A design method of deicing system based on icing characteristics of wind turbine blades

Abstract

This invention discloses a design method for an anti-icing and de-icing system based on the icing characteristics of wind turbine blades, belonging to the field of wind power generation technology. Based on the regularity of icing occurrence and growth in the chordal and spanwise directions of the blades, and the potential failure of anti-icing coatings in severely icing areas under severe freezing weather conditions, combined with blade icing tests and a database of spatiotemporal icing development characteristics, this invention proposes a highly efficient anti-icing and de-icing system design and a highly efficient, low-energy-consumption operation control method that combines an active electrothermal film de-icing method with a passive anti-icing coating method. This enables wind turbines to operate continuously without blade icing in all climates. This invention fully integrates the advantages of electrothermal de-icing technology and anti-icing coating technology, enabling wind turbine blades to have highly efficient anti-icing and de-icing functions under all climate conditions, and features low system energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of wind power generation technology, specifically relating to a design method for an anti-icing and de-icing system based on the icing characteristics of wind turbine blades. Background Technology

[0002] In wind farms located in low-wind-speed areas and some high-wind-speed areas in the south, severe icing problems are common in winter and spring. Icing on wind turbine blades alters the aerodynamic shape and weight distribution of the blades, disrupts the load balance, and leads to problems such as blade and rotor vibration, directly impacting the economic efficiency and safety of unit operation and power generation.

[0003] Given the large existing stock of wind power, there is an urgent need for efficient anti-icing and de-icing technologies for wind turbine blades during freezing weather. Currently, anti-icing and de-icing methods include gas-thermal / electro-thermal de-icing based on thermal melting of ice, chemical de-icing, mechanical de-icing, and anti-icing coating methods based on superhydrophobic coating spraying.

[0004] Currently, there is no widely applicable and mature anti-icing technology (or combination) for wind turbine blades. In fact, due to the differences in the environment and climate where wind turbines are located, coupled with the characteristics of wind turbine blades such as large length and uneven thickness distribution, anti-icing technologies suffer from risks such as high energy consumption, short lifespan, high equipment and maintenance costs, and lightning damage to varying degrees, creating a "bottleneck" for blade anti-icing methods based on a single technology approach. Furthermore, due to the long dimensions of the blades in the chord direction, especially the spanwise direction, and the different relative velocities between the blades and the atmospheric flow at different positions / regions along the spanwise direction, the process of water vapor or tiny water droplets in the atmosphere interacting with the blades to form icing exhibits certain patterns and differences. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a design method for an anti-icing and de-icing system based on the icing characteristics of wind turbine blades. This method can effectively meet the anti-icing and de-icing needs of blades under different degrees of freezing weather, and is highly efficient and energy-saving in de-icing.

[0006] This invention is achieved through the following technical solution:

[0007] A design method for an anti-icing and de-icing system based on the icing characteristics of wind turbine blades includes the following steps:

[0008] S1: Collect and analyze the environmental and meteorological factors of wind turbine units to determine the combination of meteorological parameters for the blade icing characteristic test;

[0009] S2: Based on the actual blade condition of wind turbine units, recreate and fabricate a test model of blade icing characteristics coated with an anti-icing coating;

[0010] S3: In the wind tunnel test facility, based on the meteorological parameter combination determined in S1 and the blade icing characteristic test model obtained in S2, combined with the normal operating parameters of the wind turbine, the icing environment characteristics of the wind turbine blade are restored; the icing characteristics of the blade icing characteristic test model are observed to obtain the spatiotemporal characteristics of icing on the blade surface.

[0011] S4: Quantitatively analyze the spatiotemporal characteristics of icing on the blade surface obtained in S3 to obtain the evolution law of icing on the blade in different time periods after the start of icing formation, and obtain an icing law database.

[0012] S5: Based on the icing pattern database obtained from S5, for blades that cannot be prevented from icing by using an anti-icing coating alone, an electric heating film is added for auxiliary thermal de-icing.

[0013] S6: Determine the areas on the blades where electric heating films need to be installed, and based on the differences in icing intensity in each area, customize the rated power of the electric heating films in different areas to complete the design of the blade anti-icing and de-icing system.

[0014] Preferably, in S1, the environmental and meteorological factors include wind speed, air pressure, air temperature, humidity, and the particle size distribution of supercooled water droplets in the air.

[0015] Preferably, in S1, the combination of meteorological parameters includes the main meteorological characteristics that can reflect the normal icing weather and extreme freezing weather conditions in which the wind turbine is located.

[0016] Preferably, in S2, the blade condition includes surface material, airfoil, length, and surface roughness.

[0017] Preferably, in S2, the suction and pressure surfaces of the blade icing characteristic test model are uniformly sprayed with an anti-icing coating, and the process and spraying parameters of the anti-icing coating are consistent with those of the actual wind turbine blades.

[0018] Preferably, in S3, the icing characteristics include the type of leaf icing, the area of ​​occurrence, and the rate of formation.

[0019] Preferably, in S4, the evolution of blade icing includes the development of icing area and icing thickness.

[0020] Preferably, in S5, blades that cannot be de-iced by using an anti-icing coating alone are judged according to the following principle: if an area with an ice thickness of more than 2 mm appears within 30 minutes under extreme weather conditions, the anti-icing coating in that area is considered to be ineffective.

[0021] Preferably, when constructing the actual wind turbine blades, the electric heating film is first laid, and then the entire outer surface of the blades is sprayed with an anti-icing coating.

[0022] More preferably, the thickness of the anti-icing coating is 0.3 to 0.5 mm.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] This invention discloses a design method for an anti-icing and de-icing system based on the icing characteristics of wind turbine blades. Based on the regularity of icing occurrence and growth in the chordal and spanwise directions of the blades, and the potential failure of anti-icing coatings in severely icing areas under severe freezing weather conditions, and combined with blade icing tests and a database of spatiotemporal icing development characteristics, this invention proposes a highly efficient anti-icing and de-icing system design and a highly efficient, low-energy-consumption operation control method that combines an active electrothermal film de-icing method with a passive anti-icing coating method. This enables wind turbines to operate continuously without blade icing in all climates. This invention fully integrates the advantages of electrothermal de-icing technology and anti-icing coating technology, enabling wind turbine blades to have highly efficient anti-icing and de-icing functions under all climate conditions (including extreme freezing weather). Furthermore, by combining icing monitoring and a blade icing characteristic database, the operating power of the motor thermal film in each area of ​​the blade is optimized, reducing the overall energy consumption of the anti-icing and de-icing system. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. These descriptions are intended to explain the invention and not to limit it.

[0027] like Figure 1 The present invention relates to a design method for an anti-icing and de-icing system based on the icing characteristics of wind turbine blades. First, for the specific wind turbine blades to which the anti-icing and de-icing scheme is to be designed, environmental and meteorological factors (including but not limited to wind speed, air pressure, temperature, humidity, and the distribution of supercooled water droplet particle size in the air) are collected and organized. Combined with extreme weather conditions under which the wind turbine blades experience the most severe freezing, multiple sets of parameter combinations are selected and designed for blade icing characteristic testing. The selection and design of the meteorological parameter combinations must reflect the main meteorological characteristics under normal icing weather and severe (extreme) freezing weather conditions.

[0028] Secondly, based on the blade condition of the target wind turbine for anti-icing and de-icing modification (such as surface material, airfoil, length, surface roughness, etc.), the same blade icing test model was reproduced and made.

[0029] Crucially, the suction and pressure surfaces of the above-mentioned test model were uniformly and completely sprayed with an anti-icing coating, and the process and spraying parameters (such as thickness) were consistent with the modification requirements for spraying a superhydrophobic anti-icing coating on the blades.

[0030] Then, in the wind tunnel test facility, based on the above meteorological data settings and test blade design, combined with the normal operation of the wind turbine (such as speed), the icing environment characteristics of the wind turbine blades are reproduced.

[0031] By observing the icing characteristics of wind turbine blades under various icing climate conditions, including the type, occurrence area, and formation rate of blade icing, the spatiotemporal characteristics of icing on the blade surface are obtained, namely, the characteristics of icing occurrence and development over time.

[0032] Quantitative analysis of the experimental results, combined with existing icing theories, revealed that icing primarily occurs at the blade tip and the leading edge of the middle and rear sections of the blade. This is because the relative velocity between the blade tip and the incoming airflow is higher, causing tiny supercooled water droplets in the air to collide with the faster-moving blade. These supercooled water droplets are more prone to morphological changes, solidifying and adhering to the collision area to form icing. In the middle and rear sections of the blade, icing is more likely to occur at the leading edge due to the initial collision of the airflow with the leading edge. In contrast, icing on other parts of the blade is more likely due to the impact of icing at the leading edge on the overall aerodynamic shape of the blade, leading to the gradual spread and growth of the ice layer.

[0033] Quantitative analysis was conducted on the temporal and spatial development characteristics of icing on the blade surface. Critical values ​​were set for different blade spanwise locations to indicate when icing would progress to a more severe (or uncontrolled) state. For example, after a specific time, the percentage of the blade surface covered by icing in the chordal direction would reach a certain critical value, or the thickness of icing at a specific location on the blade would exceed a certain value within a specific time period. Once this critical value was exceeded, due to the failure of the blade's aerodynamic characteristics, the blade would quickly become completely covered by the spreading icing.

[0034] Under the above settings, based on the spatiotemporal characteristic analysis results of the experimental data, the evolution law of all blades coated with anti-icing coatings during different time periods after the onset of icing (including the development of icing area and thickness, etc.) is obtained, forming an icing law database. Based on this database, the time when icing occurs at a specific blade location, as well as the evolution of ice thickness over time, can be queried.

[0035] Generally, if the blades are coated, and an area with an ice thickness of more than 2 mm appears within 30 minutes under extreme weather conditions, it can be considered that the anti-icing function of the coating in that area has failed, meaning that anti-icing cannot be achieved based on the anti-icing coating, and an electric heating film is needed for auxiliary thermal de-icing.

[0036] Under this setting, by combining the icing characteristic database, the areas of the entire blade to be added for electric heating de-icing are determined. In addition, by taking into account the differences in icing intensity in different areas under severe icing weather, a customized design is carried out, and the rated power of the electric heating film is selected in a targeted manner to form a design scheme.

[0037] Finally, during the anti-icing and de-icing retrofit construction phase of the target wind turbine blades, according to the above-mentioned electrothermal de-icing system design scheme, the electric heating film is first laid. Then, after the electric heating film is laid, an anti-icing coating is sprayed onto the entire outer surface of the blades. Since the thickness of the electric heating film is generally small, spraying the anti-icing coating onto the surface of the electric heating film does not affect the operation of the electric heating film equipment. The spraying thickness of the anti-icing coating is generally no more than 0.3 to 0.5 mm, and its impact on the conduction of heat energy generated by the electric heating film can be ignored.

[0038] It should be noted that the above description is only a part of the embodiments of the present invention, and all equivalent changes made to the system described in this invention are included within the protection scope of this invention. Those skilled in the art can make similar substitutions to the specific examples described, as long as they do not deviate from the structure of the invention or exceed the scope defined in these claims, all of which fall within the protection scope of this invention.

Claims

1. A design method for an anti-icing and de-icing system based on the icing characteristics of wind turbine blades, characterized in that, Includes the following steps: S1: Collect and analyze the environmental and meteorological factors of wind turbine units to determine the combination of meteorological parameters for the blade icing characteristic test; S2: Based on the actual blade condition of a wind turbine, recreate and fabricate a test model of blade icing characteristics coated with an anti-icing coating; wherein, the suction and pressure surfaces of the test model of blade icing characteristics are uniformly coated with an anti-icing coating, and the process and spraying parameters of the anti-icing coating are consistent with those of the actual wind turbine blade. S3: In the wind tunnel test facility, based on the meteorological parameter combination determined in S1 and the blade icing characteristic test model obtained in S2, combined with the normal operating parameters of the wind turbine, the icing environment characteristics of the wind turbine blade are restored; the icing characteristics of the blade icing characteristic test model are observed to obtain the spatiotemporal characteristics of icing on the blade surface; the icing characteristics include the type, occurrence area and formation rate of blade icing. S4: Quantitatively analyze the spatiotemporal characteristics of icing on the blade surface obtained in S3 to obtain the evolution law of icing on the blade in different time periods after the start of icing formation, and obtain an icing law database. S5: Based on the icing pattern database obtained from S5, for blades that cannot be prevented from icing by using an anti-icing coating alone, an electric heating film is added for auxiliary thermal de-icing; among them, blades that cannot be prevented from icing by using an anti-icing coating alone are judged according to the following principle: under extreme weather conditions, if an area with an ice thickness of more than 2 mm appears within 30 minutes, the anti-icing coating function in that area is considered to be ineffective. S6: Determine the areas on the blades where electric heating films need to be installed, and based on the differences in icing intensity in each area, customize the rated power of the electric heating films in different areas to complete the design of the blade anti-icing and de-icing system.

2. The anti-icing and de-icing system design method based on the icing characteristics of wind turbine blades as described in claim 1, characterized in that, In S1, the environmental and meteorological factors include wind speed, air pressure, air temperature, humidity, and the particle size distribution of supercooled water droplets in the air.

3. The anti-icing and de-icing system design method based on the icing characteristics of wind turbine blades as described in claim 1, characterized in that, In S1, the combination of meteorological parameters includes the main meteorological characteristics that can reflect the normal icing weather and extreme freezing weather in which the wind turbine is located.

4. The anti-icing and de-icing system design method based on the icing characteristics of wind turbine blades as described in claim 1, characterized in that, In S2, the blade condition includes surface material, airfoil, length, and surface roughness.

5. The anti-icing and de-icing system design method based on the icing characteristics of wind turbine blades as described in claim 1, characterized in that, In S4, the evolution of blade icing includes the development of icing area and icing thickness.

6. The anti-icing and de-icing system design method based on the icing characteristics of wind turbine blades as described in claim 1, characterized in that, When constructing actual wind turbine blades, the first step is to lay an electric heating film, and then spray an anti-icing coating on the entire outer surface of the blades.

7. The anti-icing and de-icing system design method based on the icing characteristics of wind turbine blades as described in claim 6, characterized in that, The thickness of the anti-icing coating is 0.3~0.5mm.

Images