WO2024189889A1

WO2024189889A1 - Indoor unit of air conditioner, and air conditioner provided with same

Info

Publication number: WO2024189889A1
Application number: PCT/JP2023/010295
Authority: WO
Inventors: 惇司河野; 拓矢寺本; 奈穂安達
Original assignee: 三菱電機株式会社
Priority date: 2023-03-16
Filing date: 2023-03-16
Publication date: 2024-09-19

Abstract

An indoor unit (100) of an air conditioner is provided with: a housing (2) in which an intake port (3) and a blow-out port (4) are formed; a heat exchanger (7) that is provided in the interior of the housing (2); a first blower (20) that is provided in the interior of the housing (2), on the downstream side of the heat exchanger (7), and is composed of a through-flow fan rotating around a first rotational axis; a second blower (30) that is provided on both end sides of the first blower (20) in the first rotational axis direction and is composed of a centrifugal fan rotating around a second rotational axis; and a scroll casing (31) that is provided to the outer circumference of the second blower (30) and forms a blow-out passage (42b) of the second blower (30), wherein the second blower (30) is provided with a disc-shaped or ring-shaped main plate (32), a ring-shaped side plate (33) that is positioned facing the main plate (32), and a plurality of blades (36) that are connected to the main plate (32) at one end, are connected to the side plate (33) at the other end, and are arranged in the circumferential direction around the second rotational axis, and each of the plurality of blades (36) has an inner circumference end (31i) that is located on the second rotational axis side in the radial direction treating the second rotational axis as the center, an outer circumference end (36o) that is located further to the outer circumference side than the inner circumference end (36i) in the radial direction, a sirocco blade section (36a) that includes the outer circumference end (36o) and constitutes a front-facing blade in which the outlet angle is formed at an angle greater than 90 degrees, and a turbo blade section (36b) that includes the inner circumference end (36i) and constitutes a rear-facing blade.

Description

Indoor unit of air conditioner and air conditioner equipped with same

This disclosure relates to an indoor unit for an air conditioner and an air conditioner equipped with the same.

　Conventionally, there have been cross-flow fans used in indoor units of air conditioners and the like that prevent backflow at low flow rates and unstable flow at high flow rates, and suppress noise generation (see, for example, Patent Document 1).

The cross-flow fan of Patent Document 1 is characterized in that an impeller is configured with multiple blades around a central axis between partition plates provided at both ends in the central axis direction, and in that the rotation of the impeller causes air to flow through and blow out from one peripheral side of the impeller facing the suction side to the other peripheral side, multiple auxiliary blades are provided around the central axis on the outer surface of the partition plate, and an auxiliary casing is provided that covers the auxiliary blades rotating around the central axis on one peripheral side, and the auxiliary blades are configured as a centrifugal fan that draws in air in the central axis direction and blows out air to the other peripheral side.

And because this cross-flow fan has the above features, the auxiliary blades can suppress the drop in flow rate at the fan ends of the cross-flow fan, making the distribution of the blowing flow rate uniform along the central axis, and preventing backflow on the side walls caused by uneven flow rate at low flow rates.

JP 2002-357194 A

However, in the cross-flow fan of Patent Document 1, it is possible to use a centrifugal fan or a radial fan as the auxiliary blade centrifugal fan, but in that case, there is an issue that sufficient pressure recovery cannot be obtained between the blades and leading edge separation is likely to occur.

This disclosure has been made to solve the problems described above, and aims to provide an indoor unit for an air conditioner with improved pressure recovery, and an air conditioner equipped with the same.

The indoor unit of the air conditioner according to the present disclosure comprises a housing in which an intake port and an exhaust port are formed, a heat exchanger provided inside the housing, a first blower provided inside the housing downstream of the heat exchanger and configured as a cross-flow fan rotating about a first rotation shaft, a second blower provided on both ends of the first blower in the direction of the first rotation shaft and configured as a centrifugal fan rotating about a second rotation shaft, and a scroll casing provided on the outer periphery of the second blower and forming an exhaust air passage for the second blower, the second blower having a disk-shaped or annular The rotor blade has a main plate with a circular cross section, an annular side plate arranged opposite the main plate, and a plurality of blades arranged in a circumferential direction centered on the second rotating shaft, with one end connected to the main plate and the other end connected to the side plate. Each of the plurality of blades has an inner peripheral end located on the second rotating shaft side in a radial direction centered on the second rotating shaft, an outer peripheral end located on the outer side of the inner peripheral end in the radial direction, a sirocco blade portion that includes the outer peripheral end and forms a forward blade with an outlet angle greater than 90 degrees, and a turbo blade portion that includes the inner peripheral end and forms a backward blade.

The air conditioner disclosed herein is equipped with the above indoor unit and an outdoor unit.

In the air conditioner indoor unit and the air conditioner equipped therewith according to the present disclosure, each of the blades of the second blower has a sirocco blade portion that includes an outer circumferential end and forms a forward-facing blade with an outlet angle greater than 90 degrees, and a turbo blade portion that includes an inner circumferential end and forms a backward-facing blade, so that pressure recovery can be improved compared to when a sirocco fan or radial fan is used as the second blower.

1 is an external perspective view of an indoor unit of an air conditioner according to a first embodiment, as viewed from the front side. FIG. 1 is a schematic front view showing the internal configuration of an indoor unit of an air conditioner according to Embodiment 1. FIG. 3 is a schematic side view of the AA cross section of FIG. 2 as viewed in the direction of the arrows. 3 is a schematic side view of the BB cross section of FIG. 2 as viewed in the direction of the arrows. FIG. 3 is an enlarged schematic front view of part C in FIG. 2 . FIG. 2 is an external perspective view of the scroll casing according to the first embodiment, as viewed from the first blower side. FIG. 2 is an external perspective view of the scroll casing according to the first embodiment, as viewed from the side wall side. FIG. 2 is a schematic front view showing a first fan and a second fan according to the first embodiment. FIG. 2 is a schematic side view showing the first fan according to the first embodiment. FIG. 4 is a schematic side view showing the second fan according to the first embodiment. FIG. 10 is a partial enlarged view of the first blower shown in FIG. 9 . FIG. 11 is a partial enlarged view of the second blower shown in FIG. 10 . FIG. 2 is a perspective view showing a second fan according to the first embodiment. FIG. 6 is an enlarged schematic front view of a portion D in FIG. 5 . 15 is a schematic plan view of part E in FIG. 14 as viewed in the direction of the arrow. FIG. 6 is an enlarged schematic front view of a modified example of the portion D in FIG. 5 . 11 is a schematic front view showing an enlarged view of a portion of the internal configuration of an indoor unit of an air conditioner according to a second embodiment. FIG. FIG. 11 is a schematic front view showing an enlarged view of a portion of the internal configuration of an indoor unit of an air conditioner according to embodiment 3. FIG. 13 is a diagram showing a configuration example of an air conditioner according to a fourth embodiment.

Below, embodiments of the present disclosure are described with reference to the drawings. Note that the forms of the components shown in the entire specification are merely examples, and are not limited to the forms described in the specification. In particular, the combinations of the components are not limited to the combinations in each embodiment, and components described in other embodiments can be applied to other embodiments. Also, the size relationships between the components in the following drawings may differ from the actual relationships.

In addition, in the following explanation, terms indicating directions such as "up," "down," "right," "left," "front," and "rear" are used as appropriate to facilitate understanding, but these are for the purpose of explanation and do not limit the embodiments. In the embodiments, terms such as "up," "down," "right," "left," "front," and "rear" are used when looking at the indoor unit of the air conditioner from the front.

Embodiment 1.
FIG. 1 is an external perspective view of an indoor unit 100 of an air conditioner according to embodiment 1, as viewed from the front side. As shown in FIG. 1, the indoor unit 100 has a rear case 1, the rear surface 1a of which is attached to a wall surface, and a box-shaped housing 2, which is attached to the front surface of the rear case 1 and forms an outer shell. The housing 2 is formed with an inlet 3 for mainly drawing indoor air into the interior and an outlet 4 for supplying conditioned air to an area to be air-conditioned. The inlet 3 is formed as an opening in the upper part of the housing 2, and the outlet 4 is formed as an opening in the lower part of the housing 2. An openable front design panel 5 is attached to the front surface of the housing 2. In addition, side walls 2a are provided on the left and right sides of the housing 2. Note that, although a wall-mounted indoor unit is described in the embodiment, a floor-standing or ceiling cassette type indoor unit may also be used, in which case the positions of the inlet and outlet depend on the shape of the indoor unit.

FIG. 2 is a schematic front view showing the internal configuration of the indoor unit 100 of the air conditioner according to the first embodiment. FIG. 3 is a schematic side view of the A-A cross section of FIG. 2, seen in the direction of the arrows. FIG. 4 is a schematic side view of the B-B cross section of FIG. 2, seen in the direction of the arrows. FIG. 5 is a schematic front view of an enlarged C section of FIG. 2. FIG. 6 is an external perspective view of the scroll casing 31 according to the first embodiment, seen from the first blower 20 side. FIG. 7 is an external perspective view of the scroll casing 31 according to the first embodiment, seen from the side wall 2a side. The dashed arrows in FIG. 2, FIG. 3, and FIG. 5 indicate the flow of air (air current).

2 to 5, the inside of the indoor unit 100 is provided with a first blower 20 and two second blowers 30 that suck in indoor air from the intake port 3 and blow out conditioned air from the exhaust port 4. The two second blowers 30 are provided on both ends of the first blower 20 in the direction of the rotation axis O (the direction in which the shaft 15 described later extends, and the left-right direction in FIG. 2). In addition, a heat exchanger 7 is provided in the air passage from the intake port 3 to the exhaust port 4, with its longitudinal direction being the left-right direction, and which creates conditioned air by exchanging heat between the refrigerant and the indoor air. On the downstream side of the first blower 20, a front air passage wall 8 and a rear air passage wall 9 are provided, which form a first exhaust air passage 42a from the downstream side of the first blower 20 to the exhaust port 4. Furthermore, on the downstream side of each second blower 30, a scroll casing 31 is provided, which forms a second exhaust air passage 42b from the downstream side of the second blower 30 to the exhaust port 4. In the following, the rear air passage wall 9 is also referred to as the casing.

The heat exchanger 7 is disposed downstream of the intake port 3 and upstream of the first blower 20 and the two second blowers 30. For example, a fin-tube type heat exchanger or the like may be used for this heat exchanger 7. The heat exchanger 7 exchanges heat between the refrigerant and the indoor air. For example, during cooling operation, it functions as an evaporator, evaporating and vaporizing the refrigerant. During heating operation, it functions as a condenser, condensing and liquefying the refrigerant.

The first blower 20 and the two second blowers 30 are arranged upstream of the air outlet 4 and downstream of the heat exchanger 7. The first blower 20 is a cross-flow fan, and the second blower 30 is a centrifugal fan. An air passage front wall 8 and an air passage rear wall 9 are provided on the outer periphery of the first blower 20. A scroll casing 31 is provided on the outer periphery of the second blower 30. These components communicate an air flow path within the housing 2. The air passage front wall 8 has a tongue portion 8a and is located on the front side and below the first blower 20. The tongue portion 8a is provided on the front side and below the first blower 20. The air passage rear wall 9 is located on the rear side of the first blower 20. The scroll casing 31 has a tongue portion 31a and is provided on the side wall 2a side of the first blower 20. The tongue portion 31a is provided on the front and lower side of the second blower 30.

Here, in the case of a cross-flow fan generally used in an indoor unit of an air conditioner, the flow becomes unstable at low air volume or high pressure loss, and reverse suction occurs at both left and right ends of the indoor unit, which may worsen the input power and noise to the motor. Therefore, in the first embodiment, the second blower 30 is provided at both ends of the rotation axis O direction of the first blower 20, and a cross-flow fan is used for the first blower 20, and a centrifugal fan with higher aerodynamic characteristics at high static pressure than a cross-flow fan is used for the second blower 30. This eliminates reverse suction at both left and right ends of the indoor unit 100 even at low air volume or high pressure loss, so that the increase in input power to the motor (not shown) and the increase in noise (hereinafter referred to as an increase in input noise) due to reverse suction can be suppressed, and the occurrence of condensation due to contact of moist air with the surface of the air outlet 4 due to reverse suction during cooling operation can be suppressed.

6 and 7, the scroll casing 31 has a recess 31b on the first blower 20 side that is recessed toward the side wall 2a and in which the second blower 30 is disposed. A bell mouth 51 is provided on the opposite side of the scroll casing 31 from the first blower 20 (the side wall 2a side) to form an intake port 31d that takes in air sucked in from the intake port 3 into the second blower 30 in the scroll casing 31. An exhaust port 31e is formed on the exhaust port 4 side of the scroll casing 31 to blow air out of the scroll casing 31. An air duct partition plate 50 is formed on the heat exchanger 7 side of the scroll casing 31. This air duct partition plate 50 is a plate-shaped member that protrudes toward the heat exchanger 7 from the outer circumferential end of the scroll casing 31 on the heat exchanger 7 side. The air passage partition plate 50 divides the air passage from the air intake 3 to the upstream side of the first blower 20 and the two second blowers 30 into a first air intake passage 41a from the air intake 3 to the upstream side of the first blower 20 and a second air intake passage 41b from the air intake 3 to the upstream side of the second blower 30. The air passage partition plate 50 may be in contact with the heat exchanger 7, or there may be a gap between the air passage partition plate 50 and the heat exchanger 7.

Here, if the suction ratio of the second blower 30 becomes excessively large during high pressure loss, the operation of the first blower 20 may become unstable. Therefore, in the first embodiment, the suction air duct from the suction port 3 to the upstream sides of the first blower 20 and the two second blowers 30 is divided into a first suction air duct 41a and a second suction air duct 41b by an air duct partition plate 50. In this way, the first blower 20 is not affected by the second blower 30, and the operation of each is stabilized, thereby suppressing an increase in input noise.

FIG. 8 is a schematic front view showing the first blower 20 and the second blower 30 according to the first embodiment. FIG. 9 is a schematic side view showing the first blower 20 according to the first embodiment. FIG. 10 is a schematic side view showing the second blower 30 according to the first embodiment. FIG. 11 is a partially enlarged view of the first blower 20 shown in FIG. 9. FIG. 12 is a partially enlarged view of the second blower 30 shown in FIG. 10. FIG. 13 is a perspective view showing the second blower 30 according to the first embodiment. Note that FIG. 8 shows only a part of the right side of the first blower 20 and the right second blower 30, and does not show a part of the left side of the first blower 20 and the left second blower 30. The solid arrows in FIG. 9, FIG. 10, and FIG. 13 indicate the direction of rotation of the first blower 20 or the second blower 30.

As shown in Figures 8 and 9, the first blower 20 is configured with one blower unit consisting of two disk-shaped or annular partition plates 21 and a plurality of first blades 26 connected to the two partition plates 21 facing each other in the direction of the rotation axis O and arranged in the circumferential direction centered on the rotation axis O, and is configured with approximately 7 to 14 blower units connected in the direction of the rotation axis O. Also, as shown in Figures 8 and 10, the second blower 30 is equipped with a disk-shaped or annular main plate 32, an annular side plate 33 arranged facing the main plate 32 in the direction of the rotation axis O, and a plurality of second blades 36 connected to the main plate 32 and the side plate 33 and arranged in the circumferential direction centered on the rotation axis O.

The main plate 32 is disposed on the first blower 20 side, and the side plate 33 is disposed on the bellmouth 51 side. In addition, in the first embodiment, of the multiple partition plates 21 of the first blower 20, the one closest to the second blower 30 also serves as the main plate 32 of the second blower 30, and they are the same. However, this is not limited to this, and the partition plate 21 closest to the second blower 30 and the main plate 32 may each be provided as separate bodies.

Furthermore, the outer diameter of the partition plate 21 of the first blower 20 and the outer diameter of the side plate 33 of the second blower 30 are the same length. In this way, by making the outer diameter of the partition plate 21 of the first blower 20 and the outer diameter of the side plate 33 of the second blower 30 the same length, the tongue portion 8a of the air passage front wall 8 of the first blower 20 and the tongue portion 31a of the scroll casing 31 of the second blower 30 can be in the same position when viewed from the side, which simplifies the parts that make up the indoor unit 100 and improves manufacturability.

As shown in FIG. 10, the second blade 36 has a sirocco blade portion 36a including an outer peripheral end 36o and configured as a forward blade (a blade facing in the direction of rotation), and a turbo blade portion 36b including an inner peripheral end 36i and configured as a rearward blade (a blade facing in the opposite direction of rotation). In the radial direction of the second blower 30, the sirocco blade portion 36a constitutes the outer peripheral side of the second blade 36, and the turbo blade portion 36b constitutes the inner peripheral side of the second blade 36. That is, in the radial direction of the second blower 30, the second blade 36 is configured in the order of the turbo blade portion 36b and the sirocco blade portion 36a from the rotation axis O toward the outer peripheral side. In the second blade 36, the sirocco blade portion 36a and the turbo blade portion 36b are formed integrally. 13, the turbo blade portion 36b constitutes the leading edge 36i1 of the second blade 36, and the sirocco blade portion 36a constitutes the trailing edge 36o1 of the second blade 36. In addition, if the region constituting the sirocco blade portion 36a of the second blade 36 in the radial direction of the second blower 30 is defined as the sirocco region 36ar, and the region constituting the turbo blade portion 36b of the second blade 36 is defined as the turbo region 36br, the turbo region 36br is larger than the sirocco region 36ar.

10, the outlet angle of the sirocco blade portion 36a of the second blade 36 is α1, and the outlet angle of the turbo blade portion 36b of the second blade 36 is α2. The outlet angle α1 is defined as the angle between the tangent TL1 of the circle C3 and the tangent TL2 of the outer peripheral end 36o on the negative pressure surface 36n side at the intersection of the arc of the circle C3 centered on the rotation axis O and the outer peripheral end 36o. The outlet angle α2 is defined as the angle between the tangent TL3 of the circle C2 and the tangent TL4 of the turbo blade portion 36b on the negative pressure surface 36n side at the intersection of the arc of the circle C2 centered on the rotation axis O and the turbo blade portion 36b. In this case, the outlet angle α1 of the sirocco blade portion 36a of the second blade 36 is an angle larger than 90 degrees, and the outlet angle α2 of the turbo blade portion 36b of the second blade 36 is an angle smaller than 90 degrees. In addition, the surface of the second blade 36 facing the direction of rotation is the positive pressure surface 36p, and the surface opposite the positive pressure surface 36p is the negative pressure surface 36n.

As shown in Figure 11, the inlet angle of the first blade 26 is β1, and as shown in Figure 12, the inlet angle of the second blade 36 is β2. As shown in Figure 11, the inlet angle β1 is defined as the angle between the tangent TL5 of the circle C4 and the tangent TL6 of the inner circumferential ends 26i, 36i on the

negative pressure surface

26n, 36n side at the intersection of the arc of the circle C4 centered on the rotation axis O and the inner circumferential end 26i. As shown in Figure 12, the inlet angle β2 is defined as the angle between the tangent TL7 of the circle C1 and the tangent TL8 of the inner circumferential end 36i on the negative pressure surface 36n side at the intersection of the arc of the circle C1 centered on the rotation axis O and the inner circumferential end 36i. In this case, the inlet angle β2 of the second blade 36 is smaller than the inlet angle β1 of the first blade 26. In addition, the surface of the first blade 26 facing the direction of rotation is the positive pressure surface 26p, and the surface opposite the positive pressure surface 26p is the negative pressure surface 26n.

Here, since the left and right ends of the indoor unit 100 where the second blower 30 is located have high ventilation resistance, leading edge separation is likely to occur on the negative pressure surface 36n of the second blade 36 when the airflow flows between the second blades 36. Therefore, in the first embodiment, the inlet angle β2 of the second blade 36 at the left and right ends of the indoor unit 100 where ventilation resistance is high is made smaller than the inlet angle β1 of the first blade 26 at the center of the indoor unit 100, thereby reducing leading edge separation of the airflow.

12, the blade length WL of the second blade 36 is defined as the distance between the inner circumferential end 26i and the outer circumferential end 36o in a cross section perpendicular to the second rotation axis of the second blower 30. The second blade 36 of the second blower 30 is formed such that the blade length WL in a first region R1 closer to the main plate 32 than the intermediate position CT (see FIG. 13) in the direction of the rotation axis O is longer than the blade length WL in a second region R2 closer to the side plate 33 than the intermediate position CT in the direction of the rotation axis O.

In this way, by forming the second blade 36 so that the blade length WL in the first region R1 is longer than the blade length WL in the second region R2, the airflow can easily flow to the main plate 32 side, and the air speed distribution blowing out from the end side of the indoor unit 100 can be made uniform.

When the first blower 20 rotates in the direction of the arrow R in FIG. 3, it sucks in air between the first blades 26 on the first intake air passage 41a side and blows out air between the first blades 26 on the first exhaust air passage 42a side. When the second blower 30 rotates in the direction of the arrow R in FIG. 4, it sucks in air that has passed through the heat exchanger 7 from the bell mouth 51 provided on the opposite side (side wall 2a side) of the scroll casing 31 from the first blower 20, and blows out air from the outlet 31e of the scroll casing 31. The second blowers 30 are provided on both the left and right ends of the first blower 20 and are connected by the same shaft 15. In other words, the first rotating shaft, which is the rotating shaft of the first blower 20, and the second rotating shaft, which is the rotating shaft of the second blower 30, are the same. The first blower 20 and the two second blowers 30 are driven to rotate by the same motor (not shown).

In the first embodiment, the first blower 20 and the two second blowers 30 are connected by the same shaft 15, but the present invention is not limited to this. A separate shaft 15 may be provided for each of the first blower 20 and the two second blowers 30, the partition plate 21 and the main plate 32 closest to the second blower 30 may be provided as separate bodies, and the first blower 20 and the two second blowers 30 may be installed in parallel in the left-right direction, and each may be driven to rotate by a separate motor (not shown).

As shown in FIG. 3, the intake port 3 is provided with a finger guard (not shown) and a filter 13. The outlet port 4 is provided with an up-down air deflector 11 that changes the blowing direction in the up-down direction. The first outlet air passage 42a, which runs from the downstream side of the first blower 20 to the outlet port 4, is provided with a left-right air deflector 12 that changes the blowing direction in the left-right direction.

As shown in Figures 2 and 5, a plate member 16 is provided within the housing 2 to prevent the air that has passed through the second intake air passage 41b from flowing anywhere other than the bell mouth 51 of the scroll casing 31, that is, to prevent the air that has passed through the second intake air passage 41b from leaking into the housing 2.

Next, the air flow in the indoor unit 100 of the air conditioner according to the embodiment will be briefly described. First, indoor air flows into the indoor unit 100 from the intake port 3 formed in the upper part of the housing 2 by the first blower 20 and the two second blowers 30. At this time, dust contained in the air is removed by the filter 13. When this indoor air passes through the heat exchanger 7, it is heated or cooled by the refrigerant flowing through the heat exchanger 7 to become conditioned air. Then, the conditioned air is divided into one that flows through the first intake air duct 41a, the first blower 20, and the first exhaust air duct 42a, and one that flows through the second intake air duct 41b, the second blower 30, and the second exhaust air duct 42b, and is blown out from the exhaust port 4 formed in the lower part of the housing 2 to the outside of the indoor unit 100, that is, to the area to be air-conditioned. At this time, the direction of the conditioned air blown out to the area to be air-conditioned is changed by the up-down air deflector 11 and the left-right air deflector 12.

The first distance W1 from the point on the air passage rear wall 9 of the first blower 20 closest to the rear surface 1a of the rear case 1 to the rear surface 1a of the rear case 1 is shorter than the second distance W2 from the point on the scroll casing 31 of the second blower 30 closest to the rear surface 1a of the rear case 1 to the rear surface 1a of the rear case 1 (i.e., W1 < W2).

When there is a high pressure loss, if the suction ratio of the second blower 30 becomes excessive, the operation of the first blower 20 may become unstable. Therefore, in the first embodiment, as described above, the first distance W1 from the part of the air passage rear wall 9 of the first blower 20 closest to the rear surface 1a of the rear case 1 to the rear surface 1a of the rear case 1 is made shorter than the second distance W2 from the part of the scroll casing 31 of the second blower 30 closest to the rear surface 1a of the rear case 1 to the rear surface 1a of the rear case 1, thereby increasing the pressure loss of the second outlet air passage 42b, suppressing the excessive suction ratio of the second blower 30, stabilizing the operation of the first blower 20 and the second blower 30, and suppressing an increase in input noise.

Also, as shown in Figures 2 and 5, the maximum point (vertex) X of the height of the scroll casing 31 in the direction of the rotation axis O is located between the outer peripheral end E1 and the inner peripheral end E2 on the heat exchanger 7 side of the scroll casing 31. In other words, the height of the scroll casing 31 in the direction of the rotation axis O gradually increases from the outer peripheral end E1 on the heat exchanger 7 side of the scroll casing 31 toward the position of maximum point X on the suction port 31d side, and gradually decreases from the position of maximum point X toward the inner peripheral end E2 on the heat exchanger 7 side.

When the suction port 3 is formed at the top of the housing 2, the air flowing into the second blower 30 flows into the suction port 31d through the gap between the scroll casing 31 and the side wall 2a of the housing 2, resulting in high pressure loss in the second suction air passage 41b. However, by positioning the maximum point X of the height of the scroll casing 31 in the direction of the rotation axis O between the outer peripheral end E1 and the inner peripheral end E2 on the heat exchanger 7 side of the scroll casing 31, the second suction air passage 41b expands from the position of the maximum point X toward the inner peripheral end E2 on the heat exchanger 7 side, reducing pressure loss in the second suction air passage 41b and reducing the input noise of the second blower 30.

Also, as shown in Figs. 2 and 5, the maximum point X of the height of the scroll casing 31 in the direction of the rotation axis O is located inside the outer end 7a of the heat exchanger 7 in the direction of the rotation axis O. In other words, in the direction of the rotation axis O, the outer end of the second blower 30 on the side of the suction port 31d is located inside the outer end 7a of the heat exchanger 7. In this way, air can be sucked into the suction port 31d of the scroll casing 31 from the suction port 3 formed in the upper part of the housing 2, and it is not necessary to form an suction port on the side of the housing 2, so the structure of the indoor unit 100 is simplified and manufacturability can be improved. In addition, in the direction of the rotation axis O, the suction port 31d of the scroll casing 31 is located within the installation range of the heat exchanger 7. As a result, the air that has passed through the heat exchanger 7 flows directly into the second blower 30, reducing the pressure loss in the second suction air passage 41b, and the input noise of the second blower 30 can be reduced.

Also, as shown in Figures 2 and 5, the width H1 of the second intake air passage 41b, which is the distance from the air passage partition plate 50 to the outer end 7a of the heat exchanger 7 in the direction of the rotation axis O, is equal to the width H2 of the second exhaust air passage 42b, which is the height of the scroll casing 31, or the second intake air passage 41b and the second exhaust air passage 42b are formed so that the width H1 of the second intake air passage 41b is greater than the width H2 of the second exhaust air passage 42b.

In this way, by forming the second intake air duct 41b and the second exhaust air duct 42b so that H1 = H2 or H1 > H2 (i.e., H1 ≥ H2), the pressure loss in the second intake air duct 41b is reduced, and the input noise of the second blower 30 can be reduced.

14 is a front view of an enlarged D portion of FIG. 5. FIG. 15 is a plan view of an E portion of FIG. 14 as viewed in the direction of the arrow. FIG. 16 is a front view of an enlarged D portion of FIG. 5. As shown in FIG. 8, the second blower 30 has a main plate 32 on the first blower 20 side in the direction of the rotation axis O, and a side plate 33 on the opposite side (side wall 2a side) of the first blower 20 in the direction of the rotation axis O. As shown in FIG. 14 and FIG. 15, a gap G of about 4 mm is formed between the outer peripheral end 32a of the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side. In addition, in the direction of the rotation axis O, the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side are arranged so as to coincide with each other, that is, so that they all overlap (face each other). As shown in FIG. 16, the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side may be arranged slightly offset in the direction of the rotation axis O so that they partially overlap (face each other).

In this way, by arranging the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side so that they coincide or partially overlap in the direction of the rotation axis O, and minimizing the gap G between the outer peripheral end 32a of the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side, it is possible to prevent air from being blown out from anywhere other than the outlet 31e of the scroll casing 31, in other words, to prevent air from leaking from the scroll casing 31, thereby reducing the input noise of the second blower 30.

As described above, the indoor unit 100 of the air conditioner according to the first embodiment comprises a housing 2 in which an intake port 3 and an exhaust port 4 are formed, a heat exchanger 7 provided inside the housing 2, a first blower 20 provided inside the housing 2 downstream of the heat exchanger 7 and configured as a cross-flow fan rotating about a first rotation axis, a second blower 30 provided on both ends of the first blower 20 in the direction of the first rotation axis and configured as a centrifugal fan rotating about a second rotation axis, and a scroll casing 31 provided on the outer periphery of the second blower 30 and forming an outlet air passage for the second blower 30, the second blower 30 being a disk-shaped or The rotor blade 30 includes an annular main plate 32, an annular side plate 33 arranged opposite the main plate 32, and a plurality of blades arranged in a circumferential direction centered on the second rotating shaft, with one end connected to the main plate 32 and the other end connected to the side plate 33. Each of the blades has an inner circumferential end 36i located on the second rotating shaft side in the radial direction centered on the second rotating shaft, an outer circumferential end 36o located on the outer side of the inner circumferential end 36i in the radial direction, a sirocco blade portion 36a including the outer circumferential end 36o and constituting a forward blade with an outlet angle α1 greater than 90 degrees, and a turbo blade portion 36b including the inner circumferential end 36i and constituting a backward blade.

According to the indoor unit 100 of the air conditioner according to the first embodiment, each of the blades of the second blower 30 has a sirocco blade portion 36a that includes the outer circumferential end 36o and forms a forward-facing blade with an outlet angle α1 greater than 90 degrees, and a turbo blade portion 36b that includes the inner circumferential end 36i and forms a backward-facing blade, so that pressure recovery can be improved compared to when a sirocco fan or a radial fan is used as the second blower 30. In addition, by providing the second blower 30 on both ends of the first blower 20 in the first rotation axis direction, configuring the first blower 20 as a cross-flow fan, and configuring the second blower 30 as a centrifugal fan that has higher aerodynamic characteristics at high static pressure than a cross-flow fan, reverse suction is eliminated at both left and right ends of the indoor unit 100 even at low air volume or high pressure loss, so that an increase in input noise due to reverse suction can be suppressed, and condensation caused by contact of moist air with the surface of the air outlet 4 due to reverse suction during cooling operation can also be suppressed.

Furthermore, in the indoor unit 100 of the air conditioner according to embodiment 1, the first blower 20 has multiple blades arranged in a circumferential direction centered on the first rotation axis, and the inlet angle β2 of the multiple blades of the second blower 30 is smaller than the inlet angle β1 of the multiple blades of the first blower 20.

In the air conditioner indoor unit 100 according to the first embodiment, the inlet angle β2 of the blades of the second blower 30 at both ends of the first blower 20, where the ventilation resistance is high, is made smaller than the inlet angle β1 of the blades of the first blower 20 between the second blowers 30, thereby reducing leading edge separation of the airflow.

In addition, in the indoor unit 100 of the air conditioner according to embodiment 1, the scroll casing 31 has a bell mouth 51 that forms an intake port 31d that draws air into the scroll casing 31, and the bell mouth 51 is provided on the opposite side to the first blower 20 in the direction of the second rotation axis.

According to the indoor unit 100 of the air conditioner according to the first embodiment, by providing a bell mouth 51 on the opposite side to the first blower 20, the flow coming in from the bell mouth 51 can be rectified and the air passage pressure loss in the intake air passage can be reduced. In addition, the first blower 20 and the second blower 30 can be configured as one unit, and by measuring one location, it is possible to determine whether the gap G between the outer peripheral end 32a of the main plate 32 and the inner peripheral end 31f on the main plate 32 side of the scroll casing 31 is secured, making tolerance management easier.

Furthermore, in the indoor unit 100 of the air conditioner according to embodiment 1, the multiple blades of the second blower 30 are formed so that the blade length WL in the first region R1 closer to the main plate 32 than the intermediate position CT in the second rotational shaft direction is longer than the blade length WL in the second region R2 closer to the side plate 33 than the intermediate position CT in the second rotational shaft direction.

In the air conditioner indoor unit 100 according to the first embodiment, the blades of the second blower 30 are formed so that the blade length WL in the first region R1 is longer than the blade length WL in the second region R2, which makes it easier for the airflow to flow to the main board 32 side, and makes it possible to uniformize the distribution of the air speed blowing out from the end side of the indoor unit 100.

Furthermore, the indoor unit 100 of the air conditioner according to embodiment 1 is provided with a casing that is provided on the outer periphery of the first blower 20 and forms the airflow path of the first blower 20, and the first distance W1 from the point of the casing closest to the rear surface to the rear surface is shorter than the second distance W2 from the point of the scroll casing 31 closest to the rear surface to the rear surface.

When there is a high pressure loss, if the suction ratio of the second blower 30 becomes excessive, there is a risk that the operation of the first blower 20 will become unstable. Therefore, according to the indoor unit 100 of the air conditioner of embodiment 1, by making the first distance W1 shorter than the second distance W2, the pressure loss in the second outlet air passage 42b is increased, and the suction ratio of the second blower 30 is prevented from becoming excessive, the operation of the first blower 20 and the second blower 30 can be stabilized, and an increase in input noise can be suppressed.

In addition, in the indoor unit 100 of the air conditioner according to embodiment 1, the maximum point X of the height in the second rotation axis direction of the scroll casing 31 is located between the outer circumferential end E1 and the inner circumferential end E2 on the heat exchanger 7 side of the scroll casing 31.

In the indoor unit 100 of the air conditioner according to the first embodiment, the maximum point X of the height in the second rotation axis direction of the scroll casing 31 is positioned between the outer peripheral end E1 and the inner peripheral end E2 on the heat exchanger 7 side of the scroll casing 31, so that the second intake air passage 41b expands from the position of the maximum point X toward the inner peripheral end E2 on the heat exchanger 7 side, and the pressure loss in the second intake air passage 41b is reduced, thereby reducing the input noise of the second blower 30.

Furthermore, in the indoor unit 100 of the air conditioner according to embodiment 1, the maximum point X of the height of the scroll casing 31 in the second rotational axis direction is located inside the outer end 7a of the heat exchanger 7 in the second rotational axis direction.

According to the indoor unit 100 of the air conditioner according to the first embodiment, air can be sucked into the suction port 31d of the scroll casing 31 from the suction port 3 formed in the upper part of the housing 2, and there is no need to form an suction port on the side of the housing 2, which simplifies the structure of the indoor unit 100 and improves manufacturability. Also, in the direction of the rotation axis O, the suction port 31d of the scroll casing 31 is located within the installation range of the heat exchanger 7. As a result, air that has passed through the heat exchanger 7 flows directly into the second blower 30, which reduces the pressure loss in the second suction air passage 41b and reduces the input noise of the second blower 30.

In addition, in the indoor unit 100 of the air conditioner according to embodiment 1, the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side are arranged to coincide or partially overlap in the second rotation axis direction, and a gap G is formed between the outer peripheral end 32a of the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side.

According to the indoor unit 100 of the air conditioner according to the first embodiment, the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side are arranged to coincide or partially overlap in the second rotation axis direction, and the gap G between the outer peripheral end 32a of the main plate 32 and the inner peripheral end 31f of the scroll casing 31 on the main plate 32 side is minimized, thereby preventing air from being blown out from anywhere other than the air outlet 31e of the scroll casing 31, in other words, preventing air from leaking from the scroll casing 31, thereby reducing the input noise of the second blower 30.

In addition, in the indoor unit 100 of the air conditioner according to embodiment 1, the first blower 20 has a disk-shaped or annular partition plate 21, and the second blower 30 has an annular side plate 33, and the outer diameter of the partition plate 21 and the outer diameter of the side plate 33 are the same length.

In the indoor unit 100 of the air conditioner according to embodiment 1, the outer diameter of the partition plate 21 of the first blower 20 and the outer diameter of the side plate 33 of the second blower 30 are made the same length, so that the tongue portion 8a of the air passage front wall 8 of the first blower 20 and the tongue portion 31a of the scroll casing 31 of the second blower 30 can be in the same position when viewed from the side, simplifying the components that make up the indoor unit 100 and improving manufacturability.

In addition, in the indoor unit 100 of the air conditioner according to embodiment 1, the scroll casing 31 has an air duct partition plate 50 that divides the intake air duct from the intake port 3 to the upstream side of the first blower 20 and the second blower 30 into a first intake air duct 41a from the intake port 3 to the upstream side of the first blower 20 and a second intake air duct 41b from the intake port 3 to the upstream side of the second blower 30.

In the indoor unit 100 of the air conditioner according to the first embodiment, the air duct partition plate 50 divides the intake air duct from the air inlet 3 to the upstream side of the first blower 20 and the two second blowers 30 into the first intake air duct 41a and the second intake air duct 41b. This prevents the first blower 20 from being affected by the second blower 30, stabilizing the operation of each blower, and suppresses an increase in input noise.

In addition, in the indoor unit 100 of the air conditioner according to embodiment 1, the width H1 of the second intake air duct 41b is equal to or greater than the width H2 of the second exhaust air duct 42b.

In the air conditioner indoor unit 100 according to the first embodiment, by forming the second intake air duct 41b and the second exhaust air duct 42b so that H1 = H2 or H1 > H2 (i.e., H1 ≥ H2), the pressure loss in the second intake air duct 41b is reduced, and the input noise of the second blower 30 can be reduced.

Embodiment 2.
Hereinafter, the second embodiment will be described, but explanations of parts that overlap with the first embodiment will be omitted, and parts that are the same as or equivalent to the first embodiment will be given the same reference numerals.

FIG. 17 is a schematic front view showing an enlarged view of part of the internal structure of the indoor unit 100 of the air conditioner according to embodiment 2. Note that FIG. 17 is a schematic front view showing an enlarged view of part C in FIG. 2, similar to FIG. 5. Also, the dashed arrows in FIG. 17 indicate the air flow (air current).

As shown in FIG. 17, in the second embodiment, a bell mouth 51 that forms the suction port 31d is provided on the first blower 20 side of the scroll casing 31. In other words, in the second embodiment, the position where the suction port 31d of the scroll casing 31 is formed is on the opposite side in the direction of the rotation axis O to the scroll casing 31 in the first embodiment.

In this way, by forming the suction port 31d of the scroll casing 31 on the first blower 20 side, when a centrifugal fan is used for the second blower 30, when the air that flows in from the suction port 31d on the first blower 20 side flows out of the scroll casing 31 of the second blower 30, it flows out toward the main plate 32 of the centrifugal fan located at both the left and right ends of the indoor unit 100, so the wind speed blowing out from both the left and right sides of the outlet 4 becomes high. Therefore, even in an operating range where the pressure loss inside the indoor unit 100 is high, there is no reverse suction at both the left and right ends of the indoor unit 100, so it is possible to suppress an increase in input noise due to reverse suction, and it is possible to suppress the occurrence of condensation caused by contact of moist air with the surface of the outlet 4 due to reverse suction during cooling operation.

As described above, in the indoor unit 100 of the air conditioner according to the second embodiment, the scroll casing 31 has a bell mouth 51 that forms an intake port 31d that draws air into the scroll casing 31, and the bell mouth 51 is provided on the first blower 20 side in the second rotation axis direction.

According to the indoor unit 100 of the air conditioner according to the second embodiment, when the air flowing in from the intake port 31d on the first blower 20 side flows out from the scroll casing 31 of the second blower 30, it flows out toward the main plate 32 of the centrifugal fan located at both the left and right ends of the indoor unit 100, so the wind speed blowing out from both the left and right sides of the outlet 4 becomes high. Therefore, even in the operating range where the pressure loss inside the indoor unit 100 is high, there is no reverse suction at both the left and right ends of the indoor unit 100, so it is possible to suppress the increase in input noise due to reverse suction, and it is possible to suppress the occurrence of condensation caused by contact of moist air with the surface of the outlet 4 due to reverse suction during cooling operation.

Embodiment 3.
Hereinafter, the third embodiment will be described, but explanations of parts that overlap with the first and second embodiments will be omitted, and parts that are the same as or equivalent to the first and second embodiments will be given the same reference numerals.

FIG. 18 is a schematic front view showing an enlarged view of part of the internal structure of the indoor unit 100 of the air conditioner according to embodiment 3. Note that FIG. 18 is a schematic front view showing an enlarged view of part C in FIG. 2, similar to FIG. 5. Also, the dashed arrows in FIG. 18 indicate the flow of air (air current).

As shown in FIG. 18, in the third embodiment, bell mouths 51 that form suction ports 31d are provided on the first blower 20 side of the scroll casing 31 and on the opposite side of the first blower 20 (side wall 2a side). In other words, in the third embodiment, in the direction of the rotation axis O, the suction ports 31d of the scroll casing 31 are formed on the first blower 20 side and on the opposite side of the first blower 20 (side wall 2a side), and air is sucked in from both sides of the second blower 30.

By drawing in air from both sides of the second blower 30 in the direction of the rotation axis O, the pressure loss in the heat exchanger 7 or the first intake air passage 41a is relatively low, and the intake air volume of the second blower 30 can be ensured even in an operating range where the aerodynamic characteristics of the first blower 20 are high. Therefore, the operation of the first blower 20 and the second blower 30 can be stabilized, and an increase in input noise can be suppressed.

As described above, in the indoor unit 100 of the air conditioner according to the third embodiment, the scroll casing 31 has a bell mouth 51 that forms an intake port 31d that draws air into the scroll casing 31, and the bell mouth 51 is provided on the first blower 20 side and on the opposite side to the first blower 20 in the second rotation axis direction.

According to the indoor unit 100 of the air conditioner according to the third embodiment, by drawing in air from both sides of the second blower 30 in the second rotational axis direction, the pressure loss in the heat exchanger 7 or the first intake air passage 41a is relatively low, and the intake air volume of the second blower 30 can be ensured even in an operating range where the aerodynamic characteristics of the first blower 20 are high. Therefore, the operation of the first blower 20 and the second blower 30 can be stabilized, and an increase in input noise can be suppressed.

Embodiment 4.
Hereinafter, the fourth embodiment will be described, but explanations of parts that overlap with the first to third embodiments will be omitted, and the same parts as or corresponding parts to the first to third embodiments will be given the same reference numerals.

FIG. 19 is a diagram showing an example of the configuration of an air conditioner according to embodiment 4. Note that in FIG. 19, the components described in embodiments 1 to 3 operate in the same manner. Also, the solid arrows in FIG. 19 indicate the flow of refrigerant during cooling operation, and the dashed arrows indicate the flow during heating operation.

As shown in FIG. 19, the air conditioner according to the fourth embodiment has an indoor unit 100 and an outdoor unit 200, as described in the first to third embodiments, connected by a gas refrigerant pipe 300 and a liquid refrigerant pipe 400. The indoor unit 100 has a heat exchanger 7. The outdoor unit 200 has a compressor 210, a flow switching device 220, an outdoor heat exchanger 230, and a throttling device 240. This air conditioner has a refrigerant circuit in which the compressor 210, the flow switching device 220, the outdoor heat exchanger 230, the throttling device 240, and the heat exchanger 7 are connected in sequence by refrigerant pipes including the gas refrigerant pipe 300 and the liquid refrigerant pipe 400, and the refrigerant circulates.

The compressor 210 compresses the sucked refrigerant and discharges it. Although not particularly limited here, the compressor 210 may be configured to change its capacity (the amount of refrigerant pumped out per unit time) by arbitrarily changing the operating frequency, for example, by an inverter circuit. The flow path switching device 220 is, for example, a four-way valve, which switches between cooling operation and heating operation by switching the flow direction of the refrigerant. Note that instead of a four-way valve, a combination of a two-way valve and a three-way valve may be used as the flow path switching device 220.

The outdoor heat exchanger 230 exchanges heat between the refrigerant and the outdoor air. For example, during heating operation, it functions as an evaporator, evaporating and vaporizing the refrigerant. During cooling operation, it functions as a condenser, condensing and liquefying the refrigerant.

The throttling device 240 reduces the pressure of the refrigerant to expand it. For example, if it is configured as an electronic expansion valve, the opening degree is adjusted based on instructions from a control device (not shown) or the like.

Next, we will explain the flow of refrigerant during cooling and heating operation of the air conditioner according to embodiment 4.

During cooling operation, as shown by the solid line in FIG. 19, the flow path switching device 220 is switched so that the refrigerant discharged from the compressor 210 flows into the outdoor heat exchanger 230. The low-temperature, low-pressure refrigerant is then compressed by the compressor 210 and discharged as high-temperature, high-pressure gas refrigerant. The high-temperature, high-pressure gas refrigerant discharged from the compressor 210 flows into the outdoor heat exchanger 230 via the flow path switching device 220. The high-temperature, high-pressure gas refrigerant that flows into the outdoor heat exchanger 230 condenses while releasing heat to the outdoor air, becoming high-pressure liquid refrigerant. The high-pressure liquid refrigerant that flows out of the outdoor heat exchanger 230 is then reduced in pressure by the throttling device 240 to a low-temperature, low-pressure two-phase refrigerant, and then flows out of the outdoor unit 200, passes through the liquid refrigerant piping 400, and flows into the indoor unit 100. The low-temperature, low-pressure two-phase refrigerant that flows into the indoor unit 100 flows into the heat exchanger 7 that acts as an evaporator, and cools the indoor air by absorbing heat from it, becoming a low-temperature, low-pressure gas refrigerant. The low-temperature, low-pressure gas refrigerant that flows out of the heat exchanger 7 passes through the gas refrigerant piping 300 and flows into the outdoor unit 200. The refrigerant that flows into the outdoor unit 200 is sucked into the compressor 210 via the flow path switching device 220.

On the other hand, during heating operation, as shown by the dashed line in FIG. 19, the flow path switching device 220 is switched so that the refrigerant discharged from the compressor 210 flows into the heat exchanger 7. Then, the low-temperature, low-pressure refrigerant is compressed by the compressor 210 and discharged as a high-temperature, high-pressure gas refrigerant. The high-temperature, high-pressure gas refrigerant discharged from the compressor 210 flows out of the outdoor unit 200 via the flow path switching device 220, passes through the gas refrigerant piping 300, and flows into the indoor unit 100. The high-temperature, high-pressure gas refrigerant that flows into the indoor unit 100 dissipates heat to the indoor air in the heat exchanger 7 and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant that flows out of the heat exchanger 7 flows out of the indoor unit 100, passes through the liquid refrigerant piping 400, and flows into the outdoor unit 200. The high-pressure liquid refrigerant that flows into the outdoor unit 200 is decompressed to a low-temperature, low-pressure two-phase refrigerant by the throttling device 240, and then flows into the outdoor heat exchanger 230. The low-temperature, low-pressure two-phase refrigerant that flows into the outdoor heat exchanger 230 absorbs heat from the outdoor air and becomes a low-temperature, low-pressure gas refrigerant. The low-temperature, low-pressure gas refrigerant that flows out of the outdoor heat exchanger 230 is sucked into the compressor 210 via the flow switching device 220.

By configuring the air conditioner as described above and switching the flow of refrigerant using the flow path switching device 220 of the outdoor unit 200, cooling operation and heating operation can be achieved.

As described above, the air conditioner according to the fourth embodiment includes the indoor unit 100 and the outdoor unit 200 described in the first to third embodiments.

The air conditioner according to embodiment 4 can achieve the same effects as the indoor unit 100 described in embodiments 1 to 3.

1 rear case, 1a rear, 2 housing, 2a side wall, 3 intake port, 4 exhaust port, 5 front design panel, 7 heat exchanger, 7a outer end, 8 air passage front wall, 8a tongue, 9 air passage rear wall, 11 up and down air direction vanes, 12 left and right air direction vanes, 13 filter, 15 shaft, 16 plate member, 20 first blower, 21 partition plate, 26 first blade, 26i inner peripheral end, 26n negative pressure surface, 26o outer peripheral end, 26p positive pressure surface, 30 second blower, 31 scroll casing, 31a tongue, 31b recess, 31d intake port, 31e exhaust port, 31f inner peripheral end, 32 main plate, 3 2a outer circumferential edge, 33 side plate, 36 second blade, 36a sirocco blade section, 36ar sirocco region, 36b turbo blade section, 36br turbo region, 36i inner circumferential edge, 36i1 leading edge, 36n negative pressure surface, 36p positive pressure surface, 36o outer circumferential edge, 36o1 trailing edge, 41a first suction duct, 41b second suction duct, 42a first outlet duct, 42b second outlet duct, 50 duct partition plate, 51 bell mouth, 100 indoor unit, 200 outdoor unit, 210 compressor, 220 flow path switching device, 230 outdoor heat exchanger, 240 throttling device, 300 gas refrigerant piping, 400 liquid refrigerant piping.

Claims

A housing having an inlet and an outlet formed therein;
A heat exchanger provided inside the housing;
a first blower provided inside the housing on a downstream side of the heat exchanger and configured as a cross-flow fan rotating around a first rotation shaft;
a second fan provided at both ends of the first fan in the first rotation shaft direction and configured as a centrifugal fan rotating around a second rotation shaft;
a scroll casing provided on an outer periphery of the second blower and forming an outlet air passage of the second blower,
The second blower is
A disk-shaped or annular main plate;
an annular side plate arranged opposite the main plate;
a plurality of blades, one end of which is connected to the main plate and the other end of which is connected to the side plate, and which are arranged in a circumferential direction around the second rotation shaft;
Each of the plurality of blades includes:
an inner circumferential end located on the second rotation shaft side in a radial direction centered on the second rotation shaft;
an outer circumferential end located on the outer circumferential side of the inner circumferential end in the radial direction;
a sirocco blade portion including the outer circumferential end and constituting a forward inclined vane having an outlet angle greater than 90 degrees;
a turbo blade portion including the inner circumferential end and constituting a backward-inverted blade.
The first fan includes a plurality of blades arranged in a circumferential direction around the first rotation shaft,
The indoor unit of an air conditioner according to claim 1 , wherein an inlet angle of the blades of the second fan is smaller than an inlet angle of the blades of the first fan.
The plurality of blades of the second fan include
The indoor unit of an air conditioner according to claim 1 or 2, wherein a blade length in a first region closer to the main plate than a middle position in the second rotational shaft direction is longer than a blade length in a second region closer to the side plate than a middle position in the second rotational shaft direction.
The scroll casing has a bell mouth that forms an inlet port for drawing air into the scroll casing,
The indoor unit for an air conditioner according to any one of claims 1 to 3, wherein the bell mouth is provided on an opposite side to the first fan in a direction of the second rotation axis.
The scroll casing has a bell mouth that forms an inlet port for drawing air into the scroll casing,
The indoor unit for an air conditioner according to any one of claims 1 to 3, wherein the bell mouth is provided on a side of the first fan in a direction of the second rotation axis.
The scroll casing has a bell mouth that forms an inlet port for drawing air into the scroll casing,
The indoor unit of an air conditioner according to any one of claims 1 to 3, wherein the bell mouths are provided on a side of the first fan and an opposite side to the first fan in the second rotational axis direction.
a casing provided around an outer periphery of the first fan and forming an outlet air passage of the first fan;
The indoor unit of an air conditioner according to any one of claims 1 to 6, wherein a first distance from a point of the casing closest to the rear surface to the rear surface is shorter than a second distance from a point of the scroll casing closest to the rear surface to the rear surface.
The indoor unit of an air conditioner according to any one of claims 1 to 7, wherein a maximum point of height of the scroll casing in the second rotation axis direction is located between an outer peripheral end and an inner peripheral end of the scroll casing on the heat exchanger side.
The indoor unit of an air conditioner according to any one of claims 1 to 8, wherein a maximum point of height of the scroll casing in the second rotational axis direction is located inside an outer end portion of the heat exchanger in the second rotational axis direction.
In the second rotation axis direction, the main plate and an inner peripheral end of the scroll casing on the main plate side are arranged to coincide with each other or to overlap each other partially,
The indoor unit for an air conditioner according to any one of claims 1 to 9, wherein a gap is formed between an outer circumferential end of the main plate and an inner circumferential end of the scroll casing on the main plate side.
The first blower has a disk-shaped or annular partition plate,
The indoor unit for an air conditioner according to any one of claims 1 to 10, wherein an outer diameter of the partition plate and an outer diameter of the side plate are the same length.
The scroll casing comprises:
The indoor unit of an air conditioner according to any one of claims 1 to 11, further comprising an air duct partition plate that divides an intake air duct extending from the intake port to the upstream side of the first fan and the second fan into a first intake air duct extending from the intake port to the upstream side of the first fan and a second intake air duct extending from the intake port to the upstream side of the second fan.
The indoor unit of an air conditioner according to claim 12, wherein a width of the second intake air duct is equal to or greater than a width of the second outlet air duct.
An air conditioner comprising an indoor unit of the air conditioner according to any one of claims 1 to 13 and an outdoor unit.