WO2022234630A1

WO2022234630A1 - Blower, air conditioner, and refrigeration cycle device

Info

Publication number: WO2022234630A1
Application number: PCT/JP2021/017432
Authority: WO
Inventors: 惇司河野; 拓矢寺本; 裕樹宇賀神; 幸治山口; 哲央山下; 尚史池田
Original assignee: 三菱電機株式会社
Priority date: 2021-05-07
Filing date: 2021-05-07
Publication date: 2022-11-10
Also published as: JP7466765B2; JPWO2022234630A1; CN117222815A; US20240159238A1; EP4336045A4; EP4336045A1

Abstract

This blower comprises a cross flow fan having an impeller in which a plurality of blades are annularly arranged. When viewed from a cross-section perpendicular to the rotary axis of the cross flow fan, the blade has: a pressure surface having a concave shape on the rotation direction side; a suction surface having a convex shape on the counter-rotation direction side; an arc-shaped inner-peripheral-side end surface connecting the pressure surface and the suction surface on the inner peripheral side of the blade; and an arc-shaped outer-peripheral-side end surface connecting the pressure surface and the suction surface on the outer peripheral side of the blade. The outer-peripheral-side end surface is located to the rotation direction side relative to the inner-peripheral-side end surface. The pressure surface of the blade satisfies the relationship of (curvature of a pressure-side second curved surface)>(curvature of a pressure-side third curved surface)>(curvature of a pressure-side first curved surface). Lengths obtained when a pressure-side first range, pressure-side second range, and pressure-side third range of the pressure-surface-side blade surface of the blade are projected onto the chord line connecting the inner peripheral end and outer peripheral end of the blade, satisfy the relationship of (pressure-side third range length)>(pressure-side first range length)>(pressure-side second range length).

Description

Blowers, air conditioners and refrigeration cycle devices

The present disclosure relates to a blower, an air conditioner, and a refrigeration cycle device equipped with a cross-flow fan.

A blower arranged in the housing of the air conditioner has a fan casing and a cross-flow fan housed in the fan casing. A cross-flow fan has a plurality of blades arranged annularly around a rotation axis, and a disk-shaped support plate on which the plurality of blades are installed and which integrally supports the plurality of blades. It has an axially laminated configuration (see, for example, Patent Document 1). The impeller has a suction area and a blowout area in the circumferential direction, the suction area draws in air from the radially outer side to the radially inner side, and the blowing area generates an airflow that blows out from the radially inner side to the radially outer side. In Patent Document 1, the blade thickness of the blades extending in the radial direction of the impeller is constant, and the curvature of the outer peripheral side of the blades is made smaller than the curvature of the inner peripheral side, so that the separation amount of the airflow from the blades in the blowing region is being reduced.

Japanese Patent Application Laid-Open No. 2001-280288

In Patent Document 1, airflow separation from the blades in the blowout region of the impeller is suppressed, but airflow separation in the boundary region between the suction region and the blowout region of the impeller is not considered.

The present disclosure has been made in view of such points, and provides a blower, an air conditioner, and a refrigeration cycle device capable of suppressing airflow separation in the boundary region between the suction region and the discharge region of the impeller. intended to

The blower according to the present disclosure is a blower provided with a cross-flow fan having an impeller with a plurality of blades arranged in an annular shape, and the blades are, when viewed in a cross section perpendicular to the rotation axis of the cross-flow fan, the cross-flow fan A concave pressure surface on the rotational direction side, a convex suction surface on the counter-rotational direction side, an arc-shaped inner peripheral end face that connects the pressure surface and the suction surface on the inner peripheral side of the blade, and the blade and an arc-shaped outer peripheral end face that connects the pressure surface and the suction surface on the outer peripheral side of the blade, and the outer peripheral end face is located on the rotational direction side of the inner peripheral end face, and is located on the positive side of the blade. The pressure surface has, in order from the inner peripheral side of the impeller, a pressure side first curved surface, a pressure side second curved surface, and a pressure side third curved surface having different curvatures. Curvature > pressure side third curved surface curvature > pressure side first curved surface curvature > pressure side curvature , the inner peripheral end of the pressure side second curved surface and the outer peripheral end of the pressure side second curved surface are divided into three ranges, and from the inner peripheral side, the pressure side first range and the pressure side second range , pressure side third range, the length when each range is projected onto the chord line connecting the inner peripheral end and the outer peripheral end of the blade, pressure side third range length > pressure side third range It satisfies the relationship of range length of 1>second range length on the positive pressure side.

An air conditioner according to the present disclosure includes the blower described above, a housing that accommodates the blower, and a heat exchanger.

A refrigeration cycle apparatus according to the present disclosure includes the blower described above.

According to the present disclosure, in the blower, the pressure side first curved surface of the blade has the smallest curvature among the three curved surfaces forming the pressure side, and the pressure side first range length is greater than the pressure side second range length. , it is possible to suppress separation of the airflow in the boundary region between the suction region and the blowing region of the impeller.

1 is a schematic perspective view showing the configuration of an air conditioner provided with a blower according to Embodiment 1. FIG. 1 is a schematic vertical cross-sectional view of an air conditioner provided with a blower according to Embodiment 1. FIG. 2 is a schematic front view of the cross-flow fan of the blower according to Embodiment 1; FIG. 3 is a cross-sectional view of a part of the impeller of the blower according to Embodiment 1 cut in a direction perpendicular to the rotating shaft; FIG. FIG. 4 is an explanatory diagram of positive pressure side first to third ranges of the impeller of the blower according to Embodiment 1; FIG. 4 is an explanatory diagram of an inflow angle of an airflow with respect to an impeller of the blower according to Embodiment 1; FIG. 4 is a diagram showing a fan-blown air velocity distribution of a cross-flow fan of the blower according to Embodiment 1; FIG. 8 is a cross-sectional view of a part of the impeller of the blower according to Embodiment 2 cut in a direction perpendicular to the rotating shaft; FIG. 10 is an explanatory diagram of first to third ranges on the negative pressure side of the impeller of the blower according to Embodiment 2; FIG. 10 is a cross-sectional view of a part of the impeller of the blower according to Embodiment 3 cut in a direction perpendicular to the rotation axis; FIG. 11 is a cross-sectional view of a part of the impeller of the blower according to Embodiment 4 cut in a direction perpendicular to the rotation axis; FIG. 12 is a cross-sectional view of a part of the impeller according to Embodiment 5 cut in a direction perpendicular to the rotating shaft; FIG. 12 is a diagram showing the configuration of a refrigeration cycle apparatus according to Embodiment 6;

An embodiment of an air conditioner according to the present disclosure will be described below. In addition, the form of drawing is an example and does not limit this disclosure. In addition, the same reference numerals in each drawing are the same or equivalent, and this is common throughout the specification. Furthermore, in the drawings below, the size relationship of each component may differ from the actual size.

Embodiment 1.
FIG. 1 is a schematic perspective view showing the configuration of an air conditioner 1 equipped with a blower 7 according to Embodiment 1. FIG. FIG. 2 is a schematic vertical cross-sectional view of the air conditioner 1 including the blower 7 according to Embodiment 1. As shown in FIG. FIG. 3 is a schematic front view of cross-flow fan 11 of blower 7 according to the first embodiment.

[Overall Configuration of Air Conditioner]
The air conditioner 1 supplies conditioned air to an area to be air-conditioned, such as a room, by using a refrigeration cycle that circulates a refrigerant. A housing 2 of the air conditioner 1 has a main body 3 embedded in the ceiling of a room and a decorative panel 4 provided below the main body 3 . A heat exchanger 6 and a blower 7 are housed in the housing 2 . A drain pan 8 for recovering condensed water generated in the heat exchanger 6 is further provided in the housing 2 below the heat exchanger 6 .

The decorative panel 4 is formed with a suction port 4a that serves as an inlet for the airflow generated by the rotation of the blower 7 into the air conditioner 1, and a blowout port 4b that serves as an outlet for the airflow. A filter 5 for removing dust and the like in the air sucked into the housing 2 is arranged at the suction port 4a. A vertical airflow direction adjusting plate 9 and a horizontal airflow direction adjusting plate 10 for controlling the direction of the blown air are arranged in the air outlet 4b. A heat exchanger 6 is arranged on the upstream side of the air passage from the inlet 4a to the outlet 4b, and a blower 7 is arranged on the downstream side.

The air conditioner 1 sucks air generated by driving the blower 7 into the housing 2 from the suction port 4a, exchanges heat with the refrigerant in the heat exchanger 6, and then blows the air into the room from the blowout port 4b. to adjust the indoor temperature. The forward flow in the following description is the upstream airflow relative to an object, and the wakeward flow is the downstream airflow relative to an object. Although FIGS. 1 and 2 show an example in which the air conditioner 1 is a ceiling-suspended air conditioner indoor unit, the present invention is not limited to this. may be

[Blower 7]
The blower 7 includes a cross-flow fan 11 that generates airflow, a motor 12 (see FIG. 3) for rotating the cross-flow fan 11, and a fan casing 13 that guides the air blown out from the cross-flow fan 11 to the blowout port 4b. and have As shown in FIG. 3, the cross-flow fan 11 has a plurality of blades 21 annularly arranged around the rotation center of the rotation axis O of the motor 12, and a plurality of blades 21. The impeller 20 having the support plate 22 supported on the . The cross-flow fan 11 is installed horizontally so that the rotation axis O is in the horizontal direction of the housing 2 . In the following description, the direction in which the rotation axis O extends is called the axial direction, the direction perpendicular to the axial direction is called the radial direction, and the direction around the rotation axis O is called the circumferential direction.

The impeller 20 rotates in the direction of the solid line arrow in FIG. 2, sucks the airflow from the suction region E1, and blows the airflow from the blowing region E2. In the suction region E1, the airflow passes through the gap between the blades 21 (hereinafter referred to as "between the blades") from the radially outer side to the radially inner side. flow.

As shown in FIG. 2, the fan casing 13 has a rear guide 14 and a stabilizer 15. The rear guide 14 is a part that guides the air blown out from the impeller 20 to the outlet 4b. The rear guide 14 forms a spiral surface from the front end 14a of the rear guide 14 to the rear end 14b. The stabilizer 15 is a wall facing the rear guide 14 with the impeller 20 interposed therebetween. The stabilizer 15 is formed along the outer peripheral surface of the impeller 20 .

The suction area E1 and the blowout area E2 of the impeller 20 are defined by the rear guide 14 and the stabilizer 15. Specifically, of the regions obtained by dividing the entire circumference of the impeller 20 into two with the portion where the stabilizer 15 and the rear guide 14 facing each other as a boundary, the forward side of the region is the suction region E1, and the downstream side is the blowing region E2. be. A boundary region between the suction region E1 and the blowing region E2 in the circumferential direction of the impeller 20 is a switching region where the flow of air to be drawn in and the flow of air to be blown out are switched. There are two boundary areas, the front end 14a side of the rear guide 14 and the stabilizer 15 side. Hereinafter, the boundary area on the front end 14a side of the rear guide 14 is referred to as a first boundary area E3, and the boundary area on the stabilizer 15 side is referred to as a second boundary area E4.

Next, details of the blades 21 of the impeller 20 will be described.
FIG. 4 is a cross-sectional view of a portion of the impeller 20 of the blower 7 according to Embodiment 1 cut in a direction perpendicular to the rotation axis O. As shown in FIG. FIG. 5 is an explanatory diagram of the positive pressure side first to third ranges of the impeller 20 of the blower 7 according to the first embodiment.

When viewed in a cross section perpendicular to the rotation axis O, the blade 21 has a positive pressure surface 23 concave in the direction of rotation indicated by an arrow in FIG. , and an outer peripheral side end face 26 . The inner peripheral end surface 25 is an arcuate portion that is located on the inner peripheral side of the blade 21 and connects the pressure surface 23 and the suction surface 24 . The outer peripheral end surface 26 is an arc-shaped portion that is located on the outer peripheral side of the blade 21 and connects the pressure surface 23 and the suction surface 24 . The outer peripheral end face 26 is located on the rotational direction side with respect to the inner peripheral end face 25 . In addition, the blade 21 has an inner peripheral end 25-P, which is the inner peripheral end of the blade 21, and an outer peripheral end 26-P, which is the outer peripheral end of the blade 21. FIG. The inner peripheral end 25-P is included in the inner peripheral side end face 25, and the outer peripheral end 26-P is included in the outer peripheral side end face 26. FIG. 4, 23-P1 is the inner peripheral end of the pressure surface 23, and 23-P2 is the outer peripheral end of the pressure surface 23. As shown in FIG. 24-P1 is the inner peripheral edge of the suction surface 24, and 24-P2 is the outer peripheral edge of the suction surface 24. As shown in FIG.

The positive pressure surface 23 is composed of a plurality of curved surfaces. The plurality of curved surfaces are a pressure side first curved surface 23-1, a pressure side second curved surface 23-2, and a pressure side third curved surface 23-3 in order from the inner peripheral side. The pressure surface 23 is configured to satisfy the following relationship: curvature of pressure side second curved surface 23-2 > curvature of pressure side third curved surface 23 - 3 > curvature of pressure side first curved surface 23 - 1 . there is The pressure-side first curved surface 23-1 may be a flat surface with zero curvature.

As shown in FIG. 5, the blade 21 has a blade surface on the pressure side and a blade surface on the suction side, which are obtained by dividing the blade 21 by an imaginary center plane 27 in the blade thickness direction. The imaginary central plane 27 passes through the inner peripheral edge 25-P and the outer peripheral edge 26-P. The pressure side blade surface is divided into three ranges by the inner peripheral edge 23-2P1 of the pressure side second curved surface 23-2 and the outer peripheral edge 23-2P2 of the pressure side second curved surface 23-2. The three ranges are, in order from the inner peripheral side, a positive pressure side first range 23a-1, a positive pressure side second range 23a-2, and a positive pressure side third range 23a-3. The pressure side first range 23a-1 is a range from the inner peripheral end 25-P of the blade 21 to the inner peripheral end 23-2P1 of the pressure side second curved surface 23-2. The pressure side second extent 23a-2 is equal to the extent of the pressure side second curved surface 23-2. The pressure side third range 23 a - 3 is a range from the outer peripheral end 23 - 2 P 2 of the pressure side second curved surface 23 - 2 to the outer peripheral end 26 -P of the blade 21 .

Then, as shown in FIG. 5, the length when the first pressure side range 23a-1, the second pressure side range 23a-2 and the third pressure side range 23a-3 are projected onto the chord line l are defined, in order, as a pressure side first range length l _ps1 , a pressure side second range length l _ps2 , and a pressure side third range length l _ps3 . At this time, the blade 21 is configured to satisfy the relationship of pressure side third range length l _{ps3 > pressure side first range length l ps1} _> pressure side second range length l _ps2 . The chord line l is a straight line connecting the inner peripheral edge 25-P and the outer peripheral edge 26-P of the blade 21. FIG.

The action of the above configuration will be explained.

FIG. 6 is an explanatory diagram of the inflow angle of the airflow with respect to the impeller 20 of the blower 7 according to Embodiment 1. FIG. Focusing on one blade 21 in the impeller 20, the inflow angle of the airflow to the blade 21 changes depending on the position of the blade 21 in the rotational direction. The inflow angle is the angle between the tangent line L at the inner peripheral end 25-P with respect to the virtual center plane 27 of the blade thickness of the blade 21 and the direction of the airflow. Specifically, in FIG. 6, the airflow 30 shows the airflow when the blade 21 is positioned within the blowout region E2, and the inflow angle θ of the airflow 30 is θ1. An airflow 31 indicates an airflow when the blade 21 is positioned within the first boundary region E3, and the inflow angle θ of the airflow 31 is θ2.

When the inflow angle θ with respect to the blade 21 is relatively small like θ1, the airflow flows along the pressure surface 23, but when the inflow angle θ is relatively large like θ2, the airflow flows along the pressure surface 23. It is easy to peel off on the inner peripheral side. That is, in the first boundary region E3, the airflow is likely to separate on the inner peripheral side of the pressure surface 23 because the inflow angle θ of the airflow with respect to the blade 21 is relatively large. In the prior art, no consideration has been given to the fact that the airflow tends to separate on the inner peripheral side of the pressure surface due to the relatively large inflow angle in the blades in the region corresponding to the first boundary region E3. Noise was generated due to delamination.

In contrast, in Embodiment 1, the pressure surface 23 is formed by the curvature of the pressure side first curved surface 23-1 (see FIG. 4) on the inner peripheral side of the blade 21, which is the airflow inlet side of the blade 21. The smallest of the three curved surfaces. Therefore, even if the airflow detaches at the inner peripheral end 25-P of the blade 21, reattachment to the pressure surface 23 is likely to be promoted. In other words, airflow separation on the pressure surface 23 of the blade 21 in the first boundary region E3 is suppressed. By suppressing the airflow separation on the pressure surface 23 of the blades 21 in the first boundary region E3, the direction of the airflow between the blades in the first boundary region E3 is stabilized from the radially inner side to the radially outer side. . This corresponds to classifying the blades 21 in the first boundary region E3 on the side of the front end 14a of the rear guide 14 into the blades 21 in the blowout region E2. That is, the impeller 20 can expand the blowout area E2 toward the front end 14a of the rear guide 14 .

By the way, on the blowout side of the impeller 20, between the pressure surface 23 of the blade 21 and the suction surface 24 of the adjacent blade 21, the wind speed is small on the pressure surface 23 side, and the wind speed is large on the suction surface 24 side. Deviations in wind speed distribution tend to occur.

In the first embodiment, the pressure side first range length l _ps1 including the pressure side first curved surface 23-1 having the smallest curvature on the pressure side 23 on the airflow inlet side is the pressure side second range length l ps1 . longer than the length _lps2 . For this reason, the airflow that has flowed between the blades tends to stick to the pressure surface 23, and separation of the airflow on the pressure surface 23 is suppressed. In addition, the airflow that has flowed between the blades tends to stick to the pressure surface 23, so that the wind speed of the airflow on the pressure surface 23 is increased. By increasing the wind speed of the airflow on the pressure surface 23, the unevenness of the wind speed distribution between the blades is suppressed, and the wind speed distribution between the blades can be made uniform. In addition, since the airflow resistance between the blades is reduced by suppressing the unevenness of the wind speed distribution between the blades, the effect of reducing the fan input and noise can be obtained.

FIG. 7 is a diagram showing the fan-blown air velocity distribution of the cross-flow fan 11 of the blower 7 according to the first embodiment. In FIG. 7, the horizontal axis indicates a specific range in the circumferential direction of the impeller 20, and the vertical axis indicates the fan blowing air velocity [m/s]. The specific range in the circumferential direction of the impeller 20 is from a position in the circumferential direction of the impeller 20 facing the end of the stabilizer 15 on the upstream side, including the blowout region E2, to the upstream end 14a of the rear guide 14. It is a circumferential range up to the circumferential position of the opposing impeller.

In FIG. 7, (a) shows the first embodiment, and (b) shows the prior art. As is clear from FIG. 7, in the first embodiment, the blowout region is expanded toward the upstream end of the rear guide compared to the conventional technology. The expansion of the blowing area reduces the maximum flow velocity, and as a result, the airflow resistance is reduced, and the effect of reducing fan input and noise can be obtained.

As described above, the blower 7 of Embodiment 1 is a blower provided with the cross-flow fan 11 having the impeller 20 in which a plurality of blades 21 are annularly arranged. The pressure surface 23 of the blade 21 satisfies the following relationship: curvature of pressure side second curved surface 23-2 > pressure side third curved surface 23 - 3 curvature > pressure side first curved surface 23 - 1 . In addition, the pressure surface 23 of the blade 21 satisfies the relationship of pressure side third range length l _{ps3 > pressure side first range length l ps1} _> pressure side second range length l _ps2 .

Thus, in the pressure side 23 of the blade 21, the curvature of the pressure side first curved surface 23-1 is the smallest among the three curved surfaces forming the pressure side 23, and the pressure side first range length _lps1 is positive. longer than the compression side second range length _lps2 . As a result, the blower 7 can suppress airflow separation in the first boundary region E3, specifically, airflow separation on the pressure surface 23 of the blade 21 in the first boundary region E3. In addition, since the pressure side first range length l _ps1 is longer than the pressure side second range length l _ps2 , the blower 7 can increase the wind speed of the airflow on the pressure surface 23 . By increasing the wind speed of the airflow on the pressure surface 23, the fan 7 can suppress the unevenness of the wind speed distribution between the blades, reduce the airflow resistance between the blades, and reduce fan input and noise.

Embodiment 2.
FIG. 8 is a cross-sectional view of a part of the impeller 20 of the blower 7 according to Embodiment 2 cut in a direction perpendicular to the rotation axis O. FIG. FIG. 9 is an explanatory diagram of the negative pressure side first to third ranges of the impeller 20 of the blower 7 according to the second embodiment. Hereinafter, the second embodiment will be described with a focus on the configuration different from the first embodiment, and the configurations not described in the second embodiment are the same as those in the first embodiment.

The suction surface 24 of the blade 21 of Embodiment 2 is composed of a plurality of curved surfaces. As shown in FIG. 8, the plurality of curved surfaces are a negative pressure side first curved surface 24-1, a negative pressure side second curved surface 24-2, and a negative pressure side third curved surface 24-3 in order from the inner peripheral side. Among the plurality of curved surfaces, the negative pressure side first curved surface 24-1 is configured to have the smallest curvature. The negative pressure side first curved surface 24-1 may be a flat surface with zero curvature.

In addition, the blade 21 has a pressure side blade surface and a suction side blade surface which are obtained by dividing the blade 21 by a virtual center plane 27 in the blade thickness direction. As shown in FIG. 9, the suction side blade surface is divided into three sections bounded by an inner peripheral edge 24-2P1 of the suction side second curved surface 24-2 and an outer peripheral edge 24-2P2 of the suction side second curved surface 24-2. divided into ranges. The three ranges are a suction side first range 24a-1, a suction side second range 24a-2, and a suction side third range 24a-3. The suction side first range 24a-1 is a range from the inner peripheral end 25-P of the blade 21 to the inner peripheral end 24-2P1 of the suction side second curved surface 24-2. The suction side second extent 24a-2 is equal to the extent of the suction side second curved surface 24-2. The negative pressure side third range 24a-3 is a range from the outer peripheral end 24-2P2 of the negative pressure side second curved surface 24-2 to the outer peripheral end 26-P of the blade 21. FIG.

The blade 21 has a negative pressure side first area 24a-1, a negative pressure side second area 24a-2, and a negative pressure side third area 24a-3 when projected onto the chord line l. A pressure side first range length l _ss1 , a suction side second range length l _ss2 and a suction side third range length l _ss3 are defined. In FIG. 9, for convenience of illustration, the suction side first range length l _ss1 , the suction side second range length l _ss2 and the suction side third range length l _ss3 are not shown on the chord line l. , on a line parallel to the chord line l. The pressure-side first range length _{l_ps1} is configured longer than the suction-side first range length _{l_ss1} .

Further, a position _{P23-1P2 obtained} by projecting the outer peripheral end _23-1P2 of the pressure side first curved surface 23-1 onto the chord line l is located inside the center Pc of the chord line l. The outer peripheral end 23-1P2 of the pressure side first curved surface 23-1 is equal to the inner peripheral end 23-2P1 of the pressure side second curved surface 23-2.

The action of the above configuration will be described.
As described above, in the blade 21, the pressure side first curved surface 23-1 has the smallest curvature among the three curved surfaces forming the pressure side 23, and the suction side first curved surface 24-1 has a negative curvature. It is the smallest of the three curved surfaces forming the pressure surface 24 . The pressure side first range length _{l_ps1} is longer than the suction side first range length _{l_ss1} .

With the above configuration, the airflow flowing between the blades can easily follow the pressure surface 23, and the wind speed on the pressure surface 23 side increases. In the blowing region E2 of the impeller 20, the wind speed of the airflow between the blades on the pressure surface side of the blades 21 is smaller than that on the suction surface side. Uniform distribution can be achieved.

In the blade 21, a position _{P23-1P2 obtained} by projecting the outer peripheral end _23-1P2 of the pressure side first curved surface 23-1 onto the chord line l is located on the inner peripheral side of the center Pc of the chord line l. is doing. If the position _{P23-1P2 obtained} by projecting the outer peripheral end of the pressure side first curved surface 23-1 onto the chord line l is located on the outer peripheral side of the center _Pc of the chord line l, then the pressure surface The airflow that has flowed from the inner peripheral side to the outer peripheral side along the pressure surface 23 tends to be directed in the radial direction rather than in the circumferential direction on the outer peripheral side of the pressure surface 23 .

When the airflow flowing from the inner peripheral side to the outer peripheral side along the pressure surface 23 is directed in the circumferential direction on the outer peripheral side of the pressure surface 23, the following effects are obtained by the airflow directed in the circumferential direction. That is, since the airflow directed in the circumferential direction flows toward the suction surface 24 side of the adjacent blade 21, the airflow between the pressure surface 23 and the suction surface 24 of the adjacent blade 21 is transferred to the suction surface. It is pressed in the circumferential direction toward the 24 side. Therefore, it is possible to suppress separation of the airflow that has flowed from the inner peripheral side toward the negative pressure surface 24 on the outer peripheral side of the negative pressure surface 24 . On the other hand, if the airflow that flows from the inner peripheral side to the outer peripheral side along the pressure surface 23 is directed in the radial direction on the outer peripheral side of the pressure surface 23 , this effect cannot be obtained, and the airflow will flow on the outer peripheral side of the suction surface 24 . becomes easier to peel off.

In contrast, in the second embodiment, the position _{P23-1P2 obtained} by projecting the outer peripheral end _23-1P2 of the pressure side first curved surface 23-1 onto the chord line l is located inside the center Pc of the chord line l. located on the periphery. As a result, the direction of the airflow from the inner peripheral side to the outer peripheral side along the pressure side first curved surface 23-1 of the blade 21 becomes the circumferential direction toward the outer peripheral side. As a result, the effect described above is obtained, and separation of the air flow on the outer peripheral side of the suction surface 24 is suppressed.

As described above, in the second embodiment, the same effect as in the first embodiment can be obtained, and the above configuration makes the wind velocity distribution between the blades uniform and the airflow on the outer peripheral side of the suction surface 24 of the blade 21. Suppression of delamination can be achieved.

Embodiment 3.
FIG. 10 is a cross-sectional view of a part of the impeller 20 of the blower 7 according to Embodiment 3 cut in a direction perpendicular to the rotation axis O. FIG. The following description will focus on the configuration of the third embodiment that differs from the first and second embodiments, and the configurations not described in the third embodiment are the same as those of the first and second embodiments. be.

The suction surface 24 of the blade 21 of Embodiment 3 has a relationship of curvature of the second curved surface 24-2 on the suction side>curvature of the third curved surface 24-3 on the suction side>curvature of the first curved surface 24-1 on the suction side. is configured to satisfy Further, the blade 21 is configured to satisfy the relationship of suction side third range length l _ss3 > suction side second range length l _ss2 > suction side first range length l _ss1 .

In the blowing region E2 of the impeller 20, since the air velocity on the suction surface side is higher than that on the pressure surface side, the airflow tends to separate on the suction surface 24, and the airflow tends to separate more easily toward the outer peripheral side of the suction surface 24. For this reason, the suction side third range length l _ss3 , which is the outermost side of the suction surface 24 , is ensured to be the longest among the suction surfaces 24 . Also, if the curvature is large, separation of the airflow is likely to occur. Therefore, from the viewpoint of minimizing the curvature of the negative pressure side second curved surface 24-2 having the largest curvature, the negative pressure side second range length l _ss2 is ensured to be longer than the negative pressure side first range length l _ss1 . there is

With the above configuration, the impeller 20 further suppresses separation of the airflow from the suction surface 24 of the blade 21 in the blowout region E2.

According to the third embodiment, effects similar to those of the first and second embodiments can be obtained. can be further suppressed.

Embodiment 4.
FIG. 11 is a cross-sectional view of a part of the impeller 20 of the blower 7 according to Embodiment 4 cut in a direction perpendicular to the rotation axis O. As shown in FIG. The following description will focus on the configuration of Embodiment 4 that differs from Embodiments 1 to 3, and configurations not described in Embodiment 4 are the same as those of Embodiments 1 to 3. be.

In FIG. 11, the position A _ps on the pressure surface 23 is the position where the vertical distance L _ps from the chord line 1 on the pressure surface 23 is maximum when the blade 21 is viewed in a cross section perpendicular to the rotation axis O. On the blade 21, the position A _ss on the suction surface 24 is the position where the vertical distance L _ss from the blade chord line 1 on the suction surface 24 is the maximum when viewing the blade 21 in a cross section perpendicular to the rotation axis O. In the blade 21 of Embodiment 4, the position P _ps obtained by projecting the position A _ps on the pressure surface 23 onto the chord line l is higher than the position P _ss obtained by projecting the position A _ss on the suction surface 24 onto the chord line l. Located on the outer circumference side.

With the above configuration, a wide air passage width between the blades is ensured on the outer peripheral side in the blowing region E2, and an increase in the wind speed between the blades is suppressed. Since the wind speed increase between the blades is suppressed, the impeller 20 can obtain the effect of reducing fan input and noise.

According to Embodiment 4, effects similar to those of Embodiments 1 to 3 can be obtained, and the effect of reducing fan input and noise can be obtained due to the above configuration.

Embodiment 5.
In the first to fourth embodiments, the improvement of the airflow on the blowout side has been mentioned, but in the fifth embodiment, the improvement of the airflow on the suction side will be mentioned.

FIG. 12 is a cross-sectional view of a portion of the impeller 20 according to Embodiment 5 cut in a direction perpendicular to the rotation axis O. FIG. Hereinafter, the fifth embodiment will be described with a focus on the configuration different from the first to fourth embodiments, and the configurations not described in the fifth embodiment are the same as those in the first to fourth embodiments. be.

On the suction side of the impeller 20, the direction of the airflow is the direction indicated by the arrow, the outer peripheral side of the blade 21 is the inlet side of the airflow, and the inner peripheral side of the blade 21 is the outlet side of the airflow. Embodiment 5 specifies the position where the blade thickness of the blade 21 is maximized. In the blade 21 of Embodiment 5, a position P _28a obtained by projecting the center 28a of the maximum blade thickness 28 onto the chord line l (hereinafter referred to as the maximum blade thickness projection position P _28a ) is the pressure side first curved surface 23-1. is located in the range 23-1a projected onto the chord line l. In addition, the blade 21 has a maximum blade thickness projection position P _28a positioned within a range of 10% or more and 15% or less of the chord line l from the inner peripheral end 25-P of the blade 21 .

If the maximum blade thickness projection position P _28a is located inside the position 10% of the chord line l from the inner peripheral end 25-P of the blade 21, the wake in the direction of the airflow on the suction side The blade thickness of the side blades 21 increases, which causes an increase in airflow resistance and an increase in wind noise.

On the other hand, in the fifth embodiment, the maximum blade thickness projection position P _28a is the direction of the airflow on the outer circumference side of the position 10% of the chord line from the inner peripheral end 25-P of the chord line l, in other words, the direction of the airflow on the suction side. is located on the forward side of the As a result, the blade thickness of the blade 21 on the trailing side in the direction of the airflow on the suction side is reduced. For this reason, considering one blade 21 , the airflow flowing on the pressure surface 23 side of the blade 21 and the airflow flowing on the suction surface 24 side tend to merge in the wake of the blade 21 . Therefore, the blade 21 configured as described above can suppress the occurrence of a dead water area in the wake of the blade 21, reducing airflow resistance and suppressing wind noise.

Further, if the maximum blade thickness projection position P _28a is located on the outer peripheral side of the position 15% of the chord line l from the inner peripheral end 25-P of the blade 21, The effect of suppressing separation of the airflow is reduced. For this reason, the maximum blade thickness projected position P _28a is positioned within a range of 15% or less of the chord line l from the inner peripheral end 25-P of the blade 21. As shown in FIG.

According to Embodiment 5, the same effects as those of Embodiments 1 to 4 can be obtained, and the maximum blade thickness projection position P _28a is located 10 degrees from the inner peripheral end 25-P of the blade 21 to the chord line l. % or more and 15% or less, the following effects can be obtained. That is, the impeller 20 can reduce the draft resistance on the suction side and suppress the wind noise.

In the first to fifth embodiments, the blower 7 having the impeller 20 is installed in the indoor unit, but it may be installed in the outdoor unit. Similar effects can be obtained in this case as well.

Embodiment 6.
FIG. 13 is a diagram showing the configuration of a refrigeration cycle device 50 according to Embodiment 6. As shown in FIG. For indoor fan 202 of refrigeration cycle apparatus 50 according to Embodiment 6, fan 7 of any one of Embodiments 1 to 5 is used. Also, in the following description, the refrigeration cycle device 50 will be described as being used for air conditioning, but the refrigeration cycle device 50 is not limited to being used for air conditioning. The refrigerating cycle device 50 is used, for example, for refrigeration or air conditioning applications such as refrigerators, freezers, vending machines, air conditioners, refrigeration systems, and water heaters.

The refrigeration cycle device 50 according to Embodiment 6 heats or cools the room by transferring heat between the outside air and the indoor air via the refrigerant, thereby performing air conditioning. A refrigeration cycle device 50 according to Embodiment 6 has an outdoor unit 100 and an indoor unit 200 . The refrigerating cycle device 50 has a refrigerant circuit in which an outdoor unit 100 and an indoor unit 200 are connected by

refrigerant pipes

300 and 400 to circulate refrigerant. The refrigerant pipe 300 is a gas pipe through which a vapor-phase refrigerant flows, and the refrigerant pipe 400 is a liquid pipe through which a liquid-phase refrigerant flows. A gas-liquid two-phase refrigerant may flow through the refrigerant pipe 400 . In the refrigerant circuit of the refrigeration cycle device 50, the compressor 101, the flow switching device 102, the outdoor heat exchanger 103, the expansion valve 105, and the indoor heat exchanger 201 are sequentially connected via refrigerant pipes.

(Outdoor unit 100)
The outdoor unit 100 has a compressor 101 , a channel switching device 102 , an outdoor heat exchanger 103 and an expansion valve 105 . Compressor 101 compresses and discharges the sucked refrigerant. The channel switching device 102 is, for example, a four-way valve, and is a device that switches the direction of the coolant channel. The refrigeration cycle device 50 can realize heating operation or cooling operation by switching the refrigerant flow using the flow path switching device 102 based on an instruction from a control device (not shown).

The outdoor heat exchanger 103 exchanges heat between the refrigerant and the outdoor air. The outdoor heat exchanger 103 functions as an evaporator during heating operation, and performs heat exchange between the low-pressure refrigerant flowing from the refrigerant pipe 400 and the outdoor air to evaporate the refrigerant. The outdoor heat exchanger 103 functions as a condenser during cooling operation, and performs heat exchange between the refrigerant that has been compressed by the compressor 101 and has flowed in from the flow path switching device 102 and the outdoor air. Condense and liquefy. The outdoor heat exchanger 103 is provided with an outdoor fan 104 in order to increase the efficiency of heat exchange between the refrigerant and the outdoor air. The outdoor fan 104 may be equipped with an inverter device to change the operating frequency of the fan motor to change the rotational speed of the fan. The expansion valve 105 is a throttle device, functions as an expansion valve by adjusting the flow rate of the refrigerant flowing through the expansion valve 105, and adjusts the pressure of the refrigerant by changing the degree of opening. For example, if the expansion valve 105 is an electronic expansion valve or the like, the degree of opening is adjusted based on instructions from the control device.

(Indoor unit 200)
The indoor unit 200 has an indoor heat exchanger 201 that exchanges heat between a refrigerant and indoor air, and an indoor fan 202 that adjusts the flow of air with which the indoor heat exchanger 201 exchanges heat. During the heating operation, the indoor heat exchanger 201 functions as a condenser, performs heat exchange between the refrigerant flowing from the refrigerant pipe 300 and the indoor air, condenses the refrigerant and liquefies it. let it flow. The indoor heat exchanger 201 functions as an evaporator during cooling operation, and performs heat exchange between the refrigerant brought to a low pressure state by the expansion valve 105 and indoor air, causing the refrigerant to take heat from the air and evaporate. to vaporize it and flow out to the refrigerant pipe 300 side. Indoor fan 202 is provided so as to face indoor heat exchanger 201 . Air blower 7 according to Embodiments 1 to 5 is applied to indoor air blower 202 . The operating speed of the indoor fan 202 is determined by user settings. An inverter device may be attached to the indoor fan 202 to change the operating frequency of the fan motor (not shown) to change the rotation speed of the cross-flow fan.

[Example of operation of refrigeration cycle device 50]
Next, a cooling operation operation will be described as an operation example of the refrigeration cycle device 50 . The high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 101 flows into the outdoor heat exchanger 103 via the channel switching device 102 . The gas refrigerant that has flowed into the outdoor heat exchanger 103 is condensed by heat exchange with the outside air blown by the outdoor fan 104 , becomes a low-temperature refrigerant, and flows out of the outdoor heat exchanger 103 . The refrigerant that has flowed out of the outdoor heat exchanger 103 is expanded and decompressed by the expansion valve 105 to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant flows into the indoor heat exchanger 201 of the indoor unit 200, evaporates by heat exchange with the indoor air blown by the indoor fan 202, and becomes a low-temperature, low-pressure gas refrigerant in the indoor heat exchanger. 201. At this time, the indoor air that has been cooled by absorbing heat by the refrigerant becomes conditioned air, and is blown out from the outlet of the indoor unit 200 into the air-conditioned space. The gas refrigerant that has flowed out of the indoor heat exchanger 201 is sucked into the compressor 101 via the flow switching device 102 and compressed again. The above operations are repeated.

Next, the heating operation will be described as an example of the operation of the refrigeration cycle device 50. The high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 101 flows into the indoor heat exchanger 201 of the indoor unit 200 via the flow switching device 102 . The gas refrigerant that has flowed into the indoor heat exchanger 201 is condensed by heat exchange with the indoor air blown by the indoor fan 202 , becomes a low-temperature refrigerant, and flows out of the indoor heat exchanger 201 . At this time, the indoor air warmed by receiving heat from the gas refrigerant becomes conditioned air and is blown out from the outlet of the indoor unit 200 into the air-conditioned space. The refrigerant flowing out of the indoor heat exchanger 201 is expanded and decompressed by the expansion valve 105 to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant flows into the outdoor heat exchanger 103 of the outdoor unit 100, evaporates by heat exchange with the outside air blown by the outdoor fan 104, and becomes a low-temperature, low-pressure gas refrigerant in the outdoor heat exchanger 103. flow out from The gas refrigerant that has flowed out of the outdoor heat exchanger 103 is sucked into the compressor 101 via the flow switching device 102 and compressed again. The above operations are repeated.

Since the refrigeration cycle apparatus 50 according to Embodiment 6 includes the blower 7 according to Embodiments 1 to 5, it is possible to obtain the same effects as those of Embodiments 1 to 5 above.

The configuration shown in the above embodiment is an example, and can be combined with another known technique, and part of the configuration can be omitted or changed without departing from the scope of the invention. It is possible.

1 air conditioner, 2 housing, 3 main body, 4 decorative panel, 4a suction port, 4b outlet, 5 filter, 6 heat exchanger, 7 blower, 8 drain pan, 9 vertical wind direction adjustment plate, 10 left and right wind direction adjustment plate, 11 cross flow fan, 12 motor, 13 fan casing, 14 rear guide, 14a front end, 14b rear end, 15 stabilizer, 20 impeller, 21 blade, 22 support plate, 23 positive pressure surface, 23-1 positive pressure side second 1 curved surface 23-1P2 outer peripheral end 23-1a range 23-2 positive pressure side second curved surface 23-2P1 inner peripheral end 23-2P2 outer peripheral end 23-3 positive pressure side third curved surface 23a- 1 pressure side first area 23a-2 pressure side second area 23a-3 pressure side third area 24 suction surface 24-1 suction side first curved surface 24-2 suction side second area curved surface 24-2P1 inner peripheral end 24-2P2 outer peripheral end 24-3 negative pressure side third curved surface 24a-1 negative pressure side first range 24a-2 negative pressure side second range 24a-3 negative pressure side Third range, 25 inner peripheral side end face, 25-P inner peripheral end, 26 outer peripheral side end face, 26-P outer peripheral end, 27 virtual center plane, 27-P inner peripheral end, 28 maximum blade thickness, 28a center, 30 Airflow 31 Airflow 50 Refrigeration cycle device 100 Outdoor unit 101 Compressor 102 Flow switching device 103 Outdoor heat exchanger 104 Outdoor fan 105 Expansion valve 200 Indoor unit 201 Indoor heat exchanger 202 Indoor Blower, 300 refrigerant pipe, 400 refrigerant pipe, E1 suction area, E2 blow area, E3 first bounding area, E4 second bounding area, L tangent, L _ps vertical distance, L _ss vertical distance, O axis of rotation, P _28a maximum Blade thickness projection position, P _c center, l chord line, l _ps1 pressure side first range length, l _ps2 pressure side second range length, l _{ps3 pressure side third range length, l ss1} _suction side first range length l _{ss2 suction side second range length l ss3} _suction side third range length θ inlet angle.

Claims

A blower equipped with a cross-flow fan having an impeller with a plurality of annularly arranged blades,
When viewed in a cross section perpendicular to the rotation axis of the cross-flow fan, the blade has a concave positive pressure surface on the side of the rotation direction of the cross-flow fan, a convex suction surface on the counter-rotational direction side, and an inner side of the blade. An arc-shaped inner peripheral end surface on the peripheral side that connects the pressure surface and the suction surface, and an arc-shaped outer peripheral end surface that is on the outer peripheral side of the blade and connects the pressure surface and the suction surface. and
The outer peripheral side end face is located on the rotational direction side of the inner peripheral side end face,
The pressure surface of the blade has, in order from the inner peripheral side of the impeller, a first pressure-side curved surface, a second pressure-side curved surface, and a third pressure-side curved surface having different curvatures, and Satisfying the relationship: curvature of pressure side second curved surface>curvature of pressure side third curved surface>curvature of pressure side first curved surface,
The blade is divided into two by a virtual central plane in the thickness direction of the blade, and the blade surface on the pressure side is divided into the inner peripheral end of the second curved surface on the pressure side and the outer peripheral end of the second curved surface on the pressure side. is divided into three ranges, and from the inner peripheral side, the first range on the positive pressure side, the second range on the positive pressure side, and the third range on the positive pressure side. A fan whose length when projected onto a chord line connecting the outer peripheral edge satisfies the relationship: pressure side third range length>pressure side first range length>pressure side second range length.
The suction surface of the blade has, in order from the inner peripheral side of the impeller, a first suction-side curved surface, a second suction-side curved surface, and a third suction-side curved surface having different curvatures, and the first curved surface on the negative pressure side has a smaller curvature than the second curved surface on the negative pressure side and the third curved surface on the negative pressure side,
The blade surface on the suction side of the blade divided into two by the imaginary center plane is divided into three ranges bounded by the inner peripheral end of the second curved surface on the negative pressure side and the outer peripheral end of the second curved surface on the negative pressure side. When the innermost range of the division is defined as the suction side first range, and the length when the suction side first range is projected onto the chord line is defined as the suction side first range length ,
The pressure side first range length is longer than the suction side first range length, and a position obtained by projecting the outer peripheral end of the pressure side first curved surface onto the chord line is the chord line. 2. The blower according to claim 1, which is located on the inner peripheral side of the center.
the suction surface of the blade is configured to satisfy the following relationship: curvature of the second curved surface on the suction side>curvature of the third curved surface on the suction side>curvature of the first curved surface on the suction side;
The suction side blade surface is divided into three ranges by the inner peripheral end of the suction side second curved surface and the outer peripheral end of the suction side second curved surface, and the suction side first curved surface is divided into three ranges in order from the inner peripheral side. , the second range on the suction side, and the third range on the suction side, the length when each range is projected onto the chord line is the length of the third range on the suction side > the second range on the suction side 3. The blower according to claim 2, which satisfies the relationship of range length>negative pressure side first range length.
The position on the pressure surface where the vertical distance from the chord line is the maximum is projected onto the chord line, and the position on the suction surface where the vertical distance from the chord line is the maximum is the chord line. 4. The fan according to any one of claims 1 to 3, which is located on the outer peripheral side of the position projected on.
A position obtained by projecting the center of the blade thickness at the position where the blade has the maximum thickness on the chord line is located in a range obtained by projecting the pressure side first curved surface on the chord line, and The fan according to any one of claims 1 to 4, wherein the blade is located in a range of 10% or more and 15% or less of the chord line from the inner peripheral end of the blade.
An air conditioner comprising the blower according to any one of claims 1 to 5, a housing for housing the blower, and a heat exchanger.
A refrigeration cycle device comprising the blower according to any one of claims 1 to 5.