Water blowing method for internal water cooling generator stator

Abstract

The invention relates to a water blowing method for a stator of an internal water cooling generator, which comprises the following steps of: blocking a stator cooling water inlet pipe of the generator when a stator cooling pump of the generator is stopped, an inlet / outlet valve is closed and clean water is discharged through an opened stator cooling water discharge door; a sealing piece of a stator cooling water outlet pipe of the generator is detached, a pipe joint is connected to the side of a generator body, and a pressure gauge is arranged on the pipe joint; plugging a stator cooling water outlet pipe, and plugging an outlet water return pipe of the generator; compressed air for instruments is connected to a pipe connector of a stator cooling water drainage door through a hose, water is blown through compressed air provided by the compressed air for instruments, and real-time pressure is monitored at the water blowing position of stator cooling water of the generator so that the real-time pressure can be not larger than a set pressure threshold value, and clean drainage is achieved. By means of the method, the water blowing process is safe and reliable in operation, and the operation risk is greatly reduced. Meanwhile, the scheme is simple in operation process, low in maintenance cost and high in maintenance efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of generators with internal water cooling of stator bars and dead-grounded collecting pipes, and specifically, the present invention relates to a method for blowing water from the stator of a water-cooled generator. Background Art

[0002] For water-hydrogen-hydrogen cooled, self-excited static excitation generator sets, it is necessary to blow water for electrical tests during each shutdown and maintenance period. The "Regulations for Preventive Tests of Electric Equipment" DL / T596-2021 stipulates the leakage current and DC withstand voltage of the stator winding. For water-cooled generators with insulated collecting pipes, the low-voltage shielding method should be used for wiring; for generators with dead-grounded collecting pipes, the test should be carried out as much as possible under the conditions of no water flow and the blowing clean of the water inlet pipes.

[0003] For dead-grounded generators, it is necessary to blow the water in the stator bars clean before performing DC leakage and withstand voltage tests. In the past, according to the method guided by the manufacturer's instructions, the inlet pipe of the stator cooling water was disassembled, and compressed air was introduced from the inlet of the stator cooling water for blowing water. The water outlets at the lower excitation end, steam end, and the outlet pipes of the stator leads were drained alternately. The workload was large and the efficiency was low. Usually, it was necessary to blow water continuously for 72 hours or more to meet the insulation measurement conditions. Only after the insulation and absorption ratio were qualified could the leakage current and DC withstand voltage of the stator winding be carried out, which seriously restricted the maintenance progress of the generator and even affected the normal start-up of the unit in the later stage of maintenance. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for blowing water from the stator of a water-cooled generator, aiming to solve at least one of the above technical problems.

[0005] In a first aspect, the technical solution of the present invention for solving the above technical problem is as follows: A method for blowing water from the stator of a water-cooled generator, the method comprising:

[0006] When the stator cooling water pump of the generator is stopped, the inlet and outlet valves are closed, and the water has been drained through the opened stator cooling water drain valve, the inlet pipe of the stator cooling water of the generator is blocked;

[0007] The seal of the outlet pipe of the stator cooling water of the generator is disassembled, a pipe joint is connected on the side of the generator body, and a pressure gauge is provided on the pipe joint;

[0008] The outlet pipe of the stator cooling water is blocked, and the outlet pipe of the generator lead is blocked;

[0009] Instrument air is connected to the pipe joint of the stator cooling water drain valve through a hose, and the compressed air provided by the instrument air is used for blowing water, and the real-time pressure is monitored from the water blowing place of the stator cooling water of the generator, so that the real-time pressure is not greater than the set pressure threshold to achieve clean drainage.

[0010] The beneficial effects of the present invention are as follows: Instrument air is introduced through the drain valve of the stator cooling water of the generator for purging. During the whole process, the operating pressure is low, basically lower than the rated inlet water pressure of the generator, making the purging process safe and reliable in operation and greatly reducing the operation risk. At the same time, the operation process of this solution is simple. It is simple and convenient to disassemble the inlet pipeline of the stator cooling water of the generator to add a pressure gauge and connect the instrument air source pipe near the generator. In addition, only 2 generator maintenance workers are required to cooperate with each other in this solution, and it can be completed within 1 working day, resulting in low maintenance costs. Moreover, it only takes about 7 hours to complete the purging through this solution, greatly improving the maintenance efficiency and shortening the maintenance period.

[0011] Based on the above technical solutions, the present invention can be further improved as follows.

[0012] Further, a high-strength hose is used to connect the instrument air to the pipe joint of the drain valve of the stator cooling water.

[0013] Further, the drain valve of the stator cooling water includes a drain valve for the steam end stator cooling water, a drain valve for the outgoing line stator cooling water, and a drain valve for the exciter end stator cooling water.

[0014] Further, the instrument air is connected to the pipe joint of the drain valve of the stator cooling water through a hose, and purging is carried out by the compressed air provided by the instrument air. The real-time pressure is monitored at the purging point of the stator cooling water of the generator so that the real-time pressure does not exceed the set pressure threshold to achieve clean drainage, including:

[0015] Take the pipe joint of any one of the drain valves of the steam end stator cooling water, the drain valve of the outgoing line stator cooling water, and the drain valve of the exciter end stator cooling water as the purging pipe, connect the compressed air provided by the instrument air, open the valves of the other two drain valves of the stator cooling water, switch one drain valve of the stator cooling water as the purging pipe every half hour, continuously operate for the first period of time, and monitor the real-time pressure at the purging point of the stator cooling water of the generator. Control the real-time pressure within the first pressure range until there is no water droplet at the pipe orifice of the pipe joint of each drain valve of the stator cooling water to stop purging. The pressure values corresponding to the first pressure range are not greater than the set pressure threshold.

[0016] Further, after there is no water droplet at the pipe orifice of the pipe joint of each drain valve of the stator cooling water to stop purging, the method further includes:

[0017] Take any one of the stator cooling water drain valves at the turbine end, the outgoing line stator cooling water drain valve, and the exciter end stator cooling water drain valve as the blow pipe, connect it to the compressed air provided by the instrument air, close one of the valves of the other two stator cooling water drain valves, open the valve of the remaining one stator cooling water drain valve, switch one stator cooling water drain valve as the blow pipe every half hour, continuously operate for a second period of time, and monitor the real-time pressure at the blow water point of the generator stator cooling water. Control the real-time pressure within a second pressure range until there is no water mist in the blown air and stop blowing water. The pressure values corresponding to the second pressure range are all greater than the set pressure threshold.

[0018] Further, the plugging of the incoming pipe of the stator cooling water of the generator includes:

[0019] Disassemble the first flange of the incoming pipe of the stator cooling water of the generator, install a 3-mm thick blanking plate, and then restore the first flange.

[0020] Further, the seals of the outgoing pipe of the stator cooling water of the generator are the first flange and the second flange of the outgoing pipe of the stator cooling water.

[0021] Further, the plugging of the outgoing pipe of the stator cooling water and the plugging of the outgoing line return pipe of the generator include:

[0022] Install a blanking plate to seal the outgoing pipe of the stator cooling water, and disassemble the pipe joint of the outgoing line return pipe of the generator and install a blanking plate.

[0023] Further, the set pressure threshold is 0.2 MPa.

[0024] Further, the first pressure range is 0.1 - 0.2 MPa, and the second pressure range is 0.2 - 0.3 MPa.

[0025] Additional aspects and advantages of the present application will be given in part in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention.

[0027] Figure 1 It is a schematic flow chart of a method for blowing water from the stator of a water-cooled generator provided by an embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of a generator stator cooling water system provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The principles and features of the present invention will be described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0030] The technical solutions of the present invention and how the technical solutions of the present invention solve the above technical problems will be described in detail below with specific embodiments. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0031] The solution provided by the embodiment of the present invention can be applied to any application scenario that requires water blowing based on a dead-earthed generator.

[0032] The embodiment of the present invention provides a possible implementation manner. As Figure 1 shown, a flowchart of a method for blowing water from the stator of a water-cooled generator is provided. As Figure 1 shown in the flowchart, the method may include the following steps:

[0033] S10. When the stator cooling water pump of the generator is stopped, the inlet and outlet valves are closed, and the water has been drained completely through the opened stator cooling water drain valve, block the stator cooling water inlet pipe of the generator;

[0034] S20. Disassemble the seal of the stator cooling water outlet pipe of the generator, connect a pipe joint on the generator body side, and a pressure gauge is provided on the pipe joint;

[0035] S30. Block the stator cooling water outlet pipe and block the outgoing line return water pipe of the generator;

[0036] S40. Connect instrument air through a hose to the pipe joint of the stator cooling water drain valve, blow water with the compressed air provided by the instrument air, and monitor the real-time pressure at the water blowing place of the stator cooling water of the generator, so that the real-time pressure is not greater than the set pressure threshold to achieve clean drainage.

[0037] By the method of the present invention, instrument air is introduced through the stator cooling water drain valve of the generator for purging. During the whole process, the operating pressure is low, basically lower than the rated inlet pressure of the generator, making the water blowing process safe and reliable in operation and greatly reducing the operation risk. At the same time, the operation process of this solution is simple. It is simple and convenient to disassemble the stator cooling water inlet pipe of the generator to add a pressure gauge and connect the instrument air source pipe near the generator. In addition, only 2 generator maintenance workers are required to cooperate with each other for this solution, and it can be completed within 1 working day, resulting in low maintenance costs. And, it only takes about 7 hours to complete the water blowing through this solution, greatly improving the maintenance efficiency and shortening the maintenance period.

[0038] The following further describes the solution of the present invention in combination with the following specific embodiments. In this embodiment, in combination with Figure 2 As shown in the schematic diagram of a generator stator cooling water system, based on this system, a method for blowing water from the stator of a water-cooled generator may include the following steps:

[0039] S10. When the stator cooling water pump of the generator is stopped, the inlet and outlet valves are closed, and the water has been drained completely through the opened stator cooling water drain valve, block the stator cooling water inlet pipe of the generator.

[0040] Among them, the generator can be a dead-grounded generator. Draining the water completely through the opened stator cooling water drain valve means that only by opening the stator cooling water drain valve and letting the water drain by itself, without performing other auxiliary drainage operations.

[0041] Optionally, the stator cooling water drain valve includes a steam-end stator cooling water drain valve, a lead-out stator cooling water drain valve, and an exciter-end stator cooling water drain valve. Among them, the exciter-end stator cooling water drain valve can be a manual drain valve, and the lead-out stator cooling water drain valve can also be a manual drain valve.

[0042] Optionally, the blocking of the stator cooling water inlet pipe of the generator includes:

[0043] Disassemble the first flange of the stator cooling water inlet pipe of the generator, install a 3-mm thick blanking plate, and then restore the first flange.

[0044] S20. Disassemble the seal of the stator cooling water outlet pipe of the generator, connect a pipe joint on the generator body side, and a pressure gauge is provided on the pipe joint.

[0045] Optionally, the seal of the stator cooling water outlet pipe of the generator is the first flange and the second flange of the stator cooling water outlet pipe.

[0046] Among them, the measuring range of the pressure gauge can be 0 to 1.0 MPa. The pressure corresponding to the compressed air during the water blowing process can be monitored in real time through the pressure gauge.

[0047] S30. Block the stator cooling water outlet pipe and block the generator lead-out return water pipe.

[0048] Optionally, the blocking of the stator cooling water outlet pipe and the blocking of the generator lead-out return water pipe include: installing a blanking plate to seal the stator cooling water outlet pipe, and disassembling the pipe joint of the generator lead-out return water pipe and installing a blanking plate.

[0049] S40. Connect the instrument air compressor to the pipe joint of the demineralized water drain valve of the generator through a hose, blow the water with the compressed air provided by the instrument air compressor, and monitor the real-time pressure at the water blowing point of the generator demineralized water, so that the real-time pressure does not exceed the set pressure threshold to achieve clean drainage.

[0050] Optionally, a high-strength hose (with a pressure resistance range of not less than 1.0 MPa) can be used to connect the instrument air compressor to the pipe joint of the demineralized water drain valve.

[0051] Optionally, the above S40 can be divided into two stages:

[0052] First stage: Take the pipe joint of any one of the demineralized water drain valves of the steam end demineralized water drain valve, the outgoing line demineralized water drain valve, and the exciter end demineralized water drain valve as the water blowing pipe, connect it to the compressed air provided by the instrument air compressor, open the valves of the other two demineralized water drain valves, switch one demineralized water drain valve as the water blowing pipe every half hour, continuously operate for the first period of time, and monitor the real-time pressure at the water blowing point of the generator demineralized water, control the real-time pressure within the first pressure range until there are no water droplets at the nozzle of the pipe joint of each demineralized water drain valve to stop blowing water. The pressure values corresponding to the first pressure range are all not greater than the set pressure threshold.

[0053] Among them, the set pressure threshold is 0.2 MPa. The first pressure range is 0.1 - 0.2 MPa.

[0054] As an example, take the pipe joint of the steam end demineralized water drain valve among the steam end demineralized water drain valve, the outgoing line demineralized water drain valve, and the exciter end demineralized water drain valve as the water blowing pipe, open the two drain valves of the outgoing line demineralized water drain valve and the exciter end demineralized water drain valve, start the first round of water blowing. During the water blowing process, connect the compressed air provided by the instrument air compressor to the water blowing pipe, so that the water is discharged from the two drain valves of the outgoing line demineralized water drain valve and the exciter end demineralized water drain valve. And during the water blowing process, continuously monitor the real-time pressure at the water blowing point of the generator demineralized water, control the real-time pressure within the first pressure range. After half an hour, the pipe joint of the outgoing line demineralized water drain valve among the steam end demineralized water drain valve, the outgoing line demineralized water drain valve, and the exciter end demineralized water drain valve can be used as the water blowing pipe, then open the two drain valves of the steam end demineralized water drain valve and the exciter end demineralized water drain valve, start the second round of water blowing, and the second round of water blowing can also last for half an hour. After that, take the pipe joint of the exciter end demineralized water drain valve as the water blowing pipe, open the steam end demineralized water drain valve and the outgoing line demineralized water drain valve, and conduct the third round of water blowing. According to the above process, continuously blow water for the first period of time (for example, 2 hours) until there are no water droplets at the nozzle of the pipe joint of each demineralized water drain valve to stop blowing water.

[0055] To further drain the water completely, the following second-stage drainage can also be carried out.

[0056] Second stage: Select any one of the stator cooling water drain valves at the steam end, outgoing line, and exciter end as the blow pipe, connect it to the compressed air provided by the instrument air, close one of the valves of the other two stator cooling water drain valves, open the valve of the remaining one stator cooling water drain valve, switch one stator cooling water drain valve as the blow pipe every half hour, continuously operate for a second period of time, and monitor the real-time pressure at the blow water point of the generator stator cooling water, control the real-time pressure within a second pressure range until there is no water mist in the blown air and stop blowing water. The pressure values corresponding to the second pressure range are all greater than the set pressure threshold.

[0057] Wherein, the second pressure range is 0.2 - 0.3 MPa.

[0058] As an example, take the pipe joint of the stator cooling water drain valve at the steam end among the stator cooling water drain valves at the steam end, outgoing line, and exciter end as the blow pipe, close the drain valve of the outgoing line stator cooling water, open the drain valve of the exciter end stator cooling water, and start the first round of blowing water. During the blowing water process, connect the compressed air provided by the instrument air to the blow pipe, so that the water is discharged from the drain valve of the outgoing line stator cooling water. And during the blowing water process, continuously monitor the real-time pressure at the blow water point of the generator stator cooling water, control the real-time pressure within the second pressure range. After half an hour, the pipe joint of the drain valve of the outgoing line stator cooling water can be used as the blow pipe, then close the drain valve of the steam end stator cooling water, open the drain valve of the exciter end stator cooling water, and start the second round of blowing water. The second round of blowing water can also last for half an hour. After that, take the pipe joint of the drain valve of the exciter end stator cooling water as the blow pipe, close the drain valve of the steam end stator cooling water, open the drain valve of the outgoing line stator cooling water, and conduct the third round of blowing water. According to the above process, continuously blow water for the second period of time (for example, 5 hours) until there is no water mist in the blown air and stop blowing water. Specifically, a humidity detector can be used to detect that the humidity is below 50% to judge to stop blowing water.

[0059] In the solution of this application, during the blowing water process, one person can operate the valves to repeatedly open and close these two drain valves alternately, and one person can monitor and supervise the pressure gauge pipe joint, etc. In this way, only two operators are required for the whole process.

[0060] Furthermore, the Figure 2 system can be improved: A rubber inlet pipe, a dryer, a filter, and a pressure gauge can be added to the original generator pipeline. A balance pipe is connected between the stator cooling water inlet pipe and the stator cooling water outlet pipe, and a first balance pipe valve and a second balance pipe valve are installed on the balance pipe. A pressure gauge is installed at one end of the rubber inlet pipe close to the balance pipe, and a first inlet pipe valve is installed between the rubber inlet pipe and the balance pipe. A dryer and a filter are installed in sequence at the end of the rubber inlet pipe far from the balance pipe.

[0061] Based on the above improved system, the second stage in S40 above can be further optimized:

[0062] Step 1: Drain the stator cooling water:

[0063] Close the stator cooling water inlet pipe valve and the stator cooling water outlet pipe valve, open the first drain pipe valve, the second drain pipe valve, the third drain pipe valve, and the fourth drain pipe valve to drain the stator cooling water.

[0064] Among them, the first drain pipe valve is located on the inlet pipe of the stator cooling water system, near the generator inlet. During the system filling or flushing process, it is used to discharge the air in the inlet pipe to prevent air accumulation from affecting the water flow and pressure; the second drain pipe valve is located on the outlet pipe of the stator cooling water system, near the generator outlet. During the system operation or flushing process, it is used to discharge the air in the outlet pipe to ensure smooth water flow; the third drain pipe valve is located on the manifold of the stator cooling water system and is used to balance the pressure in the system. When the system is out of water, it prevents the cooling water from flowing back due to the siphon effect and protects the internal components of the generator; the fourth drain pipe valve is located at other key positions in the stator cooling water system, such as on the bypass pipe of the ion exchanger or filter; during the system maintenance or flushing process, it is used to discharge the air or excess moisture in the pipe to ensure the stability and safety of the system operation;

[0065] Step 2: Purge the intake pipe:

[0066] First, suspend one end of the rubber intake pipe in the air, open the dryer, the filter, and the second intake pipe valve, and purge the rubber intake pipe until the air discharged from the rubber intake pipe is pure.

[0067] Among them, the first intake pipe valve is usually located at the front end of the intake system and is connected to an external air source (instrument air). It is the first control point in the intake system and is used to control the flow rate and pressure of the air source entering the system, that is, the valve of the blow water pipe described in the previous text; during the flushing process, the first intake pipe valve is used to control the pressure and flow rate of the air source entering the system to ensure the stability and safety of the flushing process. It can adjust the pressure of the air source to keep it within the set safety range and avoid damaging the generator stator bars.

[0068] The second intake pipe valve is located in the middle of the intake system, usually after the first intake pipe valve. It is connected to the intake pipe of the generator stator cooling water system and is used to further control the pressure of the gas source entering the stator bars. During the water blowing process, the second intake pipe valve is used to further adjust the pressure of the gas source to ensure the efficiency and safety of the water blowing process. It can control the specific position where the gas source enters the stator bars to ensure uniform distribution of the air flow and improve the water blowing effect. In the solution of this application, on the side of the water blowing pipe, a first intake pipe valve and a second intake pipe valve can be provided. During the water blowing process, both valves are in the open state.

[0069] Step 3: Close the drain pipe valve:

[0070] Close the first drain pipe valve, the second drain pipe valve, the third drain pipe valve, and the fourth drain pipe valve, and confirm that the second balance pipe valve is in the open state.

[0071] Step 4: Introduce dried instrument air:

[0072] Open the second intake pipe valve, the first intake pipe valve, and the pressure gauge valve in sequence, and introduce the dried instrument air (compressed air provided by instrument compressed air) into the stator bars.

[0073] Step 5: Introduce dried instrument air again:

[0074] Open the first balance pipe valve, and introduce the dried instrument air into the stator bars again until there is no water mist in the first drain pipe valve, the second drain pipe valve, the third drain pipe valve, and the fourth drain pipe valve.

[0075] Furthermore, an air heating device can be added to the water blowing system to perform purging with heated air to reduce the influence of condensation in the cooling water circuit on the insulation. Through the electric heating tube and the temperature control system, ensure that the blowing temperature is within an appropriate range to improve the drying efficiency.

[0076] To better illustrate and understand the principle of the method provided by the present invention, the solution of the present invention will be described below with reference to an optional specific embodiment. It should be noted that the specific implementation manners of each step in this specific embodiment should not be construed as a limitation to the solution of the present invention. Based on the principle of the solution provided by the present invention, other implementation manners that can be conceived by those skilled in the art should also be regarded as within the protection scope of the present invention.

[0077] The purpose of the solution of this application is to shorten the water blowing time of the generator stator bars, completely dry the accumulated water inside the generator stator bars within one working day during the generator overhaul, and initially measure that the insulation and absorption ratio of the generator are both in a good range, so that the DC withstand voltage leakage test can be carried out smoothly, greatly improving the overhaul progress and reducing the overhaul workload.

[0078] For the above reasons, this solution can be applied to generators with internal water cooling of stator bars and dead grounding of water collecting pipes, providing a safe, efficient, and low-cost method for blowing water on stator bars, water collecting rings, and water guiding pipes, greatly shortening the maintenance period, with remarkable effects and wide application value in the power industry.

[0079] In this embodiment, taking a power generation company as an example, in response to this problem, the site was deeply analyzed and studied to improve the water blowing method. After two on-site implementations and optimization of the operation method, remarkable effects were achieved.

[0080] During the A-class maintenance of Unit 3 in 2019, compressed air pipes were alternately connected to the three pipe orifices of water outlet at the excitation end, water outlet at the steam end, and stator outgoing line at the lower part of Generator 3. The other two pipes were blown with water alternately in single-open or double-open modes. The operation took 18 hours to complete the water blowing of the generator stator bars, and the insulation absorption ratio of the generator was qualified.

[0081] During the C-class maintenance of Unit 4 in 2019, compressed air pipes were alternately connected to the three pipe orifices of water outlet at the excitation end, water outlet at the steam end, and stator outgoing line at the lower part of Generator 4. The other two pipes were blown with water alternately in single-open or double-open modes. Special personnel were arranged for the operation. During the process, one person could operate the valves to alternately open and close the two drain valves repeatedly, and one person was responsible for monitoring and cooperating with operations such as the pressure gauge pipe joints. It took about 7 hours to dry the accumulated water inside the generator stator bars. The insulation and absorption ratio of the generator were initially measured to be in a good range, enabling the smooth progress of the DC withstand voltage leakage test, greatly improving the maintenance progress, and also reducing the maintenance workload and saving labor costs.

[0082] Through the solution of the present invention, compared with the prior art, it has the following beneficial effects:

[0083] (1) Instrument air is introduced for purging through the drain pipes below the manual valves for stator cooling water drainage at the steam end of the generator, manual valves for stator cooling water drainage at the outgoing line, and manual valves for stator cooling water drainage at the excitation end. During the whole process, the operating pressure is low, basically lower than the rated inlet water pressure of the generator, which is 0.31 Mpa. Compared with the manufacturer's method of blowing water under pressure (0.7 Mpa), the operation is safer and more reliable, greatly reducing the operation risk.

[0084] (2) The operation process is simple. It is simple and convenient to disassemble the stator cooling water inlet pipe of the generator to add a pressure gauge and connect the instrument air source pipe on the busbar platform near the generator.

[0085] (3) The maintenance cost is low. Only the cooperation of 2 generator maintenance workers is required, and it can be completed within 1 working day.

[0086] (4) The working efficiency is high. It only takes about 7 hours to complete the water blowing, greatly improving the maintenance efficiency and shortening the maintenance period.

[0087] The above description is only a preferred embodiment of the present invention and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of disclosure involved in the present invention is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) having similar functions disclosed in the present invention.

Claims

1. A method for blowing water on the stator of a water-cooled generator, characterized in that, It includes the following steps: When the stator cooling water pump of the generator is shut down, the inlet and outlet valves are closed, and the water has been drained completely through the opened stator cooling water drain valve, block the stator cooling water inlet pipe of the generator; Disassemble the seal of the stator cooling water outlet pipe of the generator, connect a pipe joint on the generator body side, and a pressure gauge is provided on the pipe joint; Block the stator cooling water outlet pipe and block the outgoing line return water pipe of the generator; Connect instrument air through a hose to the pipe joint of the stator cooling water drain valve, blow water with the compressed air provided by the instrument air, and monitor the real-time pressure at the water blowing place of the generator stator cooling water, so that the real-time pressure is not greater than the set pressure threshold to achieve clean drainage.

2. The method according to claim 1, characterized in that, Connect the instrument air to the pipe joint of the stator cooling water drain valve using a high-strength hose.

3. The method according to claim 1, wherein The stator cooling water drain valve includes a steam end stator cooling water drain valve, an outgoing line stator cooling water drain valve, and an excitation end stator cooling water drain valve.

4. The method according to claim 3, wherein The step of connecting instrument air through a hose to the pipe joint of the stator cooling water drain valve, blowing water with the compressed air provided by the instrument air, and monitoring the real-time pressure at the water blowing place of the generator stator cooling water, so that the real-time pressure is not greater than the set pressure threshold to achieve clean drainage, includes: Take the pipe joint of any one of the steam end stator cooling water drain valve, the outgoing line stator cooling water drain valve, and the excitation end stator cooling water drain valve as the water blowing pipe, connect the compressed air provided by the instrument air, open the valves of the other two stator cooling water drain valves, switch one stator cooling water drain valve as the water blowing pipe every half hour, continuously operate for the first period of time, and monitor the real-time pressure at the water blowing place of the generator stator cooling water, control the real-time pressure within the first pressure range until there is no water droplet at the pipe orifice of the pipe joint of each stator cooling water drain valve, then stop blowing water. The pressure values corresponding to the first pressure range are not greater than the set pressure threshold.

5. The method according to claim 4, wherein After there is no water droplet at the pipe orifice of the pipe joint of each stator cooling water drain valve and stop blowing water, the method further includes: Take any one of the steam end stator cooling water drain valve, the outgoing line stator cooling water drain valve, and the excitation end stator cooling water drain valve as the water blowing pipe, connect the compressed air provided by the instrument air, close one of the valves of the other two stator cooling water drain valves, open the valve of the remaining one stator cooling water drain valve, switch one stator cooling water drain valve as the water blowing pipe every half hour, continuously operate for the second period of time, and monitor the real-time pressure at the water blowing place of the generator stator cooling water, control the real-time pressure within the second pressure range until there is no water mist in the blown air, then stop blowing water. The pressure values corresponding to the second pressure range are greater than the set pressure threshold.

6. The method according to any one of claims 1 to 5, characterized in that, The step of blocking the stator cooling water inlet pipe of the generator includes: Disassemble the first flange of the stator cooling water inlet pipe of the generator, install a 3 mm thick blanking plate, and then restore the first flange.

7. The method according to any one of claims 1 to 5, characterized in that The seals of the stator cooling water outlet pipe of the generator are the first flange and the second flange of the stator cooling water outlet pipe.

8. The method according to any one of claims 1 to 5, characterized in that The step of blocking the stator cooling water outlet pipe and blocking the outgoing line return water pipe of the generator includes: Install a blanking plate to seal the outlet pipe of the stator cooling water, and disassemble the pipe joint of the outlet water return pipe of the generator to install a blanking plate.

9. The method according to claim 5, characterized in that, The set pressure threshold is 0.2 MPa.

10. The method according to claim 9, characterized in that, The first pressure range is 0.1 - 0.2 MPa, and the second pressure range is 0.2 - 0.3 MPa.

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