JP2810196B2 - Outdoor unit for air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an outdoor unit for an air conditioner, and more particularly to an outdoor unit for an air conditioner that has low noise and is suitable for high-efficiency heat exchange.

[Conventional technology]

Conventional air conditioning outdoor units are, for example,
As described in -84373, between the top plate and the bottom plate, a plurality of heat exchangers are provided in the circumferential direction, and at a center position of the plurality of heat exchangers and in a direction orthogonal to the heat exchanger. It has been proposed to provide a fan, and a bell mouth around the fan, wherein the top plate is bent downward at right angles.

[Problems to be solved by the invention]

In the above prior art, the distance between the tip of the bell mouth and the lower end of the fan is configured to be constant along the outer circumference of the fan. On the other hand, in the outdoor unit, a movable part such as a compressor and a storage space for electrical components are required, so that only a part of the outer surface of the unit can be used as a ventilation surface of the heat exchanger.

The magnitude of the wind velocity passing through the heat exchanger differs in principle in the circumferential direction. For example, when the fan is rotated in a counterclockwise direction as viewed from the upper surface of the unit, the wind speed passing through the heat exchanger element downstream of the rotation becomes smaller than the wind speed passing through the heat exchanger element upstream of the rotation. This is because all the cooling air is sucked in from the air outlet outside the unit, passes through each heat exchanger element and is sucked into the fan, so that a suction force works in the direction almost equal to the fan rotation direction immediately before the fan inlet. .

On the upstream side, the direction of this force and the direction of suction from the unit inlet to the fan match, so the wind speed passing through the upstream heat exchanger element increases, while on the downstream side, the direction of the suction force The suction direction from the unit intake port to the fan is
On the contrary, the flow immediately after the outlet of the fan is returned to the fan suction side through the gap between the fan and the bell mouth, so that the wind speed passing through the rotating downstream heat exchanger element is reduced. .

By the way, the ventilation resistance of the heat exchanger, which is the main resistance of the fan load, is determined by the part of the heat exchanger that has the highest speed at all times. Invite. Since the noise is substantially proportional to the square of the fan load, as a result, there is a problem that the fan noise increases. Further, this non-uniformity leads to non-uniformity in the amount of heat exchange between the components of the heat exchanger, which causes a problem that the efficiency of the entire heat exchanger in the outdoor unit is reduced.

An object of the present invention is to provide an air conditioner capable of uniformly and effectively utilizing the entire surface area of a heat exchanger provided in an outdoor unit for air conditioning, and reducing fan noise by increasing heat exchange performance and reducing fan load. An object of the present invention is to provide a fan device.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a fan provided at a discharge port at an upper part of an outdoor unit, a bell mouth provided in an outer peripheral direction of the fan, and a rear mouth and a side mouth provided inside the outdoor unit. In the outdoor unit for an air conditioner having a heat exchanger, an upper portion of the heat exchanger covers an outer periphery of the bell mouth, and a tip portion of the bell mouth facing the heat exchanger in a rotation direction of the fan. The distance from the lower end of the fan gradually decreases, and the distance between the tip of the bell mouth on the anti-heat exchanger side and the lower end of the fan gradually increases.

[Action]

According to the present invention, the distance between the upper end portion and the lower end portion of the fan at the tip of the bell wind guide for the fan style is different in the outer circumferential direction of the fan. By the way, in the fan blower, a convex bell mouth is provided at the tip of the shroud forming the wind discharge port, and the heat exchanger element facing the convex portion is:
Due to the tightness of the bell mouth or the very small gap between the heat exchanger element and the bell mouth, the wind speed through this element is extremely low, resulting in the element functioning as a heat exchanger. do not do. Therefore, when the distance between the upper end of the bell mouth and the lower end of the fan is changed in the circumferential direction so as to be almost inversely proportional to the magnitude of the wind speed, the effective heat transfer area of each heat exchanger element changes according to this distance. Therefore, it is possible to equalize the wind speed passing through the heat exchanger.

Further, the distance between the upper end of the bell mouth and the upper end and the lower end of the fan is gradually reduced along the direction of rotation of the fan on the outer periphery of the fan substantially facing the heat exchanger. In the above, the configuration is such that it gradually increases along the fan rotation direction, so that the distance along the rotation direction is greater on the outer periphery of the fan almost facing the heat exchanger than when the distance is constant on the outer circumference of the fan. As a result, the effective heat exchanger area gradually increases, the wind speed passing through each element of the heat exchanger gradually decreases, and the wind speed becomes uniform. On the other hand, on the outer periphery of the fan, which is not substantially facing the heat exchanger, the effective heat exchanger area gradually decreases along the rotation direction, so that the wind speed passing through each element of the heat exchanger gradually increases, and the wind speed increases. Make uniform. That is, the wind speed passing through the heat exchanger is constant, and as a result, the fan load is reduced due to the reduction of the ventilation resistance of the heat exchanger, so that the blowing noise is reduced and the heat exchanger efficiency is improved.

In addition, since a drain hole is provided at the bottom of the arc-shaped bell mouth at the inner end of the cylindrical portion of the shroud, it is possible to prevent rainwater from accumulating at the bottom, and to freeze the rainwater or freeze the icicles. Contact with the fan and damage to the fan can be prevented.

In addition, since the tip of the bell mouth is always disposed between the lower end of the fan and the upper end of the fan in the circumferential direction, a part of the fan discharge air passes through the gap between the bell mouth and the outer periphery of the fan to the fan suction side. The amount of recirculation decreases, and the total amount of air passing through the fan contributes needlessly to the cooling of the heat exchanger and can prevent an increase in blowing noise due to disturbance on the fan suction side.

The heat exchanger is configured so that one of the heat exchangers facing the unit suction surface extends along the fan rotation direction, so that the fan rotation circumferential direction and the unit suction Since the area where the direction from the surface to the center of Juan can be reversed is narrow, the wind speed distribution in the heat exchanger is
As a result, the airflow noise is reduced by reducing the ventilation resistance of the heat exchanger, and the heat exchange efficiency is improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 is a top view showing an air conditioner installed outdoors, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line BB of FIG. FIG. 4 is a perspective view of a section taken along line BB, FIG. 5 is a perspective view of a shroud with a bell mouth,
FIG. 6 is a cross-sectional view taken along the line CC of FIG. 5, and FIG.
It is the D section enlarged view of the figure.

As shown in FIGS. 1, 2 and 3, a heat exchanger 2 is provided on one side suction part 12 of the front panel 1, and a machine room 4 and a relay board are provided below a motor mounting plate 3 on the other side. An electric component box 5 for storing the control parts and the like is provided. A motor 6 fixedly supported by the motor mounting plate 3 and a fan 7 and a shroud 9 driven to rotate by the motor 6 are provided above the motor mounting plate 3 of the panel 1. As shown in FIG. 1, the heat exchanger 2 is composed of a heat exchanger element 2b substantially parallel to the unit side suction part 12, a heat exchanger element 2a obtained by extending the heat exchanger element 2b in the direction of rotation of the fan, and the above heat exchange element. A heat exchanger element 2c is formed by extending the container element 2b in the direction opposite to the rotation of the fan, and is provided between the top plate 10 and the bottom plate 11.

As shown in FIGS. 5 and 6, the distance Δa between the upper end 16 of the shroud 9 and the bell mouth tip 14 is on the outer circumference of the fan insertion opening 17 and on the 1/2 circumference. A shroud 9 is provided on the upper surface of the unit as shown in FIGS. 1 to 4 so as to increase gradually and to decrease gradually on the other half of the circumference. Since the axis of rotation of the axial flow fan 7 is configured to be orthogonal to the unit bottom plate 11, as a result, as shown in FIG.
The distance Δ between the fan and the lower end 13 of the fan is gradually reduced along the rotation direction of the fan along the semicircle on the outer periphery of the fan facing the heat exchanger as shown in FIGS. On the other hand, on the outer circumference of the other fan, it gradually increases.

The distance Δ between the bell mouth tip 14 and the fan lower end 13 is
In a conventional outdoor unit that is constant on the outer circumference of Juan,
The wind speed distribution in the fan circumferential direction of the heat exchanger configured to surround the fan differs greatly, and particularly, as shown in FIG. 1, the passing wind speed in the heat exchanger element 2c provided on the downstream side in the fan rotation direction is reduced. Is smaller than the heat exchanger element 2a provided on the upstream side in the fan rotation direction.

By the way, as shown in FIG. 7, cooling air is sucked into the fan 7 from the unit side suction surface 12 through the heat exchanger 2. Originally, the wind speed is high near the fan suction part. Therefore, in order to improve the heat exchanger performance of the outdoor unit, it is necessary to effectively use the heat exchanger element provided near the fan, but it is equivalent to the bell mouth 8. Since the heat exchanger element 2x to be replaced is almost completely shielded by the bell mouth 8, it does not contribute to the heat exchange performance. Therefore, in the outdoor unit of the present embodiment, the distance Δ between the bell mouth tip portion 14 and the fan lower end portion 13 is changed in the circumferential direction of the fan, so that the area of the heat exchanger element 2x is equal to the distance Δ. Therefore, the distribution of the wind speed changes in inverse proportion, so that the circumferential wind speed distribution of each portion of the heat exchanger acts to be uniform. That is, in the present embodiment, for a heat exchanger element having a large wind speed, the bell mouth is moved to the upper portion so as to increase Δ, the effective heat exchanger area of this portion is increased, and the wind speed is reduced. For a small heat exchanger element, move the bell mouth to the lower side so that Δ becomes smaller,
By increasing the wind speed by reducing the effective heat exchanger area in this portion, it acts to uniform the circumferential wind speed distribution of the heat exchanger disposed so as to surround the fan. According to the present embodiment, by uniformizing the wind speed distribution for the heat exchanger, the distribution of the heat exchange amount of each part in the heat exchanger becomes uniform, the heat exchange efficiency increases, and the maximum value of the wind speed decreases. This has the effect of reducing the ventilation resistance of the heat exchanger and reducing the blowing noise as the fan load decreases.

Further, as shown in FIG. 5, the shroud 9 with the bell mouth 8 has an arc-shaped bell mouth 8 at the lower end of the cylindrical portion 15.
A drain hole 12 was formed at the bottom of the. In this embodiment,
Prevent rainwater from accumulating on the bottom, and prevent rainwater from accumulating on the bottom to freeze due to the low temperature of the outside air. Can be prevented.

FIG. 8 is a top view of an outdoor unit for an air conditioner according to another embodiment of the present invention, and FIG. 9 is a sectional view taken along the line EE of FIG. 8 and showing only the shroud. Show.
A heat exchanger 2d substantially parallel to the unit suction surface 12 and a heat exchanger 2e one of which is extended substantially along the fan rotation direction.
Since the heat exchanger 2 is configured to surround the fan, the heat exchanger element 2d on the downstream side in the fan rotation direction is substantially parallel to the unit suction surface 12, and furthermore, the fan rotation center is shifted from the unit center by the unit side plate. Because of the movement to the 17 side, the region where the fan rotation circumferential direction and the direction from the unit suction surface 12 to the fan center can be reversed for each circumferential element of the heat exchanger 2 is extremely limited. In this case, as shown in FIG. 9, the upper surface 16 of the shroud 9 and the tip
Variation with respect to the rotational direction of the distance delta _b between may be smaller than in the case of П type heat exchanger shown in Figure 1.

In this embodiment, the circumferential direction of the uniform the shape of the heat exchanger of air velocity distribution in the heat exchanger, mounted within Yunitsuto Juan position, in which was achieved by the circumferential changes of the bellmouth height delta _b.

Further, as shown in FIG. 5, the shroud with a bell mouth is formed by integral molding with a resin material, thereby achieving a reduction in the number of parts, weight reduction and cost reduction.

〔The invention's effect〕

According to the present invention, since the distance between the bell mouth tip surface and the fan lower end is changed along the circumferential direction of the fan, the wind speed distribution passing through the heat exchanger in each part of the heat exchanger in the circumferential direction is made uniform. Therefore, there is an effect that the fan load is reduced by reducing the ventilation resistance of the heat exchanger, and the blowing noise is reduced.
Furthermore, since the heat exchange performance of each part of the heat exchanger is equalized by uniformizing the wind speed distribution, there is an effect that the heat exchange efficiency is improved. In addition, the bell mouth tip is arranged between the lower end face of the fan and the upper end face of the fan in the circumferential direction, so that it is possible to suppress the perfusion of the blood flowing through the gap between the bell mouth and the fan. By changing the distance between the fan and the lower end of the fan along the circumferential direction of the fan, deterioration of the fan performance can be prevented. Furthermore, since one of the heat exchangers facing the unit suction surface is extended in the fan rotation direction, a reduction in wind speed at the heat exchanger element downstream in the fan rotation direction can be suppressed, reducing the blowing noise and improving the heat exchange performance. Can be achieved. In addition, a drain hole is provided in the arc-shaped bottom part of the lower end of the cylindrical part of the shroud to prevent rain water from accumulating, and to prevent rain water from freezing due to a decrease in the temperature of the outside air, or to contact the fan through icicles In addition, it is possible to prevent the fan from being damaged.

Furthermore, since the shroud and bell mouth are integrally molded with resin, cost reduction, reduction in the number of parts, and weight reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a top view of an outdoor unit for an air conditioner according to an embodiment of the present invention installed outdoors, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. FIG. 4 is a perspective sectional view taken along the line BB of FIG. 1 and FIG.
Fig. 6 is a perspective view of a shroud with a bell mouth, Fig. 6 is a cross-sectional view taken along the line CC of Fig. 5, Fig. 7 is an enlarged view of a portion D of Fig. 3, and Fig. 8 is another embodiment. FIG. 9 is a top view of an outdoor unit showing an example, and FIG. 9 is a sectional view taken along the line EE in FIG. 1 ... front panel, 2 ... heat exchanger, 7 ... fan, 8
... bellmouth, 9 ... shroud, 15 ... shroud cylinder, 12 ... drain hole, 16 ... top of shroud, 17 ...
... Unit side panel.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroki Terada 390 Muramatsu, Shimizu-shi, Shizuoka Pref. Inside Shimizu Plant, Hitachi Ltd. (72) Inventor Isamu Horiuchi 390 Muramatsu, Shimizu-shi Shizuoka Pref. Inside the factory (72) Inventor Takao Chiaki 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside Shimizu Plant, Hitachi Ltd. (72) Inventor Fumihiko Kitani 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside Shimizu Plant, Hitachi Ltd. (72) Invention Person Yoshihiro Takada 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (56) References Japanese Utility Model Sho 56-88065 (JP, U) Japanese Utility Model Sho 61-149064 (JP, U) Japanese Utility Model Sho 56- 81369 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24F 5/00

Claims (1)

(57) [Claims] 1. A fan provided at a discharge port at an upper part of an outdoor unit, a bell mouth provided at an outer peripheral direction of the fan, and a heat exchanger provided at a rear portion and both side portions inside the outdoor unit. In the outdoor unit for an air conditioner, the upper part of the heat exchanger covers the outer periphery of the bell mouth, and the tip part of the bell mouth and the lower end part of the fan facing the heat exchanger in the rotation direction of the fan. The distance between the tip of the bell mouth on the side of the anti-heat exchanger and the distance between the lower end of the fan is gradually increased.