Power device for vertical axis wind turbine

Abstract

The utility model provides a power device for a vertical axis wind driven generator, which comprises blades and a wind wheel, the wind wheel comprises a wheel shaft and wheel hubs, the upper part of the wheel shaft is coaxially and fixedly connected with one or more wheel hubs, the peripheral sides of the wheel hubs are connected with a plurality of blades through connecting pieces in an annular array, and the bottom end of the wheel shaft is connected with a generator through a speed reducer. The whole blade is strip-shaped, the section of the blade is J-shaped, the opening direction of the blade is deviated from the wheel shaft, the blade comprises a suction surface and a pressure surface, the side, with the small section size, of the blade is the suction surface, the side, with the large section size, of the blade is the pressure surface, the pressure surface is fixedly connected with the connecting piece, and the section length of the suction surface is 25%-35% of the chord length. And the thickness of the pressure surface is 1-2% of the chord length. The wind power generation device is simple and reasonable in structural design, low in manufacturing cost, capable of keeping a good lift-drag ratio under various wind direction conditions, good in aerodynamic performance, high in power generation efficiency, high in economic benefit and capable of being used and popularized.

Description

Technical Field

[0001] The utility model belongs to the technical field of wind power generation, and in particular relates to a power device for a vertical axis wind turbine. Background Art

[0002] Wind power generation, as a clean and renewable energy source, is gradually becoming an important part of the global energy structure, especially in some areas with rich wind energy resources.

[0003] The main operating principle of a wind turbine is to use wind power to drive the blades to rotate, which is then increased through a transmission to drive a generator to generate electricity. Depending on the placement of the rotor, wind turbines are mainly divided into two types: horizontal-axis wind turbines and vertical-axis wind turbines. Horizontal-axis wind turbines are the most common type, with blades rotating around a horizontal axis, which allows for higher efficiency. However, this type of wind turbine must face the wind direction and therefore requires a wind direction adjustment device. Vertical-axis wind turbines, on the other hand, have blades rotating around a vertical axis, allowing them to receive wind from any direction without requiring adjustment. Because vertical-axis wind turbines are more adaptable to wind direction, require a smaller footprint, are relatively easy to operate and maintain, and produce less noise, they are preferred for wind power generation projects in urban areas and residential areas.

[0004] Taking into account factors such as noise, wind speed, and blade strength, improving the aerodynamic performance of vertical axis wind turbines at low tip speed ratios is of great significance for wind power generation in cities and living areas.

[0005] Currently, technologies to improve the aerodynamic performance of vertical-axis wind turbines at low tip speed ratios primarily include the creation of nozzle-type slits, the placement of micro-cylinders in front of the leading edge of the airfoil, and trailing-edge jet flaps. These control methods require complex modifications to the blades, blade support rods, and other components, such as the use of double-elliptical slits, the addition of compressors and air storage chambers within the blades, and the addition of air pumps inside and outside the blades. These modifications are complex and costly, while also increasing the size of the vertical-axis wind turbine. Consequently, there is a need to design a wind turbine blade and associated power unit with a simpler and more rational structure that offers improved aerodynamic performance at low tip speed ratios. Utility Model Content

[0006] The technical problem to be solved by the present invention is to provide a power device for a vertical axis wind turbine in view of the above-mentioned deficiencies in the prior art. The device has a simple and reasonable structural design, low manufacturing cost, can maintain a good lift-to-drag ratio under various wind direction conditions, has good aerodynamic performance, high power generation efficiency, high economic benefits, and can be promoted for use.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a power device for a vertical axis wind turbine, characterized in that it includes blades and a wind wheel, the wind wheel includes a wheel shaft and a hub, the upper part of the wheel shaft is coaxially fixedly connected with one or more wheel hubs, the outer peripheral side of the wheel hub is connected to multiple blades through a ring array of connecting parts, the bottom end of the wheel shaft is connected to the generator through a reducer, the blade is strip-shaped as a whole, the cross-section of the blade is J-shaped, the opening direction of the blade is away from the wheel shaft, the blade includes a suction surface and a pressure surface, the side of the blade with a smaller cross-sectional dimension is the suction surface, and the side of the blade with a larger cross-sectional dimension is the pressure surface, the pressure surface is fixedly connected to the connecting part, the cross-sectional length of the suction surface is 25% to 35% of the radial cross-sectional chord length of the blade, and the thickness of the pressure surface is 1% to 2% of the chord length.

[0008] Preferably, the cross-sectional length of the suction surface is 30% of the chord length, and the thickness of the pressure surface is 1.12% of the chord length.

[0009] Preferably, the input end of the reducer is connected to the wheel axle, and the output end of the reducer is connected to the generator.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] The blade cross-section of the utility model is J-shaped, which can help reduce flow separation and enable the blade to maintain a good lift-to-drag ratio under various wind direction conditions even at a low tip speed ratio. It has excellent power performance, low production cost, high power generation efficiency and good economic benefits.

[0012] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall axonometric three-dimensional structure of the utility model.

[0014] Figure 2 It is a schematic diagram of the three-dimensional structure of the blade in the utility model.

[0015] Figure 3 It is a schematic diagram of the cross-sectional structure of the blade in the utility model.

[0016] Figure 4 It is a schematic diagram of the top structure of the utility model.

[0017] Figure 5 This is a schematic diagram comparing the tip speed ratio-power coefficient of the utility model and a conventional wind turbine.

[0018] Figure 6 This is a schematic diagram comparing the instantaneous power coefficients of the utility model and conventional wind turbines.

[0019] Description of reference numerals:

[0020] 1—blade; 2—hub; 3—connector;

[0021] 4—axle; 5—suction side; 6—pressure side; DETAILED DESCRIPTION

[0022] like Figures 1 to 4 As shown, the utility model includes a blade 1 and a wind wheel. The wind wheel includes a wheel shaft 4 and a wheel hub 2. The upper part of the wheel shaft 4 is coaxially fixedly connected to two wheel hubs 2. The outer peripheral side of the wheel hub 2 is connected to three blades 1 in an annular array via a connector 3. The bottom end of the wheel shaft 4 is connected to the generator via a reducer. The blade 1 is generally strip-shaped, with a J-shaped cross-section. The opening direction of the blade 1 is away from the wheel shaft 4. The blade 1 includes a suction surface 5 and a pressure surface 6. The side of the blade 1 with a smaller cross-sectional dimension is the suction surface 5, and the side of the blade 1 with a larger cross-sectional dimension is the pressure surface 6. The pressure surface 6 is fixedly connected to the connector 3. The blade 1 is made of one piece, and the inner opening of the blade 1 is arc-shaped.

[0023] In this embodiment, the cross-sectional length of the suction surface 5 is 30% of the chord length, and the thickness of the pressure surface 6 is 1.12% of the chord length.

[0024] In this embodiment, the upper and lower outer portions of the pressure surface 6 of the blade 1 are fixedly connected to the upper and lower hubs 2 respectively through two connecting members 3 .

[0025] In this embodiment, the input end of the reducer is connected to the wheel shaft 4 through a coupling, and the output end of the reducer is connected to the motor shaft of the generator through a coupling.

[0026] In this embodiment, the blade 1 is modified from a conventional NACA 2421 blade. In order to demonstrate the performance of this embodiment, the two are compared.

[0027] Chord length (mm) 85.8 Suction surface length (mm) 25.74 (30% chord length) Rotor diameter (mm) 1030 Number of blades 3 Thin layer thickness (mm) 1 (1.12% chord length) Tip speed ratio 1.44-3.3

[0028] Table 1

[0029] Table 1 shows the parameters of blade 1 in this embodiment, and the comparison results with the unmodified NACA2421 blade are as follows: Figure 5 As shown in FIG. 1 , when the tip speed ratio TSR of the blade 1 of this embodiment is 1.44, the power coefficient Cp increases by 54.49%; when the tip speed ratio TSR is 1.68, the power coefficient Cp increases by 71.23%; when the tip speed ratio TSR is 2.04, the power coefficient Cp is close to the value of the blade 1 of FIG. Figure 6 As shown, the instantaneous power coefficient of the wind turbine of this embodiment is improved in most operating phase angles compared with the vertical axis wind turbine of the prior art.

[0030] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation of the above embodiment made according to the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A power device for a vertical axis wind turbine, characterized in that: The invention comprises a blade (1) and a wind wheel, wherein the wind wheel comprises a wheel shaft (4) and a wheel hub (2), the upper part of the wheel shaft (4) is coaxially fixedly connected to one or more wheel hubs (2), the outer peripheral side of the wheel hub (2) is connected to a plurality of blades (1) in an annular array via a connecting piece (3), the bottom end of the wheel shaft (4) is connected to a generator via a reducer, the blade (1) is strip-shaped as a whole, the cross section of the blade (1) is J-shaped, the opening direction of the blade (1) is away from the wheel shaft (4), the blade (1) comprises a suction surface (5) and a pressure surface (6), the side of the blade (1) with a smaller cross-sectional dimension is the suction surface (5), and the side of the blade (1) with a larger cross-sectional dimension is the pressure surface (6), the pressure surface (6) is fixedly connected to the connecting piece (3), the cross-sectional length of the suction surface (5) is 25% to 35% of the chord length, and the thickness of the pressure surface (6) is 1% to 2% of the chord length.

2. A power device for a vertical axis wind turbine according to claim 1, characterized in that: The cross-sectional length of the suction surface (5) is 30% of the chord length, and the thickness of the pressure surface (6) is 1.12% of the chord length.

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