JP2021162173A - Outdoor unit of air conditioner - Google Patents

Abstract

To provide an outdoor unit of an air conditioner which causes a bell-mouth to efficiently rectify wind blown from a propeller fan to improve ventilation efficiency.SOLUTION: An outdoor unit of an air conditioner includes: a propeller fan 21 having vanes 24; and a cylindrical bell-mouth. The bell-mouth has: a cylindrical duct part 35 which encloses the propeller fan 21; an expanding diameter duct part 34 which is disposed on the duct part 35 and has an inner peripheral diameter larger than an inner peripheral diameter of the duct part 35; and a step part 38 connected to an upper end of the duct part 35 and a lower end of the expanding diameter duct part 34 and extending in a radial direction. In a rotation axis direction, an uppermost end of the vane 24 and an inner surface of the step part 38 are at the same height.SELECTED DRAWING: Figure 5

Description

The present invention relates to an outdoor unit of an air conditioner.

As an outdoor unit of a conventional air conditioner, FIG. 1 of Patent Document 1 shows a propeller fan having wings attached around a hub installed on a rotating shaft, a duct portion provided so as to surround the propeller fan, and a duct portion provided so as to surround the propeller fan. The duct portion is provided with a tubular bell mouth that surrounds the propeller fan and whose end in the air blowing direction is located radially outside the outer peripheral end of the propeller fan, and the end of the bell mouth in the air blowing direction. With a flat surface portion extending outward in the radial direction of the propeller fan and a tubular mouth ring extending in the air blowing direction from the radial outer end portion of the flat surface portion. An outdoor unit of an air conditioner is shown in which a vortex fixing chamber is formed by a flat surface portion and a mouth ring to improve the ventilation performance of a propeller fan.
In the outdoor unit shown in Patent Document 1, since the position of the uppermost end portion of the propeller fan blade is higher than the position of the flat surface portion, a part of the blade protrudes toward the mouse ring side.

Japanese Unexamined Patent Publication No. 2008-89271

The wind blown from the propeller fan blows out while spreading in the radial direction, but as in the prior art shown in Patent Document 1, if the position of the uppermost end of the wing is higher than the position of the flat surface, the propeller Since all the wind blown from the fan is blown out without being rectified by the mouse ring, there is a problem that the improvement of the blowing efficiency is suppressed.
In view of the above problems, an object of the present invention is to provide an outdoor unit of an air conditioner that efficiently rectifies the wind blown from a propeller fan by a bell mouth to improve the blowing efficiency.

One aspect of the present invention includes a propeller fan having a rotation axis and a plurality of wings, and a cylindrical bell mouth having an air outlet at an upper portion and a suction port at a lower portion, wherein the bell mouth is the propeller fan. A cylindrical duct portion surrounding the duct portion, an enlarged duct portion arranged above the duct portion and having an inner peripheral diameter larger than the inner peripheral diameter of the duct portion, and an upper end of the duct portion and the enlarged duct portion. An air conditioner having a step portion connected to a lower end and extending in the radial direction, and having the same height as the uppermost end of the blade and the inner surface of the step portion in the direction of the rotation axis. It is an outdoor unit.

According to the present invention, since the height of the uppermost end of the wing and the inner surface of the step portion are the same in the direction of the rotation axis, the entire wing is completely surrounded by the bell mouth, so that the propeller fan can be used. The blowing air can be efficiently rectified by the bell mouth to improve the blowing efficiency.

It is a vertical view of the outdoor unit of the air conditioner which concerns on this invention. It is a top view of the outdoor unit of the air conditioner which concerns on this invention. It is a perspective view of the bell mouth of the air conditioner which concerns on this invention. It is sectional drawing of the bell mouth and the blower of the air conditioner which concerns on this invention. It is the schematic of the enlarged cross section of part A of FIG. It is the schematic of the enlarged cross section of part B of FIG. It is a figure which shows the relationship between the axial distance between the lower end of a bell mouth and the lower end of a propeller fan, and the air volume ratio. It is a figure which shows the relationship between the axial distance between the lower end of a bell mouth and the lower end of a propeller fan, and the input ratio.

Hereinafter, examples of the outdoor unit of the air conditioner according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

FIG. 1 is a vertical sectional view showing an embodiment of the outdoor unit 1 of the air conditioner according to the present invention, and FIG. 2 is a plan view showing an embodiment of the outdoor unit 1 of the air conditioner according to the present invention. .. The outdoor unit 1 is connected to an indoor unit (not shown) by a pipe to form a part of a refrigerating circuit in which a refrigerant circulates. It is equipped with an oil separator, a four-way valve, and an outdoor unit expansion valve.

The outdoor unit 1 includes a cylindrical bell mouth 3 having an air outlet 33 at the upper part and a suction port 36 at the lower part, and a machine room 5 arranged below the bell mouth 3 and having an open upper part. A blower 2 is arranged inside the bell mouth 3, and a compressor 6, an outdoor heat exchanger 7, an electrical box 8, and the like are arranged inside the machine room 5. In this embodiment, two outdoor units 1 are provided, but the number of outdoor units 1 may be one. Since the two outdoor units 1 have the same structure, one of the outdoor units 1 will be described below.
The machine room 5 has a box shape including a front plate 51, side plates 52 on both sides, a back plate 53, and a bottom plate 54, and the front plate 51 and the side plate 52 on the side facing the outside have suction ports (not shown). The compressor 6 and the electrical box 8 are provided and arranged on the bottom plate 54.

The outdoor heat exchanger 7 is composed of two heat exchangers arranged to face suction ports provided on each of the front plate 51 and the side plate 52 on the side facing the outside, and two heat exchanges. The vessels are integrally connected by pipes that form part of the refrigeration circuit. The blower 2 is composed of a propeller fan 21 and a motor 22. The propeller fan 21 is attached to the rotating shaft of the motor 22. A motor pedestal 9 for mounting the blower 2 is arranged in the upper part of the machine room 5, the motor 22 is attached to the motor pedestal 9 by a bolt (not shown), and the blower 2 protrudes from the upper surface of the machine room 5. , The propeller fan 21 is arranged so as to be surrounded by the bell mouth 3.
The outdoor unit 1 rotates the propeller fan 21 by driving the motor 22, sucks air into the machine room 5 from the suction port of the machine room 5, and the sucked air passes through the outdoor heat exchanger 7. As a result, heat is exchanged with the refrigerant, and the heat-exchanged air is blown out from the air outlet 33 formed in the upper part of the bell mouth 3.

FIG. 4 is a vertical cross-sectional view of the bell mouth 3 and the blower 2. The bell mouth 3 has an elliptical tubular diameter-expanding duct portion 34 having an outlet 33 at the upper portion and directing the blown air upward, and a cylindrical duct portion 35 arranged below the diameter-expanding duct portion 34. It is composed of a suction duct portion 37 arranged below the duct portion 35 and having a suction port 36 at the lower portion, and a step portion 38 connecting the diameter-expanded duct portion 34 and the duct portion 35. The lower part of the suction duct portion 37 is provided with a bell mouth pedestal portion 39 attached to the machine room 5. Vertical ribs 40 for reinforcing the diameter-expanded duct portion 34 and the duct portion 35 are spaced in the circumferential direction between the outer peripheral surfaces of the diameter-expanded duct portion 34 and the duct portion 35 and the upper surface of the bell mouth pedestal portion 39. On the outer peripheral surfaces of the enlarged-diameter duct portion 34 and the duct portion 35, peripheral ribs 41 for reinforcing the enlarged-diameter duct portion 34 and the duct portion 35 are similarly spaced in the height direction. Have been placed.

The duct portion 35 is a portion surrounding the propeller fan 21, and the inner peripheral surface has a circular cross section in the direction orthogonal to the rotation axis of the propeller fan 21. The inner peripheral surface of the enlarged duct portion 34 has an elliptical cross section in the direction orthogonal to the rotation axis of the propeller fan 21, the minor diameter is the same as the diameter of the inner peripheral surface of the duct portion 35, and the major diameter is the duct. It is longer than the diameter of the inner peripheral surface of the portion 35. The stepped portion 38 connecting the enlarged diameter duct portion 34 and the duct portion 35 is provided on the long diameter side so as to face each other, and is not provided on the short diameter side.

FIG. 5 is a diagram schematically showing a part A of FIG. On the inner surface side of the step portion 38 connected to the diameter-expanding duct portion 34 and the duct portion 35, from the upper end of the inner peripheral surface of the duct portion 35 to the lower end of the inner peripheral surface of the diameter-expanding duct portion 34 toward the outer side in the radial direction. It has an extending flat surface portion 42. The angle at which the flat surface portion 42 and the inner peripheral surface of the duct portion 35 intersect and the angle at which the flat surface portion 42 and the inner peripheral surface of the enlarged diameter duct portion 34 intersect are 90 °, respectively. That is, the flat surface portion 42 of the step portion 38 is parallel to the direction orthogonal to the rotation axis and is not inclined with respect to the rotation axis.

As shown in FIG. 2, the flat surface portion 42 has a pair of crescent shapes when viewed from above, and is arranged so that both ends of the crescent shape are connected to each other and the concave sides face each other. Therefore, since the flat surface portion 42 does not exist in the portion where both ends of the crescent shape are connected to each other, there is no step on the inner peripheral surface of the diameter-expanded duct portion 34 and the inner peripheral surface of the duct portion 35 in a straight line in the vertical cross section. It becomes.

FIG. 6 is a diagram schematically showing a portion B of FIG. The suction duct portion 37 located on the lower side of the duct portion 35 is connected to the lower end of the duct portion 35 and increases in diameter as the inner peripheral diameter goes downward, and a rectangle connecting to the lower end of the bell portion 43. It is provided with a bell mouth pedestal portion 39 having a shape. The inner circumference of the bell portion 43 has an arcuate cross section in the axial direction and a circular cross section in the direction orthogonal to the rotation axis. The bell mouth pedestal portion 39 includes an upper surface portion 44 having a rectangular upper surface and an outer edge portion 45 that bends downward from the outer edge of the upper surface portion 44, and the outer edge portion 45 is fixed to the upper portion of the machine room 5. The inner peripheral side of the bell mouth pedestal portion 39 constitutes the suction port 36 of the bell mouth 3.

As shown in FIG. 2, the propeller fan 21 has four wings 24 mounted around a columnar hub 23. The shape of the hub 2 is not limited to a columnar shape, and may be any shape such as a triangular columnar shape or a conical shape. The arrow shown in FIG. 2 indicates the direction of rotation of the propeller fan. The wing 24 has an outer side 27 located on the outer side in the radial direction so as to connect the front side 25 located on the front side in the rotation direction, the rear side 26 located on the rear side in the rotation direction, and the front side 25 and the rear side 26. It is formed by a three-dimensional curved surface surrounded by an inner side fixed to the hub 23. The front side 25 is formed by a concave curve that goes toward the front in the rotation direction toward the outside in the radial direction, and the rear side 26 is a gentle convex curve that goes toward the front in the rotation direction toward the outside in the radial direction. Is formed of. A slight clearance is provided between the outer side 27 and the inner peripheral surface of the duct portion 35 so that the outer side 27 does not come into contact with the inner peripheral surface of the duct portion 35.

In the direction of the rotation axis, the rear side 26 is arranged above the front side 25, and is gently inclined from the rear side 26 toward the front side 25. The lower front end 28, which is the end of the front side 25 on the outer side 27 side, is lower than the front hub connecting portion 29 whose front side 25 connects to the hub 23, and is the end of the rear side 26 on the outer side 27 side. The upper rear end 30 is lower than the rear hub connecting portion 31 that connects to the hub 23. In the propeller fan 21, the rear hub connecting portion 31 is the highest uppermost end and the lower front end 28 is the lowest lowest end end in the direction of the rotation axis. The rotation axis overlaps the rotation axis of the propeller fan 21 and the rotation axis of the motor 22.

Next, the positional relationship between the bell mouth 3 and the propeller fan 21 in the rotation axis direction will be described with reference to FIGS. 5 and 6. As shown in FIG. 5, at the height in the direction of the rotation axis, the rear hub connection portion 31 of the propeller fan 21 and the flat surface portion 42 of the step portion 38 provided on the bell mouth 3 are at the same height position. In this embodiment, since the rear hub connecting portion 31 is the propeller fan 21 at the highest position, the rear hub connecting portion 31 has the same height as the flat surface portion 42. For example, the upper rear end 30 In the case of the propeller fan 21 formed so that is at the highest position, the upper rear end 30 may be at the same height as the flat surface portion 42. That is, the entire propeller fan 21 may be housed in the duct portion 35 in the direction of the rotation axis when viewed from a direction orthogonal to the rotation axis.

By making the rear hub connecting portion 31 at the same height as the flat surface portion 42, the diameter-expanding duct portion 34 is arranged above the rear hub connecting portion 31 at the highest position of the propeller fan 21. The flow of air blown out from the propeller fan 21 that spreads in the radial direction can be maintained without being resisted by the diameter-expanding duct portion 34, and noise can be reduced. Further, since the flat surface portion 42 of the step portion 38 is parallel to the direction orthogonal to the rotation axis and is not inclined with respect to the rotation axis, the step portion 38 functions as a rib, and the strength of the bell mouth 3 is increased. Can be kept.

Next, the relationship between the height h of the blade 24 and the height H of the diameter-expanding duct portion 34 in the axial direction, and the relationship between the radial width L of the flat surface portion 42 and the height H of the diameter-expanding duct portion 34. explain. The height h of the wing 24 is the axial length from the lower front end 28 of the wing 24 to the rear hub connecting portion 31, that is, the total length in the axial direction of the wing 24, and is the highest from the lowermost end of the wing 24. It is the length to the end. The height H of the diameter-expanding duct portion 34 is the length from the flat surface portion 42 to the upper end of the diameter-expanding duct portion 34 in the axial direction. The radial width L of the flat surface portion 42 is the width in the major axis because the diameter-expanding duct portion 34 has an elliptical shape. The value (H / h) obtained by dividing the height H of the diameter-expanding duct portion 34 by the blade height h is preferably 0.2 ≦ H / h ≦ 0.5. Further, it is desirable that the value (L / H) obtained by dividing the radial width L of the flat surface portion 42 by the height H of the diameter-expanding duct portion 34 is 0 <L / H ≦ 0.4. The minimum value of the height H of the diameter-expanding duct portion 34 is the height required to guide the flow of air blown out from the propeller fan 21 that flows upward while spreading in the radial direction so as not to spread too much in the radial direction. be. The maximum value of the height H of the diameter-expanding duct portion 34 is to minimize the resistance because resistance is generated when the air flow blown from the propeller fan 21 flows along the inner circumference of the diameter-expansion duct portion 34. The height to do.

In this embodiment, the inner peripheral surface of the diameter-expanding duct portion 34 has an elliptical cross section, but it does not necessarily have to be elliptical and may be circular. However, if there are restrictions on the installation location of the outdoor unit 1 and the diameter of the diameter-expanding duct portion 34 cannot be increased, noise can be reduced even in a limited installation location by making it oval. effective.
Next, with reference to FIG. 6, the positional relationship between the lower front end 28 of the propeller fan 21 and the lower end 46 of the duct portion 35 of the bell mouth 3 in the axial direction will be described. As shown in FIG. 6, the lower end 46 of the cylindrical duct portion 35 is connected to the upper end of the bell portion 43 whose diameter is expanded in a curved shape of the suction duct portion 37, and is the maximum of the portion where the inner peripheral diameter is not expanded. It is a lower point. As shown in FIG. 6, the lower front end 28 of the propeller fan 21 is arranged at the same height as the lower end 46 of the duct portion 35 in the axial height.

Relationship between the position of the lower front end 28 of the propeller fan 21 and the lower end 46 of the duct portion 35 and the air volume ratio, and the relationship between the position of the lower front end 28 of the propeller fan 21 and the lower end 46 of the duct portion 35 and the input ratio. , The results obtained by the experiment will be described with reference to FIGS. 7 and 8. The air volume ratio in FIG. 7 is a value showing the difference in air volume when the same motor output is used, and the higher the value, the higher the capacity. The input ratio in FIG. 8 is a value indicating the difference in motor output required to produce the same air volume as a ratio, and the lower the value, the higher the capacity. The horizontal axis in FIGS. 7 and 8 represents the distance X (mm) between the lower front end 28 of the propeller fan and the lower end 46 of the duct portion 35, and the distance X is 0 (mm) with the lower front end 28 of the propeller fan 21. The lower end 46 of the duct portion 35 has the same height, and a minus (-) distance X means that the lower front end 28 of the propeller fan 21 is higher than the lower end 46 of the duct portion 35, and the distance X is higher. The plus (+) means that the lower front end 28 of the propeller fan 21 is lower than the lower end 46 of the duct portion 35. The numerical value of 100% on the vertical axis of FIGS. 7 and 8 indicates the air volume ratio and the input ratio when the lower front end 28 of the propeller fan 21 is 99 (mm) lower than the lower end 46 of the duct portion 35 as a conventional technique. Shown.

As is clear from FIGS. 7 and 8, when the lower front end 28 of the propeller fan 21 and the lower end 46 of the duct portion 35 are at the same height (X = 0), the capacity in the input ratio and the air volume ratio is the highest. was gotten. When -20 (mm) ≤ X ≤ +20 (mm), the input ratio is expected to be about 94.0% or less, and the air volume ratio is expected to be about 104.0% or more, so the capacity is high, and X <-20 (mm). And, when 20 (mm) <X, the results were obtained that the capacity at the input ratio and the air volume ratio became low.

Next, the relationship between the radius of curvature R of the bell portion 43 whose inner peripheral diameter increases from the lower end of the duct portion 35 to the bell mouth pedestal portion 39 and the noise will be described. When R was 50 (mm) or less, the noise value was 60.8 dB, whereas when R was larger than 50 (mm), the noise value was 62.3 dB. Therefore, it was obtained that the radius of curvature R of the bell portion 43 is preferably 50 (mm) or less.
Although the above description has been made with reference to a limited number of embodiments, the scope of rights is not limited thereto, and modifications of the embodiments based on the above disclosure are obvious to those skilled in the art.

1 ... outdoor unit, 2 ... blower, 3 ... bell mouth, 5 ... machine room, 9 ... motor pedestal, 21 ... propeller fan, 23 ... hub, 24 ... wings, 25 ... front side, 26 ... rear side, 27 ... Outer side, 28 ... lower front end, 29 ... front hub connection, 30 ... upper rear end, 31 ... rear hub connection, 33 ... outlet, 34 ... enlarged duct, 35 ... duct, 36 ... suction port , 37 ... Suction duct part, 38 ... Step part, 39 ... Bellmouth pedestal part, 42 ... Flat part, 43 ... Bell part, 44 ... Top surface part, 45 ... Outer edge part, 46 ... Lower end of duct part, 51 ... Front plate , 52 ... Side plate, 53 ... Back plate, 54 ... Bottom plate, 55 ... Suction port

Claims (5)

A propeller fan with a rotating shaft and multiple wings,
A cylindrical bell mouth with an air outlet at the top and a suction port at the bottom.
The bell mouth has a cylindrical duct portion that surrounds the propeller fan, a diameter-expanded duct portion that is arranged above the duct portion and has an inner diameter larger than the inner diameter of the duct portion, and an upper end of the duct portion and the expansion. It has a stepped portion that is connected to the lower end of the diameter duct portion and extends in the radial direction.
An outdoor unit of an air conditioner, characterized in that the heights of the uppermost end of the blade and the inner surface of the step portion are the same in the direction of the rotation axis. The outdoor unit of the air conditioner according to claim 1, wherein the inner surface is parallel to the direction orthogonal to the rotation axis. Claim 1 or 2 is characterized in that the cross section of the inner circumference of the duct portion in a direction orthogonal to the rotation axis is circular, and the cross section of the inner circumference of the enlarged duct portion in a direction orthogonal to the rotation axis is elliptical. The outdoor unit of the air conditioner described in. The ratio of the total length h of the blade to the height H of the diameter-expanding duct portion in the axial direction of the rotation axis, H / h, is
The outdoor unit of the air conditioner according to any one of claims 1 to 3, wherein the range is 0.2 ≦ H / h ≦ 0.5. The ratio of the height H of the diameter-expanding duct portion in the axial direction of the rotation axis to the width L of the inner surface of the step portion in the direction orthogonal to the rotation axis, L / H, is.
The outdoor unit of the air conditioner according to any one of claims 1 to 4, wherein the range is 0 <L / H ≦ 0.4.

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