A polyurethane composition for wind turbine blade ballast and a method of making the same

Abstract

This invention discloses a polyurethane composition for wind turbine blade counterweights and its preparation method. The polyurethane composition comprises component A and component B, wherein component A includes a polyether polyol, a chain extender, a catalyst, a dehydrating agent, and a defoamer; component B includes a polyisocyanate and a filler. The preparation method is as follows: the polyether polyol in component A is dehydrated in a vacuum oven with heating and a vacuum pump activated. After dehydration, the water content is measured and is required to be ≤0.1%. The filler in component B is then dehydrated in an oven with heating activated. The dehydrated components A and B are mixed in a vacuum bottle according to their weight proportions, then placed in a vacuum chamber for vacuum degassing. After degassing, the mixture is removed and cured at room temperature to obtain the polyurethane composition for wind turbine blade counterweights. The polyurethane composition of this invention has advantages such as low foaming rate, high density, low modulus, low heat release, and suitable working time.

Description

Technical Field

[0001] This invention belongs to the field of wind power technology, and more specifically, this invention relates to a polyurethane composition for wind turbine blade counterweight and its preparation method. Background Technology

[0002] A wind turbine generator set consists of a rotor and a generator. The rotor rotates under wind power, driving the generator to generate electricity via a transmission system. Each wind turbine generator set consists of three blades. As the core component of the wind turbine, the blades' weight varies due to differences in material usage at different stages of the manufacturing process. Direct installation of these blades can lead to an unbalanced rotor rotation, severely impacting the generator's power generation efficiency, increasing losses, and potentially causing the turbine to overshoot, resulting in significant economic losses and safety hazards. Therefore, during wind turbine blade manufacturing, to ensure that the weight and center of gravity of the blades are similar across the rotor, a counterweight method is used to balance the weight of the lighter blades, using the heaviest blade as a reference.

[0003] Traditional counterweight methods involve directly bonding metal blocks. This method has drawbacks: firstly, due to its chemical properties, it is susceptible to corrosion from moisture and sunlight; secondly, the metal blocks do not bond well to the shell. An improved counterweight method uses adhesives to bond the inner core to the shell, then uses a composite material to cover the metal blocks, which are then hand-laid onto the blade shell. This method solves the bonding problem between the metal blocks and the shell. However, its disadvantages include a complex and time-consuming process, resulting in low blade forming efficiency.

[0004] Patent CN202210474055.0 discloses a method for manufacturing a blade counterweight box. A pre-fabricated counterweight box is glued to the blade tip using adhesive. After weighing, counterweight material is injected into the outer shell using an injection molding tool to counterweight the blade. This counterweight method has the following problems: the counterweight material will generate rigid impacts inside the counterweight box; if the modulus of the counterweight material is too large, the counterweight box may detach; the heat released during the solidification of the counterweight material may damage the shell or counterweight box material; a short working time for the counterweight material will make the injection process difficult, while a long working time will lead to a decrease in production efficiency. Summary of the Invention

[0005] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0006] To achieve these objectives and other advantages of the present invention, a polyurethane composition for wind turbine blade counterweight and a method thereof are provided.

[0007] This invention discloses a polyurethane composition for wind turbine blade counterweight, comprising component A and component B, wherein,

[0008] Component A consists of the following components by weight: 90-100 parts of polyether polyol, 1-10 parts of chain extender, 0.01-0.1 parts of catalyst, 0.5-2 parts of dehydrator, and 0.5-2 parts of defoamer;

[0009] Component B includes: polyisocyanate and filler; the filler is 50-80 parts by weight.

[0010] Preferably, the polyether polyol is one or more of polyether diol and polyether triol; the average molecular weight of the polyether polyol is 200 to 4000; more preferably, the average molecular weight of the polyether polyol is 400 to 2000.

[0011] Preferably, the chain extender is one or more selected from ethylene glycol, 1,2- and 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-quinolinediol, neopentyl glycol, 1,3- and 1,4-di(hydroxymethyl)cyclohexane, 2-methyl-1,3-propanediol, polyethylene glycol, tripropylene glycol, polypropylene glycol, tributylene glycol, polybutanediol, cyclohexanediol, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-pentane-1,3-diol, and glycerol.

[0012] Preferably, the catalyst is one or more of organotin compounds, organobismuth compounds, organozinc compounds, and organocobalt compounds.

[0013] Preferably, the organotin compound is one or more of dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, stannous octanoate, dibutyltin monooctyl maleate, and dibutyltin diacetate; the organobismuth compound is one or more of bismuth isooctanoate, bismuth laurate, bismuth neodecanoate, bismuth naphthenate, and bismuth nitrate; the organozinc compound is one or more of zinc neoquinate, zinc isooctanoate, diethylzinc, and zinc trifluoroacetate; and the organcobalt compound is one or more of cobalt naphthenate and cobalt isooctanoate.

[0014] Preferably, the dehydrating agent is one or more of molecular sieve, p-toluenesulfonate isocyanate, triethyl orthoformate, oxazolidine chemical dehydrating agent, and calcium oxide; and the defoamer is one or more of organosilicon polymer defoamer and defoaming polymer solution.

[0015] Preferably, the polyisocyanate is a diphenylmethane diisocyanate (MDI) monomer or polymer; the isocyanate index is 1.05 to 1.08; preferably, the isocyanate index is 1.06.

[0016] Preferably, the filler is one or more of the following: heavy calcium carbonate, zircon powder, titanium dioxide, barium sulfate, montmorillonite powder, pyrophyllite powder, feldspar powder, wollastonite powder, calcium silicate, coal gangue powder, and magnesium carbonate; the particle size of the filler is ≥400 mesh; preferably, the particle size of the filler is 400-500 mesh.

[0017] A method for preparing a polyurethane composition for wind turbine blade counterweight as described above includes the following steps:

[0018] Step 1: Dehydrate the polyether polyol in component A in a vacuum oven. Turn on the heating and vacuum pump of the vacuum oven, set the temperature to 100-120℃, the vacuum degree to 0.08-0.1MPa, and the dehydration time to 1-3 hours. After dehydration, determine the water content of the polyether polyol using the Karl Fischer method. If the water content is ≤0.1%, proceed to the next step. If the water content is >0.1%, repeat the dehydration step in the oven until the water content is ≤0.1%.

[0019] Step 2: Place the filler in component B into an oven for dehydration treatment. Turn on the oven and set the temperature to 100-120℃. The dehydration time is 1-3 hours.

[0020] Step 3: Place the dehydrated component A and component B into a vacuum bottle according to their weight proportions and shake to mix for 8-12 minutes. After mixing evenly, place the mixture in a vacuum chamber for vacuum degassing treatment. Set the vacuum degree to 0.08-0.1 MPa and the degassing time to 10-20 minutes. After degassing, remove the mixture and place it in a normal environment for room temperature curing to obtain a polyurethane composition for wind turbine blade counterweight.

[0021] Application of a polyurethane composition prepared by the above method as a solid counterweight in wind turbine blade counterweight.

[0022] This invention offers at least the following advantages: The purpose of this invention is to address the problems of high modulus, high rigidity, and unsuitable working time in existing counterweight materials, and to provide a polyurethane composition for wind turbine blade counterweights and its preparation method. This invention incorporates a high molecular weight polyether polyol and a chain extender to increase the molecular chain length, resulting in a polyurethane composition with a large number of active groups, thus exhibiting low modulus and good tensile strength. The addition of a dehydrating agent and defoamer, along with dehydration of the raw materials and defoaming treatment during the synthesis process, prevents the polyurethane composition from foaming. The addition of a catalyst adjusts the system's reaction rate, providing more selectable working times for actual field processes. The addition of a large amount of filler allows the prepared polyurethane composition to simultaneously possess the advantages of high density and low cost. The polyurethane composition of this invention has advantages such as low foaming rate, high density, low modulus, low heat release, and suitable working time, and is mainly applied in the field of wind turbine blade counterweight materials.

[0023] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0024] Figure 1 This is a sample of the polyurethane composition prepared in Example 1. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0026] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0027] The polyisocyanate used in the following examples is polymeric MDI, brand name PM200, with a functionality of 2.7 and a -NCO content of 30.75%, purchased from Wanhua Chemical Polyurethane Co., Ltd.; the polyether polyols include: DL-400, molecular weight 400, hydroxyl value 270, purchased from Shandong Lanxing Dongda Chemical Co., Ltd.; MN-500, molecular weight 500, hydroxyl value 335, purchased from Shandong Lanxing Dongda Chemical Co., Ltd.; DDL-2000D, molecular weight 2000, hydroxyl value 28, purchased from Zibo Dexin Federal Chemical Industry Co., Ltd.; the catalyst is CUCAT-H, purchased from Guangdong Yourun Synthetic Materials Co., Ltd.; the dehydrating agent is additive TI, purchased from Borcbers GmbH, Germany; the defoamer is BYK-535, purchased from BYK Chemicals; the filler is zircon powder with a particle size of 450 mesh.

[0028] Examples 1-4 and Comparative Example 1

[0029] A polyurethane composition for wind turbine blade counterweight and its preparation method, comprising the following steps:

[0030] Step 1: Dehydrate DDL-400, MN-500, and DDL-2000D in component A in a vacuum oven. Turn on the heating and vacuum pump of the vacuum oven, set the temperature to 105℃, the vacuum degree to 0.09MPa, and the dehydration time to 2 hours. After dehydration, determine the water content of the polyether polyol using the Karl Fischer method. If the water content is ≤0.1%, proceed to the next step. If the water content is >0.1%, repeat the dehydration step in the oven until the water content is ≤0.1%.

[0031] Step 2: Place the zircon powder in component B into an oven for dehydration treatment. Turn on the oven and set the temperature to 105℃. The dehydration time is 2 hours.

[0032] Step 3: Mix the dehydrated components A and B according to the weight proportions in Table 1, place them in a vacuum bottle, and shake to mix for 10 minutes, with an isocyanate index of 1.06. After thorough mixing, place the mixture in a vacuum chamber for vacuum degassing treatment. The vacuum level is set to 0.09 MPa, and the degassing time is 15 minutes. After degassing, remove the mixture and place it in a normal environment for room temperature curing to obtain a polyurethane composition for wind turbine blade counterweights. The polyurethane composition sample prepared in Example 1 is shown below. Figure 1 As shown.

[0033] Table 1

[0034]

[0035] The mechanical properties of Examples 1-4 and Comparative Example 1 were measured, and the results are shown in Table 2.

[0036] Table 2

[0037] Example 1 8.6 0.44 ＞20 Example 2 9.2 0.49 ＞20 Example 3 14.6 0.76 ＞20 Example 4 22 1.2 ＞20 Comparative Example 1 1.8 0.01 ＞20

[0038] It is evident that the addition of the chain extender of the present invention results in higher tensile strength and better overall performance of the polyurethane composition.

[0039] Examples 5-7 and Comparative Example 2

[0040] A polyurethane composition for wind turbine blade counterweight and its preparation method are disclosed. The composition and preparation method in Example 1 are used, except that the amount of catalyst CUCAT-H component is changed, as shown in Table 3.

[0041] Table 3

[0042] CUCAT-H 0 0.02 0.04 0.06 0.08

[0043] The gelation time was determined with the mixed viscosity reaching 600 mPa·s at 25℃ as the criterion, and the results are shown in Table 4.

[0044] Table 4

[0045] Comparative Example 2 198 Example 5 89 Example 1 55 Example 6 23 Example 7 5

[0046] It is evident that by using CUCAT-H of the present invention as a catalyst, the reaction rate of the system can be adjusted, providing more selectable operating times for actual on-site processes.

[0047] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A polyurethane composition for wind turbine blade ballast, characterized in that, Including component A and component B, wherein, Component A consists of the following components by weight: 97 parts polyether polyol, 1-3 parts chain extender, 0.01-0.1 parts catalyst, 1-2 parts dehydrator, and 1-2 parts defoamer; Component B includes: polyisocyanate and filler; the filler is 50-80 parts by weight. The chain extender is glycerol; the catalyst is CUCAT-H; the dehydrating agent is additive TI; and the defoamer is BYK-535. The polyether polyols are DL-400, MN-500 and DDL-2000D; the mass ratio of DL-400, MN-500 and DDL-2000D is 40:32:25, or 32:37:28, or 32:45:20, or 40:37:

20. The filler is one or more of the following: heavy calcium carbonate, zircon powder, titanium dioxide, barium sulfate, montmorillonite powder, pyrophyllite powder, feldspar powder, wollastonite powder, calcium silicate, coal gangue powder, and magnesium carbonate; the particle size of the filler is 400-500 mesh. The polyisocyanate is a diphenylmethane diisocyanate monomer or polymer with an isocyanate index of 1.

06. The application of the polyurethane composition as a solid counterweight in wind turbine blade counterweight; The method for preparing the polyurethane composition for wind turbine blade counterweight includes the following steps: Step 1: Dehydrate the polyether polyol in component A in a vacuum oven. Turn on the heating and vacuum pump of the vacuum oven, set the temperature to 100~120℃, the vacuum degree to 0.08~0.1MPa, and the dehydration time to 1~3 hours. After dehydration, determine the water content of the polyether polyol using the Karl Fischer method. If the water content is ≤0.1%, proceed to the next step. If the water content is >0.1%, repeat the dehydration step in the oven until the water content is ≤0.1%. Step 2: Place the filler in component B into an oven for dehydration treatment. Turn on the oven and set the temperature to 100~120℃. The dehydration time is 1~3 hours. Step 3: Place the dehydrated component A and component B into a vacuum bottle according to their weight proportions and shake to mix for 8-12 minutes. After mixing evenly, place the mixture in a vacuum chamber for vacuum degassing treatment. Set the vacuum degree to 0.08-0.1 MPa and the degassing time to 10-20 minutes. After degassing, remove the mixture and place it in a normal environment for room temperature curing to obtain a polyurethane composition for wind turbine blade counterweight.

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