A speed control system, control method and controller for a steam-driven feedwater pump

Abstract

This application discloses a speed-up control system, control method, and controller for a steam-driven feedwater pump. The speed-up control system includes a PID controller, a start-up control valve, a load control valve, and a controller. The PID controller has an 8-second operating cycle and a dead zone of 15 revolutions. The controller controls the load control valve to be fully open and reduces the opening of the start-up control valve based on the output value of the PID controller, causing the pump speed of the steam-driven feedwater pump to increase from the turning gear speed to a first target speed. When the pump speed of the steam-driven feedwater pump reaches the first target speed, the start-up control valve is controlled to be closed. The opening of the load control valve is reduced, causing the pump speed of the steam-driven feedwater pump to increase from the first target speed to a second target speed. In this embodiment, by setting the operating cycle of the PID controller to 8 seconds, the number of output changes of the PID controller is reduced, thereby increasing the service life of the start-up control valve.

Description

Technical Field

[0001] This application relates to the field of automation technology, and in particular to a speed control system, control method and controller for a steam-driven feedwater pump. Background Technology

[0002] The steam-driven feedwater pump system is an important component of the power plant's secondary loop system. Its function is to extract water from the deaerator and send it to the steam generator via a high-pressure heater. A single steam-driven feedwater pump operates at approximately 50% of the water load. The difference between a steam-driven and an electric feedwater pump is that the electric pump uses electricity to drive its rotation, while the steam-driven pump uses main steam to drive its rotation. Due to the high temperature and pressure characteristics of the main steam, the control of the steam-driven feedwater pump must be integrated with the characteristics of the steam system control.

[0003] In related technologies, the logic algorithm of the steam-driven feedwater pump speed-up control system is complex, and the controlled objects are high-temperature, high-pressure steam and high-pressure starting oil. However, this control method leads to frequent operation of the starting control valve, thereby reducing the life of the starting control valve. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a speed control system, control method, and controller for a steam-driven feedwater pump, thereby improving the lifespan of the start-up control valve.

[0005] The embodiments of this application disclose the following technical solutions:

[0006] In a first aspect, embodiments of this application provide a speed control system for a steam-driven feedwater pump. The speed control system includes: a proportional-integral-derivative controller, a start control valve, a load control valve, and a controller; wherein the operation cycle of the proportional-integral-derivative controller is set to 8s, and the adjustment dead zone is set to 15 revolutions.

[0007] The controller is used to keep the load control valve fully open and reduce the opening of the start control valve according to the output value of the proportional-integral-derivative controller, so that the pumping speed of the steam-driven feedwater pump increases from the turning speed to the first target speed; when the pumping speed of the steam-driven feedwater pump is the first target speed, the controller controls the start control valve to be closed; and reduces the opening of the load control valve so that the pumping speed of the steam-driven feedwater pump increases from the first target speed to the second target speed.

[0008] In one implementation, the controller is specifically used to acquire the output value N of the proportional-integral-derivative controller; when N is an integer greater than or equal to 1, N-1 is decremented in each operation cycle; if N-1 is an integer greater than or equal to 1, the control reduces the opening of the start control valve until N-1 is 0.

[0009] In one implementation, the controller is specifically used to reduce the opening of the start control valve and increase the inertial oil pressure according to the output value of the proportional-integral-derivative controller; in response to the increase in inertial oil pressure, the controller controls the hydraulic drive device to change the opening of the first steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate through the steam, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the first target speed.

[0010] In one implementation, the controller is specifically used to reduce the opening of the load control valve and increase the inertial oil pressure when the pumping speed of the steam-driven feedwater pump is at a first target speed; in response to the increase in inertial oil pressure, the controller controls the hydraulic drive device to change the opening of the second steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate through steam, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the second target speed.

[0011] In one implementation, the controller is also used to acquire pressure parameters, temperature parameters, and vibration parameters of the steam-driven feedwater pump; and to monitor the acceleration process of the steam-driven feedwater pump based on the pressure parameters, temperature parameters, and vibration parameters.

[0012] Secondly, embodiments of this application provide a method for controlling the speed increase of a steam-driven feedwater pump, the method comprising:

[0013] The load control valve is kept fully open.

[0014] The opening of the start control valve is reduced according to the output value of the proportional-integral-derivative controller, so that the pumping speed of the steam-driven feedwater pump increases from the turning speed to the first target speed; wherein, the operation cycle of the proportional-integral-derivative controller is set to 8s, and the adjustment dead zone is set to 15 revolutions.

[0015] When the pumping speed of the steam-driven feedwater pump is the first target speed, the start control valve is kept closed.

[0016] Reduce the opening of the load control valve to increase the pumping speed of the steam-driven feedwater pump from the first target speed to the second target speed.

[0017] In one implementation, reducing the opening of the start-up control valve based on the output value of the proportional-integral-derivative controller includes:

[0018] Obtain the output value N of the proportional-integral-derivative controller;

[0019] When N is an integer greater than or equal to 1, N-1 is processed in each operation cycle. If N-1 is an integer greater than or equal to 1, the opening of the start control valve is reduced until N-1 is 0.

[0020] In one implementation, the opening of the start-up control valve is reduced based on the output value of the proportional-integral-derivative controller, causing the pumping speed of the steam-driven feedwater pump to increase from the turning gear speed to the first target speed, including:

[0021] The opening of the start control valve is reduced based on the output value of the proportional-integral-derivative controller, thereby increasing the inertial oil pressure;

[0022] In response to the increase in inertial oil pressure, the hydraulic drive device is controlled to change the opening of the first steam regulating valve. The steam drives the blades of the steam-driven feedwater pump to rotate, thereby increasing the pumping speed of the steam-driven feedwater pump until the pumping speed of the steam-driven feedwater pump reaches the first target speed.

[0023] In one implementation, reducing the opening of the load control valve to increase the pumping speed of the steam-driven feedwater pump from a first target speed to a second target speed includes:

[0024] When the pumping speed of the steam-driven feedwater pump is the first target speed, reduce the opening of the load control valve and increase the inert oil pressure;

[0025] In response to the increase in inertial oil pressure, the hydraulic drive device is controlled to change the opening of the second steam regulating valve. The steam drives the blades of the steam-driven feedwater pump to rotate, thereby increasing the pumping speed of the steam-driven feedwater pump until the pumping speed of the steam-driven feedwater pump reaches the second target speed.

[0026] Thirdly, embodiments of this application provide a controller for executing the speed control method for a steam-driven feedwater pump described in any embodiment of the first aspect.

[0027] To improve the service life of the start-up control valve, this application provides a speed-up control system for a steam-driven feedwater pump, including a proportional-integral-derivative (PI-DI) controller, a start-up control valve, a load control valve, and a controller. The PI-DI controller has an operation cycle of 8 seconds and a dead zone of 15 revolutions. The controller controls the load control valve to be fully open and reduces the opening of the start-up control valve based on the output value of the PI-DI controller, causing the pumping speed of the steam-driven feedwater pump to increase from the turning speed to a first target speed. When the pumping speed of the steam-driven feedwater pump reaches the first target speed, the start-up control valve is controlled to be closed. The load control valve opening is reduced, causing the pumping speed of the steam-driven feedwater pump to increase from the first target speed to a second target speed. In this application embodiment, the output value of the PI-DI controller is used to control the start-up control valve. By setting the operation cycle of the PI-DI controller to 8 seconds, the number of output changes of the PI-DI controller is reduced, thereby reducing the number of operations of the start-up control valve and improving its service life.

[0028] In addition, this embodiment sets the dead zone of the proportional-integral-derivative controller to 15 revolutions. An action command is only output when the deviation between the current speed and the set value exceeds 15 revolutions. Since the set value during the acceleration process is a continuously increasing variable (such as a linear ramp), the deviation will not frequently exceed the dead zone, thereby further reducing unnecessary valve actions and further improving the service life of the start-up control valve. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0030] Figure 1 A schematic diagram of a speed control system for a steam-driven feedwater pump provided in an embodiment of this application;

[0031] Figure 2 A schematic diagram of the acceleration curve of a steam-driven feedwater pump provided in an embodiment of this application;

[0032] Figure 3 This application provides a schematic diagram of the control of a start-up control valve.

[0033] Figure 4 A flowchart illustrating a speed control method for a steam-driven feedwater pump provided in an embodiment of this application. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0035] The terms "first" and "second," etc., used in the specification and claims of this application are used to distinguish different objects, not to describe a specific order of objects. For example, "first grid" and "second grid," etc., are used to distinguish different grids, not to describe a specific order of grids.

[0036] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0037] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0038] See Figure 1 The figure is a schematic diagram of a speed control system for a steam-driven feedwater pump provided in an embodiment of this application.

[0039] like Figure 1 As shown, the pneumatic speed control system includes: a proportional-integral-derivative PID controller 100, a controller 200, a start control valve 300, and a load control valve 400.

[0040] The PID controller 100 has an operation cycle of 8 seconds and a dead zone of 15 revolutions.

[0041] The controller 200 is used to control the load control valve 400 to be fully open, and to reduce the opening of the start control valve 300 according to the output value of the proportional-integral-derivative controller 100, so that the pumping speed of the steam-driven feedwater pump increases from the turning speed to the first target speed; when the pumping speed of the steam-driven feedwater pump is the first target speed, the controller controls the start control valve 300 to be closed; and reduces the opening of the load control valve 400, so that the pumping speed of the steam-driven feedwater pump increases from the first target speed to the second target speed.

[0042] It should be understood that the embodiments of this application do not specifically limit the method of increasing the pumping speed of the steam-driven feedwater pump, and the method of increasing the pumping speed of the steam-driven feedwater pump can be a step-by-step increase.

[0043] For example, such as Figure 2As shown, the turning speed is 128 r / min, and the first target speed is 4300 r / min. Within the 0s-120s range, the pumping speed of the steam-driven feedwater pump increases from 128 r / min to 700 r / min; within the 120s-900s range, the pumping speed remains at 700 r / min; within the 900s-2070s range, the pumping speed increases from 700 r / min to 3800 r / min; and within the 2310s-2396s range, the pumping speed increases from 3800 r / min to 4300 r / min.

[0044] It should be noted that in this embodiment, during the interval from 2396s to 2932s, the start control valve remains closed, and the pumping speed of the steam-driven feedwater pump increases, that is, the pumping speed of the steam-driven feedwater pump increases from 4300r / min to 5600r / min, which is due to the control of the load control valve.

[0045] Based on the above example, the continuous operation time of the start control valve is 2932s. If the controller cycle is 50ms, the theoretical output of the PID controller changes 58,000 times, and the theoretical start control valve operates 58,000 times. Too many valve operations in a short period of time will affect the valve's service life.

[0046] To quickly eliminate the deviation between the setpoint and the given value, the faster the PID response, the faster the system can stabilize. However, the setpoint of the speed control system is a continuously increasing variable, and the requirement for deviation is not high. Therefore, in order to protect the stability of the speed control system, the operation cycle of the PID in the control system is set to 8 seconds, and the adjustment dead zone is set to 15 revolutions. After adjustment, the number of times the control valve is started is about 100 times, which greatly reduces the number of valve actions.

[0047] Therefore, in this embodiment, the output value of a proportional-integral-derivative (PID) controller is used to control the start-up control valve. By setting the PID controller's operation cycle to 8 seconds, the number of output changes is reduced, thereby reducing the number of start-up control valve actions and increasing the valve's lifespan. Furthermore, this embodiment sets the PID controller's dead zone to 15 revolutions; an action command is only output when the deviation between the current speed and the set value exceeds 15 revolutions. Since the set value during the acceleration process is a continuously increasing variable (such as a linear ramp), the deviation will not frequently exceed the dead zone, further reducing unnecessary valve actions and further improving the start-up control valve's lifespan.

[0048] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the speed control system of the steam-driven feedwater pump will be described below with reference to the accompanying drawings.

[0049] In one possible implementation, the controller is specifically used to acquire the output value N of the proportional-integral-derivative controller; when N is an integer greater than or equal to 1, N-1 is processed in each operation cycle; if N-1 is an integer greater than or equal to 1, the control reduces the opening of the start control valve until N-1 is 0.

[0050] The PID controller outputs an analog value, and the start-up control valve is a pulse regulating valve. The control of the start-up control valve is as follows: Figure 3 As shown, the controller rounds the output value of the PID controller to an integer N and sends N to the counting unit. If N is positive, it decreases by 1 in each scan cycle until N=0, at which point the valve closes and the speed increases. If N is negative, it increases by 1 in each controller scan cycle until N=0, at which point the valve opens and the speed decreases. The DCS scan cycle is 50ms, and the valve output time is 50*Nms.

[0051] Specifically, the controller reduces the opening of the start control valve and increases the inertial oil pressure based on the output value of the proportional-integral-derivative controller; in response to the increase in inertial oil pressure, the controller controls the hydraulic drive device to change the opening of the first steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate through the steam, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the first target speed.

[0052] In one possible implementation, the controller is used to reduce the opening of the load control valve and increase the inertial oil pressure when the pumping speed of the steam-driven feedwater pump is at a first target speed; in response to the increase in inertial oil pressure, the controller controls the hydraulic drive device to change the opening of the second steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate through steam, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the second target speed.

[0053] It should be noted that, in the embodiments of this application, the specific types of the first steam regulating valve and the second steam regulating valve are not specifically limited.

[0054] It should be noted that the relationship between the first steam regulating valve and the second steam regulating valve is not specifically limited in the embodiments of this application. For example, the first steam regulating valve and the second steam regulating valve can be the same steam regulating valve, or they can be two independent steam regulating valves.

[0055] In this embodiment, the output value of a proportional-integral-derivative (PID) controller is used to control the start-up control valve. By setting the PID controller's operation period to 8 seconds, the number of output changes is reduced, thereby reducing the number of valve actions and extending the valve's lifespan. Furthermore, this embodiment sets the PID controller's dead zone to 15 revolutions; an action command is only output when the deviation between the current speed and the set value exceeds 15 revolutions. Since the set value during the acceleration process is a continuously increasing variable (such as a linear ramp), the deviation will not frequently exceed the dead zone, further reducing unnecessary valve actions and extending the valve's lifespan.

[0056] In addition, in this embodiment, the controller is also used to acquire the pressure parameters, temperature parameters, and vibration parameters of the steam-driven feedwater pump; and to monitor the speed-up process of the steam-driven feedwater pump based on the pressure parameters, temperature parameters, and vibration parameters.

[0057] For example, pressure parameters may include inlet steam pressure (steam inlet pressure at the turbine drive end), inlet steam temperature (steam inlet temperature at the turbine drive end), feedwater outlet pressure (feedwater pressure at the pump outlet), and feedwater inlet pressure (feedwater pressure at the pump inlet), etc.

[0058] Temperature parameters may include bearing temperature (temperature of front and rear bearings), pump casing temperature (temperature of the upper and lower parts of the pump body), motor / turbine winding temperature, feedwater outlet temperature, and lubricating oil temperature, etc.

[0059] Vibration parameters can include bearing vibration (including vertical, horizontal and axial vibration velocities or displacements), shaft vibration (relative and absolute shaft vibrations measured by non-contact probes), and vibration spectra.

[0060] In the event of abnormal pressure, temperature, or vibration parameters, the controller in this embodiment can issue an alarm; when the above parameters are normal, it controls the steam-driven feedwater pump to continue to increase its speed.

[0061] It should be understood that the embodiments of this application do not specifically limit the methods for judging abnormal pressure parameters, abnormal temperature parameters, or abnormal vibration parameters.

[0062] Based on the aforementioned speed control system for steam-driven feedwater pumps, this application provides a speed control method for steam-driven feedwater pumps, the flowchart of which is shown below. Figure 4 As shown:

[0063] S100: Controls the load control valve to be fully open;

[0064] S200: Based on the output value of the proportional-integral-derivative controller, the opening of the start control valve is reduced, so that the pumping speed of the steam-driven feedwater pump increases from the turning speed to the first target speed; wherein, the operation cycle of the proportional-integral-derivative controller is set to 8s, and the adjustment dead zone is set to 15 revolutions;

[0065] S300: When the pumping speed of the steam-driven feedwater pump is the first target speed, the start control valve is kept closed.

[0066] S400: Reduce the opening of the load control valve to increase the pumping speed of the steam-driven feedwater pump from the first target speed to the second target speed.

[0067] In this embodiment, the output value of a proportional-integral-derivative (PID) controller is used to control the start-up control valve. By setting the PID controller's operation period to 8 seconds, the number of output changes is reduced, thereby reducing the number of valve actions and extending the valve's lifespan. Furthermore, this embodiment sets the PID controller's dead zone to 15 revolutions; an action command is only output when the deviation between the current speed and the set value exceeds 15 revolutions. Since the set value during the acceleration process is a continuously increasing variable (such as a linear ramp), the deviation will not frequently exceed the dead zone, further reducing unnecessary valve actions and extending the valve's lifespan.

[0068] In one implementation, reducing the opening of the start-up control valve based on the output value of the proportional-integral-derivative controller includes:

[0069] Obtain the output value N of the proportional-integral-derivative controller;

[0070] When N is an integer greater than or equal to 1, N-1 is processed in each operation cycle. If N-1 is an integer greater than or equal to 1, the opening of the start control valve is reduced until N-1 is 0.

[0071] In one implementation, the opening of the start-up control valve is reduced based on the output value of the proportional-integral-derivative controller, causing the pumping speed of the steam-driven feedwater pump to increase from the turning gear speed to the first target speed, including:

[0072] The opening of the start control valve is reduced based on the output value of the proportional-integral-derivative controller, thereby increasing the inertial oil pressure;

[0073] In response to the increase in inertial oil pressure, the hydraulic drive device is controlled to change the opening of the first steam regulating valve. The steam drives the blades of the steam-driven feedwater pump to rotate, thereby increasing the pumping speed of the steam-driven feedwater pump until the pumping speed of the steam-driven feedwater pump reaches the first target speed.

[0074] In one implementation, reducing the opening of the load control valve to increase the pumping speed of the steam-driven feedwater pump from a first target speed to a second target speed includes:

[0075] When the pumping speed of the steam-driven feedwater pump is the first target speed, reduce the opening of the load control valve and increase the inert oil pressure;

[0076] In response to the increase in inertial oil pressure, the hydraulic drive device is controlled to change the opening of the second steam regulating valve. The steam drives the blades of the steam-driven feedwater pump to rotate, thereby increasing the pumping speed of the steam-driven feedwater pump until the pumping speed of the steam-driven feedwater pump reaches the second target speed.

[0077] In addition, this application provides a controller for executing the speed control method for the steam-driven feedwater pump described in any of the foregoing embodiments.

[0078] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the method embodiments are basically similar to the system embodiments, so the description is relatively simple, and the relevant parts can be referred to the description of the system embodiments.

[0079] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A speed control system for a steam-driven feedwater pump, characterized in that, The speed control system includes: a proportional-integral-derivative controller, a start control valve, a load control valve, and a controller; wherein the operation cycle of the proportional-integral-derivative controller is set to 8s, and the adjustment dead zone is set to 15 revolutions; The controller is used to control the load control valve to be fully open, and to reduce the opening of the start control valve according to the output value of the proportional-integral-derivative controller, so that the pumping speed of the steam-driven feedwater pump increases from the turning gear speed to a first target speed; when the pumping speed of the steam-driven feedwater pump is the first target speed, the controller controls the start control valve to be closed; and reduces the opening of the load control valve, so that the pumping speed of the steam-driven feedwater pump increases from the first target speed to a second target speed. The controller is specifically used to obtain the output value N of the proportional-integral-derivative controller; when N is an integer greater than or equal to 1, N-1 is applied in each operation cycle; if N-1 is an integer greater than or equal to 1, the opening of the start control valve is reduced until N-1 is 0. The controller is specifically used to reduce the opening of the start control valve and increase the inertial oil pressure according to the output value of the proportional-integral-derivative controller; in response to the increase of the inertial oil pressure, it controls the hydraulic drive device to change the opening of the first steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate through the steam, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the first target speed. The controller is specifically configured to, when the pumping speed of the steam-driven feedwater pump is the first target speed, reduce the opening of the load control valve and increase the inertial oil pressure; in response to the increase of the inertial oil pressure, control the hydraulic drive device to change the opening of the second steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate through steam, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the second target speed.

2. The speed control system according to claim 1, characterized in that, The controller is also used to acquire the pressure parameters, temperature parameters, and vibration parameters of the steam-driven feedwater pump; and to monitor the speed-up process of the steam-driven feedwater pump based on the pressure parameters, temperature parameters, and vibration parameters.

3. A method for controlling the speed increase of a steam-driven feedwater pump, characterized in that, The method, applied to the speed control system of the steam-driven feedwater pump according to claim 1 or 2, comprises: The load control valve is in the fully open position. The opening of the start control valve is reduced according to the output value of the proportional-integral-derivative controller, so that the pumping speed of the steam-driven feedwater pump increases from the turning speed to the first target speed; wherein, the operation cycle of the proportional-integral-derivative controller is set to 8s, and the adjustment dead zone is set to 15 revolutions; When the pumping speed of the steam-driven feedwater pump is the first target speed, the start control valve is controlled to be in the closed state; Reduce the opening of the load control valve to increase the pumping speed of the steam-driven feedwater pump from the first target speed to the second target speed.

4. The acceleration control method according to claim 3, characterized in that, The step of reducing the opening of the start control valve based on the output value of the proportional-integral-derivative controller includes: Obtain the output value N of the proportional-integral-derivative controller; When N is an integer greater than or equal to 1, N-1 is applied within each operation cycle. If N-1 is an integer greater than or equal to 1, the opening of the start control valve is reduced until N-1 is 0.

5. The acceleration control method according to claim 3 or 4, characterized in that, The step of reducing the opening of the start control valve based on the output value of the proportional-integral-derivative controller, so that the pumping speed of the steam-driven feedwater pump increases from the turning gear speed to the first target speed, includes: The opening of the start-up control valve is reduced according to the output value of the proportional-integral-derivative controller, thereby increasing the inertial oil pressure; In response to the increase in inertial oil pressure, the hydraulic drive device is controlled to change the opening of the first steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the first target speed.

6. The acceleration control method according to claim 3 or 4, characterized in that, Reducing the opening of the load control valve to increase the pumping speed of the steam-driven feedwater pump from the first target speed to the second target speed includes: When the pumping speed of the steam-driven feedwater pump is the first target speed, reduce the opening of the load control valve and increase the inert oil pressure; In response to the increase in inertial oil pressure, the hydraulic drive device is controlled to change the opening of the second steam regulating valve, thereby driving the blades of the steam-driven feedwater pump to rotate, so that the pumping speed of the steam-driven feedwater pump increases until the pumping speed of the steam-driven feedwater pump reaches the second target speed.

7. A controller, characterized in that, The controller is used to execute the speed control method for the steam-driven feedwater pump according to any one of claims 3-6.

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