JP6677783B1 - Propeller device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly efficient propeller device capable of realizing a cut-in wind speed from a low wind speed as compared with a conventional one. A propeller device includes a main propeller having a plurality of main blades fixed to a center of rotation, and a plurality of auxiliary blades fixed to the center of rotation at different positions separated from the main propeller by a first distance. With a sub-propeller, each of the plurality of main blades has a shape in which the chord length becomes shorter from the rotation center toward the outer circumference, and each of the plurality of sub blades goes from the rotation center toward the outer circumference. Has a shape in which the chord length increases. [Selection diagram] Fig. 1

Description

  The present invention relates to a propeller device including a main propeller and a sub-propeller.

  As a technique related to a conventional propeller device for a generator, there is a windmill rotor including a hub, a spinner, and at least two main blades (for example, see Patent Document 1). In the wind turbine rotor according to Patent Literature 1, at least one sub-blade is provided so as to cover at least a part of a region between blade roots of two adjacent main blades.

  Such an auxiliary blade extends radially outward of the wind turbine rotor from the hub or the spinner, and has a configuration in which the blade length is shorter than that of the main blade. Further, the cord length of the sub-blade decreases monotonously from the blade side toward the splash tip side.

Further, the sub-blade according to Patent Document 1 has a relationship represented by the following expression (1).
Copt-Cmain ≦ Cs ≦ 0.5 Copt (1)

Here, each of Copt, Cmain, and Cs in the above equation (1) means the following contents.
Copt: Optimum code length of the main blade at the radial position r of the wind turbine rotor corresponding to the blade length direction position x Cmain: Code length of the main blade at the radial position r Cs: Code length

  Then, the optimum code length Copt of the main blade is expressed by the following equation (2).

  As a result, the wind turbine rotor according to Patent Document 1 can improve the aerodynamic performance in the inner section as the entire wind turbine rotor, and can effectively improve the blade efficiency of the wind turbine rotor.

JP-A-2005-86822

  However, the related art has the following problems. The blade shape of the wind turbine rotor according to Patent Document 1 is of a type in which both the main blade and the sub-blade have a relatively high peripheral speed ratio and exhibit performance at a certain high rotation. Therefore, the blade of the wind turbine rotor according to Patent Literature 1 is not a blade that generates a large torque at low wind speeds and low rotation speeds and can greatly improve the cut-in wind speed.

  On the other hand, depending on the installation environment, it is required to generate a desired torque and obtain an appropriate power generation amount at low wind speed and low rotation.

  The present invention has been made in order to solve the above-described problem, and has an object to obtain a high-efficiency propeller device for a generator that can realize a cut-in wind speed from a low wind speed as compared with the related art. I do.

  A propeller device according to the present invention includes a main propeller having a plurality of main blades fixed to a center of rotation, and a plurality of sub-blades fixed to the center of rotation at different positions separated from the main propeller by a first distance. A main propeller, and each of the plurality of main blades has a shape in which the chord length becomes shorter from the center of rotation to the outer peripheral side, and each of the plurality of sub blades is closer to the outer peripheral side from the center of rotation. Has a shape in which the chord length becomes longer in accordance with

  According to the present invention, a configuration is provided in which the torque of the main blade can be assisted by the torque of the auxiliary blade during low rotation. As a result, it is possible to obtain a high-efficiency propeller device for a generator capable of realizing a cut-in wind speed from a low wind speed as compared with the related art.

1 is a front view showing a propeller device according to Embodiment 1 of the present invention. FIG. 2 is a side view showing the propeller device of FIG. 1 according to Embodiment 1 of the present invention. It is a figure which shows the characteristic of the generated torque and cut-in wind speed of the propeller apparatus which concerns on Embodiment 2 of this invention. FIG. 14 is a diagram illustrating characteristics of generated torque of a propeller device according to Embodiment 3 of the present invention. FIG. 14 is an explanatory diagram relating to a generated torque of a main propeller according to Embodiment 4 of the present invention. FIG. 13 is an explanatory diagram showing a positional relationship between a sub propeller and a support post 5 when a propeller device according to a fifth embodiment of the present invention is installed as a downwind type. It is a figure which shows the characteristic of the generated torque of the propeller apparatus which concerns on Embodiment 5 of this invention.

  Hereinafter, preferred embodiments of a propeller device according to the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a front view showing a propeller device according to Embodiment 1 of the present invention. FIG. 2 is a side view showing the propeller device of FIG. 1 according to Embodiment 1 of the present invention.

  Propeller devices for generators convert the energy of a fluid stream into rotational energy. Examples of the fluid include air and water. The propeller device for a generator includes a main propeller 1 rotatably provided and a sub-propeller 2 installed upstream of the main propeller 1. The main propeller 1 and the sub-propeller 2 are connected to a rotating shaft of a generator (not shown).

  The main propeller 1 has a columnar rotation center 3 and a plurality of main blades 1 a provided in the rotation center 3. In the following description, the radial direction is the radial direction of the rotation center 3. Further, the circumferential direction is a circumferential direction about the rotation center portion 3. Further, the axial direction is the axial direction of the rotation center 3.

  The main blade 1a is fixed to the rotation center 3 so as to extend radially outward from the rotation center 3. In FIG. 1, three main blades 1a are arranged at equal intervals in the circumferential direction. Further, as the three main blades 1a extend in the radial direction, the circumferential width of the main blades 1a decreases. That is, in the main blade 1a, in the circumferential direction, the chord length, which is the length of a straight line connecting the leading edge and the trailing edge of the airfoil, becomes shorter toward the outer peripheral side.

  The main propeller 1 having such a shape rotates in the circumferential direction. As the main propeller 1 rotates, the rotating shaft of the generator rotates. The rotating shaft of the generator extends horizontally. In other words, the generator used for the propeller device is configured as a horizontal axis generator.

  On the other hand, similarly to the main propeller 1, the sub-propeller 2 has a column-shaped rotation center portion 3 and a plurality of sub-blades 2a provided in the rotation center portion 3. The auxiliary propeller 2 is fixed to the rotation center 3 so as to extend radially outward from the rotation center 3. In FIG. 1, three sub-blades 2a are arranged at equal intervals in the circumferential direction. Further, as for the three sub-blades 2a, the width in the circumferential direction of the sub-blade 2a is increased as it extends in the radial direction. That is, in the sub-blade 2a, in the circumferential direction, the chord length, which is the length of a straight line connecting the leading edge and the trailing edge of the airfoil, becomes longer toward the outer peripheral side.

  Then, as shown in FIG. 1, the radial center line of the sub-propeller 2 has an angle θ with respect to the radial center line of the main propeller 1. As shown in FIGS. 1 and 2, the main propeller 1 having the radius R1 and the sub-propeller 2 having the radius R2 are arranged with a distance L in the axial direction. The main propeller 1 and the sub-propeller 2 having such a shape and arrangement rotate in the circumferential direction in synchronization with each other.

  Here, the main propeller 1 is a lift-type high-rotation type propeller. On the other hand, the auxiliary propeller 2 having a lower peripheral speed ratio than the main propeller 1 is a low-rotation type propeller. Therefore, according to the propeller device according to the first embodiment, by attaching such two propellers coaxially, the propeller efficiency at the time of low rotation can be improved. As a result, it is possible to provide a propeller device for a generator that realizes a cut-in wind speed from a low rotation.

  Note that the cut-in wind speed is a wind speed at which the main propeller 1 and the sub-propeller 2 of the propeller device start rotating and can start power generation.

Embodiment 2 FIG.
In the second embodiment, the difference in the characteristics of the propeller device depending on the angle θ shown in FIG. 1 will be described in detail.
FIG. 3 is a diagram illustrating characteristics of generated torque and cut-in wind speed of a propeller device according to Embodiment 2 of the present invention. More specifically, FIG. 3 shows a generator when the angle θ between the radial center line of the main propeller 1 and the radial center line of the sub-propeller 2 is changed in the range of 0 ° to 100 °. FIG. 2 shows characteristics of a generated torque and a cut-in wind speed of a propeller device for use.

  As the torque, the generated torque at a wind speed of 8 m / s and 1000 rpm (at high wind speed and high rotation) is quantified as the maximum torque 100, and the scale is attached to the left vertical axis in FIG. Further, the cut-in wind speed is expressed as a numerical value with the minimum wind speed being 1 when the torque at the start of power generation is 40 cN · m, and the scale is attached to the vertical axis on the right side of FIG. From the characteristics of FIG. 3, it can be seen that the generated torque is the largest when θ = 60 ° at high wind speed and high rotation. As for the cut-in wind speed, it can be seen that the cut-in wind speed is lowest when θ = 50 °.

  In general, whether the cut-in wind speed is important or the maximum torque is important depends on the installation location and the installation conditions of the generator propeller device. For example, when a propeller device for a generator is installed in a city where the wind does not blow much, the cut-in wind speed is emphasized. On the other hand, when the propeller device for the generator is originally installed in a windy coastal area or a mountainous area, the maximum torque is emphasized. From the results shown in FIG. 3, when the maximum torque and the minimum cut-in wind speed are allowed to deteriorate to about 5%, θ is in a range of 45 ° to 65 °.

  As described above, according to the propeller device according to the second embodiment, by changing the angle θ, the cut-in wind speed is emphasized and the proper torque is emphasized according to the maximum torque in accordance with the installation location and installation conditions of the propeller device. Characteristics can be realized.

  Furthermore, by preparing a mechanism that can adjust the angle of the main propeller and the sub-propeller, using the same parts, the cut-in wind speed is emphasized according to the installation location and installation conditions of the propeller device, and It is possible to cope with appropriate characteristics based on the emphasis on the maximum torque.

Embodiment 3 FIG.
In the third embodiment, the difference between the torque characteristics according to the radius R2 shown in FIG. 1 and the distance L shown in FIG. 2 will be described in detail.
The auxiliary propeller 2 is arranged more windward than the main propeller 1. Here, the relationship between L / R2, which is the ratio of the distance L between the center of gravity of the propeller of each of the main propeller 1 and the auxiliary propeller 2 and the radius R2 of the auxiliary propeller 2, and the torque generated by the propeller device will be described.

  FIG. 4 is a diagram illustrating characteristics of generated torque of a propeller device according to Embodiment 3 of the present invention. More specifically, FIG. 3 shows the characteristics of the generated torque of the propeller device when L / R2 is changed. Note that the vertical axis of FIG. 4 is a numerical value of the torque, with the generated torque at the time of L / R2 dimensions not affected by the sub-propeller 2 as 1. As shown in FIG. 4, when L / R2 was 0.2, a torque reduction of about 5% was measured.

  It is important that the sub-propeller 2 realizes a low cut-in wind speed by generating a large torque at low wind speed and low rotation speed, and does not deteriorate the performance of the main propeller 1 at high wind speed and high rotation speed. In order to eliminate the influence on the performance deterioration of the main propeller 1, as shown in FIG. 4, the ratio between the distance L and the radius R2 may be set so that L / R2 becomes 0.3 or more.

  However, in consideration of miniaturization of the propeller device, the torque reduction can be suppressed to within 5% by setting L / R2 to 0.2 or more. As a result, a small-sized propeller device with high power generation efficiency can be realized.

  In the configuration of the propeller device according to the third embodiment, the sub-propeller 2 is installed on the leeward side, and the main propeller 1 is installed on the leeward side. In the case of a downwind type wind power generator, the props for supporting the main propeller 1 and the sub-propeller 2 are arranged on the windward side of these propellers, so that the props deteriorate the propeller performance.

  In particular, the main propeller 1 having a high peripheral speed at the blade tip tends to be greatly affected by the columns. Therefore, in the configuration of the propeller device according to the third embodiment, the main propeller 1 is installed away from the support. This makes it possible to reduce the influence of the columns and obtain an effect of improving the deterioration of the propeller performance, thereby realizing a propeller device capable of high-efficiency power generation.

Embodiment 4 FIG.
In the fourth embodiment, the torque generated by the main propeller 1 according to the radial distance will be described in detail.
FIG. 5 is an explanatory diagram relating to the generated torque of main propeller 1 according to Embodiment 4 of the present invention. Specifically, FIG. 5 shows a torque ratio of a cross section at each diameter with respect to a ratio (R / R1) between a radial distance R from the rotation center portion 3 and a diameter R1 of the main propeller 1. It is. R / R1 = 1 becomes the tip of the propeller, and R / R1 = 0 becomes the center of the propeller.

  From the results in FIG. 5, it can be seen that the main propeller 1 accounts for about 30% of the tip and about 70% of the entire generated torque. Therefore, by setting the radius R2 of the sub-propeller 2 located on the windward side to be 70% or less of the radius R1 of the main propeller 1, the sub-propeller 2 interferes with the performance of the main propeller 1 at high wind speed and high rotation. , And a propeller device for a generator that realizes a low cut-in wind speed can be obtained.

  Note that, as the radius R2 of the sub-propeller 2 is as large as possible within a range of 70% of the main propeller 1, a smaller low cut-in wind speed can be realized. On the other hand, the smaller the radius R2 of the auxiliary propeller 2 is, the less the disturbance to the main propeller 1 is, so that the performance at high wind speed and high rotation can be improved.

  Therefore, by designing the main propeller 1 and the sub-propeller 2 so that the ratio between the radius R1 and the radius R2 becomes an appropriate value depending on the installation place and the installation conditions of the propeller device, the installation is performed according to the installation place and the installation conditions. An optimal propeller device can be realized.

Embodiment 5 FIG.
In the fifth embodiment, the adjustment of the distance between the column and the sub-propeller 2 will be described in detail.
FIG. 6 is an explanatory diagram showing a positional relationship between the sub-propeller 2 and the column 5 when the propeller device according to Embodiment 5 of the present invention is installed as a down-window type. As shown in FIG. 6, the column 5 has a diameter d, and is arranged such that the distance from the auxiliary propeller 2 located on the windward side in the axial direction is the distance X. Note that a generator and the like are housed in the nacelle 4 provided on the upper part of the column 5, and the main propeller 1 and the sub-propeller 2 are connected to the rotating shaft of the generator.

  FIG. 7 is a diagram showing characteristics of generated torque of the propeller device according to Embodiment 5 of the present invention. More specifically, FIG. 7 shows a measurement result of the generated torque of the propeller device when d / X is changed.

According to the measurement results of FIG. 7, when the ratio (d / X) of the distance X between the support 5 and the sub-propeller 2 to the diameter d of the support 5 is 0.85 or less, the influence of the support 5 is substantially reduced. Can be eliminated. Actually, the diameter d of the column 5 needs to have sufficient strength in the environment in which it is used, and the diameter d of the column 5 is determined from the strength surface. Therefore, the distance X between the column 5 and the sub-propeller 2 can be defined from the diameter d of the column 5 as in the following equation (3).
X ≧ d / 0.85 (3)

  By defining the distance X according to the above equation (3), it is possible to obtain an appropriate distance X for the diameter d of the column 5 determined according to the installation environment. As a result, a small and highly efficient propeller device for a generator can be realized. Also, by realizing the miniaturization, the components of each part are advantageous in terms of strength, and the weight can be reduced.

  In the above-described first to fifth embodiments, a case has been described in which the plurality of main blades 1a and the plurality of sub-blades 2a are each configured as three blades as illustrated in FIG. However, the number of the plurality of main blades 1a and the plurality of sub-blades 2a is not limited to three. Even if the number of the main blades 1a and the number of the sub-blades 2a are two or four or more, the chord length becomes shorter as each of the main blades moves from the center of rotation to the outer periphery. And each of the plurality of sub-blades has a shape in which the chord length becomes longer from the center of rotation to the outer peripheral side, whereby the same effect as in the case of three blades can be obtained.

  1 Main propeller, 1a main blade, 2 sub-propeller, 2a sub-blade, 3 rotation center, 4 nacelle, 5 columns.

Claims (5)

A main propeller having a plurality of main blades fixed to the center of rotation,
A sub-propeller having a plurality of sub-blades fixed to the rotation center at a position separated by a distance L from the main propeller;
Each of the plurality of main blades has a shape in which the chord length becomes shorter as going from the rotation center portion to the outer peripheral side,
The propeller device, wherein each of the plurality of sub-blades has a shape in which a chord length becomes longer from the center of rotation to an outer peripheral side. The plurality of main blades are constituted by three main blades arranged at intervals of 120 °,
The plurality of sub-blades are configured by three sub-blades arranged at 120 ° intervals,
The propeller device according to claim 1, wherein an angle θ between a radial centerline of the main propeller and a radial centerline of the sub-propeller is in a range of 45 ° to 65 °. The auxiliary propeller is arranged on the windward side with the distance L from the main propeller,
3. The propeller device according to claim 1, wherein when a radius of each of the plurality of sub-blades is a radius R <b> 2, a ratio L / R2 between the distance L and the radius R <b> 2 is 0.2 or more. 4. The propeller device according to claim 1, wherein a radius of the auxiliary blade is equal to or less than 70% of a radius of the main blade. The auxiliary propeller disposed on the windward side with respect to the main propeller, further disposed on the windward side with a distance X therebetween, further comprising a support column for supporting the main propeller and the auxiliary propeller,
The propeller device according to any one of claims 1 to 4, wherein a ratio d / X is 0.85 or less when a diameter of the support is a diameter d.

Images