A solid particle erosion test platform for steam turbine blades

Abstract

The present invention relates to the field of nuclear power plant steam turbines, and in particular to a solid particle erosion experimental platform for steam turbine blades. The experimental platform comprises: an air compressor connected to an air storage tank; a solenoid valve connected to the air storage tank, and a synchronizer controlling the opening and closing of the solenoid valve; a launch tube connected to the solenoid valve at one end and a simulated cylinder at the other end; a particle generator connected to the launch tube; an exhaust pipe and a particle velocity measuring tube are sequentially installed at the connection end of the launch tube and the simulated cylinder; a blade is placed in the simulated cylinder, and the blade is driven to rotate by a motor; a phase detector is connected to the motor, and the phase detector is connected to the solenoid valve via a synchronizer to control the emitted particles to hit the blades. The present invention truly restores the operating conditions of the steam turbine, simulates the collision process of solid particles of different shapes and particle sizes with the blades, and can more intuitively and clearly illustrate the erosion and damage mechanism of solid particle foreign matter.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power plant steam turbines, and in particular to a solid particle erosion test platform for steam turbine blades. Background Art

[0002] Nuclear power generation primarily relies on high-temperature, high-pressure steam generated by steam generators to propel the turbine generator. Steam travels through long pipelines from the generator to the turbine. Corrosion, oxidation, and spalling of the metal linings within these pipelines produce a large number of oxidized microparticles, ranging in diameter from a few microns to several millimeters. These metal microparticles are carried by the airflow into the turbine's flow path. Solid particles, present in a low concentration within the airflow, can be considered discrete solid particles with a finite mass and inertia. Initially, these particles move along the turbine's axial direction. However, the curved flow path of the stator blades, coupled with the circumferential rotation of the impeller and rotor blades, creates high relative velocities between the particles and the turbine blades. This relative motion between the particles and the turbine blades causes varying degrees of wear on the blades and other turbine components. This abrasive action can lead to material loss and loss on the component surfaces. In a multi-stage steam turbine, solid particles may cause different forms of impact wear and rebound between different stationary and moving blades. Impact wear can cause serious damage to the blades, forming pits of varying degrees on the blade surface, significantly increasing blade pressure loss and other changes in aerodynamic performance. This is different from newly processed blades. The airflow cannot flow smoothly on the blade surface after solid particle erosion, which causes the dissipation of airflow energy and ultimately reduces the efficiency of the steam turbine. More importantly, because solid particle erosion changes the appearance of the blade, especially for some solid particles with larger particle sizes, the impact on the blade can cause material loss in some parts of the blade, thereby changing the mechanical properties of the blade. Under the centrifugal force of the high speed of the turbine, these blades with missing material may break because the mechanical properties do not meet the requirements of extreme working conditions, seriously threatening the safe operation of the steam turbine.

[0003] To investigate the damage mechanism of solid particle impact, many researchers at home and abroad have attempted to use finite element-based numerical methods to address the impact of solid particles on materials. While numerical methods offer the flexibility and convenience of simulating impact behavior tailored to various factors (such as material type, particle velocity, size, shape, and impact angle), their results are limited to capturing the shape of plastic pits and residual stress distribution on the blade surface, and they still cannot accurately explain the damage mechanism of solid particle impact. The exploration of fundamental theoretical models for solid particle erosion wear began in the late 1980s. Since the microcutting model, the first theoretical model for erosion, was proposed by Finnie I in 1958, researchers at home and abroad have devoted themselves to the study of erosion theory, summarizing and proposing numerous theoretical models in an effort to provide the most appropriate explanation for the erosion mechanism. Meng has conducted extensive research in this area, including summarizing 28 previously proposed erosion models. While different models provide varying interpretations of material erosion behavior, to date, no single erosion model adequately and fully explains the underlying mechanisms of the erosion process. Therefore, a suitable physical experimental platform is needed to explain the erosion and destruction behavior of solid particles. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a solid particle erosion experimental platform for turbine blades, which can more realistically restore the operating conditions of the turbine, simulate the collision process between solid particles of different shapes and particle sizes and the blades, and more intuitively and clearly illustrate the erosion and damage mechanism of solid particle foreign matter.

[0005] The present invention provides a steam turbine blade solid particle erosion experimental platform, comprising: a motor, a phase detector, a simulated cylinder, blades, a synchronizer, a particle generator, an air compressor, an air storage tank, a solenoid valve, and a launch tube;

[0006] The air compressor is connected to the air storage tank;

[0007] The solenoid valve is connected to the gas tank, and the synchronizer controls the opening and closing of the solenoid valve;

[0008] One end of the launch tube is connected to the solenoid valve, and the other end is connected to the simulated cylinder;

[0009] The launch tube is connected to the particle generator;

[0010] The connection ends of the launch tube and the simulation cylinder are equipped with an exhaust pipe and a particle velocity measuring tube in sequence;

[0011] The blades are placed in a simulated cylinder and driven by a motor to rotate;

[0012] The phase detector is connected to the motor to measure the phase of the motor. The phase detector is connected to the electromagnetic valve via the synchronizer to control the emitted particles to hit the blades.

[0013] Preferably, the launch tube is also equipped with a horizontal adjustment support and a vertical lifting support.

[0014] It is used to adjust the spatial position of the launch tube to adjust the angle of the particles entering the simulation cylinder.

[0015] Preferably, there are two blades, and the two blades are spaced 180 degrees apart.

[0016] Preferably, a safety relief valve and a pressure sensor are installed on the gas storage tank.

[0017] Preferably, the air compressor is connected to the air storage tank through a check valve.

[0018] Preferably, the transmitting tube and the solenoid valve are connected via a connecting hose.

[0019] Preferably, the blades are connected to the main shaft of the motor, and the motor drives the blades to rotate at a high speed of 1500 rpm to 1800 rpm.

[0020] Preferably, one end of the launch tube close to the solenoid valve is connected to a particle generator.

[0021] Preferably, the particle generator provides solid particles of different sizes, shapes and properties.

[0022] Preferably, the launch tube is movable, and the horizontal adjustment support and the vertical lifting support are adjusted to enable the solid particles to enter the cylinder and collide with the blades at different spatial angles.

[0023] Compared with the prior art, the steam turbine blade solid particle erosion test platform of the present invention has the following beneficial effects:

[0024] (1) Ability to realistically reproduce the collision environment between solid particles and blades. By introducing high-temperature, high-pressure steam into a simulated cylinder and using a motor to drive the blades to rotate, the blades' operating environment is reproduced. Compressed air is used to accelerate the movement of solid particles, ensuring that the relative speed of the solid particles and blades is consistent.

[0025] (2) It can comprehensively analyze the impact damage behavior of multiple factors. Solid particles of various sizes and shapes are collided with the blade to quantitatively analyze the effects of particle size, shape, and velocity on the impact process. The angle at which the solid particles enter the cylinder is adjusted to quantitatively analyze the effect of the angle on the impact process.

[0026] (3) It can analyze the multiple impact behaviors at the same point. By detecting the motor phase and synchronizing it with the launch device, it is possible to conduct physical experiments on the multiple impact behaviors at the same point on the blade and analyze the mechanism of damage caused by multiple impact behaviors to the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram showing the structure of a steam turbine blade solid particle erosion test platform;

[0028] In the figure,

[0029] 1. Motor; 2. Phase detector; 3. Simulated cylinder; 4. Blades; 5. Synchronizer; 6. Particle generator; 7. Connecting hose; 8. Safety air release valve; 9. Pressure sensor; 10. Air compressor; 11. Check valve; 12. Air tank; 13. Solenoid valve; 14. Launch tube; 15. Horizontal adjustment support; 16. Vertical lifting support; 17. Exhaust pipe; 18. Particle velocity measuring tube. DETAILED DESCRIPTION

[0030] In order to further understand the present invention, embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the present invention.

[0031] The embodiment of the present invention discloses a solid particle erosion experimental platform for steam turbine blades, comprising: a motor 1, a phase detector 2, a simulated cylinder 3, blades 4, a synchronizer 5, a particle generator 6, an air compressor 10, an air storage tank 12, a solenoid valve 13, and a launch tube 14;

[0032] The air compressor 10 is connected to the air storage tank 12 through a check valve 11. The high-pressure air generated by the air compressor enters the air storage tank. The function of the check valve is to prevent the gas from flowing back.

[0033] The solenoid valve 13 is connected to the gas storage tank 12, and the synchronizer 5 controls the opening and closing of the solenoid valve.

[0034] The gas tank is equipped with a safety release valve 8 and a pressure sensor 9. The safety release valve 8 is to ensure the safety of the gas tank and prevent damage due to excessive pressure in the tank; and the pressure sensor 9 is used to measure the pressure in the tank.

[0035] One end of the launch tube 14 is connected to the solenoid valve 13, and the other end is connected to the simulated cylinder 3;

[0036] The transmitting tube 14 is connected to the electromagnetic valve 13 by a connecting hose 7. Since the transmitting tube is movable, the connecting hose is designed.

[0037] The other end of the launch tube 14 is connected to the simulated air cylinder 3. The end of the launch tube 14, near the solenoid valve 13, is connected to the particle generator 6. High-pressure compressed air from the air tank passes through the solenoid valve and a flexible hose, carrying particles through the launch tube and into the simulated air cylinder. The launch tube is equipped with an exhaust pipe 17 and a particle velocity measuring tube 18. The compressed air is released into the atmosphere through the exhaust pipe 17, while the particles, after their velocity is measured by the velocity measuring tube, enter the simulated air cylinder.

[0038] The particle generator provides solid particles of different sizes, shapes and properties.

[0039] The launch tube 14 is also provided with a horizontal adjustment support 15 and a vertical lifting support 16 for adjusting the spatial position of the launch tube to adjust the angle of the particles entering the simulated cylinder.

[0040] The launch tube is movable, and the horizontal adjustment support and the vertical lifting support are adjusted to enable solid particles to enter the cylinder and collide with the blades at different spatial angles.

[0041] The blades 4 are placed in the simulated cylinder 3 and are rotated by a motor. The blades are two, 180 degrees apart. The blades are connected to the main shaft of the motor, which drives the blades to rotate at a high speed of 1500-1800 rpm.

[0042] The phase detector 2 is connected to the motor 1 for measuring the phase of the motor. The phase detector 2 is connected to the electromagnetic valve via the synchronizer 5 to control the emitted particles to hit the blades.

[0043] According to the technical solution provided in the present invention, reference Figure 1 The specific implementation plan is as follows:

[0044] 1) Because rotating blades in a simulated cylinder consumes a significant amount of kinetic energy, and considering that impacting multiple blades would require a long experiment, only two blades, spaced 180 degrees apart, were used. The blades were placed in a simulated cylinder filled with high-temperature, high-pressure steam. The blades were connected to the main shaft of a motor, which drove them to rotate at a high speed of 1500 rpm.

[0045] 2) The air compressor generates high-pressure air that enters the air storage tank through a check valve. The pressure in the air storage tank is detected by a pressure sensor. The pressure in the air storage tank is adjusted according to the speed requirement of the accelerated solid particles. The safety of the air storage tank is ensured by safety venting while also adjusting the pressure.

[0046] 3) The exhaust from the air tank is controlled by a solenoid valve, whose opening time is controlled by a synchronizer. A phase detector is installed on the motor and connected to the synchronizer to ensure that the emitted solid particles hit the rotating blades precisely. By controlling the phase difference, the circumferential position where the solid particles collide with the blades can be adjusted.

[0047] 4) Solid particles are supplied by a particle generator, which can provide solid particles of different sizes, shapes and properties according to the actual needs. The solid particle supply time can be controlled manually or by a synchronizer.

[0048] 5) The launch tube is designed to be movable. By adjusting the horizontal rotatable support and the vertical liftable support, solid particles can enter the cylinder and collide with the blades at different spatial angles. The end of the launch tube is equipped with an exhaust pipe and a velocity tube. The exhaust pipe is the outlet for compressed air, and the velocity tube is used to measure the velocity of solid particles entering the cylinder.

[0049] 6) The entire experimental platform can realize the collision of solid particles in different states with blades at various speeds and spatial angles. The position of the collision point can be adjusted to achieve multiple collisions at the same point and discrete collisions at different points, thus achieving full coverage of the collision conditions between solid particles and blades.

[0050] 7) After the experiment is completed, the morphology of the collision point can be microscopically analyzed, and combined with technical means such as residual stress distribution detection and metallographic microstructure detection, qualitative and quantitative analysis of solid particle erosion can be achieved.

[0051] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0052] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A steam turbine blade solid particle erosion test platform, characterized in that: include: Motor, phase detector, simulated cylinder, blades, synchronizer, particle generator, air compressor, air tank, solenoid valve, launch tube; The air compressor is connected to the air storage tank; The solenoid valve is connected to the gas tank, and the synchronizer controls the opening and closing of the solenoid valve; One end of the launch tube is connected to the solenoid valve, and the other end is connected to the simulated cylinder; The launch tube is connected to the particle generator; The connecting end of the launch tube and the simulation cylinder is equipped with an exhaust pipe and a particle velocity measuring tube in sequence; The blades are placed in a simulated cylinder and driven by a motor to rotate; The phase detector is connected to the motor to measure the phase of the motor. The phase detector is connected to the solenoid valve via the synchronizer to control the emitted particles to hit the blades. There are two blades, and the interval between the two blades is 180 degrees.

2. The steam turbine blade solid particle erosion test platform according to claim 1, characterized in that: The launch tube is also equipped with a horizontal adjustment support and a vertical lifting support. It is used to adjust the spatial position of the launch tube to adjust the angle of the particles entering the simulation cylinder.

3. The steam turbine blade solid particle erosion test platform according to claim 1, characterized in that: The gas tank is equipped with a safety release valve and a pressure sensor.

4. The steam turbine blade solid particle erosion test platform according to claim 1, characterized in that: The air compressor is connected to the air storage tank through a check valve.

5. The steam turbine blade solid particle erosion test platform according to claim 1, characterized in that: The transmitting tube and the electromagnetic valve are connected via a connecting hose.

6. The steam turbine blade solid particle erosion test platform according to claim 1, characterized in that: The blades are connected to the main shaft of the motor, and the motor drives the blades to rotate at a high speed of 1500rpm to 1800rpm.

7. The steam turbine blade solid particle erosion test platform according to claim 1, characterized in that: One end of the transmitting tube close to the electromagnetic valve is connected with a particle generator.

8. The steam turbine blade solid particle erosion test platform according to claim 1, characterized in that: The particle generator provides solid particles of different sizes, shapes and properties.

9. The steam turbine blade solid particle erosion test platform according to claim 2, characterized in that: The launch tube is movable, and the horizontal adjustment support and the vertical lifting support are adjusted to enable solid particles to enter the cylinder and collide with the blades at different spatial angles.

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