WO2017085889A1

WO2017085889A1 - Centrifugal fan, air conditioner, and refrigerating cycle device

Info

Publication number: WO2017085889A1
Application number: PCT/JP2015/082791
Authority: WO
Inventors: 惇司河野; 池田　尚史
Original assignee: 三菱電機株式会社
Priority date: 2015-11-20
Filing date: 2015-11-20
Publication date: 2017-05-26
Also published as: JP6430032B2; JPWO2017085889A1

Abstract

A centrifugal fan that operates with little noise at high efficiency is provided. The centrifugal fan is provided with a main panel, a side panel, and a plurality of blades. The side panel, which is provided so as to face the main panel, has the shape of a ring. The plurality of blades are provided between the main panel and the side panel. In the inner peripheral side of the plurality of blades, the plurality of blades have a blade inlet angle of θ1-θ3. Each of the plurality of blades has a first section, a second section, and a third section. The first section is connected to the main panel. The third section is connected to the side panel. The second section is positioned between the first section and the third section. The blade inlet angle θ1 in the first section of at least one of the plurality of blades is greater than the blade inlet angle θ2 in the second section of said at least one blade. The blade inlet angle θ3 in the third section of said at least one blade is less than the blade inlet angle θ2 in the second section of said at least one blade.

Description

Centrifugal fan, air conditioner and refrigeration cycle apparatus

The present invention relates to a centrifugal fan, an air conditioner including the centrifugal fan, and a refrigeration cycle apparatus.

JP-A-6-299994 (Patent Document 1) discloses a multiblade centrifugal fan. The centrifugal fan disclosed in Patent Document 1 has a configuration in which the entrance angles on the main plate side and the side plate side of the blades are different from each other.

JP-A-6-299994

In a centrifugal fan, the wider the blade width in the direction of the rotation axis, the more likely to be a non-uniform wind speed distribution in the blade width direction. In this case, the angle of attack at the leading edge of the blade becomes non-uniform, and the airflow is easily separated on the blade surface on the counter-rotating direction side. Such separation of the air current leads to a reduction in the effective air path width between the blades. For this reason, the separation of the air current has caused problems such as a decrease in the efficiency of the centrifugal fan and an increase in noise due to the generation of vortices.

In Patent Document 1, in the axial direction from the side plate to the main plate, a portion of 30% to 40% of the total blade width is used as a boundary, and the inlet portion of the blade is divided from the boundary into the side plate side and the main plate side. The blades are configured to have different entrance angles on the side plate side and the main plate side. In patent document 1, the vortex and vortex sound which generate | occur | produce at the entrance part of a wing | blade are reduced by such a structure.

However, in the conventional sending fan described above, the angle of attack changes greatly even near the main plate. For this reason, the airflow is separated from the leading edge on the blade surface on the rotational direction side. As a result, there has been a problem that the noise reduction effect cannot be obtained sufficiently.

The present invention has been made in order to solve the above-described problems, and an object of the present invention is to suppress the separation of air currents on the blade surface in the entire width direction of the blade, and to achieve high-efficiency and low-noise centrifugal. To provide a fan, an air conditioner, and a refrigeration cycle apparatus.

The centrifugal fan according to the present invention includes a main plate having a main surface, a ring-shaped side plate facing the main surface, and a plurality of blades provided between the main plate and the side plate. On the inner peripheral side of the plurality of blades, the plurality of blades have a blade inlet angle. Each of the plurality of wings has a first region, a second region, and a third region. The first region is connected to the main plate. The third region is connected to the side plate. The second region is located between the first region and the third region. The blade inlet angle in the first region of at least one blade of the plurality of blades is greater than the blade inlet angle in the second region of the at least one blade. The blade inlet angle in the third region of the at least one wing is smaller than the blade inlet angle in the second region of the at least one wing.

According to the present invention, since the angle of attack of the blade is made uniform in the blade width direction, separation from the front edge of the blade surface side on the counter-rotation direction side and the blade surface side on the rotation direction side is suppressed, and high efficiency is achieved. Low noise can be achieved.

It is a perspective schematic diagram of the indoor unit of the air-conditioning apparatus according to Embodiment 1 of the present invention. It is a schematic diagram which shows the internal structure of the indoor unit of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a perspective schematic diagram of the centrifugal fan which concerns on Embodiment 1 of this invention. It is a partial expansion schematic diagram of the centrifugal fan according to Embodiment 1 of the present invention. It is the schematic diagram which looked at the blade | wing of the centrifugal fan which concerns on Embodiment 1 of this invention from the axial direction. It is a graph which shows the change of the blade inlet angle in the width direction of the blade | wing of the centrifugal fan which concerns on Embodiment 1 of this invention. It is a graph which shows the change of the angle of attack in the width direction of the blade | wing of a centrifugal fan. It is the schematic diagram which looked at the blade | wing of the centrifugal fan which concerns on Embodiment 2 of this invention from the axial direction. It is the partial expansion schematic diagram of the centrifugal fan which concerns on Embodiment 3 of this invention. It is a block diagram of the air conditioning apparatus which concerns on Embodiment 4 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
<Configuration and operation of indoor unit of air-conditioning apparatus according to this embodiment>
FIG. 1 is a schematic perspective view of an indoor unit of an air conditioner equipped with a centrifugal fan according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram showing the internal configuration of the indoor unit of the air-conditioning apparatus according to Embodiment 1 of the present invention.

As shown in FIGS. 1 and 2, the indoor unit of the air conditioner includes a case 1 installed behind the ceiling of a space to be air-conditioned. In addition, the shape of case 1 can employ | adopt arbitrary shapes. For example, as an example, the case 1 is formed in a rectangular parallelepiped shape. Case 1 includes an upper surface portion 1a, a lower surface portion 1b, and a side surface portion 1c.

The air outlet 2 is provided on one surface of the side surface portion 1c of the case 1. Arbitrary shapes can be employ | adopted for the shape of the blower outlet 2. FIG. The shape of the blower outlet 2 is a rectangular shape, for example. Moreover, the suction inlet 8 is formed in the surface on the opposite side to the surface in which the blower outlet 2 was formed among the side surface parts 1c of the case 1. FIG. Arbitrary shapes can be employ | adopted for the shape of the suction inlet 8. FIG. The shape of the suction port 8 is, for example, a rectangular shape. The suction port 8 may be provided with a filter for removing air.

In the case 1, a centrifugal fan 3, in which a bell mouth 5 is installed, a fan motor 4, a heat exchanger 6, and a spiral casing 7 are accommodated. The fan motor 4 is supported by a motor support fixed to the upper surface portion 1a of the case 1, for example. The fan motor 4 has a rotating shaft. The rotating shaft is arranged so as to extend in parallel to the surface of the side surface portion 1c where the inlet 8 is formed and the surface where the outlet 2 is formed. A centrifugal fan 3 which is a multiblade centrifugal fan is attached to the rotating shaft. At least one centrifugal fan 3 is attached to the rotating shaft. In the indoor unit shown in FIG. 2, two centrifugal fans 3 are attached to the rotating shaft. The centrifugal fan 3 creates a flow of air that is sucked into the case 1 from the suction port 8 and blown out from the blowout port 2 to the target space.

The heat exchanger 6 is disposed in the air flow path. The heat exchanger 6 adjusts the temperature of the air. The spiral casing 7 is provided so as to surround the centrifugal fan 3. The vortex casing 7 rectifies the air blown from the centrifugal fan 3. A bell mouth 5 is disposed at the suction port of the spiral casing 7. The bell mouth 5 is disposed at a position facing the suction port of the centrifugal fan 3. The bell mouth 5 rectifies the airflow flowing into the centrifugal fan 3. The space on the suction side of the bell mouth 5 and the space on the blow-out side of the spiral casing 7 are partitioned by a partition plate. Note that the configurations and modes of the bell mouth 5 and the heat exchanger 6 are not particularly limited, and well-known ones are used in the first embodiment.

In such a configuration, when the centrifugal fan 3 rotates, the air in the air-conditioned room is sucked into the suction port 8. The air sucked into the case 1 is guided by the bell mouth 5 and sucked into the centrifugal fan 3. Further, in the centrifugal fan 3, the sucked air is blown out to the outside in the radial direction of the centrifugal fan 3. The air blown out from the centrifugal fan 3 is supplied to the heat exchanger 6 after passing through the inside of the spiral casing 7. The air supplied to the heat exchanger 6 is subjected to heat exchange and humidity adjustment when passing through the heat exchanger 6. Thereafter, air is blown out from the air outlet 2 into the room.

<Configuration of centrifugal fan>
Next, the configuration of the centrifugal fan 3 will be described with reference to FIGS. FIG. 3 is a schematic perspective view of the centrifugal fan 3. FIG. 4 is an enlarged schematic view of the blade of the centrifugal fan shown in FIG. FIG. 5 is a schematic view of the blades of the centrifugal fan 3 as viewed from the axial direction. The centrifugal fan 3 includes a main plate 3a, a side plate 3c, and a plurality of blades 3d.

The main plate 3a rotates around the rotation axis. The side plate 3c is provided so as to face the main plate 3a and has a ring shape. The plurality of blades 3d are provided between the main plate 3a and the side plate 3c. On the inner peripheral side of the plurality of blades 3d, the plurality of blades 3d have blade inlet angles θ1 to θ3. Each of the plurality of blades 3d has a first region, a second region, and a third region. The first region is connected to the main plate 3a. The third region is connected to the side plate 3c. The second region is located between the first region and the third region. The blade inlet angle θ1 in the first region of at least one blade 3d of the plurality of blades 3d is larger than the blade inlet angle θ2 in the second region of the at least one blade 3d. The blade inlet angle θ3 in the third region of the at least one blade 3d is smaller than the blade inlet angle θ2 in the second region of the at least one blade 3d. Further, from a different point of view, in the blade 3d, the first position A that is separated from the main plate 3a by the first distance L1 in the direction from the main plate 3a to the side plate 3c, and the first position A that is larger than the first distance L1 from the main plate 3a. Consider a second position B separated by a distance L2. At this time, a region on the main plate 3a side from the first position A of the blade 3d is defined as a first region. A region from the first position A to the second position B of the blade 3d is defined as a second region. A region on the side plate 3c side from the second position B of the blade 3d is defined as a third region. The blade inlet angle θ1 on the inner peripheral side of the blade 3d in the first region is larger than the blade inlet angle θ2 in the second region of the blade 3d. The blade inlet angle θ3 in the third region of the blade is smaller than the blade inlet angle θ2 in the second region. In the centrifugal fan 3, the blade 3d includes an outer peripheral side edge 13b and an inner peripheral side edge 13a. Further, as can be seen from FIG. 4, in the direction from the main plate 3a to the side plate 3c, the width of the first region is the distance L1. The width of the second region is the distance (L2-L1). The width of the third region is the distance L3.

The main plate 3a has a disk shape. The main plate 3a has a boss 3b at the center thereof. The output shaft of the fan motor 4 (see FIG. 2) is connected to the center of the boss 3b. The centrifugal fan 3 is rotated by the driving force of the fan motor 4. The side plate 3c is disposed so as to face the main plate 3a. The plurality of blades 3d are provided so as to surround the rotation axis X in an annular shape from the main plate 3a toward the side plate 3c.

The plurality of blades 3d have the same shape. Each of the blades 3d has an inner peripheral side front edge 9a, an outer peripheral side rear edge 9b, a rotation direction side blade surface 9c, a counter rotation direction side blade surface 9d, and a side plate side end surface 9e. The blade surface 9c on the rotation direction side is a pressure surface. The blade surface 9d on the counter-rotation direction side is a suction surface. In the blade 3d, the blade surface 9c on the rotation direction side is concave with respect to the air path between the blades. In the blade 3d, the blade surface 9d on the side opposite to the rotation direction is convex with respect to the air path between the blades. The blade 3d is a forward-facing blade in which the outer peripheral side rear edge 9b is positioned to move forward in the rotational direction from the inner peripheral side front edge 9a.

Here, the blade inlet angles θ1, θ2, and θ3 at the inner circumferential front edge 9a of the blade 3d are the inner circumferential front edge 9a from the tangent line of the blade inscribed circle connecting the inner circumferential front edge 9a to the rotational direction side. Is defined by the angle formed by the tangent to the blade center line 9f. As shown in FIG. 5, the cross-sectional contour 9g on the inner peripheral side of the blade 3d in the first region is inclined toward the half rotation direction side as compared with the cross-sectional contour 9h on the inner peripheral side of the blade 3d in the second region. . Further, the cross-sectional contour 9i on the inner peripheral side of the blade 3d in the third region is inclined to the rotational direction side as compared with the cross-sectional contour 9h on the inner peripheral side of the blade 3d in the second region.

FIG. 6 shows a change in the blade inlet angle in the blade width direction in the centrifugal fan 3 according to the present embodiment. The horizontal axis in FIG. 6 indicates the position in the blade width direction, and the vertical axis indicates the blade inlet angle. As shown in FIG. 6, in the centrifugal fan 3 according to the present embodiment, the blade inlet angle θ2 in the second region described above is constant.

On the other hand, in the first region, the blade inlet angle θ1 gradually increases from the position A away from the main plate 3a by the first distance toward the main plate 3a. Specifically, the position of the end portion on the inner peripheral side of the blade center line 9f of the blade 3d gradually moves to the counter-rotation direction side toward the main plate 3a in the first region.

On the other hand, in the third region, the blade inlet angle θ3 gradually decreases from the position B away from the main plate 3a by the second distance toward the side plate 3c. Specifically, the position of the end portion on the inner peripheral side of the blade center line 9f of the blade 3d gradually moves to the rotational direction side toward the side plate 3c in the third region. The blade inlet angle θ is maximized at the end portion on the main plate 3a side and is minimized at the end portion on the side plate 3c side. As shown in FIG. 6, the blade inlet angle θ smoothly changes from the main plate 3a side to the side plate 3c side in the width direction of the blade 3d.

If the blade inlet angle θ is constant in the width direction of the blade 3d, the angle of attack changes in the width direction of the blade 3d as shown in FIG. Here, the angle of attack of the blade 3d is defined as the airflow inflow angle at the leading edge (inner peripheral side) of the blade 3d. Specifically, an angle formed by the direction of the airflow at the leading edge of the blade 3d from the tangent line of the circle around the rotation axis X to the rotation direction is defined as the angle of attack.

FIG. 7 is a graph showing the change in the angle of attack in the blade width direction when the blade inlet angle is constant in the width direction. The horizontal axis of FIG. 7 shows the position in the width direction of a wing | blade, and a vertical axis | shaft shows an angle of attack. As shown in FIG. 7, the angle of attack (also referred to as the inflow angle) varies in the vicinity of the main plate 3a and the side plate 3c. More specifically, in the region from the position of 20% of the distance from the main plate 3a to the side plate 3c, that is, the blade width, to the main plate 3a, the angle of attack increases as it approaches the main plate 3a. This is because the inflow wind speed between the blades is large in the vicinity of the main plate 3a. Further, in the region from the main plate 3a to the side plate 3c from the position of 80% of the blade width, the angle of attack decreases as the side plate 3c is approached. This is because the inflow speed between the blades is small on the side plate 3c side.

<Effect of centrifugal fan>
As shown in FIGS. 6 and 7, by separating the blade inlet angle θ <b> 1 on the main plate 3 a side, it is possible to suppress the separation of airflow at the leading edge on the blade surface 9 c (see FIG. 5) side on the rotational direction side. . Further, by reducing the blade inlet angle θ3 on the side plate 3c side, it is possible to suppress separation of airflow at the leading edge on the blade surface 9d (see FIG. 5) side on the counter-rotating direction side.

Considering the data shown in FIG. 7, in the centrifugal fan 3, the first distance L1 (see FIG. 4) indicating the first position A is the blade width in the direction from the main plate 3a to the side plate 3c (in FIG. 4). For example, the distance L2 + the distance L3) is 20% or less. In the centrifugal fan 3, the second distance L2 (see FIG. 4) indicating the second position B is, for example, 80% or more of the blade width in the direction from the main plate 3a to the side plate 3c. From a different point of view, in the direction from the main plate 3a to the side plate 3c, the width (distance L1) of the first region is 20% or less of the blade width in the direction from the main plate 3a to the side plate 3c. In the direction from the main plate 3a to the side plate 3c, the width of the third region (distance L3 in FIG. 4) is 20% or less of the blade width in the direction from the main plate 3a to the side plate 3c.

As described above, according to the centrifugal fan 3 of the first embodiment, the separation of the airflow from the main plate 3a to the side plate 3c can be suppressed. Therefore, high efficiency and low noise of the centrifugal fan 3 can be achieved by reducing the turbulence of the airflow. From a different point of view, by adjusting the blade inlet angle θ in the width direction of the blade 3d, it is possible to suppress variations in the angle of attack in the width direction of the blade 3d. For this reason, about the whole width direction area | region of the wing | blade 3d, peeling of the airflow can be suppressed on the blade surface 9d on the anti-rotation direction side and the blade surface 9c on the rotation direction side. As a result, a highly efficient and low noise centrifugal fan can be provided.

Further, in the centrifugal fan 3, the first distance may be 20% or less of the blade width in the direction from the main plate 3a to the side plate 3c. The first distance may be 15% or less of the blade width. Further, the second distance may be 80% or more of the blade width in the direction from the main plate 3a toward the side plate 3c. The second distance may be 85% or more of the blade width. In this case, the blade inlet angle θ can be adjusted particularly in a region where the angle of attack varies in the main plate 3a side or the side plate 3c side of the blade 3d.

(Embodiment 2)
<Configuration of centrifugal fan>
A second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic view of the blades of the centrifugal fan 3 according to the present embodiment as viewed from the axial direction.

The centrifugal fan 3 according to the second embodiment basically has the same configuration as the centrifugal fan 3 according to the first embodiment of the present invention, but the cross-sectional shape of the blade 3d is the centrifugal fan according to the first embodiment. 3 and different. That is, in the centrifugal fan 3 shown in FIG. 8, the blade thickness on the inner peripheral side of the blade 3d in the first region on the main plate 3a side is larger than the second region of the blade 3d. That is, the blade thickness increases in the counter-rotating direction. For this reason, the position of the edge part of the inner peripheral side of the blade center line 9f of the blade 3d in the first region is shifted from the second region to the counter-rotation direction side. More specifically, in the first region, the position of the end portion on the inner peripheral side of the blade center line 9f moves to the counter-rotation direction side as it approaches the main plate 3a.

Furthermore, in the centrifugal fan 3 shown in FIG. 8, the blade thickness on the inner peripheral side of the blade 3d in the third region on the side plate 3c side is smaller than the second region of the blade 3d. That is, the blade thickness is reduced in the rotational direction. For this reason, the position of the edge part of the inner peripheral side of the blade center line 9f of the blade 3d in the third region is shifted from the second region to the rotational direction side. More specifically, in the third region, as the side plate 3c is approached, the position of the end portion on the inner peripheral side of the blade center line 9f moves to the rotational direction side.

<Effect of centrifugal fan>
In the centrifugal fan 3, as shown in FIG. 8, the blade thickness on the inner peripheral side of the blade 3d in the first region is thicker than the blade thickness on the inner peripheral side of the blade 3d in the second region. The blade surface on the inner peripheral side of the blade 3d in the second region and on the counter-rotation direction side is opposed to the blade surface on the inner periphery side of the blade 3d in the first region and on the counter-rotation direction side. It protrudes. In the centrifugal fan 3, the blade thickness on the inner peripheral side of the blade 3d in the third region is thinner than the blade thickness on the inner peripheral side of the blade 3d in the second region. The blade surface on the inner peripheral side of the blade 3d in the second region and the blade surface on the counter-rotation direction side is recessed in the rotation direction on the inner periphery side of the blade 3d in the third region and on the counter-rotation direction side. It is out.

In this case, the same effect as the centrifugal fan 3 according to the first embodiment can be obtained. Further, the blade thickness on the inner peripheral side of the blade 3d gradually decreases in the width direction from the first region to the second region and the third region. For this reason, for example, when the wing 3d is molded using a mold, the mold can be separated from the wing 3d from the third region side, that is, the side plate 3c side.

Also, by increasing the blade thickness on the main plate 3a side, the distance between the blades on the main plate 3a side is small and the ventilation resistance can be increased. On the other hand, by reducing the blade thickness on the side plate 3c side, the distance between the blades is large on the side plate 3c side, and the ventilation resistance can be reduced. For this reason, the flow biased toward the main plate 3a can be made uniform in the blade width direction. As a result, friction loss and vortices caused by wind speed differences in the blade width direction can be suppressed. Therefore, high efficiency and low noise of the centrifugal fan 3 can be achieved.

(Embodiment 3)
<Configuration of centrifugal fan>
Next, Embodiment 3 of the present invention will be described with reference to FIG. FIG. 9 is a partially enlarged schematic view of the centrifugal fan 3 according to the present embodiment.

The centrifugal fan 3 according to the third embodiment basically has the same configuration as the centrifugal fan 3 according to the first embodiment of the present invention, but the shape of the blade 3d is the centrifugal fan 3 according to the first embodiment. Is different. That is, in Embodiment 3, the centrifugal fan 3 further includes a bell mouth 5 that is disposed on the side plate 3c side and includes an opening 5a that faces the wing 3d. The inner diameter of the opening 5a of the bell mouth 5 is larger than the inner diameter of the plurality of blades 3d arranged in an annular shape along the side plate 3c. On the inner peripheral side of the opening 5a of the bell mouth 5, the end 19a on the side plate 3c side of the wing 3d is inclined in the rotational direction. On the outer peripheral side of the opening 5a of the bell mouth 5, the end 19b on the side plate 3c side of the wing 3d faces the counter-rotation direction side from the end 19a on the side plate 3c side of the wing 3d on the inner peripheral side of the opening 5a. ing. The inner diameter of the plurality of blades 3d arranged in an annular shape means that the inner diameter side of the annular region occupied by the blades 3d when the plurality of blades 3d arranged in a ring shape are viewed from the axial direction. It means the diameter of the opening to be formed.

From a different point of view, the inner diameter of the downstream end of the opening 5a of the bell mouth 5 (see FIG. 2) is larger than the inner diameter of the blade 3d of the centrifugal fan 3. An inner peripheral front edge 9 a of the wing 3 d protrudes from the opening 5 a of the bell mouth 5. On the inner peripheral side of the downstream end of the opening 5a of the bell mouth 5, the side plate side blade end (end portion 19a) of the blade 3d is inclined in the rotational direction. On the outer peripheral side of the downstream end of the opening 5a of the bell mouth 5, the side plate side blade end (end portion 19b) of the blade 3d faces the counter-rotation direction side from the side plate side blade end on the inner peripheral side. Note that the end 19b of the blade 3d on the outer peripheral side of the opening 5a is also basically inclined in the rotational direction in the blade width direction. However, the inclination of the end portion 19b in the rotation direction is smaller than the inclination in the rotation direction in the blade width direction with respect to the end portion 19a of the blade 3d on the inner peripheral side from the opening 5a. Both the rotation direction side surface and the counter rotation direction side surface of the

end portions

19a and 19b are curved.

<Effect of centrifugal fan>
On the inner peripheral side of the bell mouth opening 5a, the airflow flows vertically toward the main plate. Therefore, the side plate side wing tip (end portion 19a) is directed to the rotation direction side so that the air flows from the bell mouth opening 5a side. The angle of attack against the airflow can be reduced. For this reason, it is possible to suppress separation of the airflow on the blade suction surface, which is the surface on the side opposite to the rotation direction of the blade 3d. On the outer peripheral side of the bell mouth opening 5a, airflow circulating in the direction of rotation in the scroll flows into the side plate side wing tip (end 19b). For this reason, the angle of attack can be reduced by directing the side plate side wing tip (end portion 19b) toward the counter-rotation direction side from the wing end portion 19a of the inner peripheral side of the bell mouth opening 5a.

According to the centrifugal fan 3 of the third embodiment configured as described above, in addition to the effects of the first embodiment, the separation of the airflow flowing from the

end portions

19a and 19b of the side plate side wings is further suppressed. it can.

(Embodiment 4)
FIG. 10 is a configuration diagram of an air-conditioning apparatus according to Embodiment 4 of the present invention. In the present embodiment, an air conditioner as a refrigeration cycle apparatus having an indoor unit 200 including the centrifugal fan described above will be described. The air conditioner shown in FIG. 10 includes an outdoor unit 100 and an indoor unit 200. The outdoor unit 100 and the indoor unit 200 are connected by a refrigerant pipe to form a refrigerant circuit. A refrigerant is circulated in the refrigerant circuit. Among the refrigerant pipes, a pipe through which a gaseous refrigerant (gas refrigerant) flows is referred to as a gas pipe 300. A pipe through which a liquid-containing refrigerant (a liquid refrigerant or a gas-liquid two-phase refrigerant may flow) flows is referred to as a liquid pipe 400.

In the present embodiment, the outdoor unit 100 includes a compressor 101, a four-way valve 102, an outdoor heat exchanger 103, an outdoor blower 104, and a throttle device (expansion valve) 105.

Compressor 101 compresses and discharges the sucked refrigerant. Here, the compressor 101 includes an inverter device or the like, and can arbitrarily change the capacity of the compressor 101 (the amount of refrigerant sent out per unit time) by arbitrarily changing the operation frequency. The four-way valve 102 switches the refrigerant flow between the cooling operation and the heating operation based on an instruction from a control device (not shown).

The outdoor heat exchanger 103 exchanges heat between the refrigerant and air (outdoor air). For example, it functions as an evaporator during heating operation, and performs heat exchange between the low-pressure refrigerant flowing from the liquid pipe 400 and the air. In this case, the outdoor heat exchanger 103 evaporates and vaporizes the refrigerant. Further, during the cooling operation, the outdoor heat exchanger 103 functions as a condenser. In this case, the refrigerant compressed in the compressor 101 flows into the outdoor heat exchanger 103 from the four-way valve 102 side. In the outdoor heat exchanger 103, heat is exchanged between the refrigerant and air, and the refrigerant is condensed and liquefied. The outdoor heat exchanger 103 is provided with an outdoor fan 104 having the centrifugal fan 3 described in the first to third embodiments in order to efficiently exchange heat between the refrigerant and the air. Regarding the outdoor blower 104, the rotational speed of the centrifugal fan 3 as the blower fan may be finely changed by arbitrarily changing the operating frequency of the fan motor by the inverter device. The expansion device 105 is provided to adjust the refrigerant pressure or the like by changing the opening degree.

On the other hand, the indoor unit 200 includes a load side heat exchanger 201 and a load side blower 202. The load side heat exchanger 201 performs heat exchange between the refrigerant and air. For example, it functions as a condenser during heating operation. In this case, the load-side heat exchanger 201 performs heat exchange between the refrigerant flowing in from the gas pipe 300 and the air, condensing the refrigerant and liquefying (or gas-liquid two-phase). As a result, the liquefied refrigerant flows out from the load side heat exchanger 201 to the liquid pipe 400 side. On the other hand, during the cooling operation, the load-side heat exchanger 201 functions as an evaporator. For example, the load-side heat exchanger 201 performs heat exchange between the refrigerant and the air that have been brought into a low pressure state by the expansion device 105. In this case, in the load-side heat exchanger 201, the refrigerant is vaporized by causing the refrigerant to take heat of the air and evaporate it. The refrigerant evaporated from the load side heat exchanger 201 flows out to the gas pipe 300 side. Further, the indoor unit 200 is provided with a load-side blower 202 for adjusting the flow of air for heat exchange. The operating speed of the load-side blower 202 is determined by, for example, user settings. Although not particularly limited, the centrifugal fan described in the first to third embodiments can be used for the load-side blower 202.

As described above, in the air conditioner according to the fourth embodiment, by using the blower described in the first to third embodiments for the outdoor unit 100 and further for the indoor unit 200, air volume reduction, noise suppression, and the like can be realized. Can do.

Although the contents of the present invention have been specifically described with reference to the preferred embodiments, various modifications can be made by those skilled in the art based on the basic technical idea and teachings of the present invention. It is self-explanatory.

For example, as an application example of the present invention, it can be widely used not only for indoor units constituting a refrigeration cycle apparatus, for example, indoor units for air conditioners, but also for various devices and facilities in which a centrifugal fan is installed.

Although the embodiments of the present invention have been described above, the above-described embodiments can be variously modified. The scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The present invention is particularly advantageously applied to a multiblade centrifugal fan.

1 case, 1a upper surface portion, 1b lower surface portion, 1c side surface portion, 2 outlet, 3 centrifugal fan, 3a main plate, 3b boss portion, 3c side plate, 3d blade, 4 fan motor, 5 bell mouth, 5a opening, 6 heat Exchanger, 7 vortex casing, 8 suction port, 9a front edge, 9b outer peripheral side rear edge, 9c, 9d blade surface, 9e side plate side end surface, 9f blade centerline, 9g, 9h, 9i cross-sectional contour, 13a inner peripheral side Edge, 13b Outer peripheral edge, 19a, 19b end, 100 outdoor unit, 101 compressor, 102 four-way valve, 103 outdoor heat exchanger, 104 outdoor blower, 105 throttle device, 200 indoor unit, 201 load side Heat exchanger, 202 load side blower, 300 gas piping, 400 liquid piping.

Claims

A main plate having a main surface;
A ring-shaped side plate facing the main surface;
A plurality of wings provided between the main plate and the side plate;
On the inner peripheral side of the plurality of blades, each of the plurality of blades has a blade inlet angle,
Each of the plurality of wings has a first region, a second region, and a third region, wherein the first region is connected to the main plate, the third region is connected to the side plate, Two regions are located between the first region and the third region,
The blade inlet angle in the first region of at least one blade of the plurality of blades is greater than the blade inlet angle in the second region of the at least one blade, and the blade of the at least one blade is The centrifugal fan, wherein the blade inlet angle in a third region is smaller than the blade inlet angle in the second region of the at least one blade.
The centrifugal fan according to claim 1, wherein in the direction from the main plate to the side plate, the width of the first region is 20% or less of the blade width in the direction from the main plate to the side plate.
The centrifugal fan according to claim 1 or 2, wherein in the direction from the main plate to the side plate, the width of the third region is 20% or less of the blade width in the direction from the main plate to the side plate.
The blade thickness on the inner peripheral side of the blade in the first region is thicker than the blade thickness on the inner peripheral side of the blade in the second region,
The blade surface on the inner peripheral side of the blade in the first region and on the counter-rotating direction side is opposite to the blade surface on the inner peripheral side of the blade in the first region and on the counter-rotating direction side. The centrifugal fan according to any one of claims 1 to 3, wherein the centrifugal fan projects toward the center.
The blade thickness on the inner peripheral side of the wing in the third region is thinner than the blade thickness on the inner peripheral side of the wing in the second region,
The blade surface on the inner peripheral side of the blade in the second region and on the counter-rotation direction side is opposed to the blade surface on the inner periphery side of the blade in the third region on the counter-rotation direction side. The centrifugal fan according to any one of claims 1 to 4, wherein the centrifugal fan is recessed.
Further comprising a bell mouth disposed on the side plate side and including an opening facing the wing;
The inner diameter of the opening of the bell mouth is larger than the inner diameter of the plurality of wings arranged annularly along the side plate,
On the inner peripheral side from the opening of the bell mouth, the end on the side plate side of the wing is inclined in the rotation direction,
On the outer peripheral side from the opening of the bell mouth, the end on the side plate side of the wing faces the counter-rotation direction side from the end on the side plate side of the wing on the inner peripheral side from the opening. The centrifugal fan according to any one of claims 1 to 5.
An air conditioner comprising the centrifugal fan according to any one of claims 1 to 6.
A refrigeration cycle apparatus comprising the centrifugal fan according to any one of claims 1 to 6.