Method and system for testing ice prevention performance of electric heating ice prevention fan blade

Abstract

The application relates to an ice prevention performance test method and system for an electric heating ice prevention fan blade. First, a single target blade to be tested in the electric heating ice prevention fan blade is fixed on a rotating disc of a wind tunnel test section through a support fastening device, and the initial installation angle of the target blade is adjusted by controlling the rotation of the rotating disc to match the installation state of the target blade on the hub. Then, the wind tunnel parameters of the wind tunnel test section are adjusted, and the ice prevention performance of the target blade is tested based on each wind tunnel parameter. The application simulates various complex working conditions by adjusting the wind tunnel parameters, and tests the ice prevention performance for each working condition, so that the test data of the icing area and the ice prevention effect are closer to the actual operation scene. In this way, the adaptability of the ice prevention performance test to diversified scenes is improved, and the data reliability of the ice prevention performance test is also improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind tunnel test, in particular to an anti-icing performance test method and system for electrically heated anti-icing fan blades. BACKGROUND

[0002] In the process of icing wind tunnel test, low-temperature cloud water droplets generated by the front spray system will circulate in the wind tunnel with the airflow. When the water droplets collide with the fan blades, they will form growing ice type on the leading edge of the fan blades, thereby changing the shape of the fan blades and affecting the aerodynamic performance of the blades. Moreover, after icing of multiple blades, ice shedding may occur in individual blades, which may occur at times and be uneven among the blades, thereby changing the mass center distribution of the fan rotor system and destroying the dynamic balance of the rotor system during high-speed rotation, which may cause safety hazards. Therefore, in addition to the conventional low-speed wind tunnel fan blades, the icing wind tunnel fan blades also need to add anti-icing function to prevent icing on the leading edge of the fan blades during long-time spray icing test, which may affect the aerodynamic performance of the blades and even destroy the dynamic balance of the fan segment rotor system.

[0003] Generally, the fan blades used in large-scale icing wind tunnel test are provided with electric heating components on the leading edge, and the blades are prevented from icing by electric heating. Therefore, such blades are also called electrically heated anti-icing fan blades, that is, an electrically heated anti-icing device is installed on the leading edge of the blades to realize the electrically heated anti-icing function. However, the application of electrically heated anti-icing fan blades is not mature enough, especially the understanding of the electrically heated anti-icing performance of the blades is not thorough enough. Therefore, during the use of the electrically heated anti-icing fan blades in the icing wind tunnel test, the electric heating area of the leading edge is widened as much as possible in the structural design, and the anti-icing power is set as high as possible. The traditional electric heating area is a fixed area, which cannot adapt to different working conditions and increases the manufacturing cost and waste of power supply energy of the blades. Moreover, the electrically heated anti-icing fan blades are directly installed on the fan segment hub for testing. When the whole fan blades rotate, complex airflow disturbance may occur between different blades, which may cause significant deviation between the actual parameters and the theoretical parameters of each blade. Therefore, the simulation of complex icing conditions by multiple blades has inherent limitations, and it is not easy to observe the anti-icing effect of the fan blades during rotation. SUMMARY

[0004] The purpose of the present application is to provide an anti-icing performance test method and system for electrically heated anti-icing fan blades, which can solve the problem of low accuracy of the anti-icing performance test of electrically heated anti-icing fan blades.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present application provides an anti-icing performance test method for electrically heated anti-icing fan blades, comprising:

[0006] The single target blade to be tested in the electric heating anti-icing fan blade is fixed on the rotating disc of the wind tunnel test section through the supporting and fastening device, and the initial installation angle of the target blade is adjusted by rotating the control rotating disc to match the installation state of the target blade on the hub;

[0007] The wind tunnel parameters of the wind tunnel test section are adjusted, and the anti-icing performance of the target blade is tested based on each wind tunnel parameter respectively, and the wind tunnel parameters include the incoming flow wind speed and the cloud and mist parameters;

[0008] The step of testing the anti-icing performance of the target blade based on each wind tunnel parameter respectively includes:

[0009] The incoming flow wind speed is combined with the linear speed of the target blade in rotation to obtain the fitting speed of the target blade in operation, and the angle of the rotating disc is adjusted based on the fitting speed to match the airflow direction of the wind tunnel test section with the airflow angle of the target blade in operation;

[0010] The cloud and mist parameters are set based on the fitting speed, the leading edge icing area range of the target blade is measured after running for a first set time, and the electric heating assembly is set in the leading edge icing area range;

[0011] The heating power of the electric heating assembly of the target blade is adjusted from high to low, and the anti-icing critical power of the target blade is determined.

[0012] The second aspect of the application provides an anti-icing performance testing system of an electric heating anti-icing fan blade, which comprises a target blade, a wind tunnel test section, a supporting and fastening device and a controller;

[0013] The target blade is a single blade to be tested in the electric heating anti-icing fan blade;

[0014] The wind tunnel test section comprises a rotating disc;

[0015] The target blade is fixed on the rotating disc of the wind tunnel test section through the supporting and fastening device;

[0016] The controller stores a program which can be loaded and executed by the processor to perform the above-mentioned anti-icing performance testing method.

[0017] The application has the following beneficial effects:

[0018] Firstly, the single target blade to be tested in the electrothermal anti-icing fan blade is fixed on the rotating disc of the wind tunnel test section through the support fastening device, and the initial installation angle of the target blade is adjusted by controlling the rotation of the rotating disc to match the installation state of the target blade on the hub. Compared with the airflow turbulence caused by the interference of multiple blades in the whole fan test, the single target blade can exclude the mutual influence of the blades. Then, the wind tunnel parameters of the wind tunnel test section are adjusted, and the anti-icing performance test of the target blade is carried out based on each wind tunnel parameter respectively. Specifically, firstly, the fitting speed of the target blade is obtained based on the incoming flow speed and the rotating speed of the target blade, and the angle of the rotating disc is adjusted based on the fitting speed to match the airflow direction of the wind tunnel test section with the airflow angle of the target blade in operation. Then, the cloud parameters are set based on the fitting speed, and the electric heating assembly is set in the leading edge icing area, and the anti-icing critical power of the target blade is determined by adjusting the heating power of the electric heating assembly. By adjusting the wind tunnel parameters, various complex working conditions are simulated, and the anti-icing performance test is carried out for each working condition. Through the double real simulation of the installation state and the airflow condition, the data of the icing area and the anti-icing effect and the like are closer to the actual operation scene. In this way, the adaptability of the anti-icing performance test to diversified scenes is improved, and the data reliability of the anti-icing performance test is also improved.

[0019] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A flowchart of an anti-icing performance test method of an electrothermal anti-icing fan blade provided in an embodiment of the present application is shown;

[0021] Figure 2 A structure diagram of a target blade provided in an embodiment of the present application is shown;

[0022] Figure 3 A structure diagram of a sleeve provided in an embodiment of the present application is shown;

[0023] Figure 4 A cross-sectional view of a sleeve provided in an embodiment of the present application is shown;

[0024] Figure 5 A connection relationship diagram of a blade stem shaft and a sleeve provided in an embodiment of the present application is shown;

[0025] Figure 6 A structure diagram of a connection between a blade stem shaft and a sleeve provided in an embodiment of the present application is shown;

[0026] Figure 7 A structure diagram of a nut provided in an embodiment of the present application is shown;

[0027] Figure 8A structure diagram of a nut and a target blade locking provided in an embodiment of the present application;

[0028] Figure 9 A structure diagram of a force bearing key provided in an embodiment of the present application;

[0029] Figure 10 A structure diagram of an end cover provided in an embodiment of the present application;

[0030] Figure 11 A structure diagram of an end cover and sleeve support seat locking provided in an embodiment of the present application;

[0031] Figure 12 A structure diagram of an ice prevention performance test system of an electric heating ice prevention fan blade provided in an embodiment of the present application;

[0032] Figure 13 A vector representation diagram of a fitting speed provided in an embodiment of the present application.

[0033] Explanation of reference signs

[0034] 1, target blade; 11, blade body; 12, blade handle shaft; 121, first circular surface; 122, second circular surface; 123, thread; 124, first key groove; 2, wind tunnel test section; 21, rotating disc; 3, support fastening device; 31, sleeve; 311, sleeve support seat; 312, sleeve surface; 313, first inner circular surface; 314, second inner circular surface; 32, nut; 321, first threaded hole; 33, force bearing key; 34, end cover; 341, second key groove. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0036] In the description of the present application, it is understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified. In the present application, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Any embodiment described as "exemplary" in the present application is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to practice and use the present application. In the following description, details are set forth for the purpose of explanation. It will be appreciated that one of ordinary skill in the art can realize and implement the present application without the use of these specific details. In other instances, well-known structures and processes have not been described in detail in order to avoid unnecessarily obscuring the description of the present application. Therefore, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

[0037] Figure 1 A flowchart of an ice prevention performance test method for an electrothermal ice prevention fan blade provided in an embodiment of the present application. As shown in Figure 1 the ice prevention performance test method can include steps 100 and 200, which are described in detail below.

[0038] Step 100, fix the single target blade to be tested in the electrothermal ice prevention fan blade to the turntable of the wind tunnel test section through the support fastening device, adjust the initial installation angle of the target blade by controlling the rotation of the turntable, so that the target blade matches the installation state of the target blade on the hub.

[0039] The present application adopts single blade for testing, therefore, first select a single blade in the electrothermal ice prevention fan blade as the target blade, which is the blade to be tested. Then, design a support fastening device for fixing the target blade to the turntable of the wind tunnel test section. Wherein, the wind tunnel test section refers to the device for conducting wind tunnel experiment, i.e. conducting ice prevention performance test. The wind tunnel test section is provided with a turntable, by controlling the rotation of the turntable, the state of the target blade can be adjusted, such as the initial installation angle. In one example, the turntable can be driven by a servo motor, and the encoder feedbacks the angle in real time, so as to ensure that the initial installation angle of the target blade matches the installation state of the target blade on the hub. By testing a single target blade, the influence of inter-blade wake and turbulent flow in the whole fan test can be reduced, so that the airflow directly acts on the test blade, and the icing area can be closer to the real working condition.

[0040] Step 200, adjust the wind tunnel parameters of the wind tunnel test section, and test the anti-icing performance of the target blade based on each wind tunnel parameter respectively.

[0041] The wind tunnel parameters are parameters reflecting the working conditions for testing the anti-icing performance, which can include the incoming flow speed and cloud and mist parameters. The incoming flow speed refers to the speed of the airflow blowing directly in front of the target blade. When the set incoming flow speed is received, the wind speed can be controlled by the closed-loop control of the wind tunnel frequency conversion fan. The cloud and mist parameters are parameters simulating the cloud and mist environment of the working condition, such as liquid water content and water droplet size, etc. The cloud and mist parameters and the incoming flow speed can be data with a mapping relationship, representing the wind tunnel parameters of a working condition. Through the combination of the incoming flow speed and the cloud and mist parameters, the icing environment of multiple scenes such as high-altitude cruising, take-off and landing can be simulated, and the test results can be applied to the anti-icing design of the whole life cycle of the target blade. Moreover, the closed-loop control of the incoming flow speed and the cloud and mist parameters can ensure the stability of the cloud and mist parameters during the test process, reduce the abnormal icing patterns caused by parameter switching, improve the repeatability of the data, and make the test results of the same working condition have smaller deviation.

[0042] In step 200, the anti-icing performance test for each wind tunnel parameter can include the following steps.

[0043] Step 201, synthesize the set incoming flow speed and the rotational linear speed of the target blade to obtain the fitting speed of the target blade in operation, and adjust the angle of the turntable based on the fitting speed to match the airflow direction of the wind tunnel test section with the airflow angle of the target blade in operation.

[0044] When the target blade is tested, the operating speed condition of the target blade needs to be simulated first. When the target blade is installed on the fan section hub, in addition to the incoming flow speed, there is also the linear speed generated by the rotation of the target blade itself. Therefore, when the target blade is tested, the speeds of the two need to be fitted. Therefore, the fitting speed refers to the speed after the synthesis of the incoming flow speed and the rotational linear speed of the target blade. Adjusting the angle of the turntable based on the calculated fitting speed can make the airflow direction that the target blade bears in the test consistent with the actual operation, solve the problem of icing area deviation caused by single incoming flow direction in traditional wind tunnel test, and provide accurate input for subsequent cloud and mist parameter setting and anti-icing power calculation, improving the physical authenticity of the test model.

[0045] Step 202, set the cloud and mist parameters based on the fitting speed, measure the leading edge icing area range of the target blade after running for a first set time, and set the electric heating assembly in the leading edge icing area range.

[0046] The combination of the fitting speed and the cloud and fog parameters in the embodiments of the present application can cover various working conditions, such as continuous maximum icing and intermittent maximum icing, and provide more comprehensive and direct data support for the initial state of the target blade. The first setting time is the duration for observing the icing image of the target blade. After running for the first setting time, the icing area range of the leading edge of the target blade can be measured, and the area size of the electric heating assembly is arranged in the icing area range. In this way, the heating layout is customized as needed, and the heating assembly can be set according to the actual icing area instead of empirical values, reducing the case of overdesign, saving the layout cost of the electric heating assembly, and reducing the energy consumption of heating. Moreover, the icing area under different working conditions can be analyzed differently, for example, the icing area expands under the working condition of high speed and large particle size, providing a design basis for a multi-working-condition adaptive anti-icing system.

[0047] In step 203, the heating power of the electric heating assembly of the target blade is adjusted from high to low, and the anti-icing critical power of the target blade is determined.

[0048] After the electric heating assembly is arranged, the heating power of the electric heating assembly can be controlled. Generally, a higher power does not cause icing, but during the process of adjusting the power from high to low, the leading edge of the target blade will slowly start to ice. The state of just starting to ice is the critical anti-icing state. Therefore, the heating power of the electric heating assembly can be controlled to change from high to low, and then the anti-icing critical power of the target blade is found out. In subsequent tests, the anti-icing power of the target blade can be adjusted according to the test parameters, which can not only achieve the anti-icing function but also save the power supply energy. By determining the lowest effective power, the energy consumption of the anti-icing system can be greatly reduced, the material aging caused by high temperature can be reduced, and the service life of the target blade can be prolonged. Based on the anti-icing critical power, the relationship between the working condition and the power mapping can be established to support intelligent power adjustment in actual operation, thereby improving the adaptability and safety of the anti-icing system.

[0049] By controlling the rotation of the rotating disc to adjust the initial installation angle of a single target blade, the embodiments of the present application can match the installation state of the target blade with the target blade on the hub. Compared with the airflow turbulence caused by the interference of multiple blades in the whole fan test, the single target blade can exclude the mutual influence of the blades. Then, the wind tunnel parameters of the wind tunnel test section are adjusted to simulate various complex working conditions, and the anti-icing performance of the target blade is tested based on each wind tunnel parameter respectively. In this way, through the dual real simulation of the installation state and the airflow working condition, the data of the icing area and the anti-icing effect and other tests are closer to the actual operation scene. In the case of improving the adaptability of the anti-icing performance test to diversified scenes, the data reliability of the anti-icing performance test is also improved.

[0050] In order to more clearly illustrate the anti-icing performance test method of the electric heating anti-icing fan blade according to the embodiments of the present application, the structure of the target blade, the fastening device and the wind tunnel test section will be described first.

[0051] Figure 2 A schematic diagram of the structure of a target blade provided in an embodiment of the present application is shown. As shown in the figure, in the embodiment of the present application, the target blade 1 can include a blade body 11 and a blade stem shaft 12, and the blade stem shaft 12 can include a first circular surface 121, a second circular surface 122, a thread 123, and a first key groove 124. The first circular surface 121 is arranged at a first end of the blade stem shaft 12, and the second circular surface 122, the thread 123, and the first key groove 124 are arranged at a second end of the blade stem shaft 12, and the first end of the blade stem shaft 12 is close to the blade body 11. Figure 2

[0052] The structure for supporting the connection of the target blade 1 is the blade stem shaft 12. Two circular surfaces, i.e., the first circular surface 121 and the second circular surface 122, are arranged at both ends of the blade stem shaft 12 as two support points, for bearing the aerodynamic force of the target blade 1 under wind load. At the same time, the structure locking of the thread 123 of the blade stem shaft 12 is used to bear the centrifugal force of the target blade 1. The first key groove 124 is used to set a force-bearing key to limit the swing of the target blade 1.

[0053] In the embodiment of the present application, the supporting and fastening device can include a sleeve, a nut, a force-bearing key, and an end cap.

[0054] Figure 3 A schematic diagram of the structure of a sleeve provided in an embodiment of the present application is shown. Figure 4 A schematic diagram of the cross section of a sleeve provided in an embodiment of the present application is shown. As shown in the figures, Figure 3 and Figure 4 In order to match the circular surface of the blade stem shaft 12, the structure of the sleeve 31 is designed. The sleeve 31 can include a sleeve support seat 311 and a sleeve surface 312. The inner hole of the sleeve surface 312 is provided with a first inner circular surface 313 and a second inner circular surface 314.

[0055] Figure 5 A schematic diagram of the connection relationship between the blade stem shaft and the sleeve provided in an embodiment of the present application is shown. Figure 6 A schematic diagram of the structure of the connection between the blade stem shaft and the sleeve provided in an embodiment of the present application is shown. As shown in the figures, Figure 5 and Figure 6 The first inner circular surface 313 matches the first circular surface 121 on the blade stem shaft 12 of the target blade 1. The second inner circular surface 314 matches the second circular surface 122 on the blade stem shaft 12 of the target blade 1. The remaining details of the structure of the sleeve 31 are designed to meet the connection and strength and rigidity requirements under high wind speed in the test time domain wind tunnel test section. The blade stem shaft 12 is inserted into the inner hole of the sleeve 31 structure, and the two circular surfaces of the blade stem shaft 12 are matched and connected with the two circular surfaces of the inner hole of the sleeve 31, so that the force transmission of the blade stem shaft 12 to the sleeve support seat 311 is realized. ​

[0056] Figure 7 A structural schematic diagram of a nut provided in an embodiment of the present application. Figure 8 A structural schematic diagram of a nut and a target blade locking provided in an embodiment of the present application. As shown in Figure 7 and Figure 8 , according to the thread 123 of the handle shaft 12, a nut 32 can be designed. The inner hole thread of the nut 32 matches the thread 123 of the handle shaft 12, that is, the inner hole thread of the nut 32 is consistent with the thread 123 of the handle shaft 12, for locking the target blade 1 to the sleeve support seat 311. In an example, the outer shape of the nut 32 can be designed as an outer hexagonal structure, facilitating the use of a large size wrench to tighten. At the same time, a plurality of first threaded holes 321 can be provided on the nut 32 for connecting with the end cover 34.

[0057] Figure 9 A structural schematic diagram of a force bearing key provided in an embodiment of the present application. Figure 10 A structural schematic diagram of an end cover provided in an embodiment of the present application. As shown in Figure 9 and Figure 10 , the force bearing key 33 is built into the first key groove 124, that is, it is placed in the key groove hole position of the handle shaft 12. And the force bearing key 33 is embedded with the second key groove 341 on the inner side of the end cover 34, so as to limit the axis swing of the target blade 1. At the same time, in order to avoid the nut 32, a part of the inside of the end cover 34 can be hollowed out. A plurality of through holes can be provided on the circumference of the end cover 34 for the subsequent passing of fastening screws. After the second key groove 341 passes through the force bearing key 33 placed in the handle shaft 12, the swing rotation force of the target blade 1 can be transmitted to the end cover 34.

[0058] Figure 11 A structural schematic diagram of an end cover and a sleeve support seat locking provided in an embodiment of the present application. As shown in Figure 11 , the end cover 34 is fixed to the sleeve support seat 311 and matches the plurality of first threaded holes 321 of the nut 32, so as to realize the locking of the nut 32 and the end cover 34. The second key groove 341 of the end cover 34 is inserted along the handle shaft key position, and a plurality of screws are used to pass through the through holes on the circumference of the end cover 34 to lock the end cover to the sleeve support seat 311 (the bottom surface of the sleeve support seat 311 is arranged with corresponding threaded holes), and a plurality of screws are used to pass through the waist-shaped second key groove 341 of the end cover 34 to lock the nut 32.

[0059] Figure 12 A structural schematic diagram of an anti-icing performance test system of an electric heating anti-icing fan blade provided in an embodiment of the present application. As shown in Figure 12As shown, the anti-icing performance test system includes a target blade 1, a wind tunnel test section 2, and a support fastening device 3 and a controller (not shown in the figure). The target blade 1 is a single blade to be tested in the electrothermal anti-icing fan blade. The wind tunnel test section 2 includes a rotating disc 21. The target blade 1 is fixed to the rotating disc 21 of the wind tunnel test section by the support fastening device 3. The controller stores a program that can be loaded and executed by a processor to perform any of the anti-icing performance test methods in the embodiments of the present application.

[0060] In the embodiments of the present application, the target blade 1 can be installed at the center of the wind tunnel test section 2, and a plurality of screws can be used to lock the support fastening device 3 on the rotating disc 21 of the wind tunnel test section 2. In one example, the rotating disc 21 has a circular structure and is provided with uniformly distributed second threaded holes (not shown in the figure) that match the sleeve support seat 311 to fix the support fastening device 3 to the rotating disc 21. The rotating disc can rotate around its own axis and the rotation angle is adjustable.

[0061] Based on the above anti-icing performance test system of the electrothermal anti-icing fan blade, the steps of testing the anti-icing performance of the target blade based on each wind tunnel parameter in the embodiments of the present application are described below.

[0062] In step 201, the incoming flow wind speed of the wind tunnel test section can be obtained first, which is used to simulate the forward airflow speed that the target blade receives in operation. As an example, a Pitot tube anemometer can be used as a main sensor and installed at the inlet of the wind tunnel test section, and two auxiliary wind speed sensors can be arranged at the outlet of the wind tunnel test section, and the average value of the three points is taken as the final incoming flow wind speed.

[0063] Then, based on the reference profile radius of the target blade and the actual rotation speed, the rotational linear speed of the target blade is calculated. The reference profile of the target blade can be the profile at a certain blade height position of the blade to reflect the ice layer growth significantly. Then the distance from the profile to the rotation line is measured by a laser range finder, i.e. the rotation radius. The rotational linear speed of the target blade can be expressed as , is the actual rotation speed of the target blade, is the rotation radius of the reference profile, which can be determined according to the design parameters of the target blade.

[0064] Finally, according to the vector of the incoming flow wind speed and the rotational linear speed, the fitting speed is calculated by the vector composition rule. The vector direction of the incoming flow wind speed is along the wind tunnel axis from front to back, which is perpendicular to the rotation plane of the target blade, i.e. the transverse airflow. The vector direction of the rotational linear speed is along the tangent direction of the target blade rotation, which is perpendicular to the radial direction of the target blade, i.e. the circumferential speed. They are perpendicular to each other in space and can form adjacent sides of vector composition.

[0065] Figure 13 A vector representation of the fitting velocity is provided in an embodiment of the present application. For example, the incoming flow wind speed in front of the target blade is 50 m / s, the actual rotating speed of the target blade is 300 rpm, and the linear rotating speed of the target blade calculated based on the reference profile (e.g., the radius of about 3 meters at the position of 70%) is 94 m / s. Therefore, the sum of the fitting velocities can be 106.5 m / s.

[0066] As an example, a parallelogram can be formed by a first vector corresponding to the incoming flow wind speed and a second vector corresponding to the linear rotating speed. The speed magnitude is calculated by the Pythagorean theorem based on the first vector and the second vector. The offset angle relative to the incoming flow wind speed is calculated by the arctangent function based on the first vector and the second vector. Finally, the fitting velocity is obtained based on the speed magnitude and the offset angle. The force state of the target blade in actual operation can be directly mapped by the vector composition method, and the calculation result provides reference data for subsequent adjustment of the rotating disc angle and setting of the cloud and mist parameters, so as to match the test with the actual working condition.

[0067] In step 201, after the fitting velocity is calculated, the rotating disc can be controlled to rotate. When it is detected that the normal direction of the leading edge of the target blade matches the direction of the offset angle, the rotation of the rotating disc is stopped.

[0068] The angle at which the rotating disc needs to rotate is consistent with the offset angle in the fitting velocity, and the angle is the actual incident angle of the airflow relative to the blade. The rotating disc is rotated so that the normal direction of the leading edge of the target blade matches the direction of the fitting velocity vector, and the airflow accurately hits the leading edge of the target blade at the offset angle, so as to simulate the direction of the airflow in actual operation and reduce the deviation of the icing area caused by the angle deviation.

[0069] In the case where the fitting velocity changes, the direction of the incoming flow wind speed relative to the blade also changes while the fitting velocity magnitude changes. The offset angle can be recalculated and the rotating disc can be driven to rotate to a new angle, so as to ensure the test accuracy in different working conditions. For example, the speed angle deviates by 28°. During the test, since the direction of the incoming flow wind speed of the wind tunnel test section does not change from front to back, the rotating disc of the wind tunnel test section needs to be rotated by 28°, so as to ensure the consistency of the direction of the test wind speed and the actual use state.

[0070] In step 202, the cloud and fog parameters having a mapping relationship with the fitting speed can be determined first. The cloud and fog parameters can include the temperature of the wind tunnel test section, the liquid water content, the cloud and fog water droplet particle size, and the first set time. Among them, the mapping relationship between the cloud and fog parameters and the fitting speed can be established based on the correlation between the airflow speed and the water droplet motion characteristics in the real icing environment. For example, high fitting speed corresponds to high-altitude low-temperature environment, and low fitting speed corresponds to ground or low-altitude environment. In high-speed airflow, the kinetic energy of water droplets is high, and the liquid water content is positively correlated with the fitting speed, so that the equivalent ice layer thickness can be formed. Higher fitting speed corresponds to smaller cloud and fog water droplet particle size, and lower fitting speed corresponds to larger cloud and fog water droplet particle size. The first set time is shortened under the working condition of higher liquid water content, and the first set time is longer under the working condition of lower liquid water content, so as to ensure that the ice layer thickness reaches a measurable threshold.

[0071] During the experiment, the leading edge of the target blade will grow to a certain size of ice type. After the test is completed, the leading edge icing area range of the target blade can be observed and measured, and the leading edge icing area range is the range of the electric heating assembly. Specifically, multi-angle image acquisition is performed on the leading edge of the target blade, and the icing image of the leading edge is obtained after running for a first set time. For example, multiple industrial cameras are used to collect images of the target blade from the front, side, top, side, bottom, etc. For example, the front can shoot the front icing shape of the leading edge, the side can capture the icing expansion range of the upper wing surface, and the side can capture the icing boundary of the lower wing surface. The image acquisition device can increase the anti-fog coating to reduce the imaging interference of the cloud and fog.

[0072] Then, a three-dimensional scanning technology is used to obtain a three-dimensional model of the icing image, boundary coordinates of the leading edge icing area of the target blade are extracted through modeling, and the icing coverage area and the ice layer thickness are calculated to determine the initial anti-icing area. The initial anti-icing area is the anti-icing area calculated based on the boundary coordinates. However, when setting the electric heating assembly, if the setting is performed according to the boundary coordinates, the cloud and fog parameter may cause the icing area to expand, the target blade to vibrate, or the airflow disturbance may cause the water droplets to impact beyond the expected range, and the edge of the electric heating assembly may have heat loss, etc., which may cause insufficient heating.

[0073] Therefore, it is also necessary to expand the set range of the area along the initial anti-icing area to obtain the leading edge icing area range. Among them, the set range is an expansion range obtained through experiments or experience, so that the heating range of the electric heating assembly can be fully covered. For example, the expansion can be performed along the length direction of the target blade and the direction from the leading edge to the trailing edge, etc. The leading edge icing area range is the final range of the electric heating assembly. Through reasonable expansion, the occurrence of anti-icing blind area can be reduced, and based on the set expansion amount, the energy waste caused by excessive expansion can also be reduced.

[0074] In step 203, the heating power of the electric heating assembly can be gradually reduced by power level from the first power. The first power is an initial high power, which can be set based on an empirical value, and the first power is a safe power without icing, that is, the leading edge of the target blade has no ice particles attached. For each level of heating power, multi-angle image acquisition is performed on the leading edge of the target blade after a second set time. The second set time is the heating time of the electric heating assembly, which can be set in advance according to requirements. For example, different levels of heating power can be set with different second set times, and the high power section melts the ice layer faster, so a shorter second set time can be set. The low and medium power sections need to confirm whether the ice layer is stable, so the second set time can be extended. As an example, the adjustment can be performed in a combination of coarse adjustment and fine adjustment. First, a large step is used to quickly narrow the range, and when the critical value is approached, the step is reduced for fine adjustment.

[0075] If the amount of ice particles attached to the leading edge of the target blade at the second power is less than the first set amount, and the amount of ice particles attached after the set power is reduced is greater than the second set amount, the second power is determined as the anti-icing critical power. The second power is less than the first power, and the first set amount is less than or equal to the second set amount. The first set amount refers to the threshold for determining no icing, and the second set amount refers to the threshold for determining icing. The set power refers to a parameter value set in advance to verify whether the second power is a critical point. When the amount of ice particles attached to the leading edge of the target blade is less than the first set amount, it indicates that there is no icing at present, and the anti-icing is effective. If it is greater than the second set amount after the set power is reduced, it indicates that there is icing, and the anti-icing fails. Therefore, it can be determined that the second power is the anti-icing critical power.

[0076] In addition, in order to ensure test accuracy, the test can be repeated multiple times under the same working condition, and whether the second power is the anti-icing critical power is determined based on the multiple results. For example, if the error of the multiple critical powers is less than the standard error, the average of the anti-icing critical powers of the multiple tests can be taken as the final result.

[0077] In steps 202 and 203, the electric heating assembly is arranged by accurately measuring the icing area range of the leading edge, which saves the arrangement cost of the electric heating assembly and reduces the situation of insufficient anti-icing. By adjusting the heating power of the electric heating assembly, the anti-icing critical power under different working conditions can be accurately found, so that the electric heating anti-icing fan blade can ensure safety and achieve low power consumption under different working conditions, and the operation reliability and life of the fan blade are improved.

[0078] Those skilled in the art can understand that all or part of the functions of various methods in the above embodiments can be realized by hardware or by a computer program. When all or part of the functions in the above embodiments are realized by a computer program, the program can be stored in a computer readable storage medium, which can include a read-only memory, a random access memory, a magnetic disk, an optical disk, a hard disk, and the like. The above functions are realized by executing the program by a computer. For example, the program is stored in a memory of a device, and when the program in the memory is executed by a processor, the above functions are realized. In addition, when all or part of the functions in the above embodiments are realized by a computer program, the program can also be stored in a storage medium such as a server, another computer, a disk, an optical disk, a flash disk, or a mobile hard disk, and is downloaded or copied into a memory of a local device or is updated in version to a system of the local device. When the program in the memory is executed by a processor, all or part of the functions in the above embodiments are realized.

[0079] The above application is described by using specific examples, which is only used to help understand the application and does not limit the application. According to the idea of the application, those skilled in the art can make several simple deductions, modifications, or substitutions.

Claims

1. A method for testing the anti-icing performance of electric heating anti-icing fan blades, characterized in that, include: A single target blade to be tested in the electric heating anti-icing fan blades is fixed on the turntable of the wind tunnel test section by a support and fastening device. The initial installation angle of the target blade is adjusted by controlling the rotation of the turntable so that the target blade matches the installation state of the target blade on the hub. Adjust the wind tunnel parameters of the wind tunnel test section, and conduct anti-icing performance tests on the target blade based on each of the wind tunnel parameters, including incoming wind speed and cloud / fog parameters; The steps of testing the anti-icing performance of the target blade based on each of the wind tunnel parameters include: The set incoming wind speed and the rotational linear velocity of the target blade are combined to obtain the fitted speed of the target blade during operation. The angle of the turntable is adjusted based on the fitted speed so that the airflow direction of the wind tunnel test section matches the airflow angle of the target blade during operation. Based on the fitting speed, the cloud and fog parameters are set, and after running for a first set time, the range of the leading edge icing area of ​​the target blade is measured. An electric heating component is set in the leading edge icing area. The heating power of the electric heating assembly of the target blade is adjusted from high to low, and the anti-icing critical power of the target blade is determined.

2. The anti-icing performance testing method according to claim 1, characterized in that, The target blade includes a blade body and a blade shaft, and the blade shaft includes a first annular surface, a second annular surface, a thread, and a first keyway. The first annular surface is disposed at the first end of the blade shaft, the second annular surface, the thread and the first keyway are disposed at the second end of the blade shaft, and the first end of the blade shaft is close to the blade body.

3. The anti-icing performance testing method according to claim 2, characterized in that, The support and fastening device includes a sleeve, a nut, a load-bearing key, and an end cap; The sleeve includes a sleeve support and a sleeve surface. The inner hole of the sleeve surface is provided with a first inner annular surface and a second inner annular surface. The first inner annular surface matches the first annular surface on the blade stalk shaft of the target blade, and the second inner annular surface matches the second annular surface on the blade stalk shaft of the target blade. The inner thread of the nut matches the thread of the blade shaft, and is used to lock the target blade to the sleeve support. The nut is provided with a plurality of first threaded holes for connection with the end cap. The load-bearing key is built into the first keyway and engages with the second keyway on the inner side of the end cap to restrict the axial swing of the target blade. The end cap is fixed to the sleeve support and matches the plurality of first threaded holes of the nut to achieve locking of the nut and the end cap.

4. The anti-icing performance testing method according to claim 3, characterized in that, The turntable has a circular structure and is provided with evenly distributed second threaded holes. The second threaded holes match the sleeve support base to realize the support and fastening device being fixed to the turntable. The turntable rotates around its own axis and the rotation angle is adjustable.

5. The anti-icing performance testing method according to claim 1, characterized in that, The set incoming air velocity and the rotational linear velocity of the target blade are combined to obtain the fitted velocity of the target blade during operation, including: The incoming wind speed of the wind tunnel test section is obtained, and the incoming wind speed is used to simulate the positive airflow speed experienced by the target blade during operation; The rotational linear velocity of the target blade is calculated based on the reference section rotation radius and actual rotational speed of the target blade. The fitted velocity is calculated using the vector of the incoming wind speed and the linear velocity of rotation through the vector composition rule.

6. The anti-icing performance testing method according to claim 5, characterized in that, The step of calculating the fitted velocity based on the vector of the incoming wind speed and the linear velocity of rotation using a vector composition rule includes: Construct a parallelogram with the first vector corresponding to the incoming wind speed and the second vector corresponding to the rotational linear velocity as adjacent sides; The magnitudes of the velocities are calculated using the Pythagorean theorem from the first and second vectors. The offset angle relative to the incoming wind speed is calculated by using the arctangent function to combine the first vector and the second vector. The fitted velocity is obtained based on the velocity magnitude and the offset angle.

7. The anti-icing performance testing method according to claim 6, characterized in that, The step of adjusting the angle of the turntable based on the fitted velocity to match the airflow direction of the wind tunnel test section with the airflow angle of the target blade during operation includes: Control the rotation of the turntable; When the direction of the leading edge normal of the target blade is detected to match the direction of the offset angle, the rotation of the turntable is stopped.

8. The anti-icing performance testing method according to claim 1, characterized in that, The step of setting the cloud and fog parameters based on the fitted speed and measuring the leading edge icing area of ​​the target blade after running for a first set time includes: Determine cloud and fog parameters that have a mapping relationship with the fitted speed, wherein the cloud and fog parameters include the temperature of the wind tunnel test section, the liquid water content, the cloud and fog droplet size, and the first set time; Multi-angle image acquisition is performed on the leading edge of the target blade, and an icing image of the leading edge is obtained after running for the first set time. A three-dimensional model of the icing image is obtained using three-dimensional scanning technology. The boundary coordinates of the icing area at the leading edge of the target blade are extracted by modeling, and the icing coverage area and ice thickness are calculated to determine the initial anti-icing area. The area extending from the initial anti-icing area to a predetermined range is used to obtain the leading edge icing area range.

9. The anti-icing performance testing method according to claim 1, characterized in that, The process of adjusting the heating power of the electric heating assembly of the target blade from high to low, and determining the anti-icing critical power of the target blade, includes: The heating power of the electric heating component is gradually reduced from the first power level according to the power level; For each heating power level, after running for a second set time, multi-angle image acquisition is performed on the leading edge of the target blade; If the amount of ice particles adhering to the leading edge of the target blade is less than the first set amount of adhering at the second power, and the amount of ice particles adhering after reducing the set power is greater than the second set amount of adhering, then the second power is determined as the anti-icing critical power, the second power is less than the first power, and the first set amount of adhering is less than or equal to the second set amount of adhering.

10. A system for testing the anti-icing performance of electric heating anti-icing fan blades, characterized in that, This includes the target blade, wind tunnel test section, support and fastening device, and controller; The target blade is a single blade to be tested in an electric heating anti-icing fan blade; The wind tunnel test section includes a turntable; The target blade is fixed to the turntable of the wind tunnel test section by the support and fastening device; The controller stores a program that can be loaded by a processor and executed using the anti-icing performance test method as described in any one of claims 1 to 9.

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