A generator stator bar de-clogging system and control method

Abstract

The application discloses a generator stator bar dredging system and a control method, and the system comprises a water inlet pressure switch, an air inlet pressure switch, a water inlet electromagnetic valve, an air inlet electromagnetic valve, a first pressure relief electromagnetic valve, a second pressure relief electromagnetic valve, a high-pressure water pump, an internal cooling water tank and an air storage device. When the water pressure at the first end of the hollow conduit to be dredged reaches a preset maximum pressure, the water inlet pressure switch is disconnected and triggers the closing of the water inlet electromagnetic valve and the second pressure relief electromagnetic valve. When the water pressure is not higher than a preset minimum pressure, the water inlet pressure switch is closed and triggers the opening of the water inlet electromagnetic valve and the second pressure relief electromagnetic valve. When the air pressure at the second end of the hollow conduit to be dredged reaches a preset maximum pressure, the air inlet pressure switch is disconnected and triggers the closing of the air inlet electromagnetic valve and the first pressure relief electromagnetic valve. When the air pressure is not higher than a preset minimum pressure, the air inlet pressure switch is closed and triggers the opening of the air inlet electromagnetic valve and the first pressure relief electromagnetic valve. The blocked stator bar can be dredged more efficiently without damaging the pipe wall of the stator bar.

Description

Technical Field

[0001] This application relates to the field of large generator technology, and more specifically, to a generator stator bar unblocking system and control method. Background Technology

[0002] Large generator stator coils with hollow copper conductors mostly use demineralized water as the cooling medium. The deposition of impurities, oxides, or corrosion products in the operating cooling water can easily cause blockage of the cooling water circuit inside the stator, resulting in a decrease in the cooling water flow rate inside the stator, an increase in the outlet water temperature, and local overheating of the generator stator bars. This can lead to aging of the generator insulation windings, reduced load operation, or even burnout of the coils, forcing a shutdown.

[0003] The blockage of generator stator bars is mainly caused by corrosion of copper conductors due to substandard cooling water quality. Due to the influence of extreme heat load design, the dimensions of the rectangular hollow conductors in the stator winding are generally 3-10mm in length, 1-3mm in width, and about 5000-12000mm in depth. These small-section hollow conductors are prone to blockage at bends and inlet / outlet joints. The deposits causing the blockage are mainly elemental copper, copper oxide, and iron oxide, as well as impurities such as coating fragments, resin fragments, sealing insulation material fragments, and solder.

[0004] In existing technologies, the following methods are generally used when blockage occurs in the stator bars of a generator:

[0005] (1) Perform high-pressure cleaning. Although this method has some effect, it cannot clear blockages inside the hollow conduit or at the corners of the hollow conduit. In fact, the more pressure is applied, the more severe the blockage becomes.

[0006] (2) Mechanical cleaning mainly uses tools such as copper brushes, vacuum cleaners, thin steel wires, and tweezers to clean the pipe openings. Mechanical cleaning can be used when there are foreign objects in the cap of a blocked hollow conduit, but it can only remove the foreign object fragments inside the cap. It often cannot clear blockages at a certain depth inside the pipe.

[0007] (3) Chemical cleaning: The choice of cleaning agent is generally based on the properties of copper and copper oxides. Commonly used agents include strong acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, as well as weak acids such as citric acid, glycolic acid, and aminosulfonic acid. Complexing agents such as ethylenediaminetetraacetic acid (EDTA) and ammonium persulfate (NH4)2S2O8 can also be selected. This method is effective against blockages caused by substances such as CuO and Cu2O. However, it is ineffective against powdery blockages caused by resins, rubber gaskets, and polyethylene gaskets. Furthermore, this method is highly sensitive to the dosage and duration of cleaning; improper handling can cause strong corrosion to the copper pipe walls, and the copper ions generated inside the pipe are difficult to remove completely, threatening the safe operation of the unit.

[0008] Therefore, how to more efficiently unclog blocked stator bars without damaging the stator bar tube wall is a technical problem that needs to be solved. Summary of the Invention

[0009] This invention discloses a generator stator bar unblocking system to solve the technical problems of low efficiency and poor effect in existing stator bar unblocking technology. The system includes a water inlet pressure switch, an air inlet pressure switch, a water inlet solenoid valve, an air inlet solenoid valve, a first pressure relief solenoid valve, a second pressure relief solenoid valve, a high-pressure water pump, an internal cooling water tank, and an air storage device.

[0010] One end of the water inlet pressure switch is connected to the first end of the hollow conduit to be cleared of the target stator bar. The two ends of the water inlet solenoid valve are respectively connected to the other end of the water inlet pressure switch and the outlet of the high-pressure water pump. The inlet of the high-pressure water pump is connected to the internal cooling water tank. One end of the air inlet pressure switch is connected to the second end of the hollow conduit to be cleared. The two ends of the air inlet solenoid valve are respectively connected to the other end of the air inlet pressure switch and the air supply end of the air storage device. The first pressure relief solenoid valve is used to discharge pressure medium from the first end of the hollow conduit to be cleared, and the second pressure relief solenoid valve is used to discharge pressure medium from the second end of the hollow conduit to be cleared.

[0011] Specifically, the water inlet pressure switch disconnects and triggers the closure of the water inlet solenoid valve and the second pressure relief solenoid valve when the water pressure at the first end of the hollow conduit to be unclogged reaches a preset maximum pressure; the water inlet pressure switch closes and triggers the opening of the water inlet solenoid valve and the second pressure relief solenoid valve when the water pressure is not higher than a preset minimum pressure; the air inlet pressure switch disconnects and triggers the closure of the air inlet solenoid valve and the first pressure relief solenoid valve when the air pressure at the second end of the hollow conduit to be unclogged reaches the preset maximum pressure; the air inlet pressure switch closes and triggers the opening of the air inlet solenoid valve and the first pressure relief solenoid valve when the air pressure is not higher than the preset minimum pressure.

[0012] Accordingly, the present invention also proposes a generator stator bar unblocking control method, applied to the system described above, the method comprising:

[0013] The internal cooling water in the internal cooling water tank is heated to a preset temperature;

[0014] Close and keep the water inlet solenoid valve, the air inlet solenoid valve, the first pressure relief solenoid valve and the second pressure relief solenoid valve de-energized;

[0015] Set the pressure at the gas supply end of the gas storage device to the preset maximum pressure;

[0016] Start the high-pressure water pump and set the outlet pressure of the high-pressure water pump to the preset maximum pressure;

[0017] Manually open the water inlet solenoid valve or the air inlet solenoid valve, and simultaneously energize the water inlet solenoid valve, the air inlet solenoid valve, the first pressure relief solenoid valve and the second pressure relief solenoid valve to make the system enter the oscillation and pressure unblocking mode. The oscillation and pressure unblocking mode includes alternating first set of triggering operations and second set of triggering operations.

[0018] When the system exits the oscillation and pressure unblocking mode and water-side pressurization or air-side pressurization cannot be stopped, it is determined that the hollow conduit to be unblocked has been unblocked.

[0019] The first set of triggering operations includes: when the water pressure reaches the preset maximum pressure, the inlet pressure switch outputs a disconnect signal and triggers the closure of the inlet solenoid valve and the second pressure relief solenoid valve to stop water-side pressurization; if the air pressure is not higher than the preset minimum pressure at this time, the inlet pressure switch outputs a closing signal and triggers the opening of the inlet solenoid valve and the first pressure relief solenoid valve to start air-side pressurization. The second set of triggering operations includes: when the air pressure reaches the preset maximum pressure, the inlet pressure switch outputs a disconnect signal and triggers the closure of the inlet solenoid valve and the first pressure relief solenoid valve to stop air-side pressurization; if the water pressure is not higher than the preset minimum pressure at this time, the inlet pressure switch outputs a closing signal and triggers the opening of the inlet solenoid valve and the second pressure relief solenoid valve to start water-side pressurization.

[0020] By applying the above technical solutions, the generator stator bar unblocking system includes a water inlet pressure switch, an air inlet pressure switch, a water inlet solenoid valve, an air inlet solenoid valve, a first pressure relief solenoid valve, a second pressure relief solenoid valve, a high-pressure water pump, an internal cooling water tank, and an air storage device. The water inlet pressure switch disconnects and triggers the closure of the water inlet solenoid valve and the second pressure relief solenoid valve when the water pressure at the first end of the hollow conduit to be unblocked reaches the preset maximum pressure. The water inlet pressure switch closes and triggers the opening of the water inlet solenoid valve and the second pressure relief solenoid valve when the water pressure is not higher than the preset minimum pressure. The air inlet pressure switch disconnects and triggers the closure of the air inlet solenoid valve and the first pressure relief solenoid valve when the air pressure at the second end of the hollow conduit to be unblocked reaches the preset maximum pressure. The air inlet pressure switch closes and triggers the opening of the air inlet solenoid valve and the first pressure relief solenoid valve when the air pressure is not higher than the preset minimum pressure. This allows for more efficient unblocking of clogged stator bars without damaging the stator bar tube wall. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a generator stator bar unblocking system according to an embodiment of the present invention is shown;

[0023] Figure 2 A schematic diagram of the circuit structure of the generator stator bar unblocking system in an embodiment of the present invention is shown;

[0024] Figure 3 A schematic flowchart of a generator stator bar unblocking control method according to an embodiment of the present invention is shown;

[0025] Figure 4 A schematic diagram illustrating the principle of the oscillation compression unblocking mode in an embodiment of the present invention is shown.

[0026] in, Figure 1 and Figure 2 In the middle, 10. Target stator bar; 11. Hollow conduit to be cleared; 21. Inlet pressure switch; 22. Inlet solenoid valve; 23. High-pressure water pump; 24. Internal cooling water tank; 25. First pressure relief solenoid valve; 26. Heating device; 31. Inlet pressure switch; 32. Inlet solenoid valve; 33. Gas storage device; 34. Second pressure relief solenoid valve. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] This application provides a generator stator bar unblocking system, such as... Figure 1 As shown, it includes an inlet water pressure switch 21, an inlet air pressure switch 31, an inlet water solenoid valve 22, an inlet air solenoid valve 32, a first pressure relief solenoid valve 25, a second pressure relief solenoid valve 34, a high-pressure water pump 23, an internal cooling water tank 24, and an air storage device 33, wherein,

[0029] One end of the inlet pressure switch 21 is connected to the first end of the hollow conduit 11 to be unclogged. The two ends of the inlet solenoid valve 22 are respectively connected to the other end of the inlet pressure switch 21 and the outlet of the high-pressure water pump 23. The inlet of the high-pressure water pump 23 is connected to the internal cooling water tank 24. One end of the air pressure switch 31 is connected to the second end of the hollow conduit 11 to be unclogged. The two ends of the air solenoid valve 32 are respectively connected to the other end of the air pressure switch 31 and the air supply end of the air storage device 33. The first pressure relief solenoid valve 25 is used to discharge the pressure medium from the first end of the hollow conduit 11 to be unclogged. The second pressure relief solenoid valve 34 is used to discharge the pressure medium from the second end of the hollow conduit 11 to be unclogged.

[0030] Specifically, the water inlet pressure switch 21 disconnects and triggers the closure of the water inlet solenoid valve 22 and the second pressure relief solenoid valve 34 when the water pressure at the first end of the hollow conduit 11 to be cleared reaches the preset maximum pressure; the water inlet pressure switch 21 closes and triggers the opening of the water inlet solenoid valve 22 and the second pressure relief solenoid valve 34 when the water pressure is not higher than the preset minimum pressure; the air inlet pressure switch 31 disconnects and triggers the closure of the air inlet solenoid valve 32 and the first pressure relief solenoid valve 25 when the air pressure at the second end of the hollow conduit 11 to be cleared reaches the preset maximum pressure; the air inlet pressure switch 31 closes and triggers the opening of the air inlet solenoid valve 32 and the first pressure relief solenoid valve 25 when the air pressure is not higher than the preset minimum pressure.

[0031] In this embodiment, the generator is equipped with multiple stator bars, each stator bar including multiple hollow conduits. The hollow conduit 11 to be cleared is located in the target stator bar 10. There is a foreign object blocking the middle of the hollow conduit 11 to be cleared. Water can be used to pressurize the first end of the hollow conduit 11 to be cleared, and gas can be used to pressurize the second end of the hollow conduit 11 to be cleared. Pressurizing with water requires opening the water inlet solenoid valve 22 and the second pressure relief solenoid valve 34. When the second pressure relief solenoid valve 34 is open, the pressure medium is discharged from the second end of the hollow conduit 11 to be cleared. Pressurizing with gas requires opening the air inlet solenoid valve 32 and the first pressure relief solenoid valve 25. When the first pressure relief solenoid valve 25 is open, the pressure medium is discharged from the first end of the hollow conduit 11 to be cleared.

[0032] Both the water inlet pressure switch 21 and the air inlet pressure switch 31 can display the pressure or upload the pressure detection value to the operator's terminal for convenient pressure monitoring. The water inlet solenoid valve 22, the air inlet solenoid valve 32, the first pressure relief solenoid valve 25, and the second pressure relief solenoid valve 34 are all normally closed solenoid valves.

[0033] To ensure system reliability, in some embodiments of this application, such as... Figure 1 As shown, one end of the first pressure relief solenoid valve 25 is connected to the pipeline between the water inlet pressure switch 21 and the water inlet solenoid valve 22, and the other end is emptied. One end of the second pressure relief solenoid valve 34 is connected to the pipeline between the air inlet pressure switch 31 and the air inlet solenoid valve 32, and the other end is emptied.

[0034] Optionally, as another implementation, one end of the first pressure relief solenoid valve 25 is connected to the pipe between one end of the inlet pressure switch 21 and the first end of the hollow conduit 11 to be unclogged, and the other end is emptied; one end of the second pressure relief solenoid valve 34 is connected to the pipe between one end of the inlet pressure switch 31 and the second end of the hollow conduit 11 to be unclogged, and the other end is emptied.

[0035] To improve system reliability, in some embodiments of this application, such as Figure 2 As shown, the system also includes:

[0036] The power switch QS is used to supply or de-energize the water inlet pressure switch 21, the air inlet pressure switch 31, the water inlet solenoid valve 22, the air inlet solenoid valve 32, the first pressure relief solenoid valve 25, and the second pressure relief solenoid valve 34.

[0037] The first contactor KM1 is used to enable the inlet pressure switch 21 to be linked with the inlet solenoid valve 22 and the second pressure relief solenoid valve 34.

[0038] The second contactor KM2 is used to enable the intake pressure switch 31 to be linked with the intake solenoid valve 32 and the first pressure relief solenoid valve 25.

[0039] To improve system reliability, in some embodiments of this application, such as Figure 2 As shown, the live wire and neutral wire on one side of the power switch QS are connected to the power supply. The water inlet pressure switch 21, the coil of the first contactor KM1, and the normally closed contact of the second contactor KM2 are connected in series between the live wire and neutral wire on the other side of the power switch QS. The air inlet pressure switch 31, the coil of the second contactor KM2, and the normally closed contact of the first contactor KM1 are connected in series between the live wire and neutral wire on the other side of the power switch QS. The air inlet solenoid valve 32 and the first pressure relief solenoid valve 25 are connected to the live wire and neutral wire on the other side of the power switch QS via the main contact of the second contactor KM2. The water inlet solenoid valve 22 and the second pressure relief solenoid valve 34 are connected to the live wire and neutral wire on the other side of the power switch QS via the main contact of the first contactor KM1.

[0040] In this embodiment, the inlet pressure switch 21 is disconnected when the water pressure at the first end of the hollow conduit 11 to be cleared reaches the preset maximum pressure. The coil of the first contactor KM1 is de-energized, the main contact of the first contactor KM1 is disconnected, the inlet solenoid valve 22 and the second pressure relief solenoid valve 34 are de-energized and closed, and at the same time the normally closed contact of the first contactor KM1 is closed.

[0041] When the water pressure switch 21 closes, the coil of the first contactor KM1 is energized, the main contact of the first contactor KM1 closes, the water inlet solenoid valve 22 and the second pressure relief solenoid valve 34 are energized and opened, and at the same time, the normally closed contact of the first contactor KM1 is opened.

[0042] When the air pressure at the second end of the hollow conduit 11 to be cleared reaches the preset maximum pressure, the coil of the second contactor KM2 is de-energized, the main contact of the second contactor KM2 is opened, the air intake solenoid valve 32 and the first pressure relief solenoid valve 25 are de-energized and closed, and at the same time, the normally closed contact of the second contactor KM2 is closed.

[0043] When the air pressure switch 31 closes, the coil of the second contactor KM2 is energized, the main contact of the second contactor KM2 closes, the air intake solenoid valve 32 and the first pressure relief solenoid valve 25 are energized and opened, and at the same time, the normally closed contact of the second contactor KM2 opens.

[0044] Optional, the power supply is 220V.

[0045] To further improve system reliability, in some embodiments of this application, a filter screen is installed before the inlet of the high-pressure water pump 23, the gas storage device 33 contains nitrogen, and a pressure reducing valve is installed at the gas supply end of the gas storage device 33, such as... Figure 1 As shown, a heating device 26 is installed in the internal cooling water tank 24.

[0046] In this embodiment, a filter screen is installed before the inlet of the high-pressure water pump 23 to prevent impurities from entering the hollow conduit 11 to be unclogged. The gas storage device 33 may include multiple nitrogen cylinders, and a pressure reducing valve is provided at the gas supply end of the gas storage device 33 to ensure that the nitrogen pressure is controllable. The demineralized water in the internal cooling water tank 24 can be heated to a preset temperature by the heating device 26 to improve the unclogging effect.

[0047] Optional, the preset temperature is 80~100℃.

[0048] To ensure the reliability of the stator bars, in some embodiments of this application, the target stator bar 10 is one stator bar of the generator or all stator bars of the generator. The preset maximum pressure is a first preset pressure when the target stator bar 10 is one stator bar of the generator, and a second preset pressure when the target stator bar 10 is all stator bars of the generator. The first preset pressure is higher than the second preset pressure.

[0049] Optionally, the preset maximum pressure is lower than the design bearing pressure of the stator bar, with the first preset pressure not exceeding 1.8 MPa and the second preset pressure not exceeding 1.2 MPa.

[0050] Optionally, the preset minimum pressure is no higher than 0.1 MPa.

[0051] By applying the above technical solutions, the generator stator bar unblocking system includes a water inlet pressure switch, an air inlet pressure switch, a water inlet solenoid valve, an air inlet solenoid valve, a first pressure relief solenoid valve, a second pressure relief solenoid valve, a high-pressure water pump, an internal cooling water tank, and an air storage device. The water inlet pressure switch disconnects and triggers the closure of the water inlet solenoid valve and the second pressure relief solenoid valve when the water pressure at the first end of the hollow conduit to be unblocked reaches the preset maximum pressure. The water inlet pressure switch closes and triggers the opening of the water inlet solenoid valve and the second pressure relief solenoid valve when the water pressure is not higher than the preset minimum pressure. The air inlet pressure switch disconnects and triggers the closure of the air inlet solenoid valve and the first pressure relief solenoid valve when the air pressure at the second end of the hollow conduit to be unblocked reaches the preset maximum pressure. The air inlet pressure switch closes and triggers the opening of the air inlet solenoid valve and the first pressure relief solenoid valve when the air pressure is not higher than the preset minimum pressure. This system can more efficiently unblock clogged stator bars without damaging the stator bar tube wall.

[0052] Accordingly, this invention also proposes a generator stator bar unblocking control method, applied to the system described above, such as... Figure 3 As shown, the method includes the following steps:

[0053] Step S101: Heat the internal cooling water in the internal cooling water tank to a preset temperature;

[0054] Step S102: Close the water inlet solenoid valve, the air inlet solenoid valve, the first pressure relief solenoid valve and the second pressure relief solenoid valve and keep them de-energized;

[0055] Step S103: Set the pressure at the gas supply end of the gas storage device to the preset maximum pressure;

[0056] Step S104: Start the high-pressure water pump and set the outlet pressure of the high-pressure water pump to the preset maximum pressure;

[0057] Step S105: Manually open the water inlet solenoid valve or the air inlet solenoid valve, and simultaneously energize the water inlet solenoid valve, the air inlet solenoid valve, the first pressure relief solenoid valve and the second pressure relief solenoid valve to make the system enter the oscillation pressure unblocking mode. The oscillation pressure unblocking mode includes alternating first set of triggering operations and second set of triggering operations.

[0058] Step S106: When the system exits the oscillation and pressure unblocking mode and water-side pressurization or air-side pressurization cannot be stopped, it is determined that the hollow conduit to be unblocked has been unblocked.

[0059] The first set of triggering operations includes: when the water pressure reaches the preset maximum pressure, the inlet pressure switch outputs a disconnect signal and triggers the closure of the inlet solenoid valve and the second pressure relief solenoid valve to stop water-side pressurization; if the air pressure is not higher than the preset minimum pressure at this time, the inlet pressure switch outputs a closing signal and triggers the opening of the inlet solenoid valve and the first pressure relief solenoid valve to start air-side pressurization. The second set of triggering operations includes: when the air pressure reaches the preset maximum pressure, the inlet pressure switch outputs a disconnect signal and triggers the closure of the inlet solenoid valve and the first pressure relief solenoid valve to stop air-side pressurization; if the water pressure is not higher than the preset minimum pressure at this time, the inlet pressure switch outputs a closing signal and triggers the opening of the inlet solenoid valve and the second pressure relief solenoid valve to start water-side pressurization.

[0060] It is understandable that if the water inlet solenoid valve is manually opened in step S105, and the water inlet solenoid valve, the air inlet solenoid valve, the first pressure relief solenoid valve and the second pressure relief solenoid valve are simultaneously energized, the first set of triggering operations will be performed first, and then the second set of triggering operations will be performed, thereby entering the oscillation and pressure unblocking mode.

[0061] If the air intake solenoid valve is manually opened in step S105, and the water intake solenoid valve, the air intake solenoid valve, the first pressure relief solenoid valve, and the second pressure relief solenoid valve are simultaneously energized, the second set of triggering operations will be performed first, followed by the first set of triggering operations, thereby entering the oscillation and compression unblocking mode.

[0062] In order to remove foreign objects from the hollow conduit to be cleared, in some embodiments of this application, after determining that the hollow conduit to be cleared has been cleared, the method further includes:

[0063] Stop the system, remove the connector at the second end of the hollow conduit to be cleared, and start the high-pressure water pump to flush out the foreign objects from the hollow conduit.

[0064] Optionally, use white gauze to catch the expelled foreign objects and analyze their composition. This will help identify the cause of the blockage and improve prevention and maintenance.

[0065] To further confirm the reliability of the hollow conduit after it has been cleared, in some embodiments of this application, after the high-pressure water pump is started to flush out the foreign objects in the hollow conduit, a preset electrical test, an airtightness test, and a flow test are performed on the hollow conduit.

[0066] Optionally, the preset electrical tests include insulation, dielectric loss and AC withstand voltage tests, and the pass standard for the flow test is: the maximum value minus the minimum value divided by the minimum value does not exceed 15%.

[0067] To confirm the blockage status of the hollow conduit to be cleared, in some embodiments of this application, before heating the internal cooling water in the internal cooling water tank to a preset temperature, the method further includes:

[0068] The system continuously blows the tube at the second end of the hollow conduit to be cleared a preset number of times at the preset maximum pressure, and observes whether airflow is generated at the first end of the hollow conduit to be cleared. If not, the blowing is stopped.

[0069] The system continuously pressurizes the first end of the hollow conduit to be cleared at the preset maximum pressure a preset number of times, with each pressurization lasting for a preset duration, and observes whether water flows out from the second end of the hollow conduit to be cleared. If not, the pressurization is stopped.

[0070] Optional, the preset duration is 60 seconds.

[0071] Understandably, if airflow is generated at the first end of the hollow conduit to be cleared during gas pressurization, or water flows out at the second end of the hollow conduit to be cleared during water pressurization, it is confirmed that the hollow conduit to be cleared is not completely blocked. The system can be stopped, the connector at the second end of the hollow conduit to be cleared can be removed, and the high-pressure water pump can be started to flush out the foreign objects in the hollow conduit to be cleared. If the foreign objects are not flushed out, the oscillation and compression clearing mode can be continued to clear the blockage.

[0072] It is understandable that the order of steps S101 and S102 can be interchanged, and the order of steps S103 and S104 can be interchanged.

[0073] To further illustrate the technical concept of this invention, the technical solution of this invention will now be described in conjunction with specific application scenarios.

[0074] 1. Single-sided pressure application of the bar wire

[0075] 1. For example Figure 1 As shown, weld the second end of the hollow conduit 11 to be cleared in the target stator bar 10 to the external copper pipe. Repeatedly pressurize with nitrogen from the gas storage device 33, maintaining the pressure at approximately 1.8 MPa (see the inlet pressure switch), and perform three consecutive blow-through cycles. Observe whether airflow is generated at the first end of the hollow conduit 11. If there is no effect, stop pressurizing.

[0076] 2. Using qualified demineralized water (heated to 80-100℃), flush the hollow conduit 11 from the first end using a high-pressure water pump 23, maintaining the pressure below 1.8MPa. Hold the pressure for 60 seconds each time, then depressurize and repeat the pressurization process three times. Observe whether water flows from the second end of the hollow conduit 11. If there is no effect, stop pressurizing.

[0077] II. Use the vibration and pressure dredging mode for dredging.

[0078] 1. According to Figure 2 Connect all circuits as shown, but keep the power switch QS off.

[0079] The upper limit of the inlet pressure switch 21 and the air pressure switch 31 is set to 1.8MPa. Once the inlet pressure or air pressure reaches the upper limit, the current output signal of the inlet pressure switch 21 or the air pressure switch 31 will stop.

[0080] The lower limit of the inlet water pressure switch 21 and the inlet air pressure switch 31 is set to 0.1MPa. Once the inlet water pressure or inlet air pressure drops to the lower limit, the current output signal of the inlet water pressure switch 21 or the inlet air pressure switch 31 will stop.

[0081] 2. Heat the internal cooling water (qualified demineralized water, pH=8, conductivity<2μs / L) in the internal cooling water tank 24 to about 90℃.

[0082] 3. Close all of the following valves: water inlet solenoid valve 22, air inlet solenoid valve 32, first pressure relief solenoid valve 25, and second pressure relief solenoid valve 34.

[0083] 4. Open the nitrogen cylinder valve and control the nitrogen pressure at 1.8 MPa using the pressure reducing valve.

[0084] 5. Start the high-pressure water pump 23 and set the maximum outlet pressure of the high-pressure water pump 23 to 1.8 MPa.

[0085] 6. After manually opening the intake solenoid valve 32, quickly turn on the power switch QS.

[0086] according to Figure 2 The circuit control logic automatically enters the oscillation and compression unblocking mode:

[0087] like Figure 4 As shown, manually open the air intake solenoid valve 32. When the air pressure is ≥1.5Mpa and the water pressure is ≤0.1Mpa, power switch QS is turned on. If the air pressure is ≥1.8Mpa and the water pressure is ≤0.1Mpa, the air intake solenoid valve 32 and the first pressure relief solenoid valve 25 are closed, while the water intake solenoid valve 22 and the second pressure relief solenoid valve 34 are open. If the air pressure is ≤0.1Mpa and the water pressure is ≥1.8Mpa, the air intake solenoid valve 32 and the first pressure relief solenoid valve 25 are open, while the water intake solenoid valve 22 and the second pressure relief solenoid valve 34 are closed. If the air pressure is ≥1.8Mpa and the water pressure is ≤0.1Mpa, the air intake solenoid valve 32 and the first pressure relief solenoid valve 25 are closed, while the water intake solenoid valve 22 and the second pressure relief solenoid valve 34 are open. This achieves unblocking of the hollow conduit 11 using the vibration and pressure unblocking mode.

[0088] When the pressure on both sides of the hollow conduit 11 to be cleared approaches the same level and the phenomenon of unstoppable pressure loading on one side occurs, it indicates that the hollow conduit 11 to be cleared has been cleared. The connector at the second end of the hollow conduit 11 to be cleared can be removed, and the blockage can be flushed out with a high-pressure water pump 23.

[0089] By applying the above technical solutions, not only can the blocked stator bars of the generator be cleared, but they can also be used to clean the inside of the generator stator bars, enhance the generator's full-load capacity, reduce the generator's operating temperature, and extend the generator's lifespan.

[0090] The following explanation uses test data from a power plant as an example.

[0091] After conducting flow tests on the stator bars of a generator in a power plant, it was found that the unqualified bars were the upper layer bars 12# (air flow rate of 4.8 m / s) and 21# (air flow rate of 5.04 m / s), and the lower layer bar 46# (air flow rate of 3.6 m / s).

[0092] After clearing the stator bars using the oscillating pressure clearing mode, the air flow rate of upper layer bar #12 was 6.3 m / s, the air flow rate of upper layer bar #21 was 6.1 m / s, and the air flow rate of lower layer bar #46 was 6.3 m / s. This shows that all three stator bars have been cleared.

[0093] Finally, it should be noted that the above 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.

Claims

1. A power generator stator bar de-clogging system, characterized by, The water inlet pressure switch, the power switch, the first contactor, the second contactor, the air inlet pressure switch, the water inlet electromagnetic valve, the air inlet electromagnetic valve, the first pressure relief electromagnetic valve, the second pressure relief electromagnetic valve, the high-pressure water pump, the internal cooling water tank and the gas storage device are connected, wherein One end of the water inlet pressure switch is communicated with the first end of the hollow conduit to be dredged of the target stator bar, two ends of the water inlet electromagnetic valve are respectively communicated with the other end of the water inlet pressure switch and the outlet of the high-pressure water pump, the inlet of the high-pressure water pump is communicated with the internal cooling water tank, one end of the air inlet pressure switch is communicated with the second end of the hollow conduit to be dredged, two ends of the air inlet electromagnetic valve are respectively communicated with the other end of the air inlet pressure switch and the gas supply end of the gas storage device, the first pressure relief electromagnetic valve is used for discharging pressure medium from the first end of the hollow conduit to be dredged, and the second pressure relief electromagnetic valve is used for discharging pressure medium from the second end of the hollow conduit to be dredged, wherein one end of the first pressure relief electromagnetic valve is communicated with the pipeline between the water inlet pressure switch and the water inlet electromagnetic valve and the other end is vented, and one end of the second pressure relief electromagnetic valve is communicated with the pipeline between the air inlet pressure switch and the air inlet electromagnetic valve and the other end is vented; The power switch is used for power supply or power cut of the water inlet pressure switch, the air inlet pressure switch, the water inlet electromagnetic valve, the air inlet electromagnetic valve, the first pressure relief electromagnetic valve and the second pressure relief electromagnetic valve; The first contactor is used for realizing linkage of the water inlet pressure switch, the water inlet electromagnetic valve and the second pressure relief electromagnetic valve; The second contactor is used for realizing linkage of the air inlet pressure switch, the air inlet electromagnetic valve and the first pressure relief electromagnetic valve; The live wire and the zero line on one side of the power switch are connected with the power supply, the water inlet pressure switch, the coil of the first contactor and the normally closed contact of the second contactor are connected in series between the live wire and the zero line on the other side of the power switch, the air inlet pressure switch, the coil of the second contactor and the normally closed contact of the first contactor are connected in series between the live wire and the zero line on the other side of the power switch, the air inlet electromagnetic valve and the first pressure relief electromagnetic valve are connected with the live wire and the zero line on the other side of the power switch through the main contact of the second contactor, and the water inlet electromagnetic valve and the second pressure relief electromagnetic valve are connected with the live wire and the zero line on the other side of the power switch through the main contact of the first contactor; The water inlet pressure switch is disconnected when the water pressure at the first end of the hollow conduit to be dredged reaches the preset maximum pressure, and triggers the water inlet electromagnetic valve and the second pressure relief electromagnetic valve to be closed, the water inlet pressure switch is closed when the water pressure is not higher than the preset minimum pressure, and triggers the water inlet electromagnetic valve and the second pressure relief electromagnetic valve to be opened, the air inlet pressure switch is disconnected when the air pressure at the second end of the hollow conduit to be dredged reaches the preset maximum pressure, and triggers the air inlet electromagnetic valve and the first pressure relief electromagnetic valve to be closed, and the air inlet pressure switch is closed when the air pressure is not higher than the preset minimum pressure, and triggers the air inlet electromagnetic valve and the first pressure relief electromagnetic valve to be opened.

2. The system of claim 1, wherein, The high-pressure water pump is provided with a filter screen in front of the inlet, the gas storage device contains nitrogen, the gas supply end of the gas storage device is provided with a pressure reducing valve, and the inner cooling water tank is provided with a heating device.

3. The system of claim 1, wherein, The target stator bar is one stator bar of the generator or all stator bars of the generator, the preset maximum pressure is a first preset pressure when the target stator bar is one stator bar of the generator, and the preset maximum pressure is a second preset pressure when the target stator bar is all stator bars of the generator, and the first preset pressure is higher than the second preset pressure.

4. A method of debridement control of a generator stator bar, characterized by, The method is applied to the system of any one of claims 1-3, and the method comprises: warming the inner cooling water in the inner cooling water tank to a preset temperature; closing and keeping off the water inlet electromagnetic valve, the gas inlet electromagnetic valve, the first pressure relief electromagnetic valve and the second pressure relief electromagnetic valve; setting the pressure of the gas supply end of the gas storage device to the preset maximum pressure; starting the high-pressure water pump and setting the outlet pressure of the high-pressure water pump to the preset maximum pressure; manually opening the water inlet electromagnetic valve or the gas inlet electromagnetic valve, and simultaneously powering on the water inlet electromagnetic valve, the gas inlet electromagnetic valve, the first pressure relief electromagnetic valve and the second pressure relief electromagnetic valve, so that the system enters a shock and compression dredging mode, and the shock and compression dredging mode comprises a first group of trigger operations and a second group of trigger operations alternately performed; when the system exits the shock and compression dredging mode and water side pressurization or gas side pressurization cannot be stopped, it is determined that the to-be-dredged hollow conduit has been dredged; the first group of trigger operations comprises that when the water pressure reaches the preset maximum pressure, the water pressure switch outputs an open signal and triggers the water inlet electromagnetic valve and the second pressure relief electromagnetic valve to be closed, so as to stop water side pressurization, and if the gas pressure is not higher than the preset minimum pressure at this time, the gas pressure switch outputs a closed signal and triggers the gas inlet electromagnetic valve and the first pressure relief electromagnetic valve to be opened, so as to start gas side pressurization; the second group of trigger operations comprises that when the gas pressure reaches the preset maximum pressure, the gas pressure switch outputs an open signal and triggers the gas inlet electromagnetic valve and the first pressure relief electromagnetic valve to be closed, so as to stop gas side pressurization, and if the water pressure is not higher than the preset minimum pressure at this time, the water pressure switch outputs a closed signal and triggers the water inlet electromagnetic valve and the second pressure relief electromagnetic valve to be opened, so as to start water side pressurization.

5. The method of claim 4, wherein, After it is determined that the to-be-dredged hollow conduit has been dredged, the method further comprises: stopping the system, removing the connector of the second end of the to-be-dredged hollow conduit, and starting the high-pressure water pump to flush out the foreign matter in the to-be-dredged hollow conduit.

6. The method of claim 4, wherein, After starting the high-pressure water pump to flush out the foreign matter in the to-be-dredged hollow conduit, preset electrical tests, air tightness tests and flow tests are performed on the to-be-dredged hollow conduit.

7. The method of claim 4, wherein, Before warming the inner cooling water in the inner cooling water tank to a preset temperature, the method further comprises: Based on the system, the second end of the hollow conduit to be dredged is continuously blown for a preset number of times at the preset maximum pressure, and it is observed whether air flow is generated at the first end of the hollow conduit to be dredged. If not, stop blowing; Based on the system, the first end of the hollow conduit to be dredged is continuously pressurized for a preset number of times at the preset maximum pressure, and each time the pressure holding duration reaches the preset duration, and it is observed whether water is discharged at the second end of the hollow conduit to be dredged. If not, stop pressurizing.

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