JP6678413B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner.

  As a method for improving the energy saving of the air conditioner, it is conceivable to improve the performance of a heat exchanger constituting the air conditioner. A heat exchanger of an air conditioner exchanges heat between a refrigerant flowing inside a heat transfer tube and air flowing outside the heat transfer tube. Methods for improving the performance of the heat exchanger include a method for improving the heat transfer performance, a method for reducing the flow loss of the refrigerant flowing inside the heat transfer tube, and a method for reducing the flow resistance of the air flowing outside the heat transfer tube. .

  In an air conditioner, a heat exchanger and a blower are arranged close to each other for miniaturization. Therefore, the wind speed distribution of the air flowing through the heat exchanger is not uniform. Therefore, in order to improve the performance of the heat exchanger, it is necessary to configure the heat exchanger and the refrigerant flow path in consideration of the wind speed distribution of the air.

Until now, in the indoor heat exchanger of the air conditioner, various measures have been taken to improve the performance by making the wind speed distribution uniform.
An example of such an indoor heat exchanger of an air conditioner is disclosed in Patent Document 1.

  In this Patent Document 1, "... the leeward leading edge and the leeward trailing edge of the fins 21 of the front-side heat exchanger 20 are formed by two straight portions having the same obtuse angle and between these two straight lines. The fins 21 of the substantially U-shaped front side heat exchanger 20 are sandwiched between a straight upwind front edge and a straight downwind rear edge. The distance between the leeward leading edge 23 and the leeward trailing edge 33 in one area closer to the once-through blower 5 of the two areas is set to the leeward leading edge 22 in the other area farther from the once-through blower 5. By making the distance shorter than the distance from the leeward rear edge 32, the larger finned heat exchanger 10 can be accommodated in a limited space, in particular, a space having a small depth, and a greater heat exchange ability can be exhibited. ... (see paragraph [0050], FIG. 2).

  In addition, Patent Document 1 discloses that “the fin 21 in the front-side heat exchanger 20 is inserted into a portion of a region sandwiched between the curved leeward front edge 24 and the curved leeward rear edge 34. The stepwise pitch of the heat transfer tubes 11 is equal to or less than the row on the leeward side of the gas flow compared to the row on the leeward side of the gas flow. Can be increased as much as possible to increase the ventilation resistance in this region, and thus the wind speed distribution of the finned heat exchanger 10 can be made more uniform, so that a greater heat exchange capacity can be exhibited. Yes (see paragraph [0059], FIG. 2).

JP 2008-215694 A

The indoor heat exchanger of the air conditioner described in Patent Literature 1 is configured such that the area of the fin in a region close to the once-through blower 5 (a short distance in the air flow path with the once-through fan) is set to the far side. By making the area smaller than the area of the fin, the size of the indoor unit is reduced while ensuring energy saving.
The indoor heat exchanger described in Patent Literature 1 has an energy saving effect by increasing the number of heat transfer tubes installed while suppressing an increase in ventilation resistance in a region of the front-side heat exchanger close to the cross-flow fan. We are improving.

  However, the indoor heat exchanger described in Patent Literature 1 is not necessarily sufficient as a configuration in consideration of the wind speed distribution of air flowing through the heat exchanger, and further improvement in energy saving is desired.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide an air conditioner with improved energy saving.

In order to solve the above-described problem, an air conditioner according to the present invention has a housing having an air inlet and an air outlet, and air and a refrigerant sucked into the housing from the air inlet. A heat exchanger that exchanges heat between the heat exchanger, the heat exchanger is disposed downstream of the air flow from the air suction port with respect to the heat exchanger, and the heat exchanged air in the heat exchanger is passed through the air outlet from the air outlet. A blower fan that discharges the heat to the outside of the housing, the heat exchanger includes a plurality of heat transfer tubes through which the refrigerant flows, and fins that are thermally connected to the heat transfer tubes. Comprises a first heat exchanger and a second heat exchanger, wherein the first heat exchanger is disposed closer to the blower fan than the second heat exchanger, The first heat exchanger and the second heat exchanger surround the blower fan. A is disposed in a substantially inverted V-shape, the number of cut and raised per unit area in the fins constituting the first heat exchanger, per unit area in the fin which forms the second heat exchanger So that the first heat exchanger is used on the most upstream side of the heat exchanger in the refrigerant flow during operation for heating the air sucked into the housing. It is characterized by comprising.

  According to the present invention, it is possible to provide an air conditioner with improved energy saving.

It is a block diagram of a general refrigeration cycle used for an air conditioner. It is a figure which shows the structure of the element of a general cross fin tube type heat exchanger. It is sectional drawing of the indoor unit of the air conditioner which concerns on 1st Embodiment. It is a figure showing a refrigerant channel composition in an indoor heat exchanger in an indoor unit of an air conditioner concerning a 1st embodiment. It is the figure which expanded the front heat exchanger and the back heat exchanger which comprise the indoor heat exchanger in the indoor unit of the air conditioner which concerns on 1st Embodiment. FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5. It is a figure which shows typically the temperature distribution in each position of the refrigerant | coolant flow direction at the time of the heating operation in the indoor unit of an air conditioner. It is the figure which expanded the front heat exchanger and the back heat exchanger which comprise the indoor heat exchanger in the indoor unit of the air conditioner which concerns on 2nd Embodiment. It is a figure which shows the refrigerant | coolant flow path structure in the indoor heat exchanger in the indoor unit of the air conditioner which concerns on 2nd Embodiment. It is the figure which expanded the front heat exchanger and the back heat exchanger which comprise the indoor heat exchanger in the indoor unit of the air conditioner which concerns on 3rd Embodiment. It is the figure which expanded the front heat exchanger and the back heat exchanger which comprise the indoor heat exchanger in the indoor unit of the air conditioner which concerns on 4th Embodiment.

An embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
In each of the drawings described below, common portions are denoted by the same reference numerals, and redundant description will be omitted as appropriate.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS.

First, a basic configuration of the air conditioner will be described.
FIG. 1 is a configuration diagram of a general refrigeration cycle used in an air conditioner 100 having operation modes of a cooling operation, a heating operation, and a reheat dehumidification operation.

  The air conditioner 100 includes an outdoor unit 1 and an indoor unit 2, and functions by connecting the outdoor unit 1 and the indoor unit 2 via connection pipes 3 and 4.

  The indoor unit 2 includes a first heat exchanger 21, a second heat exchanger 22, a second expansion device (an expansion device) 24, and a blower fan 25. The first heat exchanger 21 and the second heat exchanger 22 constitute an indoor heat exchanger (heat exchanger) 20. The second expansion device 24 is provided on a refrigerant flow path connecting the first heat exchanger 21 and the second heat exchanger 22.

  The outdoor unit 1 includes a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, a first expansion device 14, and a blower fan 15. In FIG. 1, for convenience of illustration, the refrigerant flow path of the four-way valve 12 shows a state during a heating operation. Usually, a propeller fan is used as the blower fan 15 of the outdoor unit 1, and a once-through fan is used as the blower fan 25 of the indoor unit 2.

  FIG. 2 is a diagram showing the structure of elements of a general cross-fin tube type heat exchanger of the same type as that used in the heat exchanger of the air conditioner 100.

  As shown in FIG. 2, this type of heat exchanger includes a plurality of heat transfer tubes 102 through which a refrigerant flows, and fins 101 thermally connected to the heat transfer tubes 102. Specifically, in this heat exchanger, a large number of aluminum plate-like fins 101 which are stacked and arranged at intervals are formed by a copper heat transfer tube 102 bent in a U-shape at the open end thereof. It has a structure that penetrates from the part side. The fin 101 and the heat transfer tube 102 are in close contact with each other by hydraulically or mechanically expanding the heat transfer tube 102 inserted into the fin 101. Further, a joint part 103 is welded to an open end of the heat transfer tube 102 to form a coolant flow path.

  Usually, the heat exchanger of the air conditioner 100 has a configuration in which a plurality of heat exchangers having the configuration shown in FIG. 2 are arranged in the air flow direction in order to improve efficiency. Further, the refrigerant flow path in the heat exchanger is configured with the number of passes corresponding to the flow rate of the refrigerant flowing in the pipe.

  Next, the operation of each element of the air conditioner 100 in each operation mode of the heating operation, the cooling operation, and the reheat dehumidification operation will be described with reference to FIG.

  In the case of the heating operation mode, the four-way valve 12 switches the refrigerant flow path to the state shown in FIG. The high-pressure gaseous refrigerant compressed by the compressor 11 flows through the four-way valve 12 and the connection pipe 3 to the indoor unit 2. The refrigerant that has entered the indoor unit 2 flows through the first heat exchanger 21 and the second heat exchanger 22 in order, and is condensed by radiating heat to indoor air to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows to the outdoor unit 1 through the connection pipe 4.

  The high-pressure liquid refrigerant that has entered the outdoor unit 1 is depressurized by the action of the first expansion device 14, enters a low-temperature, low-pressure gas-liquid two-phase state, flows to the outdoor heat exchanger 13, and absorbs the heat of the outdoor air. And evaporates into a gaseous refrigerant. The gaseous refrigerant in the outdoor heat exchanger 13 passes through the four-way valve 12 and is compressed again by the compressor 11. At this time, the second expansion device 24 is in a fully opened state.

  On the other hand, in the case of the cooling operation mode, although not shown in FIG. 1, the refrigerant flow path is switched by changing the valve body position of the four-way valve 12. The high-pressure gaseous refrigerant compressed by the compressor 11 is condensed by radiating heat to the outside air in the outdoor heat exchanger 13 to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is depressurized by the action of the first expansion device 14, enters a low-temperature low-pressure gas-liquid two-phase state, and flows through the connection pipe 4 to the indoor unit 2.

  The refrigerant that has entered the indoor unit 2 flows through the second heat exchanger 22 and the first heat exchanger 21 in order, and evaporates by absorbing the heat of the indoor air. The refrigerant evaporated in the indoor unit 2 returns to the outdoor unit 1 through the connection pipe 3, and is compressed again by the compressor 11 through the four-way valve 12. Also in the case of the cooling operation mode, the second expansion device 24 is in the fully opened state, as in the case of the heating operation mode.

Next, the reheat dehumidification operation mode will be described. In the reheat dehumidification operation mode, the flow direction of the refrigerant is the same as in the cooling operation mode.
That is, the high-pressure gaseous refrigerant compressed by the compressor 11 flows to the indoor unit 2 through the outdoor heat exchanger 13, the first expansion device 14, and the connection pipe 4. The refrigerant that has entered the indoor unit 2 passes through the second heat exchanger 22, passes through the second expansion device 24, the first heat exchanger 21, passes through the connecting pipe 3, returns to the outdoor unit 1, and returns to the four-way It flows again to the compressor 11 through the valve 12.

  In the reheat dehumidification operation mode, the air passing through the first heat exchanger 21 is cooled and dehumidified, and the air passing through the second heat exchanger 22 is heated, so that the change in the temperature of the indoor air is suppressed while the humidity is suppressed. Is controlled to lower.

  In order to heat the air passing through the second heat exchanger 22, the high-pressure gaseous refrigerant compressed by the compressor 11 is not condensed into a liquid refrigerant by the outdoor heat exchanger 13, It is necessary to flow to the indoor unit 2 via the connection pipe 4 in the two-phase state. For this reason, the first expansion device 14 is controlled to an open side or a fully opened state as compared with the cooling operation mode. The amount of heating in the second heat exchanger 22 is controlled by controlling the number of rotations (rotation speed) of the blower fan 15 per unit time in addition to controlling the opening degree of the first expansion device 14. It is adjusted by controlling the amount of heat radiated to the outside air.

  Although not shown, the blower fan 15 is also used for cooling the compressor 11 and electrical components for controlling the blower fan 15, and therefore, does not operate at low speed or intermittently in the reheat dehumidifying operation mode. Even if it does, it will not stop completely.

  Due to the above control, the refrigerant that has entered the indoor unit 2 in a high-temperature, high-pressure gas-liquid two-phase state passes through the second heat exchanger 22 and the indoor air passing through the second heat exchanger 22 by the operation of the blower fan 25. The liquid refrigerant is condensed by radiating heat to form a liquid refrigerant. Thereby, the air passing through the second heat exchanger 22 is heated, and the temperature rises.

  Subsequently, the liquid refrigerant flows to the second expansion device 24. In the reheat dehumidifying operation mode, the second expansion device 24 is controlled to be closed so as to have a flow path resistance. Therefore, the liquid refrigerant is depressurized by the action of the second expansion device 24, enters a low-temperature low-pressure gas-liquid two-phase state, and flows to the first heat exchanger 21. The low-temperature low-pressure gas-liquid two-phase refrigerant evaporates in the first heat exchanger 21 by absorbing heat from the air passing through the first heat exchanger 21 by the operation of the blower fan 25. At this time, the air passing through the first heat exchanger 21 is cooled and dehumidified. As described above, by heating the air in the second heat exchanger 22 and cooling and dehumidifying the air in the first heat exchanger 21, the reheat dehumidification operation mode suppresses the temperature change of the indoor air, It is possible to dehumidify.

FIG. 3 is a cross-sectional view of the indoor unit 2 of the air conditioner 100 according to the first embodiment.
As shown in FIG. 3, an air suction port 40 is provided in a housing 30 constituting the indoor unit 2. The air suction port 40 has a front air suction port 41 provided on the front surface of the housing 30 and an upper air suction port 42 provided above the housing 30. A rectangular air filter 51 is provided so as to cover them, and dust is prevented from entering the interior of the indoor unit 2. In addition, an air outlet 43 is provided at a lower portion of the housing 30, from which conditioned air such as cold air or hot air is blown. Further, a panel 31 is provided on the front surface of the housing 30, and forms a front air inlet 41 together with the housing 30.

  A blower fan 25 is provided inside the housing 30. In the middle of the air passage from the front air inlet 41 and the upper air inlet 42 to the blower fan 25, indoor heat exchange constituted by the front heat exchanger 200, the rear heat exchanger 300, and the auxiliary heat exchanger 400 is provided. A vessel 20 is provided. Further, the front heat exchanger 200 and the rear heat exchanger 300 are joined at the upper part, and are disposed in a substantially inverted V-shape so as to surround the blower fan 25.

  The indoor heat exchanger 20 exchanges heat between the air sucked into the housing 30 from the air suction port 40 and the refrigerant. The blower fan 25 is arranged on the downstream side of the indoor heat exchanger 20 in the air flow from the air suction port 40, and transfers the heat exchanged in the indoor heat exchanger 20 from the air outlet 43 to the housing 30. To the outside of the

  In addition, a tongue 32 that constitutes a part of the housing 30 is provided at a position facing the blower fan 25. When the blower fan 25 rotates, a circulating vortex is formed near the tongue 32 at a position facing the tongue 32. Accordingly, room air is sucked into the housing 30 through the front air suction port 41 and the upper air suction port 42, passes through the air filter 51, the indoor heat exchanger 20, and the blower fan 25. It is blown out to the exit 43. The blowing direction of the blown air can be controlled by a wind direction control plate 52 provided at the air outlet 43.

  As described above, since the circulating vortex formed at the portion facing the tongue portion 32 creates an air flow, the velocity distribution of the air flow passing through the blower fan 25 tends to be faster at the lower front surface near the tongue portion 32. is there.

  In the present embodiment, in the indoor heat exchanger 20, the front heat exchanger 200 and the rear heat exchanger 300 have a configuration in which the rows of the heat transfer tubes 102 are arranged in three rows in the air flow direction. The vessel 400 has a configuration in which the rows of the heat transfer tubes 102 are arranged in one row.

  FIG. 4 is a diagram illustrating a refrigerant flow path configuration in the indoor heat exchanger 20 in the indoor unit 2 of the air conditioner 100 according to the first embodiment.

  As shown in FIG. 4, in the heating operation mode, the refrigerant flowing from the outdoor unit 1 (see FIG. 1) flows into the indoor heat exchanger 20 from point A in FIG. The inflowing refrigerant is branched into four flow paths at the point B, flows through the lower part of the front heat exchanger 200 (the lower front heat exchanger 201), and then joins at the point C. From the point C, the flow passes through the second throttle device 24 to the point D while maintaining one flow path.

  Subsequently, the refrigerant is branched into two flow paths at the point D, and passes through the two rows of heat transfer tubes on the downstream side of the air flow downstream of the rear heat exchanger 300 and the upper part of the front heat exchanger 200 (the upper front heat exchanger 202). After flowing, they merge at point E. After merging at the point E, the refrigerant flows through the uppermost heat exchanger tubes of the upper front heat exchanger 202 and the rear heat exchanger 300 and then flows through the auxiliary heat exchanger 400 while maintaining one flow path. Then, it reaches the point F which is the outlet of the indoor heat exchanger 20.

  Here, the lower front heat exchanger 201 corresponds to the first heat exchanger 21 (see FIG. 1). Further, the upper front heat exchanger 202, the rear heat exchanger 300, and the auxiliary heat exchanger 400 correspond to the second heat exchanger 22 (see FIG. 1).

  On the other hand, in the cooling operation mode, the refrigerant flows in from the point F contrary to the heating operation mode, and flows through the indoor heat exchanger 20 in a direction indicated by a broken arrow in FIG.

  In the reheat dehumidification operation mode, the high-temperature and high-pressure refrigerant flowing from the outdoor unit 1 flows into the indoor heat exchanger 20 from a point F in FIG. 4 in a gas-liquid two-phase state. On the way from the point F to the points E and D, the auxiliary heat exchanger 400, the rear heat exchanger 300, and the upper front heat exchanger 202 release heat to air to condense and liquefy. The high-pressure liquid refrigerant that has exited point D is decompressed when passing through the second expansion device 24, enters a low-temperature low-pressure gas-liquid two-phase state, flows to point C, and is branched into four flow paths. When flowing through the lower front heat exchanger 201, the air is cooled and dehumidified, merges at the point B, and flows to the point A which is the outlet of the indoor heat exchanger 20.

  FIG. 5 is an enlarged view of the front heat exchanger 200 and the rear heat exchanger 300 constituting the indoor heat exchanger 20 in the indoor unit 2 of the air conditioner 100 according to the first embodiment.

  As shown in FIG. 5, two cut-and-raised portions 104 are formed between the heat transfer tubes 102 in the step direction (direction orthogonal to the air flow) of each heat transfer tube 102 on the fin 101 constituting the front heat exchanger 200. The configuration is provided. On the other hand, the fin 101 constituting the rear heat exchanger 300 has a configuration in which three cut-and-raised portions 104 are provided between the heat transfer tubes 102 in the step direction.

FIG. 6 is a sectional view taken along the line VI-VI in FIG.
As shown in FIGS. 5 and 6, the cut-and-raised portion 104 is deformed so that a portion between a pair of substantially parallel cutting lines formed on the fin 101 projects toward one surface of the fin 101. It is formed. Here, the longitudinal end of the cut-and-raised portion 104 is connected to the flat portion of the fin 101, and the end of the cut-and-raised portion 104 in the width direction (a direction orthogonal to the longitudinal direction) is cut off from the flat portion of the fin 101. It is in a raised state.

  A broken line in FIG. 5 indicates a portion of the front heat exchanger 200 that is located downstream of the second expansion device 24 in the refrigerant flow path configuration illustrated in FIG. The boundary between the front heat exchanger 202 and the portion located upstream of the second expansion device 24 when viewed from the refrigerant flow direction during the heating operation, that is, the boundary between the lower heat exchanger 201 and the front heat exchanger 202 is shown. In the front heat exchanger 200 of the present embodiment, the fins of the upper front heat exchanger 202 and the fins of the lower front heat exchanger 201 are formed as one integrated fin.

  Here, the spacing in the step direction of the heat transfer tubes 102 in the front heat exchanger 200 is wider than the spacing in the step direction of the heat transfer tubes 102 in the rear heat exchanger 300. Specifically, the arrangement interval in the step direction of the heat transfer tubes 102 in the front heat exchanger 200 is, for example, 21.5 mm, and the arrangement interval in the step direction of the heat transfer tubes 102 in the rear heat exchanger 300 is, for example, 20 mm. .

  Further, in the present embodiment, the heat exchanger tubes having the same outer diameter are used for both the front heat exchanger 200 and the rear heat exchanger 300, and the outer tube diameter before expansion is, for example, 6.35 mm.

  FIG. 7 is a diagram schematically illustrating a temperature distribution at each position in the refrigerant flow direction in the indoor unit 2 of the air conditioner 100 during the heating operation. Here, the operation and effect of the present embodiment will be described with reference to FIG.

  As in the present embodiment, when the number of cut-and-raised portions 104 in the fins 101 of the front heat exchanger 200 on the side close to the blower fan 25 is reduced (hereinafter also referred to as “the number of cut-and-raised portions”), the front heat exchanger 200 is reduced. Of the rear heat exchanger 300 is reduced. Here, being close to the blower fan 25 means that the distance on the air flow path with the blower fan 25 is short. Further, as described above, the air flow due to the operation of the blower fan 25 tends to be faster near the tongue 32 (see FIG. 1). Therefore, in the front heat exchanger 200, in particular, in the lower front heat exchanger 201 close to the blower fan 25, the wind speed at the inlet (the windward edge of the indoor heat exchanger 20) tends to increase.

If the location where the wind speed becomes faster is used as the heat exchanger on the upstream side in the refrigerant flow direction during the heating operation, the superheated gas flowing into the indoor heat exchanger 20 during the heating operation can be efficiently cooled. For this reason, as shown in FIG. 7, in the present embodiment, the refrigerant generates heat in comparison with a conventional heat exchanger that does not particularly use a location where the wind speed becomes high as a heat exchanger on the upstream side in the refrigerant flow direction during the heating operation. It changes to a gas-liquid two-phase state more upstream of the exchanger.
Here, in FIG. 7, A0 is the region of the superheated gas in the conventional case, B0 is the region of the gas-liquid two-phase in the conventional case, A1 is the region of the superheated gas in the present embodiment, and B1 is In the case of the present embodiment, a gas-liquid two-phase region, C, indicates a region of the supercooled liquid.
In the conventional case and the case of the present embodiment, since the boundary point between the gas-liquid two-phase region and the supercooled liquid region is almost the same, the supercooled liquid region C is shown in common for both. I have.
As described above, in the present embodiment, a wider gas-liquid two-phase region in the indoor heat exchanger 20 can be secured. As a result, the condensing temperature, that is, the condensing pressure can be lowered, the required power required for the compressor 11 to increase the pressure can be reduced, and the energy saving can be improved.

  Since the lower front heat exchanger 201, which is the refrigerant inlet side during the heating operation, is a region of the superheated gas, the flow velocity of the refrigerant flowing in the pipe increases, and the flow loss may increase accordingly. For this reason, as shown in FIG. 4, the lower front heat exchanger 201 has a larger number of flow paths than the other places, that is, the upper front heat exchanger 202 and the rear heat exchanger 300. Is good.

  Here, when the number of cut-and-raised pieces in the front heat exchanger 200 including the lower front heat exchanger 201 on the upstream side in the refrigerant flow direction at the time of heating is smaller than that of the rear heat exchanger 300, the ventilation resistance of the front heat exchanger 200 is reduced. May be significantly reduced than the ventilation resistance of the backside heat exchanger 300. For example, when the number of cut-and-raised portions between the stepwise heat transfer tubes 102 in the front heat exchanger 200 is reduced to one, the number of fins of the front heat exchanger 200 and the back heat exchanger 300 is the same, that is, the installation interval of the fins 101 is reduced. If they are the same, the air volume of the air passing through the back heat exchanger 300 may be too low.

  When the amount of air flowing to the rear heat exchanger 300 is excessively reduced as described above, the number of fins of the front heat exchanger 200 is increased to be larger than the number of fins of the rear heat exchanger 300, that is, the installation interval of the fins 101 is narrowed. Good to do. By adjusting the ventilation resistance in this way, the air volume ratio of the air passing through the front heat exchanger 200 and the rear heat exchanger 300 can be adjusted, and the entire indoor heat exchanger 20 can be used efficiently.

  As described above, in the present embodiment, the indoor heat exchanger 20 includes the first heat exchanger 21 and the second heat exchanger 22, and the first heat exchanger 21 includes the second heat exchanger 21. It is arranged closer to the blower fan 25 than the exchanger 22. The fins 101 constituting the front heat exchanger 200 are provided with two cut-and-raised portions 104 between the stepwise heat transfer tubes 102, and the fins 101 constituting the backside heat exchanger 300 are provided with Three cut-and-raised portions 104 are provided between the heat tubes 102. That is, when comparing the number of cut-and-raised portions 104 per unit area in the fin 101, the first heat exchanger 21 is smaller than the second heat exchanger 22. Further, the first heat exchanger 21 is used on the most upstream side in the indoor heat exchanger 20 of the refrigerant flow during the operation of heating the air sucked into the housing 30 (in the heating operation in the present embodiment). It is configured to be.

Therefore, it is possible to reduce the ventilation resistance of the first heat exchanger 21 disposed near the blower fan 25 and at a location where the wind speed is high, and to increase the amount of air passing through the region where the superheated gas flows during the heating operation. . As a result, the superheated gas can be efficiently cooled, the gas-liquid two-phase region can be further expanded, and the heat exchange efficiency is improved. In addition, since the condensation temperature, that is, the condensation pressure is reduced by expanding the gas-liquid two-phase region, the power of the compressor 11 can be reduced. Furthermore, the fan input can be reduced by reducing the ventilation resistance of the first heat exchanger 21.
As described above, by sufficiently considering the wind speed distribution of the air flowing through the indoor heat exchanger 20, the air conditioner 100 with further improved energy saving can be provided.

  In the present embodiment, the first heat exchanger 21 is disposed on the front lower side with respect to the blower fan 25, and the second heat exchanger 22 is disposed on the front upper side with respect to the blower fan 25 from the rear side. Are located in That is, the present invention provides an indoor heat exchanger that is arranged in a substantially inverted V-shape so as to surround the blower fan 25 and expands the heat transfer area in a limited space to improve the heat exchange efficiency. 20 can be suitably applied.

  Further, in the present embodiment, a second throttle device 24 is provided on a refrigerant flow path connecting the first heat exchanger 21 and the second heat exchanger 22. With this configuration, the first heat exchanger 21 can be used as a cooling unit that cools the air during the reheating and dehumidifying operation, and a high cooling effect can be obtained.

  Further, in the present embodiment, during the dehumidifying operation, the first heat exchanger 21 functions as an evaporator, and the second heat exchanger 22 functions as a condenser. It is possible to dehumidify.

  Further, in the present embodiment, the space between the heat transfer tubes 102 of the front heat exchanger 200 in the step direction is wider than the space between the heat transfer tubes 102 of the rear heat exchanger 300 in the step direction. That is, comparing the number of heat transfer tubes 102 installed per unit area in the fin 101 (heat transfer tube arrangement density), the first heat exchanger 21 is smaller than the second heat exchanger 22. Thereby, air can be made to flow in the area | region where the superheated gas flows in the indoor heat exchanger 20 at the time of heating operation, and a larger air volume, and the energy saving property improves more.

  Further, in the present embodiment, the number of branches of the refrigerant channel in the first heat exchanger 21 is larger than the number of branches of the refrigerant channel in the second heat exchanger 22. According to such a configuration, since the first heat exchanger 21 during the heating operation is in the region of the superheated gas, it is possible to prevent the flow velocity of the refrigerant from becoming too fast and increasing the flow loss.

  It should be noted that the average installation interval of the fins 101 constituting the first heat exchanger 21 is made narrower than the average installation interval of the fins constituting the second heat exchanger 22 so as to be larger than the number of fins. Is also good. In this configuration, when the amount of air passing through the second heat exchanger 22 is excessively reduced due to the reduction in the number of cut-and-raised first heat exchangers 21, the ventilation resistance of the first heat exchanger 21 decreases. The ventilation resistance can be adjusted so as not to be too small. Therefore, the air volume ratio of the air passing through the first heat exchanger 21 and the second heat exchanger 22 can be adjusted, and the entire indoor heat exchanger 20 can be used efficiently.

[Second embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
Since the basic configuration is the same as that of the first embodiment, the differences will be mainly described here.

  FIG. 8 is an enlarged view of the front heat exchanger 200 and the rear heat exchanger 300 constituting the indoor heat exchanger 20 in the indoor unit 2 of the air conditioner 100 according to the second embodiment.

  As shown in FIG. 8, in the present embodiment, similarly to the first embodiment, the fins 101 constituting the front heat exchanger 200 are provided with two cut-and-raised portions 104 between the stepwise heat transfer tubes 102. Configuration. The fin 101 constituting the backside heat exchanger 300 has a configuration in which three cut-and-raised portions 104 are provided between the heat transfer tubes 102 in the stepwise direction. Further, in the front heat exchanger 200, the fins of the upper front heat exchanger 202 and the fins of the lower front heat exchanger 201 are formed as integral fins.

  Here, the heat transfer tubes 102 in the lower front heat exchanger 201 have an outer diameter of, for example, 5.0 mm before expansion, and the heat transfer tubes 102 in the upper front heat exchanger 202 and the rear heat exchanger 300 are not expanded. Is, for example, 6.35 mm. As described above, in the present embodiment, the heat transfer tube 102 having a small outer diameter is used for the lower front heat exchanger 201.

  In addition, the spacing between the heat transfer tubes 102 in the front heat exchanger 200 in the step direction is smaller than the spacing between the heat transfer tubes 102 in the back heat exchanger 300 in the step direction. Specifically, the arrangement interval in the step direction of the heat transfer tubes 102 in the front heat exchanger 200 is, for example, 17 mm, and the arrangement interval in the step direction of the heat transfer tubes 102 in the rear heat exchanger 300 is, for example, 20 mm.

  As described above, when the heat transfer tube 102 having a smaller diameter than the upper front heat exchanger 202 and the rear heat exchanger 300 is used for the lower front heat exchanger 201, the ventilation resistance of the lower front heat exchanger 201 is reduced by other heat exchange. Heat exchangers, ie, the upper front heat exchanger 202, the rear heat exchanger 300, and the auxiliary heat exchanger 400. For this reason, the air volume of the air passing through the lower front heat exchanger 201 can be further increased.

  FIG. 9 is a diagram illustrating a refrigerant flow path configuration in the indoor heat exchanger 20 in the indoor unit 2 of the air conditioner 100 according to the second embodiment. In the second embodiment, the refrigerant flow path from the point B to the point C in FIG. 9 in the lower front heat exchanger 201 is composed of six branches, whereas in the first embodiment, the refrigerant flow path is the B Both are different in that the refrigerant flow path from the point to the point C is constituted by four branches. As described above, when the heat transfer tubes 102 having a smaller diameter than the upper front heat exchanger 202 and the rear heat exchanger 300 are used for the lower front heat exchanger 201, the number of flow paths suitable for the diameter of the heat transfer tubes 102 to be used. May be configured.

  As described above, in the second embodiment, the outer diameter of the heat transfer tube 102 forming the first heat exchanger 21 (the lower front heat exchanger 201) is changed to the heat transfer tube forming the second heat exchanger 22. 102 is smaller than the outer diameter. According to such a second embodiment, since the air volume of the air passing through the first heat exchanger 21 can be further increased, it is possible to obtain an effect equal to or more than the effect described in the first embodiment. it can. Furthermore, when the heat transfer tubes 102 having a small diameter are used, even if the arrangement density of the heat transfer tubes 102 is increased and the number of the heat transfer tubes 102 is increased, the ventilation resistance can be reduced, so that the heat transfer area can be increased and higher energy saving can be achieved. Sex can be obtained.

[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
Since the basic configuration is the same as that of the first embodiment, the differences will be mainly described here.

  FIG. 10: is the figure which expanded the front heat exchanger 200 and the back heat exchanger 300 which comprise the indoor heat exchanger 20 in the indoor unit 2 of the air conditioner 100 which concerns on 3rd Embodiment.

  As shown in FIG. 10, a fin 101 constituting a lower front heat exchanger 201 of a front heat exchanger 200 has a configuration in which two cut-and-raised portions 104 are provided between heat transfer tubes 102 in a stepwise direction. . On the other hand, the fin 101 constituting the upper front heat exchanger 202 and the rear heat exchanger 300 has a configuration in which three cut and raised portions 104 are provided. Further, in the present embodiment, as in the first embodiment, in the front heat exchanger 200, the fins of the upper front heat exchanger 202 and the fins of the lower front heat exchanger 201 are formed as integral fins.

The configuration of the refrigerant channel is the same as the configuration shown in FIG. 4 of the first embodiment.
Also, the broken line in FIG. 10 indicates the boundary between the lower front heat exchanger 201 and the upper front heat exchanger 202 as in FIG. That is, the dashed line in FIG. 10 indicates a portion of the front heat exchanger 200 that is located downstream of the second expansion device 24 in the refrigerant flow path configuration shown in FIG. 3 shows a boundary with a location located upstream of the second expansion device 24 when viewed from the refrigerant flow direction during the heating operation.

  Further, the space between the heat transfer tubes 102 in the lower front heat exchanger 201 in the step direction is wider than the space between the heat transfer tubes 102 in the upper front heat exchanger 202 and the rear heat exchanger 300 in the step direction. Specifically, the arrangement interval of the heat transfer tubes 102 in the lower front heat exchanger 201 is, for example, 22 mm, and the arrangement interval of the heat transfer tubes 102 in the upper front heat exchanger 202 and the rear heat exchanger 300 is 20 mm.

  The heat transfer tubes 102 used in the lower front heat exchanger 201, the upper front heat exchanger 202, and the rear heat exchanger 300 have an outer tube diameter of, for example, 6.35 mm before expansion.

As described above, in the third embodiment, the number of the cut-and-raised portions 104 per unit area in the fins 101 constituting the first heat exchanger 21 is different from the unit in the fins 101 constituting the second heat exchanger 22. Less than the number of cut-and-raised portions 104 per area. Further, the number of heat transfer tubes 102 per unit area (the heat transfer tube arrangement density) in the fins 101 constituting the first heat exchanger 21 (the lower front heat exchanger 201) constitutes the second heat exchanger 22. Less than the number of heat transfer tubes installed per unit area in the fins.
According to such a third embodiment, compared to the first embodiment, the air can be flowed at a larger air flow rate into the region where the superheated gas flows in the indoor heat exchanger 20 during the heating operation, and further savings can be achieved. An improvement in energy properties can be obtained.

  Further, as described in the first embodiment, also in the present embodiment, the number of fins of the front heat exchanger 200 is adjusted in order to adjust the air volume ratio of the air passing through the front heat exchanger 200 and the rear heat exchanger 300. Can be increased more than the number of fins of the rear heat exchanger 300. In this case, when the upper front heat exchanger 202 and the rear heat exchanger 300 are compared, the ventilation resistance of the rear heat exchanger 300 farther from the blower fan 25 can be relatively reduced. For this reason, the wind speed of the air passing through the upper front heat exchanger 202 and the rear heat exchanger 300 is made uniform.

  As shown in FIG. 7, during the heating operation, the refrigerant that has exited the second expansion device 24 is in a two-phase state, and its refrigerant flow path straddles the upper front heat exchanger 202 and the rear heat exchanger 300. And a plurality of flow paths. However, as described above, since the wind speed distribution can be made uniform between the upper front heat exchanger 202 and the rear heat exchanger 300, there is an advantage that the difference in the amount of heat released to the air in each refrigerant flow path is reduced.

  Further, as described in the second embodiment, also in this embodiment, the heat transfer tube 102 having a smaller diameter than the upper front heat exchanger 202 and the rear heat exchanger 300 may be used for the lower front heat exchanger 201. Good. By doing so, the amount of air flowing through the lower front heat exchanger 201 can be further increased, and the energy saving can be further improved.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
The basic configuration is the same as in the first embodiment and the third embodiment, and therefore, the differences will be mainly described here.

  FIG. 11 is an enlarged view of the front heat exchanger 200 and the rear heat exchanger 300 constituting the indoor heat exchanger 20 in the indoor unit 2 of the air conditioner 100 according to the fourth embodiment.

  As shown in FIG. 11, in this embodiment, the front heat exchanger 200 includes a lower front heat exchanger 201 composed of two blocks 201a and 201b and an upper front heat exchanger 202 composed of one block. It is composed of In the front heat exchanger 200 of the present embodiment, the fins of each block are configured as separate fins. However, the lower front heat exchanger 201 may be constituted by one block.

  Also in this embodiment, similarly to the third embodiment, the fin 101 constituting the lower front heat exchanger 201 is provided with two cut-and-raised portions 104 between the stepwise heat transfer tubes 102, The fin 101 constituting the front heat exchanger 202 and the rear heat exchanger 300 has a configuration in which three cut and raised portions 104 are provided.

The configuration of the refrigerant channel is the same as the configuration shown in FIG. 4 of the first embodiment.
Also, the broken line in FIG. 11 indicates the boundary between the lower front heat exchanger 201 and the upper front heat exchanger 202 as in FIGS. 5 and 8.

  As described in the first embodiment, also in the present embodiment, the average installation interval of the fins 101 constituting the first heat exchanger 21 (the lower front heat exchanger 201) is set to the second heat exchanger 22. Can be configured to be narrower than the average installation interval of the fins and to increase the number of fins more than the number of fins.

  Here, in the fourth embodiment, the lower front heat exchanger 201, the upper front heat exchanger 202, and the rear heat exchanger 300 are configured as separate blocks. Therefore, according to the fourth embodiment, it is possible to arbitrarily set the number of fins, that is, the fin installation intervals in each block, and there is an advantage that the wind speed distribution for each block can be arbitrarily set.

  As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments and modified examples, and includes various other modified examples. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. Further, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration.

  For example, in the above-described embodiment, the auxiliary heat exchanger 400 is provided in front of the front heat exchanger 200 (see FIG. 3), but the auxiliary heat exchanger 400 may be omitted, or the rear heat exchanger 400 may be provided. It may be arranged upstream of the vessel 300 in the air flow direction.

  Further, the boundary position between the lower front heat exchanger 201 and the upper front heat exchanger 202 in the front heat exchanger 200 is not limited to the position in each drawing such as FIGS. For example, the above-described boundary position can be determined by appropriately setting the size of the lower front heat exchanger 201 that functions as an evaporator during the reheat dehumidifying operation according to the dehumidifying capacity.

  Further, in the above-described embodiment, the air conditioner 100 having the reheat dehumidifying operation mode has been described as an example. Can also. In this case, for example, the configuration may be such that the second aperture device 24 shown in FIG. 4 is not provided. Even in such a case, the effects related to energy saving described in the above embodiment can be obtained in the same manner.

  Further, in the above-described embodiment, the case where the present invention is applied to the indoor unit 2 of the air conditioner 100 has been described. is there.

Reference Signs List 1 outdoor unit 2 indoor unit 13 outdoor heat exchanger 20 indoor heat exchanger (heat exchanger)
21 first heat exchanger 22 second heat exchanger 24 second throttling device (throttling device)
Reference Signs List 25 blower fan 30 housing 40 air inlet 43 air outlet 100 air conditioner 101 fin 102 heat transfer tube 200 front heat exchanger 201 lower front heat exchanger 202 upper front heat exchanger 300 rear heat exchanger

Claims (8)

A housing having an air inlet and an air outlet,
A heat exchanger that exchanges heat between the air and the refrigerant sucked into the housing from the air suction port,
A blower fan that is disposed downstream of the air flow from the air suction port with respect to the heat exchanger, and that discharges the heat exchanged air in the heat exchanger from the air outlet to the outside of the housing. Prepared,
The heat exchanger includes a plurality of heat transfer tubes through which the refrigerant flows, and fins that are thermally connected to the heat transfer tubes.
The heat exchanger includes a first heat exchanger and a second heat exchanger,
The first heat exchanger is disposed closer to the blower fan than the second heat exchanger,
The first heat exchanger and the second heat exchanger are disposed in a substantially inverted V shape so as to surround the blower fan,
The number of cuts and raised portions per unit area in the fins constituting the first heat exchanger is smaller than the number of cut and raised portions per unit area in the fins forming the second heat exchanger,
The first heat exchanger is configured to be used on the most upstream side of the heat exchanger in a refrigerant flow at the time of operation for heating air sucked into the housing. , Air conditioner.   The first heat exchanger is disposed at a lower front side with respect to the blower fan, and the second heat exchanger is disposed at a rear upper side with respect to the blower fan. 2. The air conditioner according to claim 1, wherein:   2. The air conditioner according to claim 1, wherein a throttle device is provided on a refrigerant flow path connecting the first heat exchanger and the second heat exchanger.   The air conditioner according to claim 3, wherein, during the dehumidifying operation, the first heat exchanger functions as an evaporator, and the second heat exchanger functions as a condenser.   The number of heat transfer tubes installed per unit area in the fins forming the first heat exchanger is smaller than the number of heat transfer tubes installed per unit area in the fins forming the second heat exchanger. The air conditioner according to any one of claims 1 to 4, wherein   The average installation interval of the fins constituting the first heat exchanger is narrower than the average installation interval of the fins constituting the second heat exchanger. 2. The air conditioner according to claim 1.   The outer diameter of a heat transfer tube forming the first heat exchanger is smaller than the outer diameter of a heat transfer tube forming the second heat exchanger. 2. The air conditioner according to claim 1.   The air conditioner according to claim 7, wherein the number of branches of the refrigerant channel in the first heat exchanger is larger than the number of branches of the refrigerant channel in the second heat exchanger.

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