Search

CN-121993341-A - Down-wind type small wind driven generator turbine

CN121993341ACN 121993341 ACN121993341 ACN 121993341ACN-121993341-A

Abstract

The invention discloses a downwind type small wind driven generator turbine which comprises a rotor blade main body axially sweepback from a blade root to a blade tip, wherein the front edge of the blade is provided with a bionic nodular structure which varies in a sine way, the rear edge of the blade is provided with a zigzag ripple structure, the blade is connected with a hub to form a wind turbine rotor, the rotor is positioned on the downwind side of a tower, wind flows firstly pass through the tower and then act on the rotor blade, the downwind layout enables the blade to naturally feather under the action of wind load, so that the dynamic load impact on the tower is reduced, the yaw system structure is simplified, the integral sweepback blade can obviously relieve the effect of the tower, the pneumatic noise is reduced, the front edge of the blade is simulated on a fin limb of a whale, the lift-drag ratio can be effectively improved, the broadband noise is reduced, the sharp fluctuation of power and load is inhibited, the zigzag ripple of the rear edge of the blade is simulated on the comb structure of the rear edge of the Fei-like, the vortex shedding frequency is inhibited, and the high-frequency noise is obviously reduced.

Inventors

  • CUI TAO
  • WANG DEMING

Assignees

  • 崔涛

Dates

Publication Date
20260508
Application Date
20260403

Claims (10)

  1. 1. A downwind type small wind driven generator turbine, characterized by comprising the following steps: A hub; and at least two blades mounted on the hub; The turbine is configured to be mounted on a leeward side of a tower such that wind flow passes through the tower prior to contacting the blades; the blade is in an integral axial continuous sweepback configuration from the blade root to the blade tip; the front edge of the blade is provided with a bionic nodule structure with sine regular change; The trailing edge of the blade is provided with a saw tooth corrugated structure.
  2. 2. The turbine for a downwind wind turbine of claim 1, wherein the overall axially continuous swept-back configuration is characterized by a smooth curve along the spanwise direction of the blade, the aerodynamic center line of each section of the blade, and the projection of the curve on the plane of rotation is a continuous arc in a single direction, without a point of reverse curvature.
  3. 3. The turbine for a downwind wind turbine of claim 2, wherein the sweep angle of the overall axially continuous sweep configuration increases monotonically along the blade span and the difference between the sweep angle at the blade tip and the sweep angle at the blade root is 15 ° to 35 °.
  4. 4. The turbine for a downwind wind turbine of claim 1, wherein the biomimetic nodule structure is disposed in an inboard region of the spanwise direction of the blade from a first start spanwise location to a first end spanwise location, the first start spanwise location corresponding to a relative radius R/R of from 0.2 to 0.3, the first end spanwise location corresponding to a relative radius R/R of from 0.65 to 0.85, wherein R is a distance from the axis of rotation to the tip of the blade, the biomimetic nodule structure is distributed in a sinusoidal waveform along the spanwise direction of the leading edge of the blade with a ratio of amplitude a to blade local chord length c of from 0.025 to 0.1, and a ratio of wavelength λ to amplitude a of from 3 to 8.
  5. 5. The turbine for a downwind wind turbine of claim 1, wherein the saw tooth corrugation is disposed in an outer region of the blade span from a second start span location to a tip end, the second start span location corresponding to a relative radius R/R of 0.65 to 0.85, wherein R is a distance from the rotational axis to the tip end, wherein a saw tooth apex angle of the saw tooth corrugation is not greater than 90 °, a ratio of a saw tooth height H to a local chord length c of the blade is 0.02 to 0.05, and a spacing between adjacent saw teeth is 1.2 to 2 times the saw tooth height.
  6. 6. The turbine for a downwind wind turbine of claim 4 or 5, wherein the first ending deployment position is less than or equal to the second starting deployment position and a ratio of a maximum amplitude Amax of the biomimetic nodular structure to a maximum height Hmax of the sawtooth ripple structure is 1.2 to 3.5.
  7. 7. A turbine for a downwind wind turbine according to claim 1, wherein a deflection mechanism is provided between the hub and the tower such that a predetermined deflection distance is maintained between the rotation plane of the turbine and the tower centre line to ensure that the minimum clearance between the blades and the tower outer wall during operation is not less than 1.5 times the blade chord length.
  8. 8. The turbine for a downwind wind turbine of claim 1, wherein the blade has a tip speed ratio of 6 to 8 when operated at rated wind speed, and wherein the trailing edge sawtooth ripple reduces blade aerodynamic noise by at least 5dB (a) over this tip speed ratio range.
  9. 9. A wind power generator comprising a tower, a nacelle disposed atop the tower, and a turbine according to any one of claims 1 to 8, the turbine being mounted on the nacelle on a downwind side of the tower.
  10. 10. A blade for a downwind wind turbine, characterized in that the blade has the structural features of the blade according to any one of claims 1 to 8.

Description

Down-wind type small wind driven generator turbine Technical Field The invention relates to the technical field of wind power generation, in particular to a turbine for a downwind wind power generator, a wind power generator comprising the turbine and blades for the turbine. Background The wind driven generator is a device for converting wind energy into electric energy, and the core component of the wind driven generator is a wind wheel (comprising a hub and blades). According to the relative positions of the wind wheel and the tower, the wind driven generator can be divided into an upwind direction layout (the wind wheel is positioned on the tower and wind flows through the tower after passing through the wind wheel) and a downwind direction layout (the wind wheel is positioned on the downwind of the tower and wind flows through the wind wheel after passing through the tower). Upwind layout is the mainstream technical scheme at present, but has the following problems that a complex yaw system is required to be equipped for keeping the wind wheel always facing the wind, and the fatigue life of a tower and the root of a blade is adversely affected due to the fact that the blade bears larger periodic load during operation. In contrast, downwind layout has self-aligning properties, simplifying and even eliminating yaw systems, while blades naturally feathering under wind load, theoretically reducing structural loads. However, the downwind layout has a key problem in practical application, namely, because the wind wheel is positioned in a tower wake area, the blades are periodically influenced by tower shadow effect in the rotating process, so that pneumatic load fluctuation is aggravated, the power generation efficiency is influenced, vibration and noise problems are also caused, and the urban residential areas, roofs and the like are often faced with destiny after being installed. Therefore, how to adapt to the non-uniform inflow working condition of the downwind direction through the pneumatic design of the blade is a technical problem to be solved in the technical direction. In addition, various blade aerodynamic improvements have emerged in the art. For example, patent CN200510088166.4 discloses a blade with a sweep angle, which provides a forward sweep angle on the inner side of the blade and a backward sweep angle on the outer side to achieve load balancing. Although the aerodynamic performance of the blade is improved to a certain extent, the glancing angle distribution of the blade is complex, and the blade is not specially optimized for downwind working conditions. As another example, there are prior art solutions in which biomimetic nodules (leading edge protrusions) or trailing edge serrations are applied to the blades to improve aerodynamic performance or reduce noise, but these solutions are typically applied only individually, without considering the synergy between the features, nor without technical teaching that they are combined with downwind layout and overall swept blades. Disclosure of Invention The invention aims to provide a turbine, a wind driven generator and blades for a downwind wind driven generator, so as to solve the problems of large load fluctuation, low aerodynamic efficiency and high noise level caused by the influence of tower shadow effect on the downwind wind driven generator in the prior art, and realize comprehensive optimization of aerodynamic performance, structural load and noise control. Technical proposal The turbine for the downwind wind driven generator comprises a hub, at least two blades mounted on the hub, the turbine is configured to be mounted on the downwind side of a tower, wind flows through the tower before contacting the blades, the blades are in an integral axial continuous sweepback configuration from a blade root to a blade tip, the front edges of the blades are provided with bionic nodular structures which change in a sine rule, and the rear edges of the blades are provided with sawtooth ripple structures. Further, the integral axial continuous sweepback configuration is characterized in that the pneumatic central connecting line of each section of the blade is a smooth curve along the expanding direction of the blade, and the projection of the curve on a rotation plane is a continuous arc line in a single direction without reverse bending points. Preferably, the sweep angle of the overall axially continuous sweep configuration increases monotonically along the blade span, and the difference between the sweep angle at the blade tip and the sweep angle at the blade root is 15 ° to 35 °. Further, the bionic nodule structure is disposed in an inner region of the blade span from a first starting span position to a first ending span position, the relative radius R/R corresponding to the first starting span position is 0.2 to 0.3, and the relative radius R/R corresponding to the first ending span position is 0.65 to 0.85, wherein R is the distance from the