Active control optimization system and method for wake flow of fan

Abstract

A fan wake flow active control optimization system and method reduce the wake flow air temperature and increase the density by spraying atomized water drops so as to increase the wind speed and improve the inflow condition of a downstream fan. The facility comprises a water source supply device, a high-pressure atomization device and a control unit. The water source supply device is responsible for supplying water to the high-pressure atomization device, the high-pressure atomization device atomizes the water and sprays the water to a wake flow area, water drops are promoted to be gasified and absorb heat, and air cooling and density increasing are achieved. According to the system and the method, the power generation efficiency of the wind power plant is improved, the service life of the fan is prolonged, and the system and the method are suitable for offshore and onshore wind power plants and have remarkable economic benefits.

Description

Technical Field

[0001] The invention relates to wind farm technology, and in particular to a wind turbine wake active control optimization system and method. Background Art

[0002] The wind turbine wake is a low-speed, high-turbulence area formed downstream after the wind turbine is running, and its impact range can reach more than 15 times the diameter of the impeller. The existence of the wake will cause a significant loss of power to the wind turbine behind the wake, and at the same time cause the tower stress fluctuation to surge by 80%, accelerating the fatigue failure of wind turbine blades and other components. When an inversion layer exists, the low wind speed period of the wake may even be extended by 2-3 times, which will lead to a significant reduction in the equivalent full-power hours of the wind farm in this scenario, causing significant economic losses. Therefore, the active control and optimization technology of the wake is of great significance to the development of the wind power industry. It can reduce the power loss of downstream wind turbines while reducing the impact of high turbulence areas on the fatigue load of wind turbine components.

[0003] At present, there are a large number of wake control technology solutions, such as application numbers 2024110678791, 2024105633818, 202310853932X, 2021116713348, 2024105633818, 2024101642625, 2023110095577, 2022112893717, 2022110933086, 2021116713348 and other Chinese invention patents. These solutions basically change the direction of the wake through the yaw angle of the wind turbine, so that the main direction of the wake avoids the next wind turbine as much as possible, thereby reducing power loss. The existing technology has continuously studied many yaw optimization strategies to further improve this solution. However, existing solutions often sacrifice the power generation of the first wind turbine. At the same time, for relatively densely arranged wind farms, even if the impact of the wake on the current array wind turbine is reduced, it may also increase the degree of influence of the wake on the adjacent array wind turbines. Therefore, the optimization effect is usually limited (5%~15%). Therefore, if we want to achieve better control of the wake, we urgently need a breakthrough wake optimization control solution.

[0004] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0005] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a system and method for actively controlling and optimizing the wake of a wind turbine.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A wind turbine wake active control optimization system, comprising: A water supply device, used for supplying water to the high-pressure atomizing device; The high-pressure atomization device is arranged at the hub nacelle of the fan and connected to the water supply device, and is used to atomize water and spray it into the wake area, wherein the sprayed atomized water droplets realize gasification phase change and heat absorption in the wake area, reduce the temperature of the wake air and increase its density, and the wake air generates a downward component velocity, inducing the high-speed air above the wake area to be replenished downward, thereby increasing the wind speed in the wake area and improving the inflow conditions of the downstream fan; A control unit is used to control the operation of the water supply device and the high-pressure atomization device, including controlling the water extraction volume, the spraying parameters of the atomized water droplets, and the operating state of the wake induction, so as to optimize the wind speed distribution in the wake area and improve the inflow wind speed and power generation efficiency of the downstream wind turbine.

[0007] Furthermore, the wind turbine is an offshore wind turbine, and the water supply device includes a seawater extraction device for extracting seawater and conveying it to the high-pressure atomization device.

[0008] Furthermore, the seawater extraction device includes a seawater filtering device, a water supply high-pressure pump and a vacuum pump, which are installed around the wind turbine tower on the sea surface, wherein the seawater filtering device is used to filter seawater, the water supply high-pressure pump is used to transport the filtered seawater to the high-pressure atomization device, and the vacuum pump is used to extract seawater.

[0009] Furthermore, the high-pressure atomization device includes an atomization high-pressure pump and an atomization nozzle assembly, wherein the atomization high-pressure pump is used to pressurize the liquid working medium and deliver it to the atomization nozzle assembly; the atomization nozzle assembly includes a plurality of atomization nozzles, and the plurality of atomization nozzles are evenly distributed in a preset area behind the cabin and are connected to the atomization high-pressure pump through a water supply pipeline.

[0010] Furthermore, the rated flow rate of the atomizing high-pressure pump is not less than 1500 liters / minute @4Mpa, so as to meet the spraying process of atomized water droplets with a particle size of 0.1mm~0.2mm at 0~25kg / s.

[0011] Furthermore, the atomizing nozzles are distributed at least 100m behind the cabin. 2 The circular or rectangular range area is connected to the atomizing high-pressure pump through a water supply pipe, and the flow rate of a single atomizing nozzle is 3~6 liters / minute.

[0012] Furthermore, the atomization spraying range of the high-pressure atomization device in the rear area of ​​the cabin is not less than 100m 2 ; The flow rate of water droplets sprayed per second ranges from 0 to 50 Kg / s; the particle size of water droplets ranges from 0.1 mm to 0.2 mm; the air temperature when spraying water droplets is not lower than 285 K.

[0013] A method for actively controlling and optimizing a fan wake is disclosed, wherein the active control and optimization system for a fan wake is used to perform active control and optimization of a fan wake, wherein atomized water droplets are sprayed into the wake region of the fan, and the density of the wake air increases after the temperature is reduced, thereby generating a downward component velocity in the wake region. After the wake air sinks, the high-speed air above the wake region is induced to enter the wake region to supplement the sinking air, thereby increasing the wind speed in the wake region and improving the inflow conditions of the downstream fan.

[0014] The present invention has the following beneficial effects: The present invention provides a system and method for actively controlling and optimizing the wake of a wind turbine, which realizes the absorption of heat by gasification phase change by spraying atomized water droplets, effectively reduces the temperature of the wake air and increases its density, causes the wake air to sink and induces high-altitude wind speed to enter the wake area, thereby significantly improving the inflow wind speed and power generation efficiency of the rear exhaust fan. Compared with the prior art, the present invention can not only reduce the loss of wake power to the downstream wind turbine, but also reduce the impact of high turbulence areas on the fatigue load of wind turbine components, increase the service life of the wind turbine and reduce maintenance costs. In addition, the technical solution of the present invention is not only limited to offshore wind farms, but also applicable to onshore wind farms, especially those close to sufficient water sources, and has wide applicability and practicality. Through this breakthrough wake optimization control scheme, the present invention can achieve a better wake control effect than the prior art, bringing significant economic benefits to the development of the wind power industry.

[0015] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of the wind turbine wake active control optimization system according to an embodiment of the present invention.

[0017] Figure 2 Schematic diagram of the structure of the wind turbine wake active control optimization system from another angle according to an embodiment of the present invention.

[0018] Figure 3a Schematic diagram of mesh division for numerical simulation of wind turbine wake.

[0019] Figure 3b This is a schematic diagram of the fan arrangement.

[0020] Figure 4 This is a schematic diagram of the wake field generated when the inflow wind speed of 8m / s passes through a 2MW wind turbine array under neutral and stable atmospheric boundary layer conditions. It shows the low-speed and high-turbulence area in the wake area and its impact on the downstream wind turbines.

[0021] Figure 5 Schematic diagram of setting up the heat sink term for the lower half swept area of ​​the fan. The heat sink term is shown in the wake of the fan to simulate the cooling effect of the wake air.

[0022] Figure 6a Schematic diagram of the change in wake wind speed distribution after setting the heat absorption source term.

[0023] Figure 6b Schematic diagram of wake air temperature distribution.

[0024] Figure 6c Schematic diagram of air density distribution in the wake area.

[0025] Figure 6d Schematic diagram of the velocity distribution in the vertical direction (z direction) of the wake area.

[0026] Figure 7 Schematic diagram of the overall seawater spray system according to an embodiment of the present invention.

[0027] Figure 8 Schematic diagram of the temperature, density and velocity distribution of the wake after water droplets are injected using DPM.

[0028] Fig. 9 Schematic diagram of wake turbulence kinetic energy distribution.

[0029] Fig.10 Schematic diagram of the vertical velocity distribution of the wake considering the buoyancy effect and relative humidity of 70%.

[0030] Fig.11 Schematic diagram of the downstream fan power increase considering the buoyancy effect and relative humidity of 70%.

[0031] Fig.12 A schematic diagram of the simulation for the HornsRev wind farm layout.

[0032] Fig.13 The figure is a power situation diagram of a wind farm before and after the wind turbine wake active control optimization system of the present invention is adopted at the first wind turbine in the wind farm. DETAILED DESCRIPTION

[0033] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0035] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] Previous studies have often been limited to the perspective of horizontal adjustment, and have rarely considered breakthroughs from the higher wind speed area above the wake area. Based on an in-depth study of the evolution of large-scale fan wakes and the liquid phase change process in microscopic heat transfer, the inventors proposed a practical way to guide the upper high wind speed to the wake area, thereby increasing the inflow wind speed of the rear exhaust fan and reducing the impact of the wake.

[0038] See also Figure 1 , Figure 2 and Figure 7 The embodiment of the present invention provides a system for actively controlling and optimizing a wind turbine wake, comprising: a water supply device 2, which supplies water to a high-pressure atomizing device 3 through a pumping device (not shown) and a water supply pipeline; a high-pressure atomizing device 3, which is arranged at a position of a nacelle 1 of a fan hub and is connected to the water supply device 2, and is used to atomize water and spray it into a wake region, wherein the sprayed atomized water droplets realize gasification phase change heat absorption in the wake region, reduce the temperature of the wake air and increase its density, and the wake air generates a downward component velocity, inducing the high-speed air above the wake region to be replenished downward, thereby increasing the wind speed in the wake region and improving the inflow condition of the downstream fan; a control unit (not shown), which is used to control the operation of the water supply device 2 and the high-pressure atomizing device 3, and the control of the control unit may specifically include controlling the amount of water extracted, the spraying parameters of the atomized water droplets, and the running state of the wake induction, so as to optimize the wind speed distribution in the wake region and improve the inflow wind speed and power generation efficiency of the downstream fan.

[0039] In a preferred embodiment, the wind turbine is an offshore wind turbine, and the water supply device 2 includes a seawater extraction device for extracting seawater and transporting it to the high-pressure atomization device 3 .

[0040] In a preferred embodiment, the seawater extraction device includes a seawater filtering device, a water supply high-pressure pump and a vacuum pump, which are installed around the wind turbine tower on the sea surface, wherein the seawater filtering device is used to filter seawater, the water supply high-pressure pump is used to transport the filtered seawater to the high-pressure atomization device 3, and the vacuum pump is used to extract seawater.

[0041] See also Figure 1 In a preferred embodiment, the high-pressure atomization device 3 includes an atomization high-pressure pump (not shown) and an atomization nozzle assembly, wherein the atomization high-pressure pump is used to pressurize and deliver the liquid working medium to the atomization nozzle assembly; the atomization nozzle assembly includes a plurality of atomization nozzles, such as Figure 1 As shown, the multiple atomizing nozzles are evenly distributed in a preset area behind the cabin 1 and are connected to the atomizing high-pressure pump through a water supply pipeline. The nozzle spacing meets the discrete requirements of the atomized droplets to form a uniform atomization coverage in the wake area. The control unit adjusts the atomization parameters, can dynamically adjust the atomized particle size to a preset range, and control the outflow rate of a single nozzle.

[0042] In a preferred embodiment, the rated flow rate of the atomizing high-pressure pump is not less than 1500 liters / minute @ 4 MPa, so as to meet the spraying process of atomized water droplets with a particle size of 0.1 mm to 0.2 mm at a rate of 0 to 25 kg / s.

[0043] In a preferred embodiment, the atomizing nozzles are distributed at least 100m behind the cabin 1. 2 The circular or rectangular range area is connected to the atomizing high-pressure pump through a water supply pipe, and the flow rate of a single atomizing nozzle is 3~6 liters / minute.

[0044] In a preferred embodiment, the atomization spraying range of the high-pressure atomization device 3 in the rear area of ​​the cabin 1 is not less than 100m. 2 ; The flow rate of water droplets sprayed per second ranges from 0 to 50 Kg / s; the particle size of water droplets ranges from 0.1 mm to 0.2 mm; the air temperature when spraying water droplets is not lower than 285 K.

[0045] An embodiment of the present invention also provides a method for actively controlling and optimizing a fan wake, which uses the active control and optimization system for a fan wake of any of the aforementioned embodiments to perform active control and optimization of a fan wake, wherein atomized water droplets are sprayed into the wake region of the fan, and the density of the wake air increases after cooling, thereby generating a downward component velocity in the wake region. After the wake air sinks, the high-speed air above the wake region is induced to enter the wake region to replenish the sinking air, thereby increasing the wind speed in the wake region and improving the inflow conditions of the downstream fan.

[0046] The specific embodiments of the present invention and the effect verification are further described below.

[0047] A wind turbine wake active control optimization system provides a solution for spraying atomized water droplets to absorb heat through vaporization phase change to cool the air, causing the wake air with high density relative to the environment to sink. The system includes a water supply device 2, a high-pressure atomization device 3, and a control unit. For offshore wind turbines, the water supply device 2 extracts seawater from the seawater to the nacelle 1 position of the wind turbine hub, and the seawater is sprayed through the high-pressure atomization device 3 installed at the nacelle 1 position. With the help of temperature difference and high wind speed, the water droplet vaporization process is accelerated, so that the wake air is cooled and sinks, and finally the high-altitude wind speed is induced to enter the wake area.

[0048] The water supply device 2 of one embodiment mainly includes a seawater filter, a water supply high-pressure pump and a vacuum pump, which are installed around the tower on the sea surface, and the rated flow rate is not less than 3000 liters / minute @2Mpa at a suction depth of 3 meters. Since seawater is extracted, the material is required to be resistant to seawater corrosion. The vertical water supply height of the water supply high-pressure pump can reach 100m. The vacuum pump can adopt a mechanical fully automatic piston vacuum pump.

[0049] The high-pressure atomization device 3 includes an atomization high-pressure pump and an atomization nozzle, which are installed at the position of the cabin 1. The system can be installed outside the cabin 1 on the premise of meeting the tower load-bearing capacity. The rated flow rate of the atomization high-pressure pump is not less than 1500 liters / minute @4Mpa to meet the spraying process of 0~25kg / s atomized water droplets with a particle size of 0.1mm~0.2mm. The atomization nozzles are distributed in a circular or rectangular range area behind the cabin 1 and connected by a water supply pipe. The atomization nozzle can adopt the Lechler 502.448 model nozzle, which can provide atomized water droplets with a particle size of about 0.1~0.2mm according to different operating pressures of 1Mpa~4Mpa. The flow rate of a single nozzle is 3~6 liters / minute, and there are 250 nozzles in total. In order to ensure the evaporation effect of the water droplets after atomization and reduce the agglomeration effect between the atomized water droplets, a certain distance must be guaranteed between each nozzle, so the nozzles are evenly distributed at least 100m behind the cabin 1. 2 The maximum power of the high-pressure atomization device 3 is the maximum pressure multiplied by the maximum flow rate, that is, the power of atomization water spraying at 25kg / s under 4Mpa is 100KW. In fact, the purpose of reducing power consumption can be achieved by increasing the number of nozzles and reducing the atomization particle size.

[0050] The control unit controls the operation of the water supply device 2 and the high-pressure atomization device 3, including the extraction amount of seawater (onshore fresh water), the spraying parameters of the atomized water droplets, and the operating state of the wake induction device. It can be adjusted in real time according to the severity of the wake impact on the actual wind farm, similar to the wake optimization control system using the yaw scheme, and a similar algorithm can also be designed.

[0051] The wake of the fan was numerically simulated based on FLUENT software. The grid division and fan arrangement are shown in the figure. Figure 3a and Figure 3b shown. Figure 3a The schematic diagram of meshing for numerical simulation of wind turbine wake is shown. Different boundary conditions are marked in the figure, including pressure outlet a1, zero shear upper boundary a2, velocity inlet a3, no-slip bottom boundary a4 and periodic boundary a5. The mesh sizes are 250m, 500m and 2000m respectively, which are used to simulate different areas of the wind farm. Figure 3b The diagram shows the layout of wind turbines. The figure shows the inflow wind speed b1, the wake area b2, the upper blade tip height b3, the hub height b4 and the lower blade tip height b5. The coordinate axes (x / d and z / d) show the distribution of the wind turbine wake area, where x / d represents the horizontal distance and z / d represents the vertical height. Under the conditions of a neutral stable atmospheric boundary layer, an inflow wind speed of 8m / s will produce the following when passing through a 2MW wind turbine array. Figure 4 Assume that a fixed heat sink is provided at the wind turbine location, for example, in the lower half of the wind turbine swept area. Figure 5 After setting the heat source term, the wind field passing through this area will absorb heat and produce a cooling effect. When the calculation reaches stability, the inventor found that the wind speed distribution of the wake has changed significantly, as shown in Figure 6a As shown in the figure, the inventors found that the low wind speed distribution of the wake is no longer distributed straightly along the downstream direction, but actually shows a certain degree of drooping trend. At the same time, compared with the result without adding the heat source term, the wind speed at the inflow position of the second fan under the wake has increased significantly. The fundamental reason for this phenomenon is that the wake air temperature is reduced ( Figure 6b ), which in turn increases the density of the local air ( Figure 6c ), because its density is lower than that of the lower air layer, a downward component velocity is generated in the wake area, such as Figure 6d As shown in the figure, the maximum speed in the z direction reaches -1m / s, which induces the air above the wake to replenish downward, and finally accelerates the recovery process of the wake wind speed. Comparing the power of the second and third wind turbines before and after cooling, it is found that the power of the second wind turbine increased by about 30% after cooling, and the power of the third wind turbine increased by about 40%. This is an unprecedented improvement for the optimization control of the wake.

[0052] By integrating the heat source term in the cooling area behind the first fan, it is found that Figure 6b The cooling effect of the wake air shown above requires a total of 5×10 7 Joule heat, which is a very large amount of heat. Even if the power of the second fan is increased by 30%, the specific value of the increased power is only 1.4×10 6 W, this value should be significantly smaller than 5×10 7The problem at this time is how to use energy lower than the power gain of the fan to achieve the effect of lowering the required temperature. The ideal approach is to use the existing heat. The inventor thought of using the latent heat of water phase change.

[0053] The atomized water droplets will evaporate and gasify quickly in the high-speed flowing high-temperature air. This phase change process is enough to take away a lot of heat energy. 7 Joules of heat are only needed to evaporate 25kg of water per second in the air. To lift 25kg of water to a height of 70m (the height of the wind turbine hub), the gravitational potential energy that needs to be overcome per second is only 17500W, which is 1 / 9 of the wake optimization power gain. The rest of the work is to accelerate the vaporization process of water.

[0054] The lifted seawater is sprayed into the relatively high temperature unsaturated atmosphere (humidity) by a high-pressure atomization device (forming small droplets to increase the contact area between water and liquid), thereby causing the seawater to vaporize in the high-altitude wake area to achieve a phase change endothermic process. Generally speaking, the smaller the particle size, the higher the air temperature, the lower the air humidity and the greater the wind speed, the more conducive to the vaporization process of the water droplets. Therefore, the present invention essentially uses the phase change latent heat of seawater in a circuitous and clever way to improve the power generation efficiency of the wake fan. For offshore wind turbines, the feasibility of this solution is very high because seawater is easy to obtain; for onshore wind turbines, in order to realize this solution, a wind farm close to a water source is considered. The overall schematic diagram is as follows Figure 7 shown. Figure 7 At the same time, the working principle of the seawater spray system was demonstrated. By spraying atomized water droplets, the temperature of the tail air was reduced and its density was increased, thereby increasing the wind speed and improving the inflow conditions of the downstream wind turbines. Figure 7 In the figure, b1 represents the inflow wind speed entering the fan area, b2 represents the wake area, b6 represents the water source extracted from the seawater and supplied to the high-pressure atomization device, and b7 represents the high-pressure atomization device spraying water droplets to atomize the seawater and spray it into the wake area. b8 represents the water droplets vaporizing and lowering the temperature to form air sinking. Since the sprayed water droplets vaporize and absorb heat in the wake area, the air temperature drops and the density increases, causing the air to sink. b9 represents the process of accelerating the upper wind speed to enter the wake area. After spraying water droplets to vaporize and cool down, the upper high wind speed air is induced to enter the wake area.

[0055] In a preferred embodiment, the atomization spraying range in the rear area of ​​the cabin is not less than 100m 2The water droplet flow rate per second can be adjusted according to actual needs, and the flow rate range is 0~25Kg / s. If the wind farm is more seriously affected by the wake, the flow rate range can be increased to 0~50Kg / s; the particle size range of the water droplets is between 0.1mm and 0.2mm. Using too large a particle size will excessively reduce the evaporation efficiency, and using too small a particle size will excessively increase the atomization cost. After calculation, the particle size range of 0.1mm~0.2mm is the best choice; preferably, the air temperature when spraying water droplets is not lower than 285K, otherwise the gasification effect will be greatly reduced. The above are all range references obtained by simulation experiments.

[0056] During the test, the inventor added a simulation of the gasification phase change process of water droplets in the air to the original wind field simulation, using the DPM module in FLUENT. 25 kg of water droplets were injected per second into a 40 m × 40 m rectangular area behind the wind turbine cabin. The droplet size was 0.0001 m (0.1 mm), the temperature of the droplets was 295 K (5 K lower than the air temperature), the ejection velocity was 5 m / s, and the inflow air was dry air. Use the DPM (discrete phase model) in the FLUENT software to set the discrete phase (such as water droplets) to set the injection parameters.

[0057] After calculation, it is found that the effect of reducing the wake and increasing the air density by injecting water droplets using DPM is almost the same as the effect of only introducing the heat source term before. Figure 8 As shown, this confirms the inventor's previous conjecture. And by only arranging a seawater spray device in the wake area of ​​the Ruliu fan, the influence of the wake on the fan power at the second and third wakes can be reduced at the same time.

[0058] In addition, this solution can also greatly reduce the turbulent kinetic energy in the wake, thereby reducing the fatigue load on the rear exhaust fan blades. Fig. 9 As shown, this effect can increase the service life of the fan to a certain extent and reduce maintenance costs.

[0059] In the scenario studied in the present invention, the sea water temperature is lower than the atmosphere, and the density of the lower air layer close to the sea surface will be greater than the density of the upper air layer, which belongs to the stable atmospheric condition (SBL). Therefore, it is also necessary to consider the inhibitory effect of the buoyancy effect on the wake recovery. At this time, the influence of the wake effect will be greater than the neutral stable condition. At the same time, it is also necessary to consider that the sea air is in a state of high relative humidity, which will be unfavorable to the vaporization process of water droplets to a certain extent. Therefore, the present invention carried out a numerical simulation that is more in line with the actual situation of offshore wind farms. The buoyancy effect was taken into account during the simulation, and the original dry air was set to a relative humidity of 70%. Compared with the ideal situation, the buoyancy effect limits the sinking of the wake air to a certain extent. Fig.10 As shown, its vertical speed is less than Figure 8Even so, the proposed wake control method can still bring considerable power improvement to the downstream wind turbine, such as Fig.11 shown.

[0060] Since the Reynolds time-averaged (RANS) method will overestimate the wake recovery process, the large eddy simulation (LES) technology is used for further research. In the large eddy simulation, the actual existing HornsRev wind farm layout is simulated. The simulation area is as follows Fig.12 As shown, a total of 8 2MW wind turbines were simulated at a wind direction of 270°.

[0061] When the wind speed is 8m / s and the air temperature is 300K, the wind farm power before and after the wake optimization control device proposed by the present invention is used at the first wind turbine is as follows: Fig.13 As shown, it can be found that in the results obtained by large eddy simulation, the wake optimization effect of the present invention is more significant. The wake optimization effect of the present invention is sufficient to increase the power of the second wind turbine by 0.17MW when the wake optimization effect of the present invention is used only in the first wind turbine, and the increase is close to 60% of the original power. It also has a certain improvement effect on the subsequent wind turbines. Finally, the total power increase of the wind turbine array exceeds 0.2MW, and this power increase far exceeds the power consumption generated by the wake optimization equipment.

[0062] The present invention is applicable not only to offshore wind farms, but also to onshore wind farms with sufficient water sources. After multiple working condition calculations, the scope of applicable scenarios is obtained. When the wind speed at the hub height is not less than 4m / s, the temperature is not less than 285K (12°C), and the relative humidity of the air is not greater than 80%, the effect can be fully exerted. The above scenarios occupy more than half of the time in most areas throughout the year, which shows that the present invention is not only feasible in specific scenarios, but also has a wider range of application scenarios.

[0063] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A wind turbine wake active control optimization system, characterized in that: include: A water supply device, used for supplying water to the high-pressure atomizing device; The high-pressure atomization device is arranged at the hub nacelle of the fan and is connected to the water supply device, and is used to atomize water and spray it into the wake area, wherein the sprayed atomized water droplets realize gasification phase change and heat absorption in the wake area, reduce the temperature of the wake air and increase its density, and the wake air generates a downward component velocity, inducing the high-speed air above the wake area to replenish downward, thereby increasing the wind speed in the wake area and improving the inflow conditions of the downstream fan; A control unit is used to control the operation of the water supply device and the high-pressure atomization device, including controlling the water extraction volume, the spraying parameters of the atomized water droplets, and the operating state of the wake induction, so as to optimize the wind speed distribution in the wake area and improve the inflow wind speed and power generation efficiency of the downstream wind turbine.

2. The wind turbine wake active control optimization system according to claim 1, characterized in that: The wind turbine is an offshore wind turbine, and the water source supply device includes a seawater extraction device for extracting seawater and conveying it to the high-pressure atomization device.

3. The wind turbine wake active control optimization system according to claim 2, characterized in that: The seawater extraction device includes a seawater filtering device, a water supply high-pressure pump and a vacuum pump, and is installed around the wind turbine tower on the sea surface, wherein the seawater filtering device is used to filter seawater, the water supply high-pressure pump is used to transport the filtered seawater to the high-pressure atomization device, and the vacuum pump is used to extract seawater.

4. The wind turbine wake active control optimization system according to claim 1, characterized in that: The high-pressure atomization device includes an atomization high-pressure pump and an atomization nozzle assembly, wherein the atomization high-pressure pump is used to pressurize and deliver the liquid working medium to the atomization nozzle assembly; the atomization nozzle assembly includes a plurality of atomization nozzles, and the plurality of atomization nozzles are evenly distributed in a preset area behind the cabin and are connected to the atomization high-pressure pump through a water supply pipeline.

5. The wind turbine wake active control optimization system according to claim 4, characterized in that: The rated flow rate of the atomizing high-pressure pump is not less than 1500 liters / minute @4Mpa, so as to meet the spraying process of atomized water droplets with a particle size of 0.1mm~0.2mm at 0~25kg / s.

6. The wind turbine wake active control optimization system according to claim 4, characterized in that: The atomizing nozzles are distributed at least 100m behind the cabin 2 The circular or rectangular range area is connected to the atomizing high-pressure pump through a water supply pipe, and the flow rate of a single atomizing nozzle is 3~6 liters / minute.

7. The wind turbine wake active control optimization system according to claim 1, characterized in that: The spraying range of the high-pressure atomizing device in the rear area of ​​the cabin is not less than 100m 2 The flow rate of water droplets sprayed per second ranges from 0 to 50 Kg / s; the particle size of water droplets ranges from 0.1 mm to 0.2 mm; the air temperature when spraying water droplets is not lower than 285 K.

8. A method for optimizing active wind turbine wake control, characterized in that: Active fan wake control optimization is performed using the fan wake active control optimization system according to any one of claims 1 to 7, wherein atomized water droplets are sprayed into the wake area of ​​the fan, the density of the wake air increases after cooling, and a downward component velocity is generated in the wake area. After the wake air sinks, the high-speed air above the wake area is induced to enter the wake area to supplement the sinking air, thereby increasing the wind speed in the wake area and improving the inflow conditions of the downstream fan.

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