Congelation disaster resisting system of hectometer-level blade wind turbine generator and control method

Abstract

The invention discloses an anti-congelation disaster system of a hectometer-level blade wind turbine generator and a control method, and the anti-congelation disaster system of the hectometer-level blade wind turbine generator comprises a wind turbine generator blade, and a heating unit and an anti-shearing web plate which are arranged on the wind turbine generator blade, the heating unit comprises an air blower close to the anti-shearing web, an air duct heater and a heat conduction pipe, the air blower and the air duct heater are close to the root, the heat conduction pipe is arranged along the anti-shearing web, and the air blower, the air duct heater and the heat conduction pipe are in fluid communication; air blown out of the air blower flows out of the air outlet end of the heat conduction pipe after passing through the air duct heater and the heat conduction pipe. According to the anti-congelation system of the hectometer-level blade wind turbine generator, hot air provided by the air duct heater can be directly conveyed to the upper middle portion of the blade, the heating effect of the blade tip section of the blade is improved, and therefore the phenomenon that due to congelation and freezing of the blade of the wind turbine generator, the overall pneumatic performance of the blade is reduced, and the generator set stops running is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind power generation, and relates to an anti-freezing system and control method for a 100-meter-class blade wind turbine set, and specifically to an active gas-heating anti-icing / de-icing system and control method for a 100-meter-class blade wind turbine set to resist freezing disasters. Background Art

[0002] In my country's humid and freezing areas such as the Yunnan-Guizhou Plateau, Hunan, and Sichuan, wind turbines in the region frequently stop operating due to blade icing during the freezing period each year, resulting in huge losses in annual power generation at wind farms. Statistical studies have shown that freezing disasters in some wind farms in my country's most severely frozen areas have caused power generation losses of up to 10%, greatly affecting the economic benefits of wind energy development and the utilization of new energy resources. Therefore, wind turbine anti-freezing disasters have become a major production and technical problem that needs to be urgently solved by wind power owners and maintenance managers in the region.

[0003] With the continuous development of wind power technology and the continuous increase in single-unit capacity, wind turbines with a capacity of 5MW and above have gradually begun to occupy the newly developed wind power market in areas such as the Yunnan-Guizhou Plateau, and will become the main force in wind energy development in the region.

[0004] Since the development of wind turbine anti-freezing technology, various wind turbine anti-freezing methods have been continuously researched and tested. Studies have shown that active gas heating anti-freezing technology is most suitable for wind turbines in humid freezing environments. Its basic solution is: a customized air duct heater is installed on each blade at the root of the blade leading edge. After heating the air, a high-performance blower is used to transport it to the upper and middle part of the blade leading edge (approximately 1 / 3 of the blade length (wind deflector position) above) to continuously heat the composite blade body, so that the surface temperature of each wind turbine blade is maintained above 0°C during the winter freezing period to achieve the purpose of blade surface anti-freezing. The three blades have the same internal heating system, equipment selection, and installation layout. Each blade heating system is equipped with an independent power control box and signal detection box, which are installed on the outer surface of the corresponding blade hub.

[0005] Active aerothermal technology for wind turbine anti-icing has been successfully tested on a 2MW wind turbine (with blades approximately 50m long). A May 2024 paper published in the journal Renewable Energy, "2MW Wind Turbine Blade Anti-icing Test and Energy Consumption Assessment," indicates that the commonly used active aerothermal technology can successfully protect 2MW wind turbines from freezing hazards, consuming less than 50kW of heating power and achieving ideal anti-icing and de-icing results at an ambient temperature of -5°C.

[0006] With the current mainstream installation of 5MW wind turbines (97m blades), it is difficult to achieve ideal anti-freezing disaster protection using anti-freezing disaster systems similar to those used for 2MW wind turbines. The main reason is that the blades are 100m long or longer. Previous research has pointed out that the de-icing system for wind turbines with blades longer than 60m faces a power bottleneck. Similarly, field tests of a similar design for the active gas-heating anti-freezing disaster system for 5MW wind turbine blades at a certain wind farm showed that the design of the anti-freezing disaster system for wind turbines with blades longer than 60m is significantly different from that for wind turbines with blades of 50m or less, and no longer meets the technical requirements of current industry applications. Therefore, there is an urgent need to solve the design and operation control methods of the anti-freezing disaster system for wind turbines with blades of 100m. At the same time, it is also necessary to simplify the system structure, improve the system's operational reliability, and reduce the safety risks of equipment operation. Summary of the Invention

[0007] The purpose of the present invention is to provide a 100-meter-class blade wind turbine anti-freezing disaster system and control method to solve the problems existing in the above-mentioned prior art.

[0008] In order to solve the above problems, according to one aspect of the present invention, a 100-meter-class blade wind turbine anti-freezing disaster system is provided, wherein the 100-meter-class blade wind turbine anti-freezing system includes a wind turbine blade, a heating unit and an anti-shear web arranged on the wind turbine blade, and the wind turbine blade includes a blade root and a blade tip arranged at both ends of the wind turbine blade.

[0009] One end of the anti-shear web is arranged close to the blade root and the other end of the anti-shear web extends toward the blade tip.

[0010] The heating unit includes a blower, an air duct heater and a heat conducting pipe arranged near the anti-shear web. The blower and the air duct heater are arranged near the root, and the heat conducting pipe is arranged along the anti-shear web. The blower, the air duct heater and the heat conducting pipe are fluidically connected. The air blown out from the blower passes through the air duct heater and the heat conducting pipe and then flows out from the air outlet end of the heat conducting pipe. The opening of the air outlet end of the heat conducting pipe faces the blade tip.

[0011] In one embodiment, the heat pipe is fixed on the leading edge anti-shear web, and the distance from the air outlet end of the heat pipe to the blade root is 2 / 3 of the total length of the wind turbine blade, and the total length of the wind turbine blade is the distance from the blade root to the blade tip.

[0012] In one embodiment, the wind turbine blade further includes a windshield plate arranged perpendicular to the direction from the blade root to the blade tip, and the distance from the windshield plate to the blade root is 1 / 3 of the total length of the wind turbine blade, and the total length of the wind turbine blade is the distance from the blade root to the blade tip.

[0013] In one embodiment, the anti-shear web is also provided with 5 to 10 circular holes, which are arranged on the center line of the anti-shear web. Starting from the blade tip, a circular hole with a diameter of 60-100 mm is arranged every 1-2 m, thereby increasing the heat transfer energy of the blade at the blade tip by increasing the circulation velocity and flow of high-temperature hot air.

[0014] In one embodiment, a detection unit is further provided on the wind turbine blade, and the detection unit includes a temperature sensor for controlling the gas temperature of the heating unit and a pressure sensor for the gas flow, wherein a first temperature sensor is provided on the inner wall of the blade, and the first temperature sensor is located at the air outlet end of the heat pipe, and the heat pipe is respectively provided with a second temperature sensor and a pressure sensor, and the distance between the second temperature sensor and the outlet of the air duct heater is 1-2m, and the distance between the pressure sensor and the second temperature sensor is 1-2m.

[0015] In one embodiment, the anti-freezing system of the 100-meter-class blade wind turbine also includes a control unit, which includes a blade heating power supply control device and a monitoring signal acquisition device. The blade heating power supply control device includes a power regulator for controlling and adjusting the heating power and a frequency converter for adjusting the wind pressure and air volume. The power regulator is used to control and adjust the heating power of the three air duct heaters in the three wind turbine blades, and the frequency converter is used to control and adjust the operating air volume of the three blowers in the three wind turbine blades. The monitoring signal acquisition device is used for temperature detection of the temperature sensors and pressure detection of the pressure sensors on the three wind turbine blades, respectively, and is used for centralized monitoring of the temperature and flow of the heated air in the heat pipes of the three wind turbine blades of the wind turbine.

[0016] Another aspect of the present invention provides an anti-freezing control method for a 100-meter-class blade wind turbine, which uses the above-mentioned anti-freezing system for the 100-meter-class blade wind turbine to perform anti-freezing operations, including the following steps:

[0017] Step 1: When the ambient temperature of the wind turbine is lower than 2°C, a freezing disaster prediction is performed. If any of the following conditions are met, the wind turbine anti-freezing disaster system is activated:

[0018] a. If an ice detector is installed, proceed to step 2 when the ice detector detects ice thickness of 0.1 mm or above, or proceed to step 3 when the ambient temperature is below -5°C;

[0019] b. If no ice detector is installed, go to step 2 when the ambient temperature is below 2°C and the ambient humidity is greater than 85%, or go to step 3 when the ambient temperature is below -5°C;

[0020] c. When the wind turbine stops operating due to condensation and freezing, go to step 3;

[0021] Step 2: The antifreeze system enters the anti-icing heating control working mode. When the second condition is met, the system enters step 3.

[0022] Step 3: The antifreeze system enters the de-icing heating control working mode. When the first condition is met, it enters step 2.

[0023] Step 4: The wind turbine blade heating control working mode ends.

[0024] In one embodiment, step 1 further includes a startup method, which includes:

[0025] Set the inverter frequency set value to 20 Hz, start the inverter and blower, check that the blower operates normally and continuously for 30 seconds, then start the power regulator and duct heater. The power regulator starts and controls the temperature to an initial set value of 30° C., and then adjust the control value according to the control requirements of the de-icing heating control working mode or the anti-icing heating control working mode.

[0026] In one embodiment, in step 2, the temperature range of the wind turbine blades in the anti-icing heating control working mode is 50°C to 60°C; in step 3, the temperature range of the wind turbine blades in the de-icing heating control working mode is 60°C to 80°C.

[0027] In one embodiment, in step 2, the first condition is: if an ice detector is installed, when the ice detector detects that the ice thickness is 0.1 mm or greater, or if the ice detector is not installed, when the ambient temperature is lower than 2° C. and the ambient humidity is greater than 85%;

[0028] In step 3, the second condition is: the ambient temperature of the wind turbine generator set is lower than -5°C.

[0029] In one embodiment, the heating control working mode ends by slowly adjusting the power regulator control temperature setpoint back to 30°C, shutting down the power regulator and heater, and starting to adjust the inverter control setpoint to 20Hz after 1 minute, stopping the inverter and blower, and thus ending the heating control work.

[0030] The beneficial effects of the present invention are:

[0031] 1. The heating system design for wind turbine blades (hereinafter referred to as blades) can directly deliver the high-temperature hot air heating medium and heating energy provided by the duct heater to the middle and upper part of the blade, thereby improving the anti-icing heating effect of the blade tip section (1 / 3 of the blade length) to prevent the ice formation in this section of the blade from causing a significant decrease in the overall aerodynamic performance of the blade, resulting in unit shutdown and affecting the operation and power generation of the wind farm.

[0032] 2. Regarding the unit electrical system design, the power control equipment of each blade heating system is integrated into a "three-in-one" blade heating power control device, and the installation location is moved from the front of the wind turbine hub to the wind turbine nacelle to reduce the load of additional equipment in the hub and operational safety risks. At the same time, the "one-to-three" design scheme simplifies the power system structure, reduces the number of cables, and eliminates the obstacles and construction difficulties of the power cable passing through the main shaft hole after the slip ring, thereby improving the overall power supply reliability of the blade heating of the unit's anti-freezing disaster system.

[0033] 3. Regarding the unit control system design, a "one-to-three" design scheme was also adopted to simplify the control system structure and improve operational reliability. Furthermore, a duct heater power regulator and blower inverter were used to coordinate and control blade heating temperature and forward-displace heating energy consumption, enhancing heating efficiency at the blade tip. This addressed the technical bottleneck of the active gas heating method for anti-freezing disasters in large-capacity wind turbine units with a height of 100 meters. The operational control strategy with two operating modes, designed according to the principle of "anti-icing as the primary and de-icing as the secondary," reduced the overall anti-icing and de-icing heating energy consumption of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the location of a single wind turbine blade heating device in this embodiment;

[0035] Figure 2 This is a schematic three-dimensional cross-sectional view of a single wind turbine blade heating device according to this embodiment;

[0036] Figure 3 Schematic diagram of the electrical system of the wind turbine generator set for preventing freezing disasters in this embodiment;

[0037] Figure 4 This is a schematic diagram of a control system for preventing freezing disasters of a wind turbine generator set according to this embodiment;

[0038] Figure 5 This is a schematic diagram of a control system for heating blades of a single wind turbine in this embodiment;

[0039] Figure 6 This is a schematic diagram of a control method for heating a single wind turbine blade in this embodiment. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the objects, features and advantages of the present invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0041] In the following description, for the purpose of illustrating the various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0042] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0043] In the following description, in order to clearly show the structure and working mode of the present invention, many directional words will be used for description, but words such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and should not be understood as restrictive terms.

[0044] It should be noted that the features shown in the drawings of this application may belong to one embodiment or to different embodiments, as long as there is no conflict between these features. To save space, this application may use the same drawing to illustrate different embodiments. In other words, the same drawing of this application can be used to illustrate features of different embodiments.

[0045] In order to solve the above technical problems, this embodiment provides a 100-meter-class blade wind turbine anti-freezing disaster system and a control method thereof.

[0046] A 100-meter-class blade wind turbine anti-freezing disaster system includes a heating unit, a detection unit and a control unit. The heating unit and the detection unit are arranged on the wind turbine blade. In the embodiment, a single wind turbine blade is used for description.

[0047] like Figure 1 and Figure 2As shown, the heating unit includes a blower 3, a duct heater 4, and a heat pipe 5. Starting from the blade root 1, the blower 3 and duct heater 4 are arranged closely against the shear web 2 toward the blade tip. The blower 3 and duct heater 4 are fixedly mounted on the blade near the blade root 1. The air outlet of the blower 3 is connected to the air inlet of the duct heater 4. A high-temperature composite heat pipe 5 is arranged from the air outlet of the duct heater 4 along the shear web 2 toward the blade tip until it reaches approximately 2 / 3 of the blade's length. The air inlet end of the heat pipe 5 is connected to the air outlet of the duct heater 4, with the air outlet opening facing toward the blade tip.

[0048] The detection unit includes a first temperature sensor 7, a pressure sensor 8, and a second temperature sensor 9 for controlling the temperature and flow of the air heated by the heating unit. The second temperature sensor 9 is installed on the inner wall of the blade at the outlet of the heat pipe 5. The first temperature sensor 7 is placed on the outer wall of the heat pipe 1-2 meters from the outlet of the duct heater 4 to detect the high-temperature hot air inside the heat pipe 5. A pressure sensor 8 is placed 1-2 meters apart to detect the high-temperature hot air pressure, thus forming a system that controls the operating temperature, pressure, and flow of the heated air. The signal line in the detection unit is laid along the outer wall of the high-temperature composite pipe to the blade root 1, with a 10-meter reserve.

[0049] At a position about 1 / 3 of the blade length away from the blade root 1, a high-strength composite material windshield 6 is set to block the high-temperature hot air from flowing back to the blade root 1, forming a continuously heated closed space in the direction of the blade tip. Under the action of the blower 3, the high-temperature hot air is forced to circulate in the blade leading edge channel, continuously heating the heavy ice area from the middle and upper part of the blade to the leading edge of the blade tip; on the centerline of the shear web 2, a plurality of circular holes 10 with a diameter of 60-100mm are set at intervals of 1-2m from the blade tip, and 5 to 10 holes are preferably set to increase the ventilation area between the leading and trailing edges of the blade, thereby increasing the heat transfer energy of the blade at the blade tip by increasing the circulation velocity and flow of the high-temperature hot air.

[0050] The control unit includes a blade heating power supply control device and a monitoring signal acquisition device. The blade heating power supply control device includes a power regulator and a frequency converter for controlling and adjusting the blade heating energy consumption. The power regulator is used to control and adjust the heating power of the duct heater, and the frequency converter is used to control and adjust the blower operating air volume.

[0051] In the embodiment, Figure 3The electrical system of a wind turbine anti-freezing disaster system shown in the figure uses a single power regulator to control the heating power of three duct heaters within three blades, and a single frequency converter to control the air volume of three blowers. The nacelle blade heating power control unit, which includes a power regulator and frequency converter, is installed in a suitable location within the turbine nacelle. A 690V power supply is connected from the high-voltage side of the dry-type transformer at the base of the wind turbine tower to the heater power regulator input terminal of the blade heating power control unit in the nacelle. A 380V power supply is connected from the existing nacelle control cabinet to the blower frequency converter input terminal of the blade heating power control unit. The 690V power and 380V frequency power outputs from the nacelle blade heating power control unit are routed through the turbine slip ring to the main shaft bore and then into the nacelle hub. In the wheel hub, a 690V power supply is split into three parts and connected to three blade duct heaters. A 380V frequency-modulated power supply is split into three parts and connected to three blade blowers. A power regulator within the nacelle blade heating power control unit simultaneously controls the operation of the three duct heaters, while a frequency converter controls the operation of the three blowers. The power regulator maintains constant temperature control of the hot air at the outlet of the three duct heaters, while a frequency converter controls the outlet pressure of the three blowers.

[0052] like Figure 4 The control system portion of the wind turbine anti-freezing disaster system shown in the figure. The detection signals from the temperature and pressure sensors within each blade are connected via signal coaxial cables to a PLC (programmable logic controller) in the monitoring signal acquisition device within the nacelle hub for centralized management. The communication cable passes through the main shaft hole and the wind turbine slip ring, connecting to the communication interface at the input of the industrial switch within the nacelle blade heating power supply control device, enabling centralized collection and transmission of nine blade monitoring signals. One output port of the industrial switch is connected via a network cable to the communication network port within the wind turbine nacelle, completing the communication network connection with the wind turbine anti-freezing disaster monitoring platform in the 110kV booster station central control room, enabling remote control and telemetry of the unit's anti-freezing disaster system operation.

[0053] like Figure 5The control system for a single blade heating system is shown in the figure. The fan inverter and power regulator (stepless power regulator) are located within the nacelle blade heating power supply control unit. The temperature and pressure of the hot air in the heat transfer pipe at the outlet of each blade's heater are independently controlled. The temperature parameter is controlled by the stepless power regulator to control the duct heater, while the pressure parameter is controlled by the inverter to control the blower. The temperature signal detected by the temperature sensor at the outlet of the duct heater is transformed, and a single closed-loop control system is constructed with the stepless power regulator in the blade heating power supply control device to achieve constant temperature control and adjustment of the high-temperature hot air temperature of the heat pipe; the pressure signal detected by the pressure sensor at the outlet of the duct heater is transformed, and a single closed-loop control system is constructed with the fan frequency converter in the blade heating power supply control device to achieve constant pressure control and adjustment of the high-temperature hot air pressure of the heat pipe; the temperature signal detected by the temperature sensor in the direction of the tip of each blade is only used for temperature monitoring and judgment of the heated air in the middle and upper part of the blade. If the temperature is low, the temperature can be increased by increasing the blower operating speed or the duct heater power, thereby ensuring the anti-freezing disaster effect of the wind turbine in real time.

[0054] The detection values of the temperature sensor and pressure sensor at the outlet of the heater in the three blades are respectively used to construct a single closed-loop constant temperature control system and a constant pressure control system with the power regulator and the frequency converter.

[0055] The embodiment also provides a method for controlling anti-freezing disasters of a 100-meter-class blade wind turbine, including the following operation control strategy, operation steps, and start-stop method:

[0056] 1. Operation control strategy

[0057] (1) Operation control strategy of wind turbine anti-freezing disaster system, its working modes are divided into two types:

[0058] The first working mode: blade anti-icing heating control working mode, the blade heating control temperature is in the range of 50℃ ~ 60℃.

[0059] The second working mode: blade de-icing heating control working mode, the blade heating control temperature is in the range of 60℃~80℃.

[0060] (2) To ensure the safety of the blade equipment itself during the heating process, the upper limit of the blade heating control temperature in the second working mode is 80°C, and the upper limit of the blower inverter operating frequency is 50Hz. The icing status of the unit blades and the power output are judged. When the unit is severely frozen, the blade heating temperature and blower operating frequency should be increased in real time to improve the heating effect of the blade tip.

[0061] (3) During the anti-freezing disaster process of the wind turbine, the anti-icing heating control working mode of the unit should be given priority, that is, the first working mode. The unit heating system should be started in time at the beginning of freezing and icing, and the anti-freezing disaster system of the unit should be started only after the wind turbine is shut down due to freezing and icing.

[0062] Control methods such as Figure 6 As shown, the temperature and pressure operating parameters of the high-temperature hot air within the blade heat pipe are independently controlled, prioritizing the heating safety requirements of the blade equipment itself, followed by considerations of improving the unit's anti-freezing performance and energy efficiency. When selecting the heat pipe (high-temperature composite pipe), the inherent high-temperature resistance technical requirements must be taken into account. A single closed-loop negative feedback control method is used to achieve constant temperature control of blade heating. Air is the anti-freezing heat transfer medium for wind turbines. The air velocity and flow rate determine the heat transfer efficiency of the medium and the heat transfer distance to the blade tip. Controlling the air pressure effectively improves the unit's anti-freezing performance and saves heating energy. Figure 6 Where T and T* are the hot air temperature control value and given value respectively, and P and P* are the hot air pressure control value and given value respectively.

[0063] 2. Operation steps:

[0064] Step 1: When the ambient temperature of the wind turbine is lower than 2°C, anti-freezing disaster prediction is performed. If any of the following conditions are met, the wind turbine anti-freezing disaster system is activated:

[0065] a. When the first condition is met, proceed to step 2;

[0066] b. When the second condition is met, proceed to step 3;

[0067] c. When the wind turbine stops operating due to blade freezing and icing, go to step 3;

[0068] Step 2: Start the first working mode. When the wind turbine generator output is close to the normal value or the ambient temperature rises to 0°C or above, proceed to step 4.

[0069] Step 3: Start the second working mode. When the wind turbine generator output is close to the normal value or the ambient temperature rises to 0℃ or above, enter step 4.

[0070] Step 4: The wind turbine blade heating control working mode ends.

[0071] 3. Start / Stop Method

[0072] (1) Startup method: From the monitoring platform in the central control room of the 110kV booster station, set the inverter starting frequency to 20Hz, start the inverter and blower, check that the equipment is operating normally and continuously for 30 seconds, then start the power regulator and duct heater. The initial setting value of the power regulator startup control temperature is 30℃. Then adjust the control value according to the control requirements of the unit de-icing / anti-icing heating control working mode. At this point, the system startup is completed.

[0073] (2) Shutdown method: After determining to stop the wind turbine anti-icing / de-icing heating system, first slowly adjust the temperature setting value of the stepless power regulator back to 30℃ and shut down the stepless power regulator and heater. Then, after an interval of 1 minute, start adjusting the inverter control setting value to 20Hz, stop the inverter and blower, and the wind turbine blade heating system is shut down.

[0074] Example 1

[0075] An anti-freezing system for a 5MW wind turbine with 97m composite blades comprises a heating unit, a detection unit and a control unit.

[0076] In the embodiment, Figure 1 and Figure 2 As shown, the power of the blower 3 is selected to be 5kW, and the power of the duct heater 4 is selected to be 35kW; the heat pipe 5 is selected to be a φ50 high-temperature resistant composite pipe with a maximum temperature resistance of not less than 100°C, and its installation length is 60m from the outlet of the duct heater along the blade tip direction; the wind shield 6 is selected to be a high-strength composite board, and its installation position is in the middle position of the heat pipe 5 (30m); a PT100 temperature sensor is installed on the outer wall of the heat pipe 5 1m away from the outlet of the duct heater 4, and a gas pressure sensor is installed at an interval of 1m, and a patch temperature sensor is installed on the inner wall of the blade at the outlet of the heat pipe 5. All sensor detection signals are connected and laid using coaxial cables with a reserved length of 10m; 60mm diameter circular holes are set on the center line of the blade tip section of the shear web 2 at intervals of 1m, with a total of 5 holes; all equipment installation, cable laying and hole making in this solution are implemented during the blade manufacturing process and are completed in coordination with different blade manufacturing process flows.

[0077] like Figure 3As shown, the 690V power supply is connected from the high-voltage side of the dry-type transformer at the bottom of the wind turbine tower, and the 380V power supply is connected from the cabin control cabinet, and respectively connected to the corresponding power supply terminals of the blade heating power supply control device; the blade heating power supply control device includes a stepless power regulator, a frequency converter, and a PLC device unit to achieve stepless power regulation of the duct heater and variable frequency speed regulation of the blower; the 690V power supply is connected to the power supply terminal of the stepless power regulator, and the 380V power supply is connected to the power supply terminal of the frequency converter; the stepless power regulator and the frequency converter in the blade heating power supply control device The output power supply enters the fan hub through the fan slip ring and the main shaft hole, and is divided into three parts and then connected to the duct heaters and blowers in the three blades respectively, so that one stepless power regulator controls the operation of three duct heaters and one frequency converter controls the operation of three blowers, which simplifies the system structure, reduces the additional load on the equipment unit and the wind turbine hub; when the power cable and signal coaxial cable pass through the blade manhole cover to the hub, a twist cable bracket should be installed to prevent friction, shaking damage or pulling caused by the blade pitch control rotation and the wind turbine rotation.

[0078] Heating control of wind turbine anti-freezing system Figure 4 、 Figure 5 and Figure 6 As shown, the system primarily includes duct heater and blower operation control, heat pipe operating condition detection, and blade tip heating temperature monitoring. Heat pipe operating parameters include heated air temperature and pressure. A PT100 temperature sensor is installed 1 meter from the duct heater outlet heat pipe, followed by a gas pressure sensor at 1 meter intervals. The temperature sensor, along with the stepless power regulator within the duct heater and blade heating power supply control unit, forms an independent single closed-loop negative feedback control system to achieve constant temperature control and regulation of the heat pipe's heated air. This system utilizes a PI control algorithm, with the temperature feedback signal being the maximum value from the three temperature sensors. The gas sensor, along with the frequency converter within the blower and blade heating power supply control unit, forms an independent single closed-loop negative feedback control system to achieve constant pressure control and regulation of the heat pipe's heated air. This system utilizes a PI control algorithm, with the pressure feedback signal being the maximum value from the three pressure sensors. The heat pipe's temperature and pressure control setpoints are remotely set and adjusted on the monitoring platform in the 110kV booster station's central control room.

[0079] In the embodiment, the wind turbine is not equipped with an ice detector. At 15:00 on January 16, 2023, the ambient temperature outside the cabin of a wind turbine in a certain wind farm remains below 2°C for a long time and the ambient humidity is 90%. The wind turbine anti-freezing disaster system triggers the start-up conditions and begins to enter the first working mode, implementing anti-icing work for the wind turbine to prevent the wind turbine from being shut down due to condensation and icing.

[0080] When the ambient temperature rises to 2°C or above and the wind turbine generator set generates normal power, the wind turbine generator set blade heating control working mode ends.

[0081] While the preferred embodiments of the present invention have been described in detail above, it should be understood that, after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention. Such equivalents also fall within the scope of the claims appended hereto.

Claims

1. A 100-meter-class blade wind turbine anti-freezing disaster system, characterized in that: The anti-freezing system of the 100-meter-class blade wind turbine includes a wind turbine blade, a heating unit and an anti-shear web arranged on the wind turbine blade, and the wind turbine blade includes a blade root and a blade tip arranged at both ends of the wind turbine blade. One end of the anti-shear web is arranged close to the blade root and the other end of the anti-shear web extends toward the blade tip. The heating unit includes a blower, an air duct heater and a heat conducting pipe arranged near the anti-shear web. The blower and the air duct heater are arranged near the root, and the heat conducting pipe is arranged along the anti-shear web. The blower, the air duct heater and the heat conducting pipe are fluidically connected. The air blown out from the blower passes through the air duct heater and the heat conducting pipe and then flows out from the air outlet end of the heat conducting pipe. The opening of the air outlet end of the heat conducting pipe faces the blade tip.

2. The anti-freezing system for a 100-meter-class blade wind turbine according to claim 1 is characterized in that: The heat pipe is fixed on the leading edge anti-shear web, and the distance from the air outlet end of the heat pipe to the blade root is 2 / 3 of the total length of the wind turbine blade, and the total length of the wind turbine blade is the distance from the blade root to the blade tip.

3. The anti-freezing system for a 100-meter-class blade wind turbine according to claim 1 is characterized in that: The wind turbine blade also includes a windshield arranged perpendicular to the direction from the blade root to the blade tip. The distance from the windshield to the blade root is 1 / 3 of the total length of the wind turbine blade. The total length of the wind turbine blade is the distance from the blade root to the blade tip.

4. The anti-freezing system for a 100-meter-class blade wind turbine according to claim 1 is characterized in that: The anti-shear web is further provided with 5 to 10 circular holes, which are arranged on the center line of the anti-shear web. Starting from the blade tip, a circular hole with a diameter of 60 to 100 mm is arranged every 1 to 2 m.

5. The anti-freezing system for a 100-meter-class blade wind turbine according to claim 1 is characterized in that: A detection unit is also provided on the wind turbine blade, and the detection unit includes a temperature sensor for controlling the gas temperature of the heating unit and a pressure sensor for the gas flow, wherein A first temperature sensor is provided on the inner wall of the wind turbine blade, and the first temperature sensor is located at the air outlet end of the heat pipe. A second temperature sensor and a pressure sensor are respectively provided on the outer wall of the heat pipe. The distance between the second temperature sensor and the outlet of the air duct heater is 1-2m, and the distance between the pressure sensor and the second temperature sensor is 1-2m.

6. The anti-freezing system for a 100-meter-class blade wind turbine according to claim 1 is characterized in that: The anti-freezing system of the 100-meter-class blade wind turbine also includes a control unit, which includes a blade heating power supply control device and a monitoring signal acquisition device. The blade heating power supply control device includes a power regulator for controlling and adjusting the heating power and a frequency converter for adjusting the wind pressure and air volume. The power regulator is used to control and adjust the heating power of the three duct heaters in the three wind turbine blades, and the frequency converter is used to control and adjust the operating air volume of the three blowers in the three wind turbine blades. The monitoring signal acquisition device is used for temperature detection of the temperature sensors and pressure detection of the pressure sensors on the three wind turbine blades, and is used for centralized monitoring of the temperature and flow of the heated air in the heat pipes of the three wind turbine blades.

7. A method for controlling anti-freezing of a 100-meter-class blade wind turbine, which uses the anti-freezing system of a 100-meter-class blade wind turbine described in any one of claims 1 to 6 to perform anti-freezing disaster operations, characterized in that: The following steps are involved: Step 1: When the ambient temperature of the wind turbine is lower than 2°C, anti-freezing disaster prediction is performed. If any of the following conditions are met, the wind turbine anti-freezing disaster system is activated: a. When the first condition is met, proceed to step 2; b. When the second condition is met, proceed to step 3; c. When the wind turbine stops operating due to blade freezing and icing, go to step 3; Step 2: Start the first working mode. When the wind turbine generator output is close to the normal value or the ambient temperature rises to 0°C or above, proceed to step 4. Step 3: Start the second working mode. When the wind turbine generator output is close to the normal value or the ambient temperature rises to 0℃ or above, enter step 4. Step 4: The wind turbine blade heating control working mode ends.

8. The anti-freezing control method for a 100-meter-class blade wind turbine according to claim 7, characterized in that: Step 1 also includes a startup method, which includes: Set the inverter frequency set value to 20 Hz, start the inverter and blower, check that the blower operates normally and continuously for 30 seconds, then start the power regulator and duct heater. The power regulator starts and controls the temperature to an initial set value of 30° C., and then adjust the control value according to the control requirements of the de-icing heating control working mode or the anti-icing heating control working mode.

9. The anti-freezing control method for a 100-meter-class blade wind turbine according to claim 7, characterized in that: In step 2, the temperature range of the wind turbine blades in the anti-icing heating control working mode is 50° C. to 60° C.; In step 3, the temperature range of the wind turbine blades in the de-icing heating control working mode is 60° C. to 80° C.

10. The anti-freezing control method for a 100-meter-class blade wind turbine according to claim 7, characterized in that: In step 2, the first condition is: if an ice detector is installed, when the ice detector detects that the ice thickness is 0.1 mm or greater, or if an ice detector is not installed, when the ambient temperature is lower than 2°C and the ambient humidity is greater than 85%; In step 3, the second condition is: when the ambient temperature of the wind turbine generator set is lower than -5°C; In step 4, the "end of the wind turbine blade heating control operating mode" includes: slowly adjusting the control temperature setpoint of the power regulator back to 30°C, shutting down the power regulator and heater, and starting to adjust the inverter control setpoint to 20 Hz after 1 minute, shutting down the inverter and blower. At this point, the wind turbine blade heating anti-freezing disaster system is shut down.

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