Vacuum drying device and method for cork wood of wind power blade

Abstract

The invention belongs to the technical field of wind power blade dehumidification, and discloses a wind power blade balsa wood vacuum drying device and method.The wind power blade balsa wood vacuum drying device comprises a drying room, a vacuum bag, an air heater, a one-way valve and a vacuum pump, and the vacuum bag is arranged in the drying room and is configured to wrap balsa wood in a sealed mode; the air heater is arranged in the drying room and used for providing hot air into the vacuum bag; one end of the one-way valve is connected with the air heater, and the other end of the one-way valve is hermetically connected with the vacuum bag; the vacuum pump is arranged outside the drying room, connected with the end, away from the one-way valve, of the vacuum bag in a sealed mode and used for exhausting air in the vacuum bag so that a negative pressure state can be formed in the vacuum bag and exhausting air in the vacuum bag. The drying efficiency of water vapor in the balsa wood can be improved, the phenomenon that balsa wood is white due to air filaments is reduced, the processing cost is reduced, and energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of dehumidification of wind turbine blades, and particularly to a light wood vacuum drying device and method for wind turbine blades. Background Art

[0002] In the manufacturing process of wind turbine blades, balsa wood is widely used as the core material of the core material system due to its excellent specific strength, good shear resistance and excellent processability. It forms the sandwich structure of the wind turbine blade and is embedded between the glass fiber composite skins. Usually, the vacuum infusion process is used to combine it with resin to form a composite beam with high stiffness and low weight, which is used in the main beam structure of the wind turbine blade.

[0003] With the continuous increase of the blade size, the requirement for the thickness of the balsa wood core also increases accordingly. However, with the continuous increase of the balsa wood thickness, it is difficult to completely dry the moisture inside the thicker balsa wood; and the amount of resin absorbed by it and the heat released during the curing process also increase. During the curing heat release stage, the residual moisture in the balsa wood is further evaporated. Due to the large temperature difference between the upper and lower parts of the mold, the water vapor is difficult to be discharged in time, resulting in the balsa wood filaments turning white.

[0004] Currently, usually by extending the drying time of the balsa wood, increasing the drying temperature and increasing the mold dehumidification time, the defect of the balsa wood filaments turning white is reduced. However, the above methods increase the energy consumption and extend the shell forming time to a certain extent, thereby affecting the production efficiency and increasing the processing cost. Summary of the Invention

[0005] The purpose of the present invention is to provide a light wood vacuum drying device and method for wind turbine blades, so as to improve the drying efficiency of the water vapor inside the balsa wood, reduce the phenomenon of the balsa wood filaments turning white, reduce the processing cost and reduce the energy consumption.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] A light wood vacuum drying device for wind turbine blades, comprising:

[0008] A drying room;

[0009] A vacuum bag, which is placed in the drying room and is configured to seal and wrap the balsa wood;

[0010] A hot air blower, which is arranged in the drying room and is used to provide hot air into the vacuum bag;

[0011] A one-way valve, one end of which is connected to the hot air blower, and the other end of which is hermetically connected to the vacuum bag, and is used to control the one-way entry of the hot air into the vacuum bag;

[0012] A vacuum pump is placed outside the drying chamber and is hermetically connected to one end of the vacuum bag away from the one-way valve, for evacuating the vacuum bag to form a negative pressure state inside the vacuum bag and for pumping out the air inside the vacuum bag.

[0013] Further, a plurality of vacuum bags are provided, and the plurality of vacuum bags are connected in series and hermetically. The intake ends of the plurality of vacuum bags connected in series are hermetically connected to the output end of the one-way valve, and the exhaust ends of the plurality of vacuum bags connected in series are hermetically connected to the suction end of the vacuum pump.

[0014] Further, the plurality of vacuum bags connected in series are arranged in an array inside the drying chamber.

[0015] Further, connection joints for defining the air flow direction are provided on both sides of each vacuum bag. The one-way valve and the vacuum bag, adjacent vacuum bags, and between the vacuum bag and the vacuum pump can all be hermetically connected through the connection joints.

[0016] Further, the light wood vacuum drying device for wind turbine blades further includes a pressure detection member, and the pressure detection member is arranged between the one-way valve and the vacuum bag.

[0017] Further, the light wood vacuum drying device for wind turbine blades further includes a buffer tank. The buffer tank is arranged outside the drying chamber. The input end of the buffer tank is hermetically connected to the output end of the vacuum bag, and the output end of the buffer tank is hermetically connected to the suction end of the vacuum pump, for storing condensed water.

[0018] Further, the light wood vacuum drying device for wind turbine blades further includes a plurality of connecting pipes. The one-way valve, the pressure detection member, the vacuum bag, the buffer tank, and the vacuum pump are sequentially hermetically connected through the connecting pipes.

[0019] Further, the light wood vacuum drying device for wind turbine blades further includes a plurality of sealing members. The plurality of sealing members are respectively arranged at both ends of each connecting pipe, for ensuring the sealing performance of the connection of the connecting pipes.

[0020] Further, the sealing member is a sealing ring.

[0021] A method for vacuum drying light wood of wind turbine blades, using the light wood vacuum drying device as described in any one of the above, includes the following steps:

[0022] S1: After hermetically wrapping the balsa wood with the vacuum bag, transport it into the drying chamber;

[0023] S2: sequentially connecting the output end of the hot air blower to the input end of the one-way valve, the output end of the one-way valve to the input end of the vacuum bag, the output end of the vacuum bag to the vacuum pump, and the vacuum pump is placed outside the drying room;

[0024] S3: before drying begins, the hot air blower, the one-way valve and the vacuum pump are turned on in sequence to form a negative pressure environment inside the vacuum bag;

[0025] S4: drying the balsa wood in the vacuum bag by hot air under the negative pressure environment to quickly evaporate the water inside the balsa wood;

[0026] S5: After the drying is completed, the one-way valve connected to the hot air blower is closed in sequence, the vacuum pump is turned off, and the balsa wood wrapped in the vacuum bag after drying is taken out from the drying room.

[0027] Beneficial effects of the present invention:

[0028] The present invention provides a wind turbine blade balsa wood vacuum drying device and method, including a drying room, a vacuum bag, a hot air blower, a one-way valve and a vacuum pump. By placing the balsa wood in a vacuum bag for transportation and drying, the contact between the balsa wood and moisture in the air during transportation and drying can be effectively reduced, so that the balsa wood is in a sealed state before, during and after drying to avoid moisture absorption, thereby significantly shortening the drying time. During the drying process, the hot air blower, the one-way valve, the vacuum bag and the vacuum pump are sealed and connected in sequence, and the hot air is introduced into the vacuum bag through the one-way valve to heat the balsa wood. At the same time, the vacuum pump continuously extracts the air in the bag and the water vapor generated by evaporation; when the vacuum pump is running to form a negative pressure environment in the bag, the boiling point of the water in the balsa wood is significantly reduced, so that it can evaporate rapidly at a lower temperature. This not only avoids the deformation or carbonization of the balsa wood caused by high temperature, but also facilitates the migration of water outward in a vacuum environment to prevent it from remaining inside, thereby improving the drying uniformity and efficiency. In addition, since it is no longer necessary to heat the balsa wood to 100°C, effective dehydration can be achieved, the overall energy consumption is reduced, and the operating costs are reduced accordingly, ultimately achieving efficient and rapid drying of the balsa wood, effectively reducing the whitening defect caused by water vapor retention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the balsa wood vacuum drying device for wind turbine blades in the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of the vacuum bag in the present invention.

[0031] In the figure:

[0032] 100. Balsa wood;

[0033] 1. Baking room; 2. Vacuum bag; 3. Hot air blower; 4. Check valve; 5. Vacuum pump; 6. Connecting joint; 7. Pressure detector; 8. Buffer tank; 9. Connecting pipe. Detailed implementation manners

[0034] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings, rather than all structures.

[0035] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above the top of", and "on the top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is at a higher horizontal height than the second feature. The first feature being "below", "below the bottom of", and "under the bottom of" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is at a lower horizontal height than the second feature.

[0037] In the description of this embodiment, the orientation or positional relationship terms such as "above", "below", "left", and "right" are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0038] Please refer to Figures 1 to 2The present embodiment provides a wind turbine blade balsa wood vacuum drying device, comprising a drying room 1, a vacuum bag 2, a hot air blower 3, a one-way valve 4 and a vacuum pump 5, wherein the vacuum bag 2 is placed in the drying room 1 and is configured to seal and wrap the balsa wood 100; the hot air blower 3 is arranged in the drying room 1, and is used to provide hot air into the vacuum bag 2; one end of the one-way valve 4 is connected to the hot air blower 3, and the other end thereof is sealedly connected to the vacuum bag 2, and is used to control the one-way entry of hot air into the vacuum bag 2; the vacuum pump 5 is placed outside the drying room 1, and is sealedly connected to one end of the vacuum bag 2 away from the one-way valve 4, and is used to evacuate the vacuum bag 2 to form a negative pressure state inside the vacuum bag 2, and is used to evacuate the air in the vacuum bag 2.

[0039] By placing the balsa wood 100 in a vacuum bag 2 for transportation and drying, the contact between the balsa wood 100 and the moisture in the air during transportation and drying can be effectively reduced, so that the balsa wood 100 is in a sealed state before, during and after drying to avoid moisture absorption, thereby significantly shortening the drying time. During the drying process, the hot air blower 3, the one-way valve 4, the vacuum bag 2 and the vacuum pump 5 are sealed and connected in sequence, and the hot air is introduced into the vacuum bag 2 through the one-way valve 4 to heat the balsa wood 100. At the same time, the vacuum pump 5 continuously extracts the air in the bag and the water vapor generated by evaporation; according to the principles of thermodynamics, the boiling of water occurs when its vapor pressure is equal to the ambient pressure; when the vacuum pump 5 is running to form a negative pressure environment in the bag, the boiling point of the water in the balsa wood 100 is significantly reduced, so that it can evaporate rapidly at a lower temperature. This not only avoids the deformation or carbonization of the balsa wood 100 caused by high temperature, but also facilitates the migration of water outward in a vacuum environment to prevent it from remaining inside, thereby improving the uniformity and efficiency of drying. In addition, since it is no longer necessary to heat the balsa wood 100 to 100°C, effective dehydration can be achieved, the overall energy consumption is reduced, and the operating costs are reduced accordingly, ultimately achieving efficient and rapid drying of the balsa wood 100, effectively reducing the whitening defect of the air fibers caused by water vapor retention.

[0040] In some optional embodiments, a plurality of vacuum bags 2 are provided, and the plurality of vacuum bags 2 are sealed and connected in series, the air inlet ends of the plurality of vacuum bags 2 connected in series are sealed and connected to the output ends of the one-way valve 4, and the air outlet ends of the plurality of vacuum bags 2 connected in series are sealed and connected to the exhaust end of the vacuum pump 5; wherein, after the plurality of vacuum bags 2 are connected in series, the plurality of vacuum bags 2 connected in series are sealed and connected to each other, thereby forming a closed vacuum system, and under the premise of unified exhaust, the negative pressure state in each vacuum bag 2 can be kept basically consistent, and a plurality of balsa woods 100 can be processed at the same time, realizing batch and continuous drying operations, further improving the drying efficiency, and at the same time helping to achieve uniform drying, avoiding local moisture residue or uneven drying due to unstable negative pressure, and ensuring the drying quality.

[0041] Specifically, multiple series-connected vacuum bags 2 are arranged in an array within the drying chamber 1. This design can make full use of the internal space of the drying chamber 1, enabling multiple vacuum bags 2 to be compactly and orderly arranged within a limited area, avoiding chaos or space waste. Moreover, the array structure helps the hot air to flow regularly within the drying chamber 1, and the air flow can more evenly surround each vacuum bag 2, improving the consistency of heat reception of each vacuum bag 2 and avoiding the phenomenon of uneven drying caused by insufficient or excessive temperature in some areas.

[0042] As Figure 2 shown, more specifically, connection joints 6 with the function of defining the air flow direction are provided on both sides of each vacuum bag 2. The one-way valve 4, between adjacent vacuum bags 2, and between the vacuum bag 2 and the vacuum pump 5 can all be hermetically connected through the connection joints 6. Among them, by providing connection joints 6 with the function of defining the air flow direction on both sides of each vacuum bag 2, it can ensure that the air flow can only flow in a predetermined direction, avoiding the backflow of hot air or water vapor and improving the drying efficiency. And each structure can be hermetically connected, ensuring the continuous and stable operation of the device under a negative pressure state. Among them, the connection joint 6 can be, but is not limited to, a joint with a check valve, and no specific limitation is made here.

[0043] Optionally, seals such as silica gel rings or rubber rings can be provided between each structure for sealing.

[0044] As Figure 1 shown, in this embodiment, the light wood vacuum drying device for wind turbine blades further includes a pressure detection member 7, which is arranged between the one-way valve 4 and the vacuum bag 2. Among them, by providing this pressure detection member 7, the operator can monitor the pressure state inside the device in real time. And the air supply volume of the hot air blower 3 and the air extraction intensity of the vacuum pump 5 can be adjusted in combination with the actual situation of the light wood 100 to be dried and the measured pressure value, so as to achieve more accurate and efficient drying control.

[0045] Optionally, the pressure detection member 7 can be, but is not limited to, including a pressure gauge, etc., and no specific limitation is made here.

[0046] To prevent the evaporated water vapor from condensing into water due to pre-cooling after leaving the drying chamber 1 and entering the air suction end of the vacuum pump 5 to cause damage after accumulating a certain amount, the light balsa wood vacuum drying device for wind turbine blades further includes a buffer tank 8. The buffer tank 8 is arranged outside the drying chamber 1. The input end of the buffer tank 8 is hermetically connected to the output end of the vacuum bag 2, and the output end of the buffer tank 8 is hermetically connected to the air suction end of the vacuum pump 5 for storing condensed water. Among them, by arranging the buffer tank 8 between the vacuum pump 5 and the vacuum bag 2 outside the drying chamber 1, the condensed water formed after the water vapor flowing out of the drying chamber 1 is cooled can be preferentially deposited in the buffer tank 8, avoiding it directly entering the vacuum pump 5, thereby preventing the vacuum pump 5 from being corroded or damaged due to inhaling water vapor, effectively prolonging the service life and operation stability of the vacuum pump 5, and improving the reliability and continuous operation ability of the entire drying system.

[0047] In some embodiments, the light balsa wood vacuum drying device for wind turbine blades further includes a plurality of connecting pipes 9. The check valve 4, the pressure detection member 7, the vacuum bag 2, the buffer tank 8 and the vacuum pump 5 are sequentially hermetically connected through the connecting pipes 9. Among them, the connecting pipes 9 can make the components of each part compactly combined and reasonably arranged, facilitating the assembly, adjustment and maintenance of the overall device.

[0048] Furthermore, the light balsa wood vacuum drying device for wind turbine blades further includes a plurality of seals, and the plurality of seals are respectively arranged at both ends of each connecting pipe 9 to ensure the sealing performance of the connection of the connecting pipe 9. Among them, by arranging seals at both ends of each connecting pipe 9, it can effectively prevent hot air or water vapor from leaking at the connection, further improving the airtightness of the device and ensuring the stability of the vacuum environment during the drying process. And, the good sealing performance can prevent external air from entering the device, avoiding the decrease of the vacuum degree caused by leakage, thus affecting the evaporation efficiency of the moisture inside the light balsa wood 100.

[0049] Optionally, the seal can be but is not limited to an O-ring, etc., and no specific limitation is made here.

[0050] This embodiment provides a method for vacuum drying light balsa wood of wind turbine blades, using the light balsa wood vacuum drying device in any of the above embodiments, including the following steps:

[0051] S1: After hermetically wrapping the light balsa wood 100 with the vacuum bag 2, transport it into the drying chamber 1;

[0052] S2: Connect the output end of the hot air blower 3 to the input end of the check valve 4, the output end of the check valve 4 to the input end of the vacuum bag 2, the output end of the vacuum bag 2 to the vacuum pump 5 in sequence, and place the vacuum pump 5 outside the drying chamber 1;

[0053] S3: Before starting the drying, turn on the hot air blower 3, the check valve 4 and the vacuum pump 5 in sequence to make a negative pressure environment inside the vacuum bag 2;

[0054] S4: Under a negative pressure environment, use hot air to dry the balsa wood 100 in the vacuum bag 2, causing the moisture inside to rapidly evaporate.

[0055] S5: After drying is completed, sequentially close the one-way valve 4 connected to the hot air blower 3, turn off the vacuum pump 5, and take out the dried balsa wood 100 wrapped in the vacuum bag 2 from the drying chamber 1.

[0056] By using the vacuum bag 2 to tightly wrap the balsa wood 100, during the entire process of transportation, drying, and after drying, it can effectively isolate the balsa wood 100 from contact with external moisture, prevent moisture absorption and rehumidification, keep the balsa wood 100 in a sealed state at all times, avoid moisture absorption, thus significantly shortening the drying time and ensuring a long-term dry state after meeting the drying standard. By establishing a negative pressure environment inside the device with the vacuum pump 5, the air pressure inside the vacuum bag 2 is lower than the atmospheric pressure, thereby significantly reducing the boiling point of water, enabling the water to rapidly evaporate at a lower temperature. This process not only improves the drying speed and uniformity, reduces energy consumption, but also avoids thermal damage such as carbonization or deformation of the balsa wood 100 caused by high temperatures. At the same time, it helps the full migration and release of deep moisture inside the balsa wood 100, improving the overall drying quality. At the end of the drying stage, by sequentially closing the hot air blower 3 and the vacuum pump 5, and evacuating most of the moisture before that, it effectively prevents the backflow of hot air and the reverse flow of condensed water, avoiding thermal shock or damage to the equipment. This method executes the processes of heating, air extraction, and negative pressure formation step by step, with a clear structure and a clear control logic. It is suitable for automated system control, facilitating precise adjustment of temperature, pressure, and drying time, improving production efficiency, and reducing the risk of errors caused by human intervention; adopting the vacuum drying principle of combining "hot air + negative pressure", while ensuring the drying efficiency, effectively reducing quality problems such as white filaments in the balsa wood 100, and reducing energy consumption and processing costs. At the same time, since the dried balsa wood 100 remains wrapped in the vacuum bag 2, avoiding re-moisture absorption, the traditional shell dehumidification process can be cancelled, shortening the mold occupation time, and further improving the shell forming efficiency.

[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A balsa vacuum drying device for wind turbine blades, characterized in that Comprising: A drying chamber (1); A vacuum bag (2), which is placed inside the drying chamber (1) and is configured to seal and wrap the balsa wood (100); A hot air blower (3), which is arranged inside the drying chamber (1) and is used to supply hot air into the vacuum bag (2); A one-way valve (4), one end of which is connected to the hot air blower (3) and the other end of which is hermetically connected to the vacuum bag (2), and is used to control the unidirectional entry of the hot air into the vacuum bag (2); A vacuum pump (5), which is placed outside the drying chamber (1) and is hermetically connected to one end of the vacuum bag (2) away from the one-way valve (4), and is used to evacuate the vacuum bag (2) to form a negative pressure state inside the vacuum bag (2) and is used to extract the air inside the vacuum bag (2).

2. The light wood vacuum drying device for wind power blades according to claim 1, wherein, A plurality of the vacuum bags (2) are provided, and the plurality of vacuum bags (2) are connected in series and hermetically, the intake ends of the plurality of serially connected vacuum bags (2) are hermetically connected to the output end of the one-way valve (4), and the exhaust ends of the plurality of serially connected vacuum bags (2) are hermetically connected to the suction end of the vacuum pump (5).

3. The light wood vacuum drying device for wind turbine blades according to claim 2, characterized in that, The plurality of serially connected vacuum bags (2) are arranged in an array inside the drying chamber (1).

4. The light wood vacuum drying device for wind power blades according to claim 3, characterized in that On both sides of each vacuum bag (2), there are provided connection joints (6) that define the air flow direction, and the one-way valve (4) and the vacuum bag (2), adjacent vacuum bags (2), and between the vacuum bag (2) and the vacuum pump (5) can all be hermetically connected through the connection joints (6).

5. The light wood vacuum drying device for wind power blades according to any one of claims 1-4, characterized in that, The balsa wood vacuum drying device for wind power blades further includes a pressure detection member (7), which is arranged between the one-way valve (4) and the vacuum bag (2).

6. The light wood vacuum drying device for wind power blades according to claim 5, characterized in that, The balsa wood vacuum drying device for wind power blades further includes a buffer tank (8), which is arranged outside the drying chamber (1), the input end of the buffer tank (8) is hermetically connected to the output end of the vacuum bag (2), and the output end of the buffer tank (8) is hermetically connected to the suction end of the vacuum pump (5), and is used to store condensed water.

7. The light wood vacuum drying device for wind power blades according to claim 6, characterized in that, The balsa wood vacuum drying device for wind power blades further includes a plurality of connecting pipes (9), and the one-way valve (4), the pressure detection member (7), the vacuum bag (2), the buffer tank (8), and the vacuum pump (5) are sequentially hermetically connected through the connecting pipes (9).

8. The light wood vacuum drying device for wind power blades according to claim 7, characterized in that The balsa wood vacuum drying device for wind power blades further includes a plurality of sealing members, and the plurality of sealing members are respectively arranged at both ends of each connecting pipe (9) to ensure the sealing performance of the connection of the connecting pipe (9).

9. The light wood vacuum drying device for wind power blades according to claim 8, characterized in that, The sealing member adopts a sealing ring.

10. The method for vacuum drying balsa wood of a wind turbine blade is characterized in that Using the balsa wood vacuum drying device for wind power blades according to any one of claims 1-9, comprising the following steps: S1: After the balsa wood (100) is hermetically wrapped by the vacuum bag (2), it is transported into the drying chamber (1); S2: Connect the output end of the hot air blower (3) to the input end of the one-way valve (4) in sequence, connect the output end of the one-way valve (4) to the input end of the vacuum bag (2), connect the output end of the vacuum bag (2) to the vacuum pump (5), and place the vacuum pump (5) outside the drying chamber (1). S3: Before the drying starts, turn on the hot air blower (3), the one-way valve (4) and the vacuum pump (5) in sequence to create a negative pressure environment inside the vacuum bag (2). S4: Under the negative pressure environment, use hot air to dry the balsa wood (100) inside the vacuum bag (2) to quickly evaporate the moisture inside it. S5: After the drying is completed, close the one-way valve (4) connected to the hot air blower (3) in sequence, turn off the vacuum pump (5), and take out the balsa wood (100) wrapped around the vacuum bag (2) after drying from the drying chamber (1).

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