A method for flushing the fire-resistant oil (EH) system of a steam turbine in a power plant

Abstract

The present invention relates to the technical field of EH systems in power plants, and in particular to a flushing method for the EH system of a steam turbine in a power plant. When the EH system of a steam turbine in a power plant is overhauled, the oil motor is first removed for inspection, and a flushing device is installed in situ to ensure a stable connection with the EH system and a sealed interface. Next, the flushing medium is connected and the pressure and flow are scientifically set to ensure a stable high-flow flushing process. After starting the flushing process, the flushing medium is fully circulated in the EH system to effectively remove particulate matter and other pollutants. During the process, changes in the particle size of the oil product are continuously monitored until two consecutive sampling tests meet the standards. After meeting the standards, the flushing is turned off, the device is removed, and then preparations are made for reinstallation of the oil motor and verification testing of the valve switch function. This greatly improves the operational convenience of the system and significantly improves the flushing efficiency and effect of the entire EH system.

Description

Technical Field

[0001] The present invention relates to the technical field of EH oil systems in power plants, in particular to a method for flushing an EH oil system of a steam turbine in a power plant. Background Art

[0002] The EH oil system for power plant steam turbine fire-resistant fuels requires high oil cleanliness during operation, reaching MOOG Grade 2 or NAS Grade 5. Therefore, after unit overhauls or major system maintenance projects, system flushing is required to remove impurities. EH oil quality issues are often a key factor limiting power plant maintenance schedules.

[0003] Currently, the system flushing solutions offered by major equipment manufacturers all involve installing various flushing plates, which are divided into primary flushing (pipeline flushing), secondary flushing (motor flushing), and some systems require triple flushing. This flushing solution requires extensive disassembly and assembly of system equipment (such as solenoid valves, unloading valves, servo valves, etc.), orifices, and frequent replacement of flushing plates at each flushing stage, resulting in the following major issues:

[0004] (1) The program process involves many steps, the operation is cumbersome and time-consuming.

[0005] (2) When the pipeline is flushed (one-time flushing), the oil motor, test components, shut-off components, etc. that have been returned to the factory for flushing and are clean and qualified will be contaminated again.

[0006] (3) It is necessary to frequently disassemble and assemble the various system equipment and frequently replace various flushing plates, etc., which is very likely to cause problems such as missing installation, mixed installation, and installation errors. At the same time, large-scale disassembly and assembly of various equipment poses a greater risk of secondary pollution to the entire system.

[0007] (4) Due to the structural characteristics of the system equipment, the total flushing flow is limited, affecting the flushing effect.

[0008] In response to the above problems existing in conventional flushing, this project innovatively proposed an optimization plan for independent large-flow flushing of pipelines, and successfully implemented it during the overhaul of Unit 3 of the power plant. Summary of the Invention

[0009] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0010] In view of the problems in the above or existing technologies such as the complexity of single flushing (pipeline flushing), excessive equipment requiring frequent disassembly, and the susceptibility to secondary pollution, the present invention is proposed.

[0011] Therefore, an object of the present invention is to provide a method for flushing an extinguishing oil (EH) system of a steam turbine in a power plant.

[0012] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0013] Installation: Remove the oil motors in the power plant's steam turbine fire-resistant oil (EH) system and send them to the factory for overhaul. Install the flushing device at the location of the oil motor and connect it to the steam turbine EH system. Ensure that all interfaces are correctly connected and well sealed.

[0014] Connectivity: Connect the flushing medium to the device, set a reasonable flushing pressure and flow rate, and ensure a stable high-flow flushing process;

[0015] Circular flushing: Start the flushing process so that the flushing medium circulates throughout the EH system to effectively remove particulate matter and other impurities;

[0016] Real-time monitoring: Continuously monitor the particle size changes of the oil during the flushing process until the results of two consecutive sampling tests meet the standard requirements (particle size);

[0017] Complete flushing: When the oil particle size meets the standard, close the flushing process, remove the flushing method, and prepare for the subsequent oil motor reinstallation and valve switch activity test.

[0018] As a preferred solution of the method for flushing the fire-resistant oil (EH) system of a steam turbine in a power plant according to the present invention, the quick-cut valve, test assembly, shut-off assembly, etc. are converted into multi-way valves and connected to the steam turbine fire-resistant oil (EH) system, and only need to be rotated and switched during flushing.

[0019] As a preferred solution of the method for flushing the anti-fire oil (EH) system of a steam turbine in a power plant of the present invention, it is necessary to apply a variety of different connecting pipes, the connecting pipes including multi-way pipe 1, multi-way pipe 2, elbow pipe, connecting pipe 1 and connecting pipe 2, and each of the connecting pipes is provided with multiple specifications and models, and each of the connecting pipes is fixed to each other by a mounting portion.

[0020] As a preferred solution of the method for flushing the anti-fire oil (EH) system of a steam turbine in a power plant according to the present invention, the multi-way pipe 1 and the multi-way pipe 2 are provided with screw pipe ports and connecting ports of the mounting portion, adjacent multi-way pipes are connected with the blocking pipes through the connecting ports, and other pipes are connected to the screw pipe ports of the multi-way pipes through nuts.

[0021] As a preferred solution of the method for flushing the fire-resistant oil (EH) system of a steam turbine in a power plant according to the present invention, a power part, a valve and a sealing part are arranged in the spiral tube mouth. Under normal conditions, the power part located in the spiral tube mouth drives the valve to close and inflates and seals the sealing part located outside the valve in the spiral tube mouth.

[0022] As a preferred solution of the method for flushing the fire-resistant oil (EH) system of a steam turbine in a power plant according to the present invention, when any pipe is threadedly connected to the screw port, its nut squeezes the power part installed at the screw port, drives the valve to rotate and open, and inflates and seals the seal located at the end of the screw port.

[0023] As a preferred solution of the method for flushing the fire-resistant oil (EH) system of a steam turbine in a power plant of the present invention, the valve is configured as a disc, and two opposite rotating shafts are provided on its outer side wall, and the valve is rotatably installed in the screw pipe mouth via the rotating shafts.

[0024] As a preferred solution of the method for flushing the fire-resistant oil (EH) system of a steam turbine in a power plant according to the present invention, the sealing member includes a first rubber sealing ring installed at the end of the screw tube port, and a second rubber sealing ring installed in the screw tube port and located outside the valve. A connecting cavity is provided in the screw tube port, the first rubber sealing ring and the second rubber sealing ring are respectively connected to the two ends of the connecting cavity, and a piston is also provided in the connecting cavity.

[0025] As a preferred solution of the method for flushing the fire-resistant oil (EH) system of a power plant turbine of the present invention, the power member includes a gear mounted on any of the rotating shafts, and a rack meshing with the gear, and one end of the rack is connected to the piston through a flexible rod.

[0026] As a preferred solution of the method for flushing the fire-resistant oil (EH) system of a power plant turbine of the present invention, an extrusion plate is provided at one end of the rack, a limiting groove is opened on the side of the spiral tube mouth, and the rack and the extrusion plate slide along the limiting groove.

[0027] The beneficial effect of this invention's flushing method for the fire-resistant oil (EH) system of a power plant steam turbine is that the designed flushing device replaces the traditional oil motor flushing process. This device independently completes deep cleaning of the entire EH oil system before the oil motor is returned for flushing, successfully reducing the oil particle size to a high standard of 4 to 5. This innovation significantly reduces maintenance time. Previously, the valve switch activity test cycle required waiting for the oil motor to complete primary and secondary flushing before the valve switch activity test. With the new flushing device, the oil system flushing can be completed in advance, saving approximately one week of valuable maintenance time.

[0028] This application specially designs a screw nozzle structure with a built-in valve, so that when not connected to any pipeline, the valve always remains closed, ensuring the sealing performance and safety of the multi-way pipe equipped with the screw nozzle during long-term use in the EH system.

[0029] In summary, the new flushing scheme and structural design proposed in the present invention not only ensure that the EH system can be used in a long-term and stable manner in power plant turbines after flushing and modification, but also greatly improves the system's sealing, safety and ease of operation without affecting its normal operation, and significantly improves the flushing efficiency and effect of the entire EH system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0031] Figure 1 This is a schematic diagram of the anti-fire oil (EH) system of the power plant turbine.

[0032] Figure 2 This is a partially enlarged schematic diagram of the power plant's steam turbine fire-resistant oil (EH) system.

[0033] Figure 3 This is a schematic diagram of the connecting pipes used in the flushing method of the fire-resistant oil (EH) system of a power plant turbine.

[0034] Figure 4 This is a schematic diagram of the installation of a multi-way pipe.

[0035] Figure 5 for Figure 4 sectional view of .

[0036] Figure 6 for Figure 5 A magnified schematic diagram of the structure in the middle.

[0037] In the picture:

[0038] 100, connecting pipe; 101, multi-way pipe 1; 102, multi-way pipe 2; 103, elbow; 104, connecting pipe 1; 105, connecting pipe 2;

[0039] 200, mounting portion; 201, screw tube mouth; 201a, limiting groove; 202, connecting port; 203, blocking pipe; 204, nut; 205, power part; 205a, gear; 205b, rack; 205c, soft rod; 205d, extrusion plate; 205e, spring; 206, valve; 206a, disc; 206b, rotating shaft; 207, sealing element; 207a, first rubber sealing ring; 207b, second rubber sealing ring; 207c, connecting chamber; 207d, piston. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0042] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0043] Example 1

[0044] Reference Figure 1-Figure 3 , which is the first embodiment of the present invention, provides a method for flushing an anti-fire oil (EH) system of a steam turbine in a power plant, comprising:

[0045] Installation: Remove the oil motors in the power plant's steam turbine fire-resistant oil (EH) system and send them to the factory for maintenance. At the same time, install the flushing method at the oil motor position and connect it to the steam turbine (EH) system, and ensure that all interfaces are correctly connected and well sealed. Among them, the quick-cut valves, test components, and shut-off components are converted into multi-way valves and connected to the steam turbine fire-resistant oil (EH) system. They only need to be rotated and switched during flushing.

[0046] Connectivity: Connect the flushing medium to the device, set a reasonable flushing pressure and flow rate, and ensure a stable high-flow flushing process;

[0047] Circular flushing: Start the flushing process so that the flushing medium circulates throughout the (EH) system to effectively remove particulate matter and other impurities;

[0048] Real-time monitoring: Continuously monitor the particle size changes of the oil during the flushing process until the results of two consecutive sampling tests meet the particle size standards;

[0049] Complete flushing: When the oil particle size meets the standard, close the flushing process, remove the flushing method, and prepare for the subsequent oil motor reinstallation and valve switch activity test.

[0050] In this embodiment, during the installation phase, during the EH system maintenance process, first disassemble each hydraulic motor in the system ( Figure 1 and Figure 2 The high-pressure main steam valve, high-pressure regulating valve, medium-pressure combined steam valve and other internal oil motors) are sent to a professional factory for detailed inspection and repair. At the same time, a specially designed flushing device is installed at the original location of the oil motor, which is seamlessly connected to the steam turbine EH system. During the installation process, it is crucial to ensure that all interfaces are accurately connected and that the sealing performance of each connection point is firm and reliable to prevent oil leakage. It is worth noting that for important and complex parts of the system such as quick-cut valves, test components, and shut-off components ( Figure 1 and Figure 2 The designers employed a unique modification solution, connecting these components to the EH system via a multi-way valve. This allows for convenient switching of flushing procedures to specific components simply by rotating the multi-way valve's different ports.

[0051] Connectivity and setting of flushing media: When flushing the EH system of a power plant's steam turbine, first select a flushing medium that has been finely filtered or pre-treated, usually fire-resistant fuel or special flushing oil, to ensure that the medium itself does not contain impurities that may contaminate the system. This flushing medium is introduced into a special flushing device, and technicians will accurately set the pressure and flow rate of the flushing medium entering the system based on the design parameters and flushing requirements of the EH system. Excessive pressure may cause an impact on the system, while insufficient flow rate will not achieve an effective flushing effect. The ideal flushing condition is to maintain a large and stable flushing state while ensuring safety, which helps to push the flushing medium deep into all corners and tiny gaps of the EH system, fully and thoroughly cleaning each part.

[0052] Circulating Flushing and Impurity Removal: Once the flushing process is initiated, the flushing medium forms a closed loop within the EH system. Through repeated circulation, it gradually dissolves and removes various particulate matter, oxidation products, residues, and other impurities accumulated within the system. High-flow flushing effectively removes even tiny particles lurking in hard-to-reach areas such as pipe elbows, valve interiors, and motor cavities, ultimately restoring the EH oil's original purity, ensuring the system maintains excellent operating efficiency and extending equipment life.

[0053] Real-time Monitoring and Particle Size Control: Throughout the flushing process, an online particle size detector or other precision instrumentation is used to continuously monitor changes in the EH oil's particle size. This is because the effectiveness of the flushing process can be directly reflected by measuring the oil's particle size before and after flushing. Only when two consecutive sampling tests show that the EH oil's particle size has been reduced to a predetermined standard range, such as ≤5 (this is an assumed value; the actual standard depends on industry regulations), can it be confirmed that the flushing has achieved the intended goal and the oil's cleanliness level meets the requirements for continued use or further processing.

[0054] Flushing Completion and System Restoration: Once the EH oil's particle size meets acceptable standards, the flushing process is successfully completed. Flushing should be stopped immediately, and the flushing device should be carefully disassembled according to safety procedures. Next, maintenance personnel begin reinstalling the hydraulic motor and other related components, and conduct necessary function tests on the valve switches to verify that the EH system has resumed normal operation after flushing and maintenance, and that various performance indicators (such as response speed, sealing performance, and control accuracy) meet the process requirements and technical standards for power plant operation. This flushing and restoration process ensures that the EH electro-hydraulic control system can safely and efficiently serve the daily operation of the steam turbine generator set.

[0055] A carefully designed and engineered flushing device has replaced the existing hydraulic motor flushing mode. It independently completes a deep clean of the entire EH oil system before the motor returns for flushing, successfully reducing the oil particle size to a high standard of 4 to 5. This innovation significantly reduces maintenance time. Previously, the valve switch activity test cycle required waiting for the hydraulic motor to complete primary and secondary flushing. With the new flushing device, the oil system flushing can now be completed in advance, saving approximately one week of valuable maintenance time.

[0056] In practical application, the optimized flushing solution of the present invention was successfully validated during the overhaul of Unit 3 of the power plant. By utilizing high-flow flushing technology and efficient cleaning processes, the flushing effect was significantly improved, reducing the EH oil system flushing time from 5 to 7 days to achieve acceptable oil quality to just 3 days. Furthermore, two consecutive sampling tests showed that the particle size reached Grade 5, setting a record for the fastest time to complete an EH oil quality overhaul since the power plant's construction, achieving significant practical results.

[0057] Furthermore, the new flushing device eliminates the need for extensive disassembly and assembly of the EH oil system, ensuring zero leakage during unit startup and enabling smooth commissioning and testing. This series of achievements not only demonstrates a significant breakthrough in improving power plant operation and maintenance efficiency, but also heralds its broad application in the flushing of fire-resistant oil systems in power plants.

[0058] Further: See Figure 3 When flushing and retrofitting the fire-resistant fuel (EH) system of a power plant's steam turbine, a variety of connecting pipes 100 are required. These connecting pipes 100 include a multi-way pipe 101, a multi-way pipe 202, an elbow 103, a connecting pipe 1001, and a connecting pipe 1002. Each connecting pipe 100 is available in multiple specifications and types, and each connecting pipe 100 is secured to each other via a mounting portion 200. The multi-way pipe 101 and the multi-way pipe 202 are provided with screw ports 201 and communication ports 202 of the mounting portion 200. Adjacent multi-way pipes are connected to each other via the communication ports 202 and the plugging pipes 203. Other pipes are connected to the screw ports 201 of the multi-way pipes via nuts 204.

[0059] Specifically, during the flushing and retrofitting of the power plant's steam turbine EH system, a flexible and diverse connection solution was designed to accommodate the complex and sophisticated system layout. This solution utilizes a variety of different connecting pipes 100, including but not limited to multi-way pipe 1 101, multi-way pipe 2 102, elbow pipe 103, connecting pipe 1001, and connecting pipe 1002, in various shapes and sizes, to meet the connection requirements at various locations and angles within the EH system. Each type of connecting pipe 100 is available in multiple specifications to accommodate connection applications with varying diameters, lengths, and angles.

[0060] Multi-way pipe 101 and multi-way pipe 2 102 are key transition nodes. They feature a unique mounting structure: a screw port 201 and a connecting port 202. The screw port 201 is primarily used to securely connect to other pipes via threaded fasteners (such as nuts 204), ensuring a tight seal and stability. Connecting port 202, on the other hand, allows for communication with adjacent multi-way pipes or other components. A plugging pipe 203 may be used as a transitional component, enabling fluid transfer in different directions or branches through coordinated connection.

[0061] In short, the pipeline connection system in the entire flushing modification process builds a modular, flexibly interconnected network. Through the screw port 201 and the connecting port 202 on the multi-way pipe, as well as the matching accessories such as the plugging pipe 203 and the nut 204, the EH system flushing path can be freely configured and highly efficient flushing is achieved, ensuring that the flushing medium can reach every corner of the EH system unimpeded, thereby achieving comprehensive and effective cleaning of the fire-resistant oil in the system.

[0062] Example 2

[0063] Reference Figure 3-Figure 6 This is the second embodiment of the present invention. Unlike the previous embodiment, in order to ensure that the flushed and modified multi-way pipe equipped with a solenoid port 201 (especially for key parts such as the quick-cut valve, test assembly, and shut-off assembly, which need to be converted into a multi-way valve style so that it can be smoothly connected to the turbine fire-resistant oil (EH) system with a simple rotation during flushing) can be used in the EH system for a long time and stably without any adverse impact on the normal operation of the power plant turbine, the present application specifically designs that the valve 206 embedded in the solenoid port 201 always remains closed when not connected to any pipeline, thereby enhancing the overall sealing and safety.

[0064] Furthermore, when installing a pipe at any of the screw ports 201, tightening the nut 204 at the end of the pipe interacts with the screw port 201, automatically opening the valve 206. In other words, the interaction between the nut 204 and the screw port 201 not only secures the pipe connection but also controls the opening of the valve 206, ensuring the airtightness and safety of the EH system throughout all stages of installation and use.

[0065] Furthermore, considering the tiny gap that may appear during the docking process between the pipeline and the screw tube mouth 201, and the gap that may be generated by the installation method of the valve 206 inside the screw tube mouth 201, both of these may pose a risk of liquid leakage inside the EH system. For this reason, the present invention has designed a matching seal 207. When the operation of connecting the pipeline to the screw tube mouth 201 is carried out, when the power part 205 is started and prompts the valve 206 to open, this sealing structure will also be activated. Its function is to effectively fill and seal any gap that may exist between the docking surface of the pipeline and the screw tube mouth 201, and at the same time, the gap generated between the valve 206 and the inner wall of the screw tube mouth 201 is also tightly sealed.

[0066] In this way, both the connection point between the pipeline and the screw port 201 and the rotating part of the valve 206 can be tightly sealed, thereby fundamentally eliminating any form of liquid leakage problem and effectively ensuring the overall sealing and operating efficiency of the EH system.

[0067] Specifically, a power element 205, a valve 206, and a sealing element 207 are provided within the solenoid port 201. Under normal conditions, the power element 205 within the solenoid port 201 drives the valve 206 to close and inflates and seals the sealing element 207 located outside the valve 206 within the solenoid port 201. When any pipe is threadedly connected to the solenoid port 201, its nut 204 compresses the power element 205 installed at the solenoid port 201, driving the valve 206 to rotate open and inflating and sealing the sealing element 207 at the end of the solenoid port 201.

[0068] Under normal circumstances, the power element 205 inside the screw nozzle 201 will drive the valve 206 to a closed state. At the same time, the power element 205 inflates the sealing element 207 on the outside of the valve 206 through a soft rod 205c or other means, causing it to expand and deform, thereby achieving effective sealing of the screw nozzle 201 and preventing EH oil or other flushing media from flowing out when the pipe 100 is not connected. When any pipe needs to be threadedly connected to the screw nozzle 201, the nut 204 at the end of the pipe will produce a squeezing effect on the power element 205 pre-installed at the screw nozzle 201 through physical contact during the process of being screwed into the screw nozzle 201. This squeezing action will trigger the working mechanism of the power element 205, thereby driving the valve 206 from a closed state to an open state. At the same time, the operation of opening the valve 206 will also change the inflation position of the seal 207. The seal 207 on the outside of the original valve 206 will no longer be inflated, but the other seal 207 at the docking port of the screw tube 201 and the pipeline will be inflated to expand it and form a new sealing layer to ensure that the newly connected pipeline and the screw tube 201 are tight and leak-free.

[0069] This design cleverly utilizes the screwing-in and screwing-out action of the nut 204 to automatically realize the opening and closing of the valve 206 and the switching of the inflation and deflation of the seal 207, ensuring both the rapid connection and disconnection during the flushing and modification of the EH system and the sealing performance in the connected state, thus greatly improving the stability and reliability of the system.

[0070] The valve 206 is configured as a disc 206a, with two opposing rotating shafts 206b provided on its outer wall. The valve 206 is rotatably mounted within the solenoid orifice 201 via the rotating shafts 206b. The sealing element 207 comprises a first rubber sealing ring 207a mounted at the end of the solenoid orifice 201, and a second rubber sealing ring 207b mounted within the solenoid orifice 201, located outside the valve 206. A connecting cavity 207c is provided within the solenoid orifice 201, with the first and second rubber sealing rings 207a, 207b respectively connected at opposite ends of the connecting cavity 207c. A piston 207d is also provided within the connecting cavity 207c. The power element 205 comprises a gear 205a mounted on either rotating shaft 206b, and a rack 205b meshing with the gear 205a. One end of the rack 205b is connected to the piston 207d via a flexible rod 205c. An extrusion plate 205d is provided at one end of the rack 205b, and a limiting groove 201a is provided on the side of the screw tube mouth 201, and the rack 205b and the extrusion plate 205d slide along the limiting groove 201a.

[0071] Specifically, when a certain screw pipe port 201 needs to be connected to a pipe, the nut 204 of the pipe is screwed onto the outer wall of the screw pipe port 201 and pushes the extrusion plate 205d to move inward along the limiting groove 201a. The extrusion plate 205d drives the rack 205b to move, and the rack 205b drives the gear 205a engaged therewith to rotate. The gear 205a drives the rotating shaft 206b to rotate, and the rotating shaft 206b drives the disc 206a to flip, thereby opening the valve 206. At the same time, the rack 205b The movement of the soft rod 205c pulls the piston 207d to move in the connecting chamber 207c, and the piston 207d moves from the second rubber sealing ring 207b side to the first rubber sealing ring 207a side in the connecting chamber 207c, thereby deflating the second rubber sealing ring 207b and inflating the first rubber sealing ring 207a. Since the first rubber sealing ring 207a is located at the end of the screw tube port 201, the docking gap between the two installed pipes is blocked, thereby achieving a perfect sealing effect.

[0072] On the contrary, when the pipe is disassembled, the departure of the nut 204 causes the rack 205b and the extrusion plate 205d to move outward along the limit groove 201a under the action of the spring 205e. The outward movement of the rack 205b drives the gear 205a to reverse, thereby driving the disc 206a to reverse through the rotating shaft 206b and sealing the screw tube mouth 201. At the same time, the outward movement of the rack 205b also pushes the piston 207d to move in the connecting chamber 207c through the soft rod 205c, and moves the piston 207d from the first rubber sealing ring 207a side of the connecting chamber 207c to the second rubber sealing ring 207b side, thereby achieving the degassing of the first rubber sealing ring 207a and the inflation of the second rubber sealing ring 207b. Since the second rubber sealing ring 207b is located outside the valve 206, the gap between the valve 206 and the inner wall of the screw tube mouth 201 is blocked, ensuring that no leakage occurs during the disassembly process.

[0073] It is important to note that the construction and arrangement of the present application, as illustrated in various exemplary embodiments, are illustrative only. Although only a few embodiments are described in detail in this disclosure, those reading this disclosure will readily appreciate that numerous modifications are possible (e.g., variations in the size, dimensions, structure, shape, and proportions of various components, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, components shown as integrally formed may be constructed from multiple parts or components, the positions of components may be inverted or otherwise altered, and the nature, number, or position of discrete components may be modified or changed. All such modifications are therefore intended to be encompassed within the scope of this invention. The order or sequence of any process or method steps may be altered or resequenced according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover structures described herein that perform the recited function, and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of this invention. Therefore, the invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0074] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment may not be described (i.e., those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention).

[0075] It will be appreciated that in the development of any actual embodiment, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will, for those of ordinary skill having the benefit of this disclosure, be a routine undertaking of design, fabrication, and production without undue experimentation.

[0076] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for flushing an EH system of a steam turbine in a power plant, characterized by: include, Installation: Remove the oil motors in the steam turbine EH system of the power plant and send them to the factory for overhaul. At the same time, install the flushing device at the location of the oil motor and connect it to the steam turbine EH system. Ensure that all interfaces are correctly connected and well sealed. Connectivity: Connect the flushing medium to the device, set a reasonable flushing pressure and flow rate, and ensure a stable high-flow flushing process; Circular flushing: Start the flushing process so that the flushing medium circulates throughout the EH system to effectively remove particulate matter and other impurities; Real-time monitoring: Continuously monitor the particle size changes of the oil during the flushing process until the results of two consecutive sampling tests meet the standard requirements; Complete flushing: When the oil particle size meets the standard, close the flushing process, remove the flushing method, and prepare for the subsequent oil motor reinstallation and valve switch activity test; It is necessary to apply to a variety of different connecting pipes, including multi-way pipe 1, multi-way pipe 2, elbow pipe, connecting pipe 1 and connecting pipe 2, and each of the connecting pipes is provided with multiple specifications and models, and each of the connecting pipes is fixed to each other through a mounting portion; The multi-way pipe 1 and the multi-way pipe 2 are provided with the screw pipe opening and the communication opening of the installation part, the adjacent multi-way pipes are connected with the blocking pipes through the communication opening, and the other pipes are connected with the screw pipe opening of the multi-way pipe through nuts; A power member, a valve and a sealing member are provided in the solenoid port. Under normal conditions, the power member in the solenoid port drives the valve to close and inflates and seals the sealing member located outside the valve in the solenoid port. The valve is configured as a disc, and two opposite rotating shafts are provided on its outer side wall, and the valve is rotatably mounted in the screw tube port via the rotating shafts; The sealing member includes a first rubber sealing ring installed at the end of the screw tube port, and a second rubber sealing ring installed in the screw tube port and located outside the valve. A communication cavity is provided in the screw tube port, and the first rubber sealing ring and the second rubber sealing ring are respectively connected to the two ends of the communication cavity. A piston is also provided in the communication cavity. The power member includes a gear mounted on any of the rotating shafts, and a rack meshing with the gear, one end of the rack being connected to the piston via a flexible rod; An extrusion plate is provided at one end of the rack, and a limiting groove is provided on the side of the screw tube mouth. The rack and the extrusion plate slide along the limiting groove, and a spring is provided in the limiting groove to push the rack outward.

2. The method for flushing an EH system of a steam turbine in a power plant according to claim 1, wherein: Among them, the quick-cut valve, test assembly, and shut-off assembly are transformed into multi-way valves and connected to the turbine EH system. They only need to be rotated and switched during flushing.

3. The method for flushing an EH system of a steam turbine in a power plant according to claim 2, wherein: When any pipe is screwed to the screw pipe port, its nut squeezes the power component installed at the screw pipe port, drives the valve to rotate and open, and inflates and seals the sealing component at the end of the screw pipe port.

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