Full-size wind turbine blade surface icing experiment method and system
By segmenting and marking blade segments and calculating blade rotation parameters, combined with a full-size wind turbine blade icing experimental system, the problems of large errors and high costs in full-size blade icing experiments were solved, achieving realistic simulation and cost savings.
Patent Information
- Application Number
- CN202511207942.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-27
- Publication Date
- 2025-11-18
AI Technical Summary
Existing technologies make it difficult to conduct dynamic icing experiments on full-size wind turbine blades, resulting in large errors in icing experiments, an inability to realistically simulate the icing state of the blades, and high experimental costs.
A full-size wind turbine blade surface icing experimental system was used. By segmenting and marking the blades, calculating the rotation radius and tip cut-in wind speed of the blade segments, and adjusting the inverter output frequency, an icing experiment was conducted to simulate the working state of the entire impeller and obtain experimental data of the real blades.
It reduces icing experiment errors caused by size effects, lowers experimental costs, achieves realistic simulation of full-size blades, and provides technical support for wind turbine anti-icing research.
Smart Images
Figure CN120969093A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of blade icing experimental technology, and specifically to a method and system for conducting experiments on icing on the surface of a full-size wind turbine blade. Background Technology
[0002] Wind energy, as a natural, pollution-free, and widely applicable clean energy source, is gaining increasing attention and its proportion in my country's total energy mix is rising. Wind energy boasts advantages such as vast reserves, renewability, wide distribution, and zero pollution; however, it also suffers from disadvantages including low density, instability, and significant regional variations. Wind turbines are the best way to convert wind energy into directly usable energy, and designing and developing high-performance wind turbines is of great significance to my country's economic development. Currently, wind turbines are mainly divided into two categories: vertical-axis and horizontal-axis. Compared to vertical-axis wind turbines, horizontal-axis wind turbines have unique advantages. Horizontal-axis wind turbines have a higher tip speed ratio and a higher wind energy utilization coefficient. Horizontal-axis wind turbines are among the most efficient wind energy conversion devices, and performance testing is a necessary condition for wind turbine design.
[0003] Blades are widely used in fluid machinery, aircraft, and aircraft engines. The aerodynamic performance of the blades directly affects the overall efficiency of the fluid machinery. Fluid machinery blades operate in various natural environments; for example, wind turbines are installed outdoors and exposed to sandstorms, rain, snow, freezing rain, and other weather conditions. Over time, or under extreme weather conditions, sludge or ice will inevitably accumulate on the blade surface, leading to reduced blade efficiency, insufficient annual grid-connected power generation, and impacting industrial and agricultural production, resulting in direct economic losses. Therefore, research on the impact of icing on wind turbine surfaces on their performance is urgently needed. Currently, large wind turbines have a rotation diameter of over 100 meters, and individual blades are tens of meters long with a span of hundreds of meters and a chord length of 2 to 3 meters. Therefore, conducting dynamic icing experiments on full-size blades is virtually impossible. Experimental studies on wind turbine blades are typically conducted on scaled-down blades in icing wind tunnels. The aerodynamic performance of blades and other related experiments are studied based on the principle of similarity. However, the effect of size will inevitably introduce errors into the experiment, that is, there will be certain errors compared with the real blade. It is impossible to guarantee the consistency of blade icing with the real blade, and it is impossible to achieve a true simulation of full-size blades. It is also impossible to simulate the effects of high Reynolds numbers and size parameters. If full-size blades are directly used for experiments, the experimental cost will be greatly increased. Therefore, for some experiments that only observe the icing state of the blade surface or carry out anti-icing treatment, a new experimental method can be used to solve the experimental error problem. Summary of the Invention
[0004] To address the aforementioned issues, this invention proposes a method and system for conducting experiments on icing on the surface of full-size wind turbine blades. This method ensures consistency between the icing on the blades and that on real blades, simulates the icing state under full impeller operation, and reduces experimental errors in blade icing caused by size effects.
[0005] The specific technical solution is as follows:
[0006] A full-size wind turbine blade surface icing experimental system includes a wind turbine experimental device and an open jet icing wind tunnel. The wind turbine experimental device includes a drive shaft, a coupling, a motor, a bearing housing, an impeller connected to the drive shaft, a support, and a frequency converter. The impeller is located at the end of the drive shaft, and several blade segments are mounted on the impeller. The outlet of the open jet icing wind tunnel is directly opposite one blade segment, so that the supercooled water from the outlet of the open jet icing wind tunnel hits only one blade. The support is fixed to the ground. The frequency converter is electrically connected to the motor. The motor is connected to the drive shaft through the coupling. The bearing housing is rotatably mounted on the drive shaft through bearings. The bearing housing and the bottom of the motor are fixed to the support. The drive shaft drives the impeller to rotate under the drive of the motor.
[0007] A method for conducting a full-scale wind turbine blade surface icing test based on the aforementioned full-scale wind turbine blade surface icing test system includes the following steps:
[0008] Step 1: Design experimental blades based on the actual blade span and chord length, segment and mark the experimental blades to obtain multiple blade segments, measure each of the multiple blade segments, and measure the rotation radius corresponding to each of the multiple blade segments.
[0009] Step 2: Calculate the tip cut-in wind speed corresponding to each blade segment based on the rotation radius;
[0010] Step 3: Calculate the experimental impeller control speed corresponding to each blade segment based on the blade tip cut-in wind speed;
[0011] Step 4: Adjust the inverter output frequency to the control speed of the experimental impeller to conduct a blade segment icing experiment for each blade segment and obtain real blade experimental data.
[0012] Furthermore, step one includes: taking the span and chord length of the currently used megawatt-class horizontal axis wind turbine blades, designing wind turbine icing test blades based on the span and chord lengths, dividing the test blades into multiple blade segments along the span direction according to experimental needs, and measuring the rotation radius of each blade segment in the impeller.
[0013] Furthermore, step two includes:
[0014] The step of calculating the tip cut-in wind speed corresponding to each blade segment based on the rotation radius includes:
[0015] Calculate the rotational speed of a megawatt-class horizontal axis wind turbine at its rated wind speed;
[0016] Based on the rotational speed, determine the rotational angular velocity of the wind turbine blades;
[0017] Based on the rotational angular velocity and the rotational radius corresponding to each blade segment, the tip cut-in wind speed corresponding to each blade segment is calculated.
[0018] Furthermore, step three includes:
[0019] The step of calculating the experimental impeller control speed corresponding to each blade segment based on the blade tip cut-in wind speed includes:
[0020] Obtain the radius of the experimental impeller;
[0021] Based on the blade tip cut-in wind speed and the experimental impeller radius, the experimental impeller control speed corresponding to each blade segment is calculated.
[0022] Furthermore, step four includes:
[0023] The frequency converter output frequency is adjusted to control the rotational speed of the experimental impeller to conduct icing experiments on each blade segment, obtaining real blade experimental data, including:
[0024] Adjust the inverter output frequency to the control speed of the experimental impeller, turn on the icing wind tunnel, and record the icing morphology characteristics of each blade segment at different time points.
[0025] Furthermore, the freezing time in the leaf segment freezing experiment was an integer multiple of the number of leaves.
[0026] The beneficial effects of this invention are as follows: This invention introduces an icing experiment on real blades without scaling, targeting current large wind turbine blades. Compared with existing technologies, the experimental method of this invention can conduct icing experiments on full-size blades under bounded incoming flow conditions. By preserving the chordal dimension and shape of the full-size wind turbine blade, the blade is divided into several blade segments along the blade's span direction. These segments are then installed on the impeller in batches. Based on the tip inrush velocity of each blade segment under real operating conditions, the corresponding experimental impeller control speed for each blade segment is calculated. The inverter output frequency is adjusted to the experimental impeller control speed, and the icing experiment is conducted to obtain experimental data on the real blade. In addition, since each blade segment has the same tip inrush velocity as the blades of a real wind turbine, considering the full-size blade dimensions, only one blade is tested at a time. That is, the supercooled water at the outlet of the entire open jet icing wind tunnel only impacts one blade rotating to the wind tunnel outlet. Considering that real blades are continuously exposed to air in reality, the experimental time is an integer multiple of the number of blades, thus simulating the icing state under the working conditions of the entire impeller. Therefore, this method greatly reduces the size of the experimental setup, saves experimental costs, and increases the operability of icing experiments on full-size blades, thereby achieving a realistic simulation of full-size blades, reducing the icing experiment error caused by the size effect, and more realistically reflecting the icing situation of blades, providing technical support for wind turbine anti-icing research. Attached Figure Description
[0027] Appendix Figure 1 This is a schematic diagram of the structure of a full-size wind turbine blade surface icing experimental system according to the present invention;
[0028] Appendix Figure 2 This is a schematic diagram of the open jet ice wind tunnel and blade segment structure of the present invention;
[0029] Among them, 1. Impeller; 2. Drive shaft; 3. Bearing housing; 4. Coupling; 5. Motor; 6. Frequency converter; 7. Support; 8. Open jet ice wind tunnel; 9. Blade segment. Detailed Implementation
[0030] To better explain and facilitate understanding of the present invention, the technical solution and effects of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0031] like Figures 1-2As shown, this embodiment provides a full-size wind turbine blade surface icing experimental system, including a wind turbine experimental device and an open jet icing wind tunnel 8; the wind turbine experimental device includes a drive shaft 2, a coupling 4, a motor 5, a bearing housing 3, an impeller 1 connected to the drive shaft 2, a support 7, and a frequency converter 6; the impeller 1 is located at the end of the drive shaft 2, and three blade segments 9 are installed on the impeller 1. The outlet of the open jet icing wind tunnel 8 is directly opposite one blade segment 9, so that the A-direction supercooled water from the outlet of the open jet icing wind tunnel 8 only hits the blade segment 9 directly opposite the outlet of the open jet icing wind tunnel 8. The open jet icing wind tunnel 8 is implemented using existing technology. The support 7 is fixed to the ground. The frequency converter 6 is electrically connected to the motor 5. The motor 5 is connected to the drive shaft 2 through the coupling 4. The bearing housing 3 is rotatably sleeved on the drive shaft 2 through bearings. The bearing housing 3 and the bottom of the motor 5 are fixed on the support 7, which provides support. The drive shaft 2 can drive the impeller 1 to rotate under the drive of the motor 5, thereby driving the blade segment 9 to rotate.
[0032] A method for testing surface icing on a full-size wind turbine blade using the above-mentioned experimental system includes the following steps:
[0033] Step 1: Design the experimental blade based on the actual blade span and chord length, segment and mark the experimental blade to obtain multiple blade segments 9, measure each of the multiple blade segments 9, and measure the rotation radius Rn corresponding to each blade segment in the multiple blade segments 9.
[0034] Based on the span and chord length of currently used megawatt-class horizontal axis wind turbine blades, a wind turbine icing test blade is designed according to its span and chord length dimensions. The chord length variation along the span direction of the test blade is the same as that of the real blade, that is, the cross-sectional dimensions of the blade are the same as those of the real blade. According to the experimental needs, the test blade is divided into multiple equal blade segments 9 along the span direction, and the rotation radius R1, R2, R3, ..., Rn of each blade segment 9 in the impeller is measured.
[0035] Step 2: Calculate the tip cut-in wind speed Vn corresponding to each blade segment 9 based on the rotation radius Rn;
[0036] Calculate the rotational speed N of the megawatt-class wind turbine at its rated wind speed. Based on the rotational speed N, determine the rotational angular velocity ω of the wind turbine blades. Based on the rotational angular velocity ω and the rotational radius Rn corresponding to each blade segment 9, calculate the tip cut-in wind speed Vn corresponding to each blade segment 9, i.e., Vn=ω×Rn, which is used as the tip cut-in wind speed for the experiment of blade segment 9.
[0037] Step 3: Calculate the experimental impeller control speed n* for each blade segment 9 based on the tip cut-in wind speed Vn;
[0038] This includes obtaining the experimental impeller radius R*, and calculating the experimental impeller control speed n* for each blade segment 9 based on the tip cut-in wind speed Vn and the experimental impeller radius R*. Since blade segment 9 is equally divided along its span, the experimental impeller radius R* remains constant. Therefore, the experimental impeller control speed for different blade segments 9 is n* = Vn × R*.
[0039] Step 4: Adjust the output frequency of inverter 6 to the control speed n* of the experimental impeller, so as to conduct an icing experiment on each blade segment 9 and obtain real blade experimental data.
[0040] Specifically, the process involves installing blade segment 9, starting from the blade root segment, onto the experimental hub; adjusting the output frequency of the frequency converter 6 to the control speed n* of the experimental impeller; opening the open jet icing wind tunnel 8; and recording the icing morphology and characteristics of each blade segment 9 at different time points, according to the experimental requirements. All duration experiments are completed, experimental data are recorded, and real blade experimental data are obtained. The icing time for blade segment 9 is an integer multiple of the number of blades.
[0041] The scope of protection of this application is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope and spirit of this application. If such modifications and variations fall within the scope of this application and its equivalents, then the intent of this application also includes these modifications and variations.
Claims
1. A full-size wind turbine blade surface icing experimental system, characterized in that, The system includes a wind turbine experimental setup and an open jet ice tunnel. The wind turbine experimental setup includes a drive shaft, coupling, motor, bearing housing, impeller connected to the drive shaft, support, and frequency converter. The impeller is located at the end of the drive shaft and has multiple blade segments mounted on it. The outlet of the open jet ice tunnel faces one blade segment. The support is fixed to the ground. The frequency converter is electrically connected to the motor. The motor is connected to the drive shaft via the coupling. The bearing housing is rotatably mounted on the drive shaft via bearings. The bearing housing and the bottom of the motor are fixed to the support. The drive shaft drives the impeller to rotate under the drive of the motor.
2. A method for conducting an experiment on the surface icing of a full-size wind turbine blade based on the full-size wind turbine blade surface icing experimental system described in claim 1, characterized in that, Includes the following steps: Step 1: Design experimental blades based on the actual blade span and chord length, segment and mark the experimental blades to obtain multiple blade segments, measure each of the multiple blade segments, and measure the rotation radius corresponding to each of the multiple blade segments. Step 2: Calculate the tip cut-in wind speed corresponding to each blade segment based on the rotation radius; Step 3: Calculate the experimental impeller control speed corresponding to each blade segment based on the blade tip cut-in wind speed; Step 4: Adjust the inverter output frequency to the control speed of the experimental impeller to conduct a blade segment icing experiment for each blade segment and obtain real blade experimental data.
3. The experimental method for icing on the surface of a full-size wind turbine blade according to claim 2, characterized in that, Step one includes: taking the span and chord length of the currently used megawatt-class horizontal axis wind turbine blades, designing wind turbine icing test blades based on the span and chord lengths, dividing the test blades into multiple blade segments along the span direction according to experimental needs, and measuring the rotation radius of each blade segment in the impeller.
4. The experimental method for icing on the surface of a full-size wind turbine blade according to claim 3, characterized in that, Step two includes: The step of calculating the tip cut-in wind speed corresponding to each blade segment based on the rotation radius includes: Calculate the rotational speed of a megawatt-class horizontal axis wind turbine at its rated wind speed; Based on the rotational speed, determine the rotational angular velocity of the wind turbine blades; Based on the rotational angular velocity and the rotational radius corresponding to each blade segment, the tip cut-in wind speed corresponding to each blade segment is calculated.
5. The experimental method for icing on the surface of a full-size wind turbine blade according to claim 4, characterized in that, Step three includes: The step of calculating the experimental impeller control speed corresponding to each blade segment based on the blade tip cut-in wind speed includes: Obtain the radius of the experimental impeller; Based on the blade tip cut-in wind speed and the experimental impeller radius, the experimental impeller control speed corresponding to each blade segment is calculated.
6. The experimental method for icing on the surface of a full-size wind turbine blade according to claim 5, characterized in that, Step four includes: The frequency converter output frequency is adjusted to control the rotational speed of the experimental impeller to conduct icing experiments on each blade segment, obtaining real blade experimental data, including: Adjust the inverter output frequency to the control speed of the experimental impeller, turn on the icing wind tunnel, and record the icing morphology characteristics of each blade segment at different time points.
7. A method for testing icing on the surface of a full-size wind turbine blade according to claim 2 or 6, characterized in that, The freezing time in the leaf segment freezing experiment is an integer multiple of the number of leaves.