Fan blade partition heating and deicing control method

Abstract

The invention provides a fan blade partition heating and deicing control method. The fan blade partition heating and deicing control method comprises the following steps that S1, a fan blade is divided into N heating areas from the front end of the blade to the root of the blade; the length from the front end to the root heating area forms an arithmetic progression; s2, arranging an electric heating strip in each heating area; s3, parameters of the environment where the fan blade is located are obtained, and the driving current for heating and deicing is determined according to the environment parameters of the fan blade; s4, controlling the electric heating strip to work according to the driving current; according to the method, the N regions in the arithmetic progression are formed according to the length of the fan blade from the end part to the root part, and then the layout modes of the heating strips in all the regions are different, so that the fan blade is heated in different ways, and the deicing loss can be prevented from being increased while the deicing effect is effectively ensured.

Description

Technical Field

[0001] The present invention relates to a deicing control method, and in particular to a fan blade zone heating deicing control method. Background Art

[0002] Wind power generation, as a clean, renewable energy source, has been widely used worldwide. However, in cold and humid climates, wind turbine blades are prone to icing, which not only adversely affects the aerodynamic performance of the blades but also poses a threat to the operational stability and safety of the entire wind turbine system.

[0003] Ice on blades changes the aerodynamic shape of the blade surface, reducing the wind turbine's power output efficiency. Furthermore, ice on blades increases their weight, leading to blade imbalance, vibration, increased mechanical stress, and even, in severe cases, causing wind turbine shutdown or equipment failure.

[0004] Existing technologies use heating to de-ice fan blades, rapidly heating the blade surface to achieve de-icing. However, this approach neglects the issue of balanced ice distribution across the blades. Ice accumulation is most severe at the leading edge, with ice thickness decreasing linearly from the tip to the root. Because de-icing power requirements vary at different blade locations, this overall de-icing method cannot guarantee de-icing synchronization. Furthermore, it results in a less uniform temperature distribution across the blade surface, increasing energy consumption.

[0005] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a method for controlling the zoned heating and deicing of fan blades, by forming an arithmetic progression of N zones in the length of the fan blades from the end to the root, and then the layout of the heating strips in each zone is different, thereby forming a localized heating of the fan blades, which can effectively ensure the deicing effect while avoiding increased deicing losses.

[0007] The present invention provides a fan blade zone heating and deicing control method, comprising the following steps:

[0008] S1. The fan blade is divided into N heating zones from the front end of the blade to the root of the blade; and the length of the heating zone from the front end to the root forms an arithmetic progression;

[0009] S2. Provide electric heating strips in each heating zone;

[0010] S3 obtains the parameters of the fan blade environment, and determines the driving current for heating and deicing based on the fan blade environmental parameters;

[0011] S4. Control the operation of the electric heating strip according to the driving current.

[0012] Furthermore, the driving current is determined by the following method:

[0013] Determine the critical de-icing power density:

[0014] q cr =I i 2 R i =q R +q C +q wv ;

[0015] Where: q cr is the de-icing critical power density, I i represents the deicing driving current of the ith partition, R i represents the resistance of the ith partition, q R is the radiation heat loss power, q C is the convective heat loss power, q wv is the power density required for ice melting;

[0016] The de-icing driving current I is obtained from the critical de-icing power density i .

[0017] Furthermore, the radiation heat loss power q R Determined by the following method:

[0018] q R =εσ(T a +273) 3 (TT a );

[0019] Where: ε is the radiation coefficient, σ is the Boltzmann constant, T a is the ambient temperature, and T is the fan blade temperature.

[0020] Furthermore, the convective heat loss power q C Determined by the following method:

[0021] q C =h×(TT a ); where: h is the air convection coefficient; T a is the ambient temperature, and T is the fan blade temperature.

[0022] Furthermore, the air convection coefficient h is determined by the following method:

[0023] h=ρ·c·v rel ·st, where: ρ is the air density, v relis the relative wind speed of air, c is the specific heat capacity of air;

[0024] Intermediate variables Intermediate variables Where l is the chord pitch of the fan blades and η is the air viscosity coefficient.

[0025] Furthermore, the electric heating strip comprises a heat insulating layer, a heating layer, a heat conducting layer and a base layer from top to bottom;

[0026] wherein the base layer is attached to the fan blade and the base layer is epoxy resin;

[0027] The heating layer is a PI electric heating film.

[0028] Furthermore, the heating areas of the fan blade from the front end of the blade to the root of the blade are 1-N in sequence;

[0029] The length direction of the electric heating strips in heating zone 1 and heating zone 2 is consistent with the length direction of the fan blades;

[0030] The length direction of the electric heating strips from heating zone 3 to heating zone N is perpendicular to the length direction of the fan blades.

[0031] The beneficial effects of the present invention are as follows: through the present invention, the length of the fan blade from the end to the root is formed into N zones in an arithmetic progression, and then the layout of the heating strips in each zone is different, thereby forming a local heating of the fan blade, and the driving current of each zone is determined according to the heating resistance value and environmental parameters of different zones, while effectively ensuring the deicing effect and deicing efficiency, it can avoid the increase of deicing loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0033] Figure 1 Flowchart of the present invention.

[0034] Figure 2 Schematic diagram of the layout of heating strips in different zones of the present invention.

[0035] Figure 3 It is a structural schematic diagram of the electric heating strip of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below:

[0037] The present invention provides a fan blade zone heating and deicing control method, comprising the following steps:

[0038] S1. Divide fan blade 1 into N heating zones from the front end to the root of the blade; the lengths of the heating zones from the front end to the root form an arithmetic progression; the length difference between two adjacent zones is the radius of the blade (i.e., its total length) divided by 20. The length of the first zone is determined based on actual operating conditions; specifically:

[0039] The heating areas of the fan blades from the front end to the root of the blades are 1-N in sequence;

[0040] The length direction of the electric heating strips in heating zone 1 and heating zone 2 is consistent with the length direction of the fan blades;

[0041] The length direction of the electric heating strips from heating zone 3 to heating zone N is perpendicular to the length direction of the fan blade. The number of electric heating strips arranged in heating zone 1 and heating zone 2 is decreasing, and the number of electric heating strips from heating zone 3 to heating zone N is also decreasing. Moreover, the lengths of heating zones 1-N are also decreasing, forming an arithmetic progression;

[0042] S2. Provide electric heating strips 2 in each heating zone;

[0043] S3 obtains the parameters of the fan blade environment, and determines the driving current for heating and deicing based on the fan blade environmental parameters;

[0044] S4. Control the operation of the electric heating strips based on the driving current. The above method forms an arithmetic progression of N zones along the length of the fan blade from tip to root. The heating strips in each zone are then arranged differently, thereby achieving localized heating of the fan blade. The driving current for each zone is determined based on the heating resistance and environmental parameters of each zone, effectively ensuring deicing effectiveness and efficiency while avoiding increased deicing losses.

[0045] In this embodiment, the driving current is determined by the following method:

[0046] Determine the critical de-icing power density:

[0047] q cr =I i 2 R i =q R +q C +q wv ;

[0048] Where: q cr is the de-icing critical power density, I i represents the deicing driving current of the ith partition, R i represents the resistance of the ith partition, q R is the radiation heat loss power, q C is the convective heat loss power, qwv is the power density required for ice melting;

[0049] The de-icing driving current I is obtained from the critical de-icing power density i , wherein the control of the current size is achieved through the existing heating drive circuit, which will not be described in detail here.

[0050] Specifically: the radiation heat loss power q R Determined by the following method:

[0051] q R =εσ(T a +273) 3 (TT a );

[0052] Where: ε is the radiation coefficient, σ is the Boltzmann constant, T a is the ambient temperature, and T is the fan blade temperature.

[0053] The convective heat loss power q C Determined by the following method:

[0054] q C =h×(TT a ); where: h is the air convection coefficient; T a is the ambient temperature, and T is the fan blade temperature.

[0055] The air convection coefficient h is determined as follows:

[0056] h=ρ·c·v rel ·st, where: ρ is the air density, v rel is the relative wind speed of air, c is the specific heat capacity of air;

[0057] Intermediate variables Intermediate variables Where l is the chord pitch of the fan blades and η is the air viscosity coefficient.

[0058] In the above, the power density q required for ice melting is wv If it cannot be specifically expressed by a mathematical model, it is necessary to evaluate the amount of ice coverage in each zone through existing ice coverage monitoring methods (such as image monitoring method), and then evaluate the power required to melt the ice under this ice coverage. Through the above method, the driving current required for heating can be more accurately evaluated, thereby avoiding increased energy consumption and saving energy while ensuring the de-icing effect.

[0059] In this embodiment, the electric heating strip includes a heat insulating layer 21, a heating layer 22, a heat conducting layer 23 and a base layer 24 from top to bottom; Figure 3The directions shown in the figure are up and down. Since the blade has two sides and both sides are provided with electric heating strips, the directions shown in the figure are used as the up and down references.

[0060] wherein the base layer is attached to the fan blade and the base layer is epoxy resin;

[0061] The heating layer is a PI electric heating film.

[0062] Among them, the thermal insulation layer uses existing thermal insulation materials to prevent heat loss, and the thermal conductive layer uses thermal conductive silicone, so as to evenly distribute the heat. The function of the base layer is to provide adhesion between the thermal conductive layer, the thermal insulation layer and the heating layer and the surface of the fan blade.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A fan blade zone heating and deicing control method, characterized in that: The following steps are involved: S1. The fan blade is divided into N heating zones from the front end of the blade to the root of the blade; and the length of the heating zone from the front end to the root forms an arithmetic progression; S2. Electric heating strips are provided in each heating zone; S3. Obtaining the parameters of the environment in which the fan blades are located, and determining the driving current for heating and deicing according to the environmental parameters of the fan blades; S4. Control the operation of the electric heating strip according to the driving current.

2. The fan blade zone heating and deicing control method according to claim 1 is characterized in that: The drive current is determined by the following method: Determine the critical de-icing power density: q cr =I i 2 R i =q R +q C +q wv ; Where: q cr is the deicing critical power density, I i represents the deicing driving current of the ith partition, R i represents the resistance of the ith partition, q R is the radiation heat loss power, q C is the convective heat loss power, q wv is the power density required for ice melting; The deicing driving current I is solved from the critical deicing power density i .

3. The fan blade zone heating and deicing control method according to claim 2 is characterized in that: The radiation heat loss power q R Determined by: q R =εσ(T a +273) 3 (T-T a ); Where: ε is the radiation coefficient, σ is the Boltzmann constant, T a is the ambient temperature, and T is the fan blade temperature.

4. The fan blade zone heating and deicing control method according to claim 2 is characterized in that: The convective heat loss power q C Determined by: q C =h×(TT a );where: h is the air convection coefficient; T a is the ambient temperature, and T is the fan blade temperature.

5. The fan blade zone heating and deicing control method according to claim 4 is characterized in that: The air convection coefficient h is determined by the following method: h=ρ·c·v rel ·st, where: ρ is the air density, v rel is the relative air velocity, c is the specific heat capacity of air; Intermediate variables Intermediate variables Among them, l is the chord distance of the fan blades, and η is the air viscosity coefficient.

6. The fan blade zone heating and deicing control method according to claim 1 is characterized in that: The electric heating strip comprises a heat insulating layer, a heating layer, a heat conducting layer and a base layer from top to bottom; wherein the base layer is attached to the fan blade and the base layer is epoxy resin; The heating layer is a PI electric heating film.

7. The fan blade zone heating and deicing control method according to claim 1 is characterized in that: The heating area of ​​the fan blade from the front end of the blade to the root of the blade is 1-N in sequence; The length direction of the electric heating strips in heating zone 1 and heating zone 2 is consistent with the length direction of the fan blades; The length direction of the electric heating strips from heating zone 3 to heating zone N is perpendicular to the length direction of the fan blades.

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