JP2011085341A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure a heat transfer area by using heat exchanger fins and to reduce interference sound generated at end sections of the heat exchanger fins in a ceiling-embedded air conditioner indoor unit. <P>SOLUTION: A heat exchanger 2 including a plurality of heat transfer tubes 11 and the plurality of thin plate-shaped fins 10, has straight sections and bent sections so that it is disposed at a downstream side in the air distributing direction in a state of surrounding an outer side of a blower 1, the thin plate-shaped fins 10 have recessed sections 12 on front edge sections positioned at an upstream side in the air distributing direction, the recessed sections 12 of the fins are disposed on positions separating from adjacent heat transfer tubes disposed in the vertical direction at the upstream side in the air distributing direction, bottom faces of the recessed sections are positioned at the upstream side in the air distributing direction, with respect to the heat transfer tubes disposed in the vertical direction at the upstream side in the air distributing direction, and as the fins 10 having the recessed sections 12 are disposed on the straight sections or the bent sections, or the whole of the heat exchanger, a heat radiation area can be efficiently ensured, and the noise around the heat exchanger can be reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to the structure of a heat exchanger for a separate type ceiling cassette embedded air conditioner indoor unit, and more particularly to the shape and arrangement of fins constituting the heat exchanger. In the following description, a ceiling cassette embedded type air conditioner will be described, but the present invention is naturally applicable not only to a cassette type but also to a ceiling embedded type air conditioner.

  The prior art in the air flow path of the ceiling cassette-embedded air conditioner will be described below with reference to FIGS. FIG. 8 is a diagram for explaining a separation vortex generated at the fin end in a normal ceiling cassette embedded air conditioner. FIG. 9 is a diagram for explaining the flow of air flowing from the suction port—the finned heat exchanger—the blowout port in a normal ceiling cassette embedded air conditioner.

  In many cases, the air flow path structure of the indoor unit in the ceiling cassette-embedded air conditioner is arranged so that the air sucked from the suction port 5 by the blower 1 placed in the center of the cassette surrounds the outside of the blower 1 immediately. The air that has been blown to the heat exchanger 2 and heat-exchanged there changes the direction of the wind downward on the side wall surface 9 of the cabinet, and is then blown into the room from the blowout port 6. In particular, since the heat exchanger 2 that has a large ventilation resistance and is one of the causes of noise is installed near the outlet, the noise during ventilation to the heat exchanger 2 is easily leaked into the room as it is.

  Further, as shown in FIG. 8, the fins 10 constituting the heat exchanger 2 are basically arranged substantially at right angles to the rotation direction of the blower 1 and are blown from the blower 1 to the fins 10 of the heat exchanger 2. The flow flows into the fin 10 at a certain angle of attack, so that a flow separation vortex 15 is generated at the end of the fin 10, and interference pressure may be generated between the fins 10 due to the pressure fluctuation. . This phenomenon is often observed particularly when the blower 1 and the heat exchanger 2 are installed close to each other, and in order not to generate interference noise, the distance between the blower 1 and the heat exchanger 2 must be sufficiently large. Is required.

  However, due to the recent importance of compactness and improved performance of cassettes, there is a situation in which the distance between the fan 1 and the heat exchanger 2 cannot always be ensured by design. As a result, the above-described interference noise becomes a large noise. Leaks into the room, which significantly impairs comfort during driving. For this reason, various improvements have been studied for reducing noise in the heat exchanger structure of an air conditioner indoor unit embedded in a ceiling cassette.

  As a conventional technique for a heat exchanger of a ceiling cassette-embedded air conditioner indoor unit, for example, as shown in Patent Document 1, by projecting a wind direction guide plate that guides the air flow to the heat exchanger fins, It is disclosed to prevent the interference sound caused by the separation vortex 15 described above. According to this, the angle of attack of the blown air flowing into the fin can be suppressed by projecting the wind direction guide plate inclined toward the rotation direction of the blower at the upstream end of the arbitrary fin, as described above. It is described that the interference sound caused by the peeling vortex 15 can be suppressed.

  In addition, as another conventional technique, for example, in Patent Document 2, a fin having a wind guide portion that is inclined in the opposite direction to the rotation direction of the blower is provided at the upstream end portion as a whole heat exchanger or every arbitrary number of sheets. It is disclosed to prevent the occurrence of clogging or a strange odor at the tip of the fin. According to this, it is possible to prevent dirt particles such as dust, oil, and smoke contained in the blown air from adhering and accumulating on the tip of the fin by smoothly flowing the blown air into the fin. is described.

JP 2000-161694 A JP-A-5-215358

  In the prior arts of Patent Documents 1 and 2 described above, a fin that has a wind direction guide plate and a wind guide part for smoothly flowing the blown air at the upstream end is provided on a part or the whole of the heat exchanger. By installing it, it is intended to prevent the occurrence of interference noise, clogging, and offensive odor due to the separation vortex at the tip of the fin.

  However, in the structure proposed in Patent Document 1, since a bent plate-shaped airflow direction guide plate is sandwiched between fins, the airflow direction guide is only between specific fins from the viewpoint of ventilation. A board cannot be provided. For this reason, there may be a problem that the air blowing guide effect is not sufficient between the fins that are not provided with the wind direction guide plate and are located in a range away from the wind direction guide plate. Moreover, since the wind direction guide plate receives the blown air from the blower at a close distance and in a substantially right angle direction, there is a concern about the influence of the collision loss on the blowing performance. Furthermore, the fin located on the back side of the inclined portion in the wind direction guide plate is just a shadow of the flow, and a sufficient ventilation cannot be expected. In addition, there are still problems such as vibration isolation means for the wind direction guide plate itself, a stable fixing method, and an increase in the number of parts and the manufacturing process due to the addition of the wind direction guide plate.

  On the other hand, in the above-mentioned Patent Document 2, the wind guide portion is arranged substantially parallel to the blown air, and the wind guide portion is configured by extending and inclining the upstream side of the fin itself. A wind guide portion can be provided for all the fins, whereby the blown air can be smoothly rectified and flown between the fins. In addition, by arranging the fins having the air guide portion for each arbitrary number of sheets, the air guide pitch can be easily secured even for a heat exchanger having a small fin pitch specification.

  However, in any of the structures of Patent Document 2 and Patent Document 1 described above, bending processing is added to the conventional flat fin, and an increase in cost when manufacturing the fin is inevitable. Also, extending and bending the upstream side of the fin only for the role of the air blowing guide increases the airflow resistance between the fins and increases the fin area, which is not necessarily effective for heat transfer performance. There is concern about cost performance problems such as decline.

  Further, in particular, according to the above-mentioned Patent Document 2, it is possible to reduce the fin pitch at the air guide section and to arrange heat fins having the air guide section for any number of fins with a small fin pitch. Although it states that it can do, the subject that the addition of a fin bending process and the complexity of the process at the time of a fin arrangement | sequence may also be inevitable arises.

  Therefore, in the present invention, on the premise of actual commercialization, in consideration of product performance, productivity, and cost, specifically, in the ceiling embedded type air conditioner indoor unit, the heat transfer area by the heat exchanger fins It is an object of the present invention to provide a heat exchanger having a structure focused on reducing interference noise generated at the end portions of the heat exchanger fins.

In order to solve the above problems, the present invention adopts the following configuration.
In a separate type ceiling-embedded indoor unit comprising: a ceiling-embedded cabinet that houses a blower and a heat exchanger; and a ceiling-exposed panel in which a suction port and a blow-out port are arranged horizontally. Includes a plurality of heat transfer tubes and a plurality of thin plate-shaped fins attached substantially perpendicular to the tube direction of the plurality of heat transfer tubes, and the heat exchanger further includes a straight line in the tube direction. Are formed on the downstream side in the blowing direction of the blower so as to surround the outside of the blower, and the thin fins are arranged in the blowing direction. A recess cut out in a substantially rectangular shape at the front edge end located on the upstream side of the fin, and the recess of the fin is located at a site separated from adjacent heat transfer tubes arranged vertically on the upstream side in the blowing direction Be provided In addition, the bottom surface of the concave portion is positioned on the upstream side in the air blowing direction with respect to the heat transfer tubes arranged in the vertical direction on the upstream side in the air blowing direction, and the fins having the concave portions are installed in the linear portion of the heat exchanger. The configuration.

  Further, in the air conditioner, the fin having the recess is configured to be installed in the bent portion of the heat exchanger instead of being installed in the linear portion of the heat exchanger, and the fin having the recess is In addition, instead of being installed in the straight portion of the heat exchanger, the heat exchanger has a configuration in which it is installed in the entire portion including the straight portion and the bent portion, and further, a thin plate shape formed in the front edge end portion The concave portion of the fin is configured to form a symmetrical shape with the convex portion formed at the front edge end portion.

  According to the present invention, in a heat exchanger with fins composed of a straight portion and a bent portion, a blower and a heat exchanger are formed by forming a recess in which the front edge end of the fin in the straight portion is cut out in a substantially rectangular shape. Can be partially expanded, and the interference noise generated by installing the heat exchanger and the blower at a narrow interval can be reduced. Furthermore, by limiting the recess cut out in a substantially rectangular shape to the fin front edge end other than the end in the vicinity of the heat transfer tube, only the portion with relatively poor heat transfer performance is shaved, and heat exchange Performance degradation can be prevented as much as possible. Furthermore, by keeping the range of the recesses upstream from the heat transfer tubes arranged on the most upstream side in the air blowing direction, while keeping the increase in the length of the front edge of the fin that can cause separation vortices and interference noise small, Reduction of heat transfer area can be suppressed as much as possible.

  Moreover, in the bent part in the heat exchanger with fins, the fin pitch on the most upstream side of the bent part, which is narrower than the straight part by bending, is partially expanded by arranging the fin having the concave part on the front edge thereof. Therefore, it is possible to reduce the ventilation resistance when the blown air passes through the fins, which is larger than the straight portion.

  Moreover, by arranging the fins having the recesses over the entire straight portion and the bent portion of the heat exchanger, both advantages of the straight portion and the bent portion can be exhibited, and the noise and wind speed balance during blowing can be improved.

It is side sectional drawing which shows the suction inlet, the air blower, the heat exchanger with a fin, a water receptacle, a cabinet side wall, a blower outlet, and a ceiling exposure type | mold panel in the ceiling embedded type air conditioner which concerns on embodiment of this invention. In the ceiling-embedded air conditioner according to the present embodiment, it is a top cross-sectional view showing a blower, a heat exchanger provided with fins having a concave portion in a linear portion, a cabinet side wall, and a blowout port. In the ceiling-embedded air conditioner according to the present embodiment, it is a top cross-sectional view showing a blower, a heat exchanger provided with fins having concave portions in bent portions, a cabinet side wall, and a blowout port. In the ceiling-embedded air conditioner according to the present embodiment, it is a top cross-sectional view showing a blower, a heat exchanger provided with fins having recesses all around, a cabinet side wall, and a blowout port. It is a figure explaining the material taking example of the fin creation which has a recessed part in the ceiling embedded type air conditioner which concerns on this embodiment. It is a figure explaining the fin pitch in the bending part of the heat exchanger in the ceiling-embedded air conditioner which concerns on this embodiment. It is a figure explaining the ventilation flow in the bending part downstream side of the heat exchanger in the ceiling embedded type air conditioner concerning this embodiment. It is a figure explaining the separation vortex which generate | occur | produces in the fin edge part in a normal ceiling embedded type air conditioner. It is a figure explaining the ventilation flow in the normal ceiling-embedded air conditioner over a suction inlet-a heat exchanger with a fin-outlet.

  The structure of the indoor heat exchanger in the ceiling-embedded air conditioner according to the embodiment of the present invention will be described in detail below with reference to FIGS. In the drawings, 1 is a blower, 2 is a heat exchanger, 3 is a water receiver, 4 is a cabinet, 5 is a suction port, 6 is an outlet, 7 is a panel, 8 is a ceiling, 9 is a cabinet side wall, 10 is a fin, 11 is a heat transfer tube, 12 is a recess at the front edge of the fin cut out in a substantially rectangular shape, 13 is the direction of rotation of the blower, 16 is the direction of air flow, 17 is the pitch of the fin front edge near the heat transfer tube, and 18 is The pitch of the fin recessed bottom face edge part is represented, respectively. Hereinafter, examples which are specific examples of the ceiling-embedded air conditioner according to the present embodiment will be described.

"Example 1"
Example 1 of the ceiling-embedded air conditioner according to the present embodiment will be described with reference to FIGS. 1 and 2. A blower 1, a heat exchanger 2, a water receiver 3, a ceiling-embedded cabinet 4 for storing them, a suction port 5, a blow-out port 6, and a ceiling-exposed panel 7 in which these are horizontally disposed are provided. In a ceiling-embedded indoor unit of a separate type (a type in which an outdoor unit and an indoor unit are separated), the heat exchanger 2 includes a plurality of fins 10 and a plurality of heat transfer tubes 11 that vertically penetrate the fins 10. The heat exchanger 2 is disposed on the downstream side in the blowing direction of the blower 1 so as to have at least one bent portion and surround the outside of the blower 1.

  As illustrated in FIG. 2, the heat transfer tubes 11 and the fins 10 of the heat exchanger 2 are arranged so as to surround the outer periphery of the blower 1, and are composed of four straight portions and three bent portions in the illustrated example. 1 is a thin plate having a longitudinal direction (vertical direction on the paper surface: up and down arrows in FIG. 1), a width direction (horizontal direction on the paper surface), and a thickness direction (orthogonal direction on the paper surface) that is a fin pitch direction. The fins 10 are arranged so that the longitudinal direction of the fins 10 is substantially parallel to the rotation axis of the blower 1 (the direction of the rotation axis at a certain angle and the longitudinal direction of each fin, which is a thin plate-like body). Is done.

  And the fin 10 of the heat exchanger 2 arrange | positioned in a straight part in the present Example 1 is a ventilation direction upstream edge part (fin front edge), and other than the vicinity of the heat exchanger tube 11 (from adjacent heat exchanger tubes) The fin ends of the parts separated from each other have a recess 12 cut out in a substantially rectangular shape, and the end of the recess 12 on the downstream side in the blowing direction (the bottom surface of the recess) is on the most upstream side in the blowing direction. It is located upstream from the most upstream side in the air blowing direction of the arranged heat transfer tubes 11 (the heat transfer tubes in the left column in the illustrated example of FIG. 1) (distance L in FIG. 1).

  As shown in FIG. 1, the fin end portion is substantially rectangular in the straight portion excluding the bent portion in which the distance between the blower 1 and the heat exchanger 2 can be secured relatively large by forming the concave portion at the front edge of the fin 10 described above. The distance between the blower 1 and the heat exchanger 2 can be partially expanded by the amount cut out in the shape, and the interference sound generated by installing the blower 1 and the heat exchanger 2 at a narrow interval is reduced. Can do.

  Further, by limiting the recess 12 cut out in a substantially rectangular shape to fin ends other than the ends near the heat transfer tubes 11 (parts separated from the heat transfer tubes adjacent in the vertical direction), heat transfer performance Only the relatively bad part is cut away (the fin part moving away from the heat transfer tube has a lower temperature so that the heat radiation performance is worsened), and the deterioration of the heat exchange performance can be prevented as much as possible. Further, by keeping the range of the recess 12 upstream of the heat transfer tube 11 disposed on the most upstream side in the blowing direction, the length of the fin leading edge that may cause separation vortices and interference noises. While keeping the increase small (when the depth of the recess formed on the fin leading edge reaches the downstream side of the heat transfer tube, a separation vortex is generated corresponding to the length of that, and noise is generated thereby) The reduction in the heat transfer area of the fin 10 can be suppressed as much as possible.

"Example 2"
Example 2 of the ceiling-embedded air conditioner according to the present embodiment will be described with reference to FIGS. 3, 6, and 7. Example 2 of the air conditioner according to the present embodiment has a configuration in which the fin 10 having the recess 12 is arranged in the bent portion of the heat exchanger 2. As shown in FIG. 6, the fin pitch 17 inside the bent portion, which has become narrower than the straight portion due to the bending of the heat exchanger 2, becomes the fin pitch 18 on the bottom surface due to the formation of the recess, and the fin pitch is partially increased. Since it will spread, the ventilation resistance at the time of the fin 10 passage of the ventilation air 16 which was large compared with the linear part can be reduced.

  Further, because of the structure of the bent portion of the heat exchanger 2, as shown in FIG. 7, there is no outlet 6 on the downstream side of the bent portion, and the blown air 16 that has passed through the bent portion bypasses to the nearest outlet 6. Therefore, adopting the structure of Example 2 is very effective for improving the wind speed balance of the entire heat exchanger 2, Noise can be reduced without reducing the air volume.

"Example 3"
Example 3 of the ceiling-embedded air conditioner according to the present embodiment will be described with reference to FIG. In the air conditioner in FIG. 2 showing the first embodiment and FIG. 3 showing the second embodiment, the third embodiment has a configuration in which the fins 10 having the recesses 12 are arranged in the entire heat exchanger 2. With this configuration, the advantages of both Example 1 and Example 2 can be exhibited, and noise and wind speed balance during blowing can be improved. Furthermore, by unifying all the fins 10 into the same shape, it is not necessary to use the fins 10 at the straight line portion and the bent portion, and the production efficiency can be improved.

Example 4
Example 4 of the ceiling-embedded air conditioner according to the present embodiment will be described with reference to FIG. This Example 4 shows the manufacturing method of the fin 10 which has the recessed part 12 used for Examples 1-3 of the air conditioner which concerns on this embodiment. As shown in FIG. 5, the holes for the heat transfer tubes are provided in four rows in the vertical direction in the illustrated example, and at that time, the holes in the respective rows are shifted in the vertical direction by a half pitch in the thin plate-like fins 10, It is to cut into a concavo-convex shape as shown in the figure at the central portion in the vertical direction.

  At the time of this cutting, for example, the right fin is configured such that the concave portion and the convex portion are symmetrical with respect to the middle one-dot chain line in the figure (the same symmetrical shape is also applied to the left fin in the figure). By adopting such a manufacturing method in which the shape of the concave portion and the convex portion is symmetrical, the concave and convex shape of the fin end portion having the concave portion is not wasted when taking the material, and the cost can be suppressed.

  As described above, the air conditioner according to the embodiment of the present invention has the following configuration and has a function or an action. That is, in a separate-type ceiling cassette embedded indoor unit having a ceiling-embedded cabinet and a ceiling-exposed decorative panel arranged horizontally, the heat exchanger includes a plurality of fins and a plurality of transmission lines penetrating them vertically. It is composed of a heat pipe and is disposed downstream of the blower in the blowing direction so as to surround at least one bent portion and surround the outside of the blower. Direction) is arranged so as to be substantially parallel to the rotation axis of the blower, and the fins arranged on the straight portions other than the bent portion of the heat exchanger are the upstream ends of the blowing direction and in the vicinity of the heat transfer tubes The end of the recess other than the fin end is cut out into a substantially rectangular shape, and the end of the recess downstream in the blowing direction is upstream from the most upstream side in the blowing direction of the heat transfer tube arranged on the most upstream side in the blowing direction. The distance between the blower and the heat exchanger is partly cut out in a substantially rectangular shape except for the bent portion where the distance between the blower and the heat exchanger can be secured relatively large. The interference sound generated by installing the heat exchanger and the blower at a narrow interval can be reduced.

  Furthermore, by limiting the recesses cut out in a substantially rectangular shape to fin ends other than the ends in the vicinity of the heat transfer tubes, only the relatively poor portions of the heat transfer performance are shaved, and the heat exchange performance is reduced. A drop can be prevented as much as possible. Furthermore, by keeping the range of the recess on the upstream side of the most upstream side in the air flow direction of the heat transfer tube arranged on the most upstream side in the air blowing direction, it is possible to increase the length of the fin leading edge that can cause separation vortices and interference noise. It is possible to suppress the reduction of the heat transfer area of the fin as much as possible while keeping it small.

  In addition, by arranging fins with recesses in the bent part of the heat exchanger, the fin pitch inside the bent part, which was narrower than the straight part by bending, can be partially expanded, compared to the straight part Ventilation resistance when the blown air passes through the fins can be reduced. In addition, because of the structure of the ceiling cassette-embedded air conditioner indoor unit, there is no outlet on the downstream side of the bent part, and the blown air that has passed through the bent part must reach the nearest outlet, Ventilation resistance was higher than that of the straight part, and adopting a structure in which fins with recesses are arranged in the bent part of the heat exchanger is very effective in improving the overall wind speed balance of the heat exchanger, Noise can be reduced without reducing the air volume.

  Moreover, by arranging the fins having the recesses in the entire heat exchanger (the entire portion consisting of the straight portion and the bent portion), the advantages of both the arrangement in the straight portion or the bent portion can be exhibited, and noise during blowing And wind speed balance can be improved. Furthermore, by unifying all the fins into the same shape, it is not necessary to use the fins separately at the straight portion and the bent portion, and the production efficiency can be improved. Furthermore, about the uneven | corrugated shape of the fin edge part which has a recessed part, there is no waste at the time of material collection by making the shape of a recessed part and a convex part symmetrical, and it can suppress cost.

DESCRIPTION OF SYMBOLS 1 Blower 2 Heat exchanger 3 Water receptacle 4 Cabinet 5 Intake port 6 Outlet 7 Panel 8 Ceiling 9 Cabinet side wall surface 10 Fin 11 Heat transfer tube 12 Recessed part of front edge of fin cut out in a substantially rectangular shape 13 Direction of rotation of the blower 14 Air direction blown out from blower 15 Separation vortex generated at fin end 16 Air flow direction 17 Pitch of fin front edge end near heat transfer tube 18 Pitch of recess bottom end of fin

Claims (4)

In a separate type ceiling-embedded indoor unit provided with a ceiling-embedded cabinet that houses a blower and a heat exchanger, and a ceiling-exposed panel that horizontally arranges a suction port and a blow-out port,
The heat exchanger includes a plurality of heat transfer tubes, and a plurality of thin plate-shaped fins attached substantially perpendicular to the tube direction of the plurality of heat transfer tubes,
Further, the heat exchanger forms a straight portion in which the tube direction is a straight line and a bent portion in which the tube direction is a curve, and the air blower downstream of the blower so as to surround the outside of the blower Placed in
The thin plate-shaped fin has a recess cut out in a substantially rectangular shape at a front edge end portion located on the upstream side in the blowing direction,
The concave portion of the fin is provided in a portion separated from adjacent heat transfer tubes arranged in the vertical direction on the upstream side in the blowing direction, and the bottom surface of the concave portion is a heat transfer tube arranged in the vertical direction on the upstream side in the blowing direction. Located on the upstream side of the air blowing direction,
The fin having the recess is installed in a straight portion of the heat exchanger. In claim 1,
The air conditioner is characterized in that the fin having the concave portion is installed in a bent portion of the heat exchanger instead of being installed in the straight portion of the heat exchanger. In claim 1,
The air conditioner is characterized in that the fins having the recesses are installed in the entire part including the linear part and the bent part of the heat exchanger instead of being installed in the linear part of the heat exchanger. In claim 1, 2 or 3,
The air conditioner characterized in that the concave portion of the thin plate-like fin formed at the front edge end portion has a symmetrical shape with the convex portion formed at the front edge end portion.

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