CN103939285A

CN103939285A - Method for changing pitch of lift type impeller

Info

Publication number: CN103939285A
Application number: CN201410118359.9A
Authority: CN
Inventors: 赵振宙; 郑源; 李涛; 陈景茹; 叶芬; 赵振宁
Original assignee: Hohai University HHU
Current assignee: Hohai University HHU
Priority date: 2014-03-27
Filing date: 2014-03-27
Publication date: 2014-07-23

Abstract

The invention discloses a method for changing the pitch of a lift type impeller. According to the method for changing the pitch of the lift type impeller, a pitch changing connecting rod used for controlling a blade to move is arranged, so that a pitch angle curve of the blade is a sinusoid. By the adoption of the method for changing the pitch of the lift type impeller, the impeller stills keeps good work at an original azimuth angle with high work, and the phenomenon of stall is avoided; in addition, the angle of attack is effectively increased, and efficiency is improved obviously; finally, according to the prior art, a local area is increased, and the efficiency of the local area may be lowered; however, according to the method for changing the pitch of the lift type impeller, the work ability of the area with the largest work is brought into full play, the work ability of the area with the smallest work is fundamentally improved through the pitch changing technology, and the effect is remarkably improved.

Description

The feather method of lift-type impeller

Technical field

The present invention relates to impeller, the impeller that is particularly useful for for example wind energy conversion system or energy by ocean current generating becomes oar method.

Background technique

Existing lifting upright shaft wind turbine impeller has without to wind yaw system, to advantages such as wind direction adaptation are stronger.But lifting upright shaft wind energy conversion system never, as horizontal-shaft wind turbine, has fast development in large scale computer set product direction, one of its reason is that the aeroperformance of lifting upright shaft wind turbine impeller is not as good as the aeroperformance of horizontal-shaft wind turbine.

Equally, lifting upright shaft impeller also can be used for tidal current energy water turbine, or the hydroelectric water turbine of micro-head, but the water turbine of this vertical shaft is also because the power efficiency not as good as horizontal axis water turbine is high, so commercialization speed is slower.

Summary of the invention

Goal of the invention: a kind of feather method of lift-type impeller is provided, to solve the not good defect of prior art performance, promotes its industrialization process.

Technological scheme: a kind of feather method of lift-type impeller, empennage is set on impeller shaft, and link is in order to control the change oar connecting rod of blade movement on empennage, the propeller pitch angle curve that makes blade is sinusoidal curve or cosine curve.

Described propeller pitch angle curve is: θ=α _maxsin(β), wherein, θ is the propeller pitch angle that blade changes, the azimythal angle that β is blade, α _maxfor the maximum value at blade rotary angle.

Beneficial effect: by adjusting the angle of blade, the present invention can make impeller originally still keeping good acting on the higher azimythal angle of acting, there will not be stall phenomenon; Meanwhile, effectively increase the pneumatic angle of attack, obviously improved efficiency; Finally, prior art only makes regional area increase, and likely reduces this component efficiency, and the present invention gives full play to the acting ability in maximum acting region, make minimum acting ability of doing work region obtain the improvement of essence by becoming oar technology simultaneously, effect improved obvious.

Brief description of the drawings

Fig. 1 is principle schematic of the present invention.

Embodiment

For solving technical problem mentioned above, general technical thought is: according to the aerodynamic characteristic of lifting upright shaft wind energy conversion system, in conjunction with some pneumatic operation characteristics of horizontal-shaft wind turbine, design a kind of lifting upright shaft impeller of feather operation.Its basic principle is: by changing the relative angle of blade in rotary course, thereby reach the object that changes the pneumatic angle of attack of blade, increased to a certain extent exerting oneself of blade.

But, creatively study discovery through inventor: the result of this feather is to have increased the pneumatic angle of attack of part preferably of originally just exerting oneself, and exert oneself weak part still the angle of attack a little less than.Therefore, originally exerted oneself local because the pneumatic angle of attack is larger preferably, in feather process, continue to increase, easily there is stall phenomenon and do not reach the object of feather, because feather is less in the weak part feather of exerting oneself, do not reach to improve yet and exert oneself compared with the power efficiency of weak part blade simultaneously.In a word, the existing feather method of improving aeroperformance is improved the poor effect of upright shaft wind motor impeller performance.

Definition blade and empennage are 0 ° and 360 ° of orientation when nearest, are 180 ° of orientation farthest time, are 90 ° of orientation through 0 ° of position rotation through 90 ° of positions, are 270 ° of orientation through 90 ° of positions of 180 ° of orientation rotations.Above-mentioned several azimythal angle is typical azimuthal angle beta, is also changeless azimuthal angle beta.

Definition centered by blade fixed axle, be rotated counterclockwise on the occasion of.Four azimythal angles, determine that blade rotary angle is that 180 ° and 0 ° of azimythal angle are 0 °, are negative α 90 ° of azimuthal angle of swing _maxvalue is positive α 270 ° of azimuthal angle of swing _maxvalue, α here _maxvalue is the static stall angle of attack of vane airfoil profile.Like this, definition θ is the propeller pitch angle that blade changes, and β is one week different azimythal angle of blade rotary.

As shown in Figure 1, empennage 4 is set on impeller shaft 1, and arranges in order to control the change oar connecting rod of blade movement, the propeller pitch angle curve 2 that makes blade 3 is sinusoidal curve or cosine curve.Become oar connecting rod and be used for controlling the change oar position of blade at diverse location.Empennage is used for locating, and empennage is opened up under the effect of wind resistance, and empennage belongs to downwind position all the time, and the round end of the blade person of remaining blade moves with fine stern.Blade is under the effect of wind lift, and along (or counterclockwise) rotation clockwise, in a polling system, direction and orientation are substantially definite so all the time.

Blade was along one week movement locus θ=α _maxsin (β), makes blade not become oar when 0 ° of azimythal angle and the 180 ° of azimythal angles by becoming oar connecting rod, becomes vane angle maximum in the time of 90 ° and 270 °.Become like this angle of attack curve θ=α of vane angle _maxsin (β), with the pneumatic angle of attack curve of blade a=α itself _maxcos (β), just in time forms complementary.The two stack sum made within the scope of the whole week, and the pneumatic angle of attack all remains on higher level.

180 ° of positions, become vane angle and be 0 °, still, due to tangential wind velocity U and the synthetic effective velocity R of incoming flow wind speed W and the angle of attack maximum of blade formation, distance between lift L and wind wheel rotating shaft is larger, and the moment of generation is also larger, now has good aeroperformance.Be positive α at 270 ° of angle changings _maxangle, although the lift of this instantaneous generation and impeller axis are angle is 0 °, as long as blade continues motion or a few degrees before arriving 270 °, there is a larger angle of attack, this angle of attack is more much larger than the angle of attack at fixedpiston angle, the extraordinary aerodynamic characteristic of instantaneous generation.Although do not produce moment 270 ° of positions, the scope of impact becomes the long-pending distribution of shapes of zero layer, so affect minimum.The principle of 90 ° of positions is identical with the acting principle of 270 ° of positions.By such change oar, blade can rotation one week any one azimythal angle all there is the higher pneumatic angle of attack, higher raising the overall aeroperformance of lifting upright shaft impeller.The feather method of this impeller is also applicable in low-head hydraulic generating and marine tidal-current energy water turbine.

More than describe the preferred embodiment of the present invention in detail; but the present invention is not limited to the detail in above-mentioned mode of execution, within the scope of technical conceive of the present invention; can carry out multiple equivalents to technological scheme of the present invention, these equivalents all belong to protection scope of the present invention.

It should be noted that in addition each the concrete technical characteristics described in above-mentioned embodiment, in reconcilable situation, can combine by any suitable mode.For fear of unnecessary repetition, the present invention is to the explanation no longer separately of various possible compound modes.

Claims

1. a feather method for lift-type impeller, is characterized in that, arranges in order to control the change oar connecting rod of blade movement, and the propeller pitch angle curve that makes blade is sinusoidal curve.

2. the feather method of lift-type impeller as claimed in claim 1, is characterized in that, described propeller pitch angle curve is: θ=α _maxsin(β), wherein, θ is the propeller pitch angle that blade changes, the azimythal angle that β is blade, α _maxfor the maximum value at blade rotary angle.