A control method, apparatus, equipment and medium for a molten salt thermal storage system

Abstract

This application relates to the fields of power generation technology and control technology. It discloses a control method, apparatus, equipment, and medium for a molten salt thermal storage system. The method includes: assembling the current state information of the molten salt thermal storage system from the current salt flow rate, current steam pressure, current molten salt level, and current pipe wall temperature; transmitting the current state data, target state data, and constraints to a predictive controller; processing the current state data, target state data, and constraints by the predictive controller to obtain multiple control sequences; selecting the control sequence with the smallest fluctuation coefficient as the target control sequence; and adjusting the current speed of the molten salt pump to the target speed, the current opening degree of the feedwater valve to the target opening degree, the current opening degree of the mixing valve to the target opening degree, and the current opening degree of the steam bypass valve to the target opening degree. This application can improve the efficiency of obtaining the target control sequence.

Description

Technical Field

[0001] This application relates to the fields of power generation technology and control technology, and in particular to a control method, device, equipment and medium for a molten salt thermal storage system. Background Technology

[0002] During operation, molten salt thermal storage systems experience thermal stress fluctuations due to frequent changes in molten salt temperature and uneven heating across the storage container. These fluctuations negatively impact the stability and safety of the system. To mitigate these fluctuations, it is necessary to obtain the target control sequence for the molten salt thermal storage system.

[0003] However, the process of obtaining the target control sequence for existing molten salt thermal energy storage systems is cumbersome, which hinders the improvement of acquisition efficiency. This is because current technologies primarily rely on manual acquisition methods to obtain the target control sequence for molten salt thermal energy storage systems. Manual acquisition consumes significant human and time resources, increasing the acquisition time and thus hindering efficiency. Summary of the Invention

[0004] This application provides a control method, apparatus, equipment, and medium for a molten salt thermal storage system to solve the technical problem that the acquisition process of the target control sequence in the existing molten salt thermal storage system is cumbersome and not conducive to improving the acquisition efficiency of the target control sequence.

[0005] In a first aspect, embodiments of this application provide a control method for a molten salt thermal storage system, applied to a control device for the molten salt thermal storage system. The molten salt thermal storage system includes a molten salt pump, a feedwater valve, a mixing valve, and a steam bypass valve. The control method includes:

[0006] Acquire the collected data of the molten salt thermal storage system, and obtain the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature from the collected data. Combine the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature to form the current status information of the molten salt thermal storage system. Obtain the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature from the configuration file, and combine the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature to form the target status information of the molten salt thermal storage system.

[0007] The current state data, target state data, and constraints are transmitted to the predictive controller. The predictive controller processes the current state data, target state data, and constraints to obtain multiple control sequences. A simulation model of the molten salt thermal storage system is then obtained. Each control sequence is run through the simulation model of the molten salt thermal storage system to obtain the running information of each control sequence.

[0008] In the operation information of each control sequence, the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence are obtained.

[0009] Using the objective function of the molten salt thermal storage system, the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence are processed to obtain the fluctuation coefficient corresponding to each control sequence.

[0010] The control sequence with the smallest fluctuation coefficient is selected as the target control sequence for the molten salt thermal storage system. Based on the target control sequence, the current speed of the molten salt pump is adjusted to the target speed of the molten salt pump, the current opening degree of the feedwater valve is adjusted to the target opening degree of the feedwater valve, the current opening degree of the mixing valve is adjusted to the target opening degree of the mixing valve, and the current opening degree of the steam bypass valve is adjusted to the target opening degree of the steam bypass valve.

[0011] In one possible implementation of the first aspect, the step of acquiring the collected data of the molten salt thermal storage system, obtaining the current salt flow rate, current steam pressure, current molten salt level, and current pipe wall temperature from the collected data, and combining the current salt flow rate, current steam pressure, current molten salt level, and current pipe wall temperature to form the current state information of the molten salt thermal storage system, and obtaining the target salt flow rate, target steam pressure, target molten salt level, and target pipe wall temperature from the configuration file, and combining the target salt flow rate, target steam pressure, target molten salt level, and target pipe wall temperature to form the target state information of the molten salt thermal storage system, includes:

[0012] The operating parameters of the molten salt pump, the feedwater valve, the mixing valve, and the steam bypass valve are collected through a distributed sensor network to obtain the collected data of the molten salt thermal storage system.

[0013] The current salt flow rate, current steam pressure, current molten salt level, and current pipe wall temperature are obtained from the collected data. These data are then used to construct the current state information of the molten salt thermal storage system. Target salt flow rate, target steam pressure, target molten salt level, and target pipe wall temperature are obtained from the configuration file. These data are then used to construct the target state information of the molten salt thermal storage system. In one possible implementation of the first aspect, selecting the control sequence with the smallest fluctuation coefficient as the target control sequence for the molten salt thermal storage system, and adjusting the current speed of the molten salt pump to the target speed of the molten salt pump, adjusting the current opening degree of the feedwater valve to the target opening degree of the feedwater valve, adjusting the current opening degree of the mixing valve to the target opening degree of the mixing valve, and adjusting the current opening degree of the steam bypass valve to the target opening degree of the steam bypass valve, includes:

[0014] The control sequence with the smallest fluctuation coefficient is selected as the target control sequence of the molten salt thermal storage system. The salt flow control increment of the first control step in the target control sequence is input to the actuator of the molten salt pump. The first control command output by the actuator of the molten salt pump is obtained. The speed increment in the first control command is used to adjust the current speed of the molten salt pump to the target speed of the molten salt pump.

[0015] The water flow control increment of the first control step in the target control sequence is input to the actuator of the water supply valve. The second control command output by the actuator of the water supply valve is obtained. The opening adjustment amount in the second control command is used to adjust the current opening of the water supply valve to the target opening of the water supply valve.

[0016] The mixing medium flow control increment of the first control step in the target control sequence is input to the actuator of the mixing valve. The third control command output by the actuator of the mixing valve is obtained. The opening adjustment amount in the third control command is used to adjust the current opening of the mixing valve to the target opening of the mixing valve.

[0017] The steam flow control increment of the first control step in the target control sequence is input to the actuator of the steam bypass valve. The fourth control command output by the actuator of the steam bypass valve is obtained. The opening adjustment amount in the fourth control command is used to adjust the current opening of the steam bypass valve to the target opening of the steam bypass valve.

[0018] In one possible implementation of the first aspect, the objective function of the molten salt thermal storage system is defined as follows:

[0019] ;

[0020] For the first The volatility coefficient corresponding to the first control sequence; The larger the fluctuation coefficient corresponding to the first control sequence, the more likely the thermal storage system is using the first control sequence. The greater the thermal stress fluctuation during the first control sequence, the greater the thermal stress fluctuation during the second control sequence. The smaller the fluctuation coefficient corresponding to the first control sequence, the more likely the thermal storage system is using the first control sequence. The smaller the thermal stress fluctuation during each control sequence;

[0021] To predict the total number of steps; To control the total number of steps;

[0022] For the first In the control sequence, the first... The steam parameter deviation corresponding to each prediction step is the difference between the predicted value and the set value of the steam parameter. for The square of the L2 norm, where steam parameters are steam pressure or steam temperature;

[0023] For the first In the control sequence, the first... The wall temperature gradient corresponding to each prediction step; for The square of the L2 norm;

[0024] For the first In the control sequence, the first... The steam drum water level deviation corresponds to each prediction step. The steam drum water level deviation is the difference between the predicted value of the steam drum water level and the set value of the steam drum water level. for The square of the L2 norm;

[0025] For the first In each control sequence indivual Incremental combination, for The square of the L2 norm;

[0026] include , , and ;

[0027] For the first In the control sequence, the first... The salt flow control increment for each control step is a dynamic adjustment amount that increases or decreases based on the current molten salt flow rate.

[0028] For the first In the control sequence, the first... The water flow control increment is a dynamic adjustment amount that increases or decreases based on the current water flow.

[0029] For the first In the control sequence, the first... The mixed medium flow control increment is a dynamic adjustment amount that increases or decreases based on the current mixed medium flow rate.

[0030] For the first In the control sequence, the first... The steam flow control increment for each control step is an adjustment amount that is dynamically increased or decreased based on the current steam flow rate.

[0031] In one possible implementation of the first aspect, the constraints are that the wall temperature gradient is no greater than 80 Kelvin, the steam drum water level deviation is within 40 mm, and the steam dryness fraction is greater than or equal to 0.99.

[0032] In one possible implementation of the first aspect, the wall temperature gradient includes a radial temperature gradient of the wall surface.

[0033] In one possible implementation of the first aspect, the current molten salt level is the current height of the molten salt in the molten salt tank, and the target molten salt level is the desired height of the molten salt in the molten salt tank;

[0034] The current steam pressure is the actual steam pressure value collected in real time by the pressure sensor at the evaporator outlet, while the target steam pressure is the preset steam pressure value that needs to be maintained at the evaporator outlet.

[0035] The current salt flow rate is the actual flow rate of molten salt in the molten salt conveying pipeline, and the target salt flow rate is the preset flow rate that the molten salt in the molten salt conveying pipeline needs to maintain.

[0036] The current pipe wall temperature is the actual temperature value of the pipe wall at the current moment, and the target pipe wall temperature is the preset temperature value that the pipe wall needs to maintain.

[0037] Secondly, embodiments of this application provide a control device for a molten salt thermal storage system, applicable to the control equipment of a molten salt thermal storage system. The molten salt thermal storage system includes a molten salt pump, a feedwater valve, a mixing valve, and a steam bypass valve, comprising:

[0038] The first acquisition module is used to acquire the collected data of the molten salt thermal storage system, and to acquire the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature from the collected data. The current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature are combined to form the current status information of the molten salt thermal storage system. The target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature are acquired from the configuration file, and the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature are combined to form the target status information of the molten salt thermal storage system.

[0039] The second acquisition module is used to transmit the current state data, target state data and constraints to the predictive controller. The predictive controller processes the current state data, target state data and constraints to obtain multiple control sequences, acquires the simulation model of the molten salt thermal storage system, runs each control sequence through the simulation model of the molten salt thermal storage system, and obtains the operation information of each control sequence.

[0040] The third acquisition module is used to acquire, in the operation information of each control sequence, the steam parameter deviation, the wall temperature gradient, the steam drum water level deviation, and the incremental combination corresponding to each control step in each control sequence.

[0041] The fourth acquisition module is used to process the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence using the objective function of the molten salt thermal storage system, so as to obtain the fluctuation coefficient corresponding to each control sequence.

[0042] The control module is used to select the control sequence with the smallest fluctuation coefficient as the target control sequence of the molten salt thermal storage system. According to the target control sequence, the current speed of the molten salt pump is adjusted to the target speed of the molten salt pump, the current opening degree of the feedwater valve is adjusted to the target opening degree of the feedwater valve, the current opening degree of the mixing valve is adjusted to the target opening degree of the mixing valve, and the current opening degree of the steam bypass valve is adjusted to the target opening degree of the steam bypass valve.

[0043] Thirdly, embodiments of this application provide a control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the control method described in the first aspect above.

[0044] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the control method described in the first aspect above.

[0045] Fifthly, embodiments of this application provide a computer program product that, when run on a control device, causes the control device to execute the control method described in the first aspect.

[0046] The beneficial effects of this application's embodiments are twofold. Firstly, by selecting the control sequence with the smallest fluctuation coefficient as the target control sequence for the molten salt thermal storage system, the current speed of the molten salt pump is adjusted to its target speed, the current opening degree of the feedwater valve is adjusted to its target opening degree, the current opening degree of the mixing valve is adjusted to its target opening degree, and the current opening degree of the steam bypass valve is adjusted to its target opening degree. This reduces the acquisition time of the target control sequence for the molten salt thermal storage system, thus improving the acquisition efficiency. Secondly, the larger the fluctuation coefficient corresponding to the control sequence, the greater the thermal stress fluctuation when the thermal storage system uses the control sequence; conversely, the smaller the fluctuation coefficient, the smaller the thermal stress fluctuation. Selecting the control sequence with the smallest fluctuation coefficient as the target control sequence for the molten salt thermal storage system reduces thermal stress fluctuations when the system uses the target control sequence. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a diagram illustrating an application scenario of the control method provided in the embodiments of this application.

[0049] Figure 2 This is a flowchart illustrating the control method provided in an embodiment of this application;

[0050] Figure 3 A flowchart illustrating the implementation of S201 provided in this application embodiment;

[0051] Figure 4 A schematic block diagram of a control device provided in an embodiment of this application;

[0052] Figure 5 A schematic diagram of the structure of the control device provided in the embodiment of this application. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0054] The control method provided in this application can be applied to control devices such as mobile phones, tablets, wearable devices, in-vehicle devices, augmented reality (AR) / virtual reality (VR) devices, laptops, ultra-mobile personal computers (UMPCs), netbooks, and personal digital assistants (PDAs). This application does not impose any restrictions on the specific type of control device.

[0055] Please see Figure 1 , Figure 1 The application scenario diagram of the control method provided in the embodiments of this application is described in detail below:

[0056] The molten salt thermal storage system includes a molten salt pump, a feed water valve, a mixing valve, and a steam bypass valve. The control equipment is connected to the molten salt pump, the feed water valve, the mixing valve, and the steam bypass valve.

[0057] The working process of the molten salt thermal energy storage system of this application is as follows: Molten salt is used as the heat transfer and storage medium. Solar energy is captured and heated by a concentrating solar collector. The heated molten salt is stored in a thermal storage tank. When there is a demand for power generation, the heated molten salt is transported to the heat exchange island by a molten salt pump. Water controlled by the evaporator and the feed water valve is vaporized. After the vaporized steam humidity is reduced by the mixing valve, it is heated by the heat exchanger to form high-temperature and high-pressure steam. The steam bypass valve controls the steam flow direction in real time, and the steam drives the power generation equipment to generate electricity.

[0058] As the core power source, the molten salt pump can match the heat collection power under different light conditions and form a closed-loop feedback with the steam pressure to avoid the decrease in heat exchange efficiency due to fluctuations in molten salt supply.

[0059] The water supply valve achieves dynamic matching of water supply flow, ensuring a stable ratio of steam and water mixture in the evaporator and preventing dry burning due to insufficient water supply or water carryover in the steam due to excessive water supply.

[0060] The mixing valve regulates the humidity of saturated steam and superheated steam, strictly controlling the steam humidity below the target value, effectively protecting the turbine blades from water erosion damage.

[0061] The steam bypass valve responds quickly to sudden load changes by directly introducing excess steam into the condenser, thus smoothing out steam pressure peaks and providing buffer time for molten salt pump flow adjustment, preventing the system from triggering protection shutdowns due to parameter over-limits.

[0062] In this embodiment, the control device is connected to the molten salt pump, the feed water valve, the mixing valve, and the steam bypass valve simultaneously, which can achieve coordinated optimization of the molten salt pump, the feed water valve, the mixing valve, and the steam bypass valve.

[0063] Please see Figure 2 , Figure 2 This is a flowchart illustrating the control method provided in the embodiments of this application. This method can be applied to the control equipment of a molten salt thermal storage system, which includes a molten salt pump, a water supply valve, a mixing valve, and a steam bypass valve.

[0064] like Figure 2 As shown, the control method provided in this application includes the following steps, which are detailed below:

[0065] S201, acquire the collected data of the molten salt thermal storage system, obtain the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature from the collected data, and combine the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature to form the current status information of the molten salt thermal storage system; acquire the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature from the configuration file, and combine the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature to form the target status information of the molten salt thermal storage system;

[0066] The current molten salt level is the current height of the molten salt in the molten salt storage tank, and the target molten salt level is the desired height of the molten salt in the molten salt storage tank.

[0067] The current steam pressure is the actual steam pressure value collected in real time by the pressure sensor at the evaporator outlet, while the target steam pressure is the preset steam pressure value that needs to be maintained at the evaporator outlet.

[0068] The current salt flow rate is the actual flow rate of molten salt in the molten salt conveying pipeline, and the target salt flow rate is the preset flow rate that the molten salt in the molten salt conveying pipeline needs to maintain.

[0069] The current pipe wall temperature is the actual temperature value of the pipe wall at the current moment, and the target pipe wall temperature is the preset temperature value that the pipe wall needs to maintain.

[0070] S202, transmit the current state data, target state data and constraints to the predictive controller, process the current state data, target state data and constraints to obtain multiple control sequences, obtain the simulation model of the molten salt thermal storage system, run each control sequence through the simulation model of the molten salt thermal storage system, and obtain the operation information of each control sequence;

[0071] The constraints are: wall temperature gradient not greater than 80 Kelvin, steam drum water level deviation within 40 mm, and steam dryness fraction greater than or equal to 0.99.

[0072] Among them, the Model Predictive Control (MPC) is a control strategy based on dynamic models that combines optimization and real-time feedback.

[0073] Among these steps, obtaining a simulation model of the molten salt thermal energy storage system allows for the construction of a physical model. This model breaks down the complex molten salt thermal energy storage system into key components such as the molten salt tank, heat exchanger, and piping, clearly defining the function and structure of each component. After the physical model is built, specialized simulation software, based on its built-in mathematical algorithms and physical rules, transforms the physical model into a computable simulation model.

[0074] S203, in the operation information of each control sequence, obtain the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence.

[0075] Steam parameter deviation is the difference between the predicted value and the set value of the steam parameter.

[0076] The wall temperature gradient includes the radial temperature gradient of the wall surface.

[0077] The steam drum water level deviation is the difference between the predicted value of the steam drum water level and the set value of the steam drum water level.

[0078] S204 uses the objective function of the molten salt thermal storage system to process the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence, and obtains the fluctuation coefficient corresponding to each control sequence.

[0079] The objective function for the molten salt thermal energy storage system is defined as follows:

[0080] ;

[0081] For the first The volatility coefficient corresponding to the first control sequence; The larger the fluctuation coefficient corresponding to the first control sequence, the more likely the thermal storage system is using the first control sequence. The greater the thermal stress fluctuation during the first control sequence, the greater the thermal stress fluctuation during the second control sequence. The smaller the fluctuation coefficient corresponding to the first control sequence, the more likely the thermal storage system is using the first control sequence. The smaller the thermal stress fluctuation during each control sequence;

[0082] To predict the total number of steps; To control the total number of steps;

[0083] For the first In the control sequence, the first... The steam parameter deviation corresponding to each prediction step is the difference between the predicted value and the set value of the steam parameter. for The square of the L2 norm, where steam parameters are steam pressure or steam temperature;

[0084] For the first In the control sequence, the first... The wall temperature gradient corresponding to each prediction step; for The square of the L2 norm;

[0085] For the first In the control sequence, the first... The steam drum water level deviation corresponds to each prediction step. The steam drum water level deviation is the difference between the predicted value of the steam drum water level and the set value of the steam drum water level. for The square of the L2 norm;

[0086] For the first In each control sequence indivual Incremental combination, for The square of the L2 norm;

[0087] include , , and ;

[0088] ;

[0089] For the first In the control sequence, the first... The salt flow control increment for each control step is a dynamic adjustment amount that increases or decreases based on the current molten salt flow rate.

[0090] For the first In the control sequence, the first... The water flow control increment is a dynamic adjustment amount that increases or decreases based on the current water flow.

[0091] For the first In the control sequence, the first... The mixed medium flow control increment is a dynamic adjustment amount that increases or decreases based on the current mixed medium flow rate.

[0092] For the first In the control sequence, the first... The steam flow control increment for each control step is an adjustment amount that is dynamically increased or decreased based on the current steam flow rate.

[0093] Preferably, The value ranges from 60 to 180 steps. The value ranges from 10 to 30 steps.

[0094] S205, select the control sequence with the smallest fluctuation coefficient as the target control sequence of the molten salt thermal storage system. According to the target control sequence, adjust the current speed of the molten salt pump to the target speed of the molten salt pump, adjust the current opening degree of the feed water valve to the target opening degree of the feed water valve, adjust the current opening degree of the mixing valve to the target opening degree of the mixing valve, and adjust the current opening degree of the steam bypass valve to the target opening degree of the steam bypass valve.

[0095] The target control sequence implements soft control over the molten salt pump, feedwater valve, mixing valve, and steam bypass valve, which can reduce thermal stress fluctuations and reduce mechanical wear of the molten salt pump, feedwater valve, mixing valve, and steam bypass valve.

[0096] For ease of explanation, the following example is provided:

[0097] For example, during startup, the molten salt thermal storage system performs preheating according to the target control sequence. By controlling the molten salt circulation flow, the tank wall temperature is slowly raised to 250°C to avoid thermal stress shock. Then, it enters the constant temperature and uniform temperature stage, maintaining thermal circulation for 15 to 30 minutes, using the molten salt flow characteristics to eliminate uneven temperature field distribution. After the temperature field on the salt side is uniform, the temperature rise alignment program is started, coordinating with the water side to gradually preheat and match pressure parameters until the grid connection conditions are met. Finally, the load is gradually increased according to the preset ramp rate to achieve stable grid connection and power generation.

[0098] The selection of the control sequence with the smallest fluctuation coefficient as the target control sequence for the molten salt thermal storage system, and the adjustment of the current speed of the molten salt pump to the target speed of the molten salt pump, the adjustment of the current opening degree of the feedwater valve to the target opening degree of the feedwater valve, the adjustment of the current opening degree of the mixing valve to the target opening degree of the mixing valve, and the adjustment of the current opening degree of the steam bypass valve to the target opening degree of the steam bypass valve, includes:

[0099] The control sequence with the smallest fluctuation coefficient is selected as the target control sequence of the molten salt thermal storage system. The salt flow control increment of the first control step in the target control sequence is input to the actuator of the molten salt pump. The first control command output by the actuator of the molten salt pump is obtained. The speed increment in the first control command is used to adjust the current speed of the molten salt pump to the target speed of the molten salt pump.

[0100] The water flow control increment of the first control step in the target control sequence is input to the actuator of the water supply valve. The second control command output by the actuator of the water supply valve is obtained. The opening adjustment amount in the second control command is used to adjust the current opening of the water supply valve to the target opening of the water supply valve.

[0101] The mixing medium flow control increment of the first control step in the target control sequence is input to the actuator of the mixing valve. The third control command output by the actuator of the mixing valve is obtained. The opening adjustment amount in the third control command is used to adjust the current opening of the mixing valve to the target opening of the mixing valve.

[0102] The steam flow control increment of the first control step in the target control sequence is input to the actuator of the steam bypass valve. The fourth control command output by the actuator of the steam bypass valve is obtained. The opening adjustment amount in the fourth control command is used to adjust the current opening of the steam bypass valve to the target opening of the steam bypass valve.

[0103] By using the first control command, the molten salt pump can achieve smooth speed regulation, avoid bearing wear and shaft vibration caused by start-up and shutdown shocks and overload operation, and ensure stable flow output;

[0104] By using the opening adjustment amount in the second control command, the current opening of the water supply valve is adjusted to the target opening of the water supply valve, which can reduce the hard contact loss between the valve core and the valve seat of the water supply valve and the impact erosion of the medium, and improve the sealing reliability of the water supply valve.

[0105] By using the opening adjustment amount in the third control command to adjust the current opening of the mixing valve to the target opening of the mixing valve, the hard contact loss between the valve core and the valve seat and the impact erosion of the medium can be reduced, thereby improving the sealing reliability of the mixing valve.

[0106] The opening adjustment amount in the fourth control command is used to adjust the current opening of the steam bypass valve to the target opening of the steam bypass valve, so as to avoid valve erosion and noise caused by sudden changes in steam pressure and ensure system pressure balance.

[0107] The beneficial effects of this application's embodiments are twofold. Firstly, by selecting the control sequence with the smallest fluctuation coefficient as the target control sequence for the molten salt thermal storage system, the current speed of the molten salt pump is adjusted to its target speed, the current opening degree of the feedwater valve is adjusted to its target opening degree, the current opening degree of the mixing valve is adjusted to its target opening degree, and the current opening degree of the steam bypass valve is adjusted to its target opening degree. This reduces the acquisition time of the target control sequence for the molten salt thermal storage system, thus improving the acquisition efficiency. Secondly, the larger the fluctuation coefficient corresponding to the control sequence, the greater the thermal stress fluctuation when the thermal storage system uses the control sequence; conversely, the smaller the fluctuation coefficient, the smaller the thermal stress fluctuation. Selecting the control sequence with the smallest fluctuation coefficient as the target control sequence for the molten salt thermal storage system reduces thermal stress fluctuations when the system uses the target control sequence.

[0108] Please see Figure 3 , Figure 3 The implementation flowchart of S201 provided in the embodiments of this application is described in detail below:

[0109] S301 collects the operating parameters of the molten salt pump, the feed water valve, the mixing valve, and the steam bypass valve through a distributed sensor network to obtain the collected data of the molten salt thermal storage system.

[0110] S302: Obtain the current salt flow rate, current steam pressure, current molten salt level, and current pipe wall temperature from the collected data, and combine the current salt flow rate, current steam pressure, current molten salt level, and current pipe wall temperature to form the current status information of the molten salt thermal storage system. Obtain the target salt flow rate, target steam pressure, target molten salt level, and target pipe wall temperature from the configuration file, and combine the target salt flow rate, target steam pressure, target molten salt level, and target pipe wall temperature to form the target status information of the molten salt thermal storage system.

[0111] In this embodiment, the operating parameters of the molten salt pump, the feed water valve, the mixing valve, and the steam bypass valve are collected through a distributed sensor network, eliminating the time lag and subjective error of manual inspection and realizing real-time monitoring of the entire process.

[0112] For the control method described in the above embodiments, please refer to [link / reference]. Figure 4 , Figure 4 This is a schematic block diagram of the control device provided in the embodiments of this application. Figure 4 The control device 400 shown can be applied to, for example Figure 1 The control device shown in the application scenario diagram will be used as an example below to illustrate the application scenario. Figure 4 The control device 400 shown will be described in detail. The control device 400 may include a first acquisition module 401, a second acquisition module 402, a third acquisition module 403, a fourth acquisition module 404, and a control module 405.

[0113] The first acquisition module 401 is used to acquire the collected data of the molten salt thermal storage system, and to acquire the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature from the collected data. The current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature are combined to form the current status information of the molten salt thermal storage system. The target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature are acquired from the configuration file, and the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature are combined to form the target status information of the molten salt thermal storage system.

[0114] The second acquisition module 402 is used to transmit the current state data, target state data and constraints to the predictive controller, process the current state data, target state data and constraints through the predictive controller to obtain multiple control sequences, acquire the simulation model of the molten salt thermal storage system, run each control sequence through the simulation model of the molten salt thermal storage system, and obtain the running information of each control sequence.

[0115] The third acquisition module 403 is used to acquire, in the operation information of each control sequence, the steam parameter deviation corresponding to each prediction step in each control sequence, the wall temperature gradient corresponding to each prediction step in each control sequence, the steam drum water level deviation corresponding to each prediction step in each control sequence, and the incremental combination corresponding to each control step in each control sequence.

[0116] The fourth acquisition module 404 is used to process the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence using the objective function of the molten salt thermal storage system, so as to obtain the fluctuation coefficient corresponding to each control sequence.

[0117] The control module 405 is used to select the control sequence with the smallest fluctuation coefficient as the target control sequence of the molten salt thermal storage system. According to the target control sequence, the current speed of the molten salt pump is adjusted to the target speed of the molten salt pump, the current opening degree of the feed water valve is adjusted to the target opening degree of the feed water valve, the current opening degree of the mixing valve is adjusted to the target opening degree of the mixing valve, and the current opening degree of the steam bypass valve is adjusted to the target opening degree of the steam bypass valve.

[0118] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0119] The beneficial effects of this application embodiment are twofold. Firstly, it reduces the acquisition time of the target control sequence for the molten salt thermal storage system, which is conducive to improving the acquisition efficiency of the target control sequence for the molten salt thermal storage system. Secondly, the larger the fluctuation coefficient corresponding to the control sequence, the greater the thermal stress fluctuation when the thermal storage system adopts the control sequence; the smaller the fluctuation coefficient corresponding to the control sequence, the smaller the thermal stress fluctuation when the thermal storage system adopts the control sequence. Selecting the control sequence with the smallest fluctuation coefficient as the target control sequence for the molten salt thermal storage system can reduce thermal stress fluctuation when the thermal storage system adopts the target control sequence.

[0120] Please see Figure 5 , Figure 5 A schematic diagram of the structure of the control device provided in the embodiment of this application.

[0121] like Figure 5 As shown, Figure 5 The control device 2 includes: at least one processor 20, a memory 21, and a computer program 22 stored in the memory 21 and executable on the at least one processor 20, wherein the processor 20 executes the computer program 22 to implement the steps in any of the above method embodiments.

[0122] The control device 2 may include, but is not limited to, a processor 20 and a memory 21. Those skilled in the art will understand that... Figure 5 This is merely an example of control device 2 and does not constitute a limitation on control device 2. It may include more or fewer components than shown in the figure, or combine certain components, or different components, such as input / output devices, network access devices, etc.

[0123] The processor 20 is used to run a computer program 22 stored in the memory 21, and performs the following steps when executing the computer program 22:

[0124] Acquire the collected data of the molten salt thermal storage system, and obtain the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature from the collected data. Combine the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature to form the current status information of the molten salt thermal storage system. Obtain the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature from the configuration file, and combine the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature to form the target status information of the molten salt thermal storage system.

[0125] The current state data, target state data, and constraints are transmitted to the predictive controller. The predictive controller processes the current state data, target state data, and constraints to obtain multiple control sequences. A simulation model of the molten salt thermal storage system is then obtained. Each control sequence is run through the simulation model of the molten salt thermal storage system to obtain the running information of each control sequence.

[0126] In the operation information of each control sequence, the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence are obtained.

[0127] Using the objective function of the molten salt thermal storage system, the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence are processed to obtain the fluctuation coefficient corresponding to each control sequence.

[0128] The control sequence with the smallest fluctuation coefficient is selected as the target control sequence for the molten salt thermal storage system. Based on the target control sequence, the current speed of the molten salt pump is adjusted to the target speed of the molten salt pump, the current opening degree of the feedwater valve is adjusted to the target opening degree of the feedwater valve, the current opening degree of the mixing valve is adjusted to the target opening degree of the mixing valve, and the current opening degree of the steam bypass valve is adjusted to the target opening degree of the steam bypass valve.

[0129] The processor 20 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors, or application-specific integrated circuits.

[0130] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A control method for a molten salt thermal storage system, characterized in that, A control device for a molten salt thermal storage system, the molten salt thermal storage system including a molten salt pump, a feedwater valve, a mixing valve, and a steam bypass valve, wherein the control method includes: Acquire the collected data of the molten salt thermal storage system, and obtain the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature from the collected data. Combine the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature to form the current status information of the molten salt thermal storage system. Obtain the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature from the configuration file, and combine the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature to form the target status information of the molten salt thermal storage system. The current state data, target state data, and constraints are transmitted to the predictive controller. The predictive controller processes the current state data, target state data, and constraints to obtain multiple control sequences. A simulation model of the molten salt thermal storage system is then obtained. Each control sequence is run through the simulation model of the molten salt thermal storage system to obtain the running information of each control sequence. In the operation information of each control sequence, the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence are obtained. Using the objective function of the molten salt thermal storage system, the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence are processed to obtain the fluctuation coefficient corresponding to each control sequence. The control sequence with the smallest fluctuation coefficient is selected as the target control sequence for the molten salt thermal storage system. Based on the target control sequence, the current speed of the molten salt pump is adjusted to the target speed of the molten salt pump, the current opening degree of the feedwater valve is adjusted to the target opening degree of the feedwater valve, the current opening degree of the mixing valve is adjusted to the target opening degree of the mixing valve, and the current opening degree of the steam bypass valve is adjusted to the target opening degree of the steam bypass valve.

2. The control method according to claim 1, characterized in that, include: The operating parameters of the molten salt pump, the feedwater valve, the mixing valve, and the steam bypass valve are collected through a distributed sensor network to obtain the collected data of the molten salt thermal storage system. The current salt flow rate, current steam pressure, current molten salt level, and current pipe wall temperature are obtained from the collected data. These data are then combined to form the current status information of the molten salt thermal storage system. The target salt flow rate, target steam pressure, target molten salt level, and target pipe wall temperature are obtained from the configuration file. These data are then combined to form the target status information of the molten salt thermal storage system.

3. The control method according to claim 1, characterized in that, include: The control sequence with the smallest fluctuation coefficient is selected as the target control sequence of the molten salt thermal storage system. The salt flow control increment of the first control step in the target control sequence is input to the actuator of the molten salt pump. The first control command output by the actuator of the molten salt pump is obtained. The speed increment in the first control command is used to adjust the current speed of the molten salt pump to the target speed of the molten salt pump. The water flow control increment of the first control step in the target control sequence is input to the actuator of the water supply valve. The second control command output by the actuator of the water supply valve is obtained. The opening adjustment amount in the second control command is used to adjust the current opening of the water supply valve to the target opening of the water supply valve. The mixing medium flow control increment of the first control step in the target control sequence is input to the actuator of the mixing valve. The third control command output by the actuator of the mixing valve is obtained. The opening adjustment amount in the third control command is used to adjust the current opening of the mixing valve to the target opening of the mixing valve. The steam flow control increment of the first control step in the target control sequence is input to the actuator of the steam bypass valve. The fourth control command output by the actuator of the steam bypass valve is obtained. The opening adjustment amount in the fourth control command is used to adjust the current opening of the steam bypass valve to the target opening of the steam bypass valve.

4. The control method according to claim 1, characterized in that, The objective function for a molten salt thermal energy storage system is defined as follows: ； For the first The volatility coefficient corresponding to the first control sequence; The larger the fluctuation coefficient corresponding to the first control sequence, the more likely the thermal storage system is using the first control sequence. The greater the thermal stress fluctuation during the first control sequence, the greater the thermal stress fluctuation during the second control sequence. The smaller the fluctuation coefficient corresponding to the first control sequence, the more likely the thermal storage system is using the first control sequence. The smaller the thermal stress fluctuation during each control sequence; To predict the total number of steps; To control the total number of steps; For the first In the control sequence, the first... The steam parameter deviation corresponding to each prediction step is the difference between the predicted value and the set value of the steam parameter. for The square of the L2 norm, where steam parameters are steam pressure or steam temperature; For the first In the control sequence, the first... The wall temperature gradient corresponding to each prediction step; for The square of the L2 norm; For the first In the control sequence, the first... The steam drum water level deviation corresponds to each prediction step. The steam drum water level deviation is the difference between the predicted value of the steam drum water level and the set value of the steam drum water level. for The square of the L2 norm; For the first In each control sequence indivual Incremental combination, for The square of the L2 norm; include , , and ; For the first In the control sequence, the first... The salt flow control increment for each control step is a dynamic adjustment amount that increases or decreases based on the current molten salt flow rate. For the first In the control sequence, the first... The water flow control increment is a dynamic adjustment amount that increases or decreases based on the current water flow. For the first In the control sequence, the first... The mixed medium flow control increment is a dynamic adjustment amount that increases or decreases based on the current mixed medium flow rate. For the first In the control sequence, the first... The steam flow control increment for each control step is an adjustment amount that is dynamically increased or decreased based on the current steam flow rate.

5. The control method according to claim 1, characterized in that, The constraints are: wall temperature gradient not greater than 80 Kelvin, steam drum water level deviation within 40 mm, and steam dryness fraction greater than or equal to 0.

99.

6. The control method according to claim 1, characterized in that, The wall temperature gradient includes the radial temperature gradient of the wall surface.

7. The control method according to claim 1, characterized in that, The current molten salt level is the current height of the molten salt in the molten salt storage tank, and the target molten salt level is the desired height of the molten salt in the molten salt storage tank. The current steam pressure is the actual steam pressure value collected in real time by the pressure sensor at the evaporator outlet, while the target steam pressure is the preset steam pressure value that needs to be maintained at the evaporator outlet. The current salt flow rate is the actual flow rate of molten salt in the molten salt conveying pipeline, and the target salt flow rate is the preset flow rate that the molten salt in the molten salt conveying pipeline needs to maintain. The current pipe wall temperature is the actual temperature value of the pipe wall at the current moment, and the target pipe wall temperature is the preset temperature value that the pipe wall needs to maintain.

8. A control device for a molten salt thermal storage system based on the control method for a molten salt thermal storage system according to any one of claims 1 to 7, characterized in that, Control equipment used in molten salt thermal storage systems, which include molten salt pumps, feedwater valves, mixing valves, and steam bypass valves, including: The first acquisition module is used to acquire the collected data of the molten salt thermal storage system, and to acquire the current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature from the collected data. The current salt flow rate, current steam pressure, current molten salt level and current pipe wall temperature are combined to form the current status information of the molten salt thermal storage system. The target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature are acquired from the configuration file, and the target salt flow rate, target steam pressure, target molten salt level and target pipe wall temperature are combined to form the target status information of the molten salt thermal storage system. The second acquisition module is used to transmit the current state data, target state data and constraints to the predictive controller. The predictive controller processes the current state data, target state data and constraints to obtain multiple control sequences, acquires the simulation model of the molten salt thermal storage system, runs each control sequence through the simulation model of the molten salt thermal storage system, and obtains the operation information of each control sequence. The third acquisition module is used to acquire, in the operation information of each control sequence, the steam parameter deviation, the wall temperature gradient, the steam drum water level deviation, and the incremental combination corresponding to each control step in each control sequence. The fourth acquisition module is used to process the steam parameter deviation, wall temperature gradient, steam drum water level deviation, and incremental combination corresponding to each prediction step in each control sequence using the objective function of the molten salt thermal storage system, so as to obtain the fluctuation coefficient corresponding to each control sequence. The control module is used to select the control sequence with the smallest fluctuation coefficient as the target control sequence of the molten salt thermal storage system. According to the target control sequence, the current speed of the molten salt pump is adjusted to the target speed of the molten salt pump, the current opening degree of the feedwater valve is adjusted to the target opening degree of the feedwater valve, the current opening degree of the mixing valve is adjusted to the target opening degree of the mixing valve, and the current opening degree of the steam bypass valve is adjusted to the target opening degree of the steam bypass valve.

9. A control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the control method as described in any one of claims 1 to 7.

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