Device for testing thermal erosion resistance of blade

Abstract

The invention provides a device for testing thermal erosion resistance of a blade, and belongs to the technical field of testing. Comprising a medium storage box in which an erosion medium for testing is stored; the laser generator is used for emitting first heating laser; the clamp is used for fixing the sample; the number of the nozzles is two, the two nozzles both communicate with the medium storage box, the spraying axes of the two nozzles face the emitting axis of the first heating laser and are symmetrically and obliquely arranged, and the two strands of erosion media emitted from the two nozzles intersect and collide on the emitting axis of the first heating laser; the composite jet flow impacts the sample in the injection axis direction of the first heating laser, and the first heating laser heats the composite jet flow. The device has the advantages that a higher momentum concentration ratio is obtained while an erosion medium is heated, and the real service condition of an aero-engine blade under high-temperature and high-speed impact is effectively simulated; and a large heating cavity is not needed, a hearth structure is omitted, the system is greatly simplified, and the cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of testing technology, and in particular relates to a device for testing the thermal erosion resistance of blades. Background Technology

[0002] As core power systems, aero engines and gas turbines have hot-end components (such as turbine blades and guide vanes) that are exposed to high-speed gas flow for extended periods during service. They inevitably ingest solid particles from the atmosphere, such as dust, volcanic ash, and industrial pollutants. These particles soften or even melt under high temperatures and impact the blade surface at high speeds, causing severe coupled damage.

[0003] To evaluate the thermal erosion resistance of materials, existing laboratory testing equipment is generally divided into two categories: one is static or low-speed erosion equipment based on box-type resistance furnace heating, which can preheat samples or particles, but has problems such as slow heating rate and low upper temperature limit; the other is a large-scale simulation platform using combustion heating, which can reproduce real high temperature and high speed environment, but the system is complex, costly, occupies a large area, and has high safety risks, making it difficult to meet the high-frequency, small-batch evaluation needs of the material research and development stage. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a simple structure and fast temperature control response erosion performance testing device.

[0005] The objective of this invention can be achieved through the following technical solution: a blade thermal erosion resistance testing device, comprising: The media storage tank contains the erosion media for testing; A laser generator, which emits a first heating laser; A clamp for fixing the sample, wherein the back of the clamp is provided with an air-cooled cooling component for cooling. There are two nozzles, both of which are connected to the medium storage tank. The spray axes of the two nozzles are oriented toward the emission axis of the first heating laser and are symmetrically inclined. The two streams of erosive medium ejected from the two nozzles converge and collide on the emission axis of the first heating laser to form a composite jet that impacts the sample along the emission axis of the first heating laser. The first heating laser heats the composite jet. A surface laser, which emits a second heating laser to heat the sample.

[0006] In the aforementioned blade thermal erosion resistance testing device, the first heating laser emitted by the laser generator can heat the composite jet to over 1200°C.

[0007] In the aforementioned blade thermal erosion resistance testing device, the shape of the first heating laser beam emitted by the laser generator can be configured and switched according to the testing requirements, so that the area and shape of the laser beam spot change accordingly; wherein, the shape of the laser beam includes at least a linear spot and a planar spot covering the area through which the erosion medium flows.

[0008] The aforementioned blade thermal erosion resistance testing device also includes two temperature detectors, which are used to monitor the temperature of the erosion medium ejected from the nozzle and the temperature of the sample on the fixture, respectively. The temperature detectors are also connected in communication with the laser generator.

[0009] The aforementioned blade thermal erosion resistance testing device also includes a negative pressure adsorber, and the negative pressure adsorber is connected to a negative pressure suction nozzle, which is located on the side of the fixture and is used to absorb the erosion medium after impacting the sample.

[0010] The aforementioned blade thermal erosion resistance testing device further includes a rotating platform capable of rotation. The rotating platform is located on the emission axis of the first heating laser, and the rotation axis of the rotating platform is parallel to but does not coincide with the emission axis of the first heating laser. Multiple clamps are fixedly installed on the rotating platform.

[0011] In the aforementioned blade thermal erosion resistance testing device, an air compressor is connected to the media storage tank, and a pressure regulator is installed on the connecting pipe between the air compressor and the media storage tank.

[0012] In the aforementioned blade thermal erosion resistance testing device, the erosion medium in the medium storage tank includes one or more of calcium magnesium aluminum silicate, molten salt, volcanic ash, and atmospheric dust.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The erosion medium obtains higher momentum concentration while being heated, effectively simulating the real service conditions of aero-engine blades under high temperature and high speed impact. It does not require a large heating cavity, eliminates the furnace structure, greatly simplifies the system, reduces costs, and eliminates response delay caused by thermal inertia. (2) Since the laser heating area is located in the jet space downstream of the nozzle, rather than inside the nozzle or near the outlet, the erosion medium remains at room temperature and has good fluidity when passing through the nozzle; it is only momentarily heated by the laser after leaving the nozzle and on its way to the sample. This design effectively avoids the problems of low-melting-point media such as calcium magnesium aluminum silicate and molten salt melting, adhering, agglomerating or clogging inside the nozzle due to preheating, which significantly improves the operational stability and applicable media range of the device. (3) The front side of the sample is kept at a high temperature under the action of the surface laser heater and the high temperature composite jet, while the back side is kept at a relatively low temperature due to the forced convection cooling of compressed air, thus forming a controllable temperature gradient. This temperature gradient can simulate the typical thermal stress distribution state of "high temperature on the fire-facing side and cooling on the back side" of aero-engine or gas turbine blades in actual operation, and more realistically reflect the damage behavior of materials during service. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the component distribution of the present invention.

[0015] In the diagram, 10 is an air compressor; 11 is a pressure regulator; 12 is a media storage tank; 13 is a nozzle; 14 is an erosion baffle; 20 is a temperature detector; 21 is a laser generator; 22 is a surface laser; 30 is a drive component; 31 is a fixture; 32 is a sample; 33 is a rotating platform; 40 is a negative pressure adsorber; 41 is a negative pressure suction nozzle; and 50 is an air-cooled cooling component. Detailed Implementation

[0016] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0017] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0018] like Figure 1 As shown, in this embodiment, a blade thermal erosion resistance testing device is provided, comprising: The media storage tank 12 is used to store the erosion media for testing. The interior of the media storage tank 12 can be filled with erosion particles simulating real service environments, such as quartz sand, calcium magnesium aluminum silicate, molten salt, volcanic ash, or atmospheric dust. To achieve precise control of the erosion dose, the media storage tank 12 is placed on a high-precision electronic analytical balance to monitor and record the changes in the mass of the media within the media storage tank 12 in real time during the erosion process, thereby accurately calculating the sand output and total erosion dose per unit time.

[0019] Laser generator 21 is used to emit a first heating laser. The first heating laser is emitted in a horizontal direction to form a clear heating axis, which is used to instantaneously heat the erosion medium in flight so that it reaches a set high temperature before impacting the test piece.

[0020] Furthermore, the laser generator 21 is used to emit a first heating laser to preheat the erosion medium. Its output beam shape can be configured or switched according to the test requirements: the emitted laser can be a linear spot or a planar spot covering the area through which the erosion medium flows.

[0021] When a linear laser spot is used, the laser energy is concentrated on the local cross section of the erosion medium flow, which is suitable for simulating the working condition of high-temperature particles impacting the sample in a narrow channel. When switching to a planar laser spot (i.e., planar laser mode), the laser is uniformly spread through the beam shaping optical element to form a heating surface that matches the cross section of the erosion medium flow field. This allows the particles or gas-solid two-phase flow to be uniformly heated as a whole before contacting the sample, more realistically reproducing the composite erosion environment of high-temperature gas carrying hot particles at the gas turbine combustion chamber outlet on the blades.

[0022] The clamp 31 is used to fix the specimen 32. The clamp 31 is made of high temperature resistant alloy and only clamps the edge or root of the specimen to ensure that the front of the specimen (erosion surface) is fully exposed to the environment, while avoiding interference of the clamping area with the thermal field and flow field.

[0023] Nozzles 13 are connected to the medium storage tank 12, and two nozzles 13 are provided. Both nozzles 13 are made of wear-resistant ceramic material and are connected to the medium storage tank 12 via connecting pipes, which are rigid plastic pipes (such as polytetrafluoroethylene or reinforced nylon rigid pipes). The jet axes of the two nozzles 13 are symmetrically inclined and oriented towards the emission axis of the first heating laser emitted from the laser generator 21. When compressed gas drives the erosion medium to be ejected at high speed from the two nozzles 13, the two jets converge and collide at the laser axis, forming a composite jet with higher density and more concentrated kinetic energy, which continuously impacts the sample 32 located downstream along the laser emission direction.

[0024] This structural design enables the erosion medium to achieve higher momentum concentration while being heated, effectively simulating the real service conditions of aero-engine blades under high temperature and high speed impact; it also eliminates the need for a large heating cavity, saves the furnace structure, greatly simplifies the system, reduces costs, and eliminates response delay caused by thermal inertia.

[0025] Because the laser heating zone is located in the jet space downstream of nozzle 13, rather than inside the nozzle or near the outlet, the erosion medium remains at room temperature and has good fluidity as it passes through the nozzle. It is only momentarily heated by the laser after leaving nozzle 13 and while flying towards sample 32. This design effectively avoids the problems of low-melting-point media such as calcium magnesium aluminum silicates and molten salts melting, adhering, agglomerating, or clogging inside nozzle 13 due to preheating, significantly improving the operational stability and applicable media range of the device.

[0026] Laser heating is a non-contact, highly concentrated radiative heating method that can rapidly raise the temperature of the erosion medium to the target temperature within milliseconds to seconds. Traditional heating furnaces, on the other hand, rely on heat conduction and convection, and their heating rate is limited by the thermal inertia of the furnace chamber, typically requiring tens of minutes or even longer to reach the same temperature, making them unsuitable for the dynamic demands of high-speed erosion experiments. Furthermore, the laser generator 21 used in this device has adjustable output power, and in conjunction with the focusing optical system, can heat the composite jet to over 1200°C, exceeding the practical upper limit of most conventional resistance furnaces in miniaturized equipment.

[0027] Furthermore, the device also includes a surface laser 22, which emits a second heating laser. The second heating laser is a laser heating surface with a large coverage area, which faces the sample 32 on the fixture 31 to uniformly heat its entire surface. The surface laser 22 employs a homogenizing optical system to expand the high-energy laser into an irradiation surface with a certain area and energy uniformity, effectively covering the entire erosion area of ​​the sample 32.

[0028] The temperature of the laser-heated surface is controllable, simulating the thermal load on the blades from the high-temperature combustion gas environment at the combustion chamber outlet of an aero-engine or gas turbine. In this mode, the sample 32 not only withstands the local impact of high-speed, high-temperature particles but is also in a large-area, steady-state high-temperature radiation field, more realistically reproducing the coupled damage mechanism of high-temperature background plus particle erosion in actual service of hot-end components. Furthermore, a cooling air component 50 is provided on the back of the fixture 31 for cooling. This cooling air component 50 consists of one or more sets of compressed air nozzles, facing the non-erosion surface (i.e., the back) of the fixture 31, continuously or as needed spraying room-temperature or low-temperature compressed air during the test. The front of the sample 32 maintains a high-temperature state under the high-temperature heating effect of the surface laser 22, while the back remains relatively low-temperature due to forced convection cooling by compressed air, thus forming a controllable temperature gradient. This temperature gradient can simulate the typical thermal stress distribution state of "high temperature on the front side and cooling on the back side" of aero-engine or gas turbine blades in actual operation, more realistically reflecting the damage behavior of materials during service. In addition, the air-cooled cooling component 50 can effectively prevent the fixture 31 from thermal deformation due to prolonged heating. The compressed air flow rate and pressure are adjustable, making it easy to flexibly set the cooling intensity according to the material, thickness and target temperature gradient of the sample 32.

[0029] The aforementioned device also includes an erosion baffle 14, which is disposed between the laser generator 21 and the fixture 31, and located on the impact axis of the composite jet. The erosion baffle 14 has two working positions: First position: The erosion baffle 14 is located on the composite jet path, completely blocking the jet and preventing it from contacting the sample 32; Second position: The erosion baffle 14 is moved out of the composite jet path and no longer in contact with the composite jet, allowing the jet to directly impact the surface of the sample 32.

[0030] At the beginning of the experiment, the erosion baffle 14 is in the first position, blocking the initially ejected erosion medium. Since the airflow pressure, sand output rate, or particle temperature may fluctuate during the initial system startup, the erosion conditions are not yet stable. The erosion medium is allowed to spray for a few seconds and be intercepted by the erosion baffle 14. Once the system is running smoothly and reaches the specified temperature, the erosion baffle 14 is quickly switched to the second position, and the timer is started to begin the formal erosion test. After the erosion time is completed, the erosion baffle 14 can be reset to the first position to ensure that no residual particles impact the specimen during shutdown.

[0031] It also includes temperature detectors 20, which are non-contact infrared temperature detectors, and there are two of them. One of the temperature detectors 20 is aligned with the first position of the erosion baffle 14, which is located on the path through which the erosion medium flows, and is used to monitor the temperature of the erosion medium in real time before impacting the sample 32. The temperature detector 20 is communicatively connected to the laser generator 21. When the temperature of the erosion medium is detected to be lower than a preset threshold, it sends a signal to the laser generator 21 to increase its output power and enhance the preheating intensity of the erosion medium. When the temperature reaches or exceeds the upper limit, it maintains or reduces its output power to ensure that the erosion medium is always within the target temperature range.

[0032] Another temperature detector 20 is positioned on the eroded surface of the sample 32 on the fixture 31 to monitor the surface temperature of the sample 32 during the erosion process. It is communicatively connected to the laser generator 21 and the surface laser 22. When the surface temperature of the sample 32 deviates from the set value, the output power of the laser generator 21 or the surface laser 22 is adjusted accordingly to achieve dynamic and stable control of the sample 32's body temperature, effectively simulating the real thermal state of aero-engine or gas turbine blades under high-temperature service conditions.

[0033] Furthermore, the device also includes a negative pressure adsorber 40, which is connected to a negative pressure suction nozzle 41 via a pipe. The negative pressure suction nozzle 41 is installed beside the clamp 31, with its suction inlet facing the erosion area, and is used to adsorb and collect the erosion medium that rebounds, scatters, or does not adhere after impact and collision in real time during the erosion process. When the erosion medium impacts the surface of the sample 32 at high speed and rebounds and splashes, its kinetic energy decays rapidly. These rebounding particles that lose their directionality are captured by the dominant airflow field established by the negative pressure suction nozzle 41 during the diffusion process, and are forcibly guided and sucked into the nozzle.

[0034] The aforementioned negative pressure adsorber 40 cleverly utilizes the instantaneous decrease in kinetic energy of the eroded medium after impact, employing a pre-set strong airflow field for bottom-collection, while also physically avoiding direct interference with the high-speed incident jet. This effectively controls the diffusion of high-temperature media, protects precision components such as infrared thermometers, and ensures operational safety.

[0035] Furthermore, it also includes a rotating platform 33, on which multiple clamps 31 are provided. Each clamp 31 is evenly distributed along the circumference of the rotating platform 33 for simultaneously mounting multiple samples 32. During the experiment, the rotating platform 33 is driven by a drive component 30 (such as a servo motor or stepper motor) to rotate intermittently or continuously according to a preset program.

[0036] The rotating platform 33 is positioned in the direction of the heating laser emission, with its rotation axis parallel to but not coinciding with the emission axis of the heating laser. This arrangement allows the sample 32 on the rotating platform 33 to sequentially enter the combined jet and laser heating regions as the platform rotates. Multiple samples 32 can be continuously tested for thermal erosion performance with a single sample loading, significantly improving experimental efficiency.

[0037] Furthermore, the rotating platform 33 drives the sample 32 to rotate at high speed. The sample 32 (simulated blade) mounted on the fixture 31 is subjected to centrifugal load during the test, thereby realistically reproducing the mechanical environment generated by the high-speed rotation of blades in aero-engines or gas turbines during actual service.

[0038] Furthermore, an air compressor 10 is connected to the media storage tank 12 to provide the power air source for driving the erosion medium. The compressed air output by the air compressor 10 is introduced into the bottom or side wall of the media storage tank 12 through the pipeline, so as to form a positive pressure inside the tank, thereby pressurizing the erosion medium to the nozzle 13.

[0039] A pressure regulator 11 is installed on the connecting pipeline between the air compressor 10 and the media storage tank 12. The pressure regulator 11 is used to precisely control the gas pressure entering the media storage tank 12. By adjusting the pressure value, the jet speed and kinetic energy of the erosion medium can be linearly controlled, thereby simulating particle impact conditions at different flight speeds (such as low-speed sand and dust erosion or high-speed volcanic ash impact).

[0040] It should be noted that when the laser generator 21 is not turned on, it can simulate the ambient temperature erosion condition of a compressor blade. In this mode, both the surface laser 22 and the laser generator 21 used to heat the erosion medium remain off. The erosion medium is ejected at high speed from the nozzle 13 at ambient temperature, impacting the sample which is at ambient temperature. At the same time, the rotating platform 33 can still rotate at high speed as needed to apply centrifugal force.

[0041] By flexibly opening and closing the laser heating system, this device can seamlessly switch between two typical working conditions, high-temperature thermal erosion and normal-temperature erosion, on the same platform, significantly improving the versatility of the equipment and research efficiency.

[0042] A method for testing the thermal erosion resistance of blades includes the following steps: S1. Clamp the sample 32 onto the fixture 31; S2: Add the specified erosion medium to the media storage box 12. The erosion medium can be gravel, calcium magnesium aluminum silicate, molten salt, volcanic ash, atmospheric dust, etc. S3: Sets the erosion pressure, sand feed rate, erosion medium heating temperature, sample 32 heating temperature, and drive unit 30 rotation speed. The sand discharge speed of nozzle 13 can be adjusted according to the erosion pressure, and the sand feed rate is adjusted via a flow controller. S4: Activate the air-cooled cooling component 50, negative pressure adsorber 40, drive component 30, temperature detector 20, laser generator 21 and surface laser 22, and impact and erode the baffle 14 before reaching the specified temperature and speed. S5: After the experimental conditions are met, remove the erosion baffle 14, conduct the erosion test, and record the erosion time. Calculate the total sand output by recording the erosion time. S6: The erosion test is complete. Turn off the above instruments. The sample 32 and nozzle 13 still have residual heat, and the drive component 30 has not yet stopped moving. The next step can only be carried out after the infrared temperature detector 20 shows that the sample 32 has cooled to room temperature and the drive component 30 has completely stopped. S7: After sample 32 cools to room temperature, turn off infrared temperature detector 20, remove sample 32, and clean the test platform. After removing sample 32, parameters such as erosion rate per unit area, erosion morphology, and adhesion rate of sample 32 can be evaluated.

[0043] It should be noted that in this invention, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0045] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A device for testing the thermal erosion resistance of blades, characterized in that, include: The media storage tank contains the erosion media for testing; A laser generator, which emits a first heating laser; A clamp for fixing the sample, wherein the back of the clamp is provided with an air-cooled cooling component for cooling. There are two nozzles, both of which are connected to the medium storage tank. The spray axes of the two nozzles are oriented toward the emission axis of the first heating laser and are symmetrically inclined. The two streams of erosive medium ejected from the two nozzles converge and collide on the emission axis of the first heating laser to form a composite jet that impacts the sample along the emission axis of the first heating laser. The first heating laser heats the composite jet. A surface laser, which emits a second heating laser to heat the sample.

2. The blade thermal erosion resistance testing device according to claim 1, characterized in that, The first heating laser emitted by the laser generator can heat the composite jet to over 1200°C.

3. The blade thermal erosion resistance testing device according to claim 1, characterized in that, The shape of the first heated laser beam emitted by the laser generator can be configured and switched according to the test requirements, so that the area and shape of the laser beam spot change accordingly; wherein, the shape of the laser beam includes at least a linear spot and a planar spot covering the area through which the erosion medium flows.

4. The blade thermal erosion resistance testing device according to claim 1, characterized in that, It also includes two temperature detectors, which are used to monitor the temperature of the erosion medium ejected from the nozzle and the temperature of the sample on the fixture, respectively, and the temperature detectors are communicatively connected to the laser generator.

5. The blade thermal erosion resistance testing device according to claim 1, characterized in that, It also includes a negative pressure adsorber, and the negative pressure adsorber is connected to a negative pressure suction nozzle, which is located on the side of the fixture and is used to absorb the erosion medium after impacting the sample.

6. The blade thermal erosion resistance testing device according to claim 1, characterized in that, It also includes a rotating platform that can rotate, the rotating platform being located on the emission axis of the first heating laser, and the rotation axis of the rotating platform being parallel to but not coincident with the emission axis of the first heating laser, and multiple clamps being fixedly installed on the rotating platform.

7. The blade thermal erosion resistance testing device according to claim 1, characterized in that, An air compressor is connected to the media storage tank, and a pressure regulator is installed on the connecting pipe between the air compressor and the media storage tank.

8. The blade thermal erosion resistance testing device according to claim 1, characterized in that, The erosion media in the media storage tank include one or more of calcium magnesium aluminum silicate, molten salt, volcanic ash, and atmospheric dust.

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