Vacuum infusion bag membrane structure for wind turbine blade
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2026-06-19
Smart Images
Figure CN224374942U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of wind turbine blade technology, and in particular to a vacuum-filled bag membrane structure for wind turbine blades. Background Technology
[0002] Vacuum infusion is a commonly used composite material molding method in the manufacturing process of wind turbine blades. This process involves injecting resin into pre-laid fiber-reinforced materials and curing it in a vacuum environment to ultimately form a high-strength composite material structure.
[0003] However, during the vacuum infusion and curing process, the exothermic reaction of the resin may cause localized excessively high temperatures. Traditional temperature monitoring methods (such as thermocouples or infrared thermometry) can usually only achieve "point" or "line" monitoring, which is difficult to cover the entire surface of the wind turbine blade and has monitoring blind spots. As a result, there are still high quality risks and production costs in the manufacturing process of wind turbine blades. Utility Model Content
[0004] The purpose of this application is to provide a vacuum infusion bag membrane structure for wind turbine blades. By setting a temperature-sensitive color-changing layer on the bag membrane, a real-time and visual temperature monitoring method can be provided when the blade is heated and cured or maintained and heated.
[0005] This utility model provides a vacuum injection bag membrane structure for wind turbine blades, including:
[0006] At least one bag film, the bag film comprising a substrate layer and a thermo-sensitive color-changing layer, the thermo-sensitive color-changing layer being disposed on or embedded in the substrate layer;
[0007] The thermochromic layer is configured to change color in response to temperature changes, and is used to monitor local temperature anomalies during the vacuum injection process of wind turbine blades. When the temperature in the area covered by the thermochromic layer exceeds a preset threshold, the thermochromic layer changes from a first color to a second color, and the first color and the second color are different.
[0008] Beneficial Effects: This vacuum-filled bag membrane structure for wind turbine blades features a substrate layer that ensures good sealing and mechanical strength. By incorporating a thermosensitive color-changing layer on the bag membrane, real-time, visualized temperature monitoring is provided during blade heating and curing or maintenance. The thermosensitive color-changing layer can cover the entire bag membrane or a portion of it, allowing the covered area to monitor localized temperature anomalies during the vacuum filling process when the bag membrane is attached to the wind turbine blade surface. Once the surface temperature of the covered area exceeds a preset threshold, the color changes from a first color to a second color (e.g., from light to dark), allowing operators to visually observe the changed area. This enables comprehensive, real-time temperature monitoring of the wind turbine blade surface, preventing overheating issues from being overlooked due to blind spots.
[0009] During vacuum infusion and curing, the exothermic reaction of the resin can easily lead to localized overheating. This bag-film structure can respond quickly to temperature changes; when the local temperature abnormally rises above a preset threshold, the area covered by the thermosensitive color-changing layer immediately changes color, promptly alerting operators. It can detect localized temperature anomalies in a timely manner, allowing operators to intervene promptly, effectively avoiding quality problems caused by localized overheating, reducing the defect rate of blades, improving product quality, and ensuring the reliability and stability of wind turbine blades in actual operation.
[0010] Meanwhile, temperature monitoring using this bag-membrane structure eliminates the need for complex equipment installation and debugging; operators can determine blade temperature simply by observing changes in the bag's color. Compared to traditional monitoring methods that require wiring with thermocouples or specialized equipment and calibration for infrared thermometry, this bag-membrane structure simplifies the operation process and reduces equipment procurement, installation, and maintenance costs.
[0011] Furthermore, the usage of this bag film structure is basically the same as that of ordinary bag films, requiring no changes to vacuum extraction, laying methods, or curing processes. Only a thermosensitive color-changing layer needs to be added to the multi-layered structure of the bag film itself, resulting in minimal process modifications and easy large-scale deployment.
[0012] In one optional embodiment, the thermochromic layer is a reversible thermochromic layer. When the surface temperature of the area covered by the thermochromic layer decreases from a state exceeding the preset threshold to a state below the preset threshold, the color of the area covered by the thermochromic layer changes from the second color to the first color.
[0013] Beneficial Effects: In the production of wind turbine blades, resin curing is a dynamic process with constantly changing temperatures. The reversible thermochromic layer can track temperature changes in real time. When the temperature of the area covered by the thermochromic layer exceeds a preset threshold, the color changes from the first color to the second color, alerting operators to an abnormal temperature. When the temperature returns to normal, the color changes back to the first color. This allows operators to continuously monitor temperature fluctuations and promptly identify potential problems. In the early stages of resin curing, due to the intense chemical reaction, local temperatures may fluctuate frequently. The reversible color-changing characteristic allows operators to monitor the temperature at any time, ensuring the entire curing process is conducted within a suitable temperature range. If an abnormal temperature is detected during production, operators can take measures to cool down the area. Once the temperature returns to normal, the reversible thermochromic layer will return to its first color, allowing subsequent operations to continue without waiting for the entire production process to end before checking and adjusting. This avoids production interruptions and delays caused by temperature issues, improving production efficiency.
[0014] The reversible color-changing characteristic helps operators analyze temperature change trends. By observing the frequency and duration of color changes, the severity and duration of temperature anomalies can be determined. Frequent color changes in a certain area indicate large temperature fluctuations, potentially indicating poor heat dissipation or other problems; prolonged color changes suggest a more severe temperature anomaly, requiring timely adjustment of process parameters.
[0015] In one optional embodiment, the thermochromic layer is an irreversible thermochromic layer. When the surface temperature of the area covered by the thermochromic layer decreases from a state exceeding the preset threshold to a state below the preset threshold, the color of the area covered by the thermochromic layer remains the second color.
[0016] Beneficial effects: The irreversible color-changing layer accurately records situations where the temperature exceeds a preset threshold. Regardless of subsequent temperature changes, the color-changing area retains its second color, providing a direct and tamper-proof record of temperature anomalies for the production process. This helps operators clearly understand which parts of the blades have experienced temperature problems, as well as the approximate severity and scope of the problems, during subsequent quality inspection and analysis, facilitating the tracing and investigation of potential quality hazards.
[0017] The preset threshold temperature for reversible color-changing coatings is generally between 50°C and 80°C. If the temperature of the wind turbine blade exceeds 80°C, the reversible color-changing coating will not change color according to the established mechanism to alert the operator because it exceeds its set threshold range. The preset threshold temperature for irreversible color-changing coatings can be flexibly set to exceed 80°C. When the temperature of the wind turbine blade exceeds 80°C, the irreversible color-changing coating can change color to alert the operator based on its own set threshold above 80°C, preventing the membrane from being damaged by high temperatures and causing rupture.
[0018] In one optional embodiment, at least two bags are provided, and at least two bags are sequentially fitted together;
[0019] Wherein, at least one of the thermosensitive color-changing layers of the bag film is a reversible color-changing layer, and at least one of the thermosensitive color-changing layers of the bag film is an irreversible color-changing layer.
[0020] Beneficial effects: The preset threshold temperature for reversible chromatic coatings is generally between 50°C and 80°C, while the preset threshold temperature for irreversible chromatic coatings can exceed 80°C. Combining the two allows for effective monitoring of a wider temperature range. Under normal temperature fluctuations, the reversible chromatic coating can provide real-time feedback on temperature changes, allowing operators to understand whether the temperature is fluctuating within the normal range. However, when the temperature exceeds 80°C, the irreversible chromatic coating begins to function, filling the monitoring gap of the reversible chromatic coating in the high-temperature range and ensuring effective monitoring of the entire temperature range of wind turbine blades.
[0021] By observing the color changes of reversible and irreversible color-changing layers on different bags, operators can more accurately determine potential problems with wind turbine blades. For example, if the reversible color-changing layer shows a normal temperature, but the irreversible color-changing layer has changed color, it indicates that the blade may have experienced a brief period of abnormal high temperature.
[0022] Using at least two membrane bags, each with a reversible and an irreversible color-changing layer, effectively adds redundancy to the temperature monitoring system. Even if one membrane bag or color-changing layer malfunctions or is interfered with by external factors, the other membrane bag and color-changing layer can still function normally and continue to provide temperature information, ensuring the reliability of the entire monitoring system and reducing the risk of safety accidents due to monitoring failure.
[0023] In one optional embodiment, the thermochromic layer is disposed on the outer surface of the substrate layer.
[0024] Beneficial effects: The thermochromic layer, located on the outer surface, can directly contact the external environment or the monitored object, allowing for faster and more accurate sensing of temperature changes. Eliminating the need for heat transfer through intermediate media such as a substrate layer reduces heat loss and delay during the transfer process, enabling the thermochromic layer to more sensitively capture subtle temperature changes and improve the accuracy of temperature monitoring. Furthermore, the outer surface of the thermochromic layer makes it easier to observe, allowing people to directly and intuitively obtain color change information from the outside.
[0025] In one alternative embodiment, the thermochromic layer is applied to the outer surface of the substrate layer by spraying, printing, or hot-pressing.
[0026] Beneficial effects: Spraying the thermochromic layer onto the outer surface of the substrate layer ensures uniform coverage, guaranteeing accurate and consistent temperature monitoring. The thickness of the thermochromic layer can be easily controlled by adjusting the number of sprays, the paint concentration, and the parameters of the spraying equipment to meet different temperature sensitivity requirements and application needs. Furthermore, the spraying method is relatively fast, suitable for large-scale production, enabling the preparation of thermochromic layers on a large number of substrates in a short time, improving production efficiency and reducing production costs.
[0027] By dispersing thermochromic pigments into ink and applying them to the outer surface of a substrate layer through printing, it is possible to achieve partial pattern printing (such as temperature warning labels) or full-coverage printing, so as to facilitate personalized design.
[0028] Thermo-pressing can be used to bond the existing thermochromic layer to the outer surface of the substrate layer, which is beneficial for controlling the distribution of material quality and allows for bonding in specific areas of the substrate layer as needed.
[0029] In one alternative embodiment, the bag film further includes a protective layer covering the outer surface of the thermochromic layer.
[0030] Beneficial effects: In actual use, the surface of the bag film may be scratched by tools or other parts. By setting a protective layer on the outer surface of the thermochromic layer, the thermochromic layer is prevented from being directly worn and scratched, thereby maintaining the integrity and performance of the thermochromic layer.
[0031] In one optional embodiment, the thermochromic layer and the substrate layer are formed into the bag film by multi-layer co-extrusion, and the thermochromic layer is embedded in the substrate layer.
[0032] Beneficial effects: Multi-layer co-extrusion allows the thermo-sensitive color-changing layer and the substrate layer to fuse together at the molecular level, forming a tight whole. This significantly improves the adhesion between the two layers, effectively preventing the thermo-sensitive color-changing layer from peeling or flaking during use, and ensuring the stability and integrity of the bag film structure.
[0033] During the multi-layer co-extrusion process, the thermochromic layer can be uniformly embedded in the substrate layer, avoiding local over-thickness or under-thinness, ensuring the consistency and stability of the thermochromic function across the entire bag film surface, so that the bag film can accurately sense temperature and exhibit corresponding color changes at different locations.
[0034] Embedding the thermochromic layer within the substrate layer provides physical protection, shielding it from direct environmental influences such as abrasion, scratches, UV radiation, and chemical corrosion. This helps maintain the thermochromic layer's performance, extends its lifespan, and ensures it continues to respond accurately to temperature during long-term use.
[0035] In addition, multilayer co-extrusion is a continuous processing technology that can complete the bonding of the thermosensitive color-changing layer and the substrate layer in one operation, which greatly improves production efficiency and reduces production costs.
[0036] In one alternative embodiment, the substrate layer is made of a thermoplastic polymer.
[0037] Beneficial effects: Thermoplastic polymers can be nylon, polyethylene, ethylene-vinyl acetate copolymer, etc. Nylon has excellent mechanical strength and wear resistance, and the bags and films made from it can withstand greater tensile force and friction, and are not easy to break or be damaged.
[0038] Polyethylene has high chemical stability and is not easily corroded. It also has good transparency, so the wind turbine blades inside the bag membrane can be clearly seen. When the color of the bag membrane changes, the operator can technically observe the color change.
[0039] Ethylene-vinyl acetate copolymer has good elasticity and flexibility, and can quickly and firmly seal during the heat sealing process, forming a good sealing effect and preventing bag film leakage. At the same time, it has high heat sealing strength, which can ensure the sealing and integrity of the bag film during use.
[0040] Polyester has extremely high transparency and gloss, as well as high strength, hardness and rigidity. The bag film can withstand great pressure and weight, is not easily deformed, and can provide reliable support and protection for the items inside the bag film.
[0041] In one alternative embodiment, the thickness of the substrate layer is 30 μm-150 μm.
[0042] Beneficial effects: When the substrate layer thickness is above 30μm, it provides sufficient structural support for the bag film, giving it good tensile strength and tear resistance, making it less prone to breakage or damage during use. It can withstand items of a certain weight and a certain degree of external pressure and friction. A thickness not exceeding 150μm ensures that the bag film does not become too rigid and brittle due to excessive thickness, maintaining good flexibility and folding resistance, facilitating folding and sealing operations. It can also buffer energy through deformation when subjected to external forces, reducing the risk of breakage. Attached Figure Description
[0043] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0044] Figure 1 This is a cross-sectional view of a vacuum-filled bag membrane structure for a wind turbine blade according to one embodiment provided in this application;
[0045] Figure 2 This is a cross-sectional view of the vacuum-filled bag membrane structure of a wind turbine blade in another embodiment provided in this application.
[0046] Explanation of reference numerals in the attached figures:
[0047] 100. Bag film; 110. Substrate layer; 120. Thermosensitive color-changing layer; 130. Protective layer. Detailed Implementation
[0048] In related technologies, vacuum infusion is a commonly used composite material molding method in the manufacturing process of wind turbine blades. However, during vacuum infusion and curing, the exothermic reaction of the resin may lead to excessively high local temperatures. Traditional temperature monitoring methods (such as thermocouples or infrared thermometry) can usually only achieve "point" or "line" monitoring, which is difficult to cover the entire surface of the wind turbine blade, resulting in monitoring blind spots. This leads to high quality risks and production costs in the manufacturing process of wind turbine blades.
[0049] To address this issue and reduce blind spots in monitoring the surface temperature of wind turbine blades during manufacturing, the inventors of this application have installed numerous sensors around the wind turbine blades to monitor their temperature. Because wind turbine blades are relatively large, a large number of sensors are required, increasing production costs and equipment maintenance complexity.
[0050] Based on this, the inventors of this application have invented a vacuum infusion bag membrane structure for wind turbine blades. By setting a thermosensitive color-changing layer on the bag membrane, a real-time and visual temperature monitoring method can be provided during blade heating and curing or maintenance heating. The thermosensitive color-changing layer can cover the entire bag membrane or a part of the bag membrane, so that when the bag membrane is attached to the surface of the wind turbine blade, the covered area of the thermosensitive color-changing layer can be used to monitor local temperature anomalies during the vacuum infusion process of the wind turbine blade. Once the surface temperature of the area covered by the thermosensitive color-changing layer exceeds a preset threshold, the color changes from the first color to the second color (e.g., from light to dark), and the operator can intuitively see the color-changing area, realizing comprehensive and real-time temperature monitoring of the surface of the wind turbine blade, and avoiding the neglect of local overheating problems due to monitoring blind spots.
[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.
[0052] To solve the above technical problems, the following will be combined with... Figures 1 to 2 The following describes embodiments of the present invention.
[0053] According to embodiments of the present invention, on the one hand, such as Figures 1 to 2 As shown, a vacuum injection bag membrane structure for wind turbine blades is provided, including a bag membrane 100, wherein at least one bag membrane 100 is provided.
[0054] Specifically, such as Figure 1 and Figure 2 As shown, the bag film 100 includes a substrate layer 110 and a thermo-sensitive color-changing layer 120, wherein the thermo-sensitive color-changing layer 120 is disposed on the substrate layer 110 or embedded in the substrate layer 110.
[0055] Specifically, the thermochromic layer 120 is configured to change color in response to temperature changes, and is used to monitor local temperature anomalies during the vacuum injection process of wind turbine blades. When the temperature in the area covered by the thermochromic layer 120 exceeds a preset threshold, the thermochromic layer 120 changes from a first color to a second color, and the first color and the second color are different.
[0056] This wind turbine blade vacuum infusion bag membrane structure features a substrate layer 110 on the bag membrane 100, which ensures good sealing and mechanical strength. A thermosensitive color-changing layer 120 is installed on the bag membrane 100, providing real-time, visualized temperature monitoring during blade heating and curing or maintenance heating. The thermosensitive color-changing layer 120 can cover the entire bag membrane 100 or a portion of it, allowing the covered area to monitor localized temperature anomalies during the vacuum infusion process when the bag membrane 100 is attached to the wind turbine blade surface. Once the surface temperature of the area covered by the thermosensitive color-changing layer 120 exceeds a preset threshold, the color changes from a first color to a second color (e.g., from light to dark), allowing operators to visually observe the color-changing area. This enables comprehensive, real-time temperature monitoring of the wind turbine blade surface, preventing localized overheating issues from being overlooked due to blind spots.
[0057] During vacuum infusion and curing, the exothermic reaction of the resin can easily lead to localized overheating. This bag-film structure can respond rapidly to temperature changes; when a localized temperature abnormally rises above a preset threshold, the area covered by the temperature-sensitive color-changing layer 120 immediately changes color, promptly alerting operators. This timely detection of localized temperature anomalies allows for prompt intervention, effectively preventing quality problems caused by localized overheating, reducing the defect rate of wind turbine blades, improving product quality, and ensuring the reliability and stability of wind turbine blades in actual operation.
[0058] Meanwhile, using this bag-membrane structure for temperature monitoring eliminates the need for complex equipment installation and debugging. Operators can determine the temperature of the wind turbine blades simply by observing the color change of the bag membrane. Compared to traditional monitoring methods that require wiring for thermocouples or specialized equipment and calibration maintenance for infrared thermometry, this bag-membrane structure simplifies the operation process and reduces equipment procurement, installation, and maintenance costs.
[0059] Furthermore, the usage of this bag film structure is basically the same as that of ordinary bag film 100, without the need to change the vacuum extraction, laying method, or curing process. It is only necessary to add a thermosensitive color-changing layer 120 to the multi-layer structure of the bag film 100 itself, which requires minimal process modification and is easy to promote on a large scale.
[0060] Specifically, the substrate layer 110 can be made of high-temperature resistant polymers, such as nylon and polyethylene. In this embodiment, the material of the substrate layer 110 is not specifically limited.
[0061] Specifically, the thermochromic layer 120 is a functional layer that is sensitive to temperature changes and can intuitively present temperature information through color changes. The thermochromic layer 120 is mainly composed of thermosensitive pigments / microcapsules and binders or dispersion media. It achieves color change through specific chemical reactions or physical changes and has a variety of characteristics and application advantages.
[0062] Specifically, the thermochromic layer 120 can be deposited on the outer surface of the substrate layer 110. The outer surface of the substrate layer 110 can be entirely covered by the thermochromic layer 120, or only partially covered. In this embodiment, there is no specific limitation on the size of the thermochromic layer 120 and the substrate layer 110. Alternatively, the thermochromic layer 120 can be embedded within the substrate layer 110.
[0063] It should be noted that the first color and the second color are different. The first color represents the color of the membrane 100 under normal temperature conditions of the wind turbine blade, while the second color represents the color of the membrane 100 when the temperature exceeds a preset threshold. In actual production, if the thermosensitive color-changing layer 120 of the membrane 100 is set to a light color, such as light blue, under normal conditions, when the local temperature exceeds the preset threshold, such as reaching 60℃, the thermosensitive color-changing layer 120 turns into a dark color, such as dark black. Operators can quickly detect temperature abnormalities from the obvious color change, and can intuitively determine which areas on the surface of the wind turbine blade are too hot without the need for additional complex equipment or data analysis.
[0064] Specifically, the choice of the first and second colors can be adjusted according to the actual production scenario and needs. For some wind turbine blade materials or production processes that are more sensitive to temperature changes, a color combination with higher contrast, such as yellow and red, can be selected to make the temperature change display more prominent. For situations where it is necessary to distinguish different temperature ranges, multiple different second colors can be set to correspond to different temperature thresholds, providing operators with more detailed temperature information and helping them to control the production process more accurately.
[0065] In one embodiment, the thermochromic layer 120 is a reversible thermochromic layer. When the surface temperature of the area covered by the thermochromic layer 120 decreases from a state exceeding a preset threshold to a state below a preset threshold, the color of the area covered by the thermochromic layer 120 changes from a second color to a first color.
[0066] In the production of wind turbine blades, resin curing is a dynamic process with constantly changing temperatures. The reversible thermochromic layer 120 tracks these temperature changes in real time. When the temperature in the area covered by the thermochromic layer 120 exceeds a preset threshold, the color changes from the first color to the second color, alerting the operator to a temperature anomaly. When the temperature returns to normal, the color changes back to the first color. This allows operators to continuously monitor temperature fluctuations and promptly identify potential problems. In the early stages of resin curing, due to the intense chemical reaction, local temperatures may fluctuate frequently. The reversible color-changing characteristic allows operators to monitor the temperature at any time, ensuring the entire curing process occurs within a suitable temperature range. If a temperature anomaly is detected during production, operators can take measures to cool the area. Once the temperature returns to normal, the reversible thermochromic layer 120 will revert to its first color, allowing subsequent operations to continue without waiting for the entire production process to finish before checking and adjusting. This avoids production interruptions and delays caused by temperature issues, improving production efficiency.
[0067] The reversible color-changing characteristic helps operators analyze temperature change trends. By observing the frequency and duration of color changes, the severity and duration of temperature anomalies can be determined. Frequent color changes in a certain area indicate large temperature fluctuations, potentially indicating poor heat dissipation or other problems; prolonged color changes suggest a more severe temperature anomaly, requiring timely adjustment of process parameters.
[0068] Specifically, wind turbine blade production is typically large-scale and continuous. The reversible thermochromic layer 120 can be used multiple times, effectively monitoring temperature in each production cycle. Compared to disposable or irreversible monitoring methods, this significantly reduces production costs. For example, if a production line produces multiple wind turbine blades daily, using an irreversible thermochromic film 100 would require replacing it every time, resulting in high costs. The reversible thermochromic film 100, however, can be reused repeatedly, and as long as its performance remains stable, it can continuously serve production.
[0069] Specifically, the material of the reversible color-changing layer can be inorganic thermochromic material, organic thermochromic material, etc. In this embodiment, no specific limitation is made on the material of the reversible color-changing layer.
[0070] For example, the material of the reversible color-changing layer can be pure VO2, an inorganic thermochromic material, whose color changes with temperature and composition. Within a certain temperature range, the color can reversibly change between colorless, light yellow, and dark blue.
[0071] For example, the material of the reversible color-changing layer can be a spiropyran-based organic thermochromic material. At different temperatures, the molecular structure will switch between a spirocyclic structure and an open-ring structure, thereby causing a color change, such as from colorless to blue or purple.
[0072] In one embodiment, the thermochromic layer 120 is an irreversible thermochromic layer. When the surface temperature of the area covered by the thermochromic layer 120 decreases from a state exceeding a preset threshold to a state below a preset threshold, the color of the area covered by the thermochromic layer 120 remains the second color.
[0073] The irreversible color-changing layer accurately records temperatures exceeding a preset threshold. Regardless of subsequent temperature changes, the color-changing area retains its second color, providing a clear and tamper-proof record of temperature anomalies during production. This helps operators clearly understand which parts of the wind turbine blades experienced temperature problems, as well as the approximate severity and scope of the issues, facilitating the tracing and investigation of potential quality hazards during subsequent quality inspections and analyses.
[0074] The preset threshold temperature for reversible color-changing layers is generally between 50°C and 80°C. If the temperature of the wind turbine blade exceeds 80°C, the reversible color-changing layer will not change color according to the established color-changing mechanism to alert the operator because it exceeds its set threshold range. The preset threshold temperature for irreversible color-changing layers can be flexibly set to exceed 80°C. When the temperature of the wind turbine blade exceeds 80°C, the irreversible color-changing layer can change color to alert the operator based on its own set threshold above 80°C, preventing the membrane 100 from being damaged by high temperature and causing rupture.
[0075] There are many types of materials used for irreversible color-changing layers. Commonly used materials include phosphates, sulfates, nitrates, oxides, and sulfides of lead, nickel, chromium, zinc, cobalt, iron, cadmium, strontium, magnesium, barium, molybdenum, and manganese, as well as methyl violet, phenolic compounds, acid clay, azo pigments, and arylmethane pigments. Specifically, high-temperature resistant fluorane dyes can be used as leuco dyes, p-toluenesulfonic acid as a color developer, and microencapsulated for one-time temperature indication at around 100°C.
[0076] In one embodiment, at least two bags 100 are provided, and at least two bags 100 are sequentially nested. Among them, at least one bag 100 has a thermosensitive color-changing layer 120 that is a reversible color-changing layer, and at least one bag 100 has a thermosensitive color-changing layer 120 that is an irreversible color-changing layer.
[0077] The preset threshold temperature for reversible chromatic anodes is typically between 50°C and 80°C, while the preset threshold temperature for irreversible chromatic anodes can exceed 80°C. Combining the two allows for effective monitoring of a wider temperature range. Under normal temperature fluctuations, the reversible chromatic anode provides real-time feedback on temperature changes, allowing operators to understand whether the temperature is fluctuating within the normal range. However, when the temperature exceeds 80°C, the irreversible chromatic anode comes into play, filling the monitoring gap of the reversible chromatic anode in the high-temperature range and ensuring effective monitoring of the entire temperature range of wind turbine blades.
[0078] By observing the color changes of the reversible and irreversible color-changing layers on different bag membranes 100, operators can more accurately determine potential problems with the wind turbine blades. For example, if the reversible color-changing layer shows a normal temperature, but the irreversible color-changing layer has changed color, it indicates that the blade may have experienced a brief period of abnormal high temperature.
[0079] Using at least two membrane bags 100, with reversible and irreversible color-changing layers respectively, effectively adds redundancy to the temperature monitoring system. Even if one membrane bag 100 or one color-changing layer malfunctions or is interfered with by external factors, the other membrane bag 100 and color-changing layer can still function normally and continue to provide temperature information, ensuring the reliability of the entire monitoring system and reducing the risk of safety accidents caused by monitoring failure.
[0080] For example, taking two film bags 100 as an example, one film bag 100 is placed on top of the other film bag 100. One film bag 100 is a reversible color-changing layer, and the other film bag 100 is an irreversible color-changing layer. The reversible color-changing layer is responsible for monitoring changes within the normal operating temperature range, allowing operators to understand the real-time temperature status of the blades and determine whether the operation is normal. The irreversible color-changing layer focuses on monitoring high-temperature anomalies. As long as the temperature exceeds 80°C, it will leave a color change record, providing operators with clear evidence that the blades have experienced high temperatures, regardless of subsequent temperature changes. The second color of the reversible color-changing layer of film bag 100 can be black, and the second color of the irreversible color-changing layer of film bag 100 can be red. Because the two colors are different, operators can directly determine the temperature of the area covered by the temperature-sensitive color-changing layer 120 by observing the color.
[0081] In the vacuum infusion process, the membrane bag 100, which is attached to the wind turbine blade, can be connected to the vacuum extraction hole on the mold. This allows air to be extracted from the membrane bag 100, creating a vacuum. This removes air from the mold and the surface of the material to be infused, preventing air bubbles from forming during infusion and improving the density and quality of the infusion. The remaining membrane bags 100 can also be connected to the vacuum extraction holes on the mold, responsible for extracting air between adjacent membrane bags 100. After air extraction, the membrane bags 100 can fit tightly together, allowing even membrane bags 100 not directly attached to the wind turbine blade to accurately monitor the blade temperature. Because the tight fit facilitates heat conduction, the temperature monitoring function of the membrane bags 100 is not affected by the air layer, accurately reflecting the temperature changes of the wind turbine blade and providing reliable data for monitoring and maintaining the operating status of the wind turbine blade.
[0082] In one embodiment, such as Figure 1 As shown, the thermochromic layer 120 is disposed on the outer surface of the substrate layer 110.
[0083] The thermochromic layer 120, located on the outer surface, can directly contact the external environment or the monitored object, allowing for faster and more accurate sensing of temperature changes. Without the need for heat transfer through intermediate media such as the substrate layer 110, heat loss and delay during heat transfer are reduced, enabling the thermochromic layer 120 to more sensitively capture subtle temperature changes and improve the accuracy of temperature monitoring. Being on the outer surface, the thermochromic layer 120 is also easier to observe, allowing people to directly and intuitively obtain color change information from the outside.
[0084] Specifically, the thermochromic layer 120 can be disposed on the inner surface of the substrate layer 110, allowing it to be directly bonded to the wind turbine blade. Alternatively, the thermochromic layer 120 can be disposed on both the inner and outer surfaces of the substrate layer 110. By disposing of multiple thermochromic layers 120, when all layers change color simultaneously, the color change will be very noticeable, promptly attracting the attention of operators.
[0085] In one embodiment, the thermochromic layer 120 is disposed on the outer surface of the substrate layer 110 by spraying, printing or hot pressing.
[0086] Thermosensitive color-changing layer 120 is sprayed onto the outer surface of substrate layer 110, ensuring uniform coverage and accurate, consistent temperature monitoring. The thickness of thermosensitive color-changing layer 120 can be easily controlled by adjusting the number of sprays, paint concentration, and spraying equipment parameters to meet varying temperature sensitivity and application requirements. Furthermore, spraying is a relatively fast method suitable for large-scale production, enabling the preparation of thermosensitive color-changing layer 120 on a large number of substrates in a short time, thus improving production efficiency and reducing costs.
[0087] By dispersing thermochromic pigments into ink and applying them to the outer surface of the substrate layer 110 through printing, partial pattern printing (such as temperature warning labels) or full-coverage printing can be achieved to facilitate personalized designs.
[0088] The existing thermochromic layer 120 can be bonded to the outer surface of the substrate layer 110 by hot pressing, which is beneficial for distributing and controlling the material quality, and can be bonded to certain areas of the substrate layer 110 as needed.
[0089] Specifically, a thermosensitive color-changing layer 120 can be applied to a portion of the outer surface of the substrate layer 110 by spraying, printing, or hot-pressing. For example, the thermosensitive color-changing layer 120 can be applied to temperature monitoring blind spots such as Balsa wood core, PET core material, and resin-rich areas.
[0090] In one embodiment, such as Figure 1 As shown, the bag film 100 also includes a protective layer 130, which is applied to the outer surface of the thermosensitive color-changing layer 120.
[0091] In actual use, the surface of the film 100 may be scratched by tools or other parts. By setting a protective layer 130 on the outer surface of the thermochromic layer 120, the thermochromic layer 120 is prevented from being directly worn and scratched, thereby maintaining the integrity and performance of the thermochromic layer 120.
[0092] Specifically, the protective layer 130 can be made of polyester film, polypropylene film, polyurethane coating, etc. In this embodiment, no specific restrictions are placed on the material type of the protective layer 130.
[0093] In one embodiment, such as Figure 2 As shown, the thermochromic layer 120 and the substrate layer 110 are formed into a bag film 100 by multi-layer co-extrusion, and the thermochromic layer 120 is embedded in the substrate layer 110.
[0094] Multi-layer co-extrusion allows the thermo-sensitive color-changing layer 120 and the substrate layer 110 to fuse together at the molecular level, forming a tight whole. This significantly improves the adhesion between the two layers and effectively prevents the thermo-sensitive color-changing layer 120 from peeling or flaking during use, ensuring the stability and integrity of the bag film structure.
[0095] During the multi-layer co-extrusion process, the thermosensitive color-changing layer 120 can be uniformly embedded in the substrate layer 110, avoiding local over-thickness or under-thinness, ensuring the consistency and stability of the thermosensitive color-changing function on the entire surface of the bag film 100, so that the bag film 100 can accurately sense the temperature and show the corresponding color change at different positions.
[0096] The thermochromic layer 120 is embedded within the substrate layer 110. The substrate layer 110 provides physical protection for the thermochromic layer 120, shielding it from direct environmental influences such as abrasion, scratches, ultraviolet radiation, and chemical corrosion. This helps maintain the performance of the thermochromic layer 120, extends its service life, and ensures that it continues to respond accurately to temperature during long-term use.
[0097] In addition, multilayer co-extrusion is a continuous processing technology that can complete the composite of the thermosensitive color-changing layer 120 and the substrate layer 110 in one operation, which greatly improves production efficiency and reduces production costs.
[0098] In one embodiment, the substrate layer 110 is made of a thermoplastic polymer. The thermoplastic polymer may be any one of nylon, polyethylene, ethylene-vinyl acetate copolymer, or polyester.
[0099] Nylon has excellent mechanical strength and abrasion resistance, and the bags made from it can withstand greater tensile and frictional forces without easily breaking or being damaged.
[0100] Polyethylene has high chemical stability and is not easily corroded. It also has good transparency, so the wind turbine blades inside the bag 100 can be clearly seen. When the color of the bag 100 changes, the operator can technically observe the color change.
[0101] Ethylene-vinyl acetate copolymer has good elasticity and flexibility, and can quickly and firmly seal during the heat sealing process, forming a good sealing effect and preventing leakage of the bag film 100. At the same time, the heat sealing strength is high, which can ensure the sealing and integrity of the bag film 100 during use.
[0102] Polyester has extremely high transparency and gloss, as well as high strength, hardness and rigidity. The bag film 100 can withstand greater pressure and weight, is not easily deformed, and can provide reliable support and protection for the items inside the bag film 100.
[0103] In one embodiment, the thickness of the substrate layer 110 is 30μm-150μm.
[0104] When the thickness of the substrate layer 110 is greater than 30μm, it can provide sufficient structural support for the bag film 100, giving it good tensile strength and tear resistance, making it less prone to breakage or damage during use, and able to withstand items of a certain weight and a certain degree of external pressure and friction. A thickness not exceeding 150μm ensures that the bag film 100 does not become too rigid and brittle due to excessive thickness, maintaining good flexibility and folding resistance, facilitating folding and sealing operations, and also cushioning energy through deformation when subjected to external forces, reducing the risk of breakage.
[0105] The terms "upper" and "lower" are used to describe the relative positions of the various structures in the accompanying drawings. They are only for clarity of description and are not intended to limit the scope of implementation of this application. Any changes or adjustments to the relative positions without substantially altering the technical content shall also be considered within the scope of implementation of this application.
[0106] It should be noted that, in this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0107] Furthermore, in this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0108] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A vacuum-filled bag-film structure for wind turbine blades, characterized in that, include: At least one bag film (100), the bag film (100) includes a substrate layer (110) and a thermo-sensitive color-changing layer (120), the thermo-sensitive color-changing layer (120) is disposed on the substrate layer (110) or embedded in the substrate layer (110); The thermochromic layer (120) is configured to change color in response to temperature changes, and is used to monitor local temperature anomalies during the vacuum injection process of wind turbine blades. When the temperature in the area covered by the thermochromic layer (120) exceeds a preset threshold, the thermochromic layer (120) changes from a first color to a second color, and the first color and the second color are different.
2. The vacuum-filled bag-film structure for wind turbine blades according to claim 1, characterized in that, The thermochromic layer (120) is a reversible thermochromic layer. When the surface temperature of the area covered by the thermochromic layer (120) decreases from a state exceeding the preset threshold to a state below the preset threshold, the color of the area covered by the thermochromic layer (120) changes from the second color to the first color.
3. The vacuum-filled bag membrane structure for wind turbine blades according to claim 1, characterized in that, The thermochromic layer (120) is an irreversible thermochromic layer. When the surface temperature of the area covered by the thermochromic layer (120) decreases from a state exceeding the preset threshold to a state below the preset threshold, the color of the area covered by the thermochromic layer (120) remains the second color.
4. The vacuum-filled bag-film structure for wind turbine blades according to claim 1, characterized in that, At least two bags (100) are provided, and at least two bags (100) are sequentially fitted together; Wherein, at least one of the thermochromic layers (120) of the bag film (100) is a reversible thermochromic layer, and at least one of the thermochromic layers (120) of the bag film (100) is an irreversible thermochromic layer.
5. The vacuum-filled bag membrane structure for wind turbine blades according to any one of claims 1 to 4, characterized in that, The thermosensitive color-changing layer (120) is disposed on the outer surface of the substrate layer (110).
6. The vacuum-filled bag-film structure for wind turbine blades according to claim 5, characterized in that, The thermochromic layer (120) is applied to the outer surface of the substrate layer (110) by spraying, printing or hot pressing.
7. The vacuum-filled bag-film structure for wind turbine blades according to claim 5, characterized in that, The bag film (100) also includes a protective layer (130) which is applied to the outer surface of the thermosensitive color-changing layer (120).
8. The vacuum-filled bag membrane structure for wind turbine blades according to any one of claims 1 to 4, characterized in that, The thermo-sensitive color-changing layer (120) and the substrate layer (110) are formed into the bag film (100) by multi-layer co-extrusion, and the thermo-sensitive color-changing layer (120) is embedded in the substrate layer (110).
9. The vacuum-filled bag membrane structure for wind turbine blades according to any one of claims 1 to 4, characterized in that, The material of the substrate layer (110) is a thermoplastic polymer.
10. The vacuum-filled bag-film structure for wind turbine blades according to claim 9, characterized in that, The thickness of the substrate layer (110) is 30μm-150μm.