WO2002090777A1

WO2002090777A1 - Blower and air conditioner with the blower

Info

Publication number: WO2002090777A1
Application number: PCT/JP2001/011317
Authority: WO
Inventors: Zhiming Zheng; Jiro Yamamoto
Original assignee: Daikin Industries, Ltd.
Priority date: 2001-04-26
Filing date: 2001-12-25
Publication date: 2002-11-14
Also published as: EP1382856A4; AU2002217482B2; DE60118103D1; TW524928B; CN1201090C; EP1382856B1; EP1382856A1; HK1061707A1; CN1449472A; ES2263554T3; DE60118103T2

Abstract

A blower, comprising an impeller having a plurality of blades (3) installed on the outer periphery of a hub (2), wherein the specific areas (Q) of the blades (3) extending, in a specified width, in a vane span direction along the trailing edges (3b) of the blades (3) are bent to a negative pressure surface (3f) side, whereby the separation of air flow becomes hard to occur on the negative pressure surface (3f) of the blades (3) to suppress the disturbance of a wake (A0), the stream of the air flow discharged rearward from the trailing edges (3b) becomes smooth on the pressure surface (3e) side to reduce the disturbance, and thus the width of the wake (A0) is reduced to improve the aerodynamic characteristics of the blades.

Description

Description Blower and air conditioner equipped with the blower

The present invention relates to a blower characterized by a blade structure and an air conditioner including the same. Background art

Figure 17 shows a conventional general-purpose axial blower Z. Is shown. This axial flow blower Z. , A plurality of blades 23, 23,... Are radially arranged on the outer periphery of a hap 22, and the impeller 21 is rotationally driven by a motor 24. The bell mouth 25 is arranged so as to surround the. Further, as shown in FIGS. 18 and 19, the impeller 23 of the impeller 21 is a forward wing whose front edge 23 a is advanced forward in the rotational direction, and its cross section is streamlined. It is a thick wing having a shape, and is attached to the hub 22 at a predetermined attachment angle.

Further, as shown in FIG. 19, the blade 23 has a curved form having an appropriate “warpage” in the chord direction, and the concave side has a pressure surface 23 c and the convex side has a suction surface 2. 3d. Then, when the impeller 21 rotates, as shown in FIG. 20, the airflow flowing from the leading edge 23 a side of the blade 23, after colliding with the leading edge 23 a, It flows separately to the pressure surface 23c side and the suction surface 23d side, and then is discharged backward from the edge 23b side.At this time, the pressure is raised by the lift action on the pressure surface 23c, It is blown out in the direction of arrow A.

By the way, the conventional axial blower Z. In FIG. 19, as shown in FIG. 19, the “warp” of the blade 23 was generally continuous in the same direction from its leading edge 23 a to its trailing edge 23 b. This is because the "warp" generates a lift effect and the air flow is boosted, so it is effective to increase the range of the "warp" as much as possible to obtain a higher static pressure. It is based on a design philosophy that emphasizes the static pressure characteristics of blowers. However, when the blade 23 has such a configuration that its “warp” is continuous from the leading edge 23 a to the trailing edge 23 b, as described below, the trailing edge 2 Wake A discharged backward from 3b. This increases the width of the blades 23, deteriorating the aerodynamic characteristics of the blades 23, and lowering the blowing efficiency.

That is, since the convex surface is continuous on the negative pressure surface 23 d side of the blade 23, the boundary on the negative pressure surface 23 d increases from the leading edge 23 a to the trailing edge 23 b. since the layer is developed following the second, at the trailing edge 2 3 b vicinity of the air flow flowing through the suction surface 2 3 d side, flaking occurs in the airflow a ₂ that flows along the negative pressure surface 2 3 d, the result The wake A discharged behind the trailing edge 23b. Is a stable and turbulent flow. On the other hand, on the pressure surface 23 c side of the blade 23, the airflow blowing direction at the trailing edge 23 b (that is, the tangential direction to the curved surface near the trailing edge 23 b) and the rotation direction of the blade 23 Of the airflow flowing on the pressure surface 23c side, the airflow flowing along the pressure surface 23c and discharged backward from the trailing edge 23b is the trailing edge. Immediately after the release from 23 b, the blade is deflected along the blade rotation direction, so that the flow becomes unstable and turbulence is likely to occur. The wake A. The turbulence is promoted, and the width in the blade thickness direction, that is, the wake width S increases.

As a result, in the blade 23, the aerodynamic resistance increases, which causes a reduction in the blowing efficiency of the entire blower, and the power consumption of the motor 24 increases by an amount corresponding to the reduction in the blowing efficiency. Things.

Such a problem of an increase in power consumption of a blower is relatively easy to recognize when the blower is used alone, but for example, a blower is incorporated as one of its components, such as an air conditioner. Since the power consumption of the blower is very small compared to the power consumption of other components such as the compressor, the power consumption of the entire air conditioner is examined from the viewpoint of energy saving. In such cases, compressors with higher power consumption attracted more attention, and the power consumption of blowers was rarely taken up as a problem.

However, with the increasing social needs for environmental protection and energy efficiency in recent years, blowers are also required to be energy-saving. It has been requested. Disclosure of the invention

Accordingly, the present invention has been made to provide a blower that achieves high efficiency by improving the blade structure, and an air conditioner equipped with the blower.

In order to solve a powerful problem, a blower according to the present invention is a blower including an impeller in which a plurality of blades are radially mounted on the outer periphery of a hap, wherein each of the blades is disposed at a trailing edge of the blade. It is characterized that a specific area extending along the blade span direction with a predetermined width is curved toward the suction side.

With this configuration, the following effects can be obtained.

(a) On the negative pressure side of the blade! As a result, airflow separation is less likely to occur due to the reduced area of the convex surface that promotes the development of the boundary layer, and turbulence in the wake is suppressed. On the other hand, on the pressure surface side of the blade, the flow of the airflow discharged from the trailing edge to the rear is smooth and turbulent due to the decrease in the angle difference between the airflow blowing direction at the trailing edge and the rotating direction of the blade. Less. As a synergistic effect of these two, the wake width of the wake discharged from the trailing edge of the blade is reduced as much as possible, and the aerodynamic characteristics of the blade are improved accordingly. As a result, high efficiency of the blower is realized, and power consumption is reduced by the increased efficiency, and energy saving is improved.

(b) Since only a specific area on the trailing edge side of the blade is curved toward the suction side, a reduction in the lift effect on the pressure side can be suppressed as small as possible. As a result, the effect described in the above (a) can be secured while suppressing the decrease in the static pressure characteristic as much as possible, and it becomes possible to achieve both high efficiency and energy saving of the blower. And other effects can be obtained.

The above-mentioned effect can be obtained even when the blade is configured to have a substantially uniform blade thickness from the leading edge to the trailing edge, or when the cross section of the blade has a streamline shape. .

Further, the air conditioner according to the present invention is characterized in that, in the air conditioner including the heat exchanger and the blower, the blower having the above-described configuration is applied as the blower. This air conditioner has high efficiency and energy saving by having the blower of the above configuration. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional view of a main part of an axial blower according to a first embodiment of the present invention. FIG. 2 is a front view of the impeller shown in FIG.

FIG. 3 is a cross-sectional view taken along the line II-II of FIG.

FIG. 4 is an explanatory diagram of an airflow state flowing on the blade surface.

FIG. 5 is a cross-sectional view of a main part of a mixed flow blower according to a second embodiment of the present invention. FIG. 6 is a front view of the impeller shown in FIG.

FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG.

FIG. 8 is a front view of an outdoor unit of an air conditioner equipped with an axial blower.

FIG. 9 is a sectional view taken along the line IX-IX of FIG.

FIG. 10 is a sectional view taken along line XX of FIG.

FIG. 11 is a sectional view showing another embodiment of the blade.

FIG. 12 is a cross-sectional view showing another embodiment of the blade.

FIG. 13 is a sectional view showing another embodiment of the blade.

Fig. 14 is a characteristic diagram of “air flow-static pressure” of the blower.

Fig. 15 is a characteristic diagram of “air volume versus total pressure efficiency” of the blower.

Figure 16 is a characteristic diagram of the "air volume uniaxial power" of the blower.

FIG. 17 is a sectional view of a main part of a conventional axial blower.

FIG. 18 is a front view of the impeller shown in FIG.

FIG. 19 is a cross-sectional view of XIX_XIX of FIG.

FIG. 20 is an explanatory diagram of an airflow state flowing over the blade. BEST MODE FOR CARRYING OUT THE INVENTION

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 13 and FIGS. 14 to 16. Similar parts in FIGS. 1 to 13 are denoted by the same reference numerals.

(First Embodiment) FIG. 1 shows an axial blower according to a first embodiment of the present invention. The axial blower _Zt is a so-called “propeller fan”, and has a plurality of (three in this embodiment) blades 3, 3, 3 radially attached to the outer periphery of the hub 2 at a predetermined mounting angle. The impeller 1 is rotatably driven by a motor 4, and a bell mouth 5 is arranged around the outer periphery of the impeller 1 so as to surround the impeller 1.

As shown in FIGS. 2 and 3, the blade 3 of the impeller 1 is a “advanced wing” whose front edge 3 a extends forward in the rotation direction, has a relatively large blade thickness, and This wing thickness is a so-called “air-foil wing” in which the thickness gradually decreases from the leading edge 3 a to the trailing edge 3 b.The wing thickness has a predetermined “warp” in the chord direction. The suction surface is 3 f.

The most characteristic point of the blade 3 is that the blade 3 has a region extending along the trailing edge 3 b at a predetermined width in the blade span direction along the trailing edge 3 b (in FIG. 1 to FIG. 3, The region near the trailing edge 3b from the line L) is defined as a specific region Q, and this specific region Q is a point that is curved toward the negative pressure surface 3f. Therefore, in the blade 3 of this embodiment, the direction of the “warp” is reversed between the leading edge 3a and the trailing edge 3b near the region line L. This form of “warp” is different from the conventional blade 23 shown in FIG. 19 in which “warp” in the same direction is continuous from the leading edge 23 a to the trailing edge 23 b. It is a completely different and novel form.

In the axial flow blower Zi including the impeller 1 having the blades 3 having such a new specific configuration, the following specific functions and effects can be obtained.

That is, as shown in FIG. 4, when the impeller 1 rotates, the pressure surface 3 e and the suction surface 3 f of the blade 3 respectively extend from the leading edge 3 a side to the trailing edge 3 b side along the surfaces. airflow and the airflow A ₂ flows toward the results. Then, of the two air flow AA _2, the airflow A ₂ that flows along the upper Symbol suction surface 3 f is detached at the trailing edge 3 b near wake of unstable turbulent flow A. Is generated. Meanwhile, the airflow flowing along the pressure surface 3 e, after which the rear edge 3 b emitted backward, merges with the downstream A _0.

In this case, in the axial-flow blower of this embodiment, as described above, the specific region Q set on the back 3b side of the blade 3 is curved toward the negative pressure surface 3f, The suction surface 3 f it's only after flow separation area of the airflow A ₂ at the trailing edge 3 b side is reduced in side A. Flow is suppressed. On the other hand, on the pressure surface 3e side, the specific region Q is curved toward the negative pressure surface 3f side, so that the rearward direction of the airflow at the trailing edge 3b approaches the rotation direction of the blades 3 and angle difference therebetween is reduced, its Re only release backward airflow becomes smoother, which less able to promote even the disturbance merges with the rear stream a _0, stability much of the rear stream a ₀ Therefore, the increase of the wake width S is suppressed.

As a result, the aerodynamic characteristics of the blades 3 are improved by an amount corresponding to the suppression of the increase of the wake width S, and the axial blower is improved in efficiency, and the power consumption is increased by the increase in efficiency. It will decrease and the energy saving will be improved.

Further, in this embodiment, as described above, only the specific region Q on the trailing edge 3 b side of the blade 3 is curved toward the negative pressure surface 23 d side. The reduction of the lift effect of the pressure surface 3e due to the setting of the above is suppressed as small as possible, and the static pressure characteristics are favorably maintained.

As described above, in the axial blower according to this embodiment, the efficiency is improved by an extremely simple and inexpensive configuration in which the specific region Q on the trailing edge 3 b side of the blade 3 is curved toward the negative pressure surface 3 f side. And energy conservation.

FIGS. 14 to 16 show the results of various performance tests performed to confirm the above effects in the axial blower of this embodiment.

FIG. 14 shows a characteristic diagram of “air flow-static pressure”, in which a curve ai represents the characteristic of the axial flow fan of the above embodiment, and a curve L bi represents the characteristic of the conventional axial flow fan. It is shown. From the “air flow-static pressure” characteristic diagram of FIG. 14, in the axial flow blower Z i of the above embodiment, the specific area Q on the trailing edge 3 b side of the blade 3 is curved toward the negative pressure surface 3 f side. As a result, the effective area of the pressure surface 3 e, that is, the area of the part related to the air pressurizing action is reduced, and the static pressure performance is somewhat lower than that of the conventional structure. I understand.

Figure 1 5 is a view illustrating the "air volume one total pressure efficiency" characteristic graph, curve L a ₂ is the axial-flow fan of the embodiment characteristic, curve L b ₂ is a characteristic of an axial blower having a conventional structure , Each is shown. From the characteristic diagram of “air volume-total pressure efficiency” in FIG. 15, it is quicker that the axial flow fan of the above embodiment has higher total pressure efficiency than the conventional axial flow fan.

Figure 1 6, there is shown an "air volume uniaxial power" characteristic graph, characteristic curve L a ₃ are axial-flow fan of the implementation form, the curve L b ₃ properties of the axial flow fan of the conventional structure, Each is shown. It can be seen from the characteristic diagram of “air flow uniaxial power” in FIG. 16 that the axial power of the axial blower of the above embodiment is much lower than that of the conventional axial blower.

Thus, in the axial blower of this embodiment, the static pressure performance is slightly lower than that of the conventional structure, but still maintains high performance, while both the total pressure efficiency and the shaft power are higher than those of the conventional structure. In particular, the superiority of the shaft power is remarkable. Therefore, when these performances are considered in comparison, the axial flow blower of this embodiment has a It can be said to be highly efficient and excellent in energy saving.

(Second embodiment)

FIG. 5 shows a mixed flow blower Z ₂ according to a second embodiment of the present invention. The mixed flow blower Z ₂ includes an impeller 1 having a plurality of (four in this embodiment) blades 3, 3,... Radially mounted at a predetermined mounting angle on the outer periphery of a truncated conical hub 2. The impeller 1 is rotatably driven by a motor 4, and a bell mouth 5 is arranged around the impeller 1 so as to surround the impeller 1.

As shown in FIGS. 6 and 7, the blade 3 of the impeller 1 is a “advanced wing” whose front edge 3 a extends forward in the rotation direction, has a relatively small blade thickness, and This wing thickness gradually decreases from the leading edge 3a to the trailing edge 3b, which is a so-called "air-oil wing". As shown in Fig. 3, the wing has a predetermined "warp" in the chord direction, and its concave surface is The pressure side is 3 e and the convex side is the negative side 3 f.

The most characteristic feature of the blade 3 is that the blade 3 has a region extending along the trailing edge 3 b in the blade span direction along the trailing edge 3 b at a predetermined width (in FIG. 5 to FIG. The region near the trailing edge 3b from the line L) is defined as a specific region Q, and this specific region Q is a point that is curved toward the negative pressure surface 3f. Therefore, the blade 3 of this embodiment has In this case, the direction of the “warp” is reversed between the portion closer to the leading edge 3 a and the portion closer to the trailing edge 3 b from the area line L, and the form of the “warping” is However, like the axial blower of the first embodiment, this is a novel form completely different from the structure of the conventional blade 23 (see FIG. 19).

A mixed flow blower having an impeller 1 having the blades 3 having such a novel configuration.

In Z _2, except for the flow direction of air flow differs during air blowing, in which the same operational effects as in the axial flow fan of the first embodiment can be obtained. Therefore, here, the following description will be omitted by using the corresponding description in the first embodiment.

(Third embodiment)

8 to 10 show an outdoor unit Y of an air conditioner provided with the axial blower according to the first embodiment. In the outdoor unit Y, the inside of a rectangular casing 10 is partitioned in the left-right direction by a partition wall 11, one side of which is a heat exchange room 12 and the other side is a machine room 13 and the heat exchange room 12 The axial blower and the heat exchanger 6 are arranged in the inside, and the compressor 7 is arranged in the machine room 13. Further, a grill 8 is provided at an outlet 9 facing the axial blower.

In the outdoor unit Y, when the axial blower is operated and the impeller 1 rotates, the outdoor unit Y passes through the heat exchanger 6 and the impeller 1 from the outside and is discharged from the outlet 9 to the outside. An air flow is generated, and heat is exchanged between the air flow and the refrigerant circulating in the heat exchanger 6.

In the outdoor unit Y of this embodiment, since the axial blower according to the first embodiment is provided as air supply means to the heat exchanger 6, the axial blower Zi is highly efficient and consumes less power. The outdoor unit Y is an ideal outdoor unit that has both high heat exchange efficiency and energy saving because it has low energy consumption and excellent energy saving.

(Modified example)

In the axial flow blower Zi of the first embodiment, a thick-walled “air oil blade” as shown in FIG. 3 is employed as the blade 3, and the mixed flow blower of the second embodiment is used. Z. In FIG. 7, the blade 3 is a thin airfoil as shown in FIG. Although the oil wing J is employed, the blade 3 in the present invention is not limited to such a form. For example, various forms as shown in FIGS. 11 to 13 can be employed. is there.

The blade 3 shown in FIG. 11 is an irregularly shaped airfoil blade in which a portion near the leading edge 3a is locally thickened and other portions are thinned.

The blade 3 shown in FIG. 12 has a relatively wide portion near the leading edge 3 a and a thicker portion, and the blade thickness gradually decreases from the thick portion toward the trailing edge 3 b. Airfoil wings.

The blade 3 shown in FIG. 13 is a plate blade formed by bending a thin plate having a constant thickness with a predetermined “warpage”.

In any of these forms of the blade 3, the predetermined region on the trailing edge 3 b side (that is, the above-described specific region Q) is curved toward the negative pressure surface 3 ί, so that the first and second embodiments can be modified. in which it is possible to obtain the same effects as according blower 2 Zeta _2.

Claims

The scope of the claims

1. A fan equipped with an impeller (1) in which a plurality of blades (3, 3, ...) are radially mounted on the outer periphery of a hub (2).

Each of the blades (3) is characterized in that a specific region (Q) extending in the blade span direction with a predetermined width along the trailing edge (3b) of the blade is curved toward the suction surface (3f). Blowing

2. In the blower according to claim 1,

Above blade (3) Force A blower that is characterized by having a substantially uniform thickness from its leading edge (3a) to its trailing edge (3b).

3. In the blower according to claim 1,

A blower characterized in that the cross section of the blade (3) has a streamline shape.

4. In the blower according to claim 1,

A blower provided in an air conditioner.

5. Hot exchange! ^ (6) and an air conditioner comprising a blower (Ζ _ν Ζ ₂ ),

An air conditioner characterized by applying the blower according to claim 1, 2 or 3 as said blower (Ζ Ζ ₂ ).