JP2015055371A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize improvement of an energy-saving property and noise-reduction, while satisfying restraints in mounting an indoor heat exchanger.SOLUTION: A fin 11 is formed into an almost V-shape so that a segment L1 connecting an upper end 202a and a lower end 20 of a front edge 202 crosses a rear edge, and has an upper side fin 11A and a lower side fin 11B. A front edge 202 and a rear edge 203 of the upper side fin 11A have linear parts, and a front edge 301 and a rear edge 302 of the lower side fin 11B have curve parts curved from an upstream side toward a downstream side. When a larger angle among angles formed by a linear part and a horizontal line is designated as θ1, a smaller angle among angles formed by a reference line along a front edge of a connection portion 200 and the horizontal line is designated as θ3, and a smaller angle among angles formed by a tangential line at an upper end of the curve part and the horizontal line is designated as θ2, a relationship of θ1>θ3>θ2 is satisfied.

Description

  The present invention relates to an air conditioner using a cross fin tube type heat exchanger.

  In general, as one of the methods to improve the energy-saving performance of air conditioners, the required power of compressors, outdoor unit propeller fans, and indoor unit cross-flow fans, which are important elements of air conditioners, is reduced. It is possible. In order to reduce the required power of the compressor, it is effective to improve the heat transfer performance of the outdoor heat exchanger or the indoor heat exchanger and reduce the pressure difference between the high pressure part and the low pressure part. In order to reduce the required power of the propeller fan or cross-flow fan, it is effective to reduce the ventilation resistance of each of the outdoor heat exchanger and the indoor heat exchanger. Especially, from the viewpoint of improving the energy saving performance, the indoor heat exchange It is effective to improve the heat transfer performance and reduce the ventilation resistance.

  FIG. 7 shows the structure of a general cross fin tube type heat exchanger. As shown in the figure, the heat exchanger includes a large number of aluminum fins 11 and has a structure in which a copper heat transfer tube 12 bent into a U shape penetrates the fins 11. The fins 11 and the heat transfer tubes 12 are in close contact with each other by expanding the heat transfer tubes 12 inserted into the fins 11 either hydraulically or mechanically. Further, a joint part 13 is welded to the end of the heat transfer tube 12 to form a refrigerant flow path.

  In order to improve the heat transfer performance of heat exchangers, it is effective to increase the heat transfer area, and to reduce ventilation resistance, it is effective to reduce the flow velocity of the inflow air (front wind speed) by increasing the air inflow area (front area). . In the case of the heat exchanger shown in FIG. 7, the heat exchanger extends or expands in the axial direction of the heat transfer tube 12, or a step direction that is a direction orthogonal to the axial direction of the heat transfer tube 12 (a direction orthogonal to the air flow direction), That is, there is a method of extending and expanding the heat exchanger in the downward direction in FIG.

  However, the indoor unit of the air conditioner is required to be compact for convenience of installation, and it is not easy to extend and expand the indoor heat exchanger as described above. Under such restrictions, various ideas have been made for indoor heat exchangers from the viewpoint of performance improvement (for example, see Patent Document 1).

  FIG. 8 is a view showing a state where the indoor heat exchanger 70 of Patent Document 1 is mounted on the indoor unit 7, and shows the indoor unit in a cross section perpendicular to the axis of the heat transfer tube 12. The indoor heat exchanger 70 is divided into a front side heat exchanger 50 and a back side heat exchanger 60. In the front-side heat exchanger 50, a front edge 51 on the upstream side in the air flow direction and a rear edge 52 on the downstream side in the air flow direction connect the three straight portions 501 to 503 and these straight portions. The two curved portions 504 and 505 are curved so as to protrude from the downstream side to the upstream side.

  The housing 14 of the indoor unit 7 is provided with air suction ports 22 and 23 on the front and upper surfaces, and an air outlet 24 on the lower side. A cross-flow fan 9 is disposed in the housing 14, and the front-side heat exchanger 50 and the rear-side heat exchanger 60 are arranged in the middle of the air path from the air suction ports 22 and 23 to the cross-flow fan 9. A configured indoor heat exchanger 70 is installed. The front-side heat exchanger 50 and the back-side heat exchanger 60 are arranged in a substantially inverted V shape so as to surround the cross-flow fan 9.

In the indoor heat exchanger 70, condensed water is generated on the fin surface during the cooling operation or the dehumidifying operation. Therefore, when the inclination angle of the indoor heat exchanger 70 is small, the dew condensation water separates from the fin surface and is scattered into the room through the air outlet 24. For this reason, the front side heat exchanger 50 and the back side heat exchanger 60 are generally installed with predetermined inclination angles α and β.
Moreover, the front side heat exchanger 50 and the back side heat exchanger 60 have a configuration in which three rows of heat transfer tubes 12 are arranged in the air flow direction. Here, when the number of rows of the heat transfer tubes 12 is increased, the heat transfer area is increased and the heat transfer performance is improved, but on the other hand, the ventilation resistance is increased. Conversely, if the number of rows of the heat transfer tubes 12 is reduced, the ventilation resistance is reduced, but the heat transfer area is also reduced and the heat transfer performance is lowered. Therefore, although depending on the diameter of the heat transfer tube 12, the number of rows of the heat transfer tubes 12 is often set to 3 in consideration of the balance between the ventilation resistance and the heat transfer performance.

  In the indoor unit shown in FIG. 8, when the cross-flow fan 9 is activated, indoor air flows from the air suction ports 22 and 23, exchanges heat with the internal refrigerant in the indoor heat exchanger 70, and is blown out from the air outlet 24. .

Japanese Patent No. 5081881

By the way, in such an air conditioner, in order to realize further energy saving, it is conceivable to expand the heat transfer area and the front area.
For example, in order to enlarge the heat transfer area and the front surface area of the back-side heat exchanger 60, as shown in FIG. It is conceivable to form it. However, by doing so, the extended region portion 61 is blocked by the back nose 16 located far from the cross-flow fan 9 and disposed on the back surface of the cross-flow fan 9. For this reason, in the back side heat exchanger 60, the location where it is difficult for the air to flow occurs, which hinders the improvement of energy saving.

On the other hand, as shown in FIG. 10, it is also conceivable to form the front side heat exchanger 50 by extending it in the step direction. In the example shown in FIG. 10, the front-side heat exchanger 50 is formed in a substantially square shape when viewed from the side, and the upper fin 53 that is on the upper side of the substantially rectangular connection portion 55 is maintained at the above-described inclination angle. In this state, it is formed to extend in the step direction.
However, if the front-side heat exchanger 50 is extended in the step direction to the same height as the lower end of the front-side heat exchanger 50 shown in FIG. 9, the connection portion 55 protrudes greatly forward, and the front-side heat exchanger 50. The depth dimension of will greatly increase. In order to avoid this, it is conceivable to bend the front-side heat exchanger 50 toward the rear cross-flow fan 9 at a certain position in the height direction. In consideration of the operation of the cross-flow fan 9, it is desirable that the lower fin 54 on the lower side of the connection portion 55 has a fin depth direction, that is, an air flow direction, generally facing the central axis of the cross-flow fan 9, as shown in FIG. Such a shape is desirable.

  However, as shown in FIG. 11 (a), when the connecting portion 55 (a sharp bent portion) is present in the front heat exchanger 50, a contracted flow 56 in which the air flow is concentrated is generated, and the flow is partially accelerated. Therefore, as shown in FIG. 11B, the wind speed distribution 57 becomes non-uniform. For this reason, the new subject that a noise falls by the effect | action to the once-through fan 9 will arise by the fall of a local heat-transfer performance in the inside of the front side heat exchanger 50, an increase in ventilation resistance, and the effect | action to the once-through fan 9.

  As a method of solving such a contracted flow 56, a method of increasing a bent portion in the front side heat exchanger 50 can be considered. In FIG. 12, a straight portion 58 in which the upstream front edge 51 and the downstream rear edge 52 are both linear is added to the bent portion 55. As described above, by forming the straight portion 58 in the bent portion 55, the bent portions 58a and 58b are newly formed at the upper and lower ends of the straight portion 58. The angles of the respective bent portions 58a and 58b are as follows. Since the angle is surely gentler than the angle before the linear portion 58 is formed, the contracted flow 56 (see FIG. 11A) is relaxed as a result.

  FIG. 13A shows the air flow direction in the vicinity of the straight portion 58 and in the vicinity of the fin and in the vicinity of the fin trailing edge. As shown in FIG. 13B, the wind velocity distribution 57 in the height direction becomes gentle, and the increase in the flow velocity at the location where each contracted flow 56 is generated is compared with that shown in FIG. 11B. It can be seen that it is suppressed.

As described above, it is possible to alleviate the contracted flow 56 by forming the straight portion 58. However, in order to realize further energy saving while forming the straight portion 58, for example, heat exchange on the front side is performed. If the vessel 50 is formed to extend in the step direction, it is necessary to dispose the lower fin 54 on the lower side of the linear portion 58 at an inclination angle close to the horizontal. In such a case, the air flow direction in the lower fin 54 does not face the direction passing through the central axis of the cross-flow fan 9, so that a sufficient air flow rate in the lower fin 54 cannot be ensured.
On the other hand, when the straight portion 58 is formed short, both ends of the straight portion 58 are close to each other as compared with the case where the straight portion 58 is formed long. There are challenges that are difficult to achieve.

  The present invention has been made in order to solve the above-described problems. While satisfying the restrictions on the mounting of the indoor heat exchanger, the present invention saves energy by reducing the ventilation resistance, expanding the heat transfer area, and improving the wind speed distribution. It is an object to provide an air conditioner that achieves both improvement in performance and noise reduction.

  In order to solve the above problems, an air conditioner according to the present invention has a casing having an air inlet and an air outlet, a cross-flow fan provided in the casing, a fin, and a U-shape penetrating the fin. A cross fin tube type indoor heat exchanger that is formed of bent heat transfer tubes and is arranged in a substantially inverted V shape so as to surround the cross-flow fan, and the indoor heat exchanger includes a front-side heat exchange The fins constituting the front side heat exchanger are generally shaped so that the line segment connecting the upper end and the lower end of the front edge crosses the rear edge of the fin. The upper fin and the lower fin are formed in a letter shape with a connecting portion interposed therebetween, and the front and rear edges of the upper fin have at least one straight portion, and the lower fin Is the front and rear edges of the side fins upstream of the air flow direction? It has at least one curved portion that curves toward the downstream side, and of the angles formed by the linear portion and the horizontal line, the larger angle is θ1, and the reference line and the horizontal line along the front edge of the connecting portion are The smaller angle is θ3, and the smaller angle among the angles formed by the tangent and the horizontal line at the upper end of the bending portion is θ2, and these are θ1> θ3> θ2. It is characterized by satisfying.

  According to the present invention, while satisfying restrictions on mounting of an indoor heat exchanger, air conditioning that achieves both energy saving and noise reduction by reducing ventilation resistance, expanding heat transfer area, and improving wind speed distribution. A machine is obtained.

It is a figure which shows the structure of the refrigerating cycle of the air conditioner which concerns on 1st Embodiment of this invention. It is a schematic sectional drawing which shows the indoor unit of the air conditioner which concerns on 1st Embodiment of this invention. It is an expanded sectional view showing details of a front side heat exchanger. (A) is a figure which shows the flow of the air in the lower part of the front side heat exchanger in an indoor heat exchanger, (b) is a figure which shows wind speed distribution. It is an expanded sectional view showing details of a front side heat exchanger in an indoor heat exchanger of an air harmony machine concerning a 2nd embodiment of the present invention. (A) is a figure which shows the flow of the air in the lower part of the front side heat exchanger in an indoor heat exchanger, (b) is a figure which shows wind speed distribution. It is a figure which shows the structure of a general cross fin tube type heat exchanger. It is a schematic sectional drawing which shows the indoor unit of the conventional air conditioner. It is a schematic sectional drawing at the time of enlarging a back side heat exchanger. It is a schematic sectional drawing at the time of enlarging a front side heat exchanger. (A) is a figure which shows the flow of the air in the lower part of a front side heat exchanger at the time of enlarging a front side heat exchanger, (b) is a figure which shows a wind speed distribution. It is a schematic sectional drawing at the time of enlarging a front side heat exchanger. (A) is a figure which shows the flow of the air in the lower part of a front side heat exchanger at the time of enlarging a front side heat exchanger, (b) is a figure which shows a wind speed distribution.

  Hereinafter, an embodiment of an air conditioner according to the present invention will be described with reference to the drawings. Here, in the following description, when referring to “up and down” and “back and forth”, the directions shown in FIGS.

(First embodiment)
First, the configuration of the refrigeration cycle of the air conditioner according to the present embodiment will be described. As shown in FIG. 1, the air conditioner functions when the outdoor unit 1 and the indoor unit 7 are connected by a connection pipe 10. The outdoor unit 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, a throttle device 6, and a propeller fan 5. The indoor unit 7 includes an indoor heat exchanger 8 and a cross-flow fan 9. A refrigerant is sealed inside the refrigeration cycle, and in this embodiment, R32 is used as the refrigerant.

  Next, the operation of each component will be described by taking the case of cooling operation as an example. In the case of cooling operation, the high-pressure gaseous refrigerant compressed by the compressor 2 is condensed by radiating heat to the outside air by the outdoor heat exchanger 4, and becomes a high-pressure liquid refrigerant. The liquid refrigerant is depressurized by the action of the expansion device 6, becomes a low-temperature low-pressure gas-liquid two-phase state, and flows to the indoor unit 7 through the connection pipe 10. The refrigerant that has entered the indoor unit 7 is evaporated by absorbing the heat of the indoor air in the indoor heat exchanger 8. The refrigerant evaporated in the indoor unit 7 returns to the outdoor unit 1 through the connection pipe 10, passes through the four-way valve 3, and is compressed again by the compressor 2.

  In the heating operation, the refrigerant flow path is switched by the four-way valve 3, and the high-pressure gaseous refrigerant compressed by the compressor 2 flows to the indoor unit 7 through the four-way valve 3 and the connection pipe 10. The refrigerant that has entered the indoor unit 7 is condensed by dissipating heat to the indoor air in the indoor heat exchanger 8, and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows to the outdoor unit 1 through the connection pipe 10. The high-pressure liquid refrigerant entering the outdoor unit 1 is depressurized by the action of the expansion device 6, becomes a low-temperature low-pressure gas-liquid two-phase state, evaporates by flowing into the outdoor heat exchanger 4 and absorbing the heat of the outdoor air. It becomes a gaseous refrigerant. The refrigerant that has become gaseous in the outdoor heat exchanger 4 passes through the four-way valve 3 and is compressed again by the compressor 2.

  As shown in FIG. 2, the housing 14 of the indoor unit 7 is provided with air inlets 22 and 23 on the front and upper surfaces, and an air outlet 24 on the lower side. A cross-flow fan 9 is disposed inside the casing 14, and a cross fin tube type indoor heat exchanger 8 is disposed in the middle of the air path from the air suction ports 22 and 23 to the cross-flow fan 9. Yes.

  The indoor heat exchanger 8 includes a fin 11 and a U-shaped heat transfer tube 12 penetrating the fin 11, and is disposed in a substantially inverted V shape so as to surround the cross-flow fan 9. The indoor heat exchanger 8 includes a front side heat exchanger 20 and a back side heat exchanger 30. The front side heat exchanger 20 and the back side heat exchanger 30 are in contact with each other at the upper part of the housing 14.

As shown in FIG. 3, the fins 11 constituting the front-side heat exchanger 20 are formed in a substantially square shape. The fin 11 has an upper-side fin 11A and a lower-side fin 11B across the connection portion 200 (the connection portion 200 is a portion that is neither the upper-side fin 11A nor the lower-side fin 11B). Here, the fin 11 has a line segment L1 (shown by a one-dot chain line) connecting the upper end 201a of the front edge 201 of the upper fin 11A and the lower end 301a of the front edge 301 of the lower fin 11B. Is formed so as to cross a part (a part of the rear edge 202 of the upper fin 11A and a part of the rear edge 302 of the lower fin 11B).
The line segment L1 only needs to have a positional relationship that crosses at least a part of the rear edge of the fin 11, and has a positional relationship that crosses the rear edge 202 of the upper fin 11A and the rear edge 212 of the connecting portion 200. May be.
Such a front-side heat exchanger 20 is positioned so as to cover the front of the cross-flow fan 9 in the circumferential direction as shown in FIG.

As shown in FIG. 3, the upper fin 11 </ b> A has substantially the entire front edge 201 and rear edge 202 formed in a straight line, and has a straight line portion. The leading edge 201 and the trailing edge 202 are parallel.
In addition, in the front edge 201 and the rear edge 202, the linear part should just be formed in a part, and it may be formed including the curved part in the other part. Further, the front edge 201 and the rear edge 202 may be formed to include two straight portions in the vertical direction (two straight portions that are continuous in the vertical direction or two straight portions that are discontinuous in the vertical direction). .

The lower fin 11B is formed in a curved shape in which substantially the entire front edge 301 and rear edge 302 are curved from the upstream side to the downstream side in the air flow direction (from the front side to the rear side). It is supposed to have a part. In other words, the leading edge 301 and the trailing edge 302 are located on the downstream side in the air flow direction with respect to the line segment L2 connecting two points on the curve (the upper end and the lower end of the curved portion in FIG. 3). It has a curved shape.
In addition, in the front edge 301 and the rear edge 302, the curved part should just be formed in a part, and the other part may be formed including the linear part. Further, the front edge 301 and the rear edge 302 may be formed to include two curved portions in the vertical direction (two curved portions that are continuous in the vertical direction or two curved portions that are discontinuous in the vertical direction). .

  In the present embodiment, the front edge 301 of the lower fin 11B is formed by an arc whose radius is the broken arrow Y1 in FIG. Although the arrow indicating the radius is not shown, the trailing edge 302 is also formed by an arc.

  The connecting portion 200 has a front edge 211 and a rear edge 212 formed in a straight line, and has a straight portion. A corner 221 between the front edge 211 and the front edge 201 of the upper fin 11A and a corner 222 between the front edge 211 and the front edge 301 of the lower fin 11B are rounded. Similarly, a corner 223 between the rear edge 212 and the rear edge 202 of the upper fin 11A and a corner 224 between the rear edge 212 and the rear edge 302 of the lower fin 11B are also formed in a round shape.

  The length (height) of the front edge 211 is set to a size that does not exceed twice the interval W1 between the heat transfer tubes 12 in the longitudinal direction of the fin 11 (here, the longitudinal direction of the upper fin 11A). The interval W1 may be an average interval between the heat transfer tubes 12. By setting to such a height, it becomes easy to arrange the heat transfer tubes 12 in the connection portion 200. If the length (height) of the front edge 211 exceeds twice the interval W1 between the heat transfer tubes 12, the connecting portion 200 becomes larger in the vertical direction, and the upper fin 11A and the lower fin are correspondingly increased. Since it interferes with the installation space of 11B, it is unpreferable on mounting.

In such a fin 11, the front edge 201 of the upper fin 11 </ b> A, the front edge 211 of the connecting portion 200, and the front edge 301 of the lower fin 11 </ b> B have the following relationship. A dotted line 401 in FIG. 3 is a horizontal line indicating the horizontal direction when incorporated in the indoor unit 7.
The larger angle of the angle formed by the front edge 201 of the upper fin 11A and the dotted line 401 with respect to the dotted line 401 is θ1, and the front edge 211 (reference line along the front edge 211) of the connecting portion 200 and the dotted line The smaller one of the angles formed with 401 is θ3, and the smaller one of the angles formed between the tangent line 402 at the upper end of the front edge 301 of the lower fin 11B (tangent line 402 at the upper end of the curved portion) and the dotted line 401. When θ is θ2, these are
It is set so as to satisfy the relationship of θ1>θ3> θ2.
This relationship is the same for the rear edge side of the fin 11.

  As described above, the front-side heat exchanger 20 of the present embodiment has a positional relationship in which the line segment L1 crosses a part of the rear edge of the fin 11, and the front edge 211 of the connection portion 200 is in the longitudinal direction of the fin 11. The conventional indoor heat exchanger shown in FIG. 10 is set so as not to exceed twice the interval W1 between the heat transfer tubes 12 and to satisfy the relationship of θ1> θ3> θ2. Compared to 70, installation that protrudes toward the front side of the housing 14 is possible. Thereby, the length of the front edge (front edge 201, 211, 301) of the front side heat exchanger 20 will be expanded, and a heat transfer area and a front surface area can be expanded. In addition, the flow velocity of the incoming air (front wind speed) can be reduced by expanding the front area.

  Next, with reference to FIG. 4, the state of the air flow in the lower part of the front-side heat exchanger 20 during mounting will be described. As shown in FIG. 4, the connecting portion 200 is provided with a front edge 211 and a rear edge 212 formed by straight portions, and both ends of the front edge 211 and the rear edge 212 are bent. Acceleration of the flow due to the merging of the flow rate is alleviated, and the difference between the flow speeds at the high speed and low speed is reduced.

Further, since the lower fin 11B having a curved portion in which the front edge 301 and the rear edge 302 are curved on the downstream side in the air flow direction is provided on the lower side of the connecting portion 200, the air flow is at the lower end of the rear edge 212. Concentrating on is relaxed.
In addition, since the leading edge 301 and the trailing edge 302 are curved toward the downstream side in the air flow direction, the upstream side of the leading edge 301 in the air flow direction compared to the conventional indoor heat exchanger 70 shown in FIG. Then, the distance with the front side housing | casing 15 (refer FIG. 2) of the indoor unit 7 is securable. Similarly, a distance from the front side housing 15 and the cross-flow fan 9 of the indoor unit 7 can be secured on the downstream side of the trailing edge 302 in the air flow direction. Thereby, the flow resistance of the air flowing through the lower fins 11 </ b> B of the front side heat exchanger 20 at a position lower than the uppermost part 15 a of the front side case 15 can be reduced. Therefore, compared with the conventional indoor heat exchanger 70 shown in FIG. 10, the air flow rate which passes the lower part of the front side heat exchanger 20 can be increased.

  This means that, when the air flow rate is the same, the flow rate of air flowing through the portion other than the lower portion of the front heat exchanger 20 is reduced and the flow velocity is lowered, thereby further improving the unevenness of the wind speed distribution. Therefore, high energy saving and quietness can be obtained.

Here, as a method of improving the nonuniformity of the wind speed distribution, changing the number of rows of the heat transfer tubes 12 for each place can be mentioned. For example, even with a method of reducing the number of rows of the heat transfer tubes 12 on the lower side of the connection portion 200, that is, on the lower side fin 11B, than that on the upper side fin 11A, it is possible to improve the nonuniformity of the wind speed distribution. However, since the number of heat transfer tubes 12 that can be arranged is reduced as compared with the case where the same number of fins 11 are arranged in the longitudinal direction, it is difficult to secure a heat transfer area. Further, considering the configuration of the refrigerant flow path, a method of branching into a plurality of paths is used in order to improve the performance. However, when the number of rows of the heat transfer tubes 12 is partially changed, the refrigerant is changed for each path. The number of the heat transfer tubes 12 through which the refrigerant flows is different, or the refrigerant flows through the heat transfer tubes 12 at different positions with respect to the flow direction of air for each path, resulting in a problem that the amount of heat exchanged differs for each path. On the other hand, if the refrigerant flow path is configured so that the exchange heat quantity is equal for each pass, the configuration of the refrigerant flow path is restricted.
In contrast, in the present embodiment, as described above, the air flow rate passing through the lower portion of the front heat exchanger 20 is increased as compared with the conventional indoor heat exchanger 70 shown in FIG. Since it is possible to improve the non-uniformity, it is not necessary to adjust the ventilation resistance by reducing the rows of the heat transfer tubes 12 for each place. Therefore, the same number of rows of the heat transfer tubes 12 in the front heat exchanger 20 can be arranged in the longitudinal direction of the fins 11, more heat transfer tubes 12 can be arranged, and the configuration of the refrigerant flow path is also possible. Easy. Therefore, the indoor heat exchanger 8 with high heat transfer performance can be obtained, and high energy saving performance can be obtained.

In the present embodiment, the case where the front edge 301 and the rear edge 302 are formed by arcs is illustrated, but the present invention is not limited to this. For example, even if an ellipse or a part of a parabola is used, the same applies. The effect is obtained. Note that the circle in the arc may be a polygon.
In this embodiment, the corner 221 between the front edge 201 and the front edge 211, the corner 222 between the front edge 211 and the front edge 301, the corner 223 between the rear edge 202 and the rear edge 212, and the rear edge 212. The corners 224 between the rear edge 302 and the rear edge 302 are rounded. However, these are for the purpose of facilitating the production, such as suppressing the generation of burrs when the fin is produced, and are limited to this. However, even if it is not formed, the same effects as the above-described effects can be obtained.

In addition, in the lower-side fin 11B, a continuous straight line portion may be provided at the upper end of the curved front edge 301 and connected to the front edge 211 of the connection portion 200 via this straight line portion. Similarly, in the lower fin 11 </ b> B, a straight line continuous to the upper end of the rear edge 302 may be provided and connected to the rear edge 212 of the connection portion 200 via this straight line. Also in this case, the same effects as the above-described effects can be obtained due to the presence of the curved portion.
Further, in the lower fin 11 </ b> B, a linear portion that continues to the lower end of the curved front edge 301 may be provided, or a linear portion that continues to the lower end of the curved rear edge 302 may be provided. Also in this case, the same effects as the above-described effects can be obtained due to the presence of the curved portion.

  Since the heat transfer tubes 12 of the front side heat exchanger 20 are arranged in the same number of rows (three rows) in the air flow direction, the wind speed distribution becomes substantially uniform, and the local heat transfer in the front side heat exchanger 50 is achieved. It is difficult to cause a decrease in thermal performance or an increase in ventilation resistance. This also serves to suppress an increase in noise.

(Second Embodiment)
The air conditioner of 2nd Embodiment is demonstrated with reference to FIG.
The present embodiment is different from the first embodiment in that the front edge 231 and the rear edge 232 of the connection portion 200 have curved protrusions that protrude in a curved shape from the downstream side to the upstream side in the air flow direction. However, there is no change in other configurations.

  The front edge 231 is an arc that contacts the lower end of the front edge 201 of the upper fin 11A and the upper end of the front edge 301 of the lower fin 11B. The rear edge 232 is an arc that touches the upper ends of the rear edge 202 of the upper fin 11A and the rear edge 302 of the lower fin 11B.

  The height of the front edge 231 is set to a size that does not exceed twice the interval W1 between the heat transfer tubes 12 in the longitudinal direction of the fin 11 (here, the longitudinal direction of the upper fin 11A). The interval W1 may be an average interval between the heat transfer tubes 12.

  Also in the present embodiment, the fin 11 is a line segment L1 (illustrated by a one-dot chain line) connecting the upper end 201a of the front edge 201 of the upper fin 11A and the lower end 301a of the front edge 301 of the lower fin 11B. However, it is formed in a substantially U shape by being in a positional relationship across a part of the rear edge of the fin 11 (a part of the rear edge 202 of the upper fin 11A and the rear edge 302 of the lower fin 11B). ing.

In such a fin 11, the front edge 201 of the upper fin 11A, the front edge 231 of the connecting portion 200, and the front edge 301 of the lower fin 11B have the following relationship. Note that a dotted line 401 in FIG. 5 is a horizontal line indicating the horizontal direction when incorporated in the indoor unit 7.
The larger one of the angles formed by the front edge 201 of the upper fin 11A and the dotted line 401 with respect to the dotted line 401 is θ1, and the most from the cross-flow fan 9 (see FIG. 2) on the front edge 231 of the connecting portion 200. The smaller angle formed by the tangent line 406 (reference line) of the distant portion 231a and the dotted line 401 is θ3, and the tangent line 402 at the upper end of the front edge 301 of the lower fin 11B (tangent line 402 at the upper end of the curved portion). When the smaller angle among the angles formed by the dotted line 401 is θ2, these are:
It is set so as to satisfy the relationship of θ1>θ3> θ2.
This relationship is the same for the rear edge side of the fin 11.

  As described above, the front-side heat exchanger 20 of the present embodiment has a positional relationship in which the line segment L1 crosses a part of the rear edge of the fin 11, and the height of the connection portion 200 (height of the front edge 231). Is set to a size that does not exceed twice the interval W1 between the heat transfer tubes 12 in the longitudinal direction of the fin 11 and satisfies the relationship of θ1> θ3> θ2 as described above. As in one embodiment). Thereby, the installation which protrudes largely toward the front side of the housing | casing 14 is attained compared with the conventional indoor heat exchanger 70 shown in FIG. Thereby, the length of the front edge (front edge 201,231,301) of the front side heat exchanger 20 will be expanded, and a heat transfer area and a front surface area can be expanded. In addition, the flow velocity of the incoming air (front wind speed) can be reduced by expanding the front area.

  Next, with reference to FIG. 6, the state of the air flow in the lower part of the front-side heat exchanger 20 during mounting will be described. As shown in FIG. 6, the connecting portion 200 is provided with a front edge 231 and a rear edge 232 formed by curved protrusions, and both ends of the front edge 231 and the rear edge 232 have a curved shape. The acceleration of the flow due to the merging of the flows is mitigated, and the difference between the flow speeds at the high speed part and the low speed part becomes small.

Although a slight contraction is generated, the front edge 231 and the rear edge 232 of the connection portion 200 constitute one bent portion in the entire curve, and thus the contraction can be appropriately mitigated.
Further, since the distance from the cross-flow fan 9 to the forefront portion (the farthest portion 231a) of the front heat exchanger 20 is slightly larger than that of the first embodiment, the indoor heat exchanger is slightly increased. Although the depth dimension of 8 will increase, in this embodiment, the wind speed distribution can be further improved, and higher energy saving and quietness can be obtained.

In the present embodiment, the case where the front edge 231 and the rear edge 232 of the connection portion 200 are formed as arcs is illustrated, but the present invention is not limited to this. For example, an elliptical shape or a part of a parabola is used. However, the same effect can be obtained.
Further, the front edge 231 and the rear edge 232 may be formed including a straight portion. Even in this case, the same effects as the above-described effects can be obtained.
Further, it is sufficient that at least one curved protrusion is provided on the front edge 231 and the rear edge 232 of the connection portion 200, and two or more curved protrusions may be provided.

8 Indoor Heat Exchanger 9 Cross-flow Fan 11 Fin 11A Upper Side Fin 11B Lower Side Fin 12 Heat Transfer Tube 14 Housing 20 Front Side Heat Exchanger 22, 23 Air Suction Port 24 Air Blow Out Port 200 Connection Portion 201 Front Edge 201a Upper End 202 Rear Edge 211 Front edge 212 Rear edge 231 Front edge 231a The farthest part 232 Rear edge 301 Front edge 301a Lower end 302 Rear edge 401 Dotted line (horizontal line)
406 Tangent (reference line)
L1 line segment W1 Distance between heat transfer tubes

Claims (7)

A casing having an air inlet and an air outlet, a cross-flow fan provided in the casing, a fin and a heat transfer tube bent into a U shape penetrating the fin, and surrounding the cross-flow fan A cross fin tube type indoor heat exchanger arranged in a substantially inverted V shape,
The indoor heat exchanger has a front side heat exchanger and a back side heat exchanger,
The fins constituting the front side heat exchanger are:
The line segment connecting the upper end and the lower end of the front edge is formed in a substantially square shape so as to cross the rear edge of the fin, and has an upper fin and a lower fin across the connecting portion. ,
The front and rear edges of the upper fin have at least one straight line;
The front and rear edges of the lower fin have at least one curved portion that curves from the upstream side to the downstream side in the air flow direction,
Of the angles formed by the straight line portion and the horizontal line, the larger angle is θ1,
Of the angles formed by the reference line along the front edge of the connecting portion and the horizontal line, the smaller angle is θ3,
Among the angles formed by the tangent line and the horizontal line at the upper end of the curved portion, when the smaller angle is θ2, these are:
An air conditioner satisfying a relationship of θ1>θ3> θ2. The front and rear edges of the connecting portion have at least one straight line;
The air conditioner according to claim 1, wherein the reference line is a line along the straight line portion of the connection portion. The front edge and the rear edge of the connection portion have at least one curved protrusion that protrudes in a curved shape from the downstream side to the upstream side in the air flow direction,
2. The air conditioner according to claim 1, wherein the reference line is a tangent of a portion of the curved protrusion that is farthest from the cross-flow fan.   2. The air conditioner according to claim 1, wherein the connection portion is set to a size not exceeding twice the interval between the heat transfer tubes in the longitudinal direction of the fin.   The air conditioner according to claim 3, wherein a front edge and a rear edge of the curved protrusion are arc-shaped.   The air conditioner according to claim 1, wherein the heat transfer tubes of the front-side heat exchanger are arranged in the same number of rows in the air flow direction.   The air conditioner according to claim 6, wherein the heat transfer tubes are arranged in three rows in the air flow direction.

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