Fan device, air-conditioning outdoor equipment, and outdoor equipment for hot-water supply heat pump

Abstract

To suppress an increase in airflow resistance and enable achievement of high efficiency, when a member for providing the airflow resistance is arranged on the downstream side of an axial fan.SOLUTION: A fan device 5 comprises an axial fan 11, and a diffuser 12 that is positioned on the downstream side of the axial fan 11. The diffuser 12 has a plurality of annular plates 12a that are concentrically arranged with a gap between them. Each of the annular plates 12a is formed in a truncated cone shape extending radially outward toward the downstream side from the upstream side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fan device, an outdoor unit for an air conditioner, and an outdoor unit for a hot water heat pump. [Background technology]

[0002] For example, Patent Document 1 discloses an outdoor unit for an air conditioner. The outdoor unit disclosed in Patent Document 1 has a heat exchange chamber and a machine chamber inside the main body. The heat exchange chamber is provided with a heat exchanger, an axial fan, a fan motor, and a bell mouth. The outdoor unit disclosed in Patent Document 1 also has a ventilation grill located on the air outlet side of the bell mouth. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-91687 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in Patent Document 1, outdoor units use a large axial fan in the axial direction of the motor (the front-to-rear direction of the outdoor unit). This is because the number of blades is reduced to increase the physical distance between the blades in order to prevent separation vortices from the leading blades from interfering with the trailing blades, resulting in a longer blade chord. However, axial fans with such long blade chords have longer streamlines along the blade tips, resulting in increased leakage flow from the blade tips (i.e., velocity loss at the outer periphery), resulting in poor efficiency. Furthermore, fan guards located downstream of the axial fan typically have an opening ratio of approximately 80%, accounting for 20 to 30% of the overall ventilation resistance of the outdoor unit. Such fan guards hinder efforts to increase the airflow capacity of outdoor units.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to suppress the increase in ventilation resistance when a component that causes ventilation resistance is placed downstream of the axial fan, while also making it possible to achieve high efficiency. [Means for solving the problem]

[0006] The present invention employs the following configuration as a means for solving the above problems.

[0007] A first aspect of the present invention is a fan device comprising an axial fan and a diffuser located downstream of the axial fan, the diffuser having a plurality of annular plates arranged concentrically with gaps between them, each annular plate formed in a truncated cone shape that widens radially outward as it moves from upstream to downstream.

[0008] A second aspect of the present invention is the first aspect, and adopts a configuration in which the thickness dimension of the diffuser in the axial direction, which is the direction along the rotation axis of the axial fan, is larger than the thickness dimension of the axial fan.

[0009] A third aspect of the present invention is the first or second aspect, wherein the axial fan has a plurality of blades and a fan ring connecting blade tips of the plurality of blades.

[0010] A fourth aspect of the present invention is a configuration in which, in the third aspect, a mouth ring is provided that surrounds the axial fan from the radial outside, and at least a portion of the fan ring and the mouth ring are arranged overlapping in the axial direction, which is the direction along the rotational axis of the axial fan.

[0011] A fifth aspect of the present invention is the third or fourth aspect, wherein the axial fan has outer blades, which are blades whose blade tips are fixed to the fan ring, and inner blades, which are blades arranged radially inward of the outer blades, and the number of inner blades is smaller than the number of outer blades.

[0012] A sixth aspect of the present invention is a configuration in which, in any one of the third to fifth aspects, a motor is provided to rotate the axial fan, the axial fan has a hollow boss that protrudes downstream beyond the blades, and the motor is housed in the boss.

[0013] A seventh aspect of the present invention is characterized in that, in any one of the first to sixth aspects, the downstream end of the annular plate has a circular or rectangular shape.

[0014] An eighth aspect of the present invention is a configuration in which, in any one of the first to seventh aspects, a connecting structure member is provided that connects a plurality of the annular plates together, and the connecting structure member is formed in a blade shape that can recover static pressure.

[0015] A ninth aspect of the present invention employs a configuration in which, in any one of the first to eighth aspects, the diffuser is used as a fan guard.

[0016] A tenth aspect of the present invention is an outdoor unit for air conditioning, which employs a configuration including a fan device according to any one of the first to ninth aspects.

[0017] An eleventh aspect of the present invention is an outdoor unit for a hot water supply heat pump, which employs a configuration including the fan device according to any one of the first to ninth aspects. [Effects of the Invention]

[0018] According to the present invention, a diffuser located downstream of an axial fan includes a plurality of concentrically arranged annular plates each having a truncated cone shape that expands radially outward from the upstream side to the downstream side. This diffuser converts the kinetic energy of air discharged from the axial fan into pressure, thereby reducing the air flow velocity. Therefore, even if a component that creates ventilation resistance is located downstream of the diffuser (i.e., downstream of the axial fan), the present invention reduces the air flow velocity passing through the component that creates ventilation resistance, thereby suppressing an increase in ventilation resistance. Therefore, the present invention can suppress an increase in ventilation resistance and achieve high efficiency. Furthermore, the present invention does not require the use of an axial fan with large blades in the axial direction, and a thin, highly efficient axial fan can be used. This also enables high efficiency to be achieved. Therefore, the present invention can suppress an increase in ventilation resistance when a component that creates ventilation resistance is located downstream of the axial fan, thereby achieving high efficiency. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a horizontal cross-sectional view showing a schematic configuration of an outdoor unit equipped with a fan device in a first embodiment of the present invention. [Figure 2] 1 is a schematic enlarged cross-sectional view of a fan device according to a first embodiment of the present invention. [Figure 3] 1 is a front view of an axial flow fan included in a fan device according to a first embodiment of the present invention. [Figure 4] 1 is a schematic partial cross-sectional perspective view including an axial fan, a diffuser, and a mouth ring provided in a fan device according to a first embodiment of the present invention. [Figure 5] 1 is a front view of a diffuser included in a fan device according to a first embodiment of the present invention, viewed from the exhaust opening side. [Figure 6] 3 shows a cross-sectional shape of a strut included in the fan device according to the first embodiment of the present invention. [Figure 7] FIG. 2 is a schematic diagram showing a model used in the simulation of Example 1. [Figure 8]1 is a graph showing the results of a simulation in Example 1. [Figure 9] FIG. 6 is a schematic enlarged cross-sectional view of a fan device according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a horizontal cross-sectional view showing a schematic configuration of an outdoor unit equipped with a fan device according to a third embodiment of the present invention. [Figure 11] FIG. 10 is a schematic diagram showing the general configuration of an air conditioning system according to a fourth embodiment of the present invention. [Figure 12] FIG. 10 is a schematic diagram showing a schematic configuration of a hot water supply heat pump system according to a fifth embodiment of the present invention. [Figure 13] FIG. 10 is a front view of a modified example of the axial flow fan. [Figure 14] 10 is a graph showing the results of a simulation in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a fan device, an outdoor unit for an air conditioner, and an outdoor unit for a hot water supply heat pump according to the present invention will be described with reference to the drawings.

[0021] (First embodiment) Fig. 1 is a horizontal cross-sectional view showing the schematic configuration of an outdoor unit 1 equipped with a fan device of this embodiment. The outdoor unit 1 is used, for example, as an outdoor unit for an air conditioner or an outdoor unit for a hot water heat pump. As shown in Fig. 1, this outdoor unit 1 includes a housing 2, a refrigerant mechanism 3, a heat exchanger 4, a fan device 5, and a fan guard 6.

[0022] The housing 2 houses the refrigerant mechanism 3, the heat exchanger 4, and the fan unit 5. As shown in Fig. 1, the housing 2 has an exhaust opening 2a provided opposite the fan unit 5 and an intake opening 2b provided opposite the heat exchanger 4.

[0023] The housing 2 is formed in a rectangular shape in a plan view, and the exhaust opening 2a and the intake opening 2b are provided on different surfaces. The positions where the exhaust opening 2a and the intake opening 2b are formed are not limited, but in this embodiment, the exhaust opening 2a is formed on the front surface of the housing 2, and the intake opening 2b is formed from the back surface to the side surface of the housing 2.

[0024] Inside the housing 2, a heat exchanger 4 and a fan unit 5 are arranged in this order from the rear surface toward the exhaust opening 2a. Outside air is taken into the housing 2 through the intake opening 2b, passes through the heat exchanger 4 and the fan unit 5, and is exhausted to the outside of the housing 2 through the exhaust opening 2a. In addition, the side of the space inside the housing 2 that houses the heat exchanger 4 and the fan unit 5 is partitioned by a partition wall 2c, and houses a refrigerant mechanism 3 and a control device (not shown).

[0025] The refrigerant mechanism 3 has multiple components that constitute part of the refrigerant circulation system. For example, the refrigerant mechanism 3 has a compressor that compresses the refrigerant, an expansion valve that expands the refrigerant, etc. The refrigerant mechanism 3 is housed in a space partitioned by a partition wall 2c of the housing 2.

[0026] The heat exchanger 4 constitutes part of the refrigerant circulation system and exchanges heat between the refrigerant and outside air. As shown in Fig. 1, the heat exchanger 4 is disposed inside the housing 2 closer to the intake opening 2b than the fan unit 5. The heat exchanger 4 exchanges heat between the outside air taken into the housing 2 through the intake opening 2b and the refrigerant supplied from the refrigerant mechanism 3.

[0027] The fan unit 5 is disposed inside the housing 2 and forms an airflow that passes from the intake opening 2b to the exhaust opening 2a. The fan unit 5 is disposed inside the housing 2 closer to the exhaust opening 2a than the heat exchanger 4. The fan unit 5 is electrically connected to a control device (not shown) and is driven under the control of the control device.

[0028] Fig. 2 is a schematic enlarged cross-sectional view of the fan device 5. As shown in Fig. 2, the fan device 5 includes a fan motor 10, an axial flow fan 11, a diffuser 12, struts 13 (connecting structural members), and a mouth ring 14.

[0029] The fan motor 10 is connected to a power supply (not shown) and converts the power supplied from the power supply into rotational power to rotate the axial flow fan 11. The fan motor 10 is connected to a control device (not shown) and its rotation speed is controlled under the control of the control device.

[0030] 1, the fan motor 10 is disposed closer to the intake opening 2b than the axial fan 11, and is located between the heat exchanger 4 and the axial fan 11. However, as will be described later, it is also possible to provide a housing for the fan motor 10 in the axial fan 11 and to dispose the fan motor 10 closer to the exhaust opening 2a than in this embodiment.

[0031] The axial fan 11 is connected to the output shaft of the fan motor 10 and is driven to rotate about a rotation axis L shown in Fig. 2. In this embodiment, the axial fan 11 is arranged so that the rotation axis L is parallel to the short sides of the rectangular housing 2, as shown in Fig. 1. However, as will be described later, the axial fan 11 can also be arranged so that the rotation axis L is inclined with respect to the short sides of the housing 2.

[0032] 3 is a front view of the axial fan 11. As shown in this figure, the axial fan 11 has a shaft portion 11a, inner blades 11b (blade), an inner ring 11c (fan ring), outer blades 11d (blade), and an outer ring 11e (fan ring).

[0033] In this embodiment, the shaft portion 11a is formed in a disk shape and is disposed at the radial center of the axial flow fan 11. The shaft portion 11a is fixed to the output shaft of the fan motor 10, and directly or indirectly supports the inner blades 11b, the inner ring 11c, the outer blades 11d, and the outer ring 11e.

[0034] The inner blades 11b are blades connected to the outer edge of the shaft portion 11a, and a plurality of inner blades 11b are provided so as to be arranged at equal intervals in the rotation direction of the axial flow fan 11. In this embodiment, as shown in Fig. 3, eight inner blades 11b are provided. However, the number of inner blades 11b is not limited to this. Furthermore, the inner blades 11b may be arranged at unequal intervals in the rotation direction of the axial flow fan 11.

[0035] The inner blades 11b are formed in a shape such that the chord length at the blade root is longer than the chord length at the blade tip, as the chord length increases from the radially inner side toward the radially outer side of the axial fan 11. As shown in Fig. 3, in this embodiment, the leading and trailing edges of the inner blades 11b are parallel or approximately parallel to the radial direction of the axial fan 11 when viewed from the direction along the rotation axis L (hereinafter referred to as the axial direction).

[0036] The number of inner blades 11b is smaller than that of outer blades 11d, and the blade chord length is longer than that of outer blades 11d. By reducing the number of inner blades 11b compared to outer blades 11d, the blade chord length of the inner blades 11b can be increased while preventing the inner blades 11b from becoming larger in the axial direction. By increasing the blade chord length of the inner blades 11b, the contact area between the shaft portion 11a and the inner blades 11b increases, and the strength of the axial flow fan 11 can be improved.

[0037] The phrase "the chord length of the inner blade 11b is longer than that of the outer blade 11d" means that the chord length at the tip of the inner blade 11b is longer than the chord length at the root of the outer blade 11d. Therefore, for example, the chord length at the root of the inner blade 11b may be shorter than the chord length at the root of the outer blade 11d. However, in this embodiment, in order to increase the contact area between the shaft portion 11a and the inner blade 11b, the chord length at the root of the inner blade 11b is longer than the chord length at the root of the outer blade 11d.

[0038] 3, in this embodiment, the height of the inner blade 11b (the radial size of the axial fan 11) is smaller than that of the outer blade 11d. In this embodiment, the height of the inner blade 11b is half or less of that of the outer blade 11d. However, the ratio between the height of the inner blade 11b and the height of the outer blade 11d can be changed.

[0039] The inner ring 11c is an annular ring member whose inner peripheral surface is connected to the blade tips of the inner blades 11b. In this embodiment, all of the inner blades 11b are formed to the same height, and the blade tips of all of the inner blades 11b are connected to the inner ring 11c. This inner ring 11c prevents the airflow flowing along the surface of the inner blades 11b from leaking radially outward from the blade tips of the inner blades 11b.

[0040] The inner ring 11c is connected to the blade root of the outer blade 11d and supports the outer blade 11d. The outer blade 11d is connected to the outer peripheral surface of the inner ring 11c. That is, as shown in FIG. 1, the inner ring 11c is disposed between the inner blade 11b and the outer blade 11d in the radial direction of the axial flow fan 11.

[0041] The outer blades 11d are blades connected to the outer peripheral surface of the inner ring 11c, and a plurality of them are provided so as to be arranged at equal intervals in the rotation direction of the axial flow fan 11. In this embodiment, as shown in Fig. 3, 16 outer blades 11d are provided. However, the number of outer blades 11d is not limited to this. Furthermore, the outer blades 11d may be arranged at unequal intervals in the rotation direction of the axial flow fan 11.

[0042] The outer blade 11d is formed in a shape in which the blade chord length increases from the radially inner side toward the radially outer side of the axial fan 11, such that the blade chord length at the blade root is longer than the blade tip. As shown in Fig. 3, in this embodiment, the leading edge and trailing edge of the outer blade 11d are parallel or approximately parallel to the radial direction of the axial fan 11 when viewed from the axial direction. Also, in this embodiment, the leading edge of the blade tip of the outer blade 11d is not advanced in the circumferential direction of the axial fan 11 relative to the leading edge position of the blade root, but is aligned with the leading edge position of the blade root in the circumferential direction of the axial fan 11.

[0043] The outer blades 11d are more numerous than the inner blades 11b and have a shorter chord length than the inner blades 11b. By increasing the number of outer blades 11d compared to the inner blades 11b, the chord length of each outer blade 11d can be shortened, preventing the outer blades 11d from becoming larger in the axial direction. By shortening the chord length of the outer blades 11d, the streamlines flowing along the blade tips of the outer blades 11d are shortened, reducing leakage flow from the blade tips (i.e., velocity loss at the outer periphery), and improving efficiency.

[0044] As described above, the chord length of the outer blade 11d being shorter than the chord length of the inner blade 11b means that the chord length at the root of the outer blade 11d is shorter than the chord length at the tip of the inner blade 11b. Therefore, for example, the chord length at the tip of the outer blade 11d may be longer than the chord length at the tip of the inner blade 11b.

[0045] The outer ring 11e is an annular ring member in which the blade tips of the outer blades 11d are connected to the inner circumferential surface. In this embodiment, all of the outer blades 11d are formed to the same height, and the blade tips of all of the outer blades 11d are connected to the outer ring 11e. This outer ring 11e prevents the airflow flowing along the surface of the outer blades 11d from leaking radially outward from the blade tips of the outer blades 11d.

[0046] Such an axial flow fan 11 generates an airflow from the intake opening 2b to the exhaust opening 2a when rotated by the fan motor 10. Therefore, in the following description, based on the direction of the airflow generated by the axial flow fan 11, the intake opening 2b side will be referred to as the upstream side, and the exhaust opening 2a side will be referred to as the downstream side.

[0047] 4 is a schematic partial cross-sectional perspective view including the axial fan 11, the diffuser 12, and the mouth ring 14. As shown in FIGS. 1 and 4, the diffuser 12 is disposed opposite the axial fan 11. As shown in FIG. 1, the diffuser 12 is disposed opposite the fan guard 6, and is located between the axial fan 11 and the fan guard 6. In other words, the diffuser 12 is located downstream of the axial fan 11.

[0048] The diffuser 12 increases the pressure of the airflow created by the axial fan 11 by converting the kinetic energy of the airflow into pressure. In other words, the axial fan 11 increases the pressure of the air, thereby reducing the flow velocity of the air.

[0049] 4, the diffuser 12 has a plurality of annular plates 12a. Each of these annular plates 12a is formed in a truncated shape that widens radially outward from the upstream side to the downstream side. In other words, each annular plate 12a is formed in a shape that is obtained by cutting a hollow cone along two planes perpendicular to the axis and consisting of a portion of the cone located between these planes.

[0050] In this embodiment, each annular plate 12a is formed in a shape consisting of a portion of a cone. However, the shape of the annular plate 12a is not limited to this. For example, the annular plate may be formed in a shape consisting of a portion of a regular polygonal pyramid. It is also possible to form the annular plate so that its shape changes from a cone to a regular polygonal pyramid as it moves from the upstream side to the downstream side. It is also possible to form the annular plate in a shape consisting of a portion of an oblique pyramid.

[0051] These multiple annular plates 12a are arranged concentrically with gaps between them in the radial direction. Each annular plate 12a is formed so that the annular plates 12a located radially outward have a larger diameter. In the diffuser 12 formed by such multiple annular plates 12a, the flow path cross-sectional area increases from the upstream side to the downstream side. As air flows from the upstream side to the downstream side through the flow path formed by such a diffuser 12, the kinetic energy (dynamic pressure) of the air is converted into pressure (static pressure) (i.e., static pressure is recovered), and the air flow velocity is reduced.

[0052] 1, 2, and 4, in this embodiment, the thickness dimension of the diffuser 12 in the axial direction is larger than the thickness dimension of the axial fan 11. In other words, as shown in Fig. 2, the thickness dimension Da of the diffuser 12 is larger than the thickness dimension Db of the axial fan 11. In this embodiment, the thickness dimension Da of the diffuser 12 is at least twice the thickness dimension Db of the axial fan 11.

[0053] For example, it is preferable that the sum of the thickness dimension Da of the diffuser 12 and the thickness dimension Db of the axial fan 11 is equal to or less than the axial thickness dimension of the axial fan disclosed in the above-mentioned Patent Document 1. This allows the axial size of the outdoor unit 1 of this embodiment to be equal to or less than that of the outdoor unit disclosed in Patent Document 1.

[0054] 5 is a front view of the diffuser 12 as viewed from the exhaust opening 2a side. As shown in this figure, struts 13 connect each of the annular plates 12a. In this embodiment, the struts 13 are formed in a cross shape, with two rod-shaped members extending linearly in the radial direction and connected at their radial center to form an integrated unit. Such struts 13 are connected to the downstream ends of each of the annular plates 12a. Note that the struts 13 may be formed in the shape of a single rod-shaped member or in the shape of three or more rod-shaped members integrated together.

[0055] FIG. 6 shows the cross-sectional shape of a strut 13. For example, as shown in FIG. 6(a), the strut 13 is formed so that it has a rounded front end, becomes thinner toward the rear end, and has a curved airfoil shape. Alternatively, as shown in FIG. 6(b), the strut 13 may be formed so that it has a substantially uniform thickness from the front end to the rear end and has a curved airfoil shape. Such struts 13 are preferably oriented so as to convert the dynamic pressure of the air flowing from the upstream side to the downstream side into static pressure. Use of such struts 13 can further reduce the air flow velocity. Furthermore, as shown in FIG. 6, curving the struts 13 can weaken the swirling component of the swirling flow and reduce the absolute velocity.

[0056] The diffuser 12, in which each annular plate 12a is integrated by such struts 13, is supported on the housing 2 via, for example, a mouth ring 14. For example, as shown in FIG. 2, the annular plate 12a located on the outermost side in the radial direction is connected to the mouth ring 14, and the mouth ring 14 is connected to the housing 2 by a fixing portion (not shown).

[0057] 1, 2, and 4, the mouth ring 14 is provided so as to surround the axial fan 11 from the radially outer side. Such a mouth ring 14 reduces the gap between itself and the axial fan 11, thereby preventing air from flowing back radially outward from the axial fan 11.

[0058] In this embodiment, as shown in Fig. 2, the outer ring 11e and the mouth ring 14 are arranged so that they partially overlap in the axial direction. In this embodiment, the downstream portion of the outer ring 11e and the upstream portion of the mouth ring 14 are arranged so that they overlap in the axial direction. A minute gap S is formed between the outer ring 11e and the mouth ring 14.

[0059] When the axial fan 11 is rotationally driven with such a gap S formed, it is expected that the air in the gap S will be sucked downstream (towards the diffuser 12) from the gap S due to the shear force acting on the air in the gap S. Therefore, even if the pressure on the downstream side of the axial fan 11 is higher than on the upstream side due to the diffuser 12, it is possible to prevent the air from flowing backward through the gap S (from the downstream side to the upstream side).

[0060] Returning to Fig. 1, the fan guard 6 is disposed downstream of the diffuser 12. The fan guard 6 is a member for preventing foreign objects such as human fingers from coming into contact with the fan device 5 from outside the outdoor unit 1. The fan guard 6 is a mesh-like member with many gaps formed therein that are large enough that, for example, a human finger cannot be inserted.

[0061] Such a fan guard 6 is attached to the housing 2 so as to block the exhaust opening 2a of the housing 2, and is disposed midway along the flow path of the airflow generated by the fan unit 5. For this reason, the fan guard 6 acts as a resistance to the airflow. In other words, although the fan guard 6 can prevent the intrusion of foreign matter, it is a component that acts as a resistance to ventilation.

[0062] In the outdoor unit 1 of this embodiment configured as described above, when the fan device 5 is driven, an airflow is formed that flows from the intake opening 2b to the exhaust opening 2a. Specifically, when power is supplied to the fan motor 10 of the fan device 5, rotational power is generated by the fan motor 10. The rotational power generated by the fan motor 10 is transmitted to the axial fan 11. The axial fan 11, to which the rotational power is transmitted from the fan motor 10, rotates in the circumferential direction about the rotation axis L. When the axial fan 11 rotates, the inner blades 11b and outer blades 11d of the axial fan 11 cause air to flow from the upstream side to the downstream side, thereby forming an airflow that flows from the upstream side to the downstream side.

[0063] The airflow thus formed flows into the housing 2 through the intake opening 2b and passes through the heat exchanger 4. As the airflow passes through the heat exchanger 4, heat is exchanged between the air and the refrigerant. After passing through the heat exchanger 4, kinetic energy is imparted to the airflow by the axial flow fan 11, and the airflow flows into the diffuser 12. The airflow that flows into the diffuser 12 is slowed down by converting the kinetic energy into pressure. The airflow slowed down by the diffuser 12 passes through the fan guard 6 and is discharged to the outside of the housing 2.

[0064] The fan device 5 of this embodiment as described above includes an axial fan 11 and a diffuser 12. The diffuser 12 is located downstream of the axial fan 11. The diffuser 12 also has annular plates 12a. A plurality of the annular plates 12a are concentrically arranged with gaps between them. Each annular plate 12a is formed in a truncated cone shape that widens radially outward from the upstream side to the downstream side.

[0065] In the fan device 5 of this embodiment, the diffuser 12 located downstream of the axial fan 11 includes a plurality of concentrically arranged annular plates 12a each having a truncated cone shape that widens radially outward from the upstream side to the downstream side. The diffuser 12 converts the kinetic energy of the air discharged from the axial fan 11 into pressure, thereby reducing the air flow velocity. Therefore, even if a component that creates ventilation resistance is located downstream of the diffuser 12 (i.e., downstream of the axial fan 11), the fan device 5 of this embodiment reduces the air flow velocity passing through the component that creates ventilation resistance, thereby suppressing an increase in ventilation resistance. Therefore, the fan device 5 of this embodiment can achieve high efficiency by suppressing an increase in ventilation resistance.

[0066] Furthermore, according to the fan device 5 of this embodiment, the speed of the air passing through the fan guard 6 is reduced by the diffuser 12, so that the noise generated by the air passing through the fan guard 6 can be reduced.

[0067] Furthermore, with the fan device 5 of this embodiment, it is not necessary to use an axial fan 11 with large blades in the axial direction, and a thin, highly efficient axial fan 11 can be used. This also enables the fan device 5 of this embodiment to achieve high efficiency. Therefore, the fan device 5 of this embodiment can suppress an increase in ventilation resistance when a member that causes ventilation resistance is placed downstream of the axial fan 11, making it possible to achieve high efficiency.

[0068] Furthermore, in the fan device 5 of this embodiment, the thickness dimension Da of the diffuser 12 in the axial direction is larger than the thickness dimension Db of the axial flow fan 11. With the fan device 5 of this embodiment, the air flow velocity can be sufficiently reduced, the increase in ventilation resistance can be further suppressed, and efficiency can be further improved.

[0069] Furthermore, the fan device 5 of this embodiment can use a thin axial flow fan 11 with a small thickness Db. The thin axial flow fan 11 has a short chord length of the blades (inner blade 11b and outer blade 11d). As a result, the streamlines flowing along the blade tips are shorter, which reduces leakage flow from the blade tips (i.e., velocity loss at the outer periphery) and improves efficiency.

[0070] In the fan device 5 of this embodiment, the axial fan 11 has a plurality of blades (inner blade 11b and outer blade 11d). The axial fan 11 also has fan rings (inner ring 11c and outer ring 11e) that connect the blade tips of the plurality of blades. With the fan device 5 of this embodiment, leakage flow from the blade tips can be reduced, improving efficiency.

[0071] The fan device 5 of this embodiment also includes a mouth ring 14. The mouth ring 14 is provided so as to surround the axial fan 11 from the radial outside. The outer ring 11e and the mouth ring 14 are arranged so as to at least partially overlap in the axial direction.

[0072] According to the fan device 5 of this embodiment, the outer ring 11e and the mouth ring 14 form a minute gap S between the outer ring 11e and the mouth ring 14. According to the fan device 5 of this embodiment, the shear force acting on the air in the gap S can prevent the air from flowing back through the gap S, thereby further improving efficiency.

[0073] In the fan unit 5 of this embodiment, the axial fan 11 has outer blades 11d and inner blades 11b. The outer blades 11d have blade tips fixed to the outer ring 11e. The inner blades 11b are arranged radially inward of the outer blades 11d. The number of inner blades 11b is also smaller than the number of outer blades 11d.

[0074] In the fan device 5 of this embodiment, the number of inner blades 11b is smaller than the number of outer blades 11d, so the chord length of the inner blades 11b can be made longer than that of the outer blades 11d. This increases the contact area between the shaft portion 11a and the inner blades 11b, thereby improving the strength of the axial flow fan 11.

[0075] Furthermore, in the fan device 5 of this embodiment, the downstream end shape of the annular plate 12a is circular. The upstream end shape of the annular plate 12a is also circular to match the axial fan 11. Therefore, when the downstream end shape of the annular plate 12a is circular, both the upstream and downstream end shapes of the annular plate 12a can be circular. Therefore, for each annular plate 12a, whose diameter increases toward the downstream side, all cross-sectional shapes perpendicular to the axial direction are similar across the entire axial region. This makes it easy to form the annular plate 12a. Furthermore, the rate of change in the cross-sectional area of ​​the flow path formed by the diffuser 12 is constant in the axial direction. This prevents turbulence from occurring inside the diffuser 12.

[0076] The downstream end of the annular plate 12a may have a rectangular shape. By making the downstream end of the annular plate 12a rectangular, the flow path area at the downstream end of the diffuser 12 can be increased compared to when the annular plate 12a is circular. This allows the static pressure recovery area to be expanded, further improving efficiency.

[0077] The fan device 5 of this embodiment also has struts 13. The struts 13 connect the multiple annular plates 12a together. The struts 13 are formed in a blade shape that can recover static pressure. According to the fan device 5 of this embodiment, static pressure can also be recovered by the struts 13, further improving efficiency.

[0078] Example 1 A simulation was performed to confirm the performance of the axial fan 11 of the first embodiment. FIG. 7 is a schematic diagram showing the model used in this simulation. As shown in this figure, a cylindrical flow field was set up in this simulation. One end face of the cylindrical flow field was set as an air inlet surface 100, the other end face of the cylindrical flow field was set as an air outlet surface 101, and the inner peripheral surface of the flow field was set as a free-slip surface. A rotation region 103 in which the axial fan 11 rotates was set up midway through the flow field, and the diameter of the flow field was set to be slightly larger than the diameter D of the axial fan 11. The flow path length on the upstream side of the axial fan 11 was set to twice the diameter D of the axial fan 11, and the flow path length on the downstream side of the axial fan 11 was set to four times the diameter D of the axial fan 11. Furthermore, the peripheral surface of the rotation region 103 was set as a no-slip bell-mouth surface 104.

[0079] The flow velocity on the inlet surface 101 was set to a specified value, and the static pressure on the outlet surface 101 was set to 0 Pa (gauge pressure). The diameter D of the axial flow fan 11 was set to 440 mm, and the rotation speed of the axial flow fan 11 was set to 700 rpm. In this simulation, a steady-state analysis was performed using the ALE method (Arbitrary Lagrangian and Eularian Method), and Realizable k-ε was used as the turbulence model.

[0080] Furthermore, for comparison with the axial fan 11 of the first embodiment, a simulation was performed under the same conditions using a propeller fan (hereinafter referred to as a comparative axial fan) used in a commercially available energy-saving outdoor unit (such as the outdoor unit disclosed in Patent Document 1) as an axial fan with a large axial direction.

[0081] Figure 8 is a graph showing the results of this simulation. In Figure 8, the horizontal axis represents the flow coefficient, and the vertical axis represents the static pressure coefficient. Note that the vertical axis is standardized by the static pressure coefficient value of the comparative axial fan with a flow coefficient of 0.25. In other words, the vertical axis in Figure 8 can also be interpreted as the static pressure increase rate.

[0082] 8, it was confirmed that the performance of the axial flow fan 11 of the first embodiment significantly exceeds that of the comparative axial flow fan in almost all flow rate ranges. Furthermore, it is believed that the performance of the axial flow fan 11 of the first embodiment exceeds that of the comparative axial flow fan at an open flow rate (static pressure coefficient 0), and it is clear that the performance of the axial flow fan 11 of the first embodiment is high.

[0083] As mentioned above, the comparative axial fan used in this simulation is a high-performance product commercially available in Japan in recent years. The axial fan 11 of this embodiment has the same impeller diameter and rotation speed as the comparative axial fan. Specifically, the impeller diameter is 440 mm and the rotation speed is 700 rpm. When comparing the thickness dimension (axial length of the impeller) of the comparative axial fan, the comparative axial fan is 0.38 times the impeller diameter, while the axial fan 11 of this embodiment is 0.11 times. Furthermore, the thickness dimension including the axial fan 11 and the diffuser 12 of this embodiment is 0.34 times. Therefore, in this simulation, the numerical analysis was performed on the axial fan 11 of this embodiment, which is thinner in shape and dimensions than the comparative axial fan. The analytical method used was the same: steady-state RANS analysis (turbulence analysis).

[0084] Because the axial fan 11 of this embodiment has a higher static pressure rise than the comparative axial fan, the axial fan 11 of this embodiment can reduce its rotation speed when obtaining the same static pressure rise as the comparative axial fan. Therefore, the axial fan 11 of this embodiment can reduce axial power and power consumption. Furthermore, when the axial fan 11 is installed in a housing, the reduction in main flow velocity by the diffuser 12 can be expected to have the effect of reducing losses in the fan guard 6. Furthermore, by using the diffuser 12 as a fan guard, the effect of reducing losses can be further enhanced without installing a fan guard on the housing.

[0085] Regarding noise reduction, the impeller peripheral speed is estimated so as to reduce the static pressure increase due to the increased static pressure caused by the diffuser 12 under the condition of a flow coefficient of 0.2. For example, the static pressure increase is reduced to approximately 0.75 times the dynamic pressure. Dynamic pressure is proportional to the square of the peripheral speed. Therefore, the peripheral speed can be reduced to 0.867 times. Fan noise has the characteristic of being proportional to the sixth power of the flow velocity. Taking this into consideration, the noise reduction effect of the diffuser 12 is expected to be around 4 dB, which is at a level that can be fully felt.

[0086] Compared to the comparative axial fan, the axial fan 11 of this embodiment tends to have a steeper gradient of the static pressure curve in the region where the flow coefficient is large, as shown in Figure 8. Therefore, even if frost or the like adheres to the heat exchanger 4 and the ventilation resistance curve of the housing increases, the drop in the matching flow coefficient is small. In other words, compared to the comparative axial fan, the axial fan 11 of this embodiment is less sensitive to changes in the housing ventilation resistance, and is able to maintain high heat exchange performance.

[0087] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to Fig. 9. In the description of this embodiment, the description of the same parts as those in the first embodiment will be omitted or simplified.

[0088] 9 is a schematic enlarged cross-sectional view of a fan device 5A of this embodiment. As shown in this figure, in this embodiment, an axial flow fan 11 has a boss 11f instead of the shaft portion 11a of the first embodiment.

[0089] The boss 11f is formed in the shape of a hollow container with an open end on the upstream side and a closed end on the downstream side. As shown in Fig. 9, the boss 11f is provided so as to protrude downstream beyond the inner blade 11b and the outer blade 11d. The boss 11f is a housing portion for housing the fan motor 10.

[0090] Furthermore, a plurality of ventilation holes 11g are provided at the closed end of the boss 11f. Air passes through the boss 11f via the ventilation holes 11g, and the fan motor 10 is cooled by the air passing through the ventilation holes 11g in this manner.

[0091] In this embodiment, the fan motor 10 is housed inside the boss 11f. The output end of the fan motor 10 is connected to the closed end of the boss 11f. In this embodiment, the fan motor 10 is positioned closer to the exhaust opening 2a than in the first embodiment.

[0092] According to the fan device 5A of this embodiment, the axial thickness dimension is smaller than that of the fan device 5 of the first embodiment. Therefore, the fan device 5A of this embodiment makes it possible to reduce the thickness of the outdoor unit 1. Furthermore, according to the fan device 5A of this embodiment, even if the fan motor 10 is large in the axial direction, the fan motor 10 can be accommodated in the boss 11f, thereby preventing the fan device 5A from becoming large in the axial direction.

[0093] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Fig. 10. In the description of this embodiment, the description of the same parts as those in the first embodiment will be omitted or simplified.

[0094] 10 is a horizontal cross-sectional view showing a schematic configuration of the outdoor unit 1A of this embodiment. As shown in this figure, in the outdoor unit 1A of this embodiment, the axial flow fan 11 is arranged so that the rotation axis L is inclined with respect to the short side of the housing 2.

[0095] According to the fan device 5 provided in the outdoor unit 1A of this embodiment, the diameter of the axial fan 11 can be made larger than that of the first embodiment without changing the size of the housing 2. This makes it possible to improve efficiency compared to the first embodiment.

[0096] If the axial flow fan 11 is tilted so that a part of the diffuser 12 protrudes outside the housing 2, the part of the diffuser 12 that protrudes outside the housing 2 may be cut off.

[0097] The axial flow fan 11 of this embodiment can also reduce the rotation speed if the static pressure rise is the same as that of the comparative axial flow fan.

[0098] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described with reference to Fig. 11. In the description of this embodiment, the description of the same parts as those in the first embodiment will be omitted or simplified.

[0099] Fig. 11 is a schematic diagram showing the general configuration of an air conditioning system 200 of this embodiment. As shown in this diagram, the air conditioning system 200 of this embodiment includes the outdoor unit 1 of the first embodiment and an indoor unit 201. The indoor unit 201 is connected to the outdoor unit 1. In addition, in the air conditioning system 200 of this embodiment, a refrigerant is circulated between the indoor unit 201 and the outdoor unit 1. In addition, the indoor unit 201 includes a heat exchanger that exchanges heat between the refrigerant and indoor air.

[0100] The outdoor unit 1 of such an air conditioning system 200 is equipped with a fan device 5 and is highly efficient as described above. Therefore, for example, the power consumption of the air conditioning system 200 can be reduced, resulting in an air conditioning system 200 with low energy consumption.

[0101] The air conditioning system 200 may include the outdoor unit 1A of the third embodiment. It is also possible to provide a fan device 5 in the indoor unit 201. By providing the fan device 5 in the indoor unit 201, the indoor unit 201 can be made highly efficient.

[0102] (Fifth embodiment) Next, a fifth embodiment of the present invention will be described with reference to Fig. 12. In the description of this embodiment, the description of the same parts as those in the first embodiment will be omitted or simplified.

[0103] 12 is a schematic diagram showing the general configuration of a hot water supply heat pump system 300 of this embodiment. As shown in this figure, the hot water supply heat pump system 300 of this embodiment includes the outdoor unit 1 of the first embodiment and a hot water storage unit 301. Note that, for example, in this embodiment, the outdoor unit 1 further includes a heat exchanger that exchanges heat between a refrigerant and water.

[0104] The hot water storage unit 301 is a unit that stores hot water generated by heating water inside the outdoor unit 1, and supplies the stored hot water to the room or the like under the control of a control device (not shown).

[0105] As described above, the outdoor unit 1 of such a hot water supply heat pump system 300 has high efficiency. Therefore, for example, the power consumption of the hot water supply heat pump system 300 can be reduced, resulting in a hot water supply heat pump system 300 with low energy consumption.

[0106] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0107] For example, in the above embodiment, the axial fan 11 includes an inner blade 11b and an outer blade 11d, and the blades are divided in the radial direction. However, the present invention is not limited to this configuration. Fig. 13 is a front view of a modified example of the axial fan 11. As shown in this figure, the axial fan 11 can also be configured such that the blade 11h is not divided in the radial direction.

[0108] In the above embodiment, the outer ring 11e is provided at the radially outermost position of the axial flow fan 11. However, the present invention is not limited to this, and it is also possible to adopt a configuration that does not include the outer ring 11e (fan ring).

[0109] In the above embodiment, the leading edge of the blade tip is not advanced in the circumferential direction of the axial fan relative to the leading edge of the blade root, but is positioned radially. However, the present invention is not limited to this. For example, the leading edge of the blade tip may be advanced or receded compared to the above embodiment.

[0110] In the above embodiment, the fan device of the present invention is described as being applied to an outdoor unit. However, the present invention is not limited to this. For example, the fan device of the present invention can be applied to a ventilation fan, a circulator, or a vehicle fan device. The fan device of the present invention can also be applied to a fan device for cooling semiconductor chips, projectors, electronic devices, etc.

[0111] Example 2 A simulation was performed to confirm the performance of the fan device 5 of the first embodiment. Fig. 14 is a graph showing the results of this simulation. In this simulation, the thickness dimension Da of the diffuser 12, relative to the thickness dimension Db of the axial fan 11, was compared with the rate of static pressure increase. The rate of static pressure increase indicates the rate of static pressure increase when the thickness dimension Da of the diffuser 12 is changed, relative to the static pressure increase when the thickness dimension Db of the axial fan 11 and the thickness dimension Da of the diffuser 12 are the same.

[0112] In this simulation, three axial fans 11 (fan A, fan B, and fan C) with different shapes were used. For fan A, the angle of the diffuser 12 with respect to the rotation axis L was kept constant, the flow coefficient was set to 0.2, and the simulation was performed under conditions where the thickness dimension Da of the diffuser 12 relative to the thickness dimension Db of the axial fan 11 was smaller than 1 and larger than 1. The results obtained from the simulation using fan A are plotted with white triangles.

[0113] For Fans B and C, simulations were performed under the condition that the thickness dimension Da of the diffuser 12 was 1.6 or greater relative to the thickness dimension Db of the axial fan 11. The results obtained in the simulation using Fan B are plotted with black circles. The results obtained in the simulation using Fan C are plotted with white squares. For Fans B and C, simulations were performed under a first flow rate condition and a second flow rate condition different from the first flow rate coefficient. The results obtained under the first flow rate condition are shown connected by a dashed line. The results obtained under the second flow rate condition are shown connected by a dotted line.

[0114] As can be seen from the results of the simulation using fan A, the static pressure increase rate is greater when the thickness Da of diffuser 12 relative to the thickness Db of axial fan 11 is greater than 1, compared to when the thickness Da of diffuser 12 relative to the thickness Db of axial fan 11 is equal to or less than 1 (i.e., when the thickness Da of diffuser 12 is equal to or less than the thickness Db of axial fan 11). Therefore, it is preferable that the thickness Da of diffuser 12 be greater than the thickness Db of axial fan 11.

[0115] Furthermore, the results of the simulation using Fan B and Fan C also showed that the static pressure increase rate tends to increase as the thickness dimension Da of the diffuser 12 becomes larger than the thickness dimension Db of the axial flow fan 11. [Explanation of symbols]

[0116] 1...outdoor unit, 1A...outdoor unit, 2...casing, 2a...exhaust opening, 2b...intake opening, 2c...partition wall, 3...refrigerant mechanism section, 4...heat exchanger, 5...fan device, 5A...fan device, 6...fan guard, 7...filter section, 10...fan motor (motor), 11...axial fan, 11a...shaft section, 11b...inner blade (blade), 11c...inner ring (fan ring), 11d...outer blade (blade), 11e...outer ring (fan ring), 11f...boss, 11g...vent, 12...diffuser, 12a...annular plate, 13...strut (connecting structural member), 14...mouth ring, 200...air conditioning system, 201...indoor unit, 300...hot water supply heat pump system, 301...hot water storage unit, L...rotation axis core, S...gap

Claims

1. An axial fan, a diffuser located downstream of the axial flow fan; Equipped with The diffuser is a plurality of annular plates arranged concentrically with gaps between them; Each annular plate is formed in a truncated cone shape that widens radially outward from the upstream side to the downstream side, In the axial direction that is the direction along the rotation axis of the axial flow fan, The thickness of the diffuser is greater than the thickness of the axial flow fan. A fan device characterized by:

2. The axial flow fan is Multiple wings and a fan ring connecting the tips of the plurality of blades; 2. The fan device according to claim 1, further comprising:

3. a mouth ring surrounding the axial flow fan from the radially outer side, The fan ring and the mouth ring are arranged so as to overlap at least partially in the axial direction, which is the direction along the rotation axis of the axial flow fan.

3. The fan device according to claim 2.

4. The axial flow fan is an outer vane, the vane having a tip fixed to the fan ring; an inner blade, which is the blade arranged radially inward of the outer blade; and The inner vanes are fewer in number than the outer vanes 3. The fan device according to claim 2.

5. a motor that rotates the axial flow fan, the axial flow fan has a hollow boss that protrudes downstream beyond the blades, The motor is housed in the boss.

3. The fan device according to claim 2.

6. 6. The fan device according to claim 1, wherein the downstream end of the annular plate has a circular or rectangular shape.

7. a connecting structure member that connects the plurality of annular plates together; The connecting structure member is formed in a blade shape that allows static pressure recovery.

6. The fan device according to claim 1, wherein the first and second electrodes are electrically connected to the first and second electrodes.

8. The diffuser is used as a fan guard.

6. The fan device according to claim 1, wherein the first and second electrodes are electrically connected to the first and second electrodes.

9. An air conditioning outdoor unit, A fan device according to any one of claims 1 to 5 is provided. An outdoor unit for air conditioning.

10. An outdoor unit for a hot water heat pump, A fan device according to any one of claims 1 to 5 is provided. An outdoor unit for a hot water heat pump.

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