Method for optimizing pre-curing of wind turbine blade webs

Abstract

The application discloses an optimization method for pre-curing of a wind power blade web, which is a resin infusion molding process in the web manufacturing process; when the resin infusion amount reaches 1 / 3-2 / 3 of the total infusion amount, the mold temperature is increased to 55-65 DEG C, the infusion is completed under the temperature, and after the resin heat release peak ends, the mold temperature is adjusted to 70-80 DEG C for heat preservation and curing. The optimization method can effectively reduce the heat release peak temperature in the web curing process without affecting the production cycle, solves the core material burning defect existing in the prior art, reduces the occurrence probability of secondary problems such as high-temperature damage of the vacuum film caused by high temperature, significantly improves the product quality of the wind power blade, optimizes the production process flow, and improves the production efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power blade web production, and particularly relates to an optimization method for pre-curing of a wind power blade web. BACKGROUND

[0002] A wind power blade is one of the core components of a wind turbine generator set, and the quality thereof directly relates to the performance and benefits of the wind turbine. The structure of the wind power blade generally comprises an outer shell, a main beam and a web, etc., wherein the web, as a key structure, supports the main beam and transmits shear force. The production of the wind power blade in the industry generally comprises two processes of pre-curing and post-curing, wherein the pre-curing is a curing process after resin infusion in the web production process, and the post-curing is a curing process after bonding of the shell and components. The existing web for the wind power blade is mainly composed of a layer (i.e., a fiber reinforced material) and a core material, and is formed by a vacuum resin infusion process. The production process generally comprises the following procedures in sequence: outer skin cloth layer laying, core material laying, inner skin cloth layer laying, auxiliary material arrangement and vacuum bagging. Since the resin curing reaction is an endothermic reaction, it is necessary to first heat to accelerate the resin curing. Therefore, the existing web curing process is to open the mold and preheat to 40℃ when the web layering to the auxiliary material arrangement starts, maintain this temperature for vacuum infusion, and then heat the mold to 80℃ for curing after the whole resin infusion is completed, to complete the pre-curing of the web. However, since a large amount of heat is released during the resin curing process, the heat released by the resin reaches a peak during the resin heating and curing to the heat release peak, and since there is a large amount of resin in the infusion runner, heat aggregation is easily generated in the runner area, which causes the core material to be burned and the product to be unqualified due to the high temperature and secondary problems. In actual production, in order to avoid the problem of burning of the core material during the resin curing process, frequent sampling point detection is required, and when the local temperature is too high, spraying or ice packing is used for cooling. This not only increases the workload and production cost, but also affects the product. In order to optimize the production, people try to control the temperature to divide the resin heat release and resin curing into two stages, i.e., adjusting the temperature to 65℃ after the infusion is completed, and then heating to 70-80℃ for curing after the heat release peak is over. Although this adjustment can solve the problem of burning of the core material caused by the heat release peak, it prolongs the pre-curing cycle and affects the overall production. SUMMARY

[0003] In order to solve the defect that the pre-curing of the existing production easily causes the core material to be burned, the present application provides an optimization method for pre-curing of a wind power blade web, which uses an early heating and curing process to make the resin absorb heat in advance, thereby effectively preventing the burning defect of the core material caused by the high temperature of the resin heat release, improving the product quality, and optimizing the post-process without affecting the web forming cycle.

[0004] The optimization method for pre-curing of the wind power blade web of the present application is that, in the resin infusion molding process of the web manufacturing process, when the resin infusion amount reaches 1 / 3-2 / 3 of the total infusion amount, the mold temperature is raised to 55-65℃, the temperature is kept to complete the infusion, and after the end of the resin heat release peak, the mold temperature is adjusted to 70-80℃ for heat preservation curing.

[0005] By heating in advance when the resin infusion amount reaches 1 / 3-2 / 3, the resin flow rate is accelerated, and the resin is heated and cured in advance, the heat release in the initial curing stage is accelerated, and the process temperature in different stages of the web curing process is set in a range, so that the heat release peak temperature is reduced, thereby effectively preventing the core material from being burned due to high resin heat release temperature, and the optimized process does not significantly change the web pre-curing time, eliminates the influence of process adjustment on the web molding production cycle, and further ensures the smooth progress of the overall production.

[0006] As a limitation of the above technical solution, the pre-heating temperature of the infusion auxiliary material arrangement process is 35-45℃, and the resin is infused to 1 / 3-2 / 3 of the total infusion amount at this temperature.

[0007] As a limitation of the above technical solution, the temperature control is controlled by detecting the end time of the resin heat release peak.

[0008] As a limitation of the above technical solution, the overall infusion time is shortened to 50-60min.

[0009] Further limit the pre-curing operation conditions of the web manufacturing process, optimize the web quality and process flow.

[0010] Meanwhile, the present application also provides a wind power blade web prepared by the above optimization method.

[0011] As a limitation of the above technical solution, the web has no core material burning defect.

[0012] The optimization method for pre-curing of the wind power blade web of the present application can effectively reduce the heat release peak temperature of the web curing process, solve the core material burning defect existing in the existing production, reduce the probability of secondary problems such as high-temperature damage of the vacuum film caused by high temperature in the existing process, significantly improve the product quality of the wind power blade, optimize the production process flow, and improve the production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 , the web manufacturing mold of the present application;

[0014] In the figure, 1 is a mold, 2 is an outer skin cloth layer, 3 is a core material, 4 is an inner skin cloth layer, 5 is an integrated flow guide net, and 6 is a flow channel. DETAILED DESCRIPTION

[0015] The technical solutions of the present application will be clearly and completely described below in combination with the embodiments. 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 the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0016] The raw materials involved in the following examples and comparative examples are typical products purchased in the market.

[0017] Example

[0018] The production operation of the wind power blade web is as follows.

[0019] 1. Web manufacturing

[0020] The manufacturing procedures are as follows: outer skin cloth layer laying, core material laying, inner skin cloth layer laying, auxiliary material pouring arrangement, vacuum packaging, etc. Figure 1 as shown in

[0021] (1) Outer skin cloth layer 2 laying: according to the process requirements, the fiberglass cloth layer is laid in the web mold 1 as the outer skin cloth layer 2;

[0022] (2) Core material 3 laying: the core material 3 is laid on the outer skin cloth layer 2 according to the requirements, and is required to be laid in the fixed area;

[0023] (3) Inner skin cloth layer 4 laying: according to the process requirements, the fiberglass cloth layer is laid on the core material 3 as the inner skin cloth layer 4;

[0024] (4) Auxiliary material pouring arrangement: according to the process requirements, the auxiliary materials such as release cloth, integrated flow guide net 5 and flow channel 6 are arranged;

[0025] (5) Vacuum packaging: the vacuum film and the air extraction system are used for vacuum packaging operation, so that the whole web mold 1 presents negative pressure, which is used for pouring the pouring resin.

[0026] 2. Web pre-curing

[0027] (1) Pouring and heating process

[0028] The mold is opened at the beginning of the auxiliary material arrangement process and heated to 35-45℃, so that the mold is in a balanced temperature and suitable pouring state. The resin pouring is maintained at 35-45℃, and the resin flow rate is stabilized through temperature control. When the pouring is performed to about 1 / 3-2 / 3 of the total resin pouring amount, the mold heating temperature is adjusted from 35-45℃ to 55-65℃, and the subsequent resin pouring is maintained at 55-65℃. The pouring rate is improved, not only the pouring time is shortened to 50-60 min, but also the curing reaction starts early in the pouring process.

[0029] The viscosity, flow rate and temperature of the resin are directly related. Increasing the pouring temperature during the pouring process directly changes the pouring flow rate and the impregnation effect of the resin and core material. Since the resin curing reaction process is an endothermic reaction, increasing the temperature in advance causes the resin to start reacting in advance and increases the heating reaction rate. At the same time, the resin curing reaction process releases heat, which provides heat for the curing reaction, so that the curing reaction proceeds in advance.

[0030] (2) Exothermic peak process

[0031] The total heat released during the overall curing process of the resin does not change. In the resin pouring stage, the temperature is increased in advance, so that the heating process starts to release the heat of the curing reaction, which can effectively alleviate the concentrated release of heat in the exothermic peak, reduce the temperature in the flow channel area, effectively avoid the defect of core burning, and improve the quality of the blade.

[0032] (3) Heat preservation curing process

[0033] After the exothermic peak is over, the mold heating temperature is adjusted from 55-65°C to 70-80°C for heat preservation curing. Due to the advance heating in the pouring stage, the pouring time is reduced, and at the same time the curing process is started in advance. After the exothermic peak is over, the mold temperature is increased to 70-80°C, which speeds up the heat preservation curing process of the web, eliminates the influence on the web forming cycle, and keeps the overall curing cycle of the web stable.

[0034] The data of the web pre-curing process are shown in Table 1.

[0035] Table 1

[0036]

[0037] Comparative Example 1

[0038] This comparative example is the web production process before optimization, which is different from the examples in the web pre-curing process operation. Specifically, the mold is preheated to 40°C at the beginning of the web auxiliary material arrangement, and the temperature is maintained to complete the vacuum pouring. The pouring time is 60-70 min. After all the resin is poured, the mold temperature is increased to 80°C for heat preservation curing. During the curing process, the product surface is measured by using thermal imaging, the temperature is > 50°C, and the area with temperature > 50°C is circled with a marker pen and sprayed with ice water continuously. When the surface temperature of the product is higher than 60°C during the heating process, the heat preservation cotton is lifted. Once the temperature is too high, use methods such as spraying or ice compress to cool down until the web pre-curing is completed. The pre-curing time is 5.5-6h, and the obtained web product is detected to have 9 single core burning defects.

[0039] Comparative Example 2

[0040] The present comparative example adjusts the preheating temperature and the curing temperature at holding on the basis of the existing web manufacturing process (same as comparative example 1), and the specific adjustment data are shown in Table 2.

[0041] Table 2

[0042]

[0043]

[0044] Comparative example 3

[0045] The present comparative example adjusts the web pre-curing process, and the specific operation is as follows: the mold is heated to 40 DEG C at the beginning of the web auxiliary material arrangement, the temperature is kept for pouring, the vacuum pouring is completed, the mold is adjusted to 65 DEG C, the heat release peak is ended after 4 hours, then the mold is adjusted to 80 DEG C for curing at holding for 2.5 hours, the web pre-curing is completed, the pre-curing time is 6.5 hours, the obtained web product is detected, the number of single core material burning defects is 1, but compared with the pre-curing time 5.5-6 hours of the previous conventional process, the pre-curing cycle is prolonged, which affects the overall production.

[0046] From the results of the comparative example, it can be seen that the adjustment of the pouring temperature will directly affect the resin flow rate, and then change the pouring time; the increase of the pouring temperature will also affect the pre-curing time, and then affect the product quality and other production conditions.

[0047] In summary, the optimization method of the present application adjusts the web pre-curing process, that is, the mold is heated to 55-65 DEG C when the web resin pouring amount is 1 / 3-2 / 3, the curing process is advanced, the resin heat release process is prolonged, the concentrated heat release of the resin during the heat release peak is effectively controlled, the core material burning under the pouring flow channel caused by too high temperature is avoided, the mold temperature is increased to 70-80 DEG C after the heat release peak is ended, the web curing at holding process is accelerated, the influence of the process adjustment on the web forming cycle is eliminated, not only the product quality of the wind power blade is significantly improved, but also the production process flow is optimized, and the production efficiency is improved.

Claims

1. A method of optimization of pre-curing of a wind turbine blade web, characterized in that: In the resin infusion molding process of the web manufacturing process, when the resin infusion amount reaches 1 / 3 to 2 / 3 of the total infusion amount, the mold temperature is raised to 55 to 65°C, the infusion is completed at this temperature, and after the resin exothermic peak ends, the mold temperature is adjusted to 70 to 80°C for curing; The preheating temperature at the start of the infusion auxiliary material arrangement process is 35 to 45°C, and the resin is infused to 1 / 3 to 2 / 3 of the total infusion amount at this temperature; The temperature control is controlled by detecting the end time of the resin exothermic peak; The infusion time is shortened to 50 to 60 minutes.

2. A wind turbine blade web, characterized in that: Prepared by the optimization method of claim 1.

3. A wind turbine blade web according to claim 2, characterised in that: The web has no core material burning defect.

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