Method, device, equipment and storage medium for calculating ice coverage range of wind turbine blades

Abstract

The present application discloses a method, device, equipment, and storage medium for calculating the ice coverage range of fan blades. The method includes: establishing a gas-liquid two-phase flow calculation model for fan blades to obtain the water droplet collision coefficient of each unit on the fan blade surface, and then calculating the mass of liquid water in the air captured by each unit; calculating the water droplet freezing coefficient of each unit based on a heat balance equation; calculating the water film thickness based on the liquid water mass and the water droplet freezing coefficient, and obtaining the water film flow velocity of each unit by performing a force analysis on the water film; calculating the inflow and outflow of water based on the water film flow velocity and water film thickness, and updating the water film thickness of each unit until the difference in water film thickness before and after the update meets the error requirement; outputting the final freezing coefficient and ice coverage thickness of each unit, and drawing a distribution map of the ice coverage range on the fan blade surface based on the freezing coefficient and ice coverage thickness of each unit. This method accurately obtains the range of ice coverage on the fan blade under different operating conditions, thereby improving the deicing efficiency of the fan blades.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation simulation, and in particular to a method, device, equipment and storage medium for calculating the ice coverage range of wind turbine blades. Background Art

[0002] In recent years, wind power has become a vital component of global renewable energy. Wind power technology continues to improve and innovate, with advancements such as increasing turbine height, improving efficiency, reducing costs, and ensuring reliable safety. However, statistics show that icing is a major problem facing wind power generation, resulting in significant losses each year.

[0003] To investigate methods for preventing and controlling icing on wind turbine blades, extensive research has been conducted on the mechanisms and influencing factors of icing on wind turbine blades. Ice on wind turbine blades is primarily concentrated on the leading edge, formed primarily by the collision and freezing of supercooled water droplets in the air. The extent and morphology of ice on wind turbine blades vary significantly under varying wind speeds, temperatures, and median droplet diameters. Wind turbine icing protection systems are generally categorized into two types: anti-icing and de-icing. Anti-icing aims to prevent the formation and persistence of ice on surfaces, while de-icing allows a small amount of ice to accumulate before the de-icing system is activated. Based on various principles, the main approaches include: 1) the use of waterproof, anti-icing, and black coatings; 2) active shutdown, which involves shutting down the wind turbine before an icing event occurs to minimize icing and enable rapid restart after the event. 3) hot air technology, which utilizes the hollow structure within the blades to heat air at the blade root and direct it to the blade tip, where protection is most needed, to prevent and de-ice wind turbines. 4) Electromagnetic pulse technology. A post-capacitor group is used to instantaneously discharge the electromagnetic coil installed under the metal skin of the wind turbine blade, thereby forming an electromagnetic eddy current field on the metal skin and generating a transient electromagnetic force. This electromagnetic force causes the skin to vibrate rapidly and causes the ice layer to deform, thereby breaking and falling off. 5) Ultrasonic and low-frequency vibration technology. Based on the weak shear strength of the contact surface between the ice layer and the blade, piezoelectric coupling technology is used to excite ultrasonic waves and generate a wave velocity difference at the contact surface, thereby forming a differential shear stress slightly greater than the maximum adhesion stress of the ice, and ultimately achieving the purpose of destroying the adhesion between the ice layer and the blade. 6) Electric heating deicing method. The electric heating anti-icing and deicing method uses electrical energy to directly heat the ice layer on the outer surface of the wind turbine blade, so that the small amount of melted ice layer inside can be detached under the action of aerodynamic force and inertia.

[0004] Active de-icing methods are generally much more effective than anti-icing strategies. Most of the aforementioned wind turbine blade de-icing methods require device design and placement tailored to the location of ice on the blades. The location and rate of ice growth are primarily determined by the capture, film flow, and freezing of supercooled air droplets during blade operation. To maximize the effectiveness of these de-icing methods, efficiently and accurately determining the extent of ice on the wind blade surface is crucial. Summary of the Invention

[0005] The present application provides a method, device, equipment and storage medium for calculating the ice coverage range of fan blades, which are used to accurately obtain the range of ice coverage on fan blades under different working conditions to improve the deicing efficiency of fan blades.

[0006] In view of this, a first aspect of the present application provides a method for calculating the ice coverage range of wind turbine blades, comprising:

[0007] S1. Establishing a gas-liquid two-phase flow calculation model for a fan blade according to the finite element method, calculating the external airflow velocity of the fan blade based on the gas-liquid two-phase flow calculation model, and obtaining the water droplet collision coefficient of each unit on the surface of the fan blade according to the external airflow velocity;

[0008] S2. calculating the mass of liquid water in the air captured by each unit on the surface of the fan blade according to the water droplet collision coefficient;

[0009] S3. Calculate the water drop freezing coefficient of each unit on the fan blade surface under water film flow conditions based on the heat balance equation;

[0010] S4. Calculating the water film thickness of each unit on the surface of the fan blade according to the mass of the liquid water in each unit and the water droplet freezing coefficient, performing a force analysis on the water film based on the water film thickness of each unit, and obtaining the water film flow velocity of each unit;

[0011] S5. Calculating the inflow and outflow of each unit according to the water film flow velocity and the water film thickness of each unit, and updating the water film thickness of each unit;

[0012] S6. Calculate the difference in water film thickness of each unit before and after the update. If the water film thickness difference does not meet the error requirement, update the water inflow and outflow of each unit and return to step S3. If the water film thickness difference meets the error requirement, output the final freezing coefficient and ice thickness of each unit, and draw an ice coverage range distribution map on the wind turbine blade surface based on the freezing coefficient and ice thickness of each unit.

[0013] Optionally, the method further includes:

[0014] Obtaining the airflow shear stress of each unit on the surface of the fan blade according to the external airflow velocity;

[0015] The force analysis of the water film based on the water film thickness of each unit to obtain the water film flow velocity of each unit includes:

[0016] The force analysis of the water film is performed based on the water film thickness of each unit and the airflow shear stress to obtain the water film flow velocity of each unit.

[0017] Optionally, the calculation formula for the water film flow velocity is:

[0018]

[0019] Where, are the components of the water film flow velocity in the x, y, and z directions, μ is the dynamic viscosity of water, and h m is the water film thickness, P is the surface pressure of the fan blade, g i represents the component of gravity in the i direction, i = x, y; ρ w is the density of water, τ ai is the component of the airflow shear stress in the i direction.

[0020] Optionally, the calculation formula for the liquid water mass is:

[0021] M0=β 1j wV j dt

[0022] Where M0 is the mass of liquid water in the air captured by unit j on the surface of the fan blade, β 1j is the water droplet collision coefficient of unit j on the fan blade surface; w is the liquid water content in the air, V is the wind speed, S j is the area of ​​unit j on the surface of the fan blade, and dt is the time step.

[0023] Optionally, the calculating the water film thickness of each unit on the surface of the fan blade according to the liquid water mass and the water droplet freezing coefficient of each unit includes:

[0024] Calculating the mass of ice formed by freezing in each unit according to the water drop freezing coefficient of each unit and the mass of liquid water in the air captured by each unit;

[0025] Calculate the difference between the mass of liquid water in the air captured by each cell and the mass of ice formed by freezing in each cell;

[0026] The water film thickness of each cell is calculated based on the difference value of each cell, the water density and the area of ​​each cell.

[0027] Optionally, the heat balance equation is:

[0028] Q c +Qe +Q w +Q r =Q m +Q f

[0029] Q w =S j β 1j V W w (T w -T)

[0030] Q f =β 3j (M0+M in )L f

[0031] M f =β 3j (M0+M in )

[0032] Where Q c is the heat loss due to convection heat transfer; Q e The heat taken away by evaporating water; Q w Heat the captured water droplets on the wind blade surface from the ambient temperature T to the water film temperature T w Calories consumed; Q r is the heat lost due to long-wave radiation; Q m Q is the heat energy converted from kinetic energy after the water droplet collides with unit j; f M is the latent heat released after the water film freezes into ice; f is the mass of ice formed by freezing in unit j; M in is the amount of water flowing into unit j by the water film; M0 is the mass of liquid water in the air captured by unit j on the surface of the fan blade; β 1j is the water droplet collision coefficient of unit j on the fan blade surface; β 3j is the freezing coefficient of unit j; V is the wind speed; w is the liquid water content in the air; S j is the area of ​​the fan blade surface unit j; L f is the latent heat of melting of ice; C w is the specific heat of water.

[0033] A second aspect of the present application provides a device for calculating the ice coverage range of wind turbine blades, comprising:

[0034] a first calculation unit, configured to establish a gas-liquid two-phase flow calculation model for the fan blade according to a finite element method, calculate an external airflow velocity of the fan blade based on the gas-liquid two-phase flow calculation model, and obtain a water droplet collision coefficient of each unit on the surface of the fan blade according to the external airflow velocity;

[0035] a second calculation unit, configured to calculate the mass of liquid water in the air captured by each unit on the surface of the fan blade according to the water droplet collision coefficient;

[0036] The third calculation unit is used to calculate the water drop freezing coefficient of each unit on the surface of the fan blade under the water film flow condition according to the heat balance equation;

[0037] an analysis unit, configured to calculate the water film thickness of each unit on the surface of the fan blade according to the mass of the liquid water and the water droplet freezing coefficient of each unit, perform a force analysis on the water film based on the water film thickness of each unit, and obtain a water film flow velocity of each unit;

[0038] an updating unit, configured to calculate the inflow and outflow of each unit according to the water film flow velocity and the water film thickness of each unit, and to update the water film thickness of each unit;

[0039] The fourth calculation unit is used to calculate the difference in water film thickness of each unit before and after the update. If the water film thickness difference does not meet the error requirement, the water inflow and outflow of each unit are updated, and the third calculation unit is triggered; if the water film thickness difference meets the error requirement, the final freezing coefficient and ice thickness of each unit are output, and a distribution map of the ice coverage range on the surface of the wind turbine blade is drawn according to the freezing coefficient and ice thickness of each unit.

[0040] Optionally, the first computing unit is further configured to:

[0041] Obtaining the airflow shear stress of each unit on the surface of the fan blade according to the external airflow velocity;

[0042] The analysis unit is specifically used to calculate the water film thickness of each unit on the surface of the fan blade based on the liquid water mass and the water droplet freezing coefficient of each unit, and perform force analysis on the water film based on the water film thickness and the airflow shear stress of each unit to obtain the water film flow velocity of each unit.

[0043] A third aspect of the present application provides an electronic device, the device comprising a processor and a memory;

[0044] The memory is used to store program code and transmit the program code to the processor;

[0045] The processor is used to execute the wind turbine blade ice coverage range calculation method described in any one of the first aspects according to the instructions in the program code.

[0046] A fourth aspect of the present application provides a computer-readable storage medium for storing program code, wherein the program code, when executed by a processor, implements the method for calculating the ice coverage range of wind turbine blades according to any one of the first aspects.

[0047] It can be seen from the above technical solutions that this application has the following advantages:

[0048] The present application provides a method for calculating the ice coverage range of fan blades, including: S1, establishing a gas-liquid two-phase flow calculation model of the fan blades according to the finite element method, calculating the external airflow velocity of the fan blades based on the gas-liquid two-phase flow calculation model, and obtaining the water droplet collision coefficient of each unit on the fan blade surface according to the external airflow velocity; S2, calculating the mass of liquid water in the air captured by each unit on the fan blade surface according to the water droplet collision coefficient; S3, calculating the water droplet freezing coefficient of each unit on the fan blade surface under water film flow conditions according to the heat balance equation; S4, calculating the water droplet freezing coefficient of each unit on the fan blade surface according to the liquid water mass and the water droplet freezing coefficient of each unit. Film thickness, based on the water film thickness of each unit, the force analysis of the water film is performed to obtain the water film flow velocity of each unit; S5, the inflow and outflow of each unit are calculated according to the water film flow velocity and water film thickness of each unit, and the water film thickness of each unit is updated; S6, the difference in water film thickness of each unit before and after the update is calculated. If the difference in water film thickness does not meet the error requirement, the inflow and outflow of each unit are updated, and the step S3 is returned; if the difference in water film thickness meets the error requirement, the final freezing coefficient and ice thickness of each unit are output, and the ice coverage range distribution map of the fan blade surface is drawn according to the freezing coefficient and ice thickness of each unit. This application takes into account both the water drop collision and the water film flow process, and can accurately obtain the range of ice coverage on the fan blades under different working conditions, which helps to improve the de-icing efficiency of the fan blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 A flow chart of a method for calculating the ice coverage range of wind turbine blades provided in an embodiment of the present application;

[0051] Figure 2 A force analysis diagram of a water film on a fan blade surface provided in an embodiment of the present application;

[0052] Figure 3 A schematic diagram of heat balance on the surface of a fan blade provided in an embodiment of the present application;

[0053] Figure 4 A schematic diagram of calculation results of ice coverage on a wind turbine blade surface provided in an embodiment of the present application;

[0054] Figure 5 A schematic flow chart of a process for calculating the ice coverage range of a wind turbine blade provided in an embodiment of the present application;

[0055] Figure 6 A structural schematic diagram of a device for calculating the ice coverage range of wind turbine blades provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0057] For easier understanding, please refer to Figure 1 , an embodiment of the present application provides a method for calculating the ice coverage range of wind turbine blades, comprising:

[0058] S1. A gas-liquid two-phase flow calculation model for fan blades is established based on the finite element method. The external airflow velocity of the fan blades is calculated based on the gas-liquid two-phase flow calculation model. The water droplet collision coefficient of each unit on the fan blade surface is obtained according to the external airflow velocity.

[0059] Based on the finite element method, a gas-liquid two-phase flow calculation model for the fan blade is established. Based on the gas-liquid two-phase flow calculation model, the external flow field distribution of the fan blade is calculated to obtain the external airflow velocity of the fan blade. Specifically, based on the environmental parameter data such as the coordinate points, area and wind speed of the fan blade's two-dimensional cross-section, the basic principles of the boundary element method can be used to solve the external airflow field of the wind turbine fan blade. The airflow field includes the external airflow velocity distribution of the blade. Then, based on the initialized water droplets and external airflow velocity, the Lagrangian algorithm is used to determine the force state of the water droplets; please refer to Figure 2 According to the force state of the water droplet, the motion trajectory of the water droplet is tracked. When the water droplet collides with the surface of the fan blade, the collision position and collision speed of the water droplet are determined. According to the collision speed, the normal vector of the collision position and the external airflow speed, combined with the calculation formula of the water droplet local collision coefficient, the water droplet collision coefficient β of each unit on the fan blade surface is obtained. 1j .

[0060] Furthermore, the airflow shear stress τ of each unit on the fan blade surface can be obtained according to the external airflow velocity: a , where the airflow shear force τ on the blade surface is a It is the product of the airflow gradient along the blade normal and the dynamic viscosity of the fluid (the dynamic viscosity of the fluid is a constant).

[0061] S2. Calculate the mass of liquid water in the air captured by each unit on the surface of the fan blade based on the water droplet collision coefficient.

[0062] The mass of liquid water M0 in the air captured by each unit on the surface of the fan blade is calculated based on the water droplet collision coefficient of each unit on the surface of the fan blade. The calculation formula is:

[0063] M0=β 1j wV j dt

[0064] Where M0 is the mass of liquid water in the air captured by unit j on the surface of the fan blade, β 1j is the water droplet collision coefficient of unit j on the fan blade surface; w is the liquid water content in the air, unit is kg / m 3 ; V is wind speed, unit is m / s; S j is the area of ​​the fan blade surface unit j, in m 2 ; dt is the time step, in seconds.

[0065] S3. Calculate the water drop freezing coefficient of each unit on the fan blade surface under water film flow conditions based on the heat balance equation.

[0066] Please refer to Figure 3 , the water drop freezing coefficient of each unit on the fan blade surface under water film flow conditions is calculated according to the heat balance equation, where the heat balance equation is:

[0067] Q c +Q e +Q w +Q r =Q m +Q f

[0068] Q w =S j β 1j V W w (T w -T)

[0069] Q f =β 3j (M0+M in )L f

[0070] M f =β 3j (M0+M in )

[0071] Where Q c is the heat loss due to convection heat transfer; Q e The heat taken away by evaporating water; Q wHeat the captured water droplets on the wind blade surface from the ambient temperature T to the water film temperature T w Calories consumed; Q r is the heat lost due to long-wave radiation; Q m Q is the heat energy converted from kinetic energy after the water droplet collides with unit j; f M is the latent heat released after the water film freezes into ice; f is the mass of ice formed by freezing in unit j; M in is the amount of water flowing into unit j by the water film; M0 is the mass of liquid water in the air captured by unit j on the surface of the fan blade; β 1j is the water droplet collision coefficient of unit j on the fan blade surface; β 3j is the freezing coefficient of unit j; V is the wind speed; w is the liquid water content in the air; S j is the area of ​​the fan blade surface unit j; L f is the latent heat of melting of ice; C w is the specific heat of water. By combining the above formulas, the freezing coefficient β of each unit on the surface of the fan blade can be obtained. 3j .

[0072] S4. Calculate the water film thickness of each unit on the fan blade surface based on the liquid water mass and the water droplet freezing coefficient of each unit, perform a force analysis on the water film based on the water film thickness of each unit, and obtain the water film flow velocity of each unit.

[0073] The mass of ice formed by freezing in each unit is calculated based on the water drop freezing coefficient of each unit and the mass of liquid water in the air captured by each unit. The difference between the mass of liquid water in the air captured by each unit and the mass of ice formed by freezing in each unit is calculated to obtain the residual water volume of each unit. The water film thickness of each unit is calculated based on the difference, water density and area of ​​each unit, that is:

[0074]

[0075] Where h m is the water film thickness, ρ w is the density of water in kg / m 3 , the value is 1000kg / m 3 .

[0076] The water film flow velocity of each unit is obtained by analyzing the water film thickness and air flow shear stress of each unit. Water film flow velocity The calculation formula is:

[0077]

[0078] Where, are the components of the water film flow velocity in the x, y, and z directions, respectively. μ is the dynamic viscosity of water, and its preferred value is 1.781×10 -3 Pa·s; P is the surface pressure of the fan blade, unit is Pa; g i Represents the component of gravity in the i direction, in m / s 2 , i=x,y;ρ w is the density of water, τ ai is the component of the airflow shear stress in the i direction.

[0079] S5. Calculate the inflow and outflow of each unit according to the water film flow velocity and water film thickness of each unit, and update the water film thickness of each unit.

[0080] According to the water film flow velocity u(u x ,u y ,u z ) and water film thickness h m The inflow and outflow of each unit are calculated, and the water film thickness of each unit is updated. The inflow and outflow of water can be calculated based on the direction and magnitude of the air flow shear force and combined with mass balance.

[0081] S6. Calculate the difference in water film thickness of each unit before and after the update. If the water film thickness difference does not meet the error requirement, update the water inflow and outflow of each unit and return to step S3. If the water film thickness difference meets the error requirement, output the final freezing coefficient and ice thickness of each unit, and draw an ice coverage range distribution map on the wind turbine blade surface based on the freezing coefficient and ice thickness of each unit.

[0082] Calculate the water film thickness of each unit before updating (h m ) t The water film thickness of each unit after update (h m ) t+dt If the water film thickness difference of each unit before and after the update|(h m ) t -(h m ) t+dt |>ε, ε is the error, then update the water inflow and outflow of each unit, and return to step S3 for iterative calculation; if the water film thickness difference of each unit before and after the update |(h m ) t -(h m ) t+dt |≤ε, the iterative calculation ends, and the final freezing coefficient and ice thickness of each unit are output. The ice coverage range distribution map of the wind turbine blade surface is drawn based on the freezing coefficient and ice thickness of each unit. For details, please refer to Figure 4 and Figure 5It should be noted that the value of ε can be set according to actual conditions, and its specific value is not limited here.

[0083] This application takes into account both the water droplet collision and water film flow processes, and can accurately obtain the range of ice formation on wind blades under different working conditions such as different wind speeds and different water droplet particle sizes, which helps to improve the de-icing efficiency of wind blades.

[0084] The above is an embodiment of a method for calculating the ice coverage range of a wind turbine blade provided by the present application. The following is an embodiment of a device for calculating the ice coverage range of a wind turbine blade provided by the present application.

[0085] Please refer to Figure 6 , an embodiment of the present application provides a device for calculating ice coverage of wind turbine blades, comprising:

[0086] a first calculation unit, configured to establish a gas-liquid two-phase flow calculation model for the fan blade according to the finite element method, calculate an external airflow velocity of the fan blade based on the gas-liquid two-phase flow calculation model, and obtain a water droplet collision coefficient of each unit on the surface of the fan blade according to the external airflow velocity;

[0087] a second calculation unit, for calculating the mass of liquid water in the air captured by each unit on the surface of the fan blade according to the water droplet collision coefficient;

[0088] The third calculation unit is used to calculate the water drop freezing coefficient of each unit on the surface of the fan blade under the water film flow condition according to the heat balance equation;

[0089] An analysis unit is used to calculate the water film thickness of each unit on the fan blade surface based on the liquid water mass and the water droplet freezing coefficient of each unit, perform a force analysis on the water film based on the water film thickness of each unit, and obtain the water film flow velocity of each unit;

[0090] An updating unit is used to calculate the inflow and outflow of each unit according to the water film flow velocity and water film thickness of each unit, and to update the water film thickness of each unit;

[0091] The fourth calculation unit is used to calculate the difference in water film thickness of each unit before and after the update. If the water film thickness difference does not meet the error requirement, the water inflow and outflow of each unit are updated, and the third calculation unit is triggered; if the water film thickness difference meets the error requirement, the final freezing coefficient and ice thickness of each unit are output, and the ice coverage range distribution map of the wind turbine blade surface is drawn according to the freezing coefficient and ice thickness of each unit.

[0092] As a further improvement, the first computing unit is further configured to:

[0093] Obtain the airflow shear stress of each unit on the surface of the fan blade according to the external airflow velocity;

[0094] The analysis unit is specifically used to calculate the water film thickness of each unit on the surface of the fan blade according to the liquid water mass and the water droplet freezing coefficient of each unit, and to perform force analysis on the water film based on the water film thickness and airflow shear stress of each unit to obtain the water film flow velocity of each unit.

[0095] An embodiment of the present application further provides an electronic device, the device including a processor and a memory;

[0096] The memory is used to store program codes and transmit the program codes to the processor;

[0097] The processor is configured to execute the wind turbine blade ice coverage calculation method in the aforementioned method embodiment according to instructions in the program code.

[0098] An embodiment of the present application further provides a computer-readable storage medium for storing program code. When the program code is executed by a processor, the method for calculating the ice coverage range of wind turbine blades in the aforementioned method embodiment is implemented.

[0099] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0100] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0101] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0102] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0103] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0104] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0105] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for executing all or part of the steps of the method described in each embodiment of the present application through a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (English full name: Read-Only Memory, English abbreviation: ROM), random access memory (English full name: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program code.

[0106] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for calculating the ice coverage of wind turbine blades, characterized in that: include: S1. Establishing a gas-liquid two-phase flow calculation model for a fan blade according to the finite element method, calculating the external airflow velocity of the fan blade based on the gas-liquid two-phase flow calculation model, and obtaining the water droplet collision coefficient of each unit on the surface of the fan blade according to the external airflow velocity; S2. calculating the mass of liquid water in the air captured by each unit on the surface of the fan blade according to the water droplet collision coefficient; S3. Calculate the water drop freezing coefficient of each unit on the fan blade surface under water film flow conditions based on the heat balance equation; S4. Calculating the water film thickness of each unit on the surface of the fan blade according to the mass of the liquid water in each unit and the water droplet freezing coefficient, performing a force analysis on the water film based on the water film thickness of each unit, and obtaining the water film flow velocity of each unit; S5. Calculating the inflow and outflow of each unit according to the water film flow velocity and the water film thickness of each unit, and updating the water film thickness of each unit; S6. Calculate the difference in water film thickness of each unit before and after the update. If the water film thickness difference does not meet the error requirement, update the water inflow and outflow of each unit and return to step S3. If the water film thickness difference meets the error requirement, output the final freezing coefficient and ice thickness of each unit, and draw an ice coverage range distribution map on the wind turbine blade surface based on the freezing coefficient and ice thickness of each unit.

2. The method for calculating the ice coverage of wind turbine blades according to claim 1, characterized in that: The method further comprises: Obtaining the airflow shear stress of each unit on the surface of the fan blade according to the external airflow velocity; The force analysis of the water film based on the water film thickness of each unit to obtain the water film flow velocity of each unit includes: The force analysis of the water film is performed based on the water film thickness of each unit and the airflow shear stress to obtain the water film flow velocity of each unit.

3. The method for calculating the ice coverage of wind turbine blades according to claim 2, characterized in that: The calculation formula of the water film flow velocity is: Where, are the components of the water film flow velocity in the x, y, and z directions, μ is the dynamic viscosity of water, and h m is the water film thickness, P is the surface pressure of the fan blade, g i represents the component of gravity in the i direction, i = x, y; ρ w is the density of water, τ ai is the component of the airflow shear stress in the i direction.

4. The method for calculating the ice coverage of wind turbine blades according to claim 1, characterized in that: The calculation formula of the liquid water mass is: M0=β 1j wVS j dt Where M0 is the mass of liquid water in the air captured by unit j on the surface of the fan blade, β 1j is the water droplet collision coefficient of unit j on the fan blade surface; w is the liquid water content in the air, V is the wind speed, S j is the area of ​​unit j on the surface of the fan blade, and dt is the time step.

5. The method for calculating the ice coverage of wind turbine blades according to claim 1, characterized in that: The calculating of the water film thickness of each unit on the surface of the fan blade according to the liquid water mass and the water drop freezing coefficient of each unit includes: Calculating the mass of ice formed by freezing in each unit according to the water drop freezing coefficient of each unit and the mass of liquid water in the air captured by each unit; Calculate the difference between the mass of liquid water in the air captured by each cell and the mass of ice formed by freezing in each cell; The water film thickness of each cell is calculated based on the difference value of each cell, the water density and the area of ​​each cell.

6. The method for calculating the ice coverage of wind turbine blades according to claim 1, characterized in that: The heat balance equation is: Q c +Q e +Q w +Q r =Q m +Q f Q w =S j ·β 1j VwC w (T w -T) Q f =β 3j ·(M0+M in )L f M f =β 3j ·(M0+M in ) Where Q c is the heat loss due to convection heat transfer; Q e The heat taken away by evaporating water; Q w Heat the captured water droplets on the wind blade surface from the ambient temperature T to the water film temperature T w Calories consumed; Q r is the heat lost due to long-wave radiation; Q m Q is the heat energy converted from kinetic energy after the water droplet collides with unit j; f M is the latent heat released after the water film freezes into ice; f is the mass of ice formed by freezing in unit j; M in is the amount of water flowing into unit j by the water film; M0 is the mass of liquid water in the air captured by unit j on the surface of the fan blade; β 1j is the water droplet collision coefficient of unit j on the fan blade surface; β 3j is the freezing coefficient of unit j; V is the wind speed; w is the liquid water content in the air; S j is the area of ​​the fan blade surface unit j; L f is the latent heat of melting of ice; C w is the specific heat of water.

7. A device for calculating the ice coverage range of wind turbine blades, characterized in that: include: a first calculation unit, configured to establish a gas-liquid two-phase flow calculation model for the fan blade according to a finite element method, calculate an external airflow velocity of the fan blade based on the gas-liquid two-phase flow calculation model, and obtain a water droplet collision coefficient of each unit on the surface of the fan blade according to the external airflow velocity; a second calculation unit, configured to calculate the mass of liquid water in the air captured by each unit on the surface of the fan blade according to the water droplet collision coefficient; The third calculation unit is used to calculate the water drop freezing coefficient of each unit on the surface of the fan blade under the water film flow condition according to the heat balance equation; an analysis unit, configured to calculate the water film thickness of each unit on the surface of the fan blade according to the mass of the liquid water and the water droplet freezing coefficient of each unit, perform a force analysis on the water film based on the water film thickness of each unit, and obtain a water film flow velocity of each unit; an updating unit, configured to calculate the inflow and outflow of each unit according to the water film flow velocity and the water film thickness of each unit, and to update the water film thickness of each unit; The fourth calculation unit is used to calculate the difference in water film thickness of each unit before and after the update. If the water film thickness difference does not meet the error requirement, the water inflow and outflow of each unit are updated, and the third calculation unit is triggered; if the water film thickness difference meets the error requirement, the final freezing coefficient and ice thickness of each unit are output, and a distribution map of the ice coverage range on the surface of the wind turbine blade is drawn according to the freezing coefficient and ice thickness of each unit.

8. The wind turbine blade ice coverage calculation device according to claim 7, characterized in that: The first computing unit is further configured to: Obtaining the airflow shear stress of each unit on the surface of the fan blade according to the external airflow velocity; The analysis unit is specifically used to calculate the water film thickness of each unit on the surface of the fan blade based on the liquid water mass and the water droplet freezing coefficient of each unit, and perform force analysis on the water film based on the water film thickness and the airflow shear stress of each unit to obtain the water film flow velocity of each unit.

9. An electronic device, characterized in that: The device includes a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method for calculating the ice coverage range of wind turbine blades according to any one of claims 1 to 6 according to instructions in the program code.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store program codes, and when the program codes are executed by a processor, the method for calculating the ice coverage range of wind turbine blades according to any one of claims 1 to 6 is implemented.

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