JPH1182394A - Propeller fan device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the aerodynamic performance and to reduce aerodynamic noises even when a housing is compact and has the strict constraint on size, in a propeller fan device used in an air conditioner or the like. SOLUTION: A mouth ring of this propeller fan device can be coped with the constraint on size of a propeller fan device housing, by mounting a vortex holding pocket 106 formed by an inner peripheral cylindrical face 204 opposite to an outer periphery in a radius direction of a propeller fan 105, a vortex holding bottom face 203 formed by sharply enlarging a point in a discharge direction of the inner peripheral cylindrical face 204 in a radius direction, and locating the same near a point in a discharge direction of a blade of the propeller fan 105, and a vortex holding side face 202 continued from an external part of the vortex holding bottom face 203 in an axial direction, all around the propeller fan, or by mounting one or two pieces of vortex holding pockets 106 opposite to each other at 180 deg. in a peripheral direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propeller fan device, and more particularly, to an improvement in a mouth ring shape capable of improving aerodynamic performance and reducing aerodynamic noise while coping with a restriction on a housing size.

[0002]

2. Description of the Related Art In a propeller fan device used for an air conditioner, a ventilation fan, or the like, the peripheral speed of the fan must be increased as the flow rate and pressure requirements for the fan become stricter. The sound accompanying the flow becomes strong, which causes a problem as noise. For example, a low-velocity region called the wake is formed downstream of the fan blades, but strong turbulence is generated by the shear layer generated between the wake region and the surrounding high-speed region, and the turbulence propagates upstream, and the turbulence propagates upstream. Creates pressure fluctuations on the surface. Also, when the tip vortex that develops at the outer edge of the wing separates from the wing tip, strong turbulence occurs in the separated vortex,
Strong pressure fluctuations are induced on the wing surface. When pressure fluctuations are induced on the wing surface in this way, they are radiated far away as sound waves, and become so-called aerodynamic sounds.

[0003] In addition to the aerodynamic noise radiated from the fan itself, aerodynamic noise is also generated by strong turbulence caused by the air discharged from the fan hitting a protective fan guard located immediately downstream of the fan. I do. The aerodynamic noise from the fan guard has a non-negligible intensity as the flow rate of the fan increases, and in some cases may be stronger than the aerodynamic noise of the fan itself.

[0004] In recent years, the aerodynamic performance of fans has been improved while keeping these aerodynamic noises low under social backgrounds such as an increasing need for a more comfortable living environment and an increasing interest in environmental issues. Ensuring the necessary flow rate and pressure is an important industrial issue.

Conventionally, to reduce these aerodynamic noises,
Solutions such as improving the shape of the fan itself to reduce turbulence, increasing the flow area downstream of the fan, and reducing the flow velocity hitting the fan guard to reduce turbulence have been mainly adopted. However, there has been known an example in which a similar effect is aimed at by improving a mouse ring used in combination with a fan.

For example, according to JP-A-3-179198,
A relatively long inner peripheral cylindrical surface is provided on the mouth ring facing the outer periphery of the propeller fan in the radial direction, and a vortex fixing vertical surface that rapidly expands in the radial direction from the tip in the discharge direction and a vortex fixing horizontal surface in the axial direction from the outside Is formed to create a space called a vortex anchoring chamber that covers the entire circumference of the mouth ring. Since the inner peripheral cylindrical surface is relatively long in the axial direction, the pressure sealing effect is large, and a high fan pressure can be obtained even if the pressure difference between the suction side and the discharge side becomes large. Further, the tip vortex that grows from the fan tip is attracted to the vortex fixing chamber, and the effective outer diameter of the fan increases, so that the aerodynamic performance of the fan improves. Further, at this time, the wing tip vortex circulates in a wide space, so that interference with the wing tip is small and aerodynamic noise can be reduced. In addition, since the effective flow path cross-sectional area on the fan discharge side increases, the discharge flow velocity from the fan decreases, and the aerodynamic noise from the fan guard can also be reduced.

[0007]

The technique disclosed in Japanese Patent Application Laid-Open No. 3-179198 has the above-mentioned advantages. However, since the vortex fixing chamber is formed over the entire circumference of the mouth ring, it is inevitable. The effective diameter of the mouth ring must be increased. Therefore, this method can be used only for enclosures with sufficient dimensions for the propeller fan diameter, and today's producers who want to reduce the size of the air conditioner enclosure and reduce costs. Are incompatible with the requirements of That is, this method is not necessarily effective when the propeller fan is incorporated in a housing made with a small size for cost reduction or the like.

An object of the present invention is to improve aerodynamic performance even when the air conditioner housing has dimensional restrictions and it is impossible to attach a mouth ring having a vortex fixing chamber described in the above publication. Another object of the present invention is to provide a propeller fan device including a propeller fan and a mouth ring which can reduce aerodynamic noise.

[0009]

Means for Solving the Problems To achieve the above object, a propeller fan device according to the present invention has a structural feature as described in each of claims 1 to 4. A propeller fan device according to claim 1 as an independent claim, comprising: a housing; a plurality of bladed propeller fans disposed on a discharge end face side of the upper portion of the housing; and an inner periphery opposed to a radial outer periphery of the propeller fan. The tip in the discharge direction of the cylindrical surface and the inner peripheral cylindrical surface rapidly expands in the radial direction,
Mouth ring having a vortex holding pocket formed by a vortex holding bottom surface located near the tip of the propeller fan blade in the discharge direction and a vortex holding side surface continuously and axially directed from the outside of the vortex holding bottom surface Wherein the vortex holding pocket of the mouth ring has an effective flow path cross-sectional area equivalent to the case where the vortex holding pocket is provided on the entire circumference of the mouth ring. It is characterized in that it is provided only in a part in the circumferential direction so as to be able to cope with the restriction on the size of the housing.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a propeller fan device according to a first embodiment of the present invention. Inside the air conditioner outdoor unit 103, a propeller fan 105, and a mouse ring 10 surrounding it
7 is placed. This outdoor unit has a front panel 10
It is shorter in the direction of 1 and the heat exchanger 104 and longer in the direction between the side panels 102. Since the diameter of the propeller fan 105 is large compared to the housing dimensions, two vortex holding pockets 106 are formed at two opposing positions in the circumferential direction of the mouth ring in the direction of the side panel. No vortex holding pockets were made in the direction of the exchange. The vortex holding pocket is provided with a drain hole 108. The propeller fan and the entire mouth ring are covered by a fan guard 109.

FIG. 2 shows an AA cross section of the mouth ring of FIG. 1 provided with a vortex holding pocket. The inner cylindrical surface 20 of the mouth ring surrounding the propeller fan 105
4 is provided all around. A convex curved surface 205 is provided in the suction direction of the inner peripheral cylindrical surface 204 to assist in smooth suction of the flow. A vortex holding pocket 203 is formed by a vortex holding bottom surface 203 which rapidly expands in the radial direction from the tip of the inner peripheral cylindrical surface 204 in the discharge direction, and a vortex holding side surface 202 which continuously extends from the outside of the vortex holding bottom surface 203 in the axial direction. Is formed. The diameter D4 of the discharge end face 201 located at the tip of the vortex holding side face 202 is considerably larger than the cylindrical face diameter D3, and the tip of the outer circumference discharge side of the blade of the propeller fan is located near the position of the vortex holding bottom face 203.

In the configuration of this portion, as in the example described in the above-mentioned publication, the inner peripheral cylindrical surface 204 is long in the axial direction, so that the pressure sealing effect is large and even if the pressure difference between the suction side and the discharge side becomes large. High fan pressure is obtained. Further, the tip vortex 207 generated at the fan tip is attracted to the vortex holding pocket 106, grows large, and becomes a vortex 208 that slowly circulates away from the fan tip. At this time, the aerodynamic performance of the fan improves because the effective outer diameter of the fan increases. Also, the wing tip vortex 208 slowly circulates in a wide space,
There is little interference with the wing tip and aerodynamic noise can be reduced. Moreover,
Since the effective flow path cross-sectional area on the fan discharge side increases, the discharge flow velocity decreases, and the aerodynamic noise from the fan guard 109 can also be reduced. In addition, since a hole 108 for draining water is provided on the vortex holding bottom surface 203, it is possible to prevent rainwater from accumulating, and the rainwater freezes or becomes icy and contacts the fan,
Damage to the fan can be prevented.

FIG. 3 shows a BB cross section of the mouth ring of FIG. 1 without a vortex holding pocket. The difference from the AA cross section in FIG. 2 is that the vortex holding bottom surface 203 is absent or very narrow. Therefore, if attention is paid only to this portion, the vortex holding pocket as shown in FIG. 2 cannot be formed, and the effect in terms of aerodynamic performance and aerodynamic noise realized by providing the vortex holding pocket. Can not get. That is, in the configuration shown in the example of FIG. 1, two vortex holding pockets are provided partially facing the mouth ring at 180 ° in the circumferential direction. In comparison, it is considered that aerodynamic performance and aerodynamic noise are inferior.

However, considering the case where the discharge cross-sectional areas are made equal, the non-uniformity in the circumferential direction of the wing tip vortex when flowing out of the discharge end face is rapidly reduced while flowing over a short distance. Since the same effect as when the vortex holding pocket is provided on the entire circumference can be obtained, the same effect can be obtained on aerodynamic performance and aerodynamic noise. According to the knowledge of the present inventors, even if the vortex holding pocket is provided in a part in the circumferential direction, the function sufficiently satisfies the function as long as the cross-sectional area of the flow path is equivalent to the case where it is provided on the entire circumference of the mouth ring. As a result, the present embodiment can be a sufficient alternative to improving aerodynamic performance and reducing aerodynamic noise when the size of the housing is limited.

FIG. 4 shows a further improvement obtained by modifying the mouth ring shown in the example of FIG. A propeller fan 105 and a mouth ring 107 surrounding the propeller fan 105 are placed in an outdoor unit 103 of the air conditioner. The housing of this outdoor unit is shorter in the direction of the front panel 101 and the heat exchanger 104,
The direction between the side panels 102 is longer. Propeller fan
Since the diameter of the 105 is larger than the housing size, the vortex holding pocket 106
Are formed at two opposing positions, and no vortex holding pockets are made in the direction of the front panel and the heat exchanger where there is no room for the dimensions. Spread it gradually in the direction that the fan rotates. A hole 108 for draining water is provided on the vortex holding bottom surface. The entire fan and mouth ring are covered by a fan guard 109.

By gradually widening the width of the vortex holding bottom surface in the direction in which the fan rotates, the swirling flow from the fan blade tip gradually widens in the radial direction of the mouth ring, so that the pressure loss due to the rapid expansion of the flow path is reduced. . In addition, since the occurrence of turbulence that occurs when the vehicle suddenly expands is suppressed, there is a further effect on reducing aerodynamic noise.

FIG. 5 shows an implementation example of a mouth ring in which a vortex holding pocket 106 is provided at only one location when a strong restriction is imposed on the housing size. In this example, the casing 103 of the air conditioner is long in the direction of the heat exchanger 104 and the front panel 101 and short in the direction of the side panel 102. Moreover, there is no margin in the length even in the longitudinal direction, and the vortex holding pocket 106 is provided only at one place. Even in this case, if the discharge cross-sectional area is sufficiently large, it is possible to achieve an improvement in aerodynamic performance and a reduction in aerodynamic noise equivalent to the case where the vortex holding pockets are provided all around.

FIG. 6 is an example of a mechanical device using the propeller fan device of the present invention, and is a sectional view of the outdoor unit of the air conditioner shown in FIG. 1 as viewed from the side panel 102 side. A top plate 601, a bottom plate 602, a front panel 101, and a heat exchanger 104 shown in FIG.
A propeller fan 105 is placed inside a housing formed by the outside panel 102 and both side panels 102, surrounded by a mouth ring 107, and a rotating shaft thereof is connected to a fan driving motor 606. It is supported inside the housing by the holder 605. Mechanical equipment such as compressors is in machine room 60
4 and the electrical components are housed inside an electrical box 603. The propeller fan 105 is driven by a motor 606, draws in outside air from the outside of the outdoor unit through the heat exchanger 104 and performs heat exchange, and the air passing through the fan is again discharged to the outside of the outdoor unit. The aerodynamic noise of the propeller fan is 180 ° in the circumferential direction of the mouth ring 607 described earlier.
Since the number of the vortex holding pockets 106 is reduced, the operation of the outdoor unit with lower noise can be performed.

[0020]

According to the present invention, in a propeller fan used in combination with a mouth ring, even if the dimensional restriction of the housing is strong, the fan is provided by partially providing a vortex holding pocket in the circumferential direction. The wing tip vortex spreads in the outer peripheral direction to improve aerodynamic performance. Further, according to the present invention, interference between the wing tip vortex and the wing tip can be reduced, so that aerodynamic noise can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a propeller fan device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in the vicinity of a fan blade tip in FIG. 1;

FIG. 3 is a sectional view taken along the line BB in the vicinity of a fan blade tip in FIG. 1;

FIG. 4 is a plan view of a propeller fan device according to a second embodiment of the present invention.

FIG. 5 is a plan view of a propeller fan device according to a third embodiment of the present invention.

FIG. 6 is a schematic view of a mechanical device using the propeller fan device according to the first embodiment of the present invention.

[Explanation of symbols]

 101 ... front panel 102 ... side panel 103 ... air conditioner outdoor unit housing 104 ... heat exchanger 105 ... propeller fan 107 ... mouth ring 108 ... water drain hole 109 ... fan guard 201 ... discharge end face 202 ... vortex holding side 203… vortex holding bottom 204… inner cylindrical surface 205… convex curved surface 207… wing tip vortex 208… detached circulation vortex 601… top plate 602… bottom plate 603… electric box 604… machine room 605… motor holder 606… motor

Continued on the front page (72) Katsuo Oki 502, Kandachicho, Tsuchiura-shi, Ibaraki Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Ryoji Sato 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Air Conditioning Systems Division, Hitachi, Ltd. (72) Inventor Kenichi Nakamura 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside the Air Conditioning Systems Division, Hitachi, Ltd. (72) Inventor Tetsushi Kishitani 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside the Air Conditioning Systems Division, Hitachi, Ltd. Shinichi Ide 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Kazuhiro Dobashi 390 Muramatsu, Shimizu-shi, Shizuoka Pref.HVAC, Hitachi, Ltd.

Claims (4)

[Claims] 1. A housing, a plurality of bladed propeller fans disposed on a discharge end face side of an upper portion of the housing, an inner peripheral cylindrical surface facing a radially outer periphery of the propeller fan, and discharge of the inner peripheral cylindrical surface. The vortex holding bottom face and the vortex holding side face that are axially continuous from the outside of the vortex holding bottom face are arranged so that the directional tip rapidly expands in the radial direction and is positioned near the tip of the propeller fan blade in the discharge direction. And a mouth ring having a vortex holding pocket formed by the following method. The vortex holding pocket of the mouth ring is provided with an effective flow path equivalent to the case where the vortex holding pocket is provided all around the mouth ring. A propeller fan device having a sectional area provided only in a part of a circumferential direction of the mouth ring so as to be able to cope with the restriction of the housing dimensions. 2. The vortex holding pocket is provided at a position where the vortex holding pocket suddenly expands in a radial direction from an inner peripheral cylindrical surface of the mouth ring.
2. The propeller fan device according to claim 1, wherein the amount by which the vortex holding bottom surface rapidly expands gradually increases in a direction in which the propeller fan rotates. 3. 3. The propeller fan device according to claim 1, wherein one or two of the vortex holding pockets are provided in the circumferential direction of the mouth ring so as to be opposed to each other by 180 °. 4. The vortex holding bottom surface of the vortex holding pocket is provided with a hole for draining water.
A propeller fan device according to any one of the above.