A method, system, and medium for deaerator water level control adapted to rapid load changes in thermal power units.

Abstract

This application relates to a deaerator water level control method, system, and medium adapted to rapid load changes in thermal power units. The method includes: with the deaerator water level control loop engaged, the deviation between the target load value and the actual unit load is calculated by the main loop PID1 controller to obtain the deaerator water level setpoint; the deaerator water level setpoint is sent to the secondary loop PID2 controller for water level tracking and adjustment; the deaerator water level regulating valve is in automatic mode, and the PID2 controller calculates the change in valve opening based on the change in the deaerator water level setpoint to control the condensate flow rate and adjust the extraction steam flow rate of each low-pressure heater, allowing the unit to briefly gain or release some energy, thus achieving rapid unit response to load changes. This application, by combining the deaerator water level regulating loop with the unit's coordinated control system, based on the condensate throttling principle, improves the unit's response rate in the initial stage of load changes, reduces the original unit's response delay, and decreases parameter fluctuations during load adjustment.

Description

Technical Field

[0001] This application relates to the field of thermal power unit control technology, and more specifically, to a deaerator water level control method, system and medium adapted to rapid load changes in thermal power units. Background Technology

[0002] New energy sources such as wind and solar power are heavily influenced by natural conditions and exhibit significant randomness. Large-scale grid connection can lead to insufficient adaptability in the power system's absorption capacity. To improve the regulation capacity of new energy sources, enhancing the flexibility of thermal power units is crucial. However, excessively high load variation rates in thermal power units can cause fluctuations in unit parameters. These fluctuations in main steam pressure and temperature, caused by inertial differences between the boiler and turbine sides, can severely impact unit safety. Methods such as condensate throttling, based on the comprehensive utilization of unit energy storage, are key to improving unit flexibility. Condensate throttling can change the unit load without affecting boiler-side parameters, avoiding the limitations imposed on flexibility by large inertia and delays on the boiler side.

[0003] Existing condensate throttling technologies mostly involve controlling the opening degree of the deaerator's water supply valve or the frequency of the condensate pump. However, since the main factors affecting unit safety during condensate throttling are the condenser and deaerator water levels, existing methods require setting a series of conditions for enabling and disabling condensate throttling control to ensure unit safety. Compared to the deaerator water level, the condenser water level generally fluctuates less and the condenser capacity is larger, so its impact on safety during condensate throttling is not significant. Summary of the Invention

[0004] The purpose of this application is to provide a deaerator water level control method, system, and medium adapted to rapid load changes in thermal power units. This improves the initial load response performance during load changes and reduces overshoot during load response adjustment, enabling the unit load to be adjusted to the target load command more quickly and stably. Addressing the problem of complex control loops in existing condensate throttling technologies, this invention designs a deaerator water level control method to achieve condensate throttling while ensuring the safety of unit operation.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] In a first aspect, embodiments of this application provide a deaerator water level control method adapted to rapid load changes in thermal power units, comprising the following specific steps:

[0007] With the deaerator water level control loop in operation, the deviation between the target load value and the actual load of the unit is calculated by the main loop PID1 controller to obtain the deaerator water level setpoint.

[0008] The deaerator water level setpoint is sent to the secondary loop PID2 controller for water level tracking and adjustment;

[0009] When the deaerator water level regulating valve is in automatic mode, the PID2 controller calculates the change in valve opening based on the change in the deaerator water level setpoint to control the condensate flow rate and adjust the steam extraction flow rate of each low-pressure heater so that the unit can briefly obtain or release some energy, thereby enabling the unit to respond quickly to load changes.

[0010] The deaerator water level control loop is designed with a dynamic feedforward based on load deviation and main steam pressure command parameters. When the unit receives a load change command, the main steam pressure setpoint is subtracted from the main steam pressure setpoint after multi-stage delay and speed limiting. After one first-stage delay, the result is multiplied by the set main steam pressure change rate to obtain the main steam pressure feedforward factor. The main steam pressure feedforward factor is multiplied by the load feedforward factor obtained from the deviation between the load target value and the actual load of the unit to form the dynamic feedforward. The dynamic feedforward acts on the secondary loop PID2 controller and is superimposed with the output of the PID2 controller to control the condensate flow rate.

[0011] With the deaerator water level control loop in operation, the deaerator water level setpoint is calculated by the PID1 controller, and the opening degree of the deaerator water level regulating valve is obtained by superimposing the output of the PID1 controller and the dynamic feedforward. The transfer function calculation formula is as follows:

[0012]

[0013]

[0014] In the formula Lv sp Lv(s) is the deaerator water level setpoint, and Lv(s) is the deaerator water level.

[0015] ΔP(s) represents the deviation between the target load value and the actual load of the unit;

[0016] K p1 K p2 These are the proportional gains of PID1 controller and PID2 controller, respectively.

[0017] T i1 T i2 These are the integral times of PID1 controller and PID2 controller, respectively;

[0018] OP(s) is the deaerator water level regulating valve opening command;

[0019] FF(s) is a dynamic feedforward.

[0020] In the deaerator water level control loop, the PID1 controller and PID2 controller are tuned according to the cascade system. The principle of the PID2 controller is to quickly reach the water level setpoint without overshooting the deaerator water level, and it is tuned using lambda. The tuning principle of the PID1 controller is to not exceed the action speed of the inner loop, and the dynamic feedforward amplitude is limited to ±15.

[0021] The deaerator water level control method adapted to rapid load changes in thermal power units also includes designing exit conditions for the deaerator water level setting loop, specifically,

[0022] (1) Main steam pressure deviation of the unit is less than 0.5 MPa and unit load deviation is less than 1 MW, and these conditions are maintained. The deaerator water level setting circuit is then disconnected.

[0023] (2) When the deaerator water level regulating valve is switched to manual mode, the deaerator water level setting circuit is exited.

[0024] (3) When the condenser water level exceeds the set range, exit the deaerator water level setting circuit;

[0025] After the load regulation process is completed, the deaerator water level setting loop exits. If there is a deviation between the deaerator water level and the standard deaerator water level setting, the loop switches to the deaerator water level recovery control loop to set the deaerator water level setting value to the standard value, thereby restoring the deaerator water level and allowing the unit to restore energy storage for the next use. At this time, the deaerator water level setting is switched to operator control.

[0026] Secondly, embodiments of this application provide a deaerator water level control system adapted to rapid load changes in thermal power units, comprising:

[0027] The deaerator water level setpoint calculation module is used to calculate the deaerator water level setpoint by means of the deviation between the load target value and the actual load of the unit under the condition that the deaerator water level control loop is engaged.

[0028] The water level tracking and regulation module is used to send the deaerator water level setpoint to the PID2 controller for water level tracking and regulation.

[0029] The dynamic feedforward generation unit is used to generate dynamic feedforward, which is superimposed on the output of the PID2 controller. When the deaerator water level regulating valve is in automatic mode, the PID2 controller calculates the change in valve opening based on the change in the deaerator water level setpoint to control the condensate flow rate and adjust the steam extraction flow rate of each low-pressure heater so that the unit can briefly obtain or release some energy, thereby enabling the unit to respond quickly to load changes.

[0030] A computer-readable storage medium storing program code, which, when executed by a processor, implements the steps of the deaerator water level control method adapted to rapid load changes in thermal power units as described above.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] In the initial stages of load changes, compared to the original unit's coordinated control methods, this approach effectively enhances the unit's load response capability, increases the initial load change rate, and mitigates the lag issues caused by the large inertia and delay on the boiler side. During the later stages of load changes, it effectively reduces overshoot and improves load regulation stability. Furthermore, compared to existing condensate throttling technology, it simplifies the control loop and effectively controls deaerator water level changes within the safe operating range of the unit, ensuring the unit's safety during load variations. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the condensate throttling control logic provided in this application.

[0035] Figure 2 This is a schematic diagram of the system structure of this application.

[0036] Figure 3 The deaerator water level and its set value, as well as the hot well water level change curve, are shown in the figure.

[0037] Figure 4 The curves showing the changes in deaerator water level regulating valve opening, condensate flow rate, and turbine extraction steam rate during unit load changes after the deaerator water level control loop is activated.

[0038] Figure 5 Comparison curves of unit power changes during the initial stage of load variation with and without deaerator water level control loop in operation.

[0039] Figure 6 Comparison curves of unit power change during the entire load change process with and without deaerator water level control loop in operation. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0041] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0042] This application provides a deaerator water level control method adapted to rapid load changes in thermal power units. A 660MW ultra-supercritical unit is selected as the research object, and a simulation model that accurately characterizes the unit's operating state is established. The specific implementation method is as follows:

[0043] Under normal unit operation, the deaerator water level regulating valve is in automatic mode, and the deaerator water level control loop is engaged. For example... Figure 1 As shown, under condensate throttling control, the deaerator water level setpoint is determined by the deviation between the load target command and the actual unit load. The deaerator water level setpoint is calculated by the main loop PID1 controller. This setpoint is input to the secondary loop PID2 controller for water level tracking and adjustment. Simultaneously, upon receiving the load target command, the main steam pressure setpoint deviates from its multi-stage delayed speed-limited setpoint. This deviation is multiplied by the main steam pressure change rate after a first-stage delay, and combined with the load deviation to obtain dynamic feedforward. This feedforward is then superimposed on the PID2 controller output to control the condensate flow rate, resulting in more accurate control and enhanced condensate throttling capability.

[0044] During condensate throttling, changes in condensate flow rate affect the deaerator water level, which in turn affects the safe operation of the unit. The deaerator water level control method described above changes the deaerator water level setpoint and adjusts the controller output high and low limits according to the unit's high and low limits for the deaerator water level, leaving an adjustment margin, thereby ensuring that the deaerator water level changes within a safe range.

[0045] A dynamic feedforward based on parameters such as load deviation and main steam pressure command is designed in the deaerator water level control loop. When the unit receives a load change command, the main steam pressure setpoint is subtracted from the setpoint after multi-stage delay and speed limiting. After one first-stage delay, this subtracted value from the set main steam pressure change rate to obtain the main steam pressure feedforward factor. This factor is then multiplied by the load feedforward factor obtained from the load deviation to form a dynamic feedforward, which is applied to the secondary loop PID2 controller and superimposed with the PID2 output to control the condensate flow rate.

[0046] With the deaerator water level control loop in operation, the deaerator water level setpoint is calculated by PID1, and the opening of the deaerator water level regulating valve is obtained by superimposing the output of PID1 and dynamic feedforward. The transfer function calculation formula is as follows:

[0047]

[0048]

[0049] In the formula Lv sp Lv(s) is the deaerator water level setpoint, and Lv(s) is the deaerator water level.

[0050] ΔP(s) represents the deviation between the target load value and the actual load of the unit;

[0051] K p1 K p2 These are the proportional gains of PID1 and PID2, respectively;

[0052] T i1 T i2 These are the integral times for PID1 and PID2, respectively;

[0053] OP(s) is the deaerator water level regulating valve opening command;

[0054] FF(s) is a dynamic feedforward.

[0055] In the deaerator water level control loop designed in this invention, the water level setting PID1 controller and the regulating valve PID2 controller are tuned according to a cascade system. The regulating valve PID2 controller aims to quickly reach the water level setpoint without overshooting the deaerator water level; lambda tuning is recommended. The water level setting PID1 controller is tuned to ensure its operating speed does not exceed that of the inner loop. The dynamic feedforward amplitude is limited to ±15°.

[0056] The necessary condition for the deaerator water level control loop to be put into operation is that the deaerator water level regulating valve is in automatic mode. Under this condition, the unit's condensate system can control parameters such as condensate flow rate by changing the deaerator water level through the set value of the deaerator water level.

[0057] The exit conditions for the deaerator water level setting loop are designed as follows:

[0058] (1) When the main steam pressure deviation of the unit is less than 0.5 MPa and the load deviation of the unit is less than 1 MW, and the deviation is maintained for a certain period of time, the deaerator water level setting circuit is disconnected.

[0059] (2) When the deaerator water level regulating valve is switched to manual mode, the deaerator water level setting circuit is exited.

[0060] (3) When the condenser water level exceeds the set range, exit the deaerator water level setting circuit.

[0061] After the load regulation process is completed, the deaerator water level setting loop exits. If there is a deviation between the deaerator water level and the standard deaerator water level setting, the loop switches to the deaerator water level recovery control loop. Within a certain period of time, the deaerator water level setting value is set to the standard value, so that the deaerator water level is restored and the unit resumes energy storage for the next use. At this time, the deaerator water level setting is switched to operator control.

[0062] The purpose of the deaerator water level control loop is to adjust the steam extraction flow of the low-pressure heater. The adjustment process includes: When the deaerator water level control loop is engaged, if the load change command is to increase the load, a deviation will occur between the target load command and the actual load of the unit. To eliminate this deviation, the main loop PID1 calculates the deaerator water level setpoint based on the magnitude of the deviation and inputs it to the auxiliary loop PID2 controller. Dynamic feedforward calculated based on the load target and main steam pressure setpoint is then added to calculate the corresponding valve opening command, thereby reducing the condensate flow and decreasing the steam extraction from the low-pressure heater. This increases the amount of steam used for power in the turbine, temporarily increasing the unit load. When overshoot occurs after the actual load reaches the target load command, the deviation direction changes, and the change in the water level setpoint calculated by the PID1 controller also responds in the opposite direction. The deaerator water level rises, and the condensate flow increases, forming a counter-regulation effect, reducing the overshoot and making the adjustment process more stable. The load reduction process is the opposite.

[0063] like Figure 2 This application provides a deaerator water level control system adapted to rapid load changes in thermal power units, including a deaerator water level setpoint calculation module 1, which calculates the deaerator water level setpoint by the deviation between the load target value and the actual load of the unit through a PID1 controller when the deaerator water level control loop is engaged.

[0064] The water level tracking and regulation module 2 is used to send the deaerator water level setpoint to the PID2 controller for water level tracking and regulation.

[0065] The dynamic feedforward generation unit 3 is used to generate dynamic feedforward. The dynamic feedforward is superimposed on the output of the PID2 controller. When the deaerator water level regulating valve is in automatic mode, the PID2 controller calculates the change in the opening of the regulating valve according to the change in the deaerator water level set value, so as to control the condensate flow rate and adjust the steam extraction flow rate of each low-pressure heater so that the unit can briefly obtain or release some energy, thereby realizing the unit's rapid response to load changes.

[0066] This implementation method involves a load adjustment test at 360MW unit operating conditions, reducing the load to 50% of the unit's operating capacity. During the load adjustment process, the changes in the deaerator water level setpoint and parameters such as the deaerator and condenser water levels are detailed below. Figure 3 , Figure 4 .

[0067] In the initial stage of load reduction, to ensure the actual unit load changes in the direction of the load target command, the PID1 controller calculates the increment of the deaerator water level setpoint. The increase in the deaerator water level setpoint causes the opening of the deaerator water level regulating valve to increase. Simultaneously, dynamic feedforward further increases the valve opening, and the combined effect leads to a rapid increase in condensate flow rate in the initial stage of load change. The saturated steam pressure on the shell side of the low-pressure heater decreases, reducing the difference with the extraction steam pressure, thereby increasing the extraction steam volume. This reduces the amount of steam required for turbine work, enabling the unit to quickly release part of the load and achieve rapid response in load regulation for thermal power units.

[0068] In the later stages of load regulation, once the unit load stabilizes near the load command and the deviation between the main steam pressure and the main steam pressure command stabilizes and approaches zero, the deaerator water level control loop exit condition is triggered. The deaerator water level regulation switches to the deaerator water level recovery control loop, and the setpoint is adjusted back to the standard water level value within a certain period of time. At this time, the deaerator water level decreases with the setpoint, the opening of the regulating valve decreases, the condensate flow rate decreases, and the extraction steam rate also decreases, achieving a reverse regulation effect. This reduces the overshoot during the load regulation process, and the unit load can stabilize to the load target more quickly.

[0069] The optimization effects of this implementation method are as follows:

[0070] Compared with the original coordinated control system, this implementation method improves the load change rate by 4.5 MW / min in the initial stage of load change. Figure 5 The following curves are given regarding the initial power variation of thermal power units under varying loads when the deaerator water level control loop is engaged or disengaged. Figure 6The unit power change curve for the complete load change process is presented. Due to the deaerator water level recovery, condensate throttling plays a counter-regulating role, reducing the overshoot of load regulation and enabling the load change to quickly stabilize to the target load command. The regulation dead zone is 0.5% of the unit's rated capacity. Experimental data shows that during the load change process with the deaerator water level control loop engaged, the overshoot is reduced by 1.18 MW and does not exceed the regulation dead zone, while under the original coordinated control, the overshoot is 3.325 MW, exceeding the regulation dead zone. It is evident that the control method of this invention can effectively enhance the unit's regulation capability during load changes.

[0071] In summary, the test results show that the deaerator water level control method of the present invention, which is adapted to rapid load change of thermal power units, improves the response rate of thermal power units in the initial stage of load change, realizes optimized control of condensate throttling of thermal power units, and enhances the adjustment capability of units in the later stage of load change.

[0072] This application discloses a computer-readable storage medium storing program code, which, when executed by a processor, implements the steps of the deaerator water level control method adapted to rapid load changes in thermal power units as described above.

[0073] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0074] 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.

[0075] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0076] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0077] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0078] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0079] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0080] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0081] The above description is merely an embodiment of this application and is not intended to limit the scope of protection 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 protection of this application.

Claims

1. A method for controlling the water level of a deaerator adapted to variable load of a thermal power unit, characterized in that, The method comprises the following specific steps: Under the condition of inputting the deaerator water level control loop, the deviation between the load target value and the actual load of the unit is used to calculate the deaerator water level set value by the main loop PID1 controller; The deaerator water level set value is sent to the secondary loop PID2 controller for water level tracking adjustment; When the deaerator water level regulating valve is in an automatic state, the PID2 controller calculates the change amount of the regulating valve opening degree according to the change of the deaerator water level set value, so as to control the condensate flow, adjust the steam extraction flow of each low-pressure heater, and make the unit obtain or release part of energy, thereby realizing the unit response to load change; A dynamic feedforward based on load deviation and main steam pressure instruction parameter is designed in the deaerator water level control loop. When the unit receives a load change instruction, the main steam pressure set value is subtracted from the main steam pressure set value after multi-stage delay and speed limiting, and then the main steam pressure feedforward factor is obtained by multiplying the set main steam pressure change rate after one-stage delay. The main steam pressure feedforward factor is multiplied by the load feedforward factor obtained from the deviation between the load target value and the actual load of the unit to form a dynamic feedforward. The dynamic feedforward acts on the secondary loop PID2 controller and is superimposed with the PID2 controller output to control the condensate flow. Under the condition of inputting the deaerator water level control loop, the deaerator water level set value is calculated by the PID1 controller, and the deaerator water level regulating valve opening degree is obtained by superimposing the output of the PID1 controller and the dynamic feedforward. The transfer function calculation formula is as follows: (1) (2) In the formula set value for deaerator water level, deaerator water level; is the deviation of the load target value from the actual load of the unit; , Kp1 and Kp2 are the proportional gains of the PID1 controller and the PID2 controller, respectively; , are the integral times of the PID1 controller and the PID2 controller, respectively; Deaerator water level control valve opening command; is a dynamic feedforward.

2. The method for controlling the water level of a deaerator adapted to variable loads of a thermal power unit according to claim 1, characterized in that, In the deaerator water level control loop, the PID1 controller and the PID2 controller are adjusted according to a cascade system. The PID2 controller principle is that the deaerator water level reaches the water level set value without overshoot. Lambda adjustment is used. The PID1 controller adjustment principle is that the action speed does not exceed the inner loop. The action range of the dynamic feedforward is limited to plus or minus 15.

3. The method for controlling the water level of a deaerator adapted to variable loads of a thermal power unit according to claim 1, characterized in that, The deaerator water level control method suitable for variable load of a thermal power unit further comprises designing an exit condition of the deaerator water level setting loop, specifically, (1) When the unit main steam pressure deviation is less than 0.5 Mpa and the unit load deviation is less than 1 MW, and the conditions are maintained for a certain time, the deaerator water level setting loop is exited, (2) When the deaerator water level regulating valve is switched to a manual state, the deaerator water level setting loop is exited; (3) When the condenser water level exceeds the set range, the deaerator water level setting loop is exited; When the load adjustment process is completed, the deaerator water level setting loop is exited, and there is a deviation between the deaerator water level and the standard deaerator water level setting, the deaerator water level is switched to the deaerator water level recovery control loop, the deaerator water level set value is set to the standard value, the deaerator water level is recovered, the unit is restored to store energy for next use, and at this time, the deaerator water level setting is switched to the operator control.

4. A deaerator water level control system adapted to variable load of a thermal power unit for implementing the method of any one of claims 1-3, characterized in that, The method comprises the following specific steps: The deaerator water level set value calculation module is used to calculate the deaerator water level set value by the PID1 controller under the condition of inputting the deaerator water level control loop, and the deviation between the load target value and the actual load of the unit; The water level tracking adjustment module is used to send the deaerator water level set value to the PID2 controller for water level tracking adjustment; The dynamic feedforward generating unit is used to generate a dynamic feedforward, which is superimposed on the output of a PID2 controller, and the deaerator water level regulating valve is in an automatic state, and the PID2 controller calculates the change of the regulating valve opening according to the change of the deaerator water level set value, so as to control the condensate water flow and adjust the steam extraction flow of each low-pressure heater, so that the unit obtains or releases part of energy, and the unit responds to the load change.

5. A computer readable storage medium, characterized in that, The computer readable storage medium stores program codes, and the program codes are executed by the processor to realize the steps of the deaerator water level control method suitable for the variable load of the thermal power unit according to any one of claims 1 to 3.

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