt steam generation system is determined. Based on the second opening step change of the electric regulating valve of the high-temperature molten salt pump to the preheater outlet molten salt pipeline, the correlation change data of the low-temperature molten salt inlet molten salt temperature corresponding to the second opening step change, and the high-temperature molten salt pump outlet molten salt pressure correction data, the transfer function of the low-temperature molten salt inlet molten salt temperature corresponding to the opening disturbance of the electric regulating valve of the high-temperature molten salt pump to the preheater outlet molten salt pipeline is determined.

3. The method according to claim 2, characterized in that, Based on the cross-influence coefficient and the transfer function, a bivariate nonlinear coupling model is determined between the superheater outlet steam pressure and the cryogenic molten salt inlet temperature, including: Based on the heat exchange mechanism of the molten salt steam generation system, the changes in molten salt flow distribution and heat exchange load are used as input variables, and the changes in superheater outlet steam pressure and low-temperature molten salt inlet molten salt temperature are used as output variables. Preliminary linear correlation equations between the input variables and each output variable are constructed. The initial value of the correlation coefficient between the change in molten salt flow distribution and the superheater outlet steam pressure is extracted from the transfer function of the superheater outlet steam pressure corresponding to the disturbance of the opening of the electric regulating valve of the molten salt inlet ... The cross-influence coefficient is used as a quantification factor for the coupling effect between output variables and introduced into the preliminary linear correlation equation to form a linear coupling equation containing coupling terms. Based on the high-temperature molten salt pump outlet molten salt pressure and preheater outlet steam-water pressure in the real-time operating parameters, a nonlinear correction function is established, and the nonlinear correction function is incorporated into the linear coupling equation as a nonlinear correction term. The correlation coefficients, coupling factors, and nonlinear correction function parameters in the linear coupling equation are iteratively optimized using the real-time operating parameter samples until the errors between the superheater outlet steam pressure change and the low-temperature molten salt inlet molten salt temperature change output by the linear coupling equation and the actual monitored values ​​are all less than a set threshold, thus forming the bivariate nonlinear coupling model.

4. The method according to claim 3, characterized in that, The dynamic decoupling matrix is ​​constructed based on the bivariate nonlinear coupling model, including: Extract the coupling correlation parameters between the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank in the bivariate nonlinear coupling model, and determine the decoupling compensation coefficient based on the coupling correlation parameters; Based on the independent action coefficients of the molten salt flow distribution change on the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank in the bivariate nonlinear coupling model, the independent influence weights of the molten salt flow distribution change on the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank are determined. Based on the independent action coefficients of heat load change on superheater outlet steam pressure and low-temperature molten salt inlet temperature in the bivariate nonlinear coupling model, the independent influence weights of heat load change on superheater outlet steam pressure and low-temperature molten salt inlet temperature are determined. The decoupling compensation coefficient and the independent influence weights of changes in molten salt flow distribution and heat exchange load on the superheater outlet steam pressure and the inlet molten salt temperature of the low-temperature molten salt storage tank are used as matrix elements to construct a dynamic decoupling matrix.

5. The method according to claim 4, characterized in that, Based on the deviation and rate of change of the superheater outlet steam pressure, and considering the independent response of the decoupled superheater outlet steam pressure to molten salt flow regulation, the opening degree of the inlet molten salt electric regulating valve of the molten salt steam generation system is determined, including: Based on the real-time opening change of the electric regulating valve at the inlet of the molten salt steam generation system, the response rate and response amplitude of the superheater outlet steam pressure after decoupling as the opening changes, the correction amount for the superheater outlet steam pressure deviation is determined. Based on the numerical range of the deviation and the rate of change of deviation, a preset fuzzy subset is divided. Combining the correlation between pressure deviation and the rate of change of deviation and the requirements for stable operation, fuzzy inference rules are determined. The switching gain adjustment amount of sliding mode control is obtained by mapping through the fuzzy inference rules. The superheater outlet steam pressure deviation correction is incorporated into the sliding mode control approach law expression, and the switching function parameters and approach speed parameters of the sliding mode control are adjusted in combination with the switching gain adjustment to obtain the adjusted sliding mode control approach law and switching function. The opening degree of the molten salt electric regulating valve at the inlet of the molten salt steam generation system is calculated by substituting the real-time opening change of the molten salt electric regulating valve at the inlet of the molten salt steam generation system, the response rate and response amplitude of the superheater outlet steam pressure after decoupling as the opening degree changes, the deviation and the deviation change rate, into the adjusted sliding mode control approach law and switching function.

6. The method according to claim 4, characterized in that, Based on the feedback of the deviation in the inlet molten salt temperature of the low-temperature molten salt storage tank, and combined with the characteristic of the decoupled low-temperature molten salt storage tank inlet molten salt temperature independently responding to the molten salt flow distribution adjustment, the opening degree of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is determined, including: Based on the real-time opening change of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet, the response sensitivity of the inlet molten salt temperature of the decoupled low-temperature molten salt storage tank with the opening change, and the steady-state regulating amplitude, the correction amount of the inlet molten salt temperature deviation of the low-temperature molten salt storage tank is determined. Based on the numerical range of the deviation and the rate of change of the deviation, a preset fuzzy subset is divided. Combining the correlation between temperature deviation and the rate of change of the deviation and the system's anti-condensation operation requirements, fuzzy inference rules are determined. The proportional coefficient, integral coefficient, and derivative coefficient adjustment amounts of the adaptive PID control are obtained by mapping the fuzzy inference rules. The deviation correction amount of the molten salt temperature at the inlet of the low-temperature molten salt storage tank is incorporated into the deviation adjustment equation of the PID control, and the PID control parameters are dynamically corrected in combination with the coefficient adjustment amount to obtain the adjusted adaptive PID control model. The opening degree of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is calculated by substituting the real-time opening degree change of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet, the response sensitivity and steady-state regulation amplitude of the molten salt temperature at the inlet of the decoupled low-temperature molten salt storage tank as the opening degree changes, the deviation and the rate of deviation change, into the adjusted adaptive PID control model.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: Based on the rated water level range of the deaerator, the design feedwater pressure threshold of the preheater, and the real-time heating steam load demand, a multivariate coupled equation is established, the optimal initial solution of the multivariate coupled equation is solved, and the opening degree of the feedwater electric regulating valve of the molten salt steam generation system is determined based on the optimal initial solution. Calculate the water saturation temperature corresponding to the preheater outlet water pressure and the difference between the water saturation temperature and the preheater outlet water temperature based on the collected preheater outlet water pressure. Based on the difference, water flow rate, opening degree of the electric regulating valve of the molten salt steam generation system, and heating load data, a nonlinear mapping relationship model is established. The nonlinear mapping relationship model is used to predict the changing trend of the difference under different operating conditions. Based on the deviation between the difference and the preset safety difference and the changing trend predicted by the nonlinear mapping relationship model, the proportional coefficient, integral coefficient, and derivative coefficient are determined. The opening degree of the electric regulating valve for water supply from the preheater outlet to the deaerator is determined based on the proportional coefficient, integral coefficient, and differential coefficient.

8. A molten salt steam generation system, characterized in that, The molten salt steam generation system includes: a high-temperature molten salt pump, a superheater, a preheater, an electric regulating valve for the molten salt inlet of the molten salt steam generation system, and an electric regulating valve for the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet. One end of the electric regulating valve at the inlet of the molten salt steam generation system is sealed to the outlet of the high-temperature molten salt pump, and the other end is sealed to the molten salt inlet of the superheater. One end of the electric regulating valve of the molten salt pipeline from the high-temperature molten salt pump to the preheater outlet is sealed to the outlet of the high-temperature molten salt pump, and the other end is sealed to the molten salt return pipeline on the outlet side of the preheater.

9. The molten salt steam generating system according to claim 8, characterized in that, The molten salt steam generation system also includes a deaerator, an electric regulating valve for the molten salt steam generation system feedwater, and an electric regulating valve for the feedwater from the preheater outlet to the deaerator. One end of the electric regulating valve for the molten salt steam generation system is sealed to the outlet of the deaerator, and the other end is sealed to the feedwater inlet of the preheater. One end of the electric regulating valve for water supply to the deaerator from the preheater outlet is sealed to the outlet of the preheater, and the other end is sealed to the inlet of the deaerator.

10. The molten salt steam generating system according to claim 8 or 9, characterized in that, The molten salt steam generation system also includes a steam supply manifold, an electric regulating valve for steam from the superheater to the steam supply manifold, and an electric regulating valve for desuperheating water. One end of the electric steam regulating valve from the superheater to the steam supply manifold is sealed to the steam outlet of the superheater, and the other end is sealed to the inlet of the steam supply manifold. One end of the electric regulating valve for desuperheating water is sealed to an external desuperheating water source, and the other end is sealed to the steam pipeline from the superheater to the steam supply manifold.

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