JP3813356B2 - Heat exchanger using centrifugal blower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger using a centrifugal air blowing means, and more particularly to a heat exchanger using a centrifugal air blowing means in which noise generation is suppressed and efficiency is improved.
[0002]
[Prior art]
In air conditioning equipment and the like, various blowers are used to exchange heat by sending air into a heat exchanger. One such blower uses a centrifugal fan. Therefore, a conventional heat exchanger using a centrifugal fan will be described with reference to FIGS. The heat exchanger shown in both drawings is a portion corresponding to an indoor unit of a so-called packaged air conditioner. Here, FIG. 3 shows a cross-sectional perspective view of a heat exchanger using a conventional centrifugal fan, and FIG. 4 is a cross-sectional view of the heat exchanger shown in FIG.
[0003]
The indoor unit 1 is connected to an outdoor unit (not shown) to constitute a series of refrigeration cycles or heating cycles. In the casing 22 of the indoor unit 1, an impeller 2 that rotates around the rotation shaft 5 by a rotation drive motor M is provided. The impeller 2 has a hub 6 to which a rotational driving force is transmitted by a rotary shaft 5. A ring-shaped shroud 4 having an air intake opening 10 is provided near the center so as to face the hub. In the outer peripheral part between the shroud 4 and the hub 6, a plurality of blower blades 8 arranged at predetermined intervals in the circumferential direction are provided, which is called a centrifugal fan.
[0004]
A heat exchanging portion 13 is provided so as to surround the impeller 2 from the circumferential direction. The heat exchanging portion 13 is provided with a refrigerant pipe 16 and a plurality of fins 14 for flowing the refrigerant. In addition, a suction grill 20 and a blow-out grill 18 are provided in a casing 22 in which the impeller 2 and the heat exchange unit 13 are disposed. And this indoor unit is normally embedded in the ceiling.
[0005]
Next, the operation will be described. By the rotation of the impeller 2 in the direction of the arrow 3, indoor air is taken into the indoor unit 1 from the suction grill 20. The air taken into the indoor unit 1 is taken into the impeller 2 from the air intake 10, and is sent out between the hub 6 and the shroud 4 to the outer peripheral portion of the impeller 2 by the blower blades 8. The air sent to the outer peripheral side of the impeller 2 flows between the plurality of fins 14 arranged in the refrigerant pipe 16. At this time, heat exchange is performed between the air and the refrigerant. The air subjected to heat exchange is sent out from the blow grill 18 into the room. As described above, indoor cooling or heating is performed.
[0006]
[Problems to be solved by the invention]
However, the heat exchanger using the centrifugal fan described above has the following problems.
[0007]
As described above, the rotation shaft 5 of the impeller 2 is rotated by the rotation drive motor M and the rotation drive force is transmitted to the hub 6. Therefore, conventionally, a plurality of small holes N are provided in the hub 6 as shown in FIG. As a result, air taken into the impeller 2 from the air intake 10 passes between the shroud 4 and the hub 6, and flows out from the rear surface of the hub 6 through the small holes N to the surface by the action of the air flow 24. An air flow Fa is generated. Then, since the space surrounded by the housing 22 and the hub 6 is decompressed by the air flow Fa, an air flow Fb flowing from the gap between the housing 22 and the hub 6 is generated, and the air flow F flowing on the rear surface of the hub is generated. The drive motor M is cooled by this air flow F (see FIG. 5).
[0008]
However, there is such a small hole N for cooling the drive motor because of the generation of fluid noise due to the air flow F and the sound on the back surface of the hub 6 being easily transmitted to the outside through the small hole N of the hub 6. It has been experimentally confirmed that the noise value is higher than that in the case where no small hole N is provided.
[0009]
The present invention has been made to solve the above-described problems, and provides a heat exchanger using a centrifugal air blowing means that does not raise the temperature of a drive motor during operation and reduces noise. Objective.
[0010]
[Means for Solving the Problems]
The present invention is provided with a centrifugal blower means for taking in air from the central portion and sending the taken air to the surroundings by rotation of an impeller around a rotation axis, and to surround the centrifugal blower means for flowing a refrigerant. A heat exchanging means including a plurality of fins provided in the pipe, a drive motor for transmitting a rotational driving force to the impeller of the centrifugal air blowing means, and the centrifugal air blowing means and the heat exchanging means. And the drive motor is disposed outside the housing.
[0011]
By using this configuration, all the air sent out from the impeller flows to the heat exchange means side, and no air flow for cooling the drive motor is generated as in the conventional case, and noise resulting therefrom is generated. I don't have to.
[0012]
In addition, since the drive motor is disposed outside the housing, there is no risk of high temperatures during operation due to heat dissipation by the outside air.
[0013]
Specifically, the impeller includes a hub to which a rotational driving force from the drive motor is transmitted, and a ring-shaped shroud provided to face the hub and having an air intake opening near the center. A plurality of blower blades arranged at predetermined intervals in the circumferential direction at an outer peripheral portion between the shroud and the hub, and the drive motor is disposed outside the casing on the back side of the hub. It is characterized by being.
[0014]
By using this configuration, the drive motor is disposed outside the housing on the back side of the hub. For example, when used as an indoor unit of a packaged air conditioner built in the ceiling, the drive sound of the drive motor is There is no leakage from the body into the room.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
A heat exchanger using a centrifugal blower according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of a heat exchanger using a centrifugal blower according to an embodiment of the present invention.
[0016]
Referring to FIG. 1, an impeller 2 that rotates around a rotation shaft 5 by a drive motor M is provided in a housing 22 of the indoor unit 1. The impeller 2 has a hub 6 to which a rotational driving force is transmitted by a rotary shaft 5. A ring-shaped shroud 4 having an air intake opening 10 is provided near the center so as to face the hub 6. A centrifugal fan as a centrifugal blowing means is configured including the impeller 2 and the drive motor M.
[0017]
Further, the housing 22 has a suction grill 20 for taking in indoor air, a bell mouth 9 for guiding the air taken into the housing 22 to the air intake 10 of the centrifugal fan, and heat-exchanged air inside the housing 22 A blow-out grill 18 is provided for sending out to the top.
[0018]
A heat exchanging portion 12 as heat exchanging means is provided so as to surround the impeller 2 from the circumferential direction. The heat exchange unit 12 is provided with a pipe 16 and a plurality of fins 14 for flowing a refrigerant.
[0019]
A drive motor M is provided outside the housing 22 of the indoor unit 1. Thus, since the drive motor M is installed outside the housing 22, the drive motor M is cooled by a natural heat radiation action by the outside air. In this embodiment, the drive motor M is cooled by natural heat radiation by the outside air. However, when further cooling is required, a simple fan is provided on the side opposite to the hub 6 to drive the drive motor M. The fins may be rotated by the driving force to radiate heat.
[0020]
Next, the operation of the heat exchanger using the above-described centrifugal blower will be described. The rotation of the impeller 2 in the direction of arrow 3 allows indoor air to be taken into the indoor unit 1 from the suction grill 20 and taken into the impeller 2 from the air intake 10. The air taken into the impeller 2 is sent out to the outer periphery of the impeller 2 by the blower blades 8. And all the air sent out from the impeller 2 is sent to the heat exchange part 12 side, and the heat-exchanged air is sent out indoors through the blow grill 18.
[0021]
Thus, since the small hole N for cooling the drive motor M is not provided in the hub 6 as in the conventional device described above, there is no air flow for cooling the drive motor M in the housing 22. There is no noise caused by it. Further, since the drive motor M is disposed outside the housing 22 on the back side of the hub 6, that is, in the ceiling, the drive sound of the drive motor M may leak from the housing 22 into the room below the blowout grill 18. Absent.
[0022]
FIG. 2 shows the results of indoor noise measurement in the indoor unit of the packaged air conditioner using the heat exchanger according to the embodiment of the present invention and the indoor unit of the packaged air conditioner using the conventional heat exchanger (JIS standard “blower and Compressor-Noise level measurement method B 8346 "). In FIG. 2, the horizontal axis represents the rotational speed of the impeller 2 and the vertical axis represents the sound pressure level (SPL) indicating the noise value.
[0023]
As is apparent from FIG. 2, in the case of the heat exchanger of the present invention, it can be seen that the noise value is lower at the rotational speed of each impeller 2 than in the conventional apparatus.
[0024]
The above description of the embodiment is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. The configuration of each part of the present invention is not limited to the above-described embodiment, and various modifications can be made within the technical scope described in the claims.
[0025]
【The invention's effect】
As described above, according to the present invention, it is possible to reduce the noise as compared with the conventional apparatus without increasing the temperature of the drive motor during operation.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a heat exchanger using centrifugal air blowing means according to an embodiment of the present invention.
2 is a diagram showing indoor noise measurement results in the indoor unit of the packaged air conditioner using the heat exchanger of FIG. 1 and the indoor unit of the packaged air conditioner using the heat exchanger of FIG. 4;
FIG. 3 is a cross-sectional perspective view of a heat exchanger using a conventional centrifugal fan.
4 is a cross-sectional view of the heat exchanger of FIG.
5 is a partial enlarged cross-sectional view for explaining the flow of air sent out from the impeller 2 of the heat exchanger of FIG. 3; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Indoor unit 2 Impeller 3 Rotation direction 4 Shroud 5 Rotating shaft 6 Hub 8 Blower blade 9 Bell mouth 10 Air intake 12 Heat exchange part 14 Fin 16 Refrigerant piping 18 Blowing grill 20 Suction grill 22 Case 24 Air flow

Claims (2)

Centrifugal blowing means that takes in air from the center and sends the taken-in air to the surroundings by rotation of the impeller around the rotation axis;
A heat exchanging means that is provided so as to surround the centrifugal air blowing means and includes a pipe for flowing a refrigerant and a plurality of fin portions provided in the pipe;
A drive motor that transmits rotational driving force to the impeller of the centrifugal air blowing means;
A housing having the centrifugal air blowing means and the heat exchange means inside,
A heat exchanger using centrifugal air blowing means, wherein the drive motor is disposed outside the housing. The impeller includes a hub to which a rotational driving force from the drive motor is transmitted, a ring-shaped shroud provided to face the hub and having an air intake opening near the center, and the shroud and the hub. Having a plurality of blower blades arranged at a predetermined interval in the circumferential direction on the outer peripheral portion between,
2. The heat exchanger using centrifugal air blowing means according to claim 1, wherein the drive motor is disposed outside the housing on the back side of the hub.

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