Coaxial water pump stop control method and device

Abstract

The present invention discloses a coaxial feedwater pump stop control method and device, which relate to the technical field of feedwater pump stop control. The method comprises: obtaining parameters of a steam turbine coaxial drive feedwater pump system in real time; when the coaxial feedwater pump fails or needs to be shut down for maintenance, controlling the speed of the coaxial feedwater pump to decrease; when the speed of the coaxial feedwater pump decreases to less than a first preset speed, calling and executing an electric feedwater pump parallel pump program; when the electric feedwater pump parallel pump program is completed, controlling the speed of the coaxial feedwater pump to decrease to zero by controlling a hydraulic coupling and a disc brake in sequence, thereby providing a more accurate and reasonable coaxial feedwater pump stop control logic, improving the degree of automation of equipment operation while ensuring the safe operation of a steam turbine coaxial drive feedwater pump system that applies the steam turbine coaxial drive feedwater pump technology, reducing manual workload, and avoiding errors that may be caused by manual judgment of equipment failures.

Description

Technical Field

[0001] The present invention relates to the technical field of stop control of a coaxial water supply pump, and in particular to a stop control method and device for a coaxial water supply pump. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the invention that are recited in the claims. No statement herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] The research on (steam turbine) coaxial-driven feedwater pump technology is complex, and the shutdown control method differs from conventional steam-driven or electric feedwater pump systems, requiring precise coordination of all components. Currently, the automation level for shutting down coaxial feedwater pumps in the event of an accident or maintenance is relatively low, with many steps heavily reliant on manual operation by operators. This increases the risk of disrupting the boiler water level during the shut-down of the coaxial feedwater pump, impacting the safe and stable operation of the equipment and the steam turbine coaxial-driven feedwater pump system. Summary of the Invention

[0004] An embodiment of the present invention provides a coaxial feed water pump stop control method, which is used to provide more accurate and reasonable coaxial feed water pump stop control logic, while ensuring the safe operation of the turbine coaxial drive feed water pump system that uses the turbine coaxial drive feed water pump technology, improving the degree of automation of equipment operation, reducing manual workload, and avoiding errors that may be caused by manual judgment of equipment failures.

[0005] The coaxial feedwater pump stop control method is applied to a control device connected to a coaxially driven feedwater pump system of a steam turbine; the coaxially driven feedwater pump system of the steam turbine comprises: a steam turbine, a feedwater pump system, a speed regulating system respectively connected to the steam turbine and the feedwater pump system, and a boiler connected to the feedwater pump system; the steam turbine is used to drive the feedwater pump system; the speed regulating system is used to regulate the speed of the feedwater pump system; the feedwater pump system is used to supply water to the boiler; the feedwater pump system comprises a coaxial feedwater pump and an electric feedwater pump; the electric feedwater pump is connected to the coaxial feedwater pump; the speed regulating system comprises: a hydraulic torque converter, a disc brake, a hydraulic brake, and a hydraulic coupling; the shaft power of the steam turbine is divided into two shafts after being transmitted through the input end of the speed regulating system, one shaft is connected to the hydraulic torque converter and the hydraulic brake in sequence; the other shaft is connected to the hydraulic coupling and the disc brake in sequence;

[0006] The coaxial feedwater pump stop control method includes:

[0007] Real-time acquisition of parameters of the steam turbine coaxially driven feedwater pump system; the parameters include load of the steam turbine coaxially driven feedwater pump system and measurement data of measuring points;

[0008] When the coaxial water feed pump fails or needs to be shut down for maintenance, the speed of the coaxial water feed pump is reduced by controlling the hydraulic torque converter, the hydraulic brake, and the hydraulic coupling in sequence according to the parameters;

[0009] When the speed of the coaxial feedwater pump decreases to less than the first preset speed, the electric feedwater pump parallel program is called and executed; the electric feedwater pump parallel program is used to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler;

[0010] When the electric water pump paralleling program is completed, the speed of the coaxial water pump is controlled to be reduced to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters.

[0011] An embodiment of the present invention also provides a coaxial feed water pump stop control device, which is used to provide more accurate and reasonable coaxial feed water pump stop control logic, while ensuring the safe operation of the turbine coaxial drive feed water pump system that uses turbine coaxial drive feed water pump technology, improving the degree of automation of equipment operation, reducing manual workload, and avoiding errors that may be caused by manual judgment of equipment failures.

[0012] The coaxial feedwater pump stop control device is applied to a control device connected to a coaxially driven feedwater pump system of a steam turbine; the coaxially driven feedwater pump system of the steam turbine comprises: a steam turbine, a feedwater pump system, a speed regulating system respectively connected to the steam turbine and the feedwater pump system, and a boiler connected to the feedwater pump system; the steam turbine is used to drive the feedwater pump system; the speed regulating system is used to regulate the speed of the feedwater pump system; the feedwater pump system is used to supply water to the boiler; the feedwater pump system comprises a coaxial feedwater pump and an electric feedwater pump; the electric feedwater pump is connected to the coaxial feedwater pump; the speed regulating system comprises: a hydraulic torque converter, a disc brake, a hydraulic brake, and a hydraulic coupling; the shaft power of the steam turbine is divided into two shafts after being transmitted through the input end of the speed regulating system, one shaft being connected to the hydraulic torque converter and the hydraulic brake in sequence; the other shaft being connected to the hydraulic coupling and the disc brake in sequence;

[0013] The coaxial feed water pump stop control device includes:

[0014] An acquisition module is used to acquire parameters of the steam turbine coaxially driven feedwater pump system in real time; the parameters include the load of the steam turbine coaxially driven feedwater pump system and measurement data of measurement points;

[0015] The first control module is configured to control the torque converter and the hydraulic brake in sequence to reduce the speed of the coaxial water feed pump according to the parameters when the coaxial water feed pump fails or needs to be shut down for maintenance;

[0016] A pump paralleling module is configured to call and execute an electric feedwater pump paralleling program when the rotational speed of the coaxial feedwater pump decreases to less than a first preset rotational speed; the electric feedwater pump paralleling program is configured to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler;

[0017] The second control module is used to control the rotation speed of the coaxial water pump to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters after the electric water pump parallel pump program is executed.

[0018] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned coaxially driven water pump stop control method when executing the computer program.

[0019] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned coaxial water supply pump stop control method is implemented.

[0020] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the above-mentioned coaxial water supply pump stop control method is implemented.

[0021] Compared with the prior art, the embodiments of the present invention obtain parameters of the steam turbine coaxially driven feedwater pump system in real time; the parameters include the load of the steam turbine coaxially driven feedwater pump system and the measurement data of the measuring points; when the coaxial feedwater pump fails or needs to be shut down for maintenance, the speed of the coaxial feedwater pump is controlled to be reduced by controlling the torque converter and the hydraulic brake in sequence according to the parameters; when the speed of the coaxial feedwater pump is reduced to less than a first preset speed, the electric feedwater pump parallel program is called and executed; the electric feedwater pump parallel program is used to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler; when the electric feedwater pump parallel program is completed, the speed of the coaxial feedwater pump is controlled to be reduced to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters, thereby providing a more accurate and reasonable coaxial feedwater pump stop control logic, ensuring the safe operation of the steam turbine coaxially driven feedwater pump system that applies the steam turbine coaxially driven feedwater pump technology, while improving the degree of automation of equipment operation, reducing manual workload, and avoiding errors that may be caused by manual judgment of equipment failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0023] Figure 1 This is a flow chart of a coaxial water supply pump stop control method according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic structural diagram of a steam turbine coaxially driven feedwater pump system according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic structural diagram of a water supply pump system according to an embodiment of the present invention;

[0026] Figure 4 This is a flow chart of a specific example of a coaxial water supply pump stop control method according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of a first working mode of a speed regulation system in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of a second working mode of a speed control system in an embodiment of the present invention;

[0029] Figure 7 This is a flow chart of a specific example of a parallel pumping procedure for electric water pumps according to an embodiment of the present invention;

[0030] Figure 8 This is a structural block diagram of a coaxial water supply pump stop control device according to an embodiment of the present invention;

[0031] Figure 9 Schematic diagram of a computer device in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] Embodiments of the present invention provide a method for controlling a coaxially driven feedwater pump of a steam turbine, a device for controlling a coaxially driven feedwater pump of a steam turbine, a computing device, a computer-readable storage medium, and a computer program product.

[0033] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0034] In view of the shortcomings of the prior art, the present invention proposes a coaxial feed water pump stop control method and device, which automatically controls the stop process of the coaxial feed water pump exiting the operation of the turbine coaxial drive feed water pump system, thereby achieving close and precise coordination of the coaxial feed water pump, the hydraulic coupling, hydraulic torque converter, hydraulic brake, diaphragm coupling and other components in the speed control system, and ensuring automatic and precise control of the speed control system during the entire process of switching between the first working mode and the second working mode. By applying the technical solution of the present invention, the cumbersome steps and possible misoperations of the operating personnel can be greatly reduced, the risk of boiler water shortage during the shutdown of the coaxial feed water pump due to failure is reduced, the automation level of the turbine coaxial drive feed water pump system is significantly improved, and the safe and stable operation of the coaxial feed water pump is guaranteed.

[0035] The stopping control concept of the coaxial feedwater pump of the present invention is as follows: (1) when the load of the coaxial drive feedwater pump system of the turbine is reduced or the coaxial feedwater pump needs to be withdrawn for maintenance due to a fault, the load of the coaxial drive feedwater pump system of the turbine is gradually reduced, so that the coaxial feedwater pump is switched from the second working mode to the first working mode; (2) when the load of the coaxial drive feedwater pump system of the turbine is reduced to a level sufficient for the electric feedwater pump to provide water to the boiler, the electric feedwater pump is started and increased in speed and incorporated into the coaxial drive feedwater pump system of the turbine, and then the coaxial feedwater pump can be further reduced to the lowest speed and finally stopped; (3) during the start and stop process of the coaxial feedwater pump, the control device mainly controls the opening and closing of the corresponding control valve by energizing and de-energizing the first to sixth solenoid valves, and then controls the filling and emptying of the control oil of the hydraulic coupling, hydraulic torque converter, hydraulic brake, diaphragm coupling and other components, and the engagement and disengagement of the disc brake. The fine adjustment of the hydraulic coupling and the hydraulic torque converter is achieved by the first electro-hydraulic position control device and the second electro-hydraulic position control device.

[0036] In response to the above control ideas, we first introduce the coaxial feedwater pump stop control method provided by an embodiment of the present invention, which is applied to a control device connected to a coaxially driven feedwater pump system of a steam turbine; the coaxially driven feedwater pump system of a steam turbine includes: a steam turbine, a feedwater pump system, a speed control system connected to the steam turbine and the feedwater pump system respectively, and a boiler connected to the feedwater pump system; the steam turbine is used to drive the feedwater pump system; the speed control system is used to adjust the speed of the feedwater pump system; the feedwater pump system is used to supply water to the boiler; the feedwater pump system includes a coaxial feedwater pump and an electric feedwater pump; the electric feedwater pump is connected to the coaxial feedwater pump; the speed control system includes: a torque converter, a disc brake, a hydraulic brake, and a hydraulic coupling; the shaft power of the steam turbine is divided into two shafts after being transmitted through the input end of the speed control system, one shaft is connected to the torque converter and the hydraulic brake in sequence; the other shaft is connected to the hydraulic coupling and the disc brake in sequence.

[0037] Figure 1This is a flow chart of a coaxial feedwater pump stop control method according to an embodiment of the present invention, which is used to realize the load reduction of the steam turbine coaxial drive feedwater pump system and automatically shut down the coaxial feedwater pump safely and stably when the coaxial feedwater pump needs to be shut down for maintenance. Figure 1 As shown, the coaxial water supply pump stop control method provided by the embodiment of the present invention may include:

[0038] S101, acquiring parameters of a steam turbine coaxially driven feedwater pump system in real time; the parameters including load of the steam turbine coaxially driven feedwater pump system and measurement data of measurement points;

[0039] S102, when the coaxial water feed pump fails or needs to be shut down for maintenance, controlling the torque converter and the hydraulic brake in sequence according to the parameters to reduce the speed of the coaxial water feed pump;

[0040] S103. When the rotational speed of the coaxial feedwater pump decreases to less than a first preset rotational speed, calling and executing an electric feedwater pump paralleling program; the electric feedwater pump paralleling program is used to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler;

[0041] S104. After the electric water pump paralleling program is completed, the rotation speed of the coaxial water pump is controlled to be reduced to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters.

[0042] The coaxial feed water pump stop control method provided by the embodiment of the present invention can provide a more accurate and reasonable coaxial feed water pump stop control logic, while ensuring the safe operation of the turbine coaxial drive feed water pump system that uses the turbine coaxial drive feed water pump technology, improving the degree of automation of equipment operation, reducing manual workload, and avoiding errors that may be caused by manual judgment of equipment failures.

[0043] Before introducing the coaxial feedwater pump stop control method, the application scenario of the method is first introduced, namely the control device and the steam turbine coaxial drive feedwater pump system connected to the control device.

[0044] Figure 2 FIG. 1 is a schematic diagram of a steam turbine coaxially driven feedwater pump system according to an embodiment of the present invention. Figure 2 As shown, the steam turbine coaxial drive feedwater pump system mainly includes four subsystems: steam turbine, speed control system, feedwater pump system, boiler (not shown in the figure). In one embodiment, the coaxial feedwater pump stop control method provided by the embodiment of the present invention can be applied to Figure 2The control device 1 is connected to the steam turbine coaxially driven feed water pump system; the speed control system is connected to the steam turbine and the feed water pump system respectively, and is used to adjust the speed of the feed water pump system; the steam turbine is used to drive the feed water pump system; the feed water pump system includes a coaxial feed water pump 9 and an electric feed water pump connected to the coaxial feed water pump; the coaxial feed water pump 9 and the electric feed water pump are used to supply water to the boiler; the speed control system may include: a torque converter 11, a disc brake 8, a hydraulic brake 12, and a hydraulic coupling 6; the shaft power of the steam turbine is divided into two shafts after being transmitted through the input end of the speed control system, one shaft is connected to the torque converter 11 and the hydraulic brake 12 in sequence; the other shaft is connected to the hydraulic coupling 6 and the disc brake 8 in sequence. The working oil in the working oil chamber is pressurized by the working oil pump and then sent to each solenoid valve and electro-hydraulic position controller through the working oil cooler, which is used to control the start and stop and adjustment of the hydraulic coupling, torque converter, etc.; the lubricating oil in the lubricating oil chamber is pressurized by the lubricating oil pump and then sent to the speed control system and each bearing of the coaxial water pump for lubrication and cooling of each bearing.

[0045] In one embodiment, Figure 2 As shown, the speed control system may further include: an input end gear set 3 , a planetary gear set 7 , a lubricating oil pump 4 , a working oil pump 10 , an input shaft, an output shaft, and a diaphragm coupling 21 .

[0046] The steam turbine can be coaxially connected to the input-end gear set 3 through the input shaft. The shaft power of the steam turbine is divided into two shafts after being transmitted through the input-end gear set 3. One shaft is connected to the working oil pump 10, the torque converter 11, the hydraulic brake 12, and the planetary gear set 7 in sequence; the other shaft is connected to the lubricating oil pump 4, the hydraulic coupling 6, the diaphragm coupling 21, the planetary gear set 7, the disc brake 8 and the output shaft in sequence.

[0047] Figure 3 FIG. 1 is a structural diagram of a water supply pump system according to an embodiment of the present invention. Figure 3 As shown, the water feed pump system may also include: an electric door 22 at the inlet of the electric water feed pump, an electric water feed pump front pump 23, an electric water feed pump 24, an electric water feed pump outlet door 25, an electric door 26 after the electric water feed pump recirculation regulating valve, an electric water feed pump recirculation regulating door 27, an electric door 28 before the electric water feed pump recirculation regulating valve, a coaxial water feed pump inlet electric door 29, a coaxial water feed pump front pump 30, a coaxial water feed pump 31, a coaxial water feed pump outlet door 32, an electric door 33 after the coaxial water feed pump recirculation regulating valve, a coaxial water feed pump recirculation regulating door 34, an electric door 35 before the coaxial water feed pump recirculation regulating valve, a deaerator 36 and a water feed main pipe.

[0048] The following combination Figure 2 、 Figure 3From the perspective of the present invention, the output shaft of the speed control system is coaxially connected to the input end of the coaxial feed water pump 31, and the outlet of the deaerator 36 is divided into two paths: one path is connected to the coaxial feed water pump pre-pump 30 and the coaxial feed water pump 31 in sequence through the coaxial feed water pump inlet electric door 29, and the outlet of the coaxial feed water pump 31 is divided into two paths, one path passes through the coaxial feed water pump recirculation regulating valve front electric door 35, the coaxial feed water pump recirculation regulating valve 34 and the coaxial feed water pump recirculation regulating valve rear electric door 33 and then returns to the deaerator 36, and the other path passes through the coaxial feed water pump outlet door 32 and the electric feed water pump 24 The outlet water supply is merged and then goes to the heater; the other outlet of the deaerator 36 is connected to the electric water supply pump pre-pump 23 and the electric water supply pump 24 in sequence through the electric water supply pump inlet electric door 22, and the outlet of the electric water supply pump 24 is divided into two routes, one route passes through the electric water supply pump recirculation regulating valve front electric door 28, the electric water supply pump recirculation regulating valve 27 and the electric water supply pump recirculation regulating valve rear electric door 26 and then returns to the deaerator 36, and the other route passes through the electric water supply pump outlet door 25 and merges with the outlet of the coaxial water supply pump 31 through the water supply main pipe and then goes to the heater.

[0049] like Figure 2 As shown, in one embodiment, the speed control system may also include a first solenoid valve 13 connected to the disc brake 8, a second solenoid valve 15 and a third solenoid valve 16 connected to the hydraulic coupling 6, a fourth solenoid valve 17 connected to the diaphragm coupling 21, a fifth solenoid valve 18 connected to the torque converter 11 and a sixth solenoid valve 20 connected to the hydraulic brake 12.

[0050] It should be noted that since the thermal power plant unit also includes other equipment in addition to the turbine coaxial drive feed water pump system, the parameters in S101 can also include the load of the thermal power plant unit, and then the speed of the coaxial feed water pump is controlled according to the load of the thermal power plant unit.

[0051] In one embodiment, the measurement data of the measurement points may specifically include: pressure data of the pressure measurement point, speed data of the speed measurement point, and opening data of the valve measurement point.

[0052] In this embodiment, the pressure measuring points may include: one or any combination of the coaxial water supply pump outlet water supply, the electric water supply pump outlet water supply, and the water supply main pipe water supply; the speed measuring points may include: one or any combination of the coaxial water supply pump and the electric water supply pump; the valve measuring points may include: the electric water supply pump inlet electric door, the electric water supply pump outlet electric door, the electric water supply pump recirculation regulating valve, the front and rear electric doors of the electric water supply pump recirculation regulating valve, the coaxial water supply pump recirculation regulating valve, the scoop tube of the hydraulic coupling, the guide vane of the torque converter, the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the sixth solenoid valve, or any combination.

[0053] Specifically, if Figure 2As shown, the control device 1 may include a first electro-hydraulic position control device 5 and a second electro-hydraulic position control device 19. The control device 1 may call the first electro-hydraulic position control device via a signal cable to control the guide vane opening of the hydraulic coupler; the control device may call the second electro-hydraulic position control device via a signal cable to control the guide vane opening of the torque converter.

[0054] The control device 1 collects measurement data from measurement points in the turbine coaxially driven feedwater pump system via signal cables. This data may include: input shaft speed R1, speed control system superimposed speed R2, coaxial feedwater pump speed R3, scoop pipe opening of the hydraulic coupling 6, guide vane opening or position of the torque converter 11, control oil pressure P1 of the diaphragm coupling 21, lubricating oil pressure P2 in the speed control system, control oil pressure P3 of the torque converter 11, the on / off status of the disc brake 8, and the on / off status of the hydraulic brake 12. The control device 1 can also control valves or devices such as the first electro-hydraulic position control device 5, the first solenoid valve 13, the second solenoid valve 15, the third solenoid valve 16, the fourth solenoid valve 17, the fifth solenoid valve 18, the second electro-hydraulic position control device 19, and the sixth solenoid valve 20 via signal cables. The sampling scan period of the control device 1 is typically 200ms.

[0055] like Figure 3 As shown, the control device 1 can collect measurement data of the deaerator liquid level H1, the coaxial water supply pump outlet water pressure P4, the electric water supply pump outlet pressure P5, the water supply main pipe pressure P6, the electric water supply pump speed R4 and other measuring points through the signal cable. The control device 1 can also control the start and stop of the coaxial water supply pump 31 and the electric water supply pump 24, and the switching of related electric valves and pneumatic control valves through the signal cable; the sampling scan period of the control device 1 is generally 200ms.

[0056] It should be noted that the measuring points of the control device 1 in the coaxial water supply pump stop control method are different from the measuring points of the control device 1 in the coaxial water supply pump start-up control method. In one embodiment, the pressure measuring points in the coaxial water supply pump stop control method may include: one or any combination of the coaxial water supply pump outlet water supply, the electric water supply pump outlet water supply, and the water supply main pipe water supply; the speed measuring points may include: one or any combination of the coaxial water supply pump and the electric water supply pump; the valve measuring points include: the electric water supply pump inlet electric door, the electric water supply pump outlet electric door, the electric water supply pump recirculation regulating valve, the front and rear electric doors of the electric water supply pump recirculation regulating valve, the coaxial water supply pump recirculation regulating valve, the scoop tube of the hydraulic coupling, the guide vane of the torque converter, the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the sixth solenoid valve, or any combination.

[0057] Figure 4 This is a flowchart of a specific example of a coaxial water pump stop control method according to an embodiment of the present invention, with reference to Figure 4As shown, in some embodiments, the coaxial water supply pump stop control method may include the following steps:

[0058] S401, the speed of the coaxial feed water pump decreases as the load of the steam turbine coaxial drive feed water pump system decreases.

[0059] When the coaxial feedwater pump fails or needs to be shut down for maintenance, the turbine coaxial drive feedwater pump system begins to reduce the load, and the coaxial feedwater pump is controlled by the control device and the speed is reduced accordingly.

[0060] S402. Determine whether the guide vane opening of the torque converter satisfies the requirement of <s.

[0061] When the coaxial water feed pump reduces its speed under high load conditions, the coaxial water feed pump is in the second working mode, that is, the guide vane opening is controlled by the second electro-hydraulic position control device of the torque converter to gradually decrease. When the guide vane opening is closed to a certain value (s), the torque converter working mode can be exited.

[0062] The value of the constant s is determined according to the actual situation of the steam turbine coaxially driven feedwater pump system and equipment. For example, in a certain embodiment, s is 17%.

[0063] Before using the coaxial water supply pump stop control method to stop the coaxial water supply pump, the coaxial water supply pump also goes through a startup stage. During the startup and stop process of the coaxial water supply pump, the speed control system switches between the first working mode and the second working mode respectively. The first working mode and the second working mode are introduced below.

[0064] During the startup and speed-up phase of the coaxial water supply pump, its speed is precisely controlled by the first electro-hydraulic position control device. At this time, the speed control system operates in the first working mode, that is, the hydraulic coupling working mode. The status of each solenoid valve in the speed control system is shown in Table 1 below:

[0065] Table 1

[0066] Solenoid valve status Corresponding functional status The second solenoid valve 46.6 is energized Fluid coupling bypass valve open The third solenoid valve 46.1 is energized Fill the hydraulic coupling with control oil The fifth solenoid valve 46.4 loses power Drain the torque converter control oil The sixth solenoid valve 46.5 is energized Filling hydraulic brake control oil The fourth solenoid valve 46.2 loses power Disengagement of diaphragm coupling The first solenoid valve 90.2 loses power Disc brake is disengaged

[0067] When the coaxial feedwater pump's speed is low, power is transmitted directly from the planetary gear set via the hydraulic coupling. Adjusting the hydraulic coupling's scoop opening alone adjusts the oil level, and thus the pump's speed. During this period, the solenoid valves maintain their states as they did when the speed control system was started.

[0068] Figure 5 FIG. 1 is a schematic diagram of a first working mode of a speed control system according to an embodiment of the present invention. Figure 5As shown, under this operating condition, power is transmitted to the output shaft solely through the hydraulic coupling. The control device adjusts the opening of the hydraulic coupling's scoop tube to control the speed of the coaxial water pump. This operating mode allows for a speed adjustment range of approximately 0-80%. The torque converter is drained and inoperative. The hydraulic brake is filled with oil, generating a reverse torque on the planetary gears. This maintains a low speed, preventing rust and friction marks.

[0069] When the coaxial feedwater pump cannot meet the boiler's water supply demand, the speed control system switches from the first operating mode to the second operating mode, namely the torque converter mode. At this time, the control device de-energizes and closes the third solenoid valve 46.1, energizes and opens the fifth solenoid valve 46.4, de-energizes and closes the sixth solenoid valve 46.5, and energizes and opens the fourth solenoid valve 46.2, thereby draining the hydraulic coupling working oil, injecting the diaphragm coupling, filling the torque converter working oil, and draining the hydraulic brake working oil. At this time, the status of each solenoid valve in the speed control system is shown in Table 2 below:

[0070] Table 2

[0071] Solenoid valve status Corresponding functional status The second solenoid valve 46.6 is energized Fluid coupling bypass valve open The third solenoid valve 46.1 loses power Drain the hydraulic coupling control oil The fifth solenoid valve 46.4 is energized Filling torque converter control oil The sixth solenoid valve 46.5 loses power Draining the hydraulic brake control oil The fourth solenoid valve 46.2 is energized Diaphragm coupling investment The first solenoid valve 90.2 loses power Disc brake is disengaged

[0072] Figure 6 FIG. 1 is a schematic diagram of a second working mode of a speed control system according to an embodiment of the present invention. Figure 6 As shown, in this state, the front and rear rotors of the hydraulic coupling are mechanically coupled via a diaphragm coupling, and the hydraulic coupling no longer performs a regulating function. Simultaneously, the hydraulic brake is vented, disengaging the brake position. The coaxial feedwater pump speed is now regulated by the torque converter's second electro-hydraulic position control device. By varying the position of the torque converter's guide vanes, the torque output to the driven shaft is adjusted and superimposed via gears on the planetary gear system's output shaft, i.e., the feedwater pump's output shaft.

[0073] It should be pointed out that as the load of the turbine coaxially driven feed water pump system rises and falls, the boiler feed water changes continuously. The control method proposed in the present invention can ensure that the speed control system can switch quickly and freely between these two working modes. The entire switching process is fast and stable, without dwell time, which can ensure stable and continuous changes in the boiler water supply.

[0074] Returning to S402, when the coaxial feedwater pump is reduced in speed under high load conditions, it enters the second operating mode, where the second electro-hydraulic position control device gradually decreases the guide vane opening of the torque converter. The second operating mode is exited only after the guide vane opening reaches a certain value, s.

[0075] S403, open the sixth solenoid valve 46.5, fill the hydraulic brake with oil, and continue to reduce the speed of the coaxial water pump.

[0076] In one embodiment, S102 may include: when the load of the steam turbine coaxially driven feedwater pump system is higher than a preset load, controlling the guide vane opening of the torque converter to be closed to a first preset opening, controlling the sixth solenoid valve to open, and controlling the speed of the coaxial feedwater pump to be reduced through the hydraulic brake.

[0077] When the guide vanes of the torque converter are closed to a value less than the first preset opening s, the control device energizes and opens the sixth solenoid valve 46.5, thereby filling the hydraulic brake with oil to start braking. At the same time, the speed of the coaxial water pump continues to decrease.

[0078] S404: After the rotational speed R3 of the coaxial water supply pump drops to the second preset rotational speed t, the fourth solenoid valve 46.2 is closed, the third solenoid valve 46.1 is opened, and the sixth solenoid valve 46.5 is closed.

[0079] In one embodiment, S102 may further include: when the speed of the coaxial water supply pump drops to a second preset speed, controlling the fourth solenoid valve to close, the third solenoid valve to open, and the sixth solenoid valve to close in sequence according to the parameters.

[0080] When the speed of the coaxial water pump continues to decrease to a certain level, the control device controls the fourth solenoid valve 46.2 to be de-energized and closed to disengage the diaphragm coupling, controls the third solenoid valve 46.1 to be energized and open to fill the hydraulic coupling control oil, and controls the sixth solenoid valve 46.5 to be de-energized and closed to drain the torque converter control oil.

[0081] The value of the second preset speed t is determined according to the actual situation of the steam turbine coaxially driven feedwater pump system and equipment. For example, in a certain embodiment, t is 4150 r / min.

[0082] S405. The coaxial feedwater pump switches to the first working mode and continues to reduce speed as the load of the steam turbine coaxial drive feedwater pump system decreases.

[0083] In one embodiment, S102 may further include: controlling the rotation speed of the coaxial water pump to decrease by adjusting the opening of the scoop pipe of the hydraulic coupling according to the parameters.

[0084] At this point, the coaxial feed water pump switches to the first working mode (hydraulic coupling working mode), and the control device adjusts the opening of the hydraulic coupling scoop tube through the first electro-hydraulic position control device, thereby controlling the speed of the coaxial feed water pump to continue to decrease as the load of the turbine coaxial drive feed water pump system decreases.

[0085] S406. Determine whether the coaxial water pump speed R3 < u (first preset speed) is satisfied?

[0086] When the load of the steam turbine coaxial driven feed water pump system continues to decrease, the speed of the coaxial feed water pump continues to decrease until the electric feed water pump is sufficient to meet the boiler water supply volume and water supply parameter requirements. The electric feed water pump can be started and incorporated into the feed water system.

[0087] The value of the constant u is determined according to the actual situation of the steam turbine coaxially driven feedwater pump system and equipment. For example, in a certain embodiment, u is 2000 r / min.

[0088] S407, start the "electric water supply pump parallel pumping program".

[0089] In this embodiment, S406-S407 are equivalent to S103, that is, when the speed of the coaxial water feed pump is reduced to less than the first preset speed u, the electric water feed pump parallel pump program is called and executed; the electric water feed pump parallel pump program is used to control the electric water feed pump to replace the coaxial water feed pump to supply water to the boiler.

[0090] When the conditions for parallel operation of the electric feed water pumps are met, start the "automatic parallel operation program for electric feed water pumps" to integrate the electric feed water pumps into the steam turbine coaxial drive feed water pump system. At the same time, withdraw the coaxial feed water pumps from the steam turbine coaxial drive feed water pump system.

[0091] S408. The coaxial water supply pump continues to reduce its speed, and the opening of the hydraulic coupling scoop tube is set to v.

[0092] In one embodiment, S104 may include: after the electric water pump parallel pumping program is executed, adjusting the scoop pipe opening of the hydraulic coupling to a second preset opening according to the parameter.

[0093] After the outlet door of the coaxial water supply pump is fully closed and completely exits the water supply system, the opening of the hydraulic coupling scoop tube is set to a smaller value v (the second preset opening) to prepare for stopping the coaxial water supply pump.

[0094] The value of the second preset opening v is determined according to the actual situation of the steam turbine coaxially driven feedwater pump system and equipment. For example, in a certain embodiment, v is 5%.

[0095] S409, close the third solenoid valve 46.1, open the first solenoid valve 90.2, and stop the coaxial water pump.

[0096] In one embodiment, S104 may further include: sequentially controlling the third solenoid valve to close and the first solenoid valve to open, and controlling the rotation speed of the coaxial water pump to decrease to zero through the disc brake.

[0097] After the scoop tube of the hydraulic coupling is closed, the speed of the coaxial water pump also drops to a very low level. At this time, the control device de-energizes and closes the third solenoid valve 46.1, thereby draining the control oil of the hydraulic coupling. At the same time, the first solenoid valve 90.2 is energized and opened, and the disc brake is engaged to brake the coaxial water pump to 0 speed. At this point, the coaxial water pump is successfully shut down.

[0098] In order to achieve precise automatic control of the entire process of the coaxial feedwater pump from full load output to exiting the turbine coaxial drive feedwater pump system, and to ensure that the electric feedwater pump can be quickly and stably integrated into the turbine coaxial drive feedwater pump system during startup, and replace the coaxial feedwater pump to supply water to the boiler, in one embodiment, the electric feedwater pump parallel pump procedure may include: when the electric feedwater pump is filled with water, the electric feedwater pump inlet electric door is in a fully open state, and the electric feedwater pump outlet electric door is in a fully closed state, controlling the electric feedwater pump recirculation regulating valve and the front and rear electric doors of the electric feedwater pump recirculation regulating valve to be fully open; controlling the coaxial feedwater pump recirculation regulating valve and the electric feedwater pump recirculation regulating valve to be in the automatic position; the coaxial feedwater pump recirculation regulating valve is placed in the automatic position, indicating that: adjusting its own opening according to the inlet feedwater flow of the coaxial feedwater pump; the electric feedwater pump recirculation regulating valve is placed in the automatic position, indicating: adjusting its own opening according to the electric The inlet water flow of the water supply pump adjusts its own opening; the speed of the electric water supply pump is controlled to increase at a first preset rate until the difference between the outlet water supply pressure of the electric water supply pump and the outlet water supply pressure of the coaxial water supply pump is less than the first preset difference and the difference between the outlet water supply pressure of the electric water supply pump and the pressure of the main water supply pipe is less than the second preset difference; the electric door of the electric water supply pump outlet is controlled to open to full open at the second preset rate; the speed of the electric water supply pump is controlled to increase by a fourth preset speed and the speed of the coaxial water supply pump is controlled to decrease by a fifth preset speed; if the difference between the outlet water supply pressure of the electric water supply pump and the outlet water supply pressure of the coaxial water supply pump is greater than the third preset difference, and the difference between the pressure of the main water supply pipe and the outlet water supply pressure of the coaxial water supply pump is greater than the fourth preset difference, the electric door of the coaxial water supply pump outlet is controlled to close at the third preset rate; when the electric door of the coaxial water supply pump outlet is fully closed, the coaxial water supply pump is controlled to stop running.

[0099] Figure 7 This is a flowchart of a specific example of an electric water supply pump parallel pumping program in an embodiment of the present invention, with reference to Figure 7 As shown, in some embodiments, the electric water pump paralleling procedure may include the following steps:

[0100] S701. Check that the electric water supply pump is fully filled with water, the electric door of the electric water supply pump inlet is fully open, and the electric door of the electric water supply pump outlet is fully closed. Open the electric water supply pump recirculation regulating valve and the electric doors before and after the electric water supply pump recirculation regulating valve.

[0101] First, check that the electric water supply pump has been filled with water. At the same time, its inlet electric door is fully open and the outlet electric door is fully closed. Also, fully open the electric water supply pump recirculation regulating valve and its front and rear electric doors to prepare for starting the electric pump.

[0102] S702. Place the coaxial water supply pump recirculation regulating valve and the electric water supply pump recirculation regulating valve in the automatic position, start the electric water supply pump, and slowly increase the speed.

[0103] The recirculation regulating valves of the coaxial water supply pump and the electric water supply pump are placed in the automatic position. The opening of the regulating valve can be automatically adjusted according to the water supply flow rate at the pump inlet to prevent the electric water supply pump from overloading or the coaxial water supply pump from being blocked during the parallel pumping process; the control device controls the electric water supply pump to slowly increase the speed at a first preset rate.

[0104] S703. Determine whether the conditions |P5-P4| < c, |P5-P6| < d are met.

[0105] The electric water feed pump slowly increases speed at a first preset rate until the outlet water feed pressure P5 of the electric water feed pump is balanced with the outlet water feed pressure P4 of the coaxial water feed pump and the main water feed pipe pressure P6 (the judgment condition is ︱P5-P4︱<c, ︱P5-P6︱<d), to prevent excessive impact on the water feed pipe or large disturbance to the water supply to the boiler when the outlet door of the electric water feed pump is opened.

[0106] Among them, the values ​​of the first preset difference c and the second preset difference d are determined according to the actual situation of the steam turbine coaxial drive feed water pump system and equipment. For example, in a certain embodiment, c is 0.1 MPa and d is 0.1 MPa.

[0107] S704. Slowly open the electric door at the outlet of the electric water supply pump at a second preset rate, where the second preset rate is e.

[0108] After the conditions of S703 are met, the electric door at the outlet of the electric water supply pump can be slowly opened at a second preset rate e to put the electric water supply pump into the water supply system.

[0109] The value of the second preset rate e is determined according to the actual situation of the steam turbine coaxially driven feedwater pump system and equipment. For example, in a certain embodiment, e is 2% / s.

[0110] S705. Determine whether the electric door at the outlet of the electric water pump is fully open?

[0111] Only when the electric gate of the electric water supply pump outlet is fully opened, that is, the electric water supply pump is fully put into the water supply system, can the electric pump speed be further increased. Otherwise, it is easy to cause the electric water supply pump to stagnate and cause erosion of the outlet gate valve core.

[0112] S706. On the original basis, the electric water supply pump speed R4 is increased by a fourth preset speed f, and the coaxial water supply pump speed R3 is reduced by a fifth preset speed g.

[0113] After the electric water supply pump is fully put into the water supply system, the speed R4 of the electric water supply pump can be quickly increased to the fourth preset speed f, and at the same time the speed R3 of the coaxial water supply pump can be reduced to the fifth preset speed g, so as to ensure that the water supply at the outlet of the electric water supply pump can be quickly pushed into the water supply main pipe, and the coaxial water supply pump can quickly exit after reducing the speed; in this process, the recirculation regulating valve of the coaxial water supply pump will gradually open until it is fully open, and the recirculation regulating valve of the electric water supply pump will gradually close until it is fully closed.

[0114] The values ​​of the fixed values ​​f and g are determined according to the actual conditions of the steam turbine coaxially driven feedwater pump system and equipment. For example, in a certain embodiment, f is 200 r / min and g is 200 r / min.

[0115] S707: Determine whether the conditions P6-P4>h, P5-P4>i are met?

[0116] The outlet door of the coaxial feed water pump can only be closed when it is determined that the coaxial feed water pump is completely no longer responsible for the boiler water supply task. The judgment condition is that the outlet water supply pressure of the electric feed water pump and the main water supply pipe pressure are both much greater than the outlet water supply pressure of the coaxial feed water pump, that is, P6-P4>h, P5-P4>i.

[0117] Among them, the values ​​of the fourth preset difference h and the third preset difference i are determined according to the actual situation of the steam turbine coaxial drive water supply pump system and equipment. For example, in a certain embodiment, h is 2MPa and i is 2MPa.

[0118] S708. Slowly close the electric door at the outlet of the coaxial water pump at a third preset rate, where the third preset rate is j.

[0119] When it is determined that the coaxial feed water pump is completely unable to bear the task of boiler water supply, the coaxial feed water pump outlet electric door can be slowly closed at a third preset rate j to prevent the coaxial feed water pump from withdrawing and causing disturbance to the boiler water supply.

[0120] The value of the constant j is determined according to the actual situation of the steam turbine coaxially driven feedwater pump system and equipment. For example, in a certain embodiment, j is 3% / s.

[0121] S709. When the electric door at the outlet of the coaxial water pump is fully closed, the pumping is completed.

[0122] After the electric door of the coaxial feed water pump outlet is fully closed, the boiler water supply task is undertaken solely by the electric feed water pump, and the entire pump paralleling process is completed.

[0123] In summary, compared with the prior art, the embodiments of the present invention obtain parameters of the steam turbine coaxially driven feedwater pump system in real time; the parameters include the load of the steam turbine coaxially driven feedwater pump system and the measurement data of the measuring points; when the coaxial feedwater pump fails or needs to be shut down for maintenance, the speed of the coaxial feedwater pump is controlled to be reduced by controlling the torque converter and the hydraulic brake in sequence according to the parameters; when the speed of the coaxial feedwater pump is reduced to less than the first preset speed, the electric feedwater pump parallel program is called and executed; the electric feedwater pump parallel program is used to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler; after the electric feedwater pump parallel program is executed, the speed of the coaxial feedwater pump is controlled to be reduced to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters, which can provide a more accurate and reasonable coaxial feedwater pump stop control logic, while ensuring the safe operation of the steam turbine coaxially driven feedwater pump system that applies the steam turbine coaxially driven feedwater pump technology, while improving the degree of automation of equipment operation, reducing manual workload, and avoiding errors that may be caused by manual judgment of equipment failures.

[0124] The present invention also provides a coaxial water supply pump stop control device, as described in the following embodiments. Since the principle of the device to solve the problem is similar to that of the coaxial water supply pump stop control method, the implementation of the device can refer to the implementation of the coaxial water supply pump stop control method, and the repeated parts will not be repeated.

[0125] An embodiment of the present invention also provides a coaxial feed water pump stop control device, which is used to provide more accurate and reasonable coaxial feed water pump stop control logic, while ensuring the safe operation of the turbine coaxial drive feed water pump system that uses turbine coaxial drive feed water pump technology, improving the degree of automation of equipment operation, reducing manual workload, and avoiding errors that may be caused by manual judgment of equipment failures.

[0126] The coaxial feedwater pump stop control device is applied to a control device connected to the coaxially driven feedwater pump system of the turbine; the coaxially driven feedwater pump system of the turbine includes: a steam turbine, a feedwater pump system, a speed control system connected to the steam turbine and the feedwater pump system respectively, and a boiler connected to the feedwater pump system; the steam turbine is used to drive the feedwater pump system; the speed control system is used to adjust the speed of the feedwater pump system; the feedwater pump system is used to supply water to the boiler; the feedwater pump system includes a coaxial feedwater pump and an electric feedwater pump; the electric feedwater pump is connected to the coaxial feedwater pump; the speed control system includes: a torque converter, a disc brake, a hydraulic brake, and a hydraulic coupling; the shaft power of the turbine is divided into two shafts after being transmitted through the input end of the speed control system, one shaft is connected to the torque converter and the hydraulic brake in sequence; the other shaft is connected to the hydraulic coupling and the disc brake in sequence.

[0127] Figure 8 FIG. 1 is a structural block diagram of a coaxial water pump stop control device according to an embodiment of the present invention. Figure 8As shown, the present invention provides a coaxial water pump stop control device comprising:

[0128] An acquisition module 801 is used to acquire parameters of a steam turbine coaxially driven feedwater pump system in real time; the parameters include loads of the steam turbine coaxially driven feedwater pump system and measurement data of measurement points;

[0129] The first control module 802 is configured to control the torque converter, the hydraulic brake, and the hydraulic coupling in sequence to reduce the speed of the coaxial water feed pump when the coaxial water feed pump fails or needs to be shut down for maintenance according to the parameters;

[0130] The pump paralleling module 803 is configured to call and execute an electric feedwater pump paralleling program when the speed of the coaxial feedwater pump decreases to less than a first preset speed; the electric feedwater pump paralleling program is configured to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler;

[0131] The second control module 804 is used to control the speed of the coaxial water pump to be reduced to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters after the electric water pump parallel pump program is executed.

[0132] In one embodiment, the speed control system further includes: an input end gear set, a planetary gear set, a lubricating oil pump, a working oil pump, an input shaft, an output shaft, and a diaphragm coupling;

[0133] The feed water pump system also includes: a coaxial feed water pump pre-pump, an electric feed water pump pre-pump, a deaerator, a coaxial feed water pump inlet electric door, a coaxial feed water pump outlet electric door, a coaxial feed water pump recirculation regulating valve, front and rear electric doors of the coaxial feed water pump recirculation regulating valve, an electric feed water pump inlet electric door, an electric feed water pump outlet electric door, an electric feed water pump recirculation regulating valve, front and rear electric doors of the electric feed water pump recirculation regulating valve, and a water supply main pipe;

[0134] The steam turbine is coaxially connected to the input end gear set through the input shaft. The shaft power of the steam turbine is divided into two shafts after being transmitted by the input end gear set. One shaft is connected to the working oil pump, hydraulic torque converter, hydraulic brake, and planetary gear set in sequence; the other shaft is connected to the lubricating oil pump, hydraulic coupling, diaphragm coupling, planetary gear set, disc brake and output shaft in sequence.

[0135] The output shaft of the speed control system is coaxially connected to the input end of the coaxial feed water pump, and the deaerator outlet is divided into two routes: one route is connected to the coaxial feed water pump pre-pump and the coaxial feed water pump in sequence through the coaxial feed water pump inlet electric door, and the coaxial feed water pump outlet is divided into two routes, one route passes through the coaxial feed water pump recirculation regulating valve front electric door, the coaxial feed water pump recirculation regulating valve and the coaxial feed water pump recirculation regulating valve rear electric door and then returns to the deaerator, and the other route passes through the coaxial feed water pump outlet door and merges with the electric feed water pump outlet feed water before going to the heater; the other route of the deaerator outlet is connected to the electric feed water pump pre-pump and the electric feed water pump through the electric feed water pump inlet electric door in sequence, and the electric feed water pump outlet is divided into two routes, one route passes through the electric feed water pump recirculation regulating valve front electric door, the electric feed water pump recirculation regulating valve and the electric feed water pump recirculation regulating valve rear electric door and then returns to the deaerator, and the other route passes through the electric feed water pump outlet door and merges with the coaxial feed water pump outlet through the feed water main pipe and then goes to the heater.

[0136] In one embodiment, the speed control system also includes a first solenoid valve connected to the disc brake, a second solenoid valve and a third solenoid valve connected to the hydraulic coupling, a fourth solenoid valve connected to the diaphragm coupling, a fifth solenoid valve connected to the torque converter, and a sixth solenoid valve connected to the hydraulic brake.

[0137] In one embodiment, the measurement data of the measuring points specifically include: pressure data of the pressure measuring point, speed data of the speed measuring point, and opening data of the valve measuring point.

[0138] In one embodiment, the pressure measurement points include: water supply from the outlet of a coaxial water pump, water supply from the outlet of an electric water pump, and water supply from a main water pipe, or any combination thereof;

[0139] The speed measurement points include: one or any combination of coaxial water feed pump and electric water feed pump;

[0140] The valve measurement points include: electric feed water pump inlet electric door, electric feed water pump outlet electric door, electric feed water pump recirculation regulating valve, electric feed water pump recirculation regulating valve front and rear electric doors, coaxial feed water pump recirculation regulating valve, hydraulic coupling scoop tube, hydraulic torque converter guide vane, the first solenoid valve, the third solenoid valve, the fourth solenoid valve, the sixth solenoid valve, or any combination thereof.

[0141] In one embodiment, the first control module 802 is specifically configured to:

[0142] When the load of the steam turbine coaxially driven feedwater pump system is higher than a preset load, the guide vane opening of the torque converter is controlled to be closed to a first preset opening according to the parameters, the sixth solenoid valve is controlled to be opened, and the speed of the coaxial feedwater pump is controlled to be reduced by the hydraulic brake;

[0143] When the speed of the coaxial water pump drops to the second preset speed, the fourth solenoid valve is controlled to close, the third solenoid valve is controlled to open, and the sixth solenoid valve is controlled to close in sequence according to the parameters;

[0144] According to the parameters, the speed of the coaxial water feed pump is controlled to decrease by adjusting the opening of the scoop tube of the hydraulic coupling.

[0145] In one embodiment, the second control module 804 is specifically configured to:

[0146] When the electric water pump parallel pump program is completed, the scoop tube opening of the hydraulic coupling is adjusted to the second preset opening according to the parameters, the third solenoid valve is controlled to close and the first solenoid valve is controlled to open in turn, and the speed of the coaxial water pump is controlled to be reduced to zero through the disc brake.

[0147] In one embodiment, the control device may include: a first electro-hydraulic position control device and a second electro-hydraulic position control device; the control device calls the first electro-hydraulic position control device through a signal cable to control the guide vane opening of the hydraulic coupling; the control device calls the second electro-hydraulic position control device through a signal cable to control the guide vane opening of the torque converter.

[0148] In one embodiment, the electric feedwater pump paralleling procedure includes:

[0149] When the electric water supply pump has finished filling water, the electric door of the electric water supply pump inlet is in the fully open state, and the electric door of the electric water supply pump outlet is in the fully closed state, the electric water supply pump recirculation regulating valve and the electric doors before and after the electric water supply pump recirculation regulating valve are controlled to fully open;

[0150] Control the recirculation regulating valve of the coaxial water feed pump and the recirculation regulating valve of the electric water feed pump to the automatic position; the recirculation regulating valve of the coaxial water feed pump is placed in the automatic position, which means: its opening is adjusted according to the inlet water flow of the coaxial water feed pump; the recirculation regulating valve of the electric water feed pump is placed in the automatic position, which means: its opening is adjusted according to the inlet water flow of the electric water feed pump;

[0151] Controlling the speed of the electric water supply pump to increase at a first preset rate until the difference between the water supply pressure at the outlet of the electric water supply pump and the water supply pressure at the outlet of the coaxial water supply pump is less than the first preset difference and the difference between the water supply pressure at the outlet of the electric water supply pump and the pressure of the water supply main pipe is less than the second preset difference;

[0152] Controlling the electric door of the electric water supply pump outlet to open to full open at a second preset rate;

[0153] Control the electric water supply pump to increase the speed to a fourth preset speed and the coaxial water supply pump to decrease the speed to a fifth preset speed;

[0154] If the difference between the outlet water pressure of the electric water supply pump and the outlet water pressure of the coaxial water supply pump is greater than the third preset difference, and the difference between the main water supply pipe pressure and the outlet water pressure of the coaxial water supply pump is greater than the fourth preset difference, the outlet electric door of the coaxial water supply pump is controlled to close at the third preset rate;

[0155] When the electric door at the outlet of the coaxial water supply pump is fully closed, the coaxial water supply pump is controlled to stop running.

[0156] It should be noted that while the detailed description above describes several modules of the coaxial feedwater pump stop control device, this division is merely exemplary and not mandatory. In practice, depending on embodiments of the present invention, the features and functions of two or more modules described above may be embodied in a single module. Conversely, the features and functions of a single module described above may be further divided and embodied by multiple modules.

[0157] Based on the above invention concept, Figure 9 As shown, the present invention also proposes a computer device 900, including a memory 901, a processor 902 and a computer program 903 stored in the memory 901 and executable on the processor 902, wherein the processor 902 implements the aforementioned coaxial water supply pump stop control method when executing the computer program 903.

[0158] Based on the aforementioned inventive concept, the present invention proposes a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the aforementioned coaxial water supply pump stop control method is implemented.

[0159] Based on the aforementioned inventive concept, the present invention proposes a computer program product, which includes a computer program. When the computer program is executed by a processor, a coaxial water supply pump stop control method is implemented.

[0160] The embodiment of the present invention automatically controls the process of stopping the coaxial water feed pump from full load output to exiting the water feed system operation, thereby achieving close and precise coordination of various components such as the coaxial water feed pump, the speed control system hydraulic coupling, the hydraulic torque converter, the hydraulic brake, and the diaphragm coupling, thereby ensuring automatic and precise control of the entire process of switching between the first working mode and the second working mode of the speed control system. By applying the technical solution of the present invention, the cumbersome steps and possible misoperations of the operating personnel can be greatly reduced, and the risk of boiler water shortage during the shutdown of the coaxial water feed pump due to a fault can be reduced, thereby significantly improving the automation level of the turbine coaxial drive water feed pump system, and ensuring the safe and stable operation of the turbine coaxial drive water feed pump.

[0161] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0162] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts 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, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0163] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0164] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0165] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A coaxial water pump stop control method, characterized in that: Used in control devices connected to the steam turbine coaxial drive feedwater pump system; The steam turbine coaxially driven feedwater pump system comprises: a steam turbine, a feedwater pump system, a speed regulating system connected to the steam turbine and the feedwater pump system respectively, and a boiler connected to the feedwater pump system; the steam turbine is used to drive the feedwater pump system; the speed regulating system is used to regulate the speed of the feedwater pump system; the feedwater pump system is used to supply water to the boiler; the feedwater pump system comprises a coaxial feedwater pump and an electric feedwater pump; the electric feedwater pump is connected to the coaxial feedwater pump; the speed regulating system comprises: a hydraulic torque converter, a disc brake, a hydraulic brake, and a hydraulic coupling; the shaft power of the steam turbine is transmitted through the input end of the speed regulating system and then divided into two shafts, one shaft is connected to the hydraulic torque converter and the hydraulic brake in sequence; the other shaft is connected to the hydraulic coupling and the disc brake in sequence; The method comprises: Real-time acquisition of parameters of the steam turbine coaxially driven feedwater pump system; the parameters include load of the steam turbine coaxially driven feedwater pump system and measurement data of measuring points; When the coaxial water feed pump fails or needs to be shut down for maintenance, the speed of the coaxial water feed pump is reduced by controlling the hydraulic torque converter, the hydraulic brake, and the hydraulic coupling in sequence according to the parameters; When the speed of the coaxial feedwater pump decreases to less than the first preset speed, the electric feedwater pump parallel program is called and executed; the electric feedwater pump parallel program is used to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler; When the electric water pump paralleling program is completed, the speed of the coaxial water pump is controlled to be reduced to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters.

2. The method according to claim 1, wherein The speed control system further includes: an input end gear set, a planetary gear set, a lubricating oil pump, a working oil pump, an input shaft, an output shaft, and a diaphragm coupling; The feed water pump system also includes: a coaxial feed water pump pre-pump, an electric feed water pump pre-pump, a deaerator, a coaxial feed water pump inlet electric door, a coaxial feed water pump outlet electric door, a coaxial feed water pump recirculation regulating valve, front and rear electric doors of the coaxial feed water pump recirculation regulating valve, an electric feed water pump inlet electric door, an electric feed water pump outlet electric door, an electric feed water pump recirculation regulating valve, front and rear electric doors of the electric feed water pump recirculation regulating valve, and a water supply main pipe; The steam turbine is coaxially connected to the input end gear set through the input shaft. The shaft power of the steam turbine is divided into two shafts after being transmitted by the input end gear set. One shaft is connected to the working oil pump, hydraulic torque converter, hydraulic brake, and planetary gear set in sequence; the other shaft is connected to the lubricating oil pump, hydraulic coupling, diaphragm coupling, planetary gear set, disc brake and output shaft in sequence. The output shaft of the speed control system is coaxially connected to the input end of the coaxial feed water pump, and the deaerator outlet is divided into two routes: one route is connected to the coaxial feed water pump pre-pump and the coaxial feed water pump in sequence through the coaxial feed water pump inlet electric door, and the coaxial feed water pump outlet is divided into two routes, one route passes through the coaxial feed water pump recirculation regulating valve front electric door, the coaxial feed water pump recirculation regulating valve and the coaxial feed water pump recirculation regulating valve rear electric door and then returns to the deaerator, and the other route passes through the coaxial feed water pump outlet door and merges with the electric feed water pump outlet feed water before going to the heater; the other route of the deaerator outlet is connected to the electric feed water pump pre-pump and the electric feed water pump through the electric feed water pump inlet electric door in sequence, and the electric feed water pump outlet is divided into two routes, one route passes through the electric feed water pump recirculation regulating valve front electric door, the electric feed water pump recirculation regulating valve and the electric feed water pump recirculation regulating valve rear electric door and then returns to the deaerator, and the other route passes through the electric feed water pump outlet door and merges with the coaxial feed water pump outlet through the feed water main pipe and then goes to the heater.

3. The method according to claim 2, wherein The speed control system also includes a first solenoid valve connected to the disc brake, a second solenoid valve and a third solenoid valve connected to the hydraulic coupler, a fourth solenoid valve connected to the diaphragm coupling, a fifth solenoid valve connected to the hydraulic torque converter, and a sixth solenoid valve connected to the hydraulic brake.

4. The method according to claim 3, wherein The measurement data of the measuring points specifically include: pressure data of the pressure measuring point, speed data of the speed measuring point, and opening data of the valve measuring point.

5. The method according to claim 4, wherein Pressure measurement points include: coaxial water pump outlet water supply, electric water pump outlet water supply, water supply main pipe water supply, one or any combination; The speed measurement points include: one or any combination of coaxial water feed pump and electric water feed pump; The valve measurement points include: electric feed water pump inlet electric door, electric feed water pump outlet electric door, electric feed water pump recirculation regulating valve, electric feed water pump recirculation regulating valve front and rear electric doors, coaxial feed water pump recirculation regulating valve, hydraulic coupling scoop tube, hydraulic torque converter guide vane, the first solenoid valve, the third solenoid valve, the fourth solenoid valve, the sixth solenoid valve, or any combination thereof.

6. The method according to claim 5, wherein When the coaxial water feed pump fails or needs to be shut down for maintenance, the speed of the coaxial water feed pump is reduced by controlling the hydraulic torque converter, hydraulic brake, and hydraulic coupling in sequence according to the parameters, including: When the load of the steam turbine coaxially driven feedwater pump system is higher than a preset load, the guide vane opening of the torque converter is controlled to be closed to a first preset opening according to the parameters, the sixth solenoid valve is controlled to be opened, and the speed of the coaxial feedwater pump is controlled to be reduced by the hydraulic brake; When the speed of the coaxial water pump drops to the second preset speed, the fourth solenoid valve is controlled to close, the third solenoid valve is controlled to open, and the sixth solenoid valve is controlled to close in sequence according to the parameters; According to the parameters, the speed of the coaxial water feed pump is controlled to decrease by adjusting the opening of the scoop tube of the hydraulic coupling.

7. The method according to claim 6, wherein After the electric water pump paralleling program is completed, the speed of the coaxial water pump is reduced to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters, including: When the electric water pump parallel pump program is completed, the scoop tube opening of the hydraulic coupling is adjusted to the second preset opening according to the parameters, the third solenoid valve is controlled to close and the first solenoid valve is controlled to open in turn, and the speed of the coaxial water pump is controlled to be reduced to zero through the disc brake.

8. The method according to claim 7, wherein The control device includes: a first electro-hydraulic position control device and a second electro-hydraulic position control device; the control device calls the first electro-hydraulic position control device through a signal cable to control the guide vane opening of the hydraulic coupler; the control device calls the second electro-hydraulic position control device through a signal cable to control the guide vane opening of the torque converter.

9. The method according to claim 5, wherein The electric water pump paralleling procedure includes: When the electric water supply pump has finished filling water, the electric door of the electric water supply pump inlet is in the fully open state, and the electric door of the electric water supply pump outlet is in the fully closed state, the electric water supply pump recirculation regulating valve and the electric doors before and after the electric water supply pump recirculation regulating valve are controlled to fully open; Control the recirculation regulating valve of the coaxial water feed pump and the recirculation regulating valve of the electric water feed pump to the automatic position; the recirculation regulating valve of the coaxial water feed pump is placed in the automatic position, which means: its opening is adjusted according to the inlet water flow of the coaxial water feed pump; the recirculation regulating valve of the electric water feed pump is placed in the automatic position, which means: its opening is adjusted according to the inlet water flow of the electric water feed pump; Controlling the speed of the electric water supply pump to increase at a first preset rate until the difference between the water supply pressure at the outlet of the electric water supply pump and the water supply pressure at the outlet of the coaxial water supply pump is less than the first preset difference and the difference between the water supply pressure at the outlet of the electric water supply pump and the pressure of the water supply main pipe is less than the second preset difference; Controlling the electric door of the electric water supply pump outlet to open to full open at a second preset rate; Control the electric water supply pump to increase the speed to a fourth preset speed and the coaxial water supply pump to decrease the speed to a fifth preset speed; If the difference between the outlet water pressure of the electric water supply pump and the outlet water pressure of the coaxial water supply pump is greater than the third preset difference, and the difference between the main water supply pipe pressure and the outlet water pressure of the coaxial water supply pump is greater than the fourth preset difference, the outlet electric door of the coaxial water supply pump is controlled to close at the third preset rate; When the electric door at the outlet of the coaxial water supply pump is fully closed, the coaxial water supply pump is controlled to stop running.

10. A coaxial water pump stop control device, characterized in that: Used in control devices connected to the steam turbine coaxial drive feedwater pump system; The steam turbine coaxially driven feedwater pump system comprises: a steam turbine, a feedwater pump system, a speed regulating system connected to the steam turbine and the feedwater pump system respectively, and a boiler connected to the feedwater pump system; the steam turbine is used to drive the feedwater pump system; the speed regulating system is used to regulate the speed of the feedwater pump system; the feedwater pump system is used to supply water to the boiler; the feedwater pump system comprises a coaxial feedwater pump and an electric feedwater pump; the electric feedwater pump is connected to the coaxial feedwater pump; the speed regulating system comprises: a hydraulic torque converter, a disc brake, a hydraulic brake, and a hydraulic coupling; the shaft power of the steam turbine is transmitted through the input end of the speed regulating system and then divided into two shafts, one shaft is connected to the hydraulic torque converter and the hydraulic brake in sequence; the other shaft is connected to the hydraulic coupling and the disc brake in sequence; The device comprises: An acquisition module is used to acquire parameters of the steam turbine coaxially driven feedwater pump system in real time; the parameters include the load of the steam turbine coaxially driven feedwater pump system and measurement data of measurement points; The first control module is configured to control the torque converter, the hydraulic brake, and the hydraulic coupling in sequence to reduce the speed of the coaxial water feed pump when the coaxial water feed pump fails or needs to be shut down for maintenance according to the parameters; A pump paralleling module is configured to call and execute an electric feedwater pump paralleling program when the rotational speed of the coaxial feedwater pump decreases to less than a first preset rotational speed; the electric feedwater pump paralleling program is configured to control the electric feedwater pump to replace the coaxial feedwater pump to supply water to the boiler; The second control module is used to control the rotation speed of the coaxial water pump to zero by controlling the hydraulic coupling and the disc brake in sequence according to the parameters after the electric water pump parallel pump program is executed.

11. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 9 is implemented.

12. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 9 is implemented.

13. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 9 is implemented.

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