A method for optimizing combined motion of anti-sticking rotation of a main regulating valve of a steam turbine

Abstract

The application discloses a kind of turbine main regulating valve anti jamming rotation combination movement optimization design methods, comprising: constructing the three-dimensional geometric model of turbine main regulating valve, the three-dimensional geometric model is mesh discrete;Set boundary condition, utilize the three-dimensional geometric model to carry out dynamic simulation analysis and valve activity test evaluation, to determine the best combination mode and combination parameter of the rotation movement and axial movement of valve stem and valve disc under different factor conditions;According to the best combination mode and combination parameter of the rotation movement and axial movement of valve stem and valve disc under different factor conditions, control turbine main regulating valve, which can effectively solve the problem of valve stem and valve disc jam caused by scale particles.

Description

Technical Field

[0001] This invention belongs to the field of optimization design technology and relates to an optimization design method for the anti-jamming rotational combined motion of the main control valve of a steam turbine. Background Technology

[0002] A steam turbine is a rotary prime mover that uses steam as its working fluid to convert thermal energy into mechanical energy. In modern conventional thermal power plants, nuclear power plants, and geothermal power plants that use fossil fuels, steam turbines drive generators to produce electricity; therefore, the combination of a steam turbine and a generator is called a steam turbine generator set. Before entering the steam turbine, the main steam must pass through the main control valve, namely the high-pressure main steam valve and the high-pressure regulating valve, to regulate the power of the steam turbine generator set and to quickly cut off the steam supply in case of unit malfunction, ensuring the safe operation of the steam turbine and generator. For high-parameter steam turbines with reheat, the main control valve also includes the intermediate-pressure main steam valve and the intermediate-pressure regulating valve for controlling the steam intake of the intermediate-pressure cylinder. Currently, approximately 80% of the world's electricity is generated by steam turbine generator sets; therefore, improving the reliability of the main control valve is of great significance for stabilizing the power supply.

[0003] For the main control valve, the valve stem and valve disc are moving parts, capable of free movement within the valve stem sleeve and valve disc sleeve, which are fixed to the valve body. The clearance between the valve stem and valve stem sleeve, and between the valve disc and valve disc sleeve, is very small. This clearance primarily serves to ensure the free movement of the valve disc while providing good constraint and guidance, reducing vibration under high-speed steam flow disturbances when the valve is open, and ensuring accurate fit between the valve disc and valve seat sealing surfaces when the valve is closed, thus guaranteeing a tight seal. Due to the extremely harsh working environment of the main control valve, oxide films easily form on the surfaces of the valve stem sleeve, valve disc, and valve sleeve. These oxide films detach under the influence of steam flow force, mechanical friction, vibration, and thermal stress, producing oxide scale particles. Furthermore, oxide scale from upstream steam pipes can be carried into the valve stem and valve disc clearances by the steam. Conventionally designed valve stem and valve disc clearances are very small, and oxide scale particles often cause valve disc jamming, leading to turbine overspeed and severely impacting the safe operation of the turbine. Therefore, the "Technical Supervision Guidelines for Steam Turbines in Thermal Power Plants" (DL / T 1055-2021) stipulates that a main steam valve and regulating valve operation / loosening test should be conducted daily, with the operating valves operating at 10% to 20% of their stroke. For steam turbines that can be supplied with steam from one side, a full stroke operation test of the main steam valve and regulating valve should be conducted monthly under low load and low steam pressure, or during start-up and shutdown. However, although many thermal power plants have conducted valve operation tests according to the guidelines, it is difficult to effectively deal with stuck valves, and safety hazards have not been eliminated. Several recent safety accidents in China are related to this, mainly because there are no effective methods to release the stuck state and remove oxide scale from the gaps. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an optimized design method for the anti-jamming rotary combination motion of the main control valve of a steam turbine. This method can effectively solve the problem of valve stem and valve disc jamming caused by oxide scale particles.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In one aspect, this invention provides a method for optimizing the rotational motion of a steam turbine main control valve to prevent jamming, comprising:

[0007] A three-dimensional geometric model of the main control valve of the steam turbine is constructed, and the three-dimensional geometric model is discretized by meshing;

[0008] Boundary conditions are set, and the three-dimensional geometric model is used to perform dynamic simulation analysis and valve activity test evaluation to determine the optimal combination of rotational and axial motion of valve stem and valve disc under different conditions.

[0009] Based on the optimal combination and parameters of the rotational and axial motions of the valve stem and valve disc under the aforementioned different factors, the main control valve of the steam turbine is controlled.

[0010] The further improvement of the turbine main control valve anti-jamming rotational motion optimization design method described in this invention lies in:

[0011] The three-dimensional geometric model includes the internal structure of the valve cavity, valve disc, valve sleeve, valve stem, and valve stem sleeve.

[0012] The combination method and combination parameters include the rotation angle of the valve disc and valve stem, the rotation speed of the valve disc and valve stem, and the axial displacement of the valve stem.

[0013] The different factors include the clearance size between the valve disc and the valve sleeve, the clearance size between the valve stem and the valve stem sleeve, the oxidation characteristics of the material, the magnitude of the lifting force, and the valve pneumatic parameters.

[0014] The specific process of performing dynamic simulation analysis using the three-dimensional geometric model is as follows:

[0015] Through simulation analysis, the motion characteristics of the main control valve of the steam turbine under different operating conditions are simulated, and the relative motion parameters of the valve disc and valve sleeve, and the valve stem and valve stem sleeve are determined, as well as the influence of the particle movement and force within the gap between the valve disc and valve sleeve and the gap between the valve stem and valve stem sleeve.

[0016] Boundary conditions are set based on the actual operating parameters of the turbine's main control valve, including pressure, temperature, and flow rate.

[0017] Also includes:

[0018] A drive mechanism is provided, which includes a drive motor, a first gear, and a second gear. The first gear is sleeved on the output shaft of the drive motor, and the second gear is sleeved on the valve stem. The first gear and the second gear mesh with each other.

[0019] In one aspect, the present invention provides an optimized design system for the anti-jamming rotational motion combination of a steam turbine main control valve, comprising:

[0020] A construction module is used to construct a three-dimensional geometric model of the main control valve of the steam turbine, and to perform mesh discretization on the three-dimensional geometric model;

[0021] The evaluation module is used to set boundary conditions and use the three-dimensional geometric model to perform dynamic simulation analysis and valve activity test evaluation to determine the optimal combination of rotational and axial motion of valve stem and valve disc under different conditions.

[0022] The control module is used to control the main control valve of the steam turbine according to the optimal combination and combination parameters of the rotational and axial motion of the valve stem and valve disc under the different factors.

[0023] The present invention has the following beneficial effects:

[0024] The turbine main control valve anti-jamming rotational motion optimization design method of the present invention, in specific operation, increases the rotational motion of the valve stem and valve disc, so that the particles are more evenly distributed in the gaps between the valve disc and valve sleeve, and between the valve stem and valve stem sleeve, which helps to reduce jamming and particle retention. At the same time, simulation optimization is used to screen out the optimal combination of rotational motion and axial motion of valve stem and valve disc under different conditions, and further solve the problem of valve stem and valve disc jamming caused by oxide scale particles. Attached Figure Description

[0025] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 A schematic diagram illustrating the situation of particulate matter getting stuck in a traditional valve disc and valve sleeve;

[0027] Figure 2 This is a schematic diagram illustrating the situation where particulate matter gets stuck between the valve stem and the valve stem sleeve in a traditional valve.

[0028] Figure 3 This is a schematic diagram of the particle distribution in the optimized valve disc and valve disc sleeve according to the present invention;

[0029] Figure 4 This is a schematic diagram of the particle distribution in the optimized valve stem and valve stem sleeve according to the present invention;

[0030] Figure 5 This is a diagram showing the connection relationship between the drive motor, the first gear, and the second gear in this invention.

[0031] Among them, 1 is the valve disc, 2 is the valve sleeve, 3 is the valve stem, 4 is the valve stem sleeve, 5 is the first gear, 6 is the drive motor, and 7 is the second gear. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] The present invention will now be described in further detail with reference to the accompanying drawings:

[0035] Example 1

[0036] The turbine main control valve anti-jamming rotational motion optimization design method of the present invention includes the following steps:

[0037] Based on the gap dimensions between valve disc 1 and valve sleeve 2, the gap dimensions between valve stem 3 and valve stem sleeve 4, material oxidation characteristics, lifting force, and valve pneumatic parameters, the optimal combination and parameters for the rotational and axial movements of valve stem 3 and valve disc 1 are determined. These combinations and parameters include the rotation angles of valve disc 1 and valve stem 3, the rotational speeds of valve disc 1 and valve stem 3, and the axial displacement of valve stem 3. This ensures uniform distribution of particles trapped in the gaps between valve disc 1 and valve sleeve 2, and between valve stem 3 and valve stem sleeve 4, reducing jamming and particle retention. This, in turn, reduces vibration of valve stem 3 and valve disc 1, solving the problems of jamming and particle retention in valve stem 3 and valve disc 1, and has broad engineering application prospects.

[0038] Specifically, the following steps are included:

[0039] 1) Establish a three-dimensional geometric model and discretize the mesh;

[0040] A three-dimensional geometric model of the main control valve of the steam turbine is established. The three-dimensional geometric model includes the internal structure of the valve cavity, valve disc 1, valve sleeve 2, valve stem 3 and valve stem sleeve 4. The three-dimensional geometric model is then discretized into a mesh, and the flow field region and the structural region in the three-dimensional geometric model are subdivided into meshes respectively.

[0041] 2) Set boundary conditions and perform dynamic simulation analysis;

[0042] Based on the actual operating parameters of the turbine main control valve, boundary conditions are set. The actual operating parameters include pressure, temperature and flow rate. A three-dimensional dynamic simulation analysis is performed on the three-dimensional geometric model of the turbine main control valve to simulate the motion characteristics of the turbine main control valve under different operating conditions. The motion characteristics include rotational motion and axial motion. Preferably, the three-dimensional dynamic simulation analysis can be performed using commercial software such as ANSYS and ABAQUS.

[0043] Through simulation, the relative motion parameters of valve disc 1 and valve sleeve 2, and valve stem 3 and valve stem sleeve 4 under different operating conditions of the main control valve of the steam turbine were determined, and the influence of these parameters on the movement and force of particles in the gap between valve disc 1 and valve sleeve 2 and the gap between valve stem 3 and valve stem sleeve 4 was determined.

[0044] 3) Evaluation combined with valve operation tests;

[0045] The simulation analysis results of step 2) are compared and evaluated with the actual activity test data of the turbine main control valve to verify the accuracy of the simulation analysis.

[0046] 4) Based on the simulation results, with the goal of uniform distribution of particles in the gaps between valve disc 1 and valve sleeve 2, and between valve stem 3 and valve stem sleeve 4, determine the optimal combination of rotational and axial motion of valve stem 3 and valve disc 1 under different conditions, namely, the rotation angle of valve disc 1 and valve stem 3, the rotation speed of valve disc 1 and valve stem 3, and the axial displacement of valve stem 3.

[0047] 5) Control the turbine main control valve according to the optimal combination of rotational and axial motion of valve stem 3 and valve disc 1 under different factor conditions, so that the particles stuck in the gap between valve disc 1 and valve sleeve 2, and between valve stem 3 and valve stem sleeve 4 are more evenly distributed, so as to reduce jamming and particle retention.

[0048] refer to Figure 3 , Figure 4 This invention solves the problems of valve stem 3, valve disc 1 jamming and particulate matter retention.

[0049] Typical simulation analysis results of the main control valve of the steam engine show that when multiple layers of 0.1mm thick oxide scale form an interlock and cause the valve stem 3 to jam, the particulate matter interlock can be effectively released and the particulate matter can be dispersed when the rotational linear velocity reaches 3-5 times the axial linear velocity opposite to the interlocking direction.

[0050] The main control valve of the steam engine involved in this invention includes core components such as valve stem 3, valve stem sleeve 4, valve disc 1 and valve disc 1 sleeve. The newly added rotation of valve stem 3 and valve disc 1 drives the first gear 5 through an additionally configured drive mechanism, which in turn drives the second gear 7 on valve stem 3, thus affecting the performance and operating characteristics of the valve.

[0051] In this embodiment, the three-dimensional dynamic simulation analysis is as follows: by simulating the motion and flow field of the internal structure of the valve, the influence of the relative motion parameters of valve disc 1 and valve sleeve 2, and valve stem 3 and valve stem sleeve 4 on the motion and force of particles in the gap is determined, so as to screen out the optimal combination method and combination parameters.

[0052] In this embodiment, the rotational combined motion is the coupling of the rotational motion between the valve disc 1 and the valve stem 3 and the axial motion of the valve lift, wherein the rotational motion is the controllable rotation of the valve disc 1 around the axial centerline of the valve stem 3.

[0053] During actual valve testing, this invention introduces a rotational combination motion. By increasing the rotational motion, particles are more evenly distributed in the gaps between valve disc 1 and valve sleeve 2, and between valve stem 3 and valve stem sleeve 4, which helps to reduce jamming and particle retention.

[0054] To achieve the combined rotary motion of the valve, an external drive mechanism is used, such as... Figure 5 As shown, the drive motor 6 can be a servo motor or a stepper motor, and combined with a gear structure or a worm gear structure to drive the rotational movement of the valve stem 3 and the valve disc 1, so as to ensure the controllability and stability of the valve movement.

[0055] Example 2

[0056] The turbine main control valve anti-jamming rotational motion optimization design system of the present invention includes:

[0057] A construction module is used to construct a three-dimensional geometric model of the main control valve of the steam turbine, and to perform mesh discretization on the three-dimensional geometric model;

[0058] The evaluation module is used to set boundary conditions and perform dynamic simulation analysis and valve activity test evaluation using the three-dimensional geometric model to determine the optimal combination of rotational and axial motion of valve stem 3 and valve disc 1 under different conditions.

[0059] The control module is used to control the main control valve of the steam turbine according to the optimal combination and combination parameters of the rotational and axial motion of the valve stem 3 and the valve disc 1 under the different factors.

[0060] Example 3

[0061] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the optimized design method for the anti-jamming rotational combination motion of a steam turbine main control valve. The memory may include main memory, such as high-speed random access memory, or it may also include non-volatile memory, such as at least one disk storage device. The processor, network interface, and memory are interconnected via an internal bus, which may be an industry-standard architecture bus, a peripheral component interconnection standard bus, or an extended industry-standard architecture bus. The bus can be categorized as an address bus, data bus, or control bus. The memory stores the program; specifically, the program may include program code, which includes computer operation instructions. The memory may include main memory and non-volatile memory, and it provides instructions and data to the processor.

[0062] Example 4

[0063] A computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the optimized design method for the anti-jamming rotational combination motion of the main control valve of a steam turbine. Specifically, the computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. The volatile memory may include random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include read-only memory (ROM), hard disk, flash memory, optical disk, magnetic disk, etc.

[0064] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0066] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0067] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for optimizing the rotational motion of a steam turbine main control valve to prevent jamming, characterized in that, include: A three-dimensional geometric model of the main control valve of the steam turbine is constructed, and the three-dimensional geometric model is discretized by meshing; Set boundary conditions, use the three-dimensional geometric model to perform dynamic simulation analysis and valve activity test evaluation, so as to determine the best combination of rotational motion and axial motion of valve stem (3) and valve disc (1) under different factors; Based on the optimal combination of the rotational and axial motions of the valve stem (3) and the valve disc (1) under the different conditions, the main control valve of the steam turbine is controlled. The combination method and combination parameters include the rotation angle of the valve disc (1) and the valve stem (3), the rotation speed of the valve disc (1) and the valve stem (3), and the axial displacement of the valve stem (3); The different factors include the gap size between the valve disc (1) and the valve sleeve (2), the gap size between the valve stem (3) and the valve stem sleeve (4), the oxidation characteristics of the material, the magnitude of the lifting force, and the valve pneumatic parameters; The specific process of performing dynamic simulation analysis using the three-dimensional geometric model is as follows: Through simulation analysis, the motion characteristics of the main control valve of the steam turbine under different operating conditions are simulated, and the relative motion parameters of the valve disc (1) and valve sleeve (2), valve stem (3) and valve stem sleeve (4) are determined, as well as the influence of the particle motion and force in the gap between the valve disc (1) and valve sleeve (2) and the gap between the valve stem (3) and valve stem sleeve (4).

2. The turbine main control valve anti-jamming rotational motion optimization design method according to claim 1, characterized in that, The three-dimensional geometric model includes the internal structure of the valve cavity, valve disc (1), valve sleeve (2), valve stem (3), and valve stem sleeve (4).

3. The turbine main control valve anti-jamming rotational motion optimization design method according to claim 1, characterized in that, Boundary conditions are set based on the actual operating parameters of the turbine's main control valve.

4. The turbine main control valve anti-jamming rotational motion optimization design method according to claim 3, characterized in that, The actual operating parameters include pressure, temperature, and flow rate.

5. The turbine main control valve anti-jamming rotational motion optimization design method according to claim 1, characterized in that, Also includes: A drive mechanism is provided, which includes a drive motor (6), a first gear (5) and a second gear (7). The first gear (5) is sleeved on the output shaft of the drive motor (6), and the second gear (7) is sleeved on the valve stem (3). The first gear (5) and the second gear (7) mesh with each other.

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