Method and apparatus for calculating icing range on wind turbine blade, device, and storage medium

Abstract

A method for calculating an icing range on a wind turbine blade. The method comprises: establishing a gas-liquid two-phase flow calculation model for a wind turbine blade, to obtain a water droplet collision coefficient for each unit on the surface of the wind turbine blade, and subsequently calculating the mass of liquid water captured from the air by each unit; on the basis of a thermal balance equation, calculating a water droplet freezing coefficient for each unit; on the basis of the mass of the liquid water and the water droplet freezing coefficient, calculating a water film thickness, and, performing a force analysis of the water film to obtain a water film flow velocity of each unit; and on the basis of the water film flow velocity and the water film thickness, calculating an inflow water volume and an outflow water volume, and updating the water film thickness for each unit until the difference in water film thickness for each unit before and after the update meets an error requirement, then outputting a final freezing coefficient and an icing thickness for each unit, and, on the basis of the freezing coefficient and the icing thickness for each unit, drawing an icing range distribution map for the surface of the wind turbine blade. Further comprised are an apparatus for calculating an icing range on a wind turbine blade, an electronic device, and a computer-readable storage medium. The method enables accurate acquisition of the icing range on wind turbine blades formed under different operating conditions, thereby improving the efficiency of wind turbine blade deicing.

Description

A fan blade icing range calculation method, device, equipment and storage medium

[0001] The present application claims priority to the Chinese patent application No. 202411031231.9, filed on July 30, 2024, and entitled "A fan blade icing range calculation method, device, equipment and storage medium", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of wind power generation simulation, in particular to a fan blade icing range calculation method, device, equipment and storage medium. BACKGROUND

[0003] In recent years, wind power generation has become one of the important components of global renewable energy. From the development trend, wind power generation technology is constantly improving and innovating, such as increasing the height of the fan, improving the efficiency of the fan, reducing the cost, and providing reliable safety, etc. Statistics show that icing is one of the main problems faced by wind power generation, causing huge losses every year.

[0004] In order to study the prevention method of wind turbine blade icing, a large number of studies are carried out on the formation mechanism and influence characteristics of wind turbine blade icing. Wind turbine blade icing mainly occurs on the leading edge, mainly caused by the collision and freezing of supercooled water droplets in the air. The icing range and shape of the wind turbine blade surface are obviously different under different wind speeds, temperatures and water droplet median diameters. The wind turbine icing protection system is usually divided into two categories: anti-icing and de-icing. The purpose of anti-icing is to prevent the formation and existence of ice layer on the surface of the object, while de-icing means that a small amount of icing is allowed to occur before the de-icing system is started. Based on various principles, the main methods are: 1) using waterproof, anti-icing and black paint; 2) active shutdown, which actively stops the wind turbine before the icing event occurs, so as to minimize icing in order to enable the wind turbine to be started quickly after the icing event ends; 3) hot air technology, which uses the hollow structure inside the blade to heat the air at the blade root and blow it to the tip of the blade that needs protection, so as to achieve the purpose of wind turbine anti-icing and de-icing; 4) electromagnetic pulse technology. Using a set of rear capacitors to discharge to the electromagnetic coil installed below the metal skin of the wind turbine blade, so as to form an electromagnetic eddy current field on the metal skin and generate a transient electromagnetic force, which causes the skin to vibrate rapidly and makes the ice layer deform, thereby breaking and falling off; 5) ultrasonic and low-frequency vibration technology, based on the weak shear strength of the ice layer at the contact surface with the blade, the piezoelectric coupling technology is used to excite ultrasonic waves and generate a wave speed difference at the contact surface, thereby forming a differential shear stress slightly larger than the maximum adhesion stress of the ice layer, and finally achieving the purpose of destroying the adhesion of the ice layer and the blade; 6) electric heating de-icing method, the electric heating anti-icing and de-icing method uses electric energy to directly heat the ice layer on the outer surface of the wind turbine blade, so that a small amount of melted ice layer inside can be separated under the action of aerodynamic force and inertia.

[0005] Compared with the anti-icing strategy, the active de-icing method is usually more effective in implementation. Most of the above wind turbine blade de-icing methods need to design and arrange related devices according to the icing position of the blade, and the position and rate of ice growth mainly depend on the capture of supercooled water droplets in the air, water film flow and freezing process during the operation of the wind turbine blade. In order to fully exert the maximum effect of various de-icing methods, it is crucial to accurately obtain the icing range of the wind turbine blade surface. SUMMARY

[0006] The present application provides a wind turbine blade icing range calculation method, device, equipment and storage medium, which is used to accurately obtain the icing range of the wind turbine blade under different working conditions, so as to improve the de-icing efficiency of the wind turbine blade.

[0007] Therefore, the first aspect of the present application provides a wind turbine blade icing range calculation method, comprising:

[0008] S1. Establish a gas-liquid two-phase flow calculation model for the wind turbine blades based on the finite element method, calculate the external airflow velocity of the wind turbine blades based on the gas-liquid two-phase flow calculation model, and obtain the water droplet collision coefficient of each unit on the surface of the wind turbine blades based on the external airflow velocity.

[0009] S2. Calculate the mass of liquid water in the air captured by each unit on the surface of the fan blades based on the water droplet collision coefficient.

[0010] S3. Calculate the water droplet freezing coefficient of each unit on the surface of the fan blade under water film flow conditions based on the heat balance equation.

[0011] S4. Calculate the water film thickness of each unit on the surface of the wind turbine blade based on the liquid water mass and the water droplet freezing coefficient of each unit, and perform a force analysis on the water film based on the water film thickness of each unit to obtain the water film flow velocity of each unit.

[0012] S5. Calculate the inflow and outflow of water for each unit based on the water film flow rate and water film thickness of each unit, and update the water film thickness of each unit.

[0013] S6. Calculate the difference in water film thickness between each unit before and after the update. If the difference in water film thickness does not meet the error requirements, update the inflow and outflow of water in each unit and return to step S3. If the difference in water film thickness meets the error requirements, output the final freezing coefficient and icing thickness of each unit, and draw the icing range distribution map of the wind turbine blade surface based on the freezing coefficient and icing thickness of each unit.

[0014] Optionally, the method further includes:

[0015] The airflow shear stress of each unit on the surface of the wind turbine blades is obtained based on the external airflow velocity.

[0016] The stress 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:

[0017] The water film is subjected to stress analysis based on the water film thickness and airflow shear stress of each unit to obtain the water film flow velocity of each unit.

[0018] Optionally, the formula for calculating the water film flow velocity is:

[0019] In the formula, Let be the components of the water film flow velocity in the x, y, and z directions, respectively, where μ is the dynamic viscosity of water, and h is the velocity. m Where is the water film thickness, P is the surface pressure of the fan blades, and g is the pressure. i ρ represents the component of gravity in the direction i, where i = x, y; wis the density of water, τ ai is the component of the air flow shear stress in the i direction.

[0020] Optionally, the formula for calculating the liquid water mass is: M0=β 1j wVS j dt

[0021] In the formula, M0is the liquid water mass in the air captured by the fan blade surface unit j, β 1j is the water droplet collision coefficient of the fan blade surface unit j; w is the liquid water content in the air, V is the wind speed, S j is the area of the fan blade surface unit j, and dt is the time step.

[0022] Optionally, the calculation of the water film thickness of each unit of the fan blade surface according to the liquid water mass of each unit and the water droplet freezing coefficient comprises:

[0023] calculating the ice mass formed by freezing in each unit according to the water droplet freezing coefficient of each unit and the liquid water mass in the air captured by each unit;

[0024] calculating the difference between the liquid water mass in the air captured by each unit and the ice mass formed by freezing in each unit;

[0025] calculating the water film thickness of each unit according to the difference of each unit, the water density, and the area of each unit.

[0026] Optionally, 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 )

[0027] In the formula, Q c is the heat loss of convective heat transfer; Q e is the heat taken away by evaporated water; Q w is the heat consumed by the fan blade surface to heat the captured water droplets from the ambient temperature T to the water film temperature T w ; Q rQ is the heat loss for long-wave radiation; Q m Q is the heat energy converted from kinetic energy after water droplets collide with unit j; Q f M is the latent heat released after the water film freezes into ice; M f M is the ice mass formed by freezing in unit j; M in M0 is the water mass flowing into unit j of the fan blade surface; β 1j β is the water droplet collision coefficient of unit j of the fan blade surface; β 3j V is the freezing coefficient of unit j; V is the wind speed; w is the liquid water content in the air; S j S is the area of unit j of the fan blade surface; L f C is the latent heat of ice melting; C w Cp is the specific heat of water.

[0028] The second aspect of the present application provides a fan blade icing range calculation device, comprising:

[0029] A first calculation unit is configured to establish a gas-liquid two-phase flow calculation model of the fan blade according to the finite element method, calculate the external airflow speed of the fan blade based on the gas-liquid two-phase flow calculation model, and obtain the water droplet collision coefficient of each unit on the surface of the fan blade according to the external airflow speed;

[0030] A second calculation unit is configured to calculate the liquid water mass captured by each unit on the surface of the fan blade according to the water droplet collision coefficient;

[0031] A third calculation unit is configured to calculate the water droplet freezing coefficient of each unit on the surface of the fan blade under the water film flow condition according to a heat balance equation;

[0032] An analysis unit is configured 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 perform force analysis on the water film based on the water film thickness of each unit to obtain the water film flow speed of each unit;

[0033] An updating unit is configured to calculate the inflow water mass and the outflow water mass of each unit according to the water film flow speed and the water film thickness of each unit, and update the water film thickness of each unit;

[0034] A fourth calculation unit is configured to calculate the water film thickness difference of each unit before and after updating, update the inflow water mass and the outflow water mass of each unit if the water film thickness difference does not meet the error requirement, and trigger the third calculation unit; if the water film thickness difference meets the error requirement, output the final freezing coefficient and the ice thickness of each unit, and draw an icing range distribution map of the surface of the fan blade according to the freezing coefficient and the ice thickness of each unit.

[0035] Optionally, the first calculation unit is further configured to:

[0036] According to the external airflow velocity, the airflow shear stress of each unit on the fan blade surface is obtained;

[0037] The analysis unit is specifically configured to calculate the water film thickness of each unit on the fan blade surface according to the liquid water mass and the water droplet freezing coefficient of each unit, and perform stress 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.

[0038] The third aspect of the present application provides an electronic device, the device comprising a processor and a memory;

[0039] The memory is configured to store program code and transmit the program code to the processor;

[0040] The processor is configured to execute the fan blade icing range calculation method according to the instructions in the program code.

[0041] The fourth aspect of the present application provides a computer readable storage medium for storing program code, the program code being executed by a processor to implement the fan blade icing range calculation method of any one of the first aspect.

[0042] From the above technical solutions, the present application has the following advantages:

[0043] The application provides a fan blade icing range calculation method, comprising the following steps: S1, establishing a gas-liquid two-phase flow calculation model of a fan blade according to a finite element method, calculating an external airflow velocity of the fan blade based on the gas-liquid two-phase flow calculation model, and obtaining water droplet collision coefficients of each unit on the surface of the fan blade according to the external airflow velocity; S2, calculating liquid water mass captured by each unit on the surface of the fan blade in the air according to the water droplet collision coefficients; S3, calculating water droplet freezing coefficients of each unit on the surface of the fan blade under water film flow conditions according to a heat balance equation; S4, calculating water film thicknesses of each unit on the surface of the fan blade according to the liquid water mass and the water droplet freezing coefficients of each unit, performing force analysis on the water film based on the water film thicknesses of each unit, and obtaining water film flow velocities of each unit; S5, calculating inflow water mass and outflow water mass of each unit according to the water film flow velocities and the water film thicknesses of each unit, and updating the water film thicknesses of each unit; S6, calculating water film thickness difference of each unit before and after updating, if the water film thickness difference does not meet error requirements, updating the inflow water mass and the outflow water mass of each unit, and returning to step S3; if the water film thickness difference meets the error requirements, outputting final freezing coefficients and icing thicknesses of each unit, and drawing an icing range distribution map of the surface of the fan blade according to the freezing coefficients and the icing thicknesses of each unit. The application simultaneously considers water droplet collision and water film flow processes, can accurately obtain an icing range of the fan blade under different working conditions, and is helpful to improve fan blade deicing efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0045] Fig. 1 is a flowchart of a fan blade icing range calculation method provided by an embodiment of the present application;

[0046] Fig. 2 is a force analysis diagram of a water film on the surface of a fan blade provided by an embodiment of the present application;

[0047] Fig. 3 is a schematic diagram of heat balance on the surface of a fan blade provided by an embodiment of the present application;

[0048] Fig. 4 is a schematic diagram of calculation results of an icing range on the surface of a fan blade provided by an embodiment of the present application;

[0049] Fig. 5 is a flowchart of a fan blade icing range calculation process provided by an embodiment of the present application;

[0050] Fig. 6 is a structural schematic diagram of a fan blade icing range calculation device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order for those skilled in the art to better understand the technical scheme of the present application, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0052] For the convenience of understanding, please refer to FIG. 1, the present application embodiment provides a kind of fan blade icing range calculation method, comprising:

[0053] S1, the gas-liquid two-phase flow calculation model of fan blade is established according to finite element method, the external airflow velocity of fan blade is calculated based on gas-liquid two-phase flow calculation model, and the water droplet collision coefficient of each unit on the surface of fan blade is obtained according to external airflow velocity.

[0054] The gas-liquid two-phase flow calculation model of fan blade is established according to finite element method, the external airflow velocity of fan blade is calculated based on gas-liquid two-phase flow calculation model, and the external airflow velocity of fan blade is obtained. Specifically, based on the environmental parameter data such as two-dimensional section coordinate point, area and wind speed of fan blade, the external airflow field of fan blade of wind turbine can be solved according to the basic principle of boundary element method, which includes the distribution of external airflow velocity of blade. Then, based on the initialized water droplet and external airflow velocity, the force state of water droplet is determined by Lagrange algorithm; please refer to FIG. 2, according to the force state of water droplet, the motion trajectory of water droplet is tracked, when water droplet collides with the surface of fan blade, the collision position and collision velocity of water droplet are determined; according to the normal vector of collision position and collision velocity, and external airflow velocity, the water droplet collision coefficient β of each unit on the surface of fan blade is obtained by combining water droplet local collision coefficient calculation formula. 1j .

[0055] Further, the airflow shear stress τ of each unit on the surface of fan blade can also be obtained according to external airflow velocity a , wherein the airflow shear stress τ of blade surface is the product of airflow gradient along the normal direction of blade and dynamic viscosity of fluid (dynamic viscosity of fluid is constant). a

[0056] S2, the liquid water mass in air captured by each unit on the surface of fan blade is calculated according to water droplet collision coefficient.

[0057] The liquid water mass M0 in air captured by each unit on the surface of fan blade is calculated according to water droplet collision coefficient of each unit on the surface of fan blade, and the calculation formula is: M0= β 1j wVS j ​dt

[0058] wherein M0is the liquid water mass captured by the fan blade surface unit j in the air, β 1j is the water droplet collision coefficient of the fan blade surface unit j; w is the liquid water content in the air, with the unit of kg / m 3 ; V is the wind speed, with the unit of m / s; S j is the area of the fan blade surface unit j, with the unit of m 2 ; and dt is the time step, with the unit of s.

[0059] S3, calculating the water droplet freezing coefficient of each unit of the fan blade surface under the water film flow condition according to the heat balance equation.

[0060] Please refer to FIG. 3, the water droplet freezing coefficient of each unit of the fan blade surface under the water film flow condition is calculated according to the heat balance equation, wherein 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 )

[0061] wherein Q c is the heat loss of the convection heat transfer; Q e is the heat taken away by the evaporated water; Q w is the heat consumed by the fan blade surface for heating the captured water droplet from the ambient temperature T to the water film temperature T w ; Q r is the heat loss of the long-wave radiation; Q m is the heat energy converted from the kinetic energy after the water droplet collides into the unit j; Q f is the latent heat released after the water film freezes into ice; M f is the ice mass formed by the freezing in the unit j; M in is the water mass flowing into the unit j; M0is the liquid water mass captured by the fan blade surface unit j in the air; β 1j is the water droplet collision coefficient of the fan blade surface unit j; β 3j is the freezing coefficient of the unit j; V is the wind speed; w is the liquid water content in the air; Sj is the area of the fan blade surface unit j; L f is the latent heat of ice melting; C w is the specific heat of water. By solving the above formulas, the freezing coefficient β of each unit of the fan blade surface can be obtained 3j .

[0062] S4, calculating the water film thickness of each unit of the fan blade surface according to the liquid water mass of each unit and the water droplet freezing coefficient, and performing force analysis on the water film based on the water film thickness of each unit to obtain the water film flow speed of each unit.

[0063] According to the water droplet freezing coefficient of each unit and the liquid water mass in the air captured by each unit, the ice mass formed by freezing in each unit is calculated; the difference between the liquid water mass in the air captured by each unit and the ice mass formed by freezing in each unit is calculated to obtain the residual water amount of each unit; and the water film thickness of each unit is calculated according to the difference of each unit, the water density and the area of each unit, that is:

[0064] In the formula, h m is the water film thickness, ρ w is the density of water, with a unit of kg / m 3 , and the value is 1000 kg / m 3 .

[0065] Based on the water film thickness of each unit and the air flow shear stress, force analysis is performed on the water film to obtain the water film flow speed of each unit The calculation formula of the water film flow speed is as follows:

[0066] In the formula, u , u , and u

[0067] are respectively the components of the water film flow speed in the x, y and z directions, μ is the dynamic viscosity of water, and the preferred value is 1.781×10 -3 Pa·s; P is the pressure of the fan blade surface, with a unit of Pa; g i represents the component of gravity in the i direction, with a unit of m / s 2 , i=x,y; ρ w is the density of water, and τ ai is the component of the air flow shear stress in the i direction.

[0068] According to the water film flow speed u(u x ,u y ,u z) and water film thickness h m The inflow water quantity and the outflow water quantity of each unit are calculated, and the water film thickness of each unit is updated. The inflow water quantity and the outflow water quantity can be calculated according to the direction and size of the airflow shear force, in combination with mass balance.

[0069] S6, the water film thickness difference of each unit before and after updating is calculated, if the water film thickness difference does not meet the error requirement, the inflow water quantity and the outflow water quantity of each unit are updated, and step S3 is returned; if the water film thickness difference meets the error requirement, the final freezing coefficient and the ice thickness of each unit are output, and the ice range distribution diagram of the fan blade surface is drawn according to the freezing coefficient and the ice thickness of each unit.

[0070] The difference between the water film thickness (h m ) t of each unit before updating and the water film thickness (h m ) t+dt of each unit after updating, if the water film thickness difference (h m ) t -(h m ) t+dt | of each unit before and after updating is greater than ε, ε is an error, the inflow water quantity and the outflow water quantity of each unit are updated, and step S3 is returned for iterative calculation; if the water film thickness difference (h m ) t -(h m ) t+dt | of each unit before and after updating is less than or equal to ε, the iterative calculation is ended, the final freezing coefficient and the ice thickness of each unit are output, and the ice range distribution diagram of the fan blade surface is drawn according to the freezing coefficient and the ice thickness of each unit, please refer to FIG. 4 and FIG. 5. It should be noted that the value of ε can be set according to the actual situation, and the specific value of ε is not limited herein.

[0071] The present application simultaneously considers the water droplet collision and the water film flow process, and can accurately obtain the ice range generated by the fan blade under different working conditions such as different wind speeds and different water droplet particle sizes, which is helpful to improve the ice removal efficiency of the fan blade.

[0072] The above is one embodiment of the fan blade ice range calculation method provided by the present application, and the following is one embodiment of the fan blade ice range calculation device provided by the present application.

[0073] Please refer to FIG. 6, the fan blade ice range calculation device provided by the embodiment of the present application, comprising:

[0074] The first calculation unit is configured to establish a gas-liquid two-phase flow calculation model of 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 element on the surface of the fan blade according to the external airflow velocity.

[0075] The second calculation unit is configured to calculate a liquid water mass captured by each element on the surface of the fan blade according to the water droplet collision coefficient.

[0076] The third calculation unit is configured to calculate a water droplet freezing coefficient of each element on the surface of the fan blade under a water film flow condition according to a heat balance equation.

[0077] The analysis unit is configured to calculate a water film thickness of each element on the surface of the fan blade according to the liquid water mass and the water droplet freezing coefficient of each element, and perform force analysis on the water film based on the water film thickness of each element to obtain a water film flow velocity of each element.

[0078] The updating unit is configured to calculate inflow water quantity and outflow water quantity of each element according to the water film flow velocity and the water film thickness of each element, and update the water film thickness of each element.

[0079] The fourth calculation unit is configured to calculate a water film thickness difference of each element before and after updating, update the inflow water quantity and the outflow water quantity of each element if the water film thickness difference does not meet an error requirement, and trigger the third calculation unit, and output a final freezing coefficient and an icing thickness of each element if the water film thickness difference meets the error requirement, and draw an icing range distribution map of the surface of the fan blade according to the freezing coefficient and the icing thickness of each element.

[0080] As a further improvement, the first calculation unit is further configured to:

[0081] obtain an airflow shear stress of each element on the surface of the fan blade according to the external airflow velocity;

[0082] The analysis unit is specifically configured to calculate a water film thickness of each element on the surface of the fan blade according to the liquid water mass and the water droplet freezing coefficient of each element, and perform force analysis on the water film based on the water film thickness and the airflow shear stress of each element to obtain a water film flow velocity of each element.

[0083] The embodiment of the application further provides an electronic device, which comprises a processor and a memory;

[0084] The memory is configured to store program code and transmit the program code to the processor;

[0085] The processor is configured to execute the fan blade icing range calculation method in the foregoing method embodiment according to instructions in the program code.

[0086] The embodiment of the present application further provides a computer readable storage medium, which is used for storing program codes, and the program codes are executed by a processor to implement the fan blade icing range calculation method in the foregoing method embodiment.

[0087] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiment, which will not be repeated here.

[0088] The terms "first", "second", "third", "fourth" and the like (if any) in the specification of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0089] It should be understood that, in the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can represent three cases of only A, only B and A and B existing at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b or c can represent a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b and c can be single or multiple.

[0090] In several embodiments provided in the present 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 only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed objects can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0091] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may be distributed on multiple network units. Part or all of the units may be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0092] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0093] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for executing all or part of the steps of the method described in each embodiment of the present application by a computer device (which can be a personal computer, a server, or a network device, etc.). The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (English full name: Read-Only Memory, English abbreviation: ROM), a random access memory (English full name: Random Access Memory, English abbreviation: RAM), a magnetic disk or an optical disk, and various program code storage media.

[0094] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of calculating an icing range of a wind turbine blade, characterized by, The method comprises the following steps: S1, a gas-liquid two-phase flow calculation model of a fan blade is established according to a finite element method, an external airflow velocity of the fan blade is calculated based on the gas-liquid two-phase flow calculation model, and a water droplet collision coefficient of each unit on a surface of the fan blade is obtained according to the external airflow velocity; S2, a liquid water mass captured by each unit on the surface of the fan blade is calculated according to the water droplet collision coefficient; S3, a water droplet freezing coefficient of each unit on the surface of the fan blade under a water film flow condition is calculated according to a heat balance equation; S4, a water film thickness of each unit on the surface of the fan blade is calculated according to the liquid water mass and the water droplet freezing coefficient of each unit, a force analysis is performed on the water film based on the water film thickness of each unit, and a water film flow velocity of each unit is obtained; S5, an inflow water mass and an outflow water mass of each unit are calculated according to the water film flow velocity and the water film thickness of each unit, and the water film thickness of each unit is updated; S6, a water film thickness difference of each unit before and after the update is calculated, if the water film thickness difference does not meet an error requirement, the inflow water mass and the outflow water mass of each unit are updated, and the step S3 is returned to; if the water film thickness difference meets the error requirement, a final freezing coefficient and an ice thickness of each unit are output, and an ice coverage distribution map of the surface of the fan blade is drawn according to the freezing coefficient and the ice thickness of each unit.

2. The method of claim 1, wherein, The method further comprises the following steps: a gas flow shear stress of each unit on the surface of the fan blade is obtained according to the external airflow velocity; the force analysis performed on the water film based on the water film thickness of each unit to obtain the water film flow velocity of each unit comprises the following steps: the force analysis performed on the water film based on the water film thickness and the gas flow shear stress of each unit to obtain the water film flow velocity of each unit.

3. The method of claim 2, wherein, The calculation formula of the water film flow speed is: In the formulae, respectively, μ is the dynamic viscosity of water, h m is the water film thickness, P is the pressure on the surface of the fan blade, g i denotes the component of the gravitational force in the i direction, i = x, y; p w is the density of water, τ ai is the component of the air flow shear stress in the i direction.

4. The method of claim 1, wherein, The calculation formula of the liquid water mass is: M0=β 1j wVS j dt where M0is the mass of liquid water in the air captured by the fan blade surface element j, β 1j is the droplet collision coefficient for the fan blade surface element j; w is the liquid water content in the air, V is the wind speed, S j is the area of the fan blade surface element j, and dt is the time step.

5. The method of claim 1, wherein, the calculation of 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 comprises the following steps: an ice mass formed by freezing in each unit is calculated according to the water droplet freezing coefficient of each unit and the liquid water mass captured by air in each unit; a difference between the liquid water mass captured by air in each unit and the ice mass formed by freezing in each unit is calculated; the water film thickness of each unit is calculated according to the difference, a water density and an area of each unit.

6. The method of claim 1, wherein, 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 lost to convective heat transfer; Q e is the heat removed by evaporating water; Q w is the heat consumed to heat the water droplets captured from the environment temperature T to the water film temperature T w at the fan blade surface; Q r is the heat lost to long wave radiation; Q m is the heat energy converted from kinetic energy after water droplets collide to the unit j; Q f is the latent heat released after the water film freezes to ice; M f is the ice mass formed by freezing within the unit j; M in is the water mass flowing into the unit j; M0is the liquid water mass in the air captured by the fan blade surface unit j; β 1j is the water droplet collision coefficient of the fan blade surface unit j; β 3j is the freezing coefficient of the 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 melting latent heat of ice; C w is the specific heat of water.

7. A device for calculating the icing range of wind turbine blades, characterized in that, The method comprises the following steps: a first calculation unit is configured to establish a gas-liquid two-phase flow calculation model of a 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 a surface of the fan blade according to the external airflow velocity; a second calculation unit is configured to calculate a liquid water mass captured by each unit on the surface of the fan blade according to the water droplet collision coefficient; a third calculation unit is configured to calculate a water droplet freezing coefficient of each unit on the surface of the fan blade under a water film flow condition according to a heat balance equation; an analysis unit is configured to calculate a 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, 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. The updating unit is configured to calculate inflow water quantity and outflow water quantity of each unit according to the water film flow velocity and the water film thickness of each unit, and update the water film thickness of each unit; The fourth calculating unit is configured to calculate the water film thickness difference of each unit before and after updating, and if the water film thickness difference does not meet the error requirement, update the inflow water quantity and the outflow water quantity of each unit, and trigger the third calculating unit; if the water film thickness difference meets the error requirement, output the final freezing coefficient and the ice thickness of each unit, and draw the ice distribution diagram of the fan blade surface according to the freezing coefficient and the ice thickness of each unit.

8. The device for calculating an icing range of a fan blade according to claim 7, characterized by, The first calculating unit is further configured to: obtain the air flow shear stress of each unit on the fan blade surface according to the external air flow velocity; The analysis unit is specifically configured to calculate the water film thickness of each unit on the fan blade surface according to 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 air flow shear stress of each unit to obtain the water film flow velocity of each unit.

9. An electronic device, comprising: The device comprises a processor and a memory; The memory is configured to store program code and transmit the program code to the processor; The processor is configured to execute the method according to any one of claims 1-6 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium is configured to store program code, and the program code is executed by the processor to realize the method according to any one of claims 1-6.

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