Patent Grant
10648681
This application is a U.S. national stage application of PCT/JP2016/071189 filed on Jul. 19, 2016, the contents of which are incorporated herein by reference.
The present invention relates to a heat source unit including a fan having a bellmouth, and to a refrigeration cycle apparatus including the heat source unit.
For an air-conditioning apparatus as an example of a refrigeration cycle apparatus, studies have hitherto been conducted to improve air-sending performance of an outdoor unit being a heat source unit. As one of the air-conditioning apparatuses described above, for example, an air-conditioning apparatus disclosed in Patent Literature 1 is known, Patent Literature 1 discloses an outdoor unit including a fan, a heat exchanger, and a partition plate. The heat exchanger is arranged behind the fan. The partition plate is arranged in front of the fan, and is configured to separate a part closer to an air inlet and a part closer to an air outlet. The partition plate has a first orifice having a substantially cylindrical shape and a second orifice having a conical shape. The first orifice is formed so as to surround an outer periphery of a rear end portion of the fan and project to the air inlet, and has a distal end portion formed as an open end toward the air outlet. The second orifice is concentric with the first orifice to expand toward the air outlet, and is provided so as to continue to an outer side of the first orifice.
According to the configuration disclosed in Patent Literature 1, the following effects can be obtained. Specifically, when the second orifice is formed in a slope of a conical shape, or two levels of slopes of a conical shape are formed in the second orifice, release from the second orifice can be prevented for a large air volume. Further, when a portion of the slope of a conical shape has a flat surface facing the first orifice, flow of air can be smoothed to increase an air volume and reduce noise.
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2011-179778
In the outdoor unit of the air-conditioning apparatus disclosed in Patent Literature 1, however, a downstream side of a straight tubular portion that surrounds the fan is open. Therefore, flow of air that is blown off becomes turbulent. As a result, the air collides against an air outlet grille to increase noise. In addition, a bellmouth is generally formed of a metal plate. Therefore, it is difficult to form an air outlet portion in addition to the air inlet portion as disclosed in Patent Literature 1 on a single bellmouth.
The present invention has been made in view of the problems described above as a background, and an object thereof is to provide a heat source unit and a refrigeration cycle apparatus, which are improved in air-sending performance to reduce noise.
According to one embodiment of the present invention, there is provided a heat source unit, comprising: an axial-flow fan: and a bellmouth surrounding an outer periphery of the axial-flow fan, wherein the bellmouth includes: a straight tubular portion having a cylindrical shape; an air inlet portion, which is positioned on an upstream side of the straight tubular portion, and is radially expanded toward the upstream side; and an air outlet portion, which is positioned on a downstream side of the straight tubular portion, and is radially expanded toward the downstream side, and wherein, in sectional view of the air inlet portion of the bellmouth taken along a direction parallel to flow of an air, the air inlet portion has at least one angle-reduced portion that satisfies θ0>θi>0, where, an angle formed by a line L1 and a line L2 is taken as θ0, and an angle formed by a straight line L3 and the line L2 is taken as θi, the line L1 is a line passing through a portion of an outer peripheral end portion of the air inlet portion, which has a maximum diameter, and running in parallel to an axial direction of the axial-flow fan, the line L2 is a line passing through a connecting portion between the air inlet portion and the straight tubular portion and running in a direction orthogonal to the axial direction of the axial-flow fan, and the straight line L3 is a line connecting an intersection P of the line L1 and the line L2 and a portion of the outer peripheral end portion of the air inlet portion, which has a diameter smaller than the maximum diameter and larger than a minimum diameter.
According to one embodiment of the present invention, there is provided a refrigeration cycle apparatus, including: the heat source unit described above; and a load-side unit to be connected to the heat source unit.
According to the heat source unit of one embodiment of the present invention, the angle-reduced portion is formed on at least a part of the air inlet portion of the bellmouth. Therefore, the air flowing into the casing can be made to flow along the air inlet portion. Thus, release of the air can be suppressed, and hence noise reduction can also be achieved.
The refrigeration cycle apparatus of one embodiment of the present invention includes the heat source unit described above. Therefore, the air flowing into the heat source unit can be made to flow along the air inlet portion of the bellmouth. Thus, the release of the air can be suppressed, and hence generation of the noise is reduced.
Now, embodiments of the present invention are described with reference to the drawings as appropriate. Note that, the relationships between the sizes of components in the following drawings including
<Configuration of Heat Source Unit 50A>
The heat source unit 50A is used as an outdoor unit as one configuration included in a refrigeration cycle apparatus such as an air-conditioning apparatus. Specifically, the heat source unit 50A is connected to a load-side unit (indoor unit; not shown) to construct a refrigeration cycle apparatus such as an air-conditioning apparatus. The air-conditioning apparatus as an example of the refrigeration cycle apparatus is described in Embodiment 5.
As illustrated in
The casing 1 has air inlets formed in at least two surfaces (for example, a side surface and a rear surface) and is formed in a box shape. Further, a partition wall 11 illustrated in
The heat exchanger 2 is disposed at a position corresponding to the air inlets of the casing 1. For example, when the air inlet is formed in the side surface and the rear surface or the casing 1, the heat exchanger 2 may be formed to have an L-shape in top view so as to correspond to the air inlet formed in the side surface and the back surface of the casing 1.
A front panel 8 is provided on a front surface side of the casing 1 (on a side surface side of the heat exchanger illustrated in
The axial-flow fan 4 is driven to rotate by a fan motor 3 installed inside the casing 1. The fan motor 3 and the axial-flow fan 4 are coaxially coupled to each other.
Further, the axial-flow fan 4 is surrounded by a bellmouth 30. Specifically, the bellmouth 30 is provided so as to surround an outer periphery of the axial-flow fan 4.
The bellmouth 30 includes a straight tubular portion 5 having a cylindrical shape, an air inlet portion 6 having an arc-shaped cross section, and an air outlet portion 7 having an arc-shaped cross section. The air inlet portion 6 is on an upstream side of the straight tubular portion 5, and is radially expanded toward the upstream side. The air outlet portion 7 is on a downstream side of the straight tubular portion 5, and is radially expanded toward the downstream side. The straight tubular portion 5 has a cylindrical shape with a constant diameter and is positioned in the center in an axial direction of the bellmouth 30. The air inlet portion 6 is positioned on the upstream side of the straight tubular portion 5, specifically, closer to an air inlet of the bellmouth 30. The air outlet portion 7 is positioned on the downstream side of the straight tubular portion 5, specifically, closer to an air outlet of the bellmouth 30. The sectional shapes of the air inlet portion 6 and the air outlet portion 7 are not required to have perfect arc shapes.
The air inlet portion 6 will be described in detail.
As illustrated in
Next, as illustrated in
In this case, the air inlet portion 6 is formed so as to have at least one angle-reduced portion 10 that satisfies θ0>θi>0. The angle-reduced portion 10 is a portion which has an angle reduced to be smaller than the angle θ0 based on the angle θ0 as a reference and has a width in a circumferential direction of the bellmouth 30, as illustrated in
<Operation and Effects of Heat Source Unit 50A>
After the heat source unit 50A starts operating, a controller (not shown) drives the fan motor 3 so that the axial-flow fan 4 is driven to rotate. By the rotation of the axial-flow fan 4, an air inlet flow is generated on the heat exchanger 2 side. Then, an air outside the heat source unit 50A is sucked into the heat source unit 50A. More specifically, the air outside the heat source unit 50A flows into the heat source unit 50A from the left side of a drawing sheet of
In the related-art heat source unit 50X, as illustrated in
Therefore, the air flowing into the heat source unit 50X is not guided from a heat exchanger 2X directly into the axial-flow fan 4X and collides with the back surface of the front panel 8X to concentrate on the back surface of the front panel 8X and the outer wall of the bellmouth 30X to increase an air velocity.
While being increased in air velocity, the flow of the air deviates in the end portion 9X on an upstream side of the air inlet portion 6X of the bellmouth 30X. The deviated flow of the air is directed to a side opposite to an axial center of the axial-flow fan 4X, specifically, becomes a backflow. Therefore, the flow, which is to be sucked into the axial-flow fan 4X to flow along the air inlet side of the bellmouth 30X, is pushed back by the backflow. As a result, an air volume is decreased. Further, the air does not flow along the air inlet side of the bellmouth 30X to generate release of the flow and become an airflow resistance.
An angle of the flow of the air at the time of deviation is determined by the angle θ0 of the air inlet portion 6X, and the air flows in a tangential direction of the end portion 9X on the upstream side of the air inlet portion 6X. For example, when θ0 is 90 degrees and an angle of the flow of the air is θv, the air deviates at 0 degrees. The angle θv becomes 0 degrees when the flow of the air is parallel to the front panel 8X.
In contrast, in the heat source unit 50A, the air inlet portion 6 has the angle-reduced portion 10 that satisfies θ0>θi>0. Therefore, as illustrated in
Further, as illustrated in
<Modification Example of Bellmouth 30>
As illustrated in
As illustrated in
In the heat source unit 50B according to Embodiment 2, the air inlet portion 6 of the bellmouth 30 is formed so that the angle-reduced portion 10 is positioned closer to the heat exchanger 12, or closer to the partition wall 11, or both.
Meanwhile, in the related-art heat source unit 50X, the flow of the air in the heat exchanger 12X, which is sucked from the vicinity of the front panel 8X, moves directly toward the outer wall of the bellmouth 30X as illustrated in
In contrast, in the heat source unit 50B, the angle-reduced portion 10 is formed on the air inlet portion 6 of the bellmouth 30. Further, the angle-reduced portion 10 is positioned closer to the heat exchanger 12, or closer to the partition wall 11, or both. In this manner, as illustrated in
As illustrated in
As illustrated in
In contrast, in the heat source unit 50C, the air inlet portion 6 of the bellmouth 30 is formed larger than the blade edge vortices (indicated by the arrows 14 in
As illustrated in
As described in Embodiment 3, the blade edge vortices (indicated by the arrows 14X in
When the air outlet portion 7X satisfies Ro/Df>0.05 as illustrated in
In contrast, in the heat source unit 50D according to Embodiment 4, the air outlet portion 7 is formed so as to satisfy Ro/Df<0.05. Therefore, as illustrated in
The air-conditioning apparatus 100 is an example of the refrigeration cycle apparatus, and includes an outdoor unit 100A and an indoor unit 100B.
The outdoor unit 100A accommodates the compressor 101, a flow switching device 102, an expansion device 104, a second heat exchanger 105, and an air-sending device 107 provided to the second heat exchanger 105. The air-conditioning apparatus 100 includes the heat source unit according to any one of Embodiment 1 to Embodiment 4 as the outdoor unit 100A.
The heat source unit 100B accommodates a first heat exchanger 103 and the air-sending device 107 provided to the first heat exchanger 103.
As illustrated in
The compressor 101 is configured to compress the refrigerant. The refrigerant compressed by the compressor 101 is discharged to be sent to the first heat exchanger 103. The compressor 101 may be formed of, for example, a rotary compressor, a scroll compressor, a screw compressor, a reciprocating compressor, or other compressors.
The flow switching device 102 is configured to switch the flow of the refrigerant between the heating operation and the cooling operation. Specifically, the flow switching device 102 is switched so as to connect the compressor 101 and the first heat exchanger 103 during the heating operation and is switched so as to connect the compressor 101 and the second heat exchanger 105 during the cooling operation. The flow switching device 102 may preferably be formed of a four-way valve. A combination of two-way valves or three-way valves may be adopted as the flow switching device 102.
The first heat exchanger 103 functions as a condenser during the heating operation and functions as an evaporator during the cooling operation. Specifically, when functioning as the condenser, the first heat exchanger 103 exchanges heat between high-temperature and high-pressure refrigerant discharged from the compressor 101 and an air supplied by the air-sending device 107 to condense high-temperature and high-pressure gas refrigerant. Meanwhile, when functioning as the evaporator, the first heat exchanger 103 exchanges heat between low-temperature and low-pressure refrigerant flowing out of the expansion device 104 and the air supplied by the air-sending device 107 to evaporate low-temperature and low-pressure liquid refrigerant or two-phase refrigerant.
The expansion device 104 is configured to expand the refrigerant flowing out of the first heat exchanger 103 or the second heat exchanger 105 to decompress the refrigerant. The expansion device 104 may preferably be formed of, for example, an electric expansion valve capable of controlling a flow rate of the refrigerant, or other devices. As the expansion device 104, not only the electric expansion valve but also a mechanical expansion valve using a diaphragm for a pressure-receiving portion, a capillary tube, or other devices can be used.
The second heat exchanger 105 functions as an evaporator during the heating operation and functions as a condenser during the cooling operation. Specifically, when functioning as the evaporator, the second heat exchanger 105 exchanges heat between low-temperature and low-pressure refrigerant flowing out of the expansion device 104 and an air supplied by the air-sending device 107 to evaporate low-temperature and low-pressure liquid refrigerant or two-phase refrigerant. Meanwhile, when functioning as the condenser, the second heat exchanger 105 exchanges heat between high-temperature and high-pressure refrigerant discharged from the compressor 101 and the air supplied by the air-sending device 107 to condense high-temperature and high-pressure gas refrigerant.
The air-conditioning apparatus 100 includes the heat source unit according to any one of Embodiment 1 to Embodiment 4. Therefore, the second heat exchanger 105 corresponds to the heat exchanger 2 included in the heat source unit according to any one of Embodiment 1 to Embodiment 4. Similarly, the air-sending device 107 configured to supply the air to the second heat exchanger 105 corresponds to the axial-flow fan 4 included in the heat source units according to Embodiment 1 to Embodiment 4, and the air-sending device motor 108 corresponds to the fan motor 3 included in the heat source units according to Embodiment 1 to Embodiment 4.
<Operation of Air-Conditioning Apparatus 100>
An operation of the air-conditioning apparatus 100 is now described together with flow of the refrigerant. In this case, the operation of the air-conditioning apparatus 100 is described, taking as an example a case in which a heat exchanging fluid is an air and a heat exchanged fluid is refrigerant.
First, the cooling operation performed by the air-conditioning apparatus 100 is described. The flow of the refrigerant during the cooling operation is indicated by the broken arrows in
As illustrated in
The high-pressure liquid refrigerant fed from the second heat exchanger 105 turns into refrigerant in a two-phase state, that is, gas refrigerant and liquid refrigerant at a low pressure, through the expansion device 104. The refrigerant in the two-phase state flows into the first heat exchanger 103 functioning as the evaporator. The first heat exchanger 103 exchanges heat between the refrigerant in the two-phase state flowing thereto and the air supplied by the air-sending device 107 to evaporate the liquid refrigerant contained in the refrigerant in the two-phase state into low-pressure gas refrigerant (single phase). The low-pressure gas refrigerant fed from the first heat exchanger 103 flows into the compressor 101 through the flow switching device 102 to be compressed into high-temperature and high-pressure gas refrigerant, which is then discharged from the compressor 101 again. Thereafter, the above-mentioned cycle is repeated.
Next, the heating operation performed by the air-conditioning apparatus 100 is described. The flow of the refrigerant during the heating operation is indicated by the solid arrows of
As illustrated in
The high-pressure liquid refrigerant fed from the first heat exchanger 103 turns into refrigerant in a two-phase state, that is, gas refrigerant and liquid refrigerant at a low pressure, through the expansion device 104. The refrigerant in the two-phase state flows into the second heat exchanger 105 functioning as the evaporator. The second heat exchanger 105 exchanges heat between the refrigerant in the two-phase state flowing thereto and the air supplied by the air-sending device 107 to evaporate the liquid refrigerant contained in the refrigerant in the two-phase state into low-pressure gas refrigerant (single phase). The low-pressure gas refrigerant fed from the second heat exchanger 105 flows into the compressor 101 through the flow switching device 102 to be compressed into high-temperature and high-pressure gas refrigerant, which is then discharged from the compressor 101 again. Thereafter, the above-mentioned cycle is repeated.
The refrigerant used in the air-conditioning apparatus 100 is not particularly limited. The effects can be exerted even when refrigerants such as 8410, R32, and HFO1234yf are used.
Although the air and the refrigerant are described as examples of a working fluid, the working fluid is not limited thereto. The same effects are exhibited even when other gases, other liquids, or gas-liquid mixture fluids are used. That is, although the working fluid varies, the effects are obtained.
For the air-conditioning apparatus 100, any refrigeration machine oil such as mineral oils, alkyl benzene oils, ester oils, ether oils, and fluorine oils can be used regardless of whether the oil is dissolvable or not in the refrigerant.
Other examples of the air-conditioning apparatus 100 include a water heater, a refrigerating machine, an air-conditioner water-heater combined system, and other apparatus. In any case, manufacture is easy, and heat exchange performance can be improved to improve energy efficiency.
As described above, the air-conditioning apparatus 100 includes the heat source unit according to any one of Embodiment 1 to Embodiment 5. Therefore, the air flowing into the heat source unit can be made to flow along the air inlet portion 6 of the bellmouth 30. Thus, the release of the air can be suppressed, and hence the noise is reduced. Further, according to the air-conditioning apparatus 100, the air inlet portion 6 has a simple shape and therefore can be formed integrally with the air outlet portion 7.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/071189 | 7/19/2016 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2018/016012 | 1/25/2018 | WO | A |
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| 20060177304 | Omori | Aug 2006 | A1 |
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| Number | Date | Country |
|---|---|---|
| H08-210665 | Aug 1996 | JP |
| H11-005252 | Jan 1999 | JP |
| 2004-150654 | May 2004 | JP |
| 2011-111998 | Jun 2011 | JP |
| 2011-179778 | Sep 2011 | JP |
| 2016-011612 | Jan 2016 | JP |
| 2012035577 | Mar 2012 | WO |
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| Number | Date | Country | |
|---|---|---|---|
| 20190137120 A1 | May 2019 | US |
