A control system and method suitable for high-lift water pump water pressure starting

Abstract

This invention provides a control system and method for starting a high-lift water pump by pressurization. The control system includes a gas generation and storage system and a working system. The gas generation and storage system includes an air compressor and a gas tank connected in series. The air compressor is used to fill the gas tank with pressurized gas, and the gas tank is connected to the working system to output pressurized gas to the working system. The working system includes a water pump and a compressed air pipeline and a drain pipeline connected to the water pump, respectively. The water pump is connected to the gas tank through the compressed air pipeline, and the compressed air pipeline is provided with an exhaust pipeline for discharging the gas pressurized into the water pump. The compressed air pipeline includes a third compressed air pipeline and a fourth compressed air pipeline, which are respectively connected to the front cover plate and the rear cover plate of the water pump. Using this control system and method can effectively overcome the problem that the water pump unit, due to the lack of movable guide vanes, has a much larger pressurized water volume than the pumped storage power station unit.

Description

Technical Field

[0001] This invention relates to the field of hydropower engineering technology, specifically to a control system and method suitable for the pressure start-up of high-lift water pumps. Background Technology

[0002] The starting of large high-lift water pump units includes pressure water start and live water start. In pressure water start, before the motor drives the impeller, compressed air is used to pressurize the water level in the impeller and volute to below the impeller, causing the water level in the cone tube to drop to a certain range. Then, the motor drives the impeller to quickly reach its rated speed, expelling air and causing the water level to rise. The impeller begins to work, and once certain conditions are met, the pump outlet ball valve is opened, pumping water to the outlet pool.

[0003] Currently, there are few examples of large-scale high-lift pumping stations starting up with pressurized water both domestically and internationally. Pumped storage power stations have mature experience in phase-adjustment pressurization. Their phase-adjustment pressurization system consists of a water turbine, a tailrace water level measurement system, a compressor exhaust valve system and its control system, a water ring formation and discharge system, and a volute pressure equalization system and its control system. Compared to pumped storage units, pump units do not have movable guide vanes. When the pump pressurizes water, it needs to simultaneously depressurize the volute, the pipeline from the volute to the ball valve, the impeller chamber, and the flow channel of the suction pipe outlet section. The volume of water to be pressurized is much larger than that of the pumped storage power station unit, posing a challenge to the selection of the gasification and storage system. Furthermore, since the top elevation of the volute and the flow channel of the suction pipe outlet section is higher than the top cover or the bottom elevation is lower than the lower plane of the seat ring, ensuring the depressurization or discharge of this portion of water and how to safely vent and fill the system become major engineering design challenges. Summary of the Invention

[0004] The purpose of this invention is to provide a control system and method for high-lift water pump unit pressurization start-up, which effectively overcomes the problem that the water volume of the water pump unit is much larger than that of the pumped storage power station unit when the water pump pressurizes water because the water pump unit does not have movable guide vanes.

[0005] This invention provides a control system suitable for the pressure water start-up of a high-lift water pump, including a gas generation and storage system and a working system;

[0006] The gas production and storage system includes an air compressor and a gas tank connected in series. The air compressor is used to fill the gas tank with pressurized gas, and the gas tank is connected to the working system to output pressurized gas to the working system.

[0007] The working system includes a water pump and a compressed air pipeline and a drain pipeline connected to the water pump respectively. The water pump is connected to a gas tank through the compressed air pipeline, and the compressed air pipeline is provided with an exhaust pipe for discharging the gas compressed into the water pump.

[0008] The compressed air pipeline includes a third compressed air pipeline and a fourth compressed air pipeline, which are respectively connected to the front cover plate and the rear cover plate of the water pump.

[0009] By pre-filling the air tank with a certain amount of pressurized gas using an air compressor, and then pressing the pressurized gas through the front and rear cover plates of the water pump, the water in the pump can be completely expelled from both directions. This ensures that the portion of water whose top elevation is higher than the top cover and the portion of water whose bottom elevation is lower than the lower plane of the seat ring are successfully expelled, thus guaranteeing the start-up of the pressurized water pump. This effectively overcomes the problem that the water pump unit, lacking movable guide vanes, results in a much larger water volume than the pumped storage power station unit during water pumping.

[0010] Furthermore, the compressed air pipeline includes a first compressed air pipeline and a second compressed air pipeline, and the exhaust pipeline includes a first exhaust pipeline and a second exhaust pipeline. The first compressed air pipeline and the second compressed air pipeline are connected in parallel. The first compressed air pipeline is connected to the third compressed air pipeline and the first exhaust pipeline through a tee connector. The second compressed air pipeline is connected to the fourth compressed air pipeline and the second exhaust pipeline through a tee connector. Both the first compressed air pipeline and the second compressed air pipeline are equipped with check valves to prevent water backflow.

[0011] The check valves installed on the first and second compressed air lines can prevent upstream water from flowing back into the gas production and storage system through the exhaust line, thus ensuring the safety of maintenance personnel. On the other hand, after the water is compressed and the water pump is idle, it can ensure that the water entering the water pump will not flow back into the gas production and storage system from the compressed air line.

[0012] Furthermore, one end of the exhaust pipe is connected to the compressed air pipe, and the other end extends to above the highest water level of the water pump's intake.

[0013] Extending the vent pipe to above the highest water level at the water pump's intake can prevent upstream water from entering through the vent pipe.

[0014] Furthermore, one end of the drainage pipe is connected to the water pump, and the other end is connected to the water pump's inlet pipe.

[0015] The water pump's inlet pipe is connected to the downstream position of the water intake, where the water pressure is lower. By using pressurized gas to direct the water in the pump to the inlet pipe, it is easier to pressurize the water and reduces the amount and pressure of pressurized gas required.

[0016] Furthermore, the air compressor is connected to the air tank via a series pipeline. The series pipeline is equipped with a second normally open valve, a third normally open valve, and a second check valve located between the second normally open valve and the third normally open valve. A branch pipeline is connected in parallel on the series pipeline, and a first normally closed valve is installed on the branch pipeline.

[0017] By setting up a second normally open valve and a third normally open valve, the maintenance of the second check valve can be facilitated. By setting up branch pipelines, it can be ensured that the air compressor can still replenish the air tank through the branch pipelines when the second check valve is under maintenance, thereby improving the reliability of the system.

[0018] Furthermore, the air compressor is a medium-pressure air compressor, and the volume of the air tank is set to be able to complete two water pressure start-up operations within 60 minutes, and to ensure that the pressure of the air tank remains between the lower limit of the normal working pressure and the minimum allowable pressure value after the two water pressure start-ups.

[0019] When selecting air tanks and air compressors, it is necessary to ensure that after one inflation, the air tank can complete two water pressure start-up operations within 60 minutes, and that the pressure of the air tank remains between the lower limit of the normal working pressure and the minimum allowable pressure value after the two water pressure start-ups, so as to ensure the safety of the air tank structure.

[0020] The present invention also provides a control method for starting a high-lift water pump by pressurizing water, comprising the following steps:

[0021] S1. Close the water pump outlet valve;

[0022] S2. Turn on the air compressor to fill the air tank until the air tank reaches the working pressure, then turn off the air compressor;

[0023] S3. Pressurized gas from the gas tank is introduced into the water pump through the front and rear cover plates of the water pump, and water in the volute, water from the volute to the water pump outlet valve, water in the impeller chamber and water in the suction pipe outlet section are discharged from the water pump through the drain pipe.

[0024] S4. Start the motor to drive the water pump to run at 100% rated speed and connect it to the grid for phase adjustment;

[0025] S5. Discharge the pressurized gas in the water pump through the vent pipe until the water pump is full of water, then close the vent pipe.

[0026] S6. Open the water pump outlet valve, and the water pump will start pumping water, completing the water pump pressure start-up.

[0027] Furthermore, in step S2, the gas that the air compressor fills into the gas tank is sufficient to enable the water pump to complete two water pumping starts within 60 minutes, and after the two water pumping starts are completed, the pressure in the gas tank will be maintained between the lower limit of the normal working pressure and the minimum allowable pressure value.

[0028] Furthermore, in step S3, the water level in the suction pipe is pressed down to a position 2m below the front cover plate of the water pump impeller.

[0029] A 2m safety margin is provided to prevent water level fluctuations from affecting the impeller.

[0030] Furthermore, step S5 includes closing the exhaust pipe after the water level in the pump has submerged the impeller and the water level in the exhaust pipe is equal to the upstream water level.

[0031] The water level in the exhaust pipe is the same as the upstream water level, which ensures that the impeller is completely submerged in water and all the gas has been discharged from the water pump.

[0032] The beneficial effects of this invention are as follows:

[0033] 1. This invention uses an air compressor to pre-charge a certain amount of pressurized gas into the air tank, and then pressurizes the gas through the front and rear cover plates of the water pump. This allows the water in the pump to be completely expelled from two directions, ensuring that the portion of water above the top of the volute and its outlet flow channel that is higher than the top cover is successfully expelled, and the portion of water below the bottom of the seat ring that is lower than the bottom plane is successfully expelled. This provides a guarantee for pressurized water startup and effectively overcomes the problem that the water volume of the pump unit is much larger than that of the pumped storage power station unit when the pump is pressurizing water because the pump unit does not have movable guide vanes.

[0034] 2. This invention achieves its goals through reasonable selection, specifically by using a medium-pressure air compressor with a rated working pressure of 8.0 MPa and a nominal pressure of 8.0 MPa for the air tank, with a volume of 10 m³. 3 This allows the air tank to complete two water pressure starts and recover to the pressure required for the next water pressure operation within 60 minutes. Furthermore, it ensures that the air tank pressure remains between the lower limit of the normal operating pressure and the minimum allowable pressure value after two water pressure starts without starting the medium-pressure air compressor.

[0035] 3. By extending the exhaust pipe to above the highest water level at the water pump's intake, this invention can prevent upstream water from flowing back into the gasification and storage system through the exhaust pipe. Furthermore, by installing check valves on the first and second compressed air pipes, it can ensure that water entering the water pump will not flow back into the gasification and storage system from the compressed air pipes after water pressure and pump idling are completed, thus protecting the lives of maintenance personnel.

[0036] 4. This invention, by setting a second normally open valve, a second check valve, and a third normally open valve, with the second check valve positioned between the second and third normally open valves, allows the second and third normally open valves to be closed for maintenance when the second check valve malfunctions. By setting up a branch pipeline, when the second check valve is being maintained, the first normally closed valve on the branch pipeline can be opened to ensure that the air compressor supplies air to the air tank, thus improving the reliability of the system.

[0037] 5. By connecting the drainage pipe to the water pump's inlet pipe, and with the water pump's inlet pipe located downstream of the water intake where the water pressure is low, the present invention uses pressurized gas to guide the water in the pump to the water pump's inlet pipe, which makes it easier to pressurize the water and reduces the amount and pressure of pressurized gas used.

[0038] 6. This invention ensures that the impeller is completely submerged in water and that all gas has been discharged from the water pump by observing the level gauge in the water pump and the water level in the exhaust pipe being level with the upstream water level. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the control system of the present invention;

[0040] Figure 2 This is a flowchart of the control method of the present invention;

[0041] Reference numerals: 1-Gas generation and storage system; 2-Working system; 3-Air compressor; 4-Gas tank; 5-Air compressor output pipeline; 6-First check valve; 7-First normally open valve; 8-Series pipeline; 9-Second normally open valve; 10-Third normally open valve; 11-Second check valve; 12-Branch pipeline; 13-First normally closed valve; 14-Sixth normally open valve; 15-Gas input pipeline; 16-Fourth normally open valve; 17-Gas output pipeline; 18-Fifth normally open valve; 19-Pressure sensor; 20-Pressure transmitter; 21-Drainage pipeline; 22-Second normally closed valve; 23-Water pump; 24-Main compressed air pipeline; 25-First compressed air pipeline Piping; 26-Second Compressed Air Pipeline; 27-Third Compressed Air Pipeline; 28-Fourth Compressed Air Pipeline; 29-First Exhaust Pipeline; 30-Second Exhaust Pipeline; 31-Drainage Pipeline; 32-Seventh Normally Open Valve; 33-Third Check Valve; 34-Eighth Normally Open Valve; 35-Fourth Check Valve; 36-Third Normally Closed Valve; 37-Fourth Normally Closed Valve; 38-Gas Diffusion Pressure Reducing Device; 39-Level Gauge; 40-Ninth Normally Open Valve; 41-Front Cover Plate; 42-Rear Cover Plate; 43-Impeller Chamber; 44-Seated Ring; 45-Top Cover; 46-Volume; 47-Pump Outlet Valve; 48-Water Lifting Pipe; 49-Suction Pipe; 50-Inlet Pipe; Detailed Implementation

[0042] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0043] like Figure 1 As shown, Figure 1 As shown, a control system suitable for the pressure water start-up of a high-lift water pump includes a gas generation and storage system 1 and a working system 2. The gas generation and storage system 1 supplies medium-pressure gas to the working system 2 by storing medium-pressure gas, thereby enabling the working system 2 to start up with pressure water.

[0044] The gas generation and storage system 1 includes air compressors 3 and gas tanks 4 connected in series. In this embodiment, five air compressors 3 and two gas tanks 4 are provided. The five air compressors 3 are connected in parallel, and the two gas tanks 4 are connected in parallel. Each air compressor output pipeline 5 is equipped with a first check valve 6 and a first normally open valve 7. The check valve can prevent gas in the gas tank 4 from overflowing from the air compressor output pipeline 5 after the air compressor 3 is turned off. The air compressors 3 are connected to the gas tanks 4 through a series pipeline 8. The series pipeline 8 is equipped with a second normally open valve 9, a third normally open valve 10, and a second check valve 11. The second check valve 11 is located between the second normally open valve 9 and the third normally open valve 10. A branch pipeline 12 is connected in parallel to the series pipeline 8, and a first normally closed valve 13 is provided on the branch pipeline 12. One of the five air compressors 3 is set as a spare, and the other four are in normal use.

[0045] Under normal operating conditions, air compressor 3 fills gas tank 4 with gas through first check valve 6, first normally open valve 7, second normally open valve 9, second check valve 11, and third normally open valve 10. When second check valve 11 malfunctions, second normally open valve 9 and third normally open valve 10 are closed, and second check valve 11 is inspected. When second check valve 11 is inspected, in order to ensure that air compressor 3 can still replenish gas to gas tank 4, first normally closed valve 13 can be opened to ensure that the system does not stop working due to the inspection of second check valve 11, thereby improving the reliability of the system.

[0046] Multiple parallel gas tanks 4 are connected in series via a sixth normally open valve 14 to ensure that the gas pressure in each gas tank 4 is the same, thus guaranteeing the safety of the gas tank 4. Each gas tank 4 is connected to the series pipeline via a gas input pipeline 15, and each gas input pipeline 15 is equipped with a fourth normally open valve 16. Each gas tank 4 is connected to the working system 2 via a gas output pipeline 17, and the gas output pipeline 17 is equipped with a fifth normally open valve 18, a pressure sensor 19, and a pressure transmitter 20. The fifth normally open valve 18 is located between the gas tank 4 and the pressure sensor 19. In this embodiment, two gas tanks 4 are provided, and the two gas tanks 4 are connected by a sixth normally open valve 14. The gas pressure in the different gas tanks 4 is the same, and the gas pressure is balanced among the gas tanks 4, making the gas compression process smoother. Five pressure sensors 19 are provided, and one pressure transmitter 20 is provided. The pressure transmitter 20 is used to convert the pressure signal into an electrical signal and feed it back to the central control room for equipment control. The pressure sensors 19 are only used to monitor and transmit pressure signals. Multiple pressure sensors 19 correspond to different pressure values, and then the control signal is transmitted through the pressure transmitter 20.

[0047] The gas tank 4 is also connected to a sewage pipe 21, and a second normally closed valve 22 is installed on the sewage pipe 21.

[0048] Because the water pump unit 23 consumes a large amount of gas for pressurizing water, the gas production and storage system 1 adopts a medium-pressure system. The nominal pressure of the medium-pressure system is 2.5MPa, 4.0MPa, 6.3MPa, 8.0MPa, and 10MPa. The specific nominal pressure is selected according to the gas consumption. In this embodiment, the air compressor 3 is a medium-pressure air compressor with a rated working pressure of 8.0MPa. The nominal pressure of the gas tank 4 is 8.0MPa, and the volume is 10m³. 3 .

[0049] Through the above selection, the pressurized air tank can perform two pressurized water pump 23 starts within 60 minutes, ensuring that the pressurized air tank returns to the pressure required for the next pressurized water operation within 60 minutes. Furthermore, after completing two pressurized water starts without starting the medium-pressure air compressor, the pressure in the air tank remains between the lower limit of the normal operating pressure and the minimum allowable pressure value. The lower limit of the normal operating pressure refers to the lower limit of the working pressure at which the air tank 4 can achieve two pressurization operations. If it is lower than this value, the air tank 4 will not be able to achieve two pressurization operations, but this will not affect the structural safety of the air tank 4. The minimum allowable pressure value refers to the lowest pressure value allowed by the air tank 4 itself; if it is lower than this value, it will affect the structural safety of the air tank 4. The minimum allowable pressure value is significantly lower than the lower limit of the normal operating pressure.

[0050] The working system 2 includes a water pump 23, a compressed air pipeline, a first exhaust pipeline 29, a second exhaust pipeline 30, and a drainage pipeline 31.

[0051] The compressed air pipeline includes a main compressed air pipeline 24, a first compressed air pipeline 25, a second compressed air pipeline 26, a third compressed air pipeline 27, and a fourth compressed air pipeline 28. One end of the main compressed air pipeline 24 is connected to the gas output pipeline 17, and the other end is connected to the first compressed air pipeline 25 and the second compressed air pipeline 26 via a tee connector. The first compressed air pipeline 25 and the second compressed air pipeline 26 are connected in parallel. The first compressed air pipeline 25 is connected to the third compressed air pipeline 27 and the first exhaust pipeline 29 via a tee connector. The third compressed air line 27 extends into the water pump 23 to the front cover plate 41 of the impeller. The second compressed air line 26 is connected to the fourth compressed air line 28 and the second exhaust line 30 through a tee connector. The fourth compressed air line 28 extends into the water pump 23 to the rear cover plate 42 of the impeller. The third compressed air line 27 and the fourth compressed air line 28 are used to fill the water pump 23 with medium-pressure gas from the gas tank 4 for water pumping. The first exhaust line 29 and the second exhaust line 30 are used to discharge the gas filled into the water pump 23.

[0052] By pressing medium-pressure gas into the water pump 23 through the front cover plate 41 and the rear cover plate 42 of the impeller, the water in the volute 46, the water from the volute 46 to the water pump outlet valve 47, the water in the impeller chamber 43 and the water outlet section of the suction pipe 49 can be completely expelled from the water pump 23 through the drainage pipe 31. It can also ensure that the water in the volute 46 and its outlet flow channel that is higher than the top cover 45 and lower than the seat ring 44 is completely expelled from the water pump 23, preventing the water from affecting the water pump 23 when it is running dry.

[0053] The first compressed air pipeline 25 is equipped with a seventh normally open valve 32 and a third check valve 33. The second compressed air pipeline 26 is equipped with an eighth normally open valve 34 and a fourth check valve 35. The third check valve 33 and the fourth check valve 35 can prevent water in the water pump 23 from flowing back to the gas production and storage system 1 through the first compressed air pipeline 25 and the second compressed air pipeline 26. The first exhaust pipeline 29 is equipped with a third normally closed valve 36. The second exhaust pipeline 30 is equipped with a fourth normally closed valve 37. Both the first exhaust pipeline 29 and the second exhaust pipeline 30 are equipped with a gas diffusion pressure reducing device 38. The gas diffusion pressure reducing device 38 can effectively reduce the pressure of the discharged medium-pressure gas and effectively protect the life safety of maintenance personnel.

[0054] One end of the drainage pipe 31 is located at the rear cover plate 42 of the impeller, and the other end is connected to the inlet pipe 50 of the water pump 23. A ninth normally open valve 40 is provided on the drainage pipe 31. The drainage pipe 31 is used to draw water out of the water pump 23.

[0055] The water pump 23 is connected to a level gauge 39, which is used to measure the water level in the water pump 23 to determine whether the water level has submerged the impeller and reached the working conditions.

[0056] Method of using this invention:

[0057] S1. In the initial state, all valves are closed. The water pump outlet valve 47 is closed, and the water pump 23 and the water pump pipe 48 of the water pump 23 are filled with water.

[0058] S2. Turn on four air compressors 3, with one air compressor 3 as a standby. Open the first normally open valve 7 on the air compressor output pipeline 5 of the four air compressors 3. The first normally open valve 7 of the standby air compressor 3 is closed. Open the second normally open valve 9, the third normally open valve 10, the fourth normally open valve 16, and the sixth normally open valve 14. The four air compressors 3 fill the two air tanks 4 with gas. When the medium-pressure gas in the air tanks 4 reaches the working pressure, turn off all air compressors 3 and close the first normally open valve 7, the second normally open valve 9, the third normally open valve 10, and the fourth normally open valve 16. At this time, the medium-pressure gas in the two air tanks 4 can complete the water pump 23 pressure start twice within 60 minutes, in accordance with the water pump 23 pressure start specification standard.

[0059] S3. Open the fifth normally open valve 18 on the two gas output pipelines 17, and open the seventh normally open valve 32, the eighth normally open valve 34, and the ninth normally open valve 40. Fill the medium-pressure gas in the gas tank 4 into the water pump 23 impeller rear cover plate 42 and front cover plate 41. Pump out the water in the volute 46, the water from the volute 46 to the water pump outlet valve 47, the water in the impeller chamber 43 and the water outlet section of the suction pipe 49 through the drain pipe 31. Pump out the water level in the suction pipe 49 to a position 2m below the water pump 23 impeller front cover plate 41.

[0060] The medium-pressure gas in the gas tank 4 is simultaneously injected into the impeller rear cover plate 42 and front cover plate 41 of the water pump 23 to ensure that the water body at the top of the volute 46 and its outlet flow channel, which is higher than the top cover 45, is successfully pressed down, and the water body at the bottom, which is lower than the lower plane of the seat ring 44, is successfully pressed down.

[0061] During the inflation process, the pressure of the gas tank 4 will gradually decrease. After two inflation cycles, the pressure will remain between the lower limit of the normal working pressure and the minimum allowable pressure value, without affecting the structural safety of the gas tank 4.

[0062] It should be noted that, in order to reduce the water resistance torque when the water pump 23 starts under no-load conditions, the water in the flow channel of the water pump 23 needs to be forced out of the impeller chamber 43 of the water pump 23, and the lowest point of the impeller chamber 43 is the front cover plate 41 of the impeller. In order to reserve a certain safety margin and prevent water level fluctuations from affecting the impeller, the water level in the flow channel of the water pump 23 needs to be pressed to a position 2m below the front cover plate 41.

[0063] S4. Start the motor to drive the water pump 23 to idle speed to 100% of its rated speed, then connect to the grid and adjust the phase, maintaining the water pump 23 at 100% of its rated speed. The 100% rated speed of the water pump 23 corresponds to a grid frequency of 50Hz.

[0064] S5. After grid connection is completed, exhaust and water filling begin. Close the fifth normally open valve 18, the seventh normally open valve 32, the eighth normally open valve 34, and the ninth normally open valve 40. Open the third normally closed valve 36 and the fourth normally closed valve 37. Medium-pressure gas is discharged, and water gradually enters the water pump 23. The water in the impeller chamber 43 rises slowly under the action of the upstream water level. The medium-pressure gas in the impeller chamber 43 is depressurized by the gas diffusion and pressure reducing device 38 on the first exhaust pipe 29 and the second exhaust pipe 30 and then discharged from a position higher than the highest water level at the water intake. This prevents the water at the water intake from flowing back into the working system 2 through the first exhaust pipe 29 and the second exhaust pipe 30. Continue until the level gauge 39 shows that the water level has risen and submerged the impeller, and the water in the impeller chamber 43 enters the exhaust pipe and is level with the upstream water level. Then close the third normally closed valve 36 and the fourth normally closed valve 37 to ensure that the impeller is submerged in water and all medium-pressure gas has been discharged.

[0065] S6. Open the water pump outlet valve 47, and the water pump 23 will start pumping water.

[0066] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A control system suitable for pressure water start-up of high-lift water pumps, characterized in that: It includes a gas production and storage system (1) and a working system (2); The gas production and storage system (1) includes an air compressor (3) and a gas tank (4) connected in series. The air compressor (3) is used to fill the gas tank (4) with pressurized gas. The gas tank (4) is connected to the working system (2) to output pressurized gas to the working system (2). The working system (2) includes a water pump (23) and a compressed air pipeline and a drain pipeline (31) respectively connected to the water pump (23). The water pump (23) is connected to the gas tank (4) through the compressed air pipeline. The compressed air pipeline is provided with an exhaust pipeline for discharging the gas compressed into the water pump (23). The compressed air pipeline includes a third compressed air pipeline (27) and a fourth compressed air pipeline (28), which are respectively connected to the front cover plate (41) and the rear cover plate (42) of the water pump (23); The compressed air pipeline includes a first compressed air pipeline (25) and a second compressed air pipeline (26), and the exhaust pipeline includes a first exhaust pipeline (29) and a second exhaust pipeline (30). The first compressed air pipeline (25) and the second compressed air pipeline (26) are connected in parallel. The first compressed air pipeline (25) is connected to the third compressed air pipeline (27) and the first exhaust pipeline (29) through a three-way connector. The second compressed air pipeline (26) is connected to the fourth compressed air pipeline (28) and the second exhaust pipeline (30) through a three-way connector. Both the first compressed air pipeline (25) and the second compressed air pipeline (26) are equipped with check valves to prevent water backflow. One end of the exhaust pipe is connected to the compressed air pipe, and the other end extends to above the highest water level of the water intake of the water pump (23). One end of the drainage pipe (31) is located at the rear cover plate (42) of the impeller, and the other end is connected to the inlet pipe (50) of the water pump (23).

2. The control system for high-lift water pump pressure start-up as described in claim 1, characterized in that: The air compressor (3) is connected to the air tank (4) through a series pipeline (8). The series pipeline (8) is equipped with a second normally open valve (9), a third normally open valve (10), and a second check valve (11) located between the second normally open valve (9) and the third normally open valve (10). A branch pipeline (12) is connected in parallel on the series pipeline (8), and a first normally closed valve (13) is installed on the branch pipeline (12).

3. The control system for high-lift water pump pressure start-up as described in claim 1, characterized in that: The air compressor (3) is a medium-pressure air compressor, and the volume of the air tank (4) is set to be able to complete two water pressure start-up operations within 60 minutes, and to ensure that the pressure of the air tank (4) after the two water pressure start-ups is maintained between the lower limit of the normal working pressure and the minimum allowable pressure value.

4. A control method for a control system applicable to the pressure water start-up of a high-lift water pump as described in any one of claims 1 to 3, characterized in that: Includes the following steps: S1. Close the water pump outlet valve (47); S2. Turn on the air compressor (3) to fill the air tank (4) with air until the air tank (4) reaches the working pressure, and then turn off the air compressor (3). S3. Pressurized gas from the gas tank (4) is introduced into the water pump (23) through the front cover plate (41) and rear cover plate (42) of the water pump (23), and water in the volute (46), water from the volute (46) to the water pump outlet valve (47), water in the impeller chamber (43) and water in the outlet section of the suction pipe (49) are discharged from the water pump (23) through the drain pipe (31). S4. Start the motor to drive the water pump (23) to run at 100% rated speed and connect to the grid for phase adjustment; S5. Discharge the pressurized gas in the water pump (23) through the exhaust pipe until the water pump (23) is full of water, and then close the exhaust pipe. S6. Open the water pump outlet valve (47), and the water pump (23) will pump water to complete the water pump (23) pressure start-up.

5. The control method as described in claim 4, characterized in that: In step S2, the gas that the air compressor (3) fills into the air tank (4) is enough to enable the water pump (23) to complete two water pressure starts within 60 minutes, and after the two water pressure starts are completed, the pressure in the air tank (4) will be maintained between the lower limit of the normal working pressure and the minimum allowable pressure value.

6. The control method as described in claim 5, characterized in that: In step S3, the water level in the suction pipe (49) is pressed down to a position 2m below the front cover plate (41) of the impeller of the water pump (23).

7. The control method as described in claim 5, characterized in that: Step S5 includes closing the exhaust pipe after the water level in the water pump (23) has submerged the impeller and the water level in the exhaust pipe is equal to the upstream water level.

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