JP5773903B2 - Blower, outdoor unit and refrigeration cycle apparatus - Google Patents

Description

  The present invention relates to an outdoor unit or the like according to a configuration of an air conditioner or the like, for example.

  For example, there is a blower (fan unit) that rotates a propeller fan having blades (propellers) to generate an air flow and blows air (cooling, exhaust heat, etc.). A blower having such a propeller fan is used in a wide range of fields such as an outdoor unit (outdoor unit) of a refrigeration air conditioner, a refrigerator, a ventilation fan, a cooling device such as a computer (see, for example, Patent Document 1). For example, when the propeller fan of such a blower is rotated, sound is generated from the outdoor unit.

Japanese Patent No. 4003541

  Here, for example, an outdoor unit of an air conditioner is often installed outdoors. The sound generated by the outdoor unit due to the rotation of the propeller fan included in the blower may become noise and cause inconvenience to neighboring residents. For this reason, the noise reduction of an air blower is calculated | required. Moreover, in order to prevent global warming, energy saving of the air conditioner (outdoor unit) is required. In this case, increasing the air volume of the outdoor unit is an effective means. However, increasing the air volume increases noise and causes inconvenience to neighboring residents. For this reason, reducing the noise of the blower is an important technology in order to suppress inconvenience to neighboring residents and to save energy.

  Therefore, an object of the present invention is to obtain a blower or the like that can suppress noise, for example.

A blower according to the present invention includes a propeller fan having a plurality of blades that rotate around a rotating shaft to generate a gas flow, and a cylindrical cylinder outside the outer peripheral end of the blades along the rotation direction of the blades of the propeller fan. A bell tube for rectifying the gas, forming a straight wall portion that becomes a wall surface, a wall surface that forms a blow-off side opening portion that is a gas blowing side and a suction side opening portion that is a suction side from the straight pipe portion The fan guard having a grid covering the outlet side opening of the bell mouth, and the cylindrical windward straight portion parallel to the straight tube portion of the bell mouth and the leeward straight portion are connected by a substantially S-shaped curved portion. A sound insulation plate having a wall surface and attached between the fan guard and the propeller fan is provided.

  In the blower according to the present invention, since the sound insulating plate is attached between the fan guard and the propeller fan, noise generated by the rotation of the propeller fan can be suppressed. Further, by suppressing noise, energy loss related to noise can be suppressed and energy saving can be achieved.

It is a figure showing the outline of the air blower concerning Embodiment 1 of this invention. It is a figure showing an example of the outdoor unit 6 which accommodates the air blower concerning Embodiment 1 of this invention. It is a figure showing another example of the outdoor unit 6 which accommodates the air blower concerning Embodiment 1 of this invention. FIG. 2 is a diagram showing a trajectory line coming out from the blade surface of the propeller fan 1. It is a figure which shows distribution of the rms value of the static pressure fluctuation | variation in a bellmouth wall surface. It is a figure which shows the outline of the air blower provided with the sound insulation board 13 which concerns on Embodiment 1. FIG. It is a figure showing the sound insulation board. It is a figure for demonstrating the fixing method etc. of the sound insulation board. It is a figure for demonstrating the measuring method of PWL called a 10-point method. It is a figure for demonstrating the air blower concerning Embodiment 2 of this invention. It is a figure for demonstrating the air blower concerning Embodiment 3 of this invention. It is a figure for demonstrating the air blower concerning Embodiment 4 of this invention. It is a block diagram of the frozen air conditioning apparatus which concerns on Embodiment 5 of this invention.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an outline of a blower according to Embodiment 1 of the present invention. In FIG. 1, the cross section of the propeller fan 1 and the bell mouth 20 is shown. The blower of the present embodiment is mounted on an outdoor unit of a refrigeration cycle apparatus such as an air conditioner.

  The propeller fan 1 is an axial fan that generates a flow of air (fluid) by rotating a plurality of blades (propellers, blades) around a rotation axis by driving a motor or the like (not shown) that receives electric power. . Although not particularly limited, the propeller fan 1 will be described here as a fan having a forward blade shape.

  The bell mouth 20 covers the propeller fan 1 along the circumferential direction (rotation direction) of the propeller fan 1 (surrounds the periphery of the propeller fan 1), and rectifies the air flow generated by the rotation of the propeller fan 1. For this reason, a circular wall surface is formed around the propeller fan 1. The bell mouth 20 has a suction opening 2, a straight pipe portion 3, and a diffuser portion 4.

  In general, the suction opening 2 is a portion (suction opening) that is open to suck air (gas) on the upstream side (suction side) of the bell mouth 20. In the bell mouth 20 of the present embodiment, the distance between the rotating shaft of the propeller fan 1 and the terminal portion of the suction opening 2 (the diameter of the opening portion) is between the rotating shaft and the surface of the straight pipe portion 3. It is longer than the distance (the diameter of the straight pipe portion 3) (the end of the suction opening 2 has an extension). And the inner wall surface (opposite surface with the propeller fan 1) from the suction side termination part of the straight pipe part 3 to the termination | terminus of the suction opening part 2 is made into the curved surface (a cross-sectional shape becomes circular arc shape, for example). It is assumed that the curved surface has a radius of curvature R. The straight pipe portion 3 is a portion in which the inner wall surface of the bell mouth 20 is parallel to the rotation axis of the propeller fan 1 (parallel to the air flow direction) (hereinafter, the straight pipe portion in other members and the like). The same).

  Moreover, the diffuser part 4 which becomes a blowing opening part generally is a part opened in order to blow out air in the downstream (blowing side) of the bell mouth 20. Also in the diffuser portion 4, the distance between the rotation shaft of the propeller fan 1 and the terminal portion of the blowout opening 2 (the diameter of the opening portion) is the distance between the rotation shaft and the surface of the straight pipe portion 3 (straight pipe). Longer than the diameter of the portion 3). And the inner wall surface from the blower side end (diffuser part 4 suction side end) of the straight pipe part 3 to the diffuser part 4 blower side end is a slope having an expansion, and the cross-sectional shape becomes a taper shape (a trumpet shape). It is formed as follows. Here, although the bell mouth 20 of the present embodiment has the straight pipe portion 3, the inner wall surface may be formed by the suction opening portion 2 and the diffuser portion 4, for example.

  FIG. 2 is a diagram illustrating an example of the outdoor unit 6 that houses the blower according to Embodiment 1 of the present invention. In the outdoor unit 6 in FIG. 2, the propeller fan 1 is installed in the housing so as to form an air flow (upward blowing) in the direction opposite to the vertical direction. The fan guard 5 avoids contact between the propeller fan 1 and other objects, prevents damage to both, and performs protection.

  FIG. 3 is a diagram illustrating another example of the outdoor unit 6 that houses the blower according to Embodiment 1 of the present invention. In the outdoor unit 6 of FIG. 3, as shown in FIG. 3A, the propeller fan 1 is installed in the casing so as to form an air flow (horizontal blowing) directed in the horizontal direction. In FIG.3 (b), the compressor 7 suck | inhales a refrigerant | coolant, compresses and discharges it in a high temperature and high pressure state. Although it does not specifically limit, For example, it can comprise with the compressor which controls rotation speed by an inverter circuit etc. and can adjust the discharge amount of a refrigerant | coolant. The outdoor heat exchanger 8 has heat transfer tubes and fins, and exchanges heat between outdoor air (outside air) that flows into the outdoor unit 6 by rotation of the propeller fan 1 and refrigerant that flows through the heat transfer tubes, for example, Cooling from the refrigerant (heat radiation to the outside air) or heat radiation to the refrigerant (heat absorption from the outside air) is performed.

  In the outdoor unit 6 shown in FIGS. 2 and 3 configured as described above, when noise is measured at various positions 1 m away from the outdoor unit, both of the outdoor units 6 have fan rotation shafts from the center of the fan guard 5. It was found that the noise was highest at a position 1 m away from the upper downstream side. The reason for this will be described below.

  FIG. 4 is a diagram showing a trajectory line coming out from the blade surface of the propeller fan 1. 4A shows a trajectory line when the straight pipe portion 3 of the bell mouth 20 is long, and FIG. 4B shows a trajectory line when the straight pipe portion 3 is short. In FIG. 4A and FIG. 4B, the blade tip vortex 10 is generated. The blade tip vortex 10 has a flow from the pressure surface toward the suction surface due to the pressure difference between the pressure surface (the leeward blade surface) and the suction surface (the windward blade surface) at the outer peripheral end of the propeller fan 1. Has a vortex structure. This causes a static pressure fluctuation on the blade surface of the propeller fan 1 and becomes a noise source.

FIG. 5 is a diagram showing a distribution of rms values of static pressure fluctuations on the bellmouth wall surface. FIG. 5 shows the distribution of the rms value of the static pressure fluctuation in the bell mouth 20 based on the flow represented by the trajectory line of FIG. The larger this value, the greater the noise generated from the bellmouth wall. The definition relating to the rms value of the static pressure fluctuation is as expressed by the following equation (1). Here, the static pressure is set to p _s (t) = p _sa + p _s ′ (t) (p _sa : average value, p _s ′ (t): fluctuation value).

  Accordingly, the noise associated with the rotation of the propeller fan 1 is generated when the blade tip vortex 10 increases the static pressure fluctuation on the blade surface of the propeller fan 1 or the wall surface of the bell mouth, and the noise source is the outer peripheral side of the blade surface of the propeller fan 1 or It becomes the bellmouth wall. For this reason, in the outdoor unit 6 shown in FIGS. 2 and 3, neither outdoor unit 6 has a wall surface that blocks sound measured at a position 1 m downstream from the center of the fan guard 5 on the fan rotation axis. , Get the biggest.

FIG. 6 is a diagram illustrating an outline of a blower including the sound insulating plate 13 according to the first embodiment. In FIG. 6, the sound insulation plate 13 and the like are represented by a cross section. The blower of the present embodiment is provided with a sound insulating plate 13 for reducing noise. Here, the sound insulating plate 13 prevents the outer peripheral end of the propeller fan 1 and the straight pipe portion 3 of the bell mouth 20 from being visible from the central portion of the fan guard 5 (for convenience of description in FIG. 6 and the like, The sound insulating plate 13 is shown short). Further, the diffuser straight pipe portion 17 is a straight pipe portion located at a portion on the leeward side in the diffuser portion 4. Here, the shortest distance between the propeller fan 1 and the sound insulating plate 13 with respect to the direction of air flow is H ₁ . Further, the height of the sound insulating plate 13 (the length in the air flow direction) is H ₂ .

FIG. 7 is a view showing the sound insulating plate 13. In FIG. 7, the sound insulating plate 13 is represented by a cross section. The sound insulating plate 13 includes an upwind straight pipe section 14, an S-shaped section 15 that is a curved pipe section for connecting (connecting) the upwind straight pipe section 14 and the downwind straight pipe section 16, and the downwind straight pipe section 16. Have. Here, when the diameter of the leeward straight pipe portion 14 is D ₁ , the diameter of the leeward straight pipe portion 16 is D ₂ , and the diameter of the propeller fan 1 is D, the relation of D ₁ <D <D ₂ is satisfied. Shall.

  FIG. 8 is a diagram for explaining a method of fixing the sound insulating plate 13 and the like. As shown in FIG. 8A, for example, a plurality of thin ribs 18 coupled to the leeward straight pipe portion 16 may be fixed to the fan guard 5 by screws. Here, for example, the ribs 18 can be fitted and fixed to the fan guard 5. Further, as shown in FIG. 8B, the leeward straight pipe portion 16 of the sound insulating plate 13 may be fixed by screwing to a rib 19 connected to the fan guard 5. Here, for example, the sound insulating plate 13 can be fitted and fixed to the rib 19.

FIG. 9 is a diagram for explaining a PWL measurement method called a 10-point method. In the conventional JIS standard or the like, the noise value at one point away from the outdoor unit by a predetermined position is used. However, in recent years, the noise value using PWL (power level) is being changed. PWL (dB) is expressed by the following equation (2). Here, SPL _i is a noise value (dB) at the positions of points S _{1 to} S ₁₀ , and N is a measurement point. In the 10-point method, N = 10 because there are 10 measurement points.

Here, in the blower of FIG. 6, D ₁ = 690 mm, D ₂ = 710 mm, D = 700 mm, H ₁ = 60 mm, H ₂ = 70 mm, and the thickness of the sound insulating plate 13 is 2 mm. This blower is mounted on the outdoor unit 6 shown in FIG. 2, and the PWL (dB) and fan input (W) measured by the 10-point method when the air volume passing through the fan guard 5 is 200 m ³ / min, Table 1 shows the cases with and without.

The PWL in equation (2) depends greatly on the largest SPL _i value. In FIG. 9, the noise value at the point S ₁ corresponding to the position directly above the propeller fan 1 is the largest. This is because when the noise source is the outer peripheral end of the propeller fan 1 and the wall surface of the bell mouth 20 (bell mouth wall surface) is the noise source, there is no wall surface to be sound-insulated between the noise source and the point S _1. .

  From Table 1, it can be seen that the sound insulating plate 13 is insulating the noise generated from the outer peripheral side of the blade surface and the bell mouth wall surface. Moreover, since the input increase to the propeller fan 1 is slight, it can be seen that the increase in ventilation resistance by the sound insulating plate 13 is small. This is because the wind direction by the propeller fan 1 is almost parallel to the straight pipe portion 3 and the wind gently changes the direction of the wind at the S-shaped portion 15, so that it is not separated and the ventilation resistance is small.

As described above, the blower of the present embodiment includes the sound insulating plate 13 having the upwind straight pipe portion 14, the leeward straight pipe portion 16, and the S-shaped portion 15, which are parallel to the straight pipe portion 3 of the bell mouth 20. , D ₁ <D <D ₂ , the noise generated from the outer peripheral side of the blade surface of the propeller fan 1 and the bell mouth wall surface can be shielded, and the fan guard 5 is positioned at a position in the leeward direction. Noise can be suppressed.

Embodiment 2. FIG.
FIG. 10 is a diagram for explaining a blower according to Embodiment 2 of the present invention. In the blower of FIG. 6, D ₁ = 690 mm, D ₂ = 710 mm, D = 700 mm, H ₂ = 70 mm, and the thickness of the sound insulating plate 13 is 2 mm. FIG. 10 shows the relationship between PWL and H ₁ (H ₁ / D) when this blower is mounted on the outdoor unit 6 of FIG. 2 and the air volume passing through the fan guard 5 is 200 m ³ / min. Here, the length of the diffuser straight pipe portion 17 is also changed by the amount H ₁ is changed.

From FIG. 10, when H ₁ /D=0.007 and H ₁ /D<0.007, PWL increases (noise increases) as the value of H ₁ / D decreases. When H ₁ /D≧0.007, PWL is substantially constant. This is a noise source because when the position of the windward straight pipe portion 14 is close to the propeller fan 1, the static pressure fluctuation on the wall surface near the propeller fan 1 of the windward straight pipe portion 14 becomes large. This is because if the windward straight pipe portion 14 is separated from the propeller fan 1, the static pressure fluctuation on the wall surface near the propeller fan of the windward straight pipe portion 14 becomes small, and it does not become a noise source.

Therefore, in the blower of the present embodiment, the noise positioned in the leeward direction from the center of the fan guard 5 is reduced by defining the positional relationship of the blower so that H ₁ ≧ 0.007D. And the overall noise can be reduced. Here, when H ₁ /D≧0.007, PWL is almost constant, and even if H ₁ becomes longer, the noise reduction effect does not change substantially. Therefore, although the upper limit of the value of H ₁ / D is not particularly specified, it can be done. As long as it is as close to 0.007, the outdoor unit 6 can be downsized.

Embodiment 3 FIG.
FIG. 11 is a view for explaining a blower according to Embodiment 3 of the present invention. In the blower of FIG. 6, D ₁ = 690 mm, D ₂ = 710 mm, D = 700 mm, H ₁ = 60 mm, and the thickness of the sound insulating plate 13 is 2 mm. FIG. 11 shows the relationship between PWL and H ₂ (H ₂ / D) when this blower is mounted on the outdoor unit 6 of FIG. 2 and the air volume passing through the fan guard 5 is 200 m ³ / min. Here, the length of the diffuser straight pipe portion 17 is also changed by the amount of change of H ₂ .

From FIG. 11, when H ₂ /D=0.04 and H ₂ /D<0.04, as the value of H ₂ / D decreases, PWL increases (noise increases). When H ₂ /D≧0.04, PWL is almost constant. This is because, for example, when H ₂ /D<0.04, the air blown out by the propeller fan 1 does not flow along the sound insulation plate 13, and peeling occurs on the wall surface on the sound insulation plate 13. Become. On the other hand, in the case of H ₂ /D≧0.04, the air blown out by the propeller fan 1 gradually changes, flows along the sound insulation plate 13 and does not peel off on the wall surface, and generates ventilation resistance. This is because it is suppressed.

Therefore, in the blower of the present embodiment, the noise located in the leeward direction from the center of the fan guard 5 can be reduced by setting the height of the sound insulating plate 13 to be H ₂ ≧ 0.04D. The overall noise can also be reduced. Here, when H ₂ /D≧0.04, PWL is substantially constant, and even if H ₂ becomes longer, the noise reduction effect does not change substantially. Therefore, although the upper limit of the value of H ₂ / D is not particularly specified, it can be done. As long as it is as close to 0.04 as possible, the outdoor unit 6 can be downsized.

Embodiment 4 FIG.
FIG. 12 is a view for explaining a blower according to Embodiment 4 of the present invention. In the blower of FIG. 6, D ₂ = 710 mm, D = 700 mm, H ₁ = 60 mm, H ₂ = 70 mm, and the thickness of the sound insulating plate 13 is 2 mm. FIG. 12 shows the relationship between PWL and (D ₂ −D ₁ ) / D when this blower is mounted on the outdoor unit 6 of FIG. 2 and the air volume passing through the fan guard 5 is 200 m ³ / min. .

From FIG. 12, the value of (D ₂ -D ₁ ) / D is small when (D ₂ -D ₁ ) /D=0.03 and (D ₂ -D ₁ ) / D <0.03. The more (D ₁ becomes larger), the PWL becomes larger (noise becomes larger). In the case of (D ₂ −D ₁ ) /D≧0.03, PWL is almost constant. This is because, for example, when (D ₂ −D ₁ ) / D <0.03, the air blown out by the propeller fan 1 does not flow along the sound insulation plate 13, and peeling occurs on the wall surface on the sound insulation plate 13. This is ventilation resistance. On the other hand, in the case of (D ₂ −D ₁ ) /D≧0.03, the air blown out by the propeller fan 1 is gently turned and flows along the sound insulating plate 13 so that no separation occurs on the wall surface. This is because the occurrence of ventilation resistance is suppressed.

Therefore, in the blower according to the present embodiment, D ₂ −D ₁ ≧ 0.03D ((D ₂ −D ₁ ) /D≧0.03) so that the leeward from the center of the fan guard 5 The noise located in the direction can be reduced, and the overall noise can also be reduced.

Embodiment 5 FIG.
13 is a block diagram of a refrigeration air conditioning apparatus according to Embodiment 5 of the present invention. In the present embodiment, a refrigeration air conditioner will be described as an example of a refrigeration cycle apparatus having the outdoor unit 6 described above. The refrigeration air conditioner of FIG. 13 includes the above-described outdoor unit (outdoor unit) 6 and load unit (indoor unit) 200, which are connected by a refrigerant pipe and are referred to as a main refrigerant circuit (hereinafter referred to as a main refrigerant circuit). ) To circulate the refrigerant. Among the refrigerant pipes, a pipe through which a gaseous refrigerant (gas refrigerant) flows is referred to as a gas pipe 300, and a pipe through which a liquid refrigerant (liquid refrigerant, which may be a gas-liquid two-phase refrigerant) flows is referred to as a liquid pipe 400.

  In the present embodiment, the outdoor unit 6 includes each device (means) of the compressor 7, the outdoor heat exchanger 8, the four-way valve 102, the outdoor blower 104, and the outdoor control device 105 described in the above embodiment. ).

  The compressor 7 compresses and discharges the sucked refrigerant as described above. Further, as described above, the outdoor heat exchanger 8 performs heat exchange between the refrigerant and air (outdoor air). Here, the outdoor heat exchanger 8 of the present embodiment functions as an evaporator, for example, during heating operation, performs heat exchange between the low-pressure refrigerant flowing from the liquid pipe 400 and the air, and evaporates the refrigerant. Let it vaporize. Moreover, it functions as a condenser during the cooling operation, and performs heat exchange between the refrigerant and air compressed in the compressor 7 flowing in from the four-way valve 102 side, thereby condensing and liquefying the refrigerant. In addition, the outdoor heat exchanger 8 is provided with the blower described in Embodiments 1 to 4 as the outdoor blower 104 in order to efficiently exchange heat between the refrigerant and the air. Here, for the outdoor blower 104, the rotational speed of the propeller fan 1 may be finely changed by arbitrarily changing the operating frequency of the fan motor by the inverter device.

  The four-way valve 102 switches the refrigerant flow between the cooling operation and the heating operation based on an instruction from the outdoor control device 105. Moreover, the outdoor side control apparatus 105 consists of a microcomputer etc., for example. It is possible to perform wired or wireless communication with the load-side control device 204. For example, based on data relating to detection by various detection means (sensors) in the refrigeration air conditioner, operation frequency control of the compressor 7 by inverter circuit control, etc. Then, the respective units related to the refrigeration air conditioner are controlled to control the operation of the entire refrigeration air conditioner.

  On the other hand, the load unit 200 includes a load side heat exchanger 201, a load side expansion device (expansion valve) 202, a load side blower 203, and a load side control device 204. The load side heat exchanger 201 performs heat exchange between the refrigerant and air. For example, it functions as a condenser during heating operation, performs heat exchange between the refrigerant flowing in from the gas pipe 300 and air, condenses and liquefies the refrigerant (or gas-liquid two-phase), and moves to the liquid pipe 400 side. Spill. On the other hand, during the cooling operation, it functions as an evaporator, performs heat exchange between the refrigerant and the air whose pressure is reduced by the load-side throttle device 202, causes the refrigerant to take heat of the air, evaporates it, and vaporizes it. It flows out to the piping 300 side. In addition, the load unit 200 is provided with a load-side blower 203 for adjusting the flow of air for heat exchange. The operating speed of the load-side fan 203 is determined by, for example, user settings. The load side expansion device 202 is provided to adjust the pressure of the refrigerant in the load side heat exchanger 201 by changing the opening degree.

  The load-side control device 204 is also composed of a microcomputer or the like, and can communicate with the outdoor-side control device 105 by wire or wireless, for example. Based on an instruction from the outdoor control device 105 and an instruction from a resident or the like, for example, each device (means) of the load unit 200 is controlled so that the room has a predetermined temperature. Further, a signal including data related to detection by the detection means provided in the load unit 200 is transmitted.

  As described above, in the refrigeration air conditioning apparatus of the fifth embodiment, the noise of the outdoor unit 6 can be suppressed by using the blower described in the first to fourth embodiments as the outdoor blower 104 for the outdoor unit 6. .

  DESCRIPTION OF SYMBOLS 1 Propeller fan, 2 Suction opening part, 3 Straight pipe part, 4 Diffuser part, 5 Fan guard, 6 Outdoor unit, 7 Compressor, 8 Outdoor heat exchanger, 10 wing tip vortex, 13 Sound insulation board, 14 Upwind direct Pipe part, 15 S-shaped part, 16 leeward side straight pipe part, 17 diffuser straight pipe part, 18, 19 rib, 20 bell mouth, 102 four-way valve, 104 outdoor fan, 105 outdoor control device, 200 load unit, 201 Load side heat exchanger, 202 load side throttle device, 203 load side blower, 204 load side control device, 300 gas piping, 400 liquid piping.

Claims (7)

A propeller fan having a plurality of blades that rotate around a rotation axis to generate a gas flow;
A straight pipe portion that is a cylindrical wall surface on the outside of the outer peripheral end of the blade along the rotation direction of the blade of the propeller fan, a blow-off side opening portion that is a gas blow-out side and a suction side from the straight pipe portion Forming a wall that constitutes the suction side opening, and a bell mouth for rectifying the gas;
A fan guard having a lattice covering the outlet side opening of the bell mouth;
A wall surface connecting a cylindrical windward straight pipe portion and a leeward straight pipe portion parallel to the straight pipe portion of the bell mouth with a substantially S-shaped curved pipe portion; and the fan guard, the propeller fan, A blower comprising a sound insulation plate attached between the two. The diameter D of the propeller fan, the diameter D _{1 of} the leeward straight pipe portion, and the diameter D ₂ of the leeward straight pipe portion satisfy a relationship of D ₁ <D <D _2. The blower described. 3. The blower according to claim 1, wherein a relationship of H ₁ ≧ 0.007D is established with respect to the diameter D of the propeller fan and the shortest distance H ₁ between the propeller fan and the sound insulating plate. When the diameter D of the propeller fan, the height of the sound insulation plate was H _2, blower according to claim 1, characterized in that a relation of H ₂ ≧ 0.04D. The diameter D of the propeller fan, the diameter D _{1 of} the leeward straight pipe portion, and the diameter D ₂ of the leeward straight pipe portion have a relationship of (D ₂ −D ₁ ) /D≧0.03. The blower according to any one of claims 1 to 4. A compressor for compressing the refrigerant;
An outdoor heat exchanger for exchanging heat between refrigerant and air;
An outdoor unit comprising the blower according to any one of claims 1 to 5. A load unit having a plurality of load-side heat exchangers for exchanging heat between the heat exchange object and the refrigerant, and a load-side expansion device for adjusting the pressure of the refrigerant flowing into the load-side heat exchanger;
A refrigeration cycle apparatus comprising a refrigerant circuit connected by piping to the outdoor unit according to claim 6.