CN103527401A - Method of vertical-shaft wind turbine for improving wind energy utilization through groove opening technology - Google Patents

Abstract

The method of a vertical-shaft wind turbine for improving wind energy utilization through the groove opening technology includes the steps of opening a groove in the position, 35% the chord length away from the front edge, of the lower surface of a blade of the vertical-shaft wind turbine till the tail edge position of the blade, enabling the blade of the wind turbine to be connected with a horizontal supporting rod of a draught fan, and enabling the supporting rod to be connected with a rotating shaft through a connecting disc, wherein the depth of the groove accounts for 60% of the thickness of the blade. The method has the effects and advantages of overcoming the defects of a lift type blade through the groove opening technology, enabling the blade to do positive acting at the full attack angle, reducing the start-up wind speed of the draught fan at the same time, greatly improving use performance of the blade, reducing the start-up wind speed of the draught fan, improving the wind energy utilization coefficient and the like.

Description

Vertical axis windmill is used fluting technology to improve the method for Wind Power Utilization

Technical field: the present invention relates to a kind of method that improves wind mill performance, relate in particular to a kind of blade fluting technology of applying and reach the technological method that wind energy conversion system makes full use of wind energy on vertical axis windmill, belong to the applied technical fields such as Wind Power Utilization.

Background technique: along with environment and energy problem become increasingly conspicuous, the development and utilization of renewable energy sources obtains the attention of countries in the world.Wind energy is occupied very large ratio in the utilization of renewable energy sources, and wind-power electricity generation is as the principal mode of Wind Power Utilization is subject to increasing attention.The modern Large-scale Wind Turbines for being incorporated into the power networks, be mostly horizontal axis wind-driven generator group, and technology is very ripe.But the form of utilizing the earliest of wind energy is exactly vertical axis windmill, it is more late that but vertical axis aerogenerator occurs, be mainly generally believe vertical axis aerogenerator due to people wind energy utilization lower than horizontal axis, thereby cause vertical axis aerogenerator to can not get for a long time paying attention to.Along with the development of lifting wind wheel technology, make the wind energy utilization of vertical axis aerogenerator no longer lower than horizontal axis, and compare with horizontal axis wind-driven generator, it has easy to maintenance, blade design manufacture is simple, and cost is low, does not need advantages such as wind apparatus.

At present pneumatic equipment blades made resistance has two sources: the one, and due to the shearing stress that fluid and body surface friction produce, another is the pressure drag that the asymmetric pressure distribution of body surface produces.If without viscosity flow, the total effect of pressure being subject to before and after object equates, does not therefore have pressure drag.In reality, the effect in boundary layer is similar to and has reduced flow channel (or can be regarded as the equivalent thickness that has increased object), little while making afterbody pressure ratio without viscosity flow, forms pressure drag.While there is separation when flowing, separation zone speed is very little, and from separation point, pressure is substantially constant.Separated by formation separation zone, rear portion and wake flow at object, they are all low pressure areas, will cause very strong pressure drag (separated resistance).Therefore, in order to make resistance reduce just the development in boundary layer to be controlled in minimum limit, and manage to prevent separation.The selections of fairshaped employing and the optimum angle of flare of Diffuser etc., are all based upon in this viewpoint, particularly all the more so in the design of aerofoil profile.For example the thickest position of wing is moved backward, the pressure gradient of wing suction surface is diminished as much as possible, at this moment boundary layer can be more stable, and easily keep laminar flow.The wall shearing stress of laminar boundary layer is little compared with turbulent flow, so formed the little aerofoil profile (laminar flow airfoil) of comparison of resistance.Said method is by the main flow to beyond boundary layer, to flow to control to prevent that Development of Boundary Layer is with separated.In contrast, do not change main flow state and by direct change layer behavior, realize flow separation control and can realize.

Blade fluting technology is to drive deep trouth at fan blade back, within the scope of blade becomes positive incidence with incoming flow, the lift acting that fan blade adopts top airfoil to produce, provide blower fan to drive the moment of torsion of electricity generating device, when blade and incoming flow are during in negative angle of attack, the back fluting of blade becomes resistance type blade, absorbs higher wind energy.Vertical shaft fan lobe numbers is generally more than 3, and such 3 blade top airfoils and lower aerofoil do work in turn, just can provide energy endlessly.

Vertical axis windmill has three kinds of forms of utilizing wind energy at present: 1) lift-type is that application is wider at present, because can there be higher power coefficient; 2) resistance type, tip-speed ratio is less, but easily starting; 3) rise resistance hybrid type, this kind of combination is to combine the drawback of above two kinds, gets its advantage, but under large tip-speed ratio, resistance unit can become the resistance of whole blower fan.If resistance unit is mixed with lift force blade structure, both can solve the negative effect that resistance unit causes, also can improve the deficiency of lift-type blade.Therefore the application development of the blade of this lift-type mixing resistance formula is very potential.

Summary of the invention: the present invention is in order to solve vertical shaft lift type wind energy conversion system in rotary electrification process, the blade that absorbs wind energy rotates with respect to running shaft, and the string of a musical instrument angle of wind direction and blade is along with the angle of swing of wind wheel is periodically variable.Each blade sends useful work only at a very little angular range, when blade positive incidence, does positive work, and negative angle of attack is to do negative work.For a change do this defect of negative work during negative angle of attack, at blade back fluting, make blade when negative angle of attack, also do positive work, and then improve the performance of wind energy conversion system, absorb more wind energy.

For achieving the above object, the technical solution used in the present invention is: vertical axis windmill is used fluting technology to improve the method for Wind Power Utilization, the steps include: on blade of vertical axis wind turbine lower surface apart from leading edge 35% chord length place fluting, until blade trailing edge place; The degree of depth is 60% of vane thickness, and pneumatic equipment blades made is connected with horizontal fan strut, and strut is connected with running shaft by land.

Effect of the present invention and benefit are: the present invention adopts blade fluting technology to make up the deficiency of lift-type blade, make blade do positive work in the full angle of attack, reduced the startup wind speed of blower fan simultaneously, greatly improved blade usability, there is the fan starting of reduction wind speed, improve the advantages such as power coefficient.

Accompanying drawing explanation

Fig. 1 is the structural representation of blade.

Fig. 2 is the plan view of Fig. 1.

Fig. 3 is the structural representation of vertical axis windmill.

Embodiment:

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technological scheme in the embodiment of the present invention is carried out to clear, intactly description, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiments.Give the embodiment in the present invention, those of ordinary skills, not making the every other embodiment who obtains under creative work prerequisite, belong to the scope of protection of the invention.Below in conjunction with technological scheme and accompanying drawing, describe a specific embodiment of the present invention in detail.

As depicted in figs. 1 and 2: look into and get aerofoil profile handbook, choose symmetrical airfoil 0018 for experiment aerofoil profile, blade adopts wooden making, for preventing that the blade intensity of cracking is affected.At blade interior design built-in metal steel member, pre-buried 3 of every blade, and every blade steel part position is the same, with Fan-free rotation imbalance.Blade cracks and guarantees not change the original aerodynamic configuration of aerofoil profile.Ready-made vane group is dressed up to experimental framework, be enclosed within on running shaft, finally connect outside laboratory apparatus and test.Vertical shaft fan application fluting technology, main experimental program is comprised of fan blade 1, slotted opening 2.On blade of vertical axis wind turbine 1 lower surface, apart from leading edge 35% chord length place, slot, until blade trailing edge place; The degree of depth is 60% of vane thickness.

Working principle

In vertical shaft lift type pneumatic equipment blades made when work,, rely on the lift of blade itself to produce power at rotation round tangential force component, and blade is in rotary course, blade with angle of attack incoming flow in continuous variation.Along with the increase of the angle of attack, blade suction surface airflow breakaway is aggravated gradually, and lift reduces gradually, and tangential component also reduces thereupon, and the acting ability of blade also declines thereupon.For blade is done work within the scope of negative angle of attack, adopt blade back fluting, blade is become to resistance type, can increase like this Wind Power Utilization of blade, thereby improve generated energy.

As shown in Figure 3: assembling axle 7 is connected with blower fan experimental setup fixed base, use shaft joint to be connected with measurement fan parameter torsionmeter.Blower fan experimental setup adopts 4 blades, is circumferentially evenly arranged, and has the bolt hole being connected with connecting rod 4 on blade 1, uses bolt 3 to be connected with connecting rod 4, and connecting rod is connected with mounting disc 5 by bolt, forms a blower frame.In the mounting disc of blower frame, there is through hole, be enclosed within on running shaft 6, use jackscrew and axle to fix.Assembling axle 7 is connected with running shaft 6.

Claims (1)

1. vertical axis windmill is used fluting technology to improve the method for Wind Power Utilization, the steps include: on blade of vertical axis wind turbine lower surface apart from leading edge 35% chord length place fluting, until blade trailing edge place; The degree of depth is 60% of vane thickness, and pneumatic equipment blades made is connected with horizontal fan strut, and strut is connected with running shaft by land.

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