JP6974720B2 - Heat exchanger and refrigeration equipment - Google Patents

Description

The present disclosure relates to a heat exchanger and a refrigerating apparatus equipped with the heat exchanger.

Conventionally, there is known a heat exchanger in which a plurality of heat exchange units in which a plurality of flat tubes through which a refrigerant flows are arranged are arranged in a plurality of rows in the air flow direction. For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2016-388192) discloses a heat exchanger having two rows of heat exchange units.

In Patent Document 1 (Japanese Unexamined Patent Publication No. 2016-388192), a heat exchanger is configured so that the refrigerant flows in opposite directions to the flat tube of the heat exchange section on the windward side and the flat tube of the heat exchange section on the leeward side. Has been done.

In Patent Document 1 (Japanese Unexamined Patent Publication No. 2016-388192), heat exchange units having the same configuration are arranged on the leeward side and the leeward side, so that efficiency is improved when the heat exchanger is used as a condenser. May not be fully achieved.

An object of the present disclosure is to provide a heat exchanger having a plurality of rows of heat exchange portions in which a plurality of flat tubes through which a refrigerant flows are arranged side by side, and which is excellent in efficiency.

The heat exchanger has a plurality of rows of heat exchange units. In the heat exchanger, a plurality of rows of heat exchange units are arranged so as to overlap in the air flow direction. In each heat exchange section, a plurality of flat multi-hole pipes extending from the first end side to the second end side and through which the refrigerant flows are arranged side by side in the first direction. The number of gas-side flat multi-hole pipes provided at one end of the gas refrigerant inlet / outlet included in the heat exchange section in the front row on the wind side is the number of gas-side flat multi-hole tubes included in the heat exchange section in the last row on the leeward side. Less than the number of tubes.

In this heat exchanger, for example, when the gas refrigerant flows into the gas refrigerant inlet / outlet of the gas side flat multi-hole tube (when the heat exchanger is used as a condenser), it is the last compared to the heat exchange section in the front row. The rate at which the high temperature gas refrigerant is cooled is high in the heat exchange section of the row. The high-temperature gas refrigerant can exchange heat relatively efficiently with the air having a high temperature on the leeward side (heated by the refrigerant on the leeward side). Therefore, heat exchange can be efficiently performed between the refrigerant and the air as compared with the case where such a configuration is not performed.

Preferably, in the heat exchanger, at least two rows of heat exchange sections include a gas-side flat multi-hole tube.

Here, by arranging the gas-side flat multi-hole pipes in the heat exchange portions in a plurality of rows, it is possible to realize a path taking with a high degree of freedom, and it is easy to realize a highly efficient heat exchanger.

Preferably, in the heat exchanger, the flat multi-hole tube further includes a liquid-side flat multi-hole tube provided at one end with a liquid refrigerant inlet / outlet, unlike the gas-side flat multi-hole tube.

More preferably, in the heat exchanger, the total number of gas-side flat multi-hole tubes is larger than the total number of liquid-side flat multi-hole tubes.

Here, by having more gas-side flat multi-hole pipes than liquid-side flat multi-hole pipes, performance deteriorates even under operating conditions where the degree of overheating is large when the heat exchanger is used as an evaporator. Can be suppressed.

Preferably, in the heat exchanger, the gas-side flat multi-hole tube is provided with a gas refrigerant inlet / outlet on the first end side.

Here, each of the plurality of rows of flat multi-hole pipes on the gas side is provided with a gas refrigerant inlet / outlet on the first end side. Therefore, the region of the gas-side flat multi-hole tube (overheated region) through which the high-temperature gas refrigerant flows and the region of the gas-side flat multi-hole pipe through which the lower temperature refrigerant flows are adjacent to each other, resulting in heat loss. Occurrence is likely to be suppressed.

Preferably, the heat exchanger is further provided with a confluence portion for merging the refrigerants flowing out from the plurality of gas-side flat multi-hole pipes and guiding them to the liquid-side flat multi-hole pipe.

Preferably, the heat exchanger further comprises a header tube that guides the refrigerant flowing out of the gas-side flat multi-hole tube to a plurality of liquid-side flat multi-hole tubes. Inside the header pipe, a partition plate for separating the refrigerant flowing out from the gas-side flat multi-hole pipe for each heat exchange unit is arranged.

Here, the refrigerant for each heat exchange unit, in other words, the refrigerants in different states can be guided to different liquid-side flat multi-hole pipes.

Preferably, in the heat exchanger, the refrigerant flows in the same direction through all the flat multi-hole tubes.

With such a configuration, regions in which the temperatures of the flowing refrigerants differ greatly can be arranged apart from each other, and the occurrence of heat loss is likely to be suppressed.

Preferably, the heat exchanger has three rows of heat exchangers.

Also, preferably, the heat exchanger has at least three rows of heat exchangers. Only the heat exchange part in the front row includes the liquid side flat multi-hole tube.

Here, when the condenser is used, the heating region is concentrated on the back row side, so that the performance can be improved.

Further, preferably, in the heat exchanger, the gas-side flat multi-hole tube includes a first gas-side flat multi-hole tube provided with a gas refrigerant inlet / outlet on the first end side. Preferably, the heat exchange portion is not arranged on the leeward side of the first gas side flat multi-hole tube in the air flow direction, or the first gas side flat multi-hole tube is on the leeward side in the air flow direction. Only the gas-side flat multi-hole pipe provided with the gas refrigerant inlet / outlet on the first end side is arranged at the same position as the first gas-side flat multi-hole pipe in the direction.

Here, for example, when a condenser is used, it is possible to prevent the once cooled refrigerant from being heated by the air warmed on the wind side, and it is possible to suppress performance deterioration.

Preferably, in the heat exchanger, a gas region through which the gas refrigerant flows is formed in the gas side flat multi-hole pipe in the vicinity of the gas refrigerant inlet / outlet. Preferably, the two-phase / liquid region through which the two-phase refrigerant or the liquid-phase refrigerant flows through the flat multi-hole tube is not arranged on the leeward side in the air flow direction of the gas region.

With such a configuration, the occurrence of heat loss is likely to be suppressed.

The refrigerating apparatus of the present disclosure is equipped with any of the above heat exchangers.

It is a schematic block diagram of the air conditioner which concerns on one Embodiment of a refrigerating apparatus. It is a perspective view of the indoor unit of the air conditioner of FIG. FIG. 3 is a schematic cross-sectional view taken along the line III-III in FIG. 2 of the indoor unit mounted on the ceiling. It is a bottom view schematically showing the schematic structure of the indoor unit of FIG. FIG. 4 depicts an indoor unit with the decorative panel removed. It is a schematic diagram schematically showing the indoor heat exchanger according to the first embodiment of the heat exchanger of the present disclosure as seen from the stacking direction of the flat multi-hole tube. It is a perspective view of the room heat exchanger of FIG. It is a perspective view which showed a part of the heat exchange part of the room heat exchanger of FIG. It is a schematic cross-sectional view of VIII-VIII arrow view of FIG. It is a schematic diagram which showed schematic structure of the room heat exchanger of FIG. FIG. 5 is a schematic diagram schematically showing the front row configuration of the indoor heat exchanger of FIG. It is a schematic diagram which showed schematic the back row structure of the room heat exchanger of FIG. It is a schematic diagram schematically showing the path of the refrigerant formed in the indoor heat exchanger of FIG. It is a schematic diagram which schematically showed the flow of the refrigerant at the time of a cooling operation in the front row heat exchange part of the room heat exchanger of FIG. It is a schematic diagram which schematically showed the flow of the refrigerant at the time of a cooling operation in the back row heat exchange part of the room heat exchanger of FIG. It is a schematic diagram schematically showing the flow of the refrigerant at the time of a heating operation in the front row heat exchange part of the indoor heat exchanger of FIG. It is a schematic diagram schematically showing the flow of the refrigerant at the time of a heating operation in the back row heat exchange part of the indoor heat exchanger of FIG. It is a schematic diagram schematically showing the path of the refrigerant formed in the indoor heat exchanger according to the modification 1A. It is a schematic diagram which schematically showed the flow of the refrigerant at the time of a heating operation in the front row heat exchange part and the back row heat exchange part of the room heat exchanger of FIG. It is a schematic diagram schematically showing the flow of the refrigerant at the time of a heating operation in the front row heat exchange part and the back row heat exchange part of the room heat exchanger which concerns on modification 1B. It is a schematic diagram schematically showing the indoor heat exchanger according to the second embodiment of the heat exchanger of the present disclosure seen from the stacking direction of the flat tube. It is a schematic diagram which showed schematic structure of the room heat exchanger of FIG. It is a schematic diagram schematically showing the path of the refrigerant formed in the indoor heat exchanger of FIG. 20. It is a schematic diagram schematically showing the front row configuration of the indoor heat exchanger of FIG. 20. It is a schematic diagram which showed schematic the middle row structure of the room heat exchanger of FIG. It is a schematic diagram which showed schematic the back row structure of the room heat exchanger of FIG. It is a schematic diagram schematically showing the flow of the refrigerant at the time of a heating operation in the front row heat exchange part of the indoor heat exchanger of FIG. It is a schematic diagram schematically showing the flow of the refrigerant at the time of a heating operation in the middle row heat exchange part of the room heat exchanger of FIG. It is a schematic diagram schematically showing the flow of the refrigerant at the time of a heating operation in the back row heat exchange part of the indoor heat exchanger of FIG. It is a schematic diagram which showed schematicly the path of the refrigerant formed in the room heat exchanger of the modification 2B. It is a schematic diagram schematically showing the flow of the refrigerant at the time of a heating operation in the front row heat exchange part, the middle row heat exchange part, and the back row heat exchange part of the room heat exchanger of FIG. It is a schematic diagram which schematically showed the flow of the refrigerant at the time of a heating operation in the front row heat exchange part, the middle row heat exchange part, and the back row heat exchange part of the room heat exchanger of the modification 2C. It is a schematic diagram schematically showing an example of the shape of the indoor heat exchanger to which this disclosure can be applied. It is a schematic diagram schematically showing an example of the shape of the indoor heat exchanger to which this disclosure can be applied. It is a schematic diagram schematically showing an example of the shape of the outdoor heat exchanger to which this disclosure can be applied.

Hereinafter, an embodiment of the heat exchanger of the present disclosure and an embodiment of the refrigerating apparatus of the present disclosure will be described with reference to the drawings. The same or similar members are designated by the same reference numerals across a plurality of drawings.

<First Embodiment>
The indoor heat exchanger 25 according to the first embodiment of the heat exchanger of the present disclosure and the air conditioner 100 according to the embodiment of the refrigerating apparatus of the present disclosure equipped with the indoor heat exchanger 25 will be described.

In the following embodiments, expressions such as up, down, left, right, front, and back may be used to explain directions and positional relationships, but the directions indicated by these expressions are arrows in the drawings. Follow the direction indicated by.

(1) Air Conditioning Device An outline of the air conditioning device 100 equipped with the indoor heat exchanger 25 will be described. FIG. 1 is a schematic configuration diagram of an air conditioner 100.

The air harmonizing device 100 is a device that performs cooling operation or heating operation to harmonize the air in the target space. Specifically, the air conditioner 100 has a refrigerant circuit RC and performs a vapor compression refrigeration cycle.

The air conditioner 100 mainly includes an outdoor unit 10 as a heat source unit and an indoor unit 20 as a utilization unit. In the air conditioner 100, the outdoor unit 10 and the indoor unit 20 are connected by a gas refrigerant connecting pipe GP and a liquid refrigerant connecting pipe LP to form a refrigerant circuit RC. As the refrigerant enclosed in the refrigerant circuit RC, for example, an HFC refrigerant such as R32 or R410A is enclosed. However, the type of the refrigerant is not limited to R32 and R410A, and may be HFO1234yf, HFO1234ze (E), a mixed refrigerant thereof, or the like.

The outdoor unit 10 and the indoor unit 20 will be further described.

(1-1) Outdoor unit The outdoor unit 10 is a unit installed outdoors.

The outdoor unit 10 mainly includes a compressor 11, a flow direction switching mechanism 12, an outdoor heat exchanger 13, an expansion mechanism 14, and an outdoor fan 15 (see FIG. 1).

Further, the outdoor unit 10 has a suction pipe 16a, a discharge pipe 16b, a first gas refrigerant pipe 16c, a liquid refrigerant pipe 16d, and a second gas refrigerant pipe 16e (see FIG. 1). The suction pipe 16a connects the flow direction switching mechanism 12 and the suction side of the compressor 11. The discharge pipe 16b connects the discharge side of the compressor 11 to the flow direction switching mechanism 12. The first gas refrigerant pipe 16c connects the flow direction switching mechanism 12 and the gas side end of the outdoor heat exchanger 13. The liquid refrigerant pipe 16d connects the liquid side end of the outdoor heat exchanger 13 to the liquid refrigerant connecting pipe LP. The expansion mechanism 14 is provided in the liquid refrigerant pipe 16d. The second gas refrigerant pipe 16e connects the flow direction switching mechanism 12 and the gas refrigerant connecting pipe GP.

The compressor 11 is a device that sucks in a low-pressure gas refrigerant, compresses it, and discharges it. The compressor 11 is an inverter-controlled compressor whose rotation speed of the motor can be adjusted (capacity can be adjusted). The rotation speed of the compressor 11 is adjusted by a control unit (not shown) according to the operating conditions. The compressor 11 may be a compressor in which the rotation speed of the motor is constant.

The flow direction switching mechanism 12 is a mechanism for switching the flow direction of the refrigerant in the refrigerant circuit RC according to the operation mode (cooling operation mode / heating operation mode). In the present embodiment, the flow direction switching mechanism 12 is a four-way switching valve.

In the cooling operation mode, the flow direction switching mechanism 12 switches the flow direction of the refrigerant in the refrigerant circuit RC so that the refrigerant discharged by the compressor 11 is sent to the outdoor heat exchanger 13. Specifically, in the cooling operation mode, the flow direction switching mechanism 12 communicates the suction pipe 16a with the second gas refrigerant pipe 16e and the discharge pipe 16b with the first gas refrigerant pipe 16c (see the solid line in FIG. 1). ). In the heating operation mode, the flow direction switching mechanism 12 switches the flow direction of the refrigerant in the refrigerant circuit RC so that the refrigerant discharged by the compressor 11 is sent to the indoor heat exchanger 25. Specifically, in the heating operation mode, the flow direction switching mechanism 12 communicates the suction pipe 16a with the first gas refrigerant pipe 16c and the discharge pipe 16b with the second gas refrigerant pipe 16e (see the broken line in FIG. 1). ).

The flow direction switching mechanism 12 is not limited to the four-way switching valve, and may be configured so as to be able to switch the flow direction of the refrigerant as described above by combining a plurality of solenoid valves and a refrigerant pipe.

The outdoor heat exchanger 13 is a heat exchanger that functions as a refrigerant condenser during cooling operation and as a refrigerant evaporator during heating operation. The outdoor heat exchanger 13 has a plurality of heat transfer tubes and a plurality of heat transfer fins (not shown).

The expansion mechanism 14 is a mechanism for reducing the pressure of the inflowing high-pressure refrigerant. In the present embodiment, the expansion mechanism 14 is an expansion valve whose opening degree can be adjusted. The opening degree of the expansion mechanism 14 is appropriately adjusted according to the operating conditions. The expansion mechanism 14 is not limited to the expansion valve, and may be a capillary tube or the like.

The outdoor fan 15 is a blower that flows into the outdoor unit 10 from the outside, passes through the outdoor heat exchanger 13, and generates an air flow that flows out to the outside of the outdoor unit 10. During operation, the outdoor fan 15 is driven by a control unit (not shown), and the rotation speed is appropriately adjusted.

(1-2) Indoor unit The indoor unit 20 is installed in a room (space subject to air conditioning). The indoor unit 20 mainly has an indoor heat exchanger 25 and an indoor fan 28 (see FIG. 1).

The indoor heat exchanger 25 according to the embodiment of the heat exchanger of the present disclosure functions as a refrigerant evaporator during the cooling operation and as a refrigerant condenser during the heating operation. A gas refrigerant pipe 21 is connected to the gas-side refrigerant inlet / outlet (gas-side inlet / outlet GH) of the indoor heat exchanger 25. The gas refrigerant pipe 21 is a pipe that connects the gas refrigerant connecting pipe GP and the indoor heat exchanger 25. The gas refrigerant pipe 21 is branched into a first gas refrigerant pipe 21a and a second gas refrigerant pipe 21b on the indoor heat exchanger 25 side (see FIG. 6 and the like, the branch portion is not shown). A liquid refrigerant pipe 22 is connected to a liquid-side refrigerant inlet / outlet (liquid-side inlet / outlet LH) of the indoor heat exchanger 25. The liquid refrigerant pipe 22 is a pipe connecting the liquid refrigerant connecting pipe LP and the indoor heat exchanger 25. The liquid refrigerant pipe 22 is branched into a first liquid refrigerant pipe 22a and a second liquid refrigerant pipe 22b on the indoor heat exchanger 25 side (see FIG. 6 and the like, the branch portion is not shown). Details of the indoor heat exchanger 25 will be described later.

The indoor fan 28 is a blower that generates an air flow (indoor air flow AF, see FIG. 5, etc.) that flows into the indoor unit 20 from the outside, passes through the indoor heat exchanger 25, and flows out to the outside of the indoor unit 20. .. During operation, the indoor fan 28 is driven by a control unit (not shown), and the rotation speed is appropriately adjusted.

(1-3) Gas refrigerant connecting pipe, liquid refrigerant connecting pipe The gas refrigerant connecting pipe GP and the liquid refrigerant connecting pipe LP are pipes laid at the installation site of the air conditioner 100. The pipe diameter and pipe length of the gas refrigerant connecting pipe GP and the liquid refrigerant connecting pipe LP are individually selected according to the design specifications and the installation environment.

The gas refrigerant connecting pipe GP is a pipe connecting the second gas refrigerant pipe 16e of the outdoor unit 10 and the gas refrigerant pipe 21 of the indoor unit 20, and is a pipe through which the gas refrigerant mainly flows. The liquid refrigerant connecting pipe LP is a pipe connecting the liquid refrigerant pipe 16d of the outdoor unit 10 and the liquid refrigerant pipe 22 of the indoor unit 20, and is a pipe through which the liquid refrigerant mainly flows.

(2) Flow of refrigerant in the air conditioner In the air conditioner 100, the refrigerant circulates in the refrigerant circuit RC during the cooling operation and the heating operation, respectively, as shown below.

(2-1) During cooling operation During cooling operation, the flow direction switching mechanism 12 is in the state shown by the solid line in FIG. 1, the discharge side of the compressor 11 communicates with the gas side of the outdoor heat exchanger 13, and the compressor 11 The suction side of the room communicates with the gas side of the indoor heat exchanger 25.

When the compressor 11 is driven in such a state, the low-pressure gas refrigerant is compressed by the compressor 11 to become a high-pressure gas refrigerant. The high-pressure gas refrigerant is sent to the outdoor heat exchanger 13 via the discharge pipe 16b, the flow direction switching mechanism 12, and the first gas refrigerant pipe 16c. Then, the high-pressure gas refrigerant is condensed into a high-pressure liquid refrigerant (liquid refrigerant in an overcooled state) by exchanging heat with the outdoor air in the outdoor heat exchanger 13. The high-pressure liquid refrigerant flowing out of the outdoor heat exchanger 13 is sent to the expansion mechanism 14. The low-pressure refrigerant decompressed by the expansion mechanism 14 flows through the liquid refrigerant pipe 16d, the liquid refrigerant connecting pipe LP, and the liquid refrigerant pipe 22, and flows into the indoor heat exchanger 25 from the liquid side inlet / outlet LH. The refrigerant flowing into the indoor heat exchanger 25 evaporates by exchanging heat with the indoor air to become a low-pressure gas refrigerant (overheated gas refrigerant) from the indoor heat exchanger 25 via the gas side inlet / outlet GH. leak. The refrigerant flowing out of the indoor heat exchanger 25 flows through the gas refrigerant pipe 21, the gas refrigerant connecting pipe GP, the second gas refrigerant pipe 16e and the suction pipe 16a, and is sucked into the compressor 11 again.

(2-2) During heating operation During heating operation, the flow direction switching mechanism 12 is in the state shown by the broken line in FIG. 1, the discharge side of the compressor 11 communicates with the gas side of the indoor heat exchanger 25, and the compressor 11 The suction side of the outdoor heat exchanger 13 communicates with the gas side of the outdoor heat exchanger 13.

When the compressor 11 is driven in such a state, the low-pressure gas refrigerant is compressed by the compressor 11 to become a high-pressure gas refrigerant, which is the discharge pipe 16b, the flow direction switching mechanism 12, the second gas refrigerant pipe 16e, and the gas. It is sent to the indoor heat exchanger 25 via the refrigerant connecting pipe GP and the gas refrigerant pipe 21. The high-pressure overheated gas refrigerant sent to the indoor heat exchanger 25 flows into the indoor heat exchanger 25 via the gas side inlet / outlet GH, and is condensed by exchanging heat with the indoor air to condense and become a high-pressure liquid refrigerant. After becoming (liquid refrigerant in an overcooled state), it flows out from the indoor heat exchanger 25 via the liquid side inlet / outlet LH. The refrigerant flowing out of the indoor heat exchanger 25 is sent to the expansion mechanism 14 via the liquid refrigerant pipe 22, the liquid refrigerant connecting pipe LP, and the liquid refrigerant pipe 16d. The high-pressure liquid refrigerant sent to the expansion mechanism 14 is depressurized according to the valve opening degree of the expansion mechanism 14 when passing through the expansion mechanism 14. The low-pressure refrigerant that has passed through the expansion mechanism 14 flows into the outdoor heat exchanger 13. The low-pressure refrigerant that has flowed into the outdoor heat exchanger 13 exchanges heat with the outdoor air and evaporates to become a low-pressure gas refrigerant, which is compressed via the first gas refrigerant pipe 16c, the flow direction switching mechanism 12, and the suction pipe 16a. It is sucked into the machine 11 again.

(3) Details of the indoor unit FIG. 2 is a perspective view of the indoor unit 20. FIG. 3 is a schematic cross-sectional view taken along the line III-III of FIG. 2 of the indoor unit 20 attached to the ceiling surface CL. FIG. 4 is a schematic view showing a schematic configuration of the indoor unit 20 in a bottom view.

The indoor unit 20 is a so-called ceiling-embedded air-conditioning indoor unit, and is installed on the ceiling of the space to be air-conditioned. The indoor unit 20 has a casing 30 that constitutes an outer shell.

Equipment such as an indoor heat exchanger 25 and an indoor fan 28 is housed in the casing 30. As shown in FIG. 3, the casing 30 is inserted into the opening formed in the ceiling surface CL of the target space, and is inserted into the attic space CS formed between the ceiling surface CL and the floor surface or roof of the upper floor. Will be installed. The casing 30 includes a top plate 31a, a side plate 31b, a bottom plate 31c, and a decorative panel 32.

The top plate 31a is a member constituting the top surface portion of the casing 30, and has a substantially octagonal shape in which long sides and short sides are alternately and continuously formed.

The side plate 31b is a member constituting the side surface portion of the casing 30, and has a substantially octagonal column shape corresponding to the shape of the top plate 31a. The side plate 31b has an opening for inserting (pulling in) the gas refrigerant connecting pipe GP and the liquid refrigerant connecting pipe LP into the casing 30, or for pulling out the gas refrigerant pipe 21 or the liquid refrigerant pipe 22 to the outside of the casing 30. 30a is formed (see the one-point chain line in FIG. 4).

The bottom plate 31c is a member constituting the bottom surface portion of the casing 30, and a substantially quadrangular large opening 311 is formed in the center (see FIG. 3). Further, a plurality of openings 312 are formed around the large opening 311 of the bottom plate 31c (see FIG. 3). A decorative panel 32 is attached to the lower surface side (target space side) of the bottom plate 31c.

The decorative panel 32 is a plate-shaped member exposed in the target space, and has a substantially square shape in a plan view. The decorative panel 32 is fitted and installed in the opening of the ceiling surface CL (see FIG. 3). The decorative panel 32 is formed with a suction port 33 and an outlet 34 for the indoor air flow AF. The suction port 33 is formed in a substantially square shape in the central portion of the decorative panel 32 at a position partially overlapping with the large opening 311 of the bottom plate 31c in a plan view. The air outlet 34 is formed around the suction port 33 so as to surround the suction port 33.

In the casing 30, a suction flow path FP1 for guiding the indoor airflow AF that has flowed into the casing 30 through the suction port 33 to the indoor heat exchanger 25, and an indoor airflow that has passed through the indoor heat exchanger 25. An outlet flow path FP2 that sends AF to the outlet 34 is formed. The outlet flow path FP2 is arranged outside the suction flow path FP1 so as to surround the suction flow path FP1.

In the casing 30, the indoor fan 28 is arranged in the central portion, and the indoor heat exchanger 25 is arranged so as to surround the indoor fan 28. The indoor fan 28 partially overlaps the suction port 33 in a plan view (see FIG. 4). The indoor heat exchanger 25 has a substantially quadrangular ring shape in a plan view, and is arranged so as to surround the suction port 33 and the outlet 34.

By arranging the suction port 33, the outlet 34, the suction flow path FP1, the outlet flow path FP2, the indoor heat exchanger 25, and the indoor fan 28 in the above-described manner, the indoor fan 28 is in operation and indoors. In the unit 20, the indoor airflow AF flows through the following path.

The indoor air flow AF generated by the indoor fan 28 flows into the casing 30 through the suction port 33 and is guided to the indoor heat exchanger 25 via the suction flow path FP1. The indoor airflow AF guided to the indoor heat exchanger 25 exchanges heat with the refrigerant in the indoor heat exchanger 25, and then is sent to the outlet 34 via the outlet flow path FP2, and is sent from the outlet 34 to the outlet 34. It is blown out into the target space.

In the following description, the direction in which the indoor airflow AF flows when passing through the indoor heat exchanger 25 is referred to as “air flow direction dr3 (see FIGS. 7 and 8)”. In the present embodiment, the air flow direction dr3 is the horizontal direction.

(4) Indoor heat exchanger The indoor heat exchanger 25 will be described.

(4-1) Configuration of Indoor Heat Exchanger FIG. 5 is a schematic view schematically showing the indoor heat exchanger 25 seen from the flat tube stacking direction dr2 of the flat multi-hole tube 45 described later. The flat tube stacking direction dr2 is an example of the first direction. Here, the flat tube stacking direction dr2 is the vertical direction. FIG. 5 is a schematic view of the indoor heat exchanger 25 as viewed from below. FIG. 6 is a perspective view of the indoor heat exchanger 25. FIG. 7 is a perspective view showing a part of the heat exchange surface 40. FIG. 8 is a schematic cross-sectional view taken along the line VIII-VIII of FIG. FIG. 9 is a schematic diagram schematically showing the configuration of the indoor heat exchanger 25.

(4-1-1) Refrigerant inlet / outlet for indoor heat exchanger 25 Refrigerant inlet / outlet for indoor heat exchanger 25 will be described.

As described above, the refrigerant flows into or out of the indoor heat exchanger 25 via the gas side inlet / outlet GH and the liquid side inlet / outlet LH (see FIG. 1). During heating operation (that is, when the indoor heat exchanger 25 is used as a condenser), the gas side inlet / outlet GH functions as an inlet for a refrigerant (mainly an overheated gas refrigerant), and the liquid side inlet / outlet LH functions as a refrigerant (mainly). It functions as an outlet for overcooled liquid refrigerant). On the other hand, during the cooling operation (that is, when the indoor heat exchanger 25 is used as an evaporator), the liquid side inlet / outlet LH functions as an inlet of the refrigerant, and the gas side inlet / outlet GH functions as a refrigerant (mainly an overheated gas refrigerant). Acts as an exit for.

The indoor heat exchanger 25 is formed with a plurality of (here, two) gas side inlets and outlets GH and a plurality of (here, two) liquid side inlets and outlets LH. Specifically, the indoor heat exchanger 25 is formed with a first gas side inlet / outlet GH1 and a second gas side inlet / outlet GH2 as gas side inlet / outlet GH (see FIG. 6). Further, the indoor heat exchanger 25 is formed with a first liquid side inlet / outlet LH1 and a second liquid side inlet / outlet LH2 as liquid side inlet / outlet LH (see FIG. 6). The first gas side inlet / outlet GH1 and the second gas side inlet / outlet GH2 are arranged above the first liquid side inlet / outlet LH1 and the second liquid side inlet / outlet LH2 (see FIG. 6).

(4-1-2) Heat Exchange Surface of Indoor Heat Exchanger Next, the heat exchange surface 40 of the indoor heat exchanger 25 will be described. In the indoor heat exchanger 25, heat exchange between the indoor air flow AF and the refrigerant is performed on the heat exchange surface 40. In the installed state, the indoor airflow AF passing through the heat exchange surface 40 has a wind speed distribution. In the indoor unit 20 of the present embodiment, the wind speed on the upper stage side of the indoor air flow AF passing through the heat exchange surface 40 is higher than the wind speed on the lower stage side.

The heat exchange surface 40 includes a front row first heat exchange surface 51, a front row second heat exchange surface 52, a front row third heat exchange surface 53, a front row fourth heat exchange surface 54, and a rear row first heat exchange surface 61, which will be described later. It includes a second heat exchange surface 62 in the back row, a third heat exchange surface 63 in the back row, and a fourth heat exchange surface 64 in the back row.

The indoor heat exchanger 25 has heat exchange surfaces 40 for exchanging heat with the indoor air flow AF on the windy side and the leeward side of the airflow direction dr3 of the indoor airflow AF. Specifically, the heat exchange surface 40 includes a front row heat exchange surface 55 arranged on the wind side in the air flow direction dr3 and a back row heat exchange surface 65 arranged on the leeward side in the air flow direction dr3. In other words, the indoor heat exchanger 25 has a front row heat exchange surface 55 (front row first heat exchange surface 51, front row second heat exchange surface 52, front row third heat exchange surface 53, and front row fourth heat exchange surface 54). The front row heat exchange section 50 arranged on the wind side in the air flow direction dr3, the back row heat exchange surface 65 (rear row first heat exchange surface 61, rear row second heat exchange surface 62, rear row third heat exchange surface 63, and so on. It has a fourth heat exchange surface 64) in the back row, and has a back row heat exchange unit 60 arranged on the leeward side of the air flow direction dr3. The front row heat exchange unit 50 and the back row heat exchange unit 60 will be described later.

In each heat exchange surface 40, the indoor heat exchanger 25 has a plurality of (19 in this case) flat multi-hole pipes 45 through which the refrigerant flows inside, and a plurality of heat transfer that promotes heat exchange between the refrigerant and the indoor air flow AF. It has a heat fin 48 (see FIGS. 7 and 8 and the like). The number of flat multi-hole tubes 45 shown here is merely an example and is not limited. The number of flat multi-hole pipes 45 may be appropriately changed according to design specifications and the like. For example, the number of flat multi-hole tubes 45 may be 18 or less or 20 or more.

Each flat multi-hole pipe 45 has a second end from the first end side (front row first header 56 side in the case of the front row heat exchange section 50, back row first header 66 side in the case of the back row heat exchange section 60). It extends toward the side (front row second header 57 side in the case of the front row heat exchange unit 50, back row second header 67 side in the case of the back row heat exchange unit 60) (see FIG. 9). Here, each flat multi-hole tube 45 extends so as to draw approximately four sides of a quadrilateral (see FIG. 6). Each flat multi-hole tube 45 is arranged so as to extend in a predetermined flat tube extension direction dr1 (here, a horizontal direction). A plurality of flat multi-hole tubes 45 are arranged side by side (stacked) at intervals in a predetermined flat tube stacking direction dr2 (here, in the vertical direction). The flat tube extension direction dr1 is a direction that intersects the flat tube stacking direction dr2 and the air flow direction dr3. The flat tube stacking direction dr2 is a direction that intersects the flat tube extending direction dr1 and the air flow direction dr3. In particular, here, the air flow direction dr3 is substantially orthogonal to the flat tube stacking direction dr2. In the present embodiment, the indoor heat exchanger 25 has heat exchange surfaces 40 on the windy side and the leeward side, and in the indoor heat exchanger 25, they are arranged in a plurality of rows (here, two rows) in the air flow direction dr3. The flat multi-hole pipes 45 are laminated in a plurality of stages in the flat pipe stacking direction dr2. The number of flat multi-hole pipes 45, the number of rows, and the number of stages of the heat exchange surface 40 can be appropriately changed according to the design specifications.

The flat multi-hole tube 45 is a flat tube configured to have a flat cross section. The flat multi-hole tube 45 is made of aluminum or an aluminum alloy. Inside the flat multi-hole tube 45, a plurality of refrigerant flow paths (flat tube flow paths 451) extending along the flat tube extension direction dr1 are formed (see FIG. 8). The plurality of flat pipe flow paths 451 are arranged so as to be arranged along the air flow direction dr3 in the flat multi-hole pipe 45 (see FIG. 8).

The heat transfer fin 48 is a flat plate-shaped member that increases the heat transfer area between the flat multi-hole tube 45 and the indoor air flow AF. The heat transfer fin 48 is made of aluminum or an aluminum alloy. The heat transfer fin 48 extends with the flat tube stacking direction dr2 as the longitudinal direction so as to intersect the flat multi-hole tube 45. The heat transfer fins 48 are formed with a plurality of slits 48a arranged side by side at intervals along the flat tube stacking direction dr2. A flat multi-hole tube 45 is inserted into each slit 48a (see FIG. 8).

Each heat transfer fin 48 is arranged on the heat exchange surface 40 together with the other heat transfer fins 48 at intervals along the flat tube extending direction dr1. In the present embodiment, the indoor heat exchanger 25 has heat exchange surfaces 40 on the windy side and the leeward side, and in the indoor heat exchanger 25, the heat transfer fins 48 extending along the flat tube stacking direction dr2 are air. Many are arranged in two rows along the flow direction dr3 and along the flat tube extension direction dr1. The number of heat transfer fins 48 on the heat exchange surface 40 of the indoor heat exchanger 25 is selected according to the length dimension of the flat tube extending direction dr1 of the flat multi-hole tube 45, and is appropriately selected according to the design specifications. It can be changed.

(4-1-3) Configuration of indoor heat exchanger The indoor heat exchanger 25 includes a plurality of (here, two) heat exchange units (front row heat exchange unit 50 and back row heat exchange unit 60) and a front row first header. It mainly has 56, a front row second header 57, a back row first header 66, a back row second header 67, a folded pipe 58, and a connecting pipe 70. These configurations will be described below.

Here, for convenience of explanation, the wind-up front row configuration (front row heat exchange unit 50, front row first header 56, front row second header 57, and folded pipe 58) in the air flow direction dr3 and the air flow direction dr3. The configuration of the indoor heat exchanger 25 will be described separately for the rear row configuration on the leeward side (rear row heat exchange unit 60, rear row first header 66 and rear row second header 67) and the connection pipe 70.

(4-1-3-1) Front Row Configuration FIG. 10 is a schematic diagram schematically showing a front row configuration including a front row heat exchange unit 50, a front row first header 56, a front row second header 57, and a folded pipe 58. ..

The front row heat exchange unit 50 has a front row heat exchange surface 55 as a heat exchange surface 40. The front row heat exchange surface 55 includes a front row first heat exchange surface 51, a front row second heat exchange surface 52, a front row third heat exchange surface 53, and a front row fourth heat exchange surface 54.

(4-1-3-1-1) Front row heat exchange section The flat multi-hole tube 45 included in the front row heat exchange surface 55 of the front row heat exchange section 50 is second from the first end side (front row first header 56). It extends toward the end side (front row second header 57). Each flat multi-hole tube 45 extends so as to draw approximately four sides of a quadrilateral. In other words, each flat multi-hole tube 45 is arranged in a substantially square shape. The front row first heat exchange surface 51, the front row second heat exchange surface 52, the front row third heat exchange surface 53, and the front row fourth heat exchange surface 54 are the front row first header 56 along the extending direction of the flat multi-hole tube 45. They are arranged side by side in this order from the side toward the front row second header 57 side.

The front row first heat exchange surface 51, the front row second heat exchange surface 52, the front row third heat exchange surface 53, and the front row fourth heat exchange surface 54 are arranged in a substantially four-sided shape in a plan view (see FIG. 5). .. Specifically, the front row first heat exchange surface 51 extends forward from the front row first header 56. The front row second heat exchange surface 52 extends to the right from the front end of the front row first heat exchange surface 51. The front row third heat exchange surface 53 extends rearward from the right end of the front row second heat exchange surface 52. The front row fourth heat exchange surface 54 extends from the rear end of the front row third heat exchange surface 53 to the left to the front row second header 57.

In the schematic diagram of FIG. 10 and the like, from the viewpoint of easy understanding, the front row first heat exchange surface 51, the front row second heat exchange surface 52, the front row third heat exchange surface 53, and the front row arranged in a four-sided shape. The fourth heat exchange surface 54 is drawn in a single plane.

(4-1-3-1-2) Front row first header The front row first header 56 joins a diversion header that diverts the refrigerant to each flat multi-hole pipe 45, or a refrigerant flowing out from each flat multi-hole pipe 45. A header tube that functions as a merging header or the like. The front row first header 56 extends in the vertical direction (vertical direction) as the longitudinal direction in the installed state.

The front row first header 56 is formed in a cylindrical shape, and the front row first header space Sa1 is formed therein (see FIG. 10). The front row first header 56 is connected to the end (rear end) of the front row first heat exchange surface 51 (see FIG. 6). The front row first header 56 is connected to one end of each flat multi-hole pipe 45 of the front row heat exchange section 50, and these flat multi-hole pipes 45 communicate with the front row first header space Sa1 (see FIG. 10).

A plurality of (here, two) horizontal partition plates 561 are arranged inside the first header 56 in the front row (see FIG. 10). The first header space Sa1 in the front row is partitioned by a horizontal partition plate 561 into a plurality of (three in this case) spaces in the flat tube stacking direction dr2. Specifically, the front row first header space Sa1 is partitioned by the horizontal partition plate 561 into the front row first space A1, the front row second space A2, and the front row third space A3 (see FIG. 10). The front row first space A1, the front row second space A2, and the front row third space A3 are arranged side by side in the order of the front row first space A1, the front row second space A2, and the front row third space A3 from the top.

A first gas side inlet / outlet GH1 is formed in the first header 56 in the front row (see FIG. 10). The first gas side inlet / outlet GH1 communicates with the first space A1 in the front row. A first gas refrigerant pipe 21a is connected to the first gas side inlet / outlet GH1 (see FIG. 10). The first space A1 in the front row is located on the most downstream side of the refrigerant flow in the indoor heat exchanger 25 during the cooling operation, and is located on the most upstream side of the refrigerant flow in the indoor heat exchanger 25 during the heating operation.

Further, a first liquid side inlet / outlet LH1 and a second liquid side inlet / outlet LH2 are formed in the front row first header 56 (see FIG. 10). The first liquid side inlet / outlet LH1 communicates with the second space A2 in the front row. The first liquid refrigerant pipe 22a is connected to the first liquid side inlet / outlet LH1 (see FIG. 10). The second liquid side inlet / outlet LH2 communicates with the third space A3 in the front row. A second liquid refrigerant pipe 22b is connected to the second liquid side inlet / outlet LH2 (see FIG. 10). The front row second space A2 and the front row third space A3 are located on the most downstream side of the refrigerant flow in the indoor heat exchanger 25 during the cooling operation, and are located on the most downstream side of the refrigerant flow in the indoor heat exchanger 25 during the heating operation. ..

(4-1-3-1-3) Front row second header The front row second header 57 is a diversion header that diverts the refrigerant to each flat multi-hole pipe 45, and a confluence that merges the refrigerant flowing out from each flat multi-hole pipe 45. It is a header tube that functions as a folded header or the like for folding back a header or a refrigerant flowing out from each flat multi-hole tube 45 to another flat multi-hole tube 45. The front row second header 57 extends in the vertical direction (vertical direction) as the longitudinal direction in the installed state.

The front row second header 57 is formed in a cylindrical shape, and the front row second header space Sa2 is formed therein (see FIG. 10). The front row second header 57 is connected to the end (left end) of the front row fourth heat exchange surface 54 (see FIG. 6). The front row second header 57 is connected to one end of each flat multi-hole tube 45 of the front row heat exchange section 50, and these flat multi-hole tubes 45 are communicated with the front row second header space Sa2 (see FIG. 10).

A plurality of (here, two) horizontal partition plates 571 are arranged in the second header 57 in the front row (see FIG. 10). The second header space Sa2 in the front row is partitioned by a horizontal partition plate 571 into a plurality of (three in this case) spaces in the flat tube stacking direction dr2. Specifically, the front row second header space Sa2 is partitioned by a horizontal partition plate 571 into a front row fourth space A4, a front row fifth space A5, and a front row sixth space A6 (see FIG. 10). The front row 4th space A4, the front row 5th space A5, and the front row 6th space A6 are arranged side by side in the order of the front row 4th space A4, the front row 5th space A5, and the front row 6th space A6 from the top.

The front row fourth space A4 communicates with the front row first space A1 of the front row first header 56 via a flat multi-hole tube 45 (see FIG. 10). Further, a first connection hole H1 is formed in a portion of the front row second header 57 corresponding to the front row fourth space A4. One end of the folded pipe 58 is connected to the first connection hole H1. The fourth space A4 in the front row and the folding pipe 58 are in communication with each other. The front row fourth space A4 communicates with the front row fifth space A5 via a folding pipe 58.

The front row fifth space A5 communicates with the front row second space A2 of the front row first header 56 via a flat multi-hole pipe 45 (see FIG. 10). Further, a second connection hole H2 is formed in a portion of the front row second header 57 corresponding to the front row fifth space A5. One end of the folding pipe 58 is connected to the second connection hole H2. The fifth space A5 in the front row and the folding pipe 58 are in communication with each other.

The front row sixth space A6 communicates with the front row third space A3 of the front row first header 56 via a flat multi-hole pipe 45 (see FIG. 10). Further, a third connection hole H3 is formed in a portion of the front row second header 57 corresponding to the front row sixth space A6. One end of the connection pipe 70 is connected to the third connection hole H3. The sixth space A6 in the front row and the connecting pipe 70 communicate with each other. The front row sixth space A6 communicates with the rear row second header space Sb2 in the rear row second header 67, which will be described later, via the connection pipe 70.

(4-1-3-1-4) Folded pipe The folded pipe 58 passes through the flat multi-hole pipe 45 and passes through any space in the front row second header 57 (here, the front row fourth space A4 or the front row fifth). It is a pipe for forming a folded flow path by folding back the refrigerant flowing into the space A5) and flowing it into another space (here, the front row fifth space A5 or the front row fourth space A4). In the present embodiment, the folded pipe 58 is connected to the front row second header 57 so that one end communicates with the front row fourth space A4, and the other end connects to the front row second header 57 so as to communicate with the front row fifth space A5. It is connected.

In the present embodiment, the folded-back pipe 58 is used to form the folded-back flow path, but the method for forming the folded-back flow path is not limited to such a method. For example, instead of providing the folded pipe 58, an opening is formed in the horizontal partition plate 571 that separates the front row fourth space A4 and the front row fifth space A5, and the front row fourth space A4 and the front row fifth space A5 are communicated with each other. A flow path may be formed.

(4-1-3-2) Back row configuration FIG. 11 is a schematic diagram schematically showing a back row configuration including a back row heat exchange unit 60, a back row first header 66, and a back row second header 67.

The back row heat exchange unit 60 has a back row heat exchange surface 65 as a heat exchange surface 40. The rear row heat exchange surface 65 includes a rear row first heat exchange surface 61, a rear row second heat exchange surface 62, a rear row third heat exchange surface 63, and a rear row fourth heat exchange surface 64.

(4-1-3-2-1) Back row heat exchange section The flat multi-hole tube 45 included in the back row heat exchange surface 65 of the back row heat exchange section 60 is second from the first end side (rear row first header 66). It extends toward the end side (second header 67 in the back row). Each flat multi-hole tube 45 extends so as to draw approximately four sides of a quadrilateral (arranged in a substantially square shape). The rear row first heat exchange surface 61, the rear row second heat exchange surface 62, the rear row third heat exchange surface 63, and the rear row fourth heat exchange surface 64 are the rear row first header 66 along the extending direction of the flat multi-hole tube 45. They are arranged side by side in this order from the side toward the second header 67 side in the back row.

The rear row first heat exchange surface 61, the rear row second heat exchange surface 62, the rear row third heat exchange surface 63, and the rear row fourth heat exchange surface 64 are arranged in a substantially four-sided shape in a plan view (see FIG. 5). .. Specifically, the rear row first heat exchange surface 61 extends forward from the rear row first header 66. The rear row second heat exchange surface 62 extends to the right from the front end of the rear row first heat exchange surface 61. The rear row third heat exchange surface 63 extends rearward from the right end of the rear row second heat exchange surface 62. The rear row fourth heat exchange surface 64 extends from the rear end of the rear row third heat exchange surface 63 to the left to the rear row second header 67.

The back row heat exchange surface 65 formed in a substantially four-sided shape is arranged adjacent to the front row heat exchange surface 55 so as to surround the front row heat exchange surface 55 (see FIG. 6). The rear row first heat exchange surface 61, the rear row second heat exchange surface 62, the rear row third heat exchange surface 63, and the rear row fourth heat exchange surface 64 are the front row first heat exchange surface 51 and the front row second heat exchange surface 52, respectively. , The front row third heat exchange surface 53 and the front row fourth heat exchange surface 54 are arranged so as to face each other.

In the schematic diagram of FIG. 11 and the like, from the viewpoint of easy understanding, the rear row first heat exchange surface 61, the rear row second heat exchange surface 62, the rear row third heat exchange surface 63, and the rear row arranged in a four-sided shape. The fourth heat exchange surface 64 is drawn in a single plane.

(4-1-3--2-2) Back row first header The back row first header 66 merges a diversion header that diverts the refrigerant into each flat multi-hole pipe 45, or a refrigerant flowing out from each flat multi-hole pipe 45. A header tube that functions as a merging header or the like. The rear row first header 66 extends in the vertical direction as the longitudinal direction in the installed state. The rear row first header 66 is arranged on the leeward side (left side in FIG. 6) of the front row first header 56 in the air flow direction dr3, adjacent to the front row first header 56.

The back row first header 66 is formed in a cylindrical shape, and the back row first header space Sb1 is formed therein (see FIG. 11). The rear row first header 66 is connected to the end (rear end) of the rear row first heat exchange surface 61 (see FIG. 6). The back row first header 66 is connected to one end of each flat multi-hole pipe 45 of the back row heat exchange section 60, and these flat multi-hole pipes 45 communicate with the back row first header space Sb1 (see FIG. 11).

A second gas side inlet / outlet GH2 is formed in the first header 66 in the back row (see FIG. 11). The second gas side inlet / outlet GH2 communicates with the first header space Sb1 in the rear row. A second gas refrigerant pipe 21b is connected to the second gas side inlet / outlet GH2 (see FIG. 11). The rear row first header space Sb1 is located on the most downstream side of the refrigerant flow in the indoor heat exchanger 25 during the cooling operation, and is located on the most upstream side of the refrigerant flow in the indoor heat exchanger 25 during the heating operation.

(4-1-3-2-3) Back row second header The back row second header 67 is a diversion header that diverts the refrigerant to each flat multi-hole pipe 45, and a confluence that merges the refrigerant flowing out from each flat multi-hole pipe 45. It is a header tube that functions as a folded header or the like for folding back a header or a refrigerant flowing out from each flat multi-hole tube 45 to another flat multi-hole tube 45. The second header 67 in the back row extends with the vertical direction as the longitudinal direction in the installed state. The rear row second header 67 is adjacent to the leeward side (rear side in FIG. 6) of the front row second header 57 in the air flow direction dr3.

The back row second header 67 is formed in a cylindrical shape, and the back row second header space Sb2 is formed therein (see FIG. 11). The back row second header 67 is connected to the end (left end) of the back row fourth heat exchange surface 64 (see FIG. 6). The back row second header 67 is connected to one end of each flat multi-hole tube 45 of the back row heat exchange unit 60, and these flat multi-hole tubes 45 are communicated with the back row second header space Sb2 (see FIG. 11).

The rear row second header space Sb2 communicates with the rear row first header space Sb1 via the flat multi-hole pipe 45 (see FIG. 11). A fourth connection hole H4 is formed in the second header 57 in the front row. One end of the connection pipe 70 is connected to the fourth connection hole H4. The back row second header space Sb2 communicates with the front row sixth space A6 of the front row second header 57 via the connection pipe 70.

(4-1-3-3) Connection pipe The connection pipe 70 is a refrigerant pipe that forms a flow path of the refrigerant between the front row heat exchange unit 50 and the back row heat exchange unit 60. The connection pipe 70 is a flow path for the refrigerant that communicates the front row sixth space A6 of the front row second header 57 and the rear row second header space Sb2 of the rear row second header 67.

(4-2) Refrigerant Path in Indoor Heat Exchanger A refrigerant path in the indoor heat exchanger 25 will be described. The “pass” here means a flow path of the refrigerant formed by communicating each element included in the indoor heat exchanger 25.

FIG. 12 is a schematic diagram schematically showing the path of the refrigerant formed in the indoor heat exchanger 25. In this embodiment, a plurality of paths are formed in the indoor heat exchanger 25. Specifically, the indoor heat exchanger 25 is formed with a first pass P1, a second pass P2, a third pass P3, and a fourth pass P4.

(4-2-1) 1st pass The 1st pass P1 is mainly a flow path of a refrigerant formed by a front row heat exchange unit 50, a front row first header 56, and a front row second header 57 (FIGS. 12 and 12). See FIG. 13 and the like). In the present embodiment, the first pass P1 is formed above the alternate long and short dash line L1 (see FIGS. 12 and 13 and the like) of the front row heat exchange section 50. The first pass P1 is mainly formed by a front row first space A1, a flat multi-hole tube 45 that communicates the front row first space A1 and the front row fourth space A4, and a front row fourth space A4.

The indoor airflow AF passing through the front row heat exchange unit 50 may have a wind velocity distribution. For example, the wind speed of the indoor air flow AF passing through the upper side of the front row heat exchange unit 50 is higher than the wind speed of the indoor air flow AF passing through the lower stage side of the front row heat exchange unit 50. For example, the wind speed of the indoor airflow AF passing above the one-point chain line L1 (see FIG. 10) of the front row heat exchange section 50 is higher than that of the indoor airflow AF passing below the one-point chain line L1.

During the cooling operation, the refrigerant flows from the front row fourth space A4 to the front row first space A1 in the first pass P1 (see FIG. 13).

Further, during the heating operation, the refrigerant flows from the front row first space A1 to the front row fourth space A4 in the first pass P1 (see FIG. 15). More specifically, during the heating operation, the gas refrigerant in a superheated state mainly flows from the first gas refrigerant pipe 21a through the first gas side inlet / outlet GH1 and into the front row first space A1. The gas refrigerant that has flowed into the first space A1 in the front row flows in from the end opening (gas refrigerant inlet / outlet 45aa, see FIG. 12) on the front row first space A1 side of the flat multi-hole pipe 45 of the first pass P1 and flows into the flat pipe. It passes through the road 451 and flows into the front row fourth space A4 from the end opening on the front row fourth space A4 side of the flat multi-hole pipe 45 of the first pass P1.

The flat multi-hole pipe 45 of the first pass P1 is an example of a gas-side flat multi-hole pipe in which a gas refrigerant inlet / outlet 45aa (see FIG. 12) is provided at one end (front row first header 56 side, first end side). be. The gas refrigerant inlet / outlet 45aa is the refrigerant inlet of the flat multi-hole tube 45 on the most upstream side in the refrigerant flow direction in the indoor heat exchanger 25 (when the indoor heat exchanger 25 functions as a condenser) during heating operation. be. That is, when the indoor heat exchanger 25 functions as a condenser, the gas refrigerant flowing from the gas refrigerant pipe 21 into the indoor heat exchanger 25 first flows through the gas-side flat multi-hole tube. Further, the gas refrigerant inlet / outlet 45aa is the refrigerant of the flat multi-hole pipe 45 on the most downstream side in the refrigerant flow direction in the indoor heat exchanger 25 (when the indoor heat exchanger 25 functions as an evaporator) during cooling operation. It is an exit. That is, when the indoor heat exchanger 25 functions as an evaporator, it finally flows through the gas-side flat multi-hole pipe and flows out from the indoor heat exchanger 25 to the liquid refrigerant pipe 22. In other words, the gas-side flat multi-hole tube is a flat multi-hole tube 45 connected to a space communicating with the gas-side inlet / outlet GH of the header. In the following, among the flat multi-hole pipes 45, the gas-side flat multi-hole pipes in particular will be referred to as gas-side flat multi-hole pipes 45a (see FIG. 10).

As shown in FIGS. 10 and 12, the one-point chain line L1 (horizontal partition plate 561 that separates the front row first space A1 and the front row second space A2, and the front row fourth space A4 and the front row fifth space A5 are separated. The height position where the horizontal partition plate 571 is arranged) is located between the twelfth flat multi-hole tube 45 and the thirteenth flat multi-hole tube 45 counting from the top. That is, in the present embodiment, the first pass P1 includes 12 flat multi-hole pipes 45 (gas side flat multi-hole pipe 45a) from the top.

(4-2-2) 2nd pass The 2nd pass P2 is mainly a flow path of the refrigerant formed by the front row heat exchange unit 50, the front row first header 56, and the front row second header 57. In the present embodiment, the second pass P2 is formed below the alternate long and short dash line L1 of the front row heat exchange section 50 and above the alternate long and short dash line L2 (see FIGS. 12 and 13 and the like). The second pass P2 is mainly formed by a front row second space A2, a flat multi-hole tube 45 communicating with the front row second space A2 and the front row fifth space A5, and a front row fifth space A5.

During the cooling operation, the refrigerant flows from the front row second space A2 to the front row fifth space A5 in the second pass P2 (see FIG. 13).

Further, during the heating operation, the refrigerant flows from the front row fifth space A5 toward the front row second space A2 in the second pass P2 (see FIG. 15). More specifically, during the heating operation, the refrigerant flowing through the first pass P1 (gas side flat multi-hole pipe 45a) and the folded pipe 58 flows into the front row fifth space A5 from the second connection hole H2. In the front row fifth space A5 (inside the front row second header 57), the refrigerant flowing out from the plurality of gas-side flat multi-hole pipes 45a joins. The refrigerant merging in the fifth space A5 in the front row (inside the second header 57 in the front row) is guided to the plurality of flat multi-hole pipes 45 in the second pass P2. Specifically, the refrigerant merged in the front row 5th space A5 flows in from the end opening on the front row 5th space A5 side of the flat multi-hole pipe 45 of the second pass P2 and passes through the flat pipe flow path 451. Then, it flows into the front row second space A2 from the end opening (liquid refrigerant inlet / outlet 45ba, see FIG. 12) on the front row second space A2 side of the flat multi-hole tube 45 of the second pass P2. The refrigerant flowing into the second space A2 in the front row during the heating operation is mainly a liquid refrigerant in a supercooled state.

Unlike the gas-side flat multi-hole pipe 45a, the flat multi-hole pipe 45 of the second pass P2 is provided with a liquid refrigerant inlet / outlet 45ba (see FIG. 12) at one end (front row first header 56 side, first end side). This is an example of a flat multi-hole tube on the liquid side. The liquid refrigerant inlet / outlet 45ba is the outlet of the refrigerant of the flat multi-hole tube 45 on the most downstream side in the refrigerant flow direction in the indoor heat exchanger 25 (when the indoor heat exchanger 25 functions as a condenser) during heating operation. be. That is, when the indoor heat exchanger 25 functions as a condenser, it finally flows through the liquid-side flat multi-hole pipe and flows out from the indoor heat exchanger 25 to the liquid refrigerant pipe 22. Further, the liquid refrigerant inlet / outlet 45ba is the refrigerant of the flat multi-hole tube 45 on the most upstream side in the refrigerant flow direction in the indoor heat exchanger 25 (when the indoor heat exchanger 25 functions as an evaporator) during cooling operation. It is the entrance. That is, when the indoor heat exchanger 25 functions as an evaporator, the liquid refrigerant flowing into the indoor heat exchanger 25 from the liquid refrigerant pipe 22 first flows through the liquid side flat multi-hole pipe. In other words, the liquid-side flat multi-hole tube 45 is a flat multi-hole tube 45 connected to a space communicating with the liquid-side inlet / outlet LH of the header. In the following, among the flat multi-hole pipes 45, the liquid-side flat multi-hole pipe is referred to as a liquid-side flat multi-hole pipe 45b (see FIG. 10).

As shown in FIGS. 10 and 12, the one-point chain line L2 (horizontal partition plate 561 that separates the front row second space A2 and the front row third space A3, and the front row fifth space A5 and the front row sixth space A6 are separated. The height position where the horizontal partition plate 571 is arranged) is located between the 16th flat multi-hole tube 45 and the 17th flat multi-hole tube 45 counting from the top. That is, in the present embodiment, the second pass P2 includes the 13th to 16th (that is, 4) flat multi-hole tubes 45 (liquid-side flat multi-hole tubes 45b) counting from the top.

(4-2-3) Third Pass The third pass P3 is mainly a flow path of the refrigerant formed by the front row heat exchange unit 50, the front row first header 56, and the front row second header 57. In the present embodiment, the third pass P3 is formed below the alternate long and short dash line L2 of the front row heat exchange section 50 (see FIGS. 12 and 13 and the like). The third pass P3 is mainly formed by a front row third space A3, a flat multi-hole tube 45 communicating with the front row third space A3 and the front row sixth space A6, and a front row sixth space A6.

During the cooling operation, the refrigerant flows from the front row third space A3 to the front row sixth space A6 in the third pass P3 (see FIG. 13).

Further, during the heating operation, the refrigerant flows from the front row sixth space A6 toward the front row third space A3 in the third pass P3 (see FIG. 15). More specifically, during the heating operation, the refrigerant flowing through the fourth pass P4 (gas side flat multi-hole pipe 45a) and the connection pipe 70, which will be described later, flows into the front row sixth space A6 from the third connection hole H3. The refrigerant flowing into the sixth space A6 in the front row is guided to the plurality of flat multi-hole pipes 45 of the third pass P3. Specifically, the refrigerant that has flowed into the 6th space A6 in the front row flows in from the end opening on the 6th space A6 side in the front row of the flat multi-hole tube 45 of the 3rd pass P3, and passes through the flat tube flow path 451. , It flows into the front row third space A3 from the end opening (liquid refrigerant inlet / outlet 45ba) on the front row third space A3 side of the flat multi-hole pipe 45 of the third pass P3. The refrigerant flowing into the third space A3 in the front row during the heating operation is mainly a liquid refrigerant in a supercooled state. The flat multi-hole tube 45 of the third pass P3 is a liquid-side flat multi-hole tube 45b.

As shown in FIGS. 10 and 12, the third pass P3 is the 17th to 19th (that is, 3) flat multi-hole tubes 45 (liquid-side flat multi-hole tubes 45b) counted from the top. include.

(4-2-4) 4th pass The 4th pass P4 is mainly a flow path of a refrigerant formed by a back row heat exchange unit 60, a back row first header 66, and a back row second header 67 (FIGS. 12 and 12). See FIG. 14 and the like). The fourth pass P4 mainly consists of a flat multi-hole pipe 45 that communicates the first header space Sb1 in the back row, the first header space Sb1 in the back row, and the second header space Sb2 in the back row, and the second header space Sb2 in the back row. It is formed.

During the cooling operation, the refrigerant flows from the second header space Sb2 in the back row toward the first header space Sb1 in the back row in the fourth pass P4 (see FIG. 14).

Further, during the heating operation, the refrigerant flows from the back row first header space Sb1 to the back row second header space Sb2 in the fourth pass P4 (see FIG. 16). More specifically, during the heating operation, the gas refrigerant mainly in the overheated state passes from the second gas refrigerant pipe 21b through the second gas side inlet / outlet GH2 and flows into the rear row first header space Sb1. The gas refrigerant flowing into the rear row first header space Sb1 flows in from the end opening (gas refrigerant inlet / outlet 45aa) on the rear row first header space Sb1 side of the flat multi-hole pipe 45 of the fourth pass P4, and flows into the flat pipe flow path 451. It flows into the rear row second header space Sb2 from the end opening on the rear row second header space Sb2 side of the flat multi-hole pipe 45 of the first pass P1. In the back row second header space Sb2 (inside the back row second header 67), the refrigerant flowing out from the plurality of gas-side flat multi-hole pipes 45a joins. The refrigerant merging in the second header space Sb2 in the back row (inside the second header 67 in the back row) is guided to the plurality of liquid-side flat multi-hole pipes 45b of the third pass P3 via the connection pipe 70 and the sixth space A6 in the front row. ..

The flat multi-hole pipe 45 of the fourth pass P4 is a gas-side flat multi-hole pipe 45a (see FIG. 10). As shown in FIGS. 10 and 12, the fourth pass P4 includes a total of 19 flat multi-hole tubes 45 (gas-side flat multi-hole tubes 45a).

In other words, the 19 flat multi-hole pipes 45 of the back row heat exchange unit 60 are all gas-side flat multi-hole pipes 45a constituting the fourth pass P4. On the other hand, in the flat multi-hole tube 45 of the front row heat exchange portion 50, 12 from the top are gas-side flat multi-hole tubes 45a, and 7 from the bottom are liquid-side flat multi-hole tubes 45b.

That is, in the indoor heat exchanger 25 of the present embodiment, the number of gas-side flat multi-hole tubes 45a included in the front row heat exchange section (front row heat exchange section 50) on the wind side in the air flow direction dr3 is on the leeward side. It has a configuration that the number is smaller than the number of gas-side flat multi-hole tubes 45a included in the heat exchange section (rear row heat exchange section 60) in the last row.

Further, the indoor heat exchanger 25 of the present embodiment has a configuration in which a plurality of heat exchange units (front row heat exchange unit 50 and rear row heat exchange unit 60) include a gas-side flat multi-hole tube 45a.

Further, in the indoor heat exchanger 25 of the present embodiment, the total number of gas-side flat multi-hole tubes 45a is 31 (back row heat exchange section 60:19, front row heat exchange section 50:12), and the liquid side flat multi-hole tube 45a is provided. It has a configuration that the total number of tubes 45b is more than 7 (all are front row heat exchange sections 50).

Further, the indoor heat exchanger 25 of the present embodiment has a configuration in which the gas side flat multi-hole tube 45a is provided with a gas refrigerant inlet / outlet port 45aa on the first header 56, 66 side.

The merit that the indoor heat exchanger 25 has these configurations will be described later.

(4-3) Flow of Refrigerant in Indoor Heat Exchanger (4-3-1) During Cooling Operation FIG. 13 is a schematic diagram schematically showing the flow of refrigerant in the front row heat exchange unit 50 during cooling operation. .. FIG. 14 is a schematic diagram schematically showing the flow of the refrigerant in the back row heat exchange unit 60 during the cooling operation. In FIGS. 13 and 14, the broken line arrow indicates the flow direction of the refrigerant.

During the cooling operation, the refrigerant flowing through the first liquid refrigerant pipe 22a flows into the second pass P2 of the front row heat exchange unit 50 via the first liquid side inlet / outlet LH1. The liquid refrigerant flowing into the second pass P2 passes through the liquid-side flat multi-hole pipe 45b of the second pass P2 while exchanging heat with the indoor air flow AF and being heated. The refrigerant heated in the liquid-side flat multi-hole pipe 45b of the second pass P2 and becoming a two-phase state ((a state in which the liquid phase and the gas phase are mixed) in the middle of the liquid-side flat multi-hole pipe 45b is the second in the front row. After merging at the header 57 (in the fifth space A5 in the front row), the liquid flows into the first pass P1 through the turn-back pipe 58. The refrigerant flowing into the first pass P1 exchanges heat with the indoor air flow AF and is heated. The gas phase refrigerant passes through the gas-side flat multi-hole pipe 45a of the first pass P1 and flows out to the first gas refrigerant pipe 21a via the first gas-side inlet / outlet GH1.

Further, during the cooling operation, the refrigerant flowing through the second liquid refrigerant pipe 22b flows into the third pass P3 of the front row heat exchange unit 50 via the second liquid side inlet / outlet LH2. The liquid refrigerant flowing into the third pass P3 passes through the liquid-side flat multi-hole pipe 45b of the third pass P3 while exchanging heat with the indoor air flow AF and being heated. The refrigerant heated in the liquid-side flat multi-hole pipe 45b of the third pass P3 and entering a two-phase state in the middle of the liquid-side flat multi-hole pipe 45b merges at the front row second header 57 (in the front row sixth space A6). After that, it flows into the fourth pass P4 of the back row heat exchange unit 60 via the connection pipe 70. The refrigerant flowing into the 4th pass P4 passes through the gas side flat multi-hole tube 45a of the 4th pass P4 while being heated by exchanging heat with the indoor air flow AF, and the gas phase refrigerant passes through the 2nd gas side inlet / outlet GH2. It flows out to the second gas refrigerant pipe 21b.

During the cooling operation (particularly when the operation is in a steady state), in the indoor heat exchanger 25, the flat tube flow path 451 in the first pass P1 (particularly, the front row first header 56 in the first pass P1). A region (superheated region SH1) through which a superheated refrigerant flows is formed in the flat tube flow path 451 on the side (for example, the flat tube flow path 451 included in the first pass P1 of the first heat exchange surface 51 in the front row). The region other than the superheated region SH1 of the flat tube flow path 451 in the 1-pass P1 is mainly a two-phase region through which a two-phase refrigerant (a refrigerant in which a liquid phase and a gas phase are mixed) flows. Flat tube flow path 451 (in particular, the flat tube flow path 451 on the rear row first header 66 side in the fourth pass P4 (for example, the flat tube flow path included in the fourth pass P4 of the rear row first heat exchange surface 61). In 451), a region (superheated region SH2) through which the superheated refrigerant flows is formed. The region other than the superheated region SH2 of the flat tube flow path 451 in the fourth pass P4 is mainly a two-phase region through which the two-phase refrigerant flows. It becomes an area.

In the indoor heat exchanger 25 of the present embodiment, the front row heat exchange section 50 and the back row heat exchange section 60 are provided with a gas-side flat multi-hole pipe 45a (a gas refrigerant outlet is provided at one end in the flow direction of the refrigerant during cooling operation). It has a configuration that includes the piping). Further, in the indoor heat exchanger 25 of the present embodiment, the total number of gas-side flat multi-hole pipes 45a in which the refrigerant heated by the liquid-side flat multi-hole pipe 45b is further heated during the cooling operation is the total number of liquid-side flat multi-hole pipes 45a. It has a configuration that is larger than the total number of tubes 45b. Therefore, even when the degree of superheat in the refrigeration cycle is controlled to a relatively large value during the cooling operation in which the indoor heat exchanger 25 is used as an evaporator, deterioration of performance is likely to be suppressed.

(4-3-2) During heating operation In the indoor heat exchanger 25 during heating operation, the overheated gas refrigerant flows in from the gas side inlet / outlet GH, is cooled by the heat exchange units 50 and 60, and is in the overcooled state. The refrigerant flows out from the liquid side inlet / outlet LH.

FIG. 15 is a schematic diagram schematically showing the flow of the refrigerant in the front row heat exchange unit 50 during the heating operation. FIG. 16 is a schematic diagram schematically showing the flow of the refrigerant in the back row heat exchange unit 60 during the heating operation. In FIGS. 15 and 16, the broken line arrow indicates the flow direction of the refrigerant.

During the heating operation, the superheated gas refrigerant flowing through the first gas refrigerant pipe 21a flows into the front row first space A1 of the front row first header 56 through the first gas side inlet / outlet GH1. The gas refrigerant flowing into the first space A1 in the front row passes through the flat pipe flow path 451 of the gas-side flat multi-hole pipe 45a of the first pass P1 while exchanging heat with the indoor air flow AF and being cooled. The refrigerant cooled in the gas-side flat multi-hole pipe 45a of the first pass P1 and in a two-phase state in the middle of the gas-side flat multi-hole pipe 45a flows into the front row fourth space A4. The refrigerant that has flowed into the front row fourth space A4 flows into the front row fifth space A5 via the turn-back pipe 58. The refrigerant flowing into the fifth space A5 in the front row exchanges heat with the indoor air flow AF and passes through the flat pipe flow path 451 of the liquid-side flat multi-hole pipe 45b of the second pass P2 while being in a supercooled state, and passes through the second space in the front row. It flows out to the first liquid refrigerant pipe 22a via A2 and the first liquid side inlet / outlet LH1.

Further, during the heating operation, the overheated gas refrigerant flowing through the second gas refrigerant pipe 21b flows into the rear row first header space Sb1 through the second gas side inlet / outlet GH2. The gas refrigerant flowing into the first header space Sb1 in the back row passes through the flat pipe flow path 451 of the gas-side flat multi-hole pipe 45a of the fourth pass P4 while exchanging heat with the indoor air flow AF and being cooled. The refrigerant cooled in the gas-side flat multi-hole pipe 45a of the fourth pass P4 and in a two-phase state in the middle of the gas-side flat multi-hole pipe 45a flows into the second header space Sb2 in the rear row. The refrigerant that has flowed into the second header space Sb2 in the back row flows into the sixth space A6 in the front row of the second header 57 in the front row via the connection pipe 70. The refrigerant flowing into the 6th space A6 in the front row exchanges heat with the indoor air flow AF and passes through the flat pipe flow path 451 of the liquid side flat multi-hole pipe 45b of the 3rd pass P3 while being in an overcooled state, and is in the 3rd space in the front row. It flows out to the second liquid refrigerant pipe 22b via A3 and the second liquid side inlet / outlet LH2.

Inside the front row second header 57, there is a space (front row fifth space A5) into which the refrigerant flowing out of the gas side flat multi-hole pipe 45a of the front row heat exchange section 50 flows in, and a gas side flat multi-hole hole of the back row heat exchange section 60. The space (front row sixth space A6) into which the refrigerant flowing out of the pipe 45a flows in is isolated. In other words, inside the front row second header 57, a horizontal partition plate 571 that separates the refrigerant flowing out from the gas-side flat multi-hole pipe 45a by the heat exchange section is arranged.

During the heating operation (particularly when the operation is in a steady state), in the indoor heat exchanger 25, the flat tube flow path 451 in the first pass P1 (particularly, the front row first header 56 in the first pass P1). A region (overheating) in which an overheated refrigerant flows in the flat tube flow path 451 of the gas-side flat multi-hole tube 45a on the side (for example, the flat tube flow path 451 included in the first pass P1 of the first heat exchange surface 51 in the front row). Region SH3) is formed. The region other than the superheated region SH3 of the flat pipe flow path 451 of the first pass P1 is mainly a two-phase region through which the two-phase refrigerant flows. Further, the flat tube flow path 451 in the fourth pass P4 (in particular, the flat tube flow path 451 on the rear row first header 66 side in the fourth pass P4 (for example, in the fourth pass P4 of the rear row first heat exchange surface 61). A region (superheated region SH4) through which a superheated refrigerant flows is formed in the included flat tube flow path 451). The region other than the superheated region SH4 of the flat tube flow path 451 of the fourth pass P4 is mainly two-phase. The superheated region SH3 and the superheated region SH4 are two-phase regions through which the refrigerant flows. The superheated region SH3 and the superheated region SH4 are examples of gas regions in which the gas refrigerant flows, which are formed in the vicinity of the gas refrigerant inlet / outlet port 45aa of the gas-side flat multi-hole pipe 45a.

In the indoor heat exchanger 25 of the present embodiment, as described above, the gas-side flat multi-hole pipe 45a is provided with a gas refrigerant inlet / outlet port 45aa on the first header 56, 66 side. Therefore, as shown in FIGS. 15 and 16, the superheated region SH3 of the front row heat exchange unit 50 and the superheated region SH4 of the rear row heat exchange unit 60 are on the same end side (first header) of the flat multi-hole pipe 45. It is located on the 56, 66 side). That is, the superheated region SH3 of the front row heat exchange unit 50 and the superheated region SH4 of the rear row heat exchange unit 60 are arranged so as to overlap each other in the air flow direction dr3. Further, the flow direction of the refrigerant flowing through the superheated region SH3 of the front row heat exchange unit 50 and the refrigerant flowing through the superheated region SH4 of the rear row heat exchange unit 60 are the same (that is, parallel flow).

In the indoor heat exchanger 25 of the present embodiment, the front row heat exchange section 50 is a gas side flat multi-hole pipe 45a (first gas) provided with a gas refrigerant inlet / outlet 45aa on the first end side (front row first header 56 side). Side flat multi-hole tube) is included. Further, the back row heat exchange unit 60 includes a gas-side flat multi-hole pipe 45a (first gas-side flat multi-hole pipe) provided with a gas refrigerant inlet / outlet 45aa on the first end side (back row first header 66 side). In the indoor heat exchanger 25 of the present embodiment, the gas side flat multi-hole tube 45a is arranged above the front row heat exchange section 50, and the gas side flat multi-hole tube 45a is arranged in the rear row heat exchange section 60 in the entire height direction. The hole tube 45a is arranged. Therefore, the gas side flat multi-hole pipe 45a (first gas side flat multi-hole pipe) of the front row heat exchange portion 50 is on the leeward side in the air flow direction on the first gas side in the first direction (flat pipe stacking direction dr2). The gas refrigerant inlet / outlet 45aa is located at the same position as the flat multi-hole pipe (that is, at the same height as the flat multi-hole pipe on the first gas side of the front row heat exchange section 50) and on the first end side (rear row first header 66 side). Only the gas-side flat multi-hole pipe 45a of the provided back row heat exchange portion 60 is arranged. Further, the heat exchange section is not arranged on the leeward side of the gas side flat multi-hole tube 45a (first gas side flat multi-hole tube) of the back row heat exchange section 60 in the air flow direction.

Further, in the indoor heat exchanger 25 of the present embodiment, the number of gas-side flat multi-hole tubes 45a included in the heat exchange section (front row heat exchange section 50) in the front row on the wind side is the heat in the last row on the leeward side. The number is smaller than the number of gas-side flat multi-hole tubes 45a included in the exchange section (rear row heat exchange section 60). Therefore, the length He3 of the superheated region SH3 in the flat tube stacking direction dr2 is smaller than the length He4 of the superheated region SH4 (see FIGS. 15 and 16). Further, the heat exchange efficiency between the refrigerant and the indoor air flow AF in the front row heat exchange section 50 on the wind side is the heat exchange efficiency between the refrigerant and the indoor air flow AF in the rear row heat exchange section 60 on the leeward side that has passed through the front row heat exchange section 50. Higher than heat exchange efficiency between. Therefore, the length Le3 of the superheated region SH3 in the flat tube extending direction dr1 is smaller than the length Le4 of the superheated region SH4 (see FIGS. 15 and 16). Therefore, the area of the superheated region SH3 is smaller than the area of the superheated region SH4 (see FIGS. 15 and 16). In other words, when viewed from the air flow direction dr3, the entire superheated region SH3 is included in the superheated region SH4.

In other words, the flat multi-hole tube 45 is not provided with the two-phase / liquid region through which the two-phase refrigerant or the liquid-phase refrigerant flows on the leeward side of the superheated region SH3 in the air flow direction dr3. Therefore, the indoor air flow AF that has exchanged heat with the high-temperature gas refrigerant can suppress the deterioration of the condensation performance of the indoor heat exchanger 25 due to the heat exchange with the low-temperature gas refrigerant.

Further, during the heating operation (particularly when the operation is in a steady state), in the indoor heat exchanger 25, the flat tube flow path 451 in the second pass P2 (particularly, the front row first in the second pass P2). In the flat tube flow path 451 on the header 56 side (for example, the flat tube flow path 451 included in the second pass P2 of the first heat exchange surface 51 in the front row), the region where the overcooled refrigerant flows (overcooling region SC1). Is formed. The region other than the overcooling region SC1 of the flat tube flow path 451 in the second pass P2 is mainly a two-phase region through which the two-phase refrigerant flows. Further, in the indoor heat exchanger 25, the flat tube flow path 451 in the third pass P3 (particularly, the flat tube flow path 451 on the front row first header 56 side in the third pass P3 (for example, the front row first heat exchange). In the flat tube flow path 451)) included in the third pass P3 of the surface 51, a region (supercooled region SC2) through which the supercooled refrigerant flows is formed. The region other than the supercooled region SC2 of the flat pipe flow path 451 in the third pass P3 is mainly a two-phase region through which the two-phase refrigerant flows. In the present embodiment, the liquid-side flat multi-hole pipe 45b is a flat multi-hole pipe (first liquid-side flat multi-hole pipe) provided with a liquid refrigerant inlet / outlet 45ba on the first end side (front row first header 56 side). ).

Here, since the front row heat exchange section 50 provided with the liquid-side flat multi-hole tube 45b is the heat exchange section located on the most windy side in the air flow direction dr3, the air flow direction of the liquid-side flat multi-hole tube 45b. The heat exchange unit is not arranged on the wind side of dr3. In other words, the two-phase / gas region through which the flat multi-hole tube 45 flows is not arranged on the wind side of the supercooled regions SC1 and SC2 in the air flow direction dr3. Therefore, here, it is possible to suppress that the refrigerant once cooled to a predetermined supercooling degree is heated by the air warmed by the two-phase refrigerant or the gas refrigerant on the windward side, and it is possible to suppress the deterioration of performance. Further, when viewed from the air side, it is possible to suppress that the air warmed by the two-phase refrigerant or the gas refrigerant is cooled by the refrigerant supercooled on the leeward side during the heating operation, and it is possible to suppress the deterioration of the heating performance.

(5) Features (5-1)
The indoor heat exchanger 25 of the above embodiment has a plurality of rows (here, two rows) of heat exchange units 50 and 60. In the indoor heat exchanger 25, a plurality of rows of heat exchange units 50 and 60 are arranged so as to be overlapped with each other in the air flow direction dr3. In each of the heat exchange units 50 and 60, the flat multi-hole pipe 45 extending from the first end side (first header 56, 66 side) toward the second end side (second header 57, 67 side) and flowing the refrigerant inside. Are arranged side by side in the flat tube stacking direction dr2. The flat tube stacking direction dr2 is an example of the first direction. In the present embodiment, the flat tube stacking direction dr2 is the vertical direction. The number of gas-side flat multi-hole pipes 45a provided at one end of the gas refrigerant inlet / outlet 45aa included in the front row heat exchange section 50 in the front row on the leeward side is included in the rear row heat exchange section 60 in the last row on the leeward side. It is less than the number of flat multi-hole tubes 45a on the gas side.

In the main indoor heat exchanger 25, for example, when the gas refrigerant flows into the gas refrigerant inlet / outlet 45aa of the gas side flat multi-hole tube 45a (when the indoor heat exchanger 25 is used as a condenser), the front row in the front row. Compared to the heat exchange unit 50, the ratio of cooling the high temperature gas refrigerant in the rear row heat exchange unit 60 in the last row is higher. The high-temperature gas refrigerant can exchange heat relatively efficiently with the air having a high temperature on the leeward side (heated by the refrigerant on the leeward side). Therefore, as compared with the case where it is not configured in this way, the indoor heat exchanger 25 as a whole can efficiently exchange heat between the refrigerant and the air.

Further, when viewed from the side of the air heated in the indoor heat exchanger 25 functioning as a condenser, in the present embodiment, the indoor heat exchanger 25 receives the air heated by the front row heat exchange section 50 on the wind side. Further, since it can be heated by a high-temperature gas refrigerant on the leeward side, a high blowout temperature can be realized and the condenser performance can be improved.

(5-2)
In the indoor heat exchanger 25 of the above embodiment, the two rows of heat exchange portions 50 and 60 include a gas-side flat multi-hole tube 45a.

Here, by arranging the gas-side flat multi-hole pipes 45a in the heat exchange portions 50 and 60 in a plurality of rows, it is possible to realize a path taking with a high degree of freedom. Therefore, it is easy to obtain performance both when the indoor heat exchanger 25 functions as an evaporator and when it functions as a condenser, and it is easy to realize a highly efficient indoor heat exchanger 25.

Further, with such a configuration, even when the degree of overheating in the refrigeration cycle is controlled to a relatively large value during the cooling operation in which the indoor heat exchanger 25 is used as an evaporator, the performance is deteriorated. It is easy to be suppressed.

(5-3)
In the indoor heat exchanger 25 of the above embodiment, the flat multi-hole pipe 45 includes a liquid-side flat multi-hole pipe 45b provided with a liquid refrigerant inlet / outlet 45ba at one end, unlike the gas-side flat multi-hole pipe 45a.

Further, in the indoor heat exchanger 25 of the above embodiment, the total number of gas-side flat multi-hole tubes 45a is larger than the total number of liquid-side flat multi-hole tubes 45b.

Here, by having more gas-side flat multi-hole pipes 45a than liquid-side flat multi-hole pipes 45b, it is an operating condition that a large degree of overheating is taken when the indoor heat exchanger 25 is used as an evaporator. However, the deterioration of performance can be suppressed.

(5-4)
In the indoor heat exchanger 25 of the above embodiment, the gas-side flat multi-hole tube 45a is provided with a gas refrigerant inlet / outlet 45aa on the first end side (here, the first headers 56 and 66 sides).

Here, the gas refrigerant inlet / outlet 45aa is provided on the first end side of each of the plurality of rows of the gas-side flat multi-hole pipes 45a. Therefore, the region of the gas-side flat multi-hole tube 45a (overheating region) through which the high-temperature gas refrigerant flows and the region of the gas-side flat multi-hole tube 45a through which the lower temperature refrigerant flows are adjacent to each other to generate heat. The occurrence of loss is likely to be suppressed.

In particular, here, the superheat region SH4 formed when the indoor heat exchanger 25 functions as a condenser is larger than the superheat region SH3 formed on the wind side thereof (when viewed along the air flow direction dr3). Since the entire superheated region SH3 is included in the superheated region SH4), it is easy to avoid heat exchange of once heated air with a refrigerant having a relatively low temperature (two-phase refrigerant or liquid refrigerant), and heat is generated. The occurrence of loss is likely to be suppressed.

(5-5)
In the indoor heat exchanger 25 of the above embodiment, the front row second header 57 and the front row second header 57 as an example of the merging portion that merges the refrigerants flowing out from the plurality of gas-side flat multi-hole pipes 45a and guides them to the liquid-side flat multi-hole pipe 45b. A back row second header 67 is provided.

(5-6)
The indoor heat exchanger 25 of the above embodiment includes a front row second header 57 as an example of a header tube that guides the refrigerant flowing out from the gas-side flat multi-hole tube 45a to a plurality of liquid-side flat multi-hole tubes 45b. Inside the front row second header 57, a horizontal partition plate that separates the refrigerant flowing out from the gas-side flat multi-hole pipe 45a into heat exchange portions 50 and 60 (divided into a front row fifth space A5 and a front row sixth space A6). 571 is arranged. The horizontal partition plate 571 is an example of a partition plate.

Here, different refrigerants of the heat exchange units 50 and 60, in other words, refrigerants having different states, can be guided to different liquid-side flat multi-hole pipes 45b.

(5-7)
In the indoor heat exchanger 25 of the above embodiment, the liquid-side flat multi-hole tube 45b is a liquid-side flat multi-hole tube provided with a liquid refrigerant inlet / outlet 45ba on the first end side (front row first header 56 side). That is, the liquid-side flat multi-hole tube 45b is an example of the first liquid-side flat multi-hole tube. The heat exchange portion is not arranged on the wind side of the liquid side flat multi-hole tube 45b in the air flow direction dr3.

Here, when the condenser is used, it is possible to prevent the once cooled refrigerant from being heated by the air warmed by the two-phase refrigerant or the gas refrigerant on the windward side, and it is possible to suppress the deterioration of performance. Further, when viewed from the air side, it is possible to suppress that the air warmed by the two-phase refrigerant or the gas refrigerant is cooled by the refrigerant supercooled on the leeward side during the heating operation, and it is possible to suppress the deterioration of the heating performance.

(5-8)
In the indoor heat exchanger 25 of the above embodiment, in the indoor heat exchanger 25, the gas side flat multi-hole pipe 45a (first gas) provided with the gas refrigerant inlet / outlet 45aa on the first end side (front row first header 56 side). Side flat multi-hole tube) is included. Further, the back row heat exchange unit 60 includes a gas-side flat multi-hole pipe 45a (first gas-side flat multi-hole pipe) provided with a gas refrigerant inlet / outlet 45aa on the first end side (back row first header 66 side). On the leeward side of the gas side flat multi-hole pipe 45a (first gas side flat multi-hole pipe) of the front row heat exchange section 50 in the air flow direction, the first gas side flat multi-hole pipe in the first direction (flat pipe stacking direction dr2) A gas refrigerant inlet / outlet 45aa is provided at the same position as the hole pipe (that is, at the same height as the first gas side flat multi-hole pipe of the front row heat exchange unit 50) and on the first end side (rear row first header 66 side). Only the gas-side flat multi-hole tube 45a of the rear row heat exchange section 60 is arranged. Further, the heat exchange section is not arranged on the leeward side of the gas side flat multi-hole tube 45a (first gas side flat multi-hole tube) of the back row heat exchange section 60 in the air flow direction.

Here, when the condenser of the indoor heat exchanger 25 is used, the indoor air flow AF that exchanges heat with the high temperature gas refrigerant exchanges heat with the relatively low temperature gas refrigerant, so that the condensation performance of the indoor heat exchanger 25 deteriorates. Can be suppressed.

(5-9)
In the indoor heat exchanger 25 of the above embodiment, the gas side flat multi-hole tube 45a is formed with superheated regions SH3 and SH4 through which the gas refrigerant flows in the vicinity of the gas refrigerant inlet / outlet port 45aa. The superheated regions SH3 and SH4 are examples of gas regions. A two-phase / liquid region through which a two-phase refrigerant or a liquid-phase refrigerant flows is not arranged in the flat multi-hole tube 45 on the leeward side in the air flow direction dr3 of the superheated regions SH3 and SH4. Here, the superheated region SH4 is arranged on the leeward side in the air flow direction dr3 of the superheated region SH3. Further, the heat exchange portion is not arranged on the leeward side in the air flow direction dr3 of the superheated region SH4.

With such a configuration, the occurrence of heat loss is likely to be suppressed.

(5-10)
The air conditioner 100 as an example of the refrigerating device of the above embodiment has an indoor heat exchanger 25 and a blower for supplying air to the indoor heat exchanger 25. The indoor fan 28 is an example of a blower. A plurality of rows of heat exchange units 50 and 60 of the indoor heat exchanger 25 are arranged along the air flow direction dr3 generated by the indoor fan 28 as an example of the blower.

(6) Modification Example The above embodiment can be appropriately modified as shown in the following modification examples. In addition, each modification may be applied in combination with another modification as long as there is no contradiction.

(6-1) Modification 1A
In the above embodiment, the front row fourth space A4 and the front row fifth space A5 are connected by a folded pipe 58, and the front row sixth space A6 and the back row second header space Sb2 are connected by a connecting pipe 70. Further, the first liquid refrigerant pipe 22a is connected to the front row second space A2, and the second liquid refrigerant pipe 22b is connected to the front row third space A3.

Instead of this, as in the indoor heat exchanger 25a of FIG. 17, the front row fourth space A4 of the front row second header 57 and the front row second space A2 of the front row first header 56 are connected by a connecting pipe 58a, and the front row The front row third space A3 and the rear row second header space Sb2 of the first header 56 may be connected by a connection pipe 70a. Further, the first liquid refrigerant pipe 22a is connected to the front row fifth space A5 of the front row second header 57, and the second liquid refrigerant pipe 22b is connected to the front row sixth space A6 of the front row second header 57.

By being connected in this way, the directions in which the refrigerant flows are the same in all the flat multi-hole pipes 45 during the cooling operation and the heating operation. For example, FIG. 18 shows the flow of the refrigerant in the flat multi-hole pipe 45 of the first pass P1 to the fourth pass P4 during the heating operation (in addition, in FIG. 18, the connection pipe 58a and the connection pipe 70a are shown. Is omitted).

As a result, the superheated regions SH3 and SH4 are arranged on the first header 56 and 66 side, and the supercooled regions SC1 and SC2 are arranged on the second header 57 and 67 side. As a result, since the superheated areas SH3 and the superheated area SH4 and the supercooled areas SC1 and SC2 are arranged apart from each other (because they are not adjacent to each other), the occurrence of heat loss is particularly likely to be suppressed.

(6-2) Modification 1B
In the above embodiment, the front row heat exchange unit 50 has a gas side flat multi-hole pipe 45a and a liquid side flat multi-hole pipe 45b, and the back row heat exchange unit 60 has only a gas side flat multi-hole pipe 45a. However, the form of the heat exchanger according to the present disclosure is not limited to the configuration of the above embodiment.

For example, in the indoor heat exchanger, like the indoor heat exchanger 25b, only the liquid-side flat multi-hole pipe 45b is provided in the front row heat exchanger 50 so that the refrigerant flows as shown in FIG. 19 during the heating operation. Only the gas-side flat multi-hole tube 45a may be arranged in the heat exchange unit 60.

In this way, the number of gas-side flat multi-hole tubes 45a included in the front row heat exchange section 50 is smaller than the number of gas-side flat multi-hole tubes 45a included in the back row heat exchange section 60, thereby making the room indoor. When the heat exchanger 25b is used as a condenser, heat exchange can be efficiently performed between the refrigerant and the air. Then, it is possible to improve the condenser performance and realize a high blowing temperature from the indoor unit 20 during the heating operation.

(6-3) Modification 1C
In the above embodiment, in the front row first header 56, the front row first space A1, the front row second space A2, and the front row third space A3 are configured to be arranged in this order from top to bottom. Further, in the above embodiment, in the front row second header 57, the front row fourth space A4, the front row fifth space A5, and the front row sixth space A6 are configured to be arranged in this order from top to bottom. There is. That is, in the paths formed in the front row heat exchange unit 50, the first pass P1 is arranged at the uppermost stage, the second pass P2 is arranged at the middle stage, and the third pass P3 is arranged at the lowest stage.

However, the arrangement of the spaces A1, A2, A3 in the front row first header 56, the arrangement of the spaces A4, A5, A6 in the front row second header 57, and the arrangement of the paths P1, P2, P3 in the front row heat exchange unit 50. Is not limited to that of the above embodiment. It may be appropriately changed as long as it exhibits the same effect as a part or all of the effect of the above embodiment.

For example, in the front row first header 56, the front row first space A1, the front row second space A2, and the front row third space A3 may be configured to be arranged in this order from the bottom to the top. Then, in the front row second header 57, the front row fourth space A4, the front row fifth space A5, and the front row sixth space A6 may be configured to be arranged in this order from the bottom to the top. As a result, as for the paths formed in the front row heat exchange unit 50, the first pass P1 may be arranged at the bottom, the second pass P2 may be arranged at the middle, and the third pass P3 may be arranged at the top.

That is, in the above embodiment, the supercooled region (SC1, SC2) is located in the front row heat exchange portion 50 where the wind speed of the passing indoor airflow AF is smaller than the other portions (lower portion). .. However, the supercooling region is not limited to such an aspect, and the supercooling region is formed in a portion of the front row heat exchange portion 50 in which the wind velocity of the passing indoor airflow AF is the same as or higher than that of the other portion. May be good.

Further, for example, the second pass P2 may be arranged at the uppermost stage, the first pass P1 at the middle stage, and the third pass P3 at the lowermost stage.

When the position of the path is changed, the formation position (connection position of the pipe) of the openings (GH1, GH2, LH1, LH2, H1-H4) communicating with the path is also changed as appropriate. Just do it.

However, the path arrangement is preferably designed to satisfy the characteristics of the above embodiment (for example, the characteristics of (5-7), (5-8) and (5-9)).

(6-4) Modification 1D
In the above embodiment, the first pass P1 has 12 flat multi-hole tubes 45 (gas side flat multi-hole tube 45a), and the second pass P2 has four flat multi-hole tubes 45 (liquid side flat multi-hole tube 45b). ), The third pass P3 has three flat multi-hole tubes 45 (liquid-side flat multi-hole tubes 45b), respectively. However, the number of flat multi-hole tubes 45 included in each of the paths P1 to P3 shown in the above embodiment is not limited to the present disclosure, and the number may be appropriately determined according to the design specifications and the like. ..

However, regarding the number and arrangement of the gas-side flat multi-hole pipe 45a and the liquid-side flat multi-hole pipe 45b, the number of gas-side flat multi-hole pipes 45a included in the heat exchange portion in the front row on the wind side is the last on the leeward side. It is preferably designed to be smaller than the number of gas-side flat multi-hole tubes 45a included in the heat exchange section of the row. Further, the number and arrangement of the gas-side flat multi-hole tube 45a and the liquid-side flat multi-hole tube 45b are the features of the above embodiment (for example, (5-1) to (5-3), (5-7) to (5-7) to ( It is preferably designed to satisfy the characteristics) of 5-9).

(6-5) Modification 1E
In the above embodiment, the case where the flat tube extending direction dr1 of the indoor heat exchanger 25 is the horizontal direction and the flat tube stacking direction dr2 is the vertical direction in the installed state has been described. However, the flat tube extension direction dr1 and the flat tube stacking direction dr2 are not limited to the above directions. For example, the indoor heat exchanger 25 may be configured and arranged so that the flat tube extending direction dr1 is in the vertical direction and the flat tube stacking direction dr2 is in the horizontal direction in the installed state.

Further, in the above embodiment, the case where the air flow direction dr3 is the horizontal direction has been described. However, the air flow direction dr3 is not limited to this, and can be appropriately changed depending on the configuration mode and the installation mode of the indoor heat exchanger 25.

(6-6) Modification 1F
In the above embodiment, the front row second header 57 and the back row second header 67 are configured separately, and similarly, the front row first header 56 and the back row first header 66 are configured separately. However, the present invention is not limited to this, and in the indoor heat exchanger 25, a plurality of header collecting tubes arranged adjacent to each other (for example, the front row second header 57 and the back row second header 67, or the front row first header 56 and the back row). The first header 66) may be integrally configured. That is, a plurality of header collecting pipes arranged adjacent to each other are composed of one header collecting pipe, and the internal space of the header collecting pipe is set in the longitudinal direction (for example, the vertical direction) of the header collecting pipe or in the longitudinal direction. In the direction intersecting with (for example, the horizontal direction), the space may be divided into spaces by a partition plate as in the above embodiment. With this configuration, it is possible to reduce the number of header tubes.

(6-7) Modification 1G
In the above embodiment, the indoor heat exchanger 25 is arranged so as to surround the indoor fan 28. However, the indoor heat exchanger 25 does not necessarily have to be arranged so as to surround the indoor fan 28, and its shape and arrangement are appropriately changed as long as the heat exchange between the indoor air flow AF and the refrigerant is possible. Is possible.

(6-8) Modification 1H
In the above embodiment, as an example of the heat exchanger of the present disclosure, the indoor heat exchanger 25 mounted on the ceiling-embedded indoor unit 20 has been described. However, the heat exchanger of the present disclosure is not limited to the indoor heat exchanger 25 mounted on the ceiling-embedded indoor unit 20.

For example, the indoor unit of the air conditioner is various types of indoor units other than the ceiling-embedded type, such as a ceiling-hung type fixed to the ceiling surface CL, a wall-mounted type installed on a side wall, a duct type, and a floor-standing type. You may. Further, the indoor unit may be a type that blows air in all directions like the indoor unit 20 of the above embodiment, or may be, for example, an indoor unit that blows air in two directions or one direction.

Further, the shape of the heat exchange portion of the indoor heat exchanger is not limited to the shape of the front row heat exchange portion 50 and the back row heat exchange portion 60. For example, as shown in FIG. 32, the indoor heat exchanger may have a plurality of rows of flat plate-shaped heat exchange portions in which the stacking direction of the flat multi-hole pipes is inclined with respect to the vertical direction. The indoor unit in FIG. 32 is a ceiling-hung type). Further, for example, in the indoor heat exchanger, as shown in FIG. 33, a plurality of rows of heat exchange portions formed in a V shape in a side view so as to cover a fan (for example, a cross flow fan) are arranged side by side. It may be (the indoor unit in FIG. 33 is a wall-mounted type). In addition, the shape of the indoor heat exchanger and the like may be appropriately selected according to the type and the like of the indoor unit.

(6-9) Modification 1I
In the above embodiment, the case where the indoor heat exchanger 25, which is an example of the heat exchanger of the present disclosure, is applied to the air conditioner 100 as an example of the refrigerating device (refrigerating cycle device) has been described as an example.

However, the features of the heat exchangers of the present disclosure are widely applicable to heat exchangers in which heat exchange between air and a refrigerant is performed. For example, the heat exchanger of the present disclosure is characterized by the outdoor heat exchanger 13 of the air conditioner 100 (for example, a substantially L-shaped heat exchanger as shown in FIG. 34, in which a flat multi-hole tube is the first. It may be applied to a heat exchanger) having a plurality of rows of heat exchange units arranged side by side in the direction and having the plurality of rows of heat exchange units stacked in the air flow direction.

Further, the refrigerating apparatus to which the heat exchanger of the present disclosure is applied is not limited to the air conditioner 100. For example, the refrigerating apparatus may be a refrigerating apparatus for low temperature used in a refrigerating / refrigerating container, a warehouse, a showcase, or the like, or an apparatus such as a hot water supply device or a heat pump chiller.

(6-10) Modification 1J
In the above embodiment, the air conditioner 100 is a device capable of performing both cooling operation and heating operation. However, the present invention is not limited to this, and the refrigerating apparatus of the present disclosure may be an air conditioner that performs only one of heating operation and cooling operation. That is, the heat exchanger of the present disclosure does not have to be a heat exchanger that functions as a condenser and an evaporator, but may be a heat exchanger that functions only as a condenser in an air conditioner, or an air conditioner. It may be a heat exchanger that functions only as an evaporator. In this case, the refrigerant circuit RC may not be provided with the flow direction switching mechanism 12.

In the air conditioner 100, when the indoor heat exchanger 25 functions only as a condenser or only as an evaporator, the gas refrigerant inlet / outlet 45aa is either the inlet or the outlet of the gas refrigerant, and the liquid refrigerant inlet / outlet 45ba is the liquid. Functions as either an inlet or an outlet for the refrigerant. Here, in the indoor heat exchanger 25, even when the gas refrigerant inlet / outlet 45aa is used only as one of the gas refrigerant inlets and outlets, it is referred to as a gas refrigerant inlet / outlet, and the liquid refrigerant inlet / outlet 45ba is used as one of the liquid refrigerant inlets or outlets. Even when it is used only, it shall be referred to as a liquid refrigerant inlet / outlet.

<Second Embodiment>
The indoor heat exchanger 125 according to the second embodiment of the heat exchanger of the present disclosure will be described. Since the refrigerating apparatus has the same configuration as the air conditioner 100 of the first embodiment when the indoor heat exchanger 125 is used, the description of the parts other than the indoor heat exchanger 125 will be omitted here.

(1) Indoor heat exchanger (1-1) Configuration of indoor heat exchanger FIG. 20 is a schematic diagram schematically showing the indoor heat exchanger 125 seen from the flat tube stacking direction dr2 of the flat multi-hole tube 45. be. FIG. 21 is a schematic diagram schematically showing the indoor heat exchanger 125. FIG. 22 is a schematic diagram schematically showing the path of the refrigerant formed in the indoor heat exchanger 125.

The indoor heat exchanger 125 includes heat exchange units 150, 160, 180 (front row heat exchange unit 150, middle row heat exchange unit 180, and rear row heat exchange unit 160) arranged in three rows in the air flow direction dr3. Have. That is, the indoor heat exchanger 25 has two rows of front row heat exchange units 50 and back row heat exchange units 60, whereas the indoor heat exchanger 125 has front row heat exchange units 150 and back row heat exchange units 160. It differs from the indoor heat exchanger 25 in that the middle row heat exchanger 180 is arranged between the two. In addition, the configuration of the front row heat exchange unit 150 and the back row heat exchange unit 160 is such that the middle row heat exchange unit 180 is arranged between the front row heat exchange unit 150 and the back row heat exchange unit 160, and the front row includes passing and the like. Although it is partially different from the heat exchange unit 50 and the back row heat exchange unit 60, it is common in many respects. Therefore, here, the differences between the front row heat exchange unit 150 and the back row heat exchange unit 160 and the front row heat exchange unit 50 and the back row heat exchange unit 60 will be mainly described, and the same points will be basically explained. Omit. Further, since the middle row heat exchange unit 180 has many similar points to the front row heat exchange unit 50 and the back row heat exchange unit 60, it is the same as the front row heat exchange unit 50 and the back row heat exchange unit 60 in order to avoid duplication of explanation. The description of the points will be omitted.

(1-1-1) Refrigerant inlet / outlet for indoor heat exchanger Refrigerant flows into or out of the indoor heat exchanger 125 via the gas side inlet / outlet GH and the liquid side inlet / outlet LH.

Similarly to the indoor heat exchanger 25, the indoor heat exchanger 125 also has a first gas side inlet / outlet GH1 and a second gas side inlet / outlet GH2 formed as gas side inlet / outlet GH (see FIG. 21). Further, the indoor heat exchanger 125 is formed with a first liquid side inlet / outlet LH1 and a second liquid side inlet / outlet LH2 as liquid side inlet / outlet LH (see FIG. 21). The first gas side inlet / outlet GH1 and the second gas side inlet / outlet GH2 are arranged above the first liquid side inlet / outlet LH1 and the second liquid side inlet / outlet LH2 (see FIG. 21).

(1-1-2) Configuration of indoor heat exchanger The indoor heat exchanger 125 mainly has a plurality of (here, three) heat exchange units (front row heat exchange unit 150, middle row heat exchange unit 180, and back row heat). Exchange unit 160), front row first header 156, front row second header 157, middle row first header 186, middle row second header 187, back row first header 166, back row second header 167, It has connection pipes 171 and 172. These configurations will be described below.

Here, for convenience of explanation, the front row configuration on the wind side of the air flow direction dr3 (front row heat exchange unit 150, front row first header 156, and front row second header 157) and the leeward side of the air flow direction dr3. The back row configuration (back row heat exchange unit 160, back row first header 166 and back row second header 167) and the middle row configuration (middle row heat exchange unit 180, middle row first) arranged between the front row configuration and the back row configuration. The header 186, the middle row second header 187), and the connecting pipes 171 and 172 will be described separately. As described above, the same points as in the first embodiment will be omitted.

(1-1-2-1) Front Row Configuration FIG. 23 is a schematic diagram schematically showing a front row configuration including a front row heat exchange unit 150, a front row first header 156, and a front row second header 157.

(1-1-2-1-1) Front row heat exchange section The front row heat exchange section 150 has a front row heat exchange surface 155 as a heat exchange surface 40. The front row heat exchange surface 155 includes a front row first heat exchange surface 151, a front row second heat exchange surface 152, a front row third heat exchange surface 153, and a front row fourth heat exchange surface 154. The front row heat exchange surface 155, the front row first heat exchange surface 151, the front row second heat exchange surface 152, the front row third heat exchange surface 153, and the front row fourth heat exchange surface 154 are the front row heat exchange portions 50 of the first embodiment. The configuration is the same as that of the front row heat exchange surface 55, the front row first heat exchange surface 51, the front row second heat exchange surface 52, the front row third heat exchange surface 53, and the front row fourth heat exchange surface 54. Is omitted.

(1-1-2-1-2) Front row first header The front row first header 156 is the front row first header 56 in that only one horizontal partition plate 561 is arranged in the inner front row first header space Sa1. (See FIG. 23). The first header space Sa1 in the front row is divided into two spaces in the flat tube stacking direction dr2 by the horizontal partition plate 561. Specifically, the front row first header space Sa1 is partitioned by the horizontal partition plate 561 into the front row first space A11 and the front row second space A12 (see FIG. 23). The front row first space A11 is arranged above the front row second space A12.

A first liquid side inlet / outlet LH1 and a second liquid side inlet / outlet LH2 are formed in the first header 156 in the front row (see FIG. 23). The first liquid side inlet / outlet LH1 communicates with the first space A11 in the front row. The first liquid refrigerant pipe 22a is connected to the first liquid side inlet / outlet LH1 (see FIG. 23). The second liquid side inlet / outlet LH2 communicates with the second space A12 in the front row. A second liquid refrigerant pipe 22b is connected to the second liquid side inlet / outlet LH2 (see FIG. 23). The front row first space A11 and the front row second space A12 are located on the most downstream side of the refrigerant flow in the indoor heat exchanger 125 during the cooling operation, and are located on the most downstream side of the refrigerant flow in the indoor heat exchanger 125 during the heating operation. ..

(1-1-2-1-3) Front row second header The front row second header 157 also has a front row second header 57 in that only one horizontal partition plate 571 is arranged in the inner front row second header space Sa2. (See FIG. 23). The second header space Sa2 in the front row is divided into two spaces in the flat tube stacking direction dr2 by the horizontal partition plate 571. Specifically, the front row second header space Sa2 is partitioned into the front row third space A13 and the front row fourth space A14 by a horizontal partition plate 571 (see FIG. 23). The front row third space A13 is arranged above the front row fourth space A14.

The front row third space A13 communicates with the front row first space A11 of the front row first header 156 via a flat multi-hole tube 45 (see FIG. 23). A second connection hole H12 is formed in a portion of the front row second header 157 corresponding to the front row third space A13. One end of the second connection pipe 172 is connected to the second connection hole H12, and the front row third space A13 and the second connection pipe 172 communicate with each other. The front row third space A13 communicates with the rear row second header space Sb2 via the second connection pipe 172.

The front row fourth space A14 communicates with the front row second space A12 of the front row first header 156 via a flat multi-hole pipe 45 (see FIG. 23). A first connection hole H11 is formed in a portion of the front row second header 157 corresponding to the front row fourth space A14. One end of the first connection pipe 171 is connected to the first connection hole H11, and the front row fourth space A14 and the first connection pipe 171 are in communication with each other. The front row fourth space A14 communicates with the middle row second header space Sc2 via the first connection pipe 171.

(1-1-2-2) Middle Row Configuration FIG. 24 is a schematic diagram schematically showing a front row configuration including a middle row heat exchange unit 180, a middle row first header 186, and a middle row second header 187. be.

(1-1-2-2-1) Middle row heat exchange unit The middle row heat exchange unit 180 has a middle row heat exchange surface 185 as a heat exchange surface 40. The middle row heat exchange surface 185 includes a middle row first heat exchange surface 181 and a middle row second heat exchange surface 182, a middle row third heat exchange surface 183, and a middle row fourth heat exchange surface 184. The middle row heat exchange surface 185 formed in a substantially four-sided shape is arranged adjacent to the front row heat exchange surface 155 so as to surround the front row heat exchange surface 155 (see FIG. 20). The first heat exchange surface 181 in the middle row, the second heat exchange surface 182 in the middle row, the third heat exchange surface 183 in the middle row, and the fourth heat exchange surface 184 in the middle row are the first heat exchange surface 151 in the front row and the second heat exchange surface in the front row, respectively. It is arranged so as to face the heat exchange surface 152, the front row third heat exchange surface 153, and the front row fourth heat exchange surface 154.

Since the physical configuration of the middle row heat exchange unit 180 is the same as that of the front row heat exchange unit 150, detailed description thereof will be omitted here.

(1-1-2-2-2) Middle row first header The middle row first header 186 is a diversion header that diverts the refrigerant to each flat multi-hole pipe 45, or a refrigerant flowing out from each flat multi-hole pipe 45. It is a header tube that functions as a merging header or the like to be merged. The middle row first header 186 extends in the vertical direction as the longitudinal direction in the installed state. The middle row first header 186 is arranged on the leeward side (left side in FIG. 20) of the front row first header 156 in the air flow direction dr3, adjacent to the front row first header 156.

The middle row first header 186 is formed in a cylindrical shape, and the middle row first header space Sc1 is formed therein (see FIG. 24). The middle row first header 186 is connected to the end (rear end) of the middle row first heat exchange surface 181 (see FIG. 20). The middle row first header 186 is connected to one end of each flat multi-hole pipe 45 of the middle row heat exchange unit 180, and these flat multi-hole pipes 45 are communicated with the middle row first header space Sc1 (FIG. 24). reference).

A first gas side inlet / outlet GH1 is formed in the first header 186 in the middle row (see FIG. 24). The first gas side inlet / outlet GH1 communicates with the first header space Sc1 in the middle row. A first gas refrigerant pipe 21a is connected to the first gas side inlet / outlet GH1 (see FIG. 24). The first header space Sc1 in the middle row is located on the most downstream side of the refrigerant flow in the indoor heat exchanger 125 during the cooling operation, and is located on the most upstream side of the refrigerant flow in the indoor heat exchanger 125 during the heating operation.

(1-1-2-2-3) Middle row second header The middle row second header 187 is a diversion header that divides the refrigerant into each flat multi-hole pipe 45, and joins the refrigerant flowing out from each flat multi-hole pipe 45. It is a header tube that functions as a merging header or a folded header for folding back the refrigerant flowing out from each flat multi-hole tube 45 to another flat multi-hole tube 45. The middle row second header 187 extends in the vertical direction as the longitudinal direction in the installed state. The middle row second header 187 is adjacent to the leeward side (rear side in FIG. 20) of the front row second header 157 in the air flow direction dr3.

The middle row second header 187 is formed in a cylindrical shape, and the middle row second header space Sc2 is formed therein (see FIG. 24). The middle row second header 187 is connected to the end (left end) of the middle row fourth heat exchange surface 184 (see FIG. 20). The middle row second header 187 is connected to one end of each flat multi-hole pipe 45 of the middle row heat exchange portion 180, and these flat multi-hole pipes 45 are communicated with the middle row second header space Sc2 (FIG. 24). reference).

The middle row second header space Sc2 communicates with the middle row first header space Sc1 of the middle row first header 186 via a flat multi-hole tube 45 (see FIG. 24). A third connection hole H13 is formed in the second header 187 in the middle row. One end of the first connection pipe 171 is connected to the third connection hole H13. The middle row second header space Sc2 communicates with the front row fourth space A14 of the front row second header 57 via the first connection pipe 171.

(1-1-2-3) Back row configuration FIG. 25 is a schematic diagram schematically showing a front row configuration including a back row heat exchange unit 160, a back row first header 166, and a back row second header 167.

(1-1-2-3-1) Back row heat exchange unit The physical configuration of the back row heat exchange unit 160 is the same as that of the back row heat exchange unit 60.

The difference from the back row heat exchange section 60 of the back row heat exchange section 160 is that the back row heat exchange surface 165 formed in a substantially four-sided shape is adjacent to the middle row heat exchange surface 185 so as to surround the middle row heat exchange surface 185. (See FIG. 20). The rear row first heat exchange surface 161 and the rear row second heat exchange surface 162, the rear row third heat exchange surface 163, and the rear row fourth heat exchange surface 164 are the middle row first heat exchange surface 181 and the middle row second heat exchange surface, respectively. It is arranged so as to face the surface 182, the third heat exchange surface 183 in the middle row, and the fourth heat exchange surface 184 in the middle row.

(1-1-2-3-2) Back row 1st header The back row 1st header 166 is located on the leeward side (left side in FIG. 20) of the middle row 1st header 186 in the air flow direction dr3, and the middle row 1st header 186. It is placed adjacent to. Since other points are the same as those of the first header 66 in the back row, the description thereof will be omitted.

(1-1-2-3-3) Back row second header The difference from the back row second header 67 of the back row second header 167 will be mainly described.

The back row second header 167 is arranged adjacent to the leeward side (rear side in FIG. 20) of the middle row second header 187 in the air flow direction dr3.

The rear row second header space Sb2 communicates with the rear row first header space Sb1 via the flat multi-hole pipe 45 (see FIG. 25). A fourth connection hole H14 is formed in the second header 167 in the back row. One end of the second connection pipe 172 is connected to the fourth connection hole H14. The back row second header space Sb2 communicates with the front row third space A13 of the front row second header 157 via the second connection pipe 172 (see FIG. 21).

(1-1-2-4) Connection pipe The first connection pipe 171 is a refrigerant pipe that forms a flow path for the refrigerant between the front row heat exchange section 150 and the middle row heat exchange section 180. The first connection pipe 171 is a flow path of a refrigerant that communicates the front row fourth space A14 of the front row heat exchange unit 150 and the middle row second header space Sc2 of the middle row second header 187.

The second connection pipe 172 is a refrigerant pipe that forms a flow path of the refrigerant between the front row heat exchange unit 150 and the back row heat exchange unit 160. The second connection pipe 172 is a flow path for the refrigerant that communicates the front row third space A13 of the front row heat exchange unit 150 and the rear row second header space Sb2 of the rear row second header 167.

(1-2) Refrigerant path in the indoor heat exchanger The refrigerant path in the indoor heat exchanger 125 will be described.

FIG. 22 is a schematic diagram schematically showing the path of the refrigerant formed in the indoor heat exchanger 125. In this embodiment, a plurality of paths are formed in the indoor heat exchanger 125. Specifically, the indoor heat exchanger 125 is formed with a first pass P11, a second pass P12, a third pass P13, and a fourth pass P14.

(1-2-1) First Pass In the present embodiment, the first pass P11 is formed above the one-point chain line L3 (see FIG. 26 and the like) of the front row heat exchange unit 150. The first pass P1 is mainly formed by a front row first space A11, a flat multi-hole tube 45 communicating the front row first space A11 and the front row third space A13, and a front row third space A13.

During the cooling operation, the refrigerant flows from the front row first space A11 to the front row third space A13 in the first pass P11.

Further, during the heating operation, the refrigerant flows from the front row third space A13 toward the front row first space A11 in the first pass P11 (see FIG. 26). More specifically, during the heating operation, the refrigerant flowing through the fourth pass P14 (gas side flat multi-hole pipe 45a) and the second connection pipe 172, which will be described later, flows into the front row third space A13 from the second connection hole H12. do. The refrigerant flowing into the front row third space A13 (inside the front row second header 57) is guided to the plurality of flat multi-hole pipes 45 of the first pass P11. The refrigerant in the front row third space A13 flows in from the end opening on the front row third space A13 side of the flat multi-hole pipe 45 of the first pass P11, passes through the flat pipe flow path 451 and is flattened in the first pass P11. It flows into the front row first space A11 from the end opening (liquid refrigerant inlet / outlet 45ba) on the front row first space A11 side of the multi-hole pipe 45. The refrigerant flowing into the first space A11 in the front row during the heating operation is mainly a liquid refrigerant in a supercooled state.

The flat multi-hole tube 45 of the first pass P11 is a liquid-side flat multi-hole tube 45b. Since the description has been given in the first embodiment, the description of the liquid-side flat multi-hole tube 45b will be omitted. The number of flat multi-hole tubes 45 in the first pass P11 is 11, for example, as shown in FIG. 22, but the number of tubes may be appropriately determined.

(1-2-2) Second Pass In the present embodiment, the second pass P12 is formed below the one-point chain line L3 (see FIG. 26 and the like) of the front row heat exchange unit 150. The second pass P12 is mainly formed by a front row second space A12, a flat multi-hole tube 45 communicating the front row second space A12 and the front row fourth space A14, and a front row fourth space A14.

During the cooling operation, the refrigerant flows from the front row second space A12 to the front row fourth space A14 in the second pass P12.

Further, during the heating operation, the refrigerant flows from the front row fourth space A14 toward the front row second space A12 in the second pass P12 (see FIG. 26). More specifically, during the heating operation, the refrigerant flowing through the third pass P13 (gas side flat multi-hole pipe 45a) and the first connection pipe 171, which will be described later, flows into the front row fourth space A14 from the first connection hole H11. do. The refrigerant that has flowed into the front row fourth space A14 (inside the front row second header 57) is guided to the plurality of flat multi-hole pipes 45 of the second pass P12. The refrigerant in the front row fourth space A14 flows in from the end opening on the front row fourth space A14 side of the flat multi-hole pipe 45 of the second pass P12, passes through the flat pipe flow path 451 and is flattened in the second pass P12. It flows into the front row second space A12 from the end opening (liquid refrigerant inlet / outlet 45ba) on the front row first space A11 side of the multi-hole pipe 45. The refrigerant flowing into the second space A12 in the front row during the heating operation is mainly a liquid refrigerant in an overcooled state.

The flat multi-hole tube 45 of the second pass P12 is a liquid-side flat multi-hole tube 45b. The number of flat multi-hole tubes 45 in the second pass P12 is, for example, eight as shown in FIG. 22, but the number may be appropriately determined.

(1-2-3) Third pass The third pass P13 is a flat multi-hole that mainly communicates the first header space Sc1 in the middle row, the first header space Sc1 in the middle row, and the second header space Sc2 in the middle row. It is formed by a tube 45 and a middle row second header space Sc2.

During the cooling operation, the refrigerant flows from the second header space Sc2 in the middle row toward the first header space Sc1 in the middle row in the third pass P13.

Further, during the heating operation, the refrigerant flows from the first header space Sc1 in the middle row toward the second header space Sc2 in the middle row in the third pass P13 (see FIG. 27). More specifically, during the heating operation, the gas refrigerant mainly in the overheated state passes from the first gas refrigerant pipe 21a through the first gas side inlet / outlet GH1 and flows into the middle row first header space Sc1. The gas refrigerant flowing into the middle row first header space Sc1 flows in from the end opening (gas refrigerant inlet / outlet 45aa) on the middle row first header space Sc1 side of the flat multi-hole pipe 45 of the third pass P13, and flows into the flat pipe flow. It passes through the road 451 and flows into the middle row second header space Sc2 from the end opening on the middle row second header space Sc2 side of the flat multi-hole tube 45 of the third pass P13. In the middle row second header space Sc2 (inside the middle row second header 187), the refrigerant flowing out from the plurality of gas-side flat multi-hole pipes 45a joins. The refrigerant merged in the second header space Sc2 in the middle row (inside the second header 187 in the middle row) passes through the first connection pipe 171 and the fourth space A14 in the front row, and a plurality of liquid-side flat multi-hole pipes 45b of the second pass P12. Is guided to.

The flat multi-hole pipe 45 of the third pass P13 is a gas-side flat multi-hole pipe 45a (see FIG. 24). Since the description has been given in the first embodiment, the description of the gas-side flat multi-hole tube 45a will be omitted. As shown in FIG. 22, the third pass P13 includes, for example, a total of 19 flat multi-hole tubes 45 (gas-side flat multi-hole tubes 45a).

(1-2-4) 4th pass The 4th pass P14 has many points in common with the 4th pass P4 of the first embodiment. The fourth pass P14 is mainly composed of a flat multi-hole pipe 45 that communicates the first header space Sb1 in the back row, the first header space Sb1 in the back row, and the second header space Sb2 in the back row, and the second header space Sb2 in the back row. It is formed.

During the cooling operation, the refrigerant flows from the second header space Sb2 in the back row toward the first header space Sb1 in the back row in the fourth pass P14.

The flow of the refrigerant in the fourth pass P14 during the heating operation is the same as the flow of the refrigerant in the fourth pass P4 of the first embodiment. The difference is that the refrigerant that has passed through the gas-side flat multi-hole pipe 45a of the fourth pass P14 and merged in the second header space Sb2 in the back row passes through the second connection pipe 172 and the third space A13 in the front row and passes through the first pass. It is guided to a plurality of liquid-side flat multi-hole pipes 45b of P11.

The flat multi-hole pipe 45 of the fourth pass P14 is a gas-side flat multi-hole pipe 45a (see FIG. 25). As shown in FIG. 22, the fourth pass P14 includes, for example, a total of 19 flat multi-hole tubes 45 (gas-side flat multi-hole tubes 45a).

In the indoor heat exchanger 125 of the present embodiment, the number (0) of the gas-side flat multi-hole tubes 45a included in the front row heat exchange section (front row heat exchange section 150) on the wind side in the air flow direction dr3 is increased. It has a configuration that is smaller than the number (19) of the gas-side flat multi-hole tubes 45a included in the heat exchange section (rear row heat exchange section 160) in the last row on the leeward side. Here, the number of gas-side flat multi-hole pipes 45a included in the heat exchange portion in the front row on the wind side in the air flow direction dr3 is 0, and the gas side is in the heat exchange portion in the last row on the leeward side. Even when the flat multi-hole pipe 45a is included, the number of gas-side flat multi-hole pipes 45a included in the heat exchange portion in the front row on the leeward side is the number of gas-side flat multi-hole pipes included in the heat exchange portion in the last row on the leeward side. It shall be included in the configuration that the number is smaller than the number of hole tubes 45a.

Further, the indoor heat exchanger 125 of the present embodiment has a configuration in which a plurality of heat exchange units (middle row heat exchange unit 180 and back row heat exchange unit 160) include a gas-side flat multi-hole tube 45a.

Further, in the indoor heat exchanger 125 of the present embodiment, the total number of gas-side flat multi-hole tubes 45a is 38 (rear row heat exchange section 160: 19, middle row heat exchange section 180: 19), and the liquid side flat multi-hole tube 45a. It has a configuration that the total number of hole tubes 45b is larger than 19 (front row heat exchange section 150).

Further, the indoor heat exchanger 125 of the present embodiment has a configuration in which only the front row heat exchange unit 150 (upper windward) in the front row includes the liquid side flat multi-hole tube 45b.

Further, the indoor heat exchanger 125 of the present embodiment has a configuration in which the gas-side flat multi-hole pipe 45a is provided with a gas refrigerant inlet / outlet 45aa on the first header 186,166 side.

(1-3) Refrigerant flow in the indoor heat exchanger (1-3-1) During cooling operation The description of the refrigerant flow during cooling operation will be omitted here. During the cooling operation, the refrigerant flows in the paths P11 to P14 of the indoor heat exchanger 125 in the direction opposite to that during the heating operation.

(1-3-2) During heating operation In the indoor heat exchanger 125 during heating operation, the overheated gas refrigerant flows in from the gas side inlet / outlet GH and is cooled by the heat exchange units 150, 160, 180, and is in an overcooled state. The liquid refrigerant of the above flows out from the liquid side inlet / outlet LH.

FIG. 26 is a schematic diagram schematically showing the flow of the refrigerant in the front row heat exchange unit 150 during the heating operation. FIG. 27 is a schematic diagram schematically showing the flow of the refrigerant in the middle row heat exchange unit 180 during the heating operation. FIG. 28 is a schematic diagram schematically showing the flow of the refrigerant in the back row heat exchange unit 160 during the heating operation. In FIGS. 26 to 28, the broken line arrow indicates the flow direction of the refrigerant.

During the heating operation, the superheated gas refrigerant flowing through the first gas refrigerant pipe 21a flows into the middle row first header space Sc1 of the middle row first header 186 via the first gas side inlet / outlet GH1. The gas refrigerant flowing into the first header space Sc1 in the middle row passes through the flat pipe flow path 451 of the gas-side flat multi-hole pipe 45a of the third pass P13 while exchanging heat with the indoor air flow AF and being cooled. The refrigerant that has been cooled in the gas-side flat multi-hole pipe 45a of the third pass P13 and has become a two-phase state in the middle of the gas-side flat multi-hole pipe 45a flows into the second header space Sc2 in the middle row. The refrigerant that has flowed into the second header space Sc2 in the middle row flows into the fourth space A14 in the front row via the first connection pipe 171. The refrigerant flowing into the fourth space A14 in the front row exchanges heat with the indoor air flow AF and passes through the flat pipe flow path 451 of the liquid-side flat multi-hole pipe 45b of the second pass P12 while being in an overcooled state, and passes through the second space in the front row. It flows out to the second liquid refrigerant pipe 22b via A12 and the first liquid side inlet / outlet LH1.

Further, during the heating operation, the overheated gas refrigerant flowing through the second gas refrigerant pipe 21b flows into the rear row first header space Sb1 via the second gas side inlet / outlet GH2. The gas refrigerant flowing into the first header space Sb1 in the back row passes through the flat pipe flow path 451 of the gas-side flat multi-hole pipe 45a of the fourth pass P14 while exchanging heat with the indoor air flow AF and being cooled. The refrigerant cooled in the gas-side flat multi-hole pipe 45a of the fourth pass P14 and is in a two-phase state in the middle of the gas-side flat multi-hole pipe 45a flows into the second header space Sb2 in the rear row. The refrigerant that has flowed into the second header space Sb2 in the back row flows into the third space A13 in the front row of the second header 57 in the front row via the second connection pipe 172. The refrigerant flowing into the third space A13 in the front row exchanges heat with the indoor air flow AF and passes through the flat pipe flow path 451 of the liquid-side flat multi-hole pipe 45b of the first pass P11 while being in an overcooled state, and passes through the first space in the front row. It flows out to the first liquid refrigerant pipe 22a via A11 and the second liquid side inlet / outlet LH2.

Inside the front row second header 157, there is a space (front row fourth space A14) into which the refrigerant flowing out of the gas side flat multi-hole tube 45a of the middle row heat exchange section 180 flows in, and a gas side flat multi hole of the back row heat exchange section 160. The space (front row third space A13) into which the refrigerant flowing out of the hole pipe 45a flows is isolated. In other words, inside the front row second header 157, a horizontal partition plate 571 that separates the refrigerant flowing out from the gas-side flat multi-hole tube 45a by the heat exchange unit is arranged.

During the heating operation (particularly when the operation is in a steady state), in the indoor heat exchanger 125, the flat pipe flow path 451 in the third pass P13 (particularly, the middle row first header in the third pass P13). Region in which the overheated refrigerant flows in the flat pipe flow path 451 of the gas side flat multi-hole pipe 45a on the 186 side (for example, the flat pipe flow path 451 included in the third pass P13 of the first heat exchange surface 181 in the middle row). (Overheated region SH11) is formed. The region other than the superheated region SH11 of the flat tube flow path 451 of the third pass P13 is mainly a two-phase region through which the two-phase refrigerant flows. Further, the flat pipe flow path 451 in the fourth pass P14 (in particular, the flat pipe flow path 451 on the rear row first header 166 side in the fourth pass P14 (for example, in the fourth pass P14 of the rear row first heat exchange surface 161). A region (superheated region SH12) through which the superheated refrigerant flows is formed in the included flat pipe flow path 451). The region other than the superheated region SH12 of the flat pipe flow path 451 of the fourth pass P14 is mainly two-phase. The superheated region SH11 and the superheated region SH12 are two-phase regions through which the refrigerant flows. The superheated region SH11 and the superheated region SH12 are examples of gas regions in which the gas refrigerant flows, which are formed in the vicinity of the gas refrigerant inlet / outlet port 45aa of the gas-side flat multi-hole pipe 45a.

In the indoor heat exchanger 125 of the present embodiment, as described above, the gas-side flat multi-hole tube 45a is provided with a gas refrigerant inlet / outlet 45aa on the first header 186,166 side. Therefore, as shown in FIGS. 27 and 28, the superheated region SH11 of the middle row heat exchange unit 180 and the superheated region SH12 of the back row heat exchange unit 160 are on the same end side (first) of the flat multi-hole tube 45. It is arranged on the header 186,166 side). That is, the superheated region SH11 of the middle row heat exchange unit 180 and the superheated region SH12 of the rear row heat exchange unit 160 are arranged so as to overlap each other in the air flow direction dr3. Further, the refrigerant flowing through the superheated region SH11 of the middle row heat exchange unit 180 and the refrigerant flowing through the superheated region SH12 of the rear row heat exchange unit 160 have the same flow direction (that is, parallel flow).

In the indoor heat exchanger 125 of the present embodiment, the middle row heat exchange unit 180 is a gas side flat multi-hole pipe 45a (first) in which a gas refrigerant inlet / outlet 45aa is provided on the first end side (middle row first header 186 side). 1 Gas side flat multi-hole tube) is included. Further, the rear row heat exchange unit 160 includes a gas side flat multi-hole tube 45a (first gas-side flat multi-hole tube) provided with a gas refrigerant inlet / outlet 45aa on the first end side (rear row first header 166 side). In the indoor heat exchanger 125 of the present embodiment, the gas-side flat multi-hole tube 45a is arranged in the middle row heat exchange unit 180 and the back row heat exchange unit 160 as a whole in the height direction. Therefore, the first gas in the first direction (flat tube stacking direction dr2) is on the leeward side in the air flow direction of the gas side flat multi-hole tube 45a (first gas side flat multi-hole tube) of the middle row heat exchange portion 180. Gas refrigerant inlet / outlet on the first end side (rear row first header 166 side) at the same position as the side flat multi-hole pipe (that is, at the same height position as the first gas side flat multi-hole pipe of the middle row heat exchange unit 180). Only the gas-side flat multi-hole tube 45a of the back row heat exchange portion 160 provided with 45aa is arranged. Further, the heat exchange section is not arranged on the leeward side of the gas side flat multi-hole tube 45a (first gas side flat multi-hole tube) of the back row heat exchange section 160 in the air flow direction.

Further, in the indoor heat exchanger 125 of the present embodiment, the heat exchange efficiency between the refrigerant and the indoor air flow AF in the middle row heat exchange unit 180 on the wind side of the rear row heat exchange unit 160 is the middle row heat exchange unit 180. It is higher than the heat exchange efficiency between the refrigerant and the indoor air flow AF in the rear row heat exchange unit 160 on the leeward side that has passed through. Therefore, the length of the superheated region SH11 in the flat tube extending direction dr1 is smaller than the length of the superheated region SH12 (see FIGS. 27 and 28). Therefore, the area of the superheated region SH11 is smaller than the area of the superheated region SH12 (see FIGS. 27 and 28). In other words, the superheated region SH11 is included in the superheated region SH12 when viewed along the air flow direction dr3.

In other words, the flat multi-hole pipe 45 is not provided with the two-phase / liquid region through which the two-phase refrigerant or the liquid-phase refrigerant flows on the leeward side of the superheated region SH11 in the air flow direction dr3. Therefore, the indoor air flow AF that has exchanged heat with the high-temperature gas refrigerant can suppress the deterioration of the condensation performance of the indoor heat exchanger 125 due to the heat exchange with the low-temperature gas refrigerant.

Further, during the heating operation (particularly when the operation is in a steady state), in the indoor heat exchanger 125, the flat tube flow path 451 in the first pass P11 (particularly, the front row in the first pass P11). In the flat tube flow path 451 on the first header 156 side (for example, the flat tube flow path 451 included in the first pass P11 of the front row first heat exchange surface 151), a region (overcooling region) through which the overcooled refrigerant flows. SC11) is formed. The region other than the overcooling region SC11 of the flat tube flow path 451 in the first pass P11 is mainly a two-phase region through which the two-phase refrigerant flows. Further, in the indoor heat exchanger 125, the flat tube flow path 451 in the second pass P12 (particularly, the flat tube flow path 451 on the front row first header 156 side in the second pass P12 (for example, the front row first heat exchange). In the flat tube flow path 451)) included in the second pass P12 of the surface 151, a region (supercooled region SC12) through which the supercooled refrigerant flows is formed. The region other than the supercooled region SC12 of the flat pipe flow path 451 in the second pass P12 is mainly a two-phase region through which the two-phase refrigerant flows. In the present embodiment, the liquid-side flat multi-hole pipe 45b is a flat multi-hole pipe (first liquid-side flat multi-hole pipe) provided with a liquid refrigerant inlet / outlet 45ba on the first end side (front row first header 156 side). ).

Here, since the front row heat exchange section 150 provided with the liquid-side flat multi-hole tube 45b is the heat exchange section located on the most windy side in the air flow direction dr3, the air flow direction of the liquid-side flat multi-hole tube 45b. The heat exchange unit is not arranged on the wind side of dr3. In other words, the two-phase / gas region through which the flat multi-hole pipe 45 flows is not arranged on the wind side of the supercooled regions SC11 and SC12 in the air flow direction dr3. Therefore, here, it is possible to suppress that the refrigerant once cooled to a predetermined supercooling degree is heated by the air warmed by the two-phase refrigerant or the gas refrigerant on the windward side, and it is possible to suppress the deterioration of performance. Further, when viewed from the air side, it is possible to suppress that the air warmed by the two-phase refrigerant or the gas refrigerant is cooled by the refrigerant supercooled on the leeward side during the heating operation, and it is possible to suppress the deterioration of the heating performance.

(2) Features The indoor heat exchanger 125 according to the second embodiment also has the same features as (5-1) to (5-9) of the indoor heat exchanger 25 according to the first embodiment. In addition, the indoor heat exchanger 125 has the following features.

(2-1)
The indoor heat exchanger 125 has at least three rows (here, particularly three rows) of heat exchange units 150, 160, 180. Only the front row heat exchange section, that is, the front row heat exchange section 150 includes the liquid side flat multi-hole tube 45b.

Here, when the indoor heat exchanger 125 is used as a condenser, the heating region is concentrated on the back row side, so that it is possible to improve the performance (higher blowing temperature).

(3) Modification example The above embodiment can be appropriately modified as shown in the following modification example. In addition, each modification may be applied in combination with another modification as long as there is no contradiction.

Further, a part or all of the configuration of the first embodiment and the configuration of the modification of the first embodiment can be applied to the modification of the present embodiment as long as there is no contradiction.

On the contrary, a part or all of the configuration of the second embodiment and the configuration of the modified example of the second embodiment may be applied to the modified embodiment of the first embodiment as long as there is no contradiction.

(3-1) Modification 2A
In the above embodiment, the indoor heat exchanger 125 has three rows of heat exchange units, but is not limited thereto. The heat exchanger may have four or more rows of heat exchangers. Even when the heat exchange section has four or more rows, the number of gas-side flat multi-hole pipes 45a included in the heat exchange section in the front row is the number of gas-side flat multi-hole tubes included in the heat exchange section in the last row. It is preferably less than the number of 45a.

(3-2) Modification 2B
In the above embodiment, the front row heat exchange section of the indoor heat exchanger 125, that is, the front row heat exchange section 150 has only the liquid side flat multi-hole tube 45b, and the gas side flat multi-hole tube 45a. Not.

However, the present invention is not limited to this, and the indoor heat exchanger may be the indoor heat exchanger 125a with a pass as shown in FIG. 29. In the indoor heat exchanger 125a, a gas side inlet / outlet GH is provided in the front row first space A11, and a gas refrigerant pipe 21 is connected to the gas side inlet / outlet GH.

As a result, during the heating operation, the flat multi-hole pipe 45 of the first pass P11 in the above-described embodiment functions as the gas-side flat multi-hole pipe 45a.

Then, during the heating operation, the refrigerant that has passed through the gas-side flat multi-hole pipe 45a of the first pass P11, the third pass P13, and the fourth pass P14 passes through the folded pipe 58 and the connecting pipes 171 and 172 in the front row fourth. Guided to space A14. It is preferable that the fourth space A14 in the front row is divided into three in the flat tube stacking direction dr2 by the horizontal partition plate 571 (see FIG. 29). Then, it is preferable that the refrigerant that has passed through the gas-side flat multi-hole tube 45a of the heat exchange portions in different rows is guided to each of the three sections formed by the horizontal partition plate 571. The refrigerant that has flowed into the front row fourth space A14 is guided into the front row second space A12 in the second pass P12, merges in the front row second space A12 (in the front row first header 156), and flows into the liquid side inlet / outlet LH. Flows out to the liquid refrigerant pipe 22. As a result, during the heating operation, the superheated areas SH21, SH22 and SH23 and the supercooled area SC21 are formed as shown in FIG. The regions not marked with symbols other than the superheated regions SH21, SH22 and SH23, and the supercooled region SC21 are mainly two-phase refrigerant regions in which the two-phase refrigerant flows in the flat multi-hole pipe 45.

As in the above-described embodiment, the superheated regions SH21, SH22, and SH23 are arranged so as to overlap each other in the air flow direction dr3. Further, for the same reason as described above, the areas of the superheated areas SH21, SH22, and SH23 have a relationship of (area of SH23)> (area of SH22)> (area of SH21). The effects obtained by such a configuration are as described above.

(3-3) Modification 2C
In the above embodiment, only the heat exchange portion in the front row of the indoor heat exchanger 125 has the liquid side flat multi-hole tube 45b, but the present invention is not limited thereto. For example, as in the indoor heat exchanger 125b of FIG. 31, the middle row heat exchange unit 180 may also have a liquid-side flat multi-hole tube 45b.

In the indoor heat exchanger 125b, (the number of gas-side flat multi-hole tubes 45a in the front row heat exchange section 150) ≤ (the number of gas-side flat multi-hole tubes 45a in the middle row heat exchange section 180) ≤ (the number of back row heat exchanges). The relationship of (the number of gas-side flat multi-hole tubes 45a) of the portion 160 is established, and (the number of gas-side flat multi-hole tubes 45a of the front row heat exchange section 150 (in the front row)) <((last row) back row). It is preferable that the relationship (the number of the gas-side flat multi-hole tubes 45a) of the heat exchange unit 160 is established. Particularly preferably, in the indoor heat exchanger 125b, (the number of gas-side flat multi-hole pipes 45a in the front row heat exchange unit 150) <(the number of gas-side flat multi-hole pipes 45a in the middle row heat exchange unit 180) <(rear row). The relationship of the number of gas-side flat multi-hole pipes 45a of the heat exchange unit 160) is established. Even when having four or more rows of heat exchange portions, it is preferable that such a quantitative relationship of the gas-side flat multi-hole tube 45a is established.

Further, in the indoor heat exchanger 125b, the relationship (the number of liquid-side flat multi-hole pipes 45b of the front row heat exchange unit 150) ≥ (the number of liquid-side flat multi-hole pipes 45b of the middle row heat exchange unit 180) is established. Is preferable. Particularly preferably, in the indoor heat exchanger 125b, (the number of liquid-side flat multi-hole tubes 45b of the front row heat exchange unit 150 (on the leeward side))> (the number of liquid-side flat multi-hole tubes 45b of the middle row heat exchange unit 180 (on the leeward side))> The relationship (number of multi-hole tubes 45b) holds. In this modification, the relationship (number of liquid-side flat multi-hole tubes 45b of the front row heat exchange section 150)> (number of liquid-side flat multi-hole tubes 45b of the middle row heat exchange section 180) is established.

The flow of the refrigerant in the indoor heat exchanger 125b during the heating operation will be outlined. In addition, in order to avoid the explanation becoming redundant, the description about the specific mode of path taking is omitted here.

In the indoor heat exchanger 125a, the gas refrigerant inlet / outlet 45aa of the gas-side flat multi-hole pipe 45a are all provided on the first header 156, 166, 186 side. Further, the liquid refrigerant inlet / outlet 45ba of the liquid side flat multi-hole tube 45b is provided on the first header 156, 186 side.

The refrigerant that has flowed through the gas-side flat multi-hole tube 45a of the back-row heat exchange section 160 flows into the rear-row second header 167 and joins them, and the liquid-side flat multi-hole tube of the middle-row heat exchange section 180 and the front-row heat exchange section 150. It separately flows into the end openings on the second header 187 and 157 sides of 45b. The refrigerant that has flowed through the gas-side flat multi-hole tube 45a of the middle-row heat exchange section 180 flows into the middle-row second header 187 and joins them, and the liquid-side flat multi-hole tube of the middle-row heat exchange section 180 and the front-row heat exchange section 150. It separately flows into the end openings on the second header 187 and 157 sides of the hole tube 45b. The refrigerant that has flowed through the gas-side flat multi-hole pipe 45a of the front row heat exchange section 150 flows into the front row second header 157 and joins them, and joins the second header 157 of each liquid-side flat multi-hole tube 45b of the front row heat exchange section 150. It splits into the side end opening and flows in. The refrigerant that has passed through the flat pipe flow path 451 of the liquid side flat multi-hole pipe 45b of the middle row heat exchange unit 180 and the front row heat exchange unit 150 flows out from the liquid refrigerant inlet / outlet 45ba and finally flows out from the liquid refrigerant pipe 22. ..

As a result of the flow of the refrigerant in this way, the superheated regions SH31, SH32 and SH33 and the supercooled regions SC31 and SC32 are formed in the indoor heat exchanger 125b during the heating operation as shown in FIG. The regions not marked with symbols other than the superheated regions SH21, SH22 and SH23, and the supercooled region SC21 are mainly two-phase refrigerant regions in which the two-phase refrigerant flows in the flat multi-hole pipe 45.

As described above, the superheated regions SH31, SH32, and SH33 are preferably arranged so as to overlap each other in the air flow direction dr3. Further, for the same reason as described above, it is preferable that the areas of the superheated areas SH31, SH32, and SH33 have a relationship of (area of SH33)> (area of SH32)> (area of SH31). The effects obtained by such a configuration are as described above.

In the indoor heat exchanger 125b, the number of liquid-side flat multi-hole pipes 45b included in the leeward-side middle row heat exchange unit 180 is the number of liquid-side flat multi-hole pipes 45b included in the leeward-up front row heat exchange unit 150. Less than the number of. Therefore, the length of the supercooled region SC32 in the flat tube stacking direction dr2 is smaller than the length of the supercooled region SC31 (see FIG. 31). In other words, the liquid side flat multi-hole tube 45b of the middle row heat exchange unit 180, which is provided with the liquid refrigerant inlet / outlet 45ba on the middle row first header 186 side, is on the wind side in the air flow direction dr3 of the liquid side flat multi-hole tube 45b. Only the liquid-side flat multi-hole tube 45b of the front row heat exchange unit 150 having the liquid refrigerant inlet / outlet 45ba provided on the middle row first header 186 side is arranged at the same position in the hole tube 45b and the flat tube stacking direction dr2. Will be. Further, the heat exchange efficiency between the refrigerant and the indoor air flow AF in the front row heat exchange section 150 on the wind side is the heat exchange efficiency between the refrigerant and the indoor air flow AF in the middle row heat exchange section 180 on the leeward side that has passed through the front row heat exchange section 150. Higher than heat exchange efficiency with. Therefore, the length of the supercooled region SC32 in the flat tube extending direction dr1 is smaller than the length of the supercooled region SC31 (see FIG. 31). Therefore, the areas of the overcooled areas SC31 and SC32 have a relationship of (area of SC31)> (area of SC32), and when viewed in the air flow direction dr3, the overcooled area SC32 becomes the overcooled area SC31. Be included.

With this configuration, when the indoor heat exchanger 125b is used as a condenser, it is possible to prevent the once cooled refrigerant from being heated by the air warmed on the wind side, and suppress performance deterioration. can.

Although the embodiments of the present disclosure have been described above, it will be understood that various modifications of the embodiments and details are possible without departing from the spirit and scope of the present disclosure described in the claims. ..

The present disclosure is widely applicable to heat exchangers and refrigeration equipment equipped with heat exchangers.

25, 25a, 25b Indoor heat exchanger (heat exchanger)
45 Flat multi-hole pipe 45a Gas side flat multi-hole pipe (1st gas side flat multi-hole pipe)
45aa Gas refrigerant inlet / outlet 45b Liquid side flat multi-hole tube 45ba Liquid refrigerant inlet / outlet 50 Front row heat exchange section (front row heat exchange section)
57 Front row second header (confluence, header pipe)
60 Back row heat exchange section (last row heat exchange section)
67 Back row 2nd header (confluence)
100 Air conditioner (refrigerator)
125, 125a, 125b Indoor heat exchanger (heat exchanger)
150 Front row heat exchange section (front row heat exchange section)
157 Front row 2nd header (confluence, header pipe)
160 Back row heat exchange section (last row heat exchange section)
167 Back row 2nd header (confluence)
180 Middle row heat exchange section (heat exchange section)
187 Middle row 2nd header (confluence)
571 Horizontal partition plate (partition plate)
SH3, SH4 Superheat region (gas region)
SH11, SH12 Superheat region (gas region)
SH21, SH22, SH23 Superheat region (gas region)
SH31, SH32, SH33 Superheat region (gas region)
dr2 flat tube stacking direction (first direction)
dr3 air flow direction

Japanese Unexamined Patent Publication No. 2016-388192

Claims (12)

Heat exchange units (50, 60, 150,) in which a plurality of flat multi-hole pipes (45) extending from the first end side toward the second end side and flowing through the inside are arranged side by side in the first direction (dr2). 160, 180), a heat exchanger having a plurality of rows, in which the heat exchange portions of the plurality of rows are arranged so as to overlap in the air flow direction (dr3).
The flat multi-hole pipe is the inlet of the most upstream refrigerant of the flat multi-hole pipe in the refrigerant flow direction in the heat exchanger, or the most downstream of the flat multi-hole pipe in the refrigerant flow direction in the heat exchanger. Includes a gas-side flat multi-hole pipe (45a) provided at one end with a gas refrigerant inlet / outlet (45aa) serving as an outlet for the refrigerant.
The heat exchange section in at least two rows includes the gas-side flat multi-hole tube.
The front row of the heat exchanging portion of the windward side included in the (50, 150), the number of gas-side flat multi-hole tubes (45a) are included in the heat exchanging portion of the last column of the leeward side (60, 160) Less than the number of flat multi-hole tubes on the gas side,
Heat exchanger (25 , 25a, 125, 125a, 125b). Unlike the gas-side flat multi-hole tube, the flat multi-hole tube further includes a liquid-side flat multi-hole tube (45b) provided with a liquid refrigerant inlet / outlet (45ba) at one end.
The heat exchanger according to claim 1. The total number of gas-side flat multi-hole tubes is larger than the total number of liquid-side flat multi-hole tubes.
The heat exchanger according to claim 2. Each of the gas-side flat multi-hole pipes is provided with the gas refrigerant inlet / outlet on the first end side.
The heat exchanger according to any one of claims 1 to 3. Further provided with a merging portion (57,67,157,167,187) for merging the refrigerants flowing out from the plurality of gas-side flat multi-hole pipes and guiding them to the liquid-side flat multi-hole pipe.
The heat exchanger according to claim 2 or 3. A header pipe (57,157) for guiding the refrigerant flowing out of the gas-side flat multi-hole pipe to the plurality of liquid-side flat multi-hole pipes is further provided.
Inside the header pipe, a partition plate (571) for separating the refrigerant flowing out of the gas-side flat multi-hole pipe for each heat exchange unit is arranged.
The heat exchanger according to claim 2 or 3. Refrigerant flows in the same direction to all the flat multi-hole pipes.
The heat exchanger (25a) according to any one of claims 1 to 6. It has three rows of heat exchange units.
The heat exchanger (125, 125a, 125b) according to any one of claims 1 to 7. It has at least three rows of the heat exchanges and has
Only the heat exchange part in the front row includes the liquid side flat multi-hole tube,
The heat exchanger (125) according to claim 2. The gas-side flat multi-hole pipe includes a first gas-side flat multi-hole pipe (45a) provided with the gas refrigerant inlet / outlet on the first end side.
The heat exchange portion is not arranged on the leeward side of the first gas side flat multi-hole tube in the air flow direction.
Or,
On the leeward side of the first gas side flat multi-hole pipe in the air flow direction, the gas refrigerant inlet / outlet is located at the same position as the first gas-side flat multi-hole pipe in the first direction, and on the first end side. Only the provided gas-side flat multi-hole tube is arranged.
The heat exchanger according to any one of claims 1 to 9. In the gas-side flat multi-hole tube, gas regions (SH3, SH4, SH11, SH12, SH21, SH22, SH23, SH31, SH32, SH33) through which the gas refrigerant flows are formed in the vicinity of the gas refrigerant inlet / outlet.
A two-phase / liquid region through which a two-phase refrigerant or a liquid-phase refrigerant flows through the flat multi-hole tube is not arranged on the leeward side of the gas region in the air flow direction.
The heat exchanger according to any one of claims 1 1 0. The heat exchanger according to any one of claims 1 to 11 is installed.
Refrigerating device (100).

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