RU2261363C2 - Wind power-generating plant with two injection diffuser - Google Patents

Abstract

FIELD: wind power engineering.

SUBSTANCE: proposed wind power-generating plant contains wind motor, booster, electric generator, nacelle, support device with turning mechanism and atmospheric diffuser in form of annular wing. Two independent slots for annular injection arranged in tandem are made on inner wall. First injection is carried out by peripheral part of main air flow getting to wind wheel at end compressor section of blades acting on peripheral part. Said sections of blades are separated by plates from main turbine part of blades and are rotated in cavity of diffuser housing with delivery of air into annular channel found under inner surface of diffuser divided by curved blades to form interblade channels and terminating in first slot of injection.

EFFECT: increased wind energy utilization factor, reduced axial length of diffuser and its cost.

4 dwg

Description

The invention relates to the field of energy, namely to wind turbines.

A known scheme of a horizontal-axis wind turbine with a diffuser having two injection sites in the form of annular slots of external atmospheric air into the boundary layer on the inner surface of the diffuser: one blowing into the annular gap at the entrance to the diffuser, directly in the plane of the wind wheel, the second into the annular gap on the inner surface of the diffuser, downstream (see (1), pp. 134-138, Fig. 4.11). According to this scheme, a Vortec-7 wind turbine was installed and commissioned in New Zealand in 1996 with a 1000 kW electric generator (see (2)).

A well-known manufactured and operating CH Caphom 10 / POL wind turbine with a power of 10 kW (France) with a ring-shaped diffuser without blowing is known (see (3)).

The disadvantage of the scheme, having blown into the boundary layer of outdoor atmospheric air, is the relatively low energy consumption of the injected mass of air, because the amount of fluid motion introduced into the boundary layer is determined by the relatively small kinetic energy of the external air flow and the small difference in static pressures on the outer and outer sides of the diffuser.

The technical result is to increase the utilization of wind energy, reducing the mass and cost of the diffuser. The solution of the task to achieve the stated technical result is as follows.

A wind turbine with a diffuser contains a wind turbine, a multiplier, an electric generator, a nacelle, a support device with a rotation mechanism and an atmospheric diffuser in the form of an annular wing. On its inner wall there are two sequentially located independent slots for annular injection into the boundary layer of outside atmospheric air, the first blowing being carried out by the peripheral part of the main air flow entering the wind wheel, by acting on this peripheral part of the flow by the end compressor sections of the blades separated by plates from the main turbine part of the blades and rotating in the recess of the diffuser body, with the subsequent supply of this air to the annular channel located along d the inner surface of the diffuser, divided by curved blades into separate interscapular channels and ending with the first injection gap.

The diffuser body in its cross section is made in the form of a wing profile and forms a body of revolution, while the inner wall of the diffuser is formed by the convex side of the wing profile and the diffuser has an opening angle α increasing along its length (the so-called diffuser in the form of an annular wing). The maximum value of the opening angle α is limited by the appearance of separation of the boundary layer from the surface of the diffuser wall due to an increase in the positive pressure gradient in the direction of flow. To prevent such a separation in the analogues and prototype, both the outflow of external atmospheric air through the first annular gap into the zone of formation of the boundary layer and the outflow of outside atmospheric air into the second annular gap into the zone before separation of the boundary layer are provided. However, the relatively small momentum of the injected air flows does not significantly reduce the length of the diffuser. To increase the amount of movement of the air mass in the boundary layer (in order to move the flow away or to avoid separation), it is proposed to change and intensify the scheme of the first injection, namely, to form the first injected annular jet due to not only the energy of the incident flow on the atmospheric air gap, but also due to selection a small fraction of the power of the wind turbine. To this end, it is proposed to perform the peripheral part of each blade of a wind turbine of a wind turbine in the form of a compressor section. These peripheral parts of the blades are recessed into an annular niche on the inner wall of the diffuser. The niche does not have a step in its front part and therefore atmospheric air is freely sucked in by the compressor sections of the blades and then pumped into the annular slot channel located inside the diffuser body under its inner surface and starting directly behind the rotating blades, so that the entrance to the channel is the back of the niche . As a result, both the kinetic energy of atmospheric air and some small part of the wind turbine power are supplied to the boundary layer on the inner wall of the diffuser, which prevents flow separation from the wall and, reducing losses in the diffuser, makes the process of increasing the static pressure in it more efficient. As a result, the rarefaction behind the wind turbine increases, its power and, ultimately, the coefficient of utilization of wind energy, and also reduces the axial size of the diffuser and its mass.

Figure 1 shows a schematic structural diagram of a wind turbine with a diffuser having two air blowing into the boundary layer on its inner wall. Figure 2 shows a cross-sectional diagram of a diffuser housing showing the air lines of the first and second blowers. Figure 3 shows a scan of section aa in figure 1, showing the relative position of the blade and the inter-blade channels of the annular portion of the first injection. Figure 4 is a section bb in figure 1, showing a view of the blade and the entrance to the channel of the first injection.

The wind turbine consists of the following main units: wind turbine 1, atmospheric diffuser 5, nacelle 11, multiplier 12, electric generator 13, support 17. Wind turbine 1 has rotary blades (the rotation mechanism in figure 1 is not shown), the peripheral part 3 of which has a profile rotated a certain angle relative to the longitudinal axis of the main part of the blade counterclockwise (figure 3). Between the peripheral (compressor) part 3 of the blade and the main (turbine) part of the blade 2 there is a plate 20 separating them. The diffuser 5 has a housing whose cross section (Fig. 2) is obtained by rotation around its axis of the wing profile. On the inner surface of the diffuser at a certain distance from the inlet there is a niche 4 (Fig. 2) of a triangular cross section in which the peripheral compressor sections of the blades rotate. Niche 4 in its front part at point A has a kink in the wall surface, and not a ledge. The rear part of the aircraft niche is the entrance to the annular channel 6 for the first slotted injection of atmospheric air injected by the peripheral (compressor) part 3 of the blade. The annular channel 6 (FIG. 3) is divided by curved blades 18 into separate interscapular channels 19 with a cross-sectional area increasing in the direction of flow. The inter-blade channels 19 are combined by an annular slot 9 for blowing air into the boundary layer on the inner wall of the diffuser. At the rear of the diffuser there is an annular channel 7 for the second injection through the annular gap 8 of the outside atmospheric air. The body of the diffuser 5 through the power struts 10 is connected to the nacelle 11, which is located at the top of the support 17. To rotate the nacelle together with the diffuser there is a rotary support 15 and a rotation mechanism 16.

Wind turbine works as follows. Using a hydro or electromagnetic drive 14, the wind turbine is oriented by the rotary device 15 to the direction of the wind. The wind flow, energetically acting on the blades 2, spins the wind turbine 1, the rotor of which rotates in the support node 14, as a result of which the generator 13 rotates through the multiplier 12. Atmospheric air flows into the diffuser 5, flowing also to the peripheral parts 3 of the blades 2. Peripheral parts of the 3 blades operate as a low-pressure compressor grill and supply flowing atmospheric air into the slotted annular channel 6. In relative motion (Fig. 3), atmospheric flow flows to the compress ny profile 3 with a speed W ₁ and leaves it with a speed W _2. Having received a peripheral speed (blade rotation speed) U, the flow enters the inter-blade channels 19 with an absolute speed C. Then the flow is rotated with the help of curved blades 18 in a direction close to the axial one, and its speed decreases to a value energetically necessary for injection into the boundary layer on the inner surface of the diffuser to prevent separation of the main stream. The height h of the interscapular slotted annular channel 6 (Fig. 2) at the entrance to the annular gap 9 is determined by the condition h> δ **, where δ ** is the thickness of the pulse loss in the boundary layer on the diffuser wall in front of the annular gap 9. Repeated energy impact on the boundary the layer is produced by means of a secondary slotted injection 7 of outside atmospheric air through an annular channel 8 downstream.

The possibility of carrying out the invention is confirmed by the use of a successfully operating Vortec-7 (2) wind turbine with two ring slotted injections into the atmospheric air diffuser and CH Caphorn 10 / POL (3) wind turbines with a ring wing diffuser.

SOURCES OF INFORMATION

1. "Wind Energy" Ed. D. de Renzo: - Moscow, Energoatomizdat, 1982, pp. 134-138, Fig. 4.11.

2. Bruce Cole. New turbine could offer low cost wind power. "Modem Rotor Systems". August 1977 - p. 27-30.

3. Windpower Monthly, vol. 17, No. 11, November 2001, p. 33.

Claims (1)

A wind turbine with a diffuser containing a wind turbine, a multiplier, an electric generator, a nacelle, a support device with a rotation mechanism and an atmospheric diffuser in the form of an annular wing, on the inner wall of which there are two successively independent slots for annular injection into the boundary layer of external atmospheric air, the first blowing is carried out by the peripheral part of the main air flow entering the wind wheel, by means of the impact on this peripheral part of the flow by the end compressor and sections of the blades separated by plates from the main turbine part of the blades and rotating in the recess of the diffuser body, with the subsequent supply of this air to the annular channel located under the inner surface of the diffuser, divided by curved blades into separate interscapular channels and ending with the first injection gap.

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