WO2023248904A1

WO2023248904A1 - Multi-blade blower and indoor unit

Info

Publication number: WO2023248904A1
Application number: PCT/JP2023/022123
Authority: WO
Inventors: 昭宏近藤
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2022-06-23
Filing date: 2023-06-14
Publication date: 2023-12-28
Also published as: JP2024002259A

Abstract

The present disclosure provides a multi-blade blower capable of reducing miscellaneous vortexes to reduce a variation in the surface pressure of blades and reduce noise.　A scroll casing 2 has a scroll part 4, an intake-side opening 5, and a blowout-side opening 6, wherein: the intake-side opening 5 opens toward the direction of the rotation axis 99 of a Sirocco fan 3 and extends to be tapered toward the inside of the scroll casing 2; and a serration 14 formed by protrusions and recesses is provided to the inner peripheral section of the intake-side opening 5.

Description

Multi-blade blower and indoor unit

The present disclosure relates to a multi-blade blower that rotates to take in a gas-phase fluid flow (hereinafter referred to as an air flow) in the direction of the rotation axis and exhaust it in the radial direction, and an indoor unit equipped with this multi-blade blower.

Patent Document 1 discloses a first protrusion provided on the outer periphery of a fan rotor and extending in the radial direction of the fan rotor, a second protrusion provided on the outer periphery of the fan rotor and extending in the rotation axis direction of the fan rotor, and a second protrusion provided on the housing. , a shielding plate facing the first protrusion from the radial direction of the fan rotor, and a surrounding part provided on the housing and surrounding the tip of the second protrusion, the first protrusion and the shielding plate forming a first labyrinth part. A scirocco fan is disclosed in which a second labyrinth portion is formed by a second protrusion and a surrounding portion.

Japanese Patent Application Publication No. 2014-77381

An object of the present disclosure is to provide a multi-blade blower and an indoor unit that can reduce miscellaneous vortices, reduce fluctuations in blade surface pressure, and reduce noise.

A multi-blade blower of the present disclosure is a multi-blade blower including a scroll casing and a sirocco fan, the scroll casing having a scroll portion, a suction side opening, and an outlet side opening, The suction side opening opens in the direction of the rotation axis of the sirocco fan and extends in a tapered manner toward the inside of the scroll casing, and the inner circumference of the suction side opening is formed with unevenness. Serrations are provided.
This specification includes all contents of Japanese patent application/Japanese Patent Application No. 2022-101348 filed on June 23, 2022.

The multi-blade blower of the present invention can reduce the miscellaneous vortices generated at the outlet of the suction nozzle, thereby reducing fluctuations in the surface pressure of the blades caused by the collision of the miscellaneous vortices with the blades, thereby reducing noise. .

FIG. 1 is a cross-sectional view of an indoor unit in Embodiment 1. FIG. 2 is a longitudinal cross-sectional view of the indoor unit in Embodiment 1. FIG. 3 is a diagram showing a refrigeration cycle circuit in Embodiment 1. FIG. 4 is a perspective view showing a multi-blade blower in Embodiment 1. FIG. 5 is a perspective view showing a multi-blade blower in Embodiment 1. Figure 6 is a conceptual diagram showing the relationship between serrations and longitudinal vortices. Figures 7(a), (b), and (c) are explanatory diagrams showing the relationship between the main flow and the circulation flow. Figure 8 is an explanatory diagram showing the concept of longitudinal vortex formation.

(Findings, etc. that formed the basis of this disclosure)
At the time the inventors came up with the present disclosure, it was possible to reduce ventilation resistance by providing an enlarged air passage, a reduced air passage, and a diverted air passage, each of which is composed of a side plate, a rib, and a sirocco fan, for circulating flow. There is a technology that reduces the circulating flow by increasing the airflow, and reduces the rotational speed at the same air volume to reduce noise.
However, with conventional technology, the speed difference between the main flow and the circulating flow is not alleviated and they merge, resulting in a miscellaneous vortex.The miscellaneous vortex is sucked into the blade, causing the surface pressure of the blade to fluctuate and generate noise. The inventors discovered the problem that the problem occurs, and in order to solve the problem, the subject matter of the present disclosure has been constructed.
The present disclosure provides a multi-blade blower and an indoor unit that can reduce miscellaneous vortices, reduce fluctuations in blade surface pressure, and reduce noise.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of well-known matters or redundant explanations of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art.
The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

(Embodiment 1)
Embodiment 1 will be described below with reference to the drawings.
[1-1. composition]
[1-1-1. Indoor unit configuration]
FIG. 1 is a cross-sectional view of an indoor unit included in an air conditioner. FIG. 2 is a longitudinal sectional view of the indoor unit.
As shown in FIGS. 1 and 2, air conditioner 100 in this embodiment includes a box-shaped housing 101. As shown in FIGS. The housing 101 includes a top plate 102 and a bottom plate 103.
The left side of the housing 101 in FIG. 1 is a ventilation chamber 104, and the right side of the housing 101 in FIG. 1 is a heat exchanger chamber 105 that accommodates the indoor heat exchanger 33. The ventilation chamber 104 and the heat exchanger chamber 105 are separated by a partition wall 106.

A suction side opening 5 for taking in indoor air is provided at the rear of the ventilation chamber 104, and an indoor ventilation device 49 is housed inside the ventilation chamber 104.
Details of the indoor air blower 49 will be described later.

[1-1-2. Refrigeration cycle configuration]
Next, a refrigeration cycle device, which is an example of a device using the multi-blade blower 1 of the present invention, will be explained.
FIG. 3 is a configuration diagram of a refrigeration cycle in an embodiment of the present invention.
In FIG. 3, the refrigeration cycle device 20 includes a main circuit 21, a compressor 31, an outdoor heat exchanger 32, an indoor heat exchanger 33, a four-way valve 40, an outdoor expansion valve 45, and an indoor expansion valve 46. , a refrigerant storage tank 47, an outdoor blower 48, and an indoor blower 49.
The configuration is such that the operation can be switched between radiating heat with the outdoor heat exchanger 32 and absorbing heat with the indoor heat exchanger 33, or absorbing heat with the outdoor heat exchanger 32 and radiating heat with the indoor heat exchanger 33. There is. A device using the refrigeration cycle device 20 for the purpose of heating or cooling air is called an air conditioner or the like, and a device using the refrigeration cycle device 20 for the purpose of heating or cooling water is called a chiller or the like.

Further, as a form of the refrigeration cycle device 20, the outdoor unit 22 includes a compressor 31, an outdoor heat exchanger 32, a four-way valve 40, an outdoor expansion valve 45, a refrigerant storage tank 47, an outdoor blower device 48, and , the indoor unit 23 including the indoor heat exchanger 33, the indoor expansion valve 46, and the indoor blower 49 may be configured as separate units, or the outdoor unit 22 and the indoor unit 23 may be configured as an integrated unit. It may also be configured. Furthermore, even in a configuration in which the outdoor units 22 and indoor units 23 are separated, there are cases where the number of outdoor units 22 and indoor units 23 are the same, and cases where there are more indoor units 23 than outdoor units 22.

In this embodiment, an example of the configuration of an air conditioner in which the outdoor unit 22 and the indoor unit 23 are separated, and there is one outdoor unit 22 and one indoor unit 23, which is often found in home air conditioners and store air conditioners, will be described. show.
When the main circuit 21 performs an operation of dissipating heat with the outdoor heat exchanger 32 and absorbing heat with the indoor heat exchanger 33, the main circuit 21 includes the compressor 31, the first path 41 of the four-way valve 40, the outdoor heat exchanger 32, the outdoor expansion This circuit connects the valve 45, refrigerant storage tank 47, indoor expansion valve 46, and indoor heat exchanger 33 in this order, and returns the heat from the indoor heat exchanger 33 to the compressor 31 via the second path 42 of the four-way valve 40. .
The compressor 31 and the first path 41 of the four-way valve 40 are connected by a flow path 91, the first path 41 of the four-way valve 40 and the outdoor heat exchanger 32 are connected by a flow path 92, and the outdoor heat exchanger 32 and the outdoor expansion valve 45 are connected by a flow path 91. The outdoor expansion valve 45 and the refrigerant storage tank 47 are connected by the path 93, the refrigerant storage tank 47 and the indoor expansion valve 46 are connected by the path 95, the indoor expansion valve 46 and the indoor heat exchanger 33 are connected by the path 96, The indoor heat exchanger 33 and the second path 42 of the four-way valve 40 are connected by a flow path 97, and the second path 42 of the four-way valve 40 and the compressor 31 are connected by a flow path 98.

In addition, when performing an operation of absorbing heat in the outdoor heat exchanger 32 and dissipating heat in the indoor heat exchanger 33, the compressor 31, the third path 43 of the four-way valve 40, the indoor heat exchanger 33, the indoor expansion valve 46, A refrigerant storage tank 47, an outdoor expansion valve 45, and an outdoor heat exchanger 32 are connected in this order, and the circuit returns from the outdoor heat exchanger 32 to the compressor 31 via the fourth path 44 of the four-way valve 40.

The compressor 31 and the third path 43 of the four-way valve 40 are connected by a flow path 91, the third path 43 of the four-way valve 40 and the indoor heat exchanger 33 are connected by a flow path 97, and the indoor heat exchanger 33 and the indoor expansion valve 46 are connected by a flow path 97. The indoor expansion valve 46 and the refrigerant storage tank 47 are connected by the path 96, the refrigerant storage tank 47 and the outdoor expansion valve 45 are connected by the path 94, the outdoor expansion valve 45 and the outdoor heat exchanger 32 are connected by the path 93, The outdoor heat exchanger 32 and the fourth path 44 of the four-way valve 40 are connected by a flow path 92, and the fourth path 44 of the four-way valve 40 and the compressor 31 are connected by a flow path 98. Switching of the main circuit 21 depending on the operation of the refrigeration cycle device 20 is performed by a four-way valve 40. Inside the main circuit 21, a refrigerant such as R32 or R410A and compressor oil for lubricating the sliding parts of the compressor 31 are sealed.

The compressor 31 is a rotary compressor, that is, a cylinder having a cylindrical internal space, a rotor arranged eccentrically with respect to the central axis inside the cylinder, and a rotor that is slidably housed in a slit provided in the cylinder wall. The cylinder is equipped with a gate valve whose tip is always in contact with the cylindrical surface of the rotor, and communication holes to the main circuit 21 on both sides of the gate valve in the cylinder.
The outdoor heat exchanger 32 and the indoor heat exchanger 33 are fin-and-tube heat exchangers, that is, an aluminum plate with a thickness of about 0.1 mm with a plurality of round holes with a diameter of about 5 mm to 8 mm. It consists of fins with round holes bent into a collar shape and copper or aluminum tubes.Hundreds of fins are lined up, the tubes are inserted into the round holes, and the tubes are pushed apart so that they fit tightly against the fins. ing.

The four-way valve 40 is configured to be able to switch between a combination of the first path 41 and the second path 42 or the third path 43 and the fourth path 44 using an internal valve.
The outdoor expansion valve 45 and the indoor expansion valve are configured to partially make it difficult for the refrigerant to flow by reducing the cross-sectional area of the path through which the refrigerant flows with respect to the main circuit 21, or by switching between closing and opening.
The refrigerant storage tank 47 includes a container and two communication holes for connection to the main circuit 21, and a pipe extends from the communication hole to the lower part inside the container, and mainly stores the liquid phase refrigerant accumulated in the lower part of the container. It is configured to return to the circuit 21.

The outdoor blower device 48 uses an axial blower or a mixed flow blower.
A duct indoor unit is used as the indoor unit 23. The indoor unit 23 includes a housing 30, an indoor heat exchanger 33, an indoor expansion valve 46, an electric motor 89, and an indoor air blower 49.
The casing 30 is provided with a communication hole therein which passes through the indoor air blower 49 and the indoor heat exchanger 33 in this order, and whose both ends are open to the indoor atmosphere.
The electric motor 89 uses a variable speed DC inverter motor.
The indoor heat exchanger 33 uses a fin-and-tube type. The indoor heat exchanger 33 surrounds the indoor blower device 49 with a predetermined gap, and although it has ventilation resistance, airflow can pass therethrough.

[1-1-3. Configuration of indoor air blower]
Next, the indoor air blower will be explained.
FIG. 4 is a perspective view of a multi-blade blower. FIG. 5 is a perspective view of a multi-blade blower.
As shown in FIGS. 4 and 5, the indoor blower device 49 includes a multi-blade blower 1 and an electric motor 89. The multi-blade blower 1 includes a scroll casing 2 and a sirocco fan 3.
The scroll casing 2 includes a scroll portion 4, a suction side opening 5, an outlet side opening 6, and a tongue portion 7, and is fixed to a housing 30.

The radius of the scroll portion 4 increases in a spiral manner toward the front in the direction of rotation of the sirocco fan 3. Specifically, the expansion rate of the Archimedes curve is used. The suction side opening 5 is open in the axial direction of the rotating shaft 99 and has a suction side opening 5 that contracts toward the inside of the scroll casing 2 at a predetermined curvature.
The blow-off side opening 6 opens at the outer peripheral end of the scroll portion 4 . The suction side opening 5 and the blowout side opening 6 communicate with each other and form a ventilation path. The tongue portion 7 connects the outlet opening 6 and the inner circumferential end of the scroll portion 4, has an acute angle, and has its ridgeline rounded to a radius of about 10 mm.

The sirocco fan 3 includes a main plate 10, a plurality of blades 11, and an end ring 12. The main plate 10 is a disk concentric with the rotating shaft 99 and is fixed to the rotating shaft 99 of the electric motor 89 .
The blade 11 has a blade shape that is inclined so that the rear side in the direction of rotation of the sirocco fan 3 approaches the rotation axis 99, and extends from the main plate 10 in parallel to the rotation axis 99. The number of blades of the sirocco fan 3 is 40, which are arranged at equal intervals around the rotating shaft 99. The end ring 12 is a circular ring, and connects the wings 11 at the end of the wings 11 on the opposite side to the main plate 10. The wings 11 extend on both sides of the main plate 10. There is a gap of about 10 mm between the scroll casing 2 and the sirocco fan 3, and the sirocco fan 3 can be rotated by an electric motor 89. The scroll casing 2 and sirocco fan 3 of the multi-blade blower are manufactured by resin molding.

The suction side opening 5 is rounded with a radius of about 10 mm to 50 mm so as to be convex toward the main flow 17 side.
In this embodiment, serrations 14 are provided on the inner periphery of the suction side opening 5, and are formed of approximately triangular irregularities.
In the serrations 14, the angle of the outlet of the suction side opening 5 is inclined toward the rotation axis 99 by 3 degrees or more and 30 degrees or less with respect to the rotation axis 99. Furthermore, the serrations 14 are formed so that W/H is 0.3 or more and 5.0 or less, where H is the depth and W is the width of one recess.

{1-2. Effect]
The operation and effects of the refrigeration cycle device 20 and the multi-blade blower 1 configured as described above will be explained below.
When the refrigeration cycle device 20 performs an operation in which the outdoor heat exchanger 32 radiates heat and the indoor heat exchanger 33 absorbs heat, the refrigerant sealed in the main circuit 21 is compressed in a low-temperature, low-pressure gas phase state. It is sucked into the machine 31 and compressed by the compressor 31 into a high temperature and high pressure gaseous state. The flow direction of the refrigerant is selected by the four-way valve 40, and the refrigerant flows to the outdoor heat exchanger 32. The refrigerant radiates heat by the outdoor heat exchanger 32, and becomes a medium-temperature, medium-pressure liquid phase state. After the refrigerant is stored in the refrigerant storage tank 47, the flow rate of the refrigerant is adjusted by the indoor expansion valve 46, and the refrigerant is discharged.The refrigerant absorbs heat from the outside air in the indoor heat exchanger 33, evaporates, and is in a low-temperature, low-pressure gas phase state. , and is again compressed by the compressor 31 into a high-temperature, high-pressure gaseous state.
This series of operations moves indoor heat to the outdoors via the refrigerant, resulting in a cooling operation in the air conditioner.

In addition, when the refrigeration cycle device 20 operates to absorb heat in the outdoor heat exchanger 32 and radiate heat in the indoor heat exchanger 33, in the main circuit 21, the refrigerant sealed in the main circuit 21 is in a low-temperature, low-pressure gas phase. The gas is sucked into the compressor 31 in this state, and is compressed by the compressor 31 into a high temperature and high pressure gas phase state. The flow direction of the refrigerant is selected by the four-way valve 40, and the refrigerant flows to the indoor heat exchanger 33, where it radiates heat and becomes a medium-temperature, medium-pressure liquid phase refrigerant. After the refrigerant is stored in the refrigerant storage tank 47, the flow rate of the refrigerant is adjusted by the outdoor expansion valve 45 and then discharged.The refrigerant radiates heat to the outside air and evaporates in the outdoor heat exchanger 32, and is in a low-temperature, low-pressure gas phase state. , and is again compressed by the compressor 31 into a high-temperature, high-pressure gaseous state.
This series of operations moves outdoor heat into the room via the refrigerant, resulting in a heating operation in the air conditioner.
In particular, when the indoor heat exchanger 33 radiates or absorbs heat, the multi-blade blower 1 is used to generate airflow to improve heat exchange efficiency and circulate temperature-controlled air indoors.

The airflow generated by the multi-blade blower 1 is taken in from the suction side opening 5 of the scroll casing 2 at the room temperature, flows through the scroll part 4 while being pressurized by the sirocco fan 3, and then flows from the blowout side opening 6 at the room temperature. It will be exhausted. Thereafter, it passes through the indoor heat exchanger 33, where it exchanges heat with the refrigerant, is cooled during cooling operation, warmed during heating operation, and is blown out from the casing 30.

In FIG. 4, the scroll casing 2 and the electric motor 89 are fixed to a housing 30 (not shown), and the sirocco fan 3 is rotationally driven by the electric motor 89. The airflow is sucked in from the suction side opening 5 in the axial direction of the rotating shaft 99, passes through the blades 11, is pressurized while swirling around the scroll portion 4, and is blown out from the blowout side opening 6.

On the other hand, as can be seen from the fact that the airflow flows from the high pressure side to the low pressure side and that the airflow is sucked in from the suction side opening 5 and blown out from the blowout side opening 6, the inside of the blade 11 is surrounded by air. The pressure is low in some areas, and the pressure outside is high. That is, the pressure inside the scroll casing 2 located on the outside is higher than that in the suction side opening 5 located on the inside of the blade 11 .
Therefore, as shown in FIG. 5, a circulation flow 18, which is an airflow leaking from the scroll portion 4 toward the suction side opening 5, is generated.

FIG. 6 is a conceptual diagram showing the relationship between serrations and longitudinal vortices.
If the circulating flow 18 merges with the main flow 17 without its velocity being relaxed, a miscellaneous vortex is generated. As shown in FIG. 6, there are many vortices disturbed by the blades 11 around the blades 11, but it can also be seen that relatively strong miscellaneous vortices are generated downstream of the suction side opening 5.
The circumferential rotation speed of the blades 11 is, for example, 10 m/sec to 20 m/sec, whereas the wind speed of the suction airflow is as slow as several m/sec. It cannot pass through the gap between the blades 11 and is cut by the plurality of blades 11.
Since the internal pressure of the miscellaneous vortex is reduced due to centrifugal force, the surface pressure of the blade 11 is the same as that of the surroundings before cutting the miscellaneous vortex, decreases when cutting the miscellaneous vortex, and the surface pressure of the blade 11 decreases when the miscellaneous vortex is cut. Then it will recover. That is, the surface pressure of the blade 11 oscillates. Since pressure vibrations are sound waves themselves, noise is generated.

On the other hand, by slanting the outlet of the suction side opening 5 toward the rotating shaft 99 and providing the serrations 14 on the end face of the outlet of the suction side opening 5, the main flow 17 has a serration inflow angle with respect to the serrations 14. 15, and a longitudinal vortex 19 is generated that flows in the direction of the main flow 17 but has a rotational component in a plane perpendicular to the direction of the main flow 17. The longitudinal vortex 19 is a structural vortex whose strength and direction are relatively stable, unlike miscellaneous vortices whose direction and size are not fixed.

Next, the concept of mixing airflows having different speeds by the serrations 14 will be explained.
The serrations 14 have a function of generating a longitudinal vortex swirling on a plane perpendicular to the direction of travel of the airflow when the airflow begins to leak from the concave portion thereof.
Therefore, it is effective in cases where the serrations 14 have an angle that slightly blocks the airflow, or in cases where there is a pressure difference on both sides of the plate having the serrations 14 and a curling flow occurs. On the other hand, if there is no pressure difference on both sides of the plate and the flow is parallel, the serration effect cannot be obtained.

FIGS. 7(a), (b), and (c) are explanatory diagrams showing the relationship between the main flow and the circulating flow.
Here, in FIG. 7(a), if the suction nozzle outlet 13 does not have the serrations 14 and does not taper toward the rotating shaft 99, the directions of the main flow and the circulation flow are parallel at the confluence of the main flow and the circulation flow. Since the velocity gradient between these airflows is large, a vortex is generated downstream of the suction nozzle outlet 13, as shown in FIG. As a result, the vortex is sucked into the sirocco fan 3 and collides with the blade 11, causing fluctuations in the surface pressure of the blade 11, resulting in NZ sound having a peak at a frequency of (number of blades x rotation speed), Noise increases.

Furthermore, as shown in FIG. 7(b), if the suction nozzle outlet 13 does not have the serrations 14 and tapers toward the rotating shaft 99, the circulating flow flows along the slope of the suction nozzle outlet 13. , the velocity gradient plus the element of airflow collision creates a larger vortex.
Furthermore, as shown in FIG. 7(c), if the suction nozzle outlet 13 has serrations 14 and does not taper toward the rotation axis 99, the serrations 14 may be arranged diagonally with respect to the direction of movement of the airflow. While the effect is obtained when the airflow is parallel to the airflow, the effect of the serrations 14 is not obtained because it is parallel to the airflow and is equivalent to the case without the serrations 14, and a vortex is generated.

In contrast, in the multi-blade blower of the present embodiment, the serrations 14 are provided at the suction nozzle outlet 13 and tapered toward the rotating shaft 99, so that the suction nozzle outlet 13 is disposed diagonally with respect to the main flow. As a result, velocity gradients are relaxed and vortices are reduced. Since vortices are reduced, noise is reduced.

FIG. 8 is an explanatory diagram showing the concept of forming a longitudinal vortex.
As shown in FIG. 8, when the airflow hits the suction side opening 5 at an angle with respect to the serrations 14, the airflow leaks from the concave portions of the serrations 14 in the direction of travel, causing continuous leakage. Like a screw thread, it has a structure that has both a forward direction component and a rotation direction component.
In the multi-blade blower 1 of the present disclosure, the angle of the outlet of the suction side opening has an inclination of 3 degrees or more and 30 degrees or less with respect to the rotation axis, and the outlet side of the suction side opening The end face of one recess is provided with serrations where the depth is H and the width is W, W/H is 0.3 or more and 5.0 or less, and H and W are both greater than or equal to the plate thickness of the suction side opening.
As a result, the main flow 17 flows into the serrations 14 with a serration inflow angle 15, and a longitudinal vortex 19 is generated between the main flow 17 and the circulation flow 18 by the concave portions of the serrations to mix the respective air flows. Velocity gradient is relaxed and miscellaneous vortices are reduced.

[1-3. Effects, etc.]
As described above, in the present embodiment, the scroll casing 2 has the scroll portion 4, the suction side opening 5, and the blowout side opening 6, and the suction side opening 5 has the sirocco fan. The suction side opening 5 is opened in the direction of the rotating shaft 99 of the scroll casing 2 and extends in a tapered manner toward the inside of the scroll casing 2. The inner circumferential portion of the suction side opening 5 is provided with serrations 14 formed with unevenness.
As a result, miscellaneous vortices can be reduced at the outlet of the suction side opening 5, so that fluctuations in the surface pressure of the blades 11 can be reduced, and the noise of the multi-blade blower 1 can be reduced.

Further, in this embodiment, the unevenness is formed of triangular unevenness.
As a result, the serrations 14 formed into triangular irregularities can reduce miscellaneous vortices at the outlet of the suction side opening 5, thereby reducing fluctuations in the surface pressure of the blades 11 and reducing the noise of the multi-blade blower 1. can.

Further, in this embodiment, when the depth of one recess is H and the width is W, W/H of the serrations 14 is 0.3 or more and 5.0 or less, and both H and W are on the suction side. It is formed to be thicker than the plate thickness of the opening.
As a result, the main flow 17 flows into the serrations 14 with a serration inflow angle 15, and a longitudinal vortex 19 is generated between the main flow 17 and the circulation flow 18 by the concave portions of the serrations to mix the respective air flows. The velocity gradient is relaxed and miscellaneous vortices can be reduced.

(Other embodiments)
As mentioned above, Embodiment 1 has been described as an example of the technology disclosed in this application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments in which changes, replacements, additions, omissions, etc. are made.
Therefore, other embodiments will be illustrated below.
The compression type of the compressor 31 may be a rotary type, a scroll type, a reciprocating type, or a turbo type. Further, the compressor 31 may be powered by an electric motor provided inside the compressor 31, an electric motor independent of the compressor 31, or a prime mover instead of the electric motor. As long as it is a mechanism that can compress gas phase refrigerant, its type and power do not matter.

In addition, the indoor unit 23 may be a chiller module that adjusts the temperature of water instead of adjusting the temperature of indoor air, and may be integrated into a chemical substance fractionation facility, etc., instead of being a separate housing. It's okay if it is. As long as the configuration allows heat exchange from the main circuit 21 to the outside, the object or form of temperature adjustment is not limited.
In addition, even if the indoor heat exchanger 33 is a heat exchanger in the form of a series of flat tubes, the refrigerant side is called a microchannel heat exchanger, which integrates multiple fine channels, and the air side is composed of a collection of fins. It may also be a heat exchanger in the form of Any type of structure may be used as long as it allows the airflow generated by the indoor air blower 49 to pass through and exchanges heat.

Further, the electric motor 89 may be a constant speed DC motor or an AC motor, or may be not limited to an electric motor but may be any other rotary drive device. Any type may be used as long as the indoor air blower 49 can be rotated.
Further, the refrigerant sealed in the main circuit 21 may be CO2 or the like that does not undergo a phase change, and the type of refrigerant is not limited.
Further, the suction side opening 5 may be in the shape of a nozzle facing the inside of the scroll casing 2, or may be a simple round hole.

Further, although the multi-blade blower 1 is manufactured by resin molding in the present invention, it may be partially or entirely made of sheet metal, cast metal, or machined.
In addition, other curves such as an involute curve may be used in addition to the Archimedean curve for the scroll portion 4, but since changes in the air flow due to the shape of the scroll portion 4 have little effect on the air flow colliding with the tongue portion 7, unevenness may be used. If part 16 is applied, there is a noise reduction effect.

Moreover, the number of blades of the sirocco fan 3 may be any number. Generally, there are about 30 to 50 sheets. The blades 11 do not necessarily have to extend parallel to the rotation axis 99. In terms of production, it is often used to use a uniaxial mold because it is low cost, and the blades 11 are often made parallel to the rotation axis 99 in order to be able to take out the mold from the mold even with a single axis. A three-dimensional blade shape may be formed by using a core or by performing post-forming processing such as welding or welding. Furthermore, if deformation is not a problem in practice, such as when the blade 11 extends for a short length, the end ring may be omitted.

(Additional note)
The following techniques are disclosed by the description of the above embodiments.
(Technology 1) A multi-blade blower including a scroll casing and a sirocco fan, the scroll casing having a scroll portion, a suction side opening, an outlet side opening, and a tongue, The suction side opening opens in the direction of the rotation axis of the sirocco fan and extends in a tapered manner toward the inside of the scroll casing, and the inner circumference of the suction side opening is formed with unevenness. A multi-blade blower with serrations.
With this configuration, it is possible to reduce miscellaneous vortices at the outlet of the suction side opening, thereby reducing fluctuations in the surface pressure of the blade. Therefore, the noise of the multi-blade blower can be reduced.

(Technique 2) The multi-blade blower according to Technique 1, wherein the unevenness is formed of triangular unevenness.
With this configuration, the serrations formed in triangular irregularities can reduce the miscellaneous vortices at the outlet of the suction side opening, so that fluctuations in the surface pressure of the blade can be reduced. Therefore, the noise of the multi-blade blower can be reduced.

(Technology 3) In the serrations, where the depth of one recess is H and the width is W, W/H is 0.3 or more and 5.0 or less, and H and W are both greater than or equal to the thickness of the suction side opening. The multi-blade blower according to technology 1 or technology 2, which is formed in.
With this configuration, the main flow flows into the serrations with a serration inflow angle, and a longitudinal vortex is generated between the main flow and the circulation flow by the recesses of the serrations, thereby mixing the respective air flows. Therefore, the velocity gradient is relaxed and miscellaneous vortices can be reduced.

(Technology 4) An indoor unit comprising the multi-blade blower according to any one of Techniques 1 to 3, and an indoor heat exchanger disposed opposite to the outlet opening.
With this configuration, it is possible to reduce miscellaneous vortices at the outlet of the suction side opening, thereby reducing fluctuations in the surface pressure of the blade. Therefore, it is possible to obtain an indoor unit that can reduce the noise of the multi-blade blower.

As described above, since the multi-blade blower according to the present invention can reduce noise, it can be used not only in refrigeration cycle devices such as air conditioners and chillers, but also in air handling devices such as circulators and duct blowing equipment, ventilation devices, and fan heaters. It can be applied to all equipment using multi-blade blowers, such as intake and exhaust systems for combustors such as combustors, airflow circulation systems for biobenches, etc.

1 Multi-blade blower 2 Scroll casing 3 Sirocco fan 4 Scroll portion 5 Suction side opening 6 Outlet side opening 7 Tongue portion 8 Start side end portion 9 End side end portion 10 Main plate 11 Wing 12 End ring 13 Step 14 Linear sound source portion 15 Point sound source section 16 Uneven part 17 Uneven height 18 Uneven crest width 19 Uneven length 20 Refrigeration cycle device 21 Main circuit 22 Outdoor unit 23 Indoor unit 30 Housing 31 Compressor 32 Outdoor heat exchanger 33 Indoor heat exchanger 40 Four-way valve 41 First path of four-way valve 42 Second path of four-way valve 43 Third path of four-way valve 44 Fourth path of four-way valve 45 Outdoor expansion valve 46 Indoor expansion valve 47 Refrigerant storage tank 48 Outdoor blower device 49 Indoor blower device 89 Electric motor 91 to 98 Flow path 99 Rotating shaft 101 Housing 102 Top plate 103 Bottom plate 104 Ventilation chamber 105 Heat exchanger chamber 106 Partition wall

Claims

A multi-blade blower comprising a scroll casing and a sirocco fan,
The scroll casing has a scroll portion, a suction side opening, an outlet side opening, and a tongue portion,
The suction side opening opens in the direction of the rotation axis of the sirocco fan and extends in a tapered manner toward the inside of the scroll casing,
The multi-blade blower is provided with serrations formed of unevenness on the inner circumference of the suction side opening.
The multi-blade blower according to claim 1, wherein the unevenness is formed of triangular unevenness.
The serrations are formed such that when the depth of one recess is H and the width is W, W/H is 0.3 or more and 5.0 or less, and both H and W are larger than the thickness of the suction side opening. The multi-blade blower according to claim 1 or 2.
The multi-blade blower according to claim 1;
An indoor unit equipped with an indoor heat exchanger placed opposite the outlet opening.