JP2016084993A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger which facilitates defrosting.SOLUTION: An outdoor heat exchanger 13 includes: a first header collection tube 45; a second header collection tube 50; a plurality of heat exchange parts including a plurality of heat transfer pipes 31; and a connection pipeline 55 for supplying a high pressure gas refrigerant. Each space in second header upper spaces 501 communicates with one of second header lower spaces 502. The connection pipeline 55 includes: a twelfth upper heat exchange part X12 which includes the heat transfer pipe 31 for communicating with the space in the second header upper space 501 which communicates with an uppermost stage space SP13 in the second header lower space 502; and a first branch pipe BP1 connected to the first header collection tube 45 at the same height position. The connection pipeline 55 includes: a first upper heat exchange part X1 including the heat transfer pipe 31 for communicating with the space in the second header upper space 501 which communicates with an uppermost stage space SP24 in the second header lower space 502; and a second branch pipe BP2 connected to the first header collection tube 45 at the same height position.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a heat exchanger.

  2. Description of the Related Art Conventionally, there is a heat exchanger that has a heat exchanging unit including a plurality of header collecting tubes and a plurality of heat transfer tubes and functions as an evaporator during heating operation. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2013-155961) discloses a heat exchanger that functions as an evaporator during heating operation, and includes a first header collecting pipe and a second header collecting pipe, and a first header. A heat exchanger is disclosed in which a plurality of heat exchange parts including heat transfer tubes connected to the collecting pipe and the second header collecting pipe are arranged in the vertical direction. In the heat exchanger disclosed in Patent Document 1, any one of the upper heat exchange units is in communication with any one of the lower heat exchange units via a space in the second header collecting pipe.

  Moreover, in patent document 1, in order to suppress the performance fall by the frost adhering at the time of heating operation, the defrost operation which supplies hot gas from a connection piping to a 1st header collecting pipe is performed according to the condition.

  In the heat exchanger as described above, frost tends to adhere to the lower heat exchange section during heating operation. Therefore, during defrost operation, it is possible to supply hot gas at an appropriate flow rate to the lower heat exchange section. It is preferable from the viewpoint of shortening.

  However, in Patent Document 1, the height position of the outlet of the connection pipe connected to the first header collecting pipe is away from any upper heat exchange section. In the section, the variation in the flow rate of the hot gas flowing through the heat transfer tube increases. In such a case, in each lower heat exchange section, the variation in the flow rate of the hot gas flowing through the heat transfer tube becomes large, and it is difficult to shorten the time required for defrosting at a location where the flow rate of the hot gas is small.

  Therefore, an object of the present invention is to provide a heat exchanger that promotes defrosting.

  A heat exchanger according to a first aspect of the present invention includes a first header collecting pipe, a second header collecting pipe, a plurality of heat exchange units, and a connection pipe. The first header collecting pipe extends in the vertical direction. The interior of the first header collecting pipe is partitioned into a first header upper space and a first header lower space. The first header lower space is located below the first header upper space. The second header collecting pipe extends in the vertical direction. The inside of the second header collecting pipe is partitioned into a second header upper space and a second header lower space. The second header lower space is located below the second header upper space. The plurality of heat exchange units have a plurality of heat transfer tubes. The heat transfer tube extends along the horizontal direction. The plurality of heat exchange units are arranged in the vertical direction. The connection pipe communicates with the first header upper space. The connection pipe supplies a high-pressure gas refrigerant. The heat transfer tube communicates with the first header upper space and the second header upper space, or communicates with the first header lower space and the second header lower space. A plurality of spaces arranged in the vertical direction are formed inside the second header upper space. A plurality of spaces arranged in the vertical direction are formed inside the second header lower space. Each space in the second header upper space communicates with one of the spaces in the second header lower space. The connection pipe includes a first branch pipe and a second branch pipe. The first branch pipe has a first header assembly at the same height as the heat exchange part including the heat transfer pipe communicating with the space in the second header upper space communicating with the uppermost space in the second header lower space. Connected to the tube. The second branch pipe has a first header assembly at the same height as the heat exchange part including the heat transfer pipe communicating with the space in the second header upper space communicating with the lowermost space in the second header lower space. Connected to the tube.

  In the heat exchanger according to the first aspect of the present invention, the first branch pipe of the connection pipe for supplying the high-pressure gas refrigerant is in the second header upper space communicating with the uppermost space in the second header lower space. The heat exchange part including the heat transfer pipe communicating with the space is connected to the first header collecting pipe at the same height position. In addition, the second branch pipe of the connection pipe has the same height position as the heat exchange section including the heat transfer pipe communicating with the space in the second header upper space communicating with the lowermost space in the second header lower space. To be connected to the first header collecting pipe. Thereby, at the time of defrost operation, in the first header collecting pipe, the heat transfer pipe communicating with the space in the second header upper space communicating with the uppermost space in the second header lower space, and the second header lower space A high-pressure gas refrigerant is supplied at a position close to the inlet of the heat transfer pipe communicating with the space in the second header upper space communicating with the lowermost space inside. That is, the gas refrigerant is supplied to a position close to the inlet of the refrigerant flow path leading to the uppermost and lowermost spaces in the second header lower space. As a result, the gas refrigerant is stably supplied to the uppermost and lowermost spaces in the second header lower space. Therefore, the time required for defrosting is shortened in the lower heat exchange section where frost easily adheres. Therefore, defrosting is promoted.

  The heat exchanger which concerns on the 2nd viewpoint of this invention is a heat exchanger which concerns on a 1st viewpoint, Comprising: A 1st branch pipe is a heat | fever containing the heat exchanger tube connected with the lowest space in the 2nd header upper space. The exchange part is connected to the first header collecting pipe at the same height position. The second branch pipe is connected to the first header collecting pipe at the same height position as the heat exchange part including the heat transfer pipe communicating with the uppermost space in the second header upper space. The connection pipe is connected to the first header collecting pipe at a height position between the first branch pipe and the second branch pipe. Thereby, at the time of defrost operation, the high-pressure gas refrigerant supplied to the first header upper space is stably supplied to each heat transfer tube communicating with the first header upper space, and the heat transfer tube is installed in each upper heat exchange section. Variation in the flow rate of the flowing gas refrigerant is suppressed. That is, the gas refrigerant is stably supplied to the refrigerant flow paths that communicate with the spaces in the second header upper space and the second header lower space. As a result, the gas refrigerant is stably supplied to each space in the second header upper space and the second header lower space, and variations in the flow rate of the gas refrigerant flowing through the heat transfer tubes in each lower heat exchange section are suppressed. . Therefore, the time required for defrosting is further shortened in the lower heat exchange section where frost easily adheres.

  The heat exchanger which concerns on the 3rd viewpoint of this invention is a heat exchanger which concerns on a 1st viewpoint or a 2nd viewpoint, Comprising: A 2nd branch pipe is gas rather than the position where a 1st branch pipe branches in connection piping. Branches at a position upstream of the refrigerant flow path. This increases the flow rate of the high-pressure gas refrigerant flowing into the second branch pipe during the defrost operation, so that the gas refrigerant is more stably supplied to the refrigerant flow path leading to the lowermost space in the lower space of the second header. Supplied. As a result, the gas refrigerant is more stably supplied to the lowermost space in the second header lower space. Therefore, the time required for defrosting is further shortened particularly in the lowermost heat exchange section where frost is likely to adhere.

  The heat exchanger which concerns on the 4th viewpoint of this invention is a heat exchanger which concerns on either of the 1st viewpoint to the 3rd viewpoint, Comprising: The front-end | tip part is notched in the 1st branch pipe and the 2nd branch pipe Yes. The tip is the part that is inserted into the connection pipe. Thereby, at the time of defrost operation, the high-pressure gas refrigerant flowing through the connection pipe flows into the first branch pipe and the second branch pipe through the notched portion. As a result, the gas refrigerant can easily flow into the first branch pipe and the second branch pipe as compared with the case where the tip is not cut out. Therefore, the high-pressure gas refrigerant is more stably supplied to the refrigerant flow path leading to the uppermost and lowermost spaces of the second header lower space.

  A heat exchanger according to a fifth aspect of the present invention is the heat exchanger according to any of the first to fourth aspects, wherein the inner diameter of the second branch pipe is larger than the inner diameter of the first branch pipe. As a result, the high-pressure gas refrigerant is more stably supplied to the second branch pipe during the defrost operation. That is, the high-pressure gas refrigerant is supplied more stably in the refrigerant flow path leading to the lowermost space of the second header lower space.

  A heat exchanger according to a sixth aspect of the present invention is a heat exchanger according to any one of the first aspect to the fifth aspect, wherein the first branch pipe and the second branch pipe are inserted into the joining member, Bonded with the bonding member. The joining member is a member joined to the outer peripheral surface of the connection pipe. Thereby, the insertion allowance of the insertion part of the 1st branch pipe and the 2nd branch pipe in connection piping can be controlled. As a result, during defrost operation, the pressure loss of the gas refrigerant flowing in the connection pipe is suppressed, and the gas refrigerant more easily flows into the first branch pipe and the second branch pipe. Therefore, the high-pressure gas refrigerant is more stably supplied to the refrigerant flow paths leading to the respective spaces below the second header.

  The heat exchanger which concerns on the 7th viewpoint of this invention is a heat exchanger which concerns on either of the 1st viewpoint to the 6th viewpoint, Comprising: The insertion allowance in the connection piping of a 2nd branch pipe is the 1st branch pipe It is smaller than the insertion allowance in the connecting pipe. As a result, the high-pressure gas refrigerant is more stably supplied to the second branch pipe during the defrost operation. That is, the high-pressure gas refrigerant is supplied more stably in the refrigerant flow path leading to the lowermost space of the second header lower space.

  The heat exchanger which concerns on the 8th viewpoint of this invention is a heat exchanger which concerns on either of the 1st viewpoint to the 7th viewpoint, Comprising: A connection header is further provided. The connection header extends in the vertical direction. The connection header is formed with a plurality of communication spaces inside. The plurality of communication spaces are arranged in the vertical direction. Each heat transfer tube includes a first heat transfer tube and a second heat transfer tube. One end of the first heat transfer tube is connected to the first header collecting tube, and the other end is connected to the connection header. One end of the second heat transfer tube is connected to the second header collecting tube, and the other end is connected to the connection header. The other end of the first heat transfer tube and the other end of the second heat transfer tube communicate with each other in the communication space. As a result, the first header upper space and the second header upper space, or the first header lower space and the second header lower space via the communication space in the connection header, the first heat transfer tube, and the second heat transfer tube. In the communicating heat exchanger, the time required for defrosting is shortened. That is, when the heat transfer tube includes the first heat transfer tube and the second heat transfer tube, the time required for defrosting is shortened and the defrosting is promoted despite an increase in the area to which frost adheres.

  In the heat exchanger according to the first aspect of the present invention, the gas refrigerant is stably supplied to the uppermost and lowermost spaces in the second header lower space. Therefore, the time required for defrosting is shortened in the lower heat exchange section where frost easily adheres. Therefore, defrosting is promoted.

  In the heat exchanger according to the second aspect of the present invention, the time required for defrosting is further shortened in the lower heat exchange section where frost easily adheres.

  In the heat exchanger according to the third aspect of the present invention, the high-pressure gas refrigerant is more stably supplied to the refrigerant flow path leading to the uppermost and lowermost spaces of the second header lower space.

  In the heat exchanger according to the fourth aspect of the present invention, the high-pressure gas refrigerant is more stably supplied to the refrigerant flow path leading to the uppermost and lowermost spaces of the second header lower space.

  In the heat exchanger according to the fifth aspect of the present invention, the high-pressure gas refrigerant is more stably supplied to the refrigerant flow path leading to the lowermost space of the second header lower space.

  In the heat exchanger according to the sixth aspect of the present invention, the high-pressure gas refrigerant can be more stably supplied to the refrigerant flow paths leading to the respective spaces in the second header lower space.

  In the heat exchanger according to the seventh aspect of the present invention, the gas refrigerant is more stably supplied to the refrigerant flow path leading to the lowermost space in the second header lower space.

  In the heat exchanger according to the eighth aspect of the present invention, when the heat transfer tube includes the first heat transfer tube and the second heat transfer tube communicating with each other via the connection header, the time required for defrosting is shortened and the defrosting is promoted. Is done.

The schematic block diagram of the air conditioning apparatus containing the outdoor heat exchanger which concerns on one Embodiment of this invention. The external appearance perspective view of an outdoor unit. The top view of the outdoor unit of a state which removed the top plate. The external appearance perspective view of an outdoor heat exchanger. The top view of an outdoor heat exchanger. The elements on larger scale of the VI-VI line cross section in FIG. Sectional drawing of the A section of FIG. 5 in a rear view. Sectional drawing of A part of FIG. 5 in front view. Sectional drawing of the B section of FIG. 5 in the left side view. The enlarged view which showed the part below the dashed-two dotted line L12 of FIG. The enlarged view which showed the part above the dashed-two dotted line L12 of FIG. FIG. 9 is an enlarged view showing a portion above the two-dot chain line L5 in FIG. FIG. 9 is an enlarged view showing a portion below the two-dot chain line L5 in FIG. 8 and above the two-dot chain line L11. FIG. 9 is an enlarged view showing a portion below the two-dot chain line L11 of FIG. 8 and above the two-dot chain line L24. The enlarged view of the C section of FIG. FF sectional view taken on the line of FIG. The enlarged view of the D section of FIG. The enlarged view of the E section of FIG.

  Hereinafter, an outdoor heat exchanger 13 according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the outdoor heat exchanger 13 is included in the air conditioner 100. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention, and can be modified as appropriate without departing from the scope of the invention. In the following embodiments, directions such as up, down, left, right, front (front), and back (rear) mean the directions shown in FIGS. 2 to 9 and FIGS. 15 to 18.

(1) Air conditioner 100
FIG. 1 is a schematic configuration diagram of an air conditioning apparatus 100 including an outdoor heat exchanger 13 according to an embodiment of the present invention.

  The air conditioning apparatus 100 is an apparatus that realizes air conditioning in a target space by performing a cooling operation or a heating operation. Specifically, the air conditioning apparatus 100 performs a vapor compression refrigeration cycle. The air conditioner 100 mainly includes an outdoor unit 10 as a heat source side unit and an indoor unit 20 as a use side unit. In the air conditioner 100, the outdoor unit 10 and the indoor unit 20 are connected by a gas refrigerant communication pipe GP and a liquid refrigerant communication pipe LP, thereby forming a refrigerant circuit.

(1-1) Outdoor unit 10
FIG. 2 is an external perspective view of the outdoor unit 10. The outdoor unit 10 is installed outdoors. The outdoor unit 10 has a unit casing 110. The unit casing 110 has a vertically long, substantially rectangular parallelepiped shape, and includes a top plate 111 on the top surface. The unit casing 110 is formed with an intake port (not shown) serving as an inlet for taking an air flow into the unit casing 110 on the back and side surfaces. Further, the unit casing 110 is formed with an exhaust port 112 serving as an outlet for the taken-in air flow. The exhaust port 112 is covered with a front grill 113.

  FIG. 3 is a plan view of the outdoor unit 10 with the top plate 111 removed. In the unit casing 110, a casing partition plate 114 that partitions the internal space of the unit casing 110 to the left and right is disposed. By disposing the casing partition plate 114, the machine casing 10a and the blower chamber 10b are formed in the unit casing 110.

  The outdoor unit 10 mainly includes a refrigerant pipe RP, a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 13, an expansion valve 14, and an outdoor fan 15 that constitute a refrigerant circuit in a unit casing 110. And an outdoor control unit 16. The compressor 11, the four-way switching valve 12, the expansion valve 14, and the outdoor control unit 16 are disposed in the machine room 10a. Moreover, the outdoor heat exchanger 13 and the outdoor fan 15 are arrange | positioned in the air blower chamber 10b.

  The refrigerant flows through the refrigerant pipe RP. Specifically, the refrigerant pipe RP includes a first refrigerant pipe P1, a second refrigerant pipe P2, a third refrigerant pipe P3, a fourth refrigerant pipe P4, a fifth refrigerant pipe P5, and a sixth refrigerant pipe P6.

  The first refrigerant pipe P <b> 1 has one end connected to the gas refrigerant communication pipe GP and the other end connected to the four-way switching valve 12. One end of the second refrigerant pipe P <b> 2 is connected to the four-way switching valve 12, and the other end is connected to the suction port of the compressor 11. The third refrigerant pipe P3 has one end connected to the discharge port of the compressor 11 and the other end connected to the four-way switching valve 12. The fourth refrigerant pipe P4 has one end connected to the four-way switching valve 12 and the other end connected to the outdoor heat exchanger 13. The fifth refrigerant pipe P5 has one end connected to the outdoor heat exchanger 13 and the other end connected to the expansion valve 14. The sixth refrigerant pipe P6 has one end connected to the expansion valve 14 and the other end connected to the liquid refrigerant communication pipe LP.

  The compressor 11 is a mechanism that sucks low-pressure gas refrigerant, compresses it, and discharges it. The compressor 11 has a sealed structure in which a compressor motor 11a is built. In the compressor 11, a rotary type or scroll type compression element (not shown) housed in a casing (not shown) is driven using the compressor motor 11a as a drive source. During operation, the compressor motor 11a is inverter-controlled by the outdoor control unit 16, and the rotational speed is adjusted according to the situation. That is, the compressor 11 has a variable capacity.

  The four-way switching valve 12 is a switching valve for switching the direction in which the refrigerant flows when switching between the cooling operation and the heating operation. The four-way switching valve 12 can be switched in the refrigerant flow path by the outdoor control unit 16. During the cooling operation, the four-way switching valve 12 connects the first refrigerant pipe P1 and the second refrigerant pipe P2 and connects the third refrigerant pipe P3 and the fourth refrigerant pipe P4 (four-way switching valve in FIG. 1). (See 12 solid lines). On the other hand, during the heating operation, the four-way switching valve 12 connects the first refrigerant pipe P1 and the third refrigerant pipe P3 and connects the second refrigerant pipe P2 and the fourth refrigerant pipe P4 (four-way in FIG. 1). (Refer to the broken line of the switching valve 12).

  The outdoor heat exchanger 13 is a heat exchanger that functions as a refrigerant condenser during a cooling operation and functions as a refrigerant evaporator during a heating operation. The liquid side of the outdoor heat exchanger 13 is connected to the expansion valve 14 via the fifth refrigerant pipe P5, and the gas side is connected to the four-way switching valve 12 via the fourth refrigerant pipe P4. During the cooling operation, high-pressure gas refrigerant compressed by the compressor 11 mainly flows into the outdoor heat exchanger 13. During the heating operation, low-pressure liquid refrigerant decompressed by the expansion valve 14 mainly flows into the outdoor heat exchanger 13. The details of the outdoor heat exchanger 13 will be described in “(3) Details of the outdoor heat exchanger 13” described later.

  The expansion valve 14 is an electric valve that depressurizes the flowing high-pressure refrigerant. The opening degree of the expansion valve 14 is appropriately adjusted by the outdoor control unit 16 in accordance with the operation state.

  The outdoor fan 15 flows from the outside into the outdoor unit 10, passes through the outdoor heat exchanger 13, and then flows out of the outdoor unit 10 (see the two-dot chain arrows in FIGS. 3, 4, and 6). ). The outdoor fan 15 is a propeller fan, for example. The outdoor fan 15 is driven using the outdoor fan motor 15a as a drive source. The outdoor fan motor 15a is driven by the outdoor control unit 16 during operation, and the number of rotations is appropriately adjusted.

  The outdoor control unit 16 is a functional unit that controls the operation of the actuator included in the outdoor unit 10. The outdoor control unit 16 includes a microcomputer configured with a CPU, a memory, and the like. The outdoor control unit 16 determines that frost is attached to the outdoor heat exchanger 13 when a temperature sensor (not shown) mounted on the outdoor heat exchanger 13 falls below a predetermined threshold during the heating operation. Then, a command to execute the defrost operation is transmitted to the indoor control unit 23 (described later).

(1-2) Indoor unit 20
The indoor unit 20 is installed indoors. The indoor unit 20 is, for example, a wall hanging type, a ceiling embedded type, or a ceiling hanging type. The indoor unit 20 mainly includes an indoor heat exchanger 21, an indoor fan 22, and an indoor control unit 23.

  The indoor heat exchanger 21 is a heat exchanger that functions as a refrigerant evaporator during cooling operation and functions as a refrigerant condenser during heating operation. The indoor heat exchanger 21 has a plurality of heat transfer tubes (not shown) and a plurality of fins (not shown). The indoor heat exchanger 21 has a gas side connected to the gas refrigerant communication pipe GP and a liquid side connected to the liquid refrigerant communication pipe LP.

  The indoor fan 22 is a blower that generates an indoor air flow that flows into the indoor unit 20 from the outside, passes through the indoor heat exchanger 21, and flows out of the indoor unit 20. The indoor fan 22 is driven using the indoor fan motor 22a as a drive source. The driving of the indoor fan motor 22a is controlled by the indoor control unit 23 during operation, and the number of rotations is appropriately adjusted.

  The indoor control unit 23 is a functional unit that controls the operation of the actuator included in the indoor unit 20. The indoor control unit 23 includes a microcomputer configured with a CPU, a memory, and the like. The indoor control unit 23 is connected to the outdoor control unit 16 via a cable, and transmits and receives signals to and from each other at a predetermined timing. When the indoor control unit 23 receives a command to execute the defrost operation from the outdoor control unit 16, the indoor control unit 23 switches the operation state from the heating operation to the defrost operation.

  In the air conditioner 100, the same operation as that during the cooling operation is performed during the defrost operation. That is, during the defrost operation, the outdoor heat exchanger 13 functions as a refrigerant condenser, and the indoor heat exchanger 21 functions as a refrigerant evaporator. However, the point that driving of the indoor fan 22 is stopped during the defrosting operation is different from that during the cooling operation.

(2) Flow of refrigerant in air conditioner 100 (2-1) During cooling operation During cooling operation, the four-way switching valve 12 is in the state shown by the solid line in FIG. 1, and the discharge side of the compressor 11 is connected to the third refrigerant pipe P3. And the fourth refrigerant pipe P4 is connected to the gas side of the outdoor heat exchanger 13, and the suction side of the compressor 11 is connected to the gas refrigerant communication pipe GP via the first refrigerant pipe P1 and the second refrigerant pipe P2. Is done.

  When the compressor 11 is driven, 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 third refrigerant pipe P3, the four-way switching valve 12, and the fourth refrigerant pipe P4. Thereafter, the high-pressure gas refrigerant is condensed and converted into a high-pressure liquid refrigerant by exchanging heat with the outdoor air flow in the outdoor heat exchanger 13. The high-pressure liquid refrigerant that has flowed out of the outdoor heat exchanger 13 is sent to the expansion valve 14 via the fifth refrigerant pipe P5. The low-pressure refrigerant decompressed in the expansion valve 14 is sent to the indoor heat exchanger 21 via the sixth refrigerant pipe P6 and the liquid refrigerant communication pipe LP, and is evaporated by exchanging heat with the indoor air flow. It becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant flows through the gas refrigerant communication pipe GP, the first refrigerant pipe P1, and the second refrigerant pipe P2, and is sucked into the compressor 11.

  During the cooling operation, the opening degree of the expansion valve 14 and the rotation speed of the compressor 11 are adjusted as appropriate, and the refrigerant flowing through the refrigerant circuit may have a high circulation amount or a low circulation amount. .

(2-2) During heating operation During heating operation, the four-way switching valve 12 is in the state indicated by the broken line in FIG. 1, and the discharge side of the compressor 11 is heated indoors via the first refrigerant pipe P1 and the third refrigerant pipe P3. The gas side of the exchanger 21 is connected, and the suction side of the compressor 11 is connected to the gas side of the outdoor heat exchanger 13 via the second refrigerant pipe P2 and the fourth refrigerant pipe P4.

  When the compressor 11 is driven, the low-pressure gas refrigerant is compressed by the compressor 11 to become a high-pressure gas refrigerant, and the third refrigerant pipe P3, the four-way switching valve 12, the first refrigerant pipe P1, and the gas refrigerant communication pipe GP are connected. Via, it is sent to the indoor heat exchanger 21. The high-pressure gas refrigerant sent to the indoor heat exchanger 21 condenses into a high-pressure liquid refrigerant by exchanging heat with the indoor air flow, and then passes through the liquid refrigerant communication pipe LP and the sixth refrigerant pipe P6. Then, it is sent to the expansion valve 14. The high-pressure gas refrigerant sent to the expansion valve 14 is depressurized according to the opening degree of the expansion valve 14 when passing through the expansion valve 14. The low-pressure refrigerant that has passed through the expansion valve 14 flows through the fifth refrigerant pipe P5 and flows into the outdoor heat exchanger 13. The low-pressure refrigerant flowing into the outdoor heat exchanger 13 evaporates by exchanging heat with the outdoor air flow to become a low-pressure gas refrigerant, and passes through the fourth refrigerant pipe P4, the four-way switching valve 12, and the second refrigerant pipe P2. Then, it is sucked into the compressor 11.

  During the heating operation, the opening degree of the expansion valve 14 and the rotation speed of the compressor 11 are adjusted as appropriate, and the refrigerant flowing through the refrigerant circuit may have a high circulation amount or a low circulation amount.

(2-3) At the time of defrost operation At the time of defrost operation, a vapor compression refrigeration cycle is performed by the same flow as at the time of cooling operation. However, during the defrost operation, the driving of the indoor fan 22 is stopped, so that an indoor air flow that exchanges heat with the refrigerant in the indoor heat exchanger 21 is not generated.

(3) Details of Outdoor Heat Exchanger 13 FIG. 4 is an external perspective view of the outdoor heat exchanger 13. FIG. 5 is a plan view of the outdoor heat exchanger 13.

  The outdoor heat exchanger 13 is mainly composed of a central heat exchange part 30, a connection header 35, a flow divider 40 provided on the left end side of the central heat exchange part 30, a first header collecting pipe 45, and a second header collecting pipe 50. And a connecting pipe 55 (corresponding to “connecting pipe” in the claims).

(3-1) Central heat exchange unit 30
6 is a partially enlarged view of a section taken along line VI-VI in FIG. The central heat exchange unit 30 is an area where the outdoor air flow and the refrigerant passing through the outdoor heat exchanger 13 exchange heat. Specifically, the central heat exchanger 30 is a region that extends in a direction intersecting the traveling direction of the outdoor air flow in the central portion of the outdoor heat exchanger 13 and occupies most of the outdoor heat exchanger 13. The central heat exchanging portion 30 has a substantially L shape in plan view, and has a curved portion 30a between one end and the other end. The central heat exchanging unit 30 mainly includes a plurality of heat transfer tubes 31 and a plurality of heat transfer fins 32.

  The heat transfer tube 31 is a flat multi-hole tube having a plurality of flow paths 31a formed therein. The heat transfer tube 31 is made of aluminum or aluminum alloy. In the present embodiment, 72 heat transfer tubes 31 are arranged in the vertical direction in the central heat exchange section 30. However, the number of heat transfer tubes 31 included in the central heat exchange unit 30 can be changed as appropriate. The heat transfer tube 31 extends along the horizontal direction while being bent at the bending portion 30a. One end of the heat transfer tube 31 is connected to the first header collecting tube 45 and the other end is connected to the second header collecting tube 50. More specifically, the heat transfer tube 31 communicates with a first header upper space 47 and a second header upper space 501 described later, or a first header lower space 48 and a second header lower space 502 described later. Communicate. The heat transfer tube 31 has a length in the width direction extending in the front-rear direction on the left side of the curved portion 30a (on the first header collecting tube 45 and the second header collecting tube 50 side). Further, the heat transfer tube 31 has a width direction length extending in the left-right direction on the front side of the curved portion 30a.

  More specifically, the heat transfer tube 31 mainly includes a first heat transfer tube 311 and a second heat transfer tube 312. One end of the first heat transfer tube 311 is connected to the first header collecting tube 45, extends along the left-right direction, then bends at the bending portion 30a, extends along the front-rear direction, and the other end connects to the connection header 35. It is connected to the. One end of the second heat transfer tube 312 is connected to the second header collecting tube 50, extends along the left-right direction, then curves at the bending portion 30a, then extends along the front-rear direction, and the other end connects to the connection header 35. It is connected to the. As described above, each heat transfer tube 31 is composed of two flat multi-hole tubes arranged in the front-rear direction or the left-right direction. That is, the heat transfer tubes 31 extend in the horizontal direction in two rows at the same height position. The other end of the first heat transfer tube 311 and the other end of the second heat transfer tube 312 communicate with each other in a communication space CS (described later) formed in the connection header 35.

  The heat transfer fins 32 are flat members that increase the heat transfer area between the heat transfer tubes 31 and the outdoor air flow. The heat transfer fins 32 are made of aluminum or aluminum alloy. The heat transfer fins 32 extend in the vertical direction so as to intersect the heat transfer tubes 31 in the central heat exchange unit 30. The heat transfer fin 32 is formed with a plurality of notches arranged in the vertical direction, and the heat transfer tubes 31 are inserted into the notches.

  7 is a cross-sectional view of a portion A in FIG. 5 in a rear view. 8 is a cross-sectional view of a portion A in FIG. 5 in a front view. The two-dot chain lines L1 to L24 in FIG. 7 correspond to the two-dot chain lines L1 to L24 in FIG.

  The central heat exchanging part 30 is mainly divided into an upper heat exchanging part X located on the upper side and a lower heat exchanging part Y located below the upper heat exchanging part X.

  The upper heat exchange unit X has a plurality of heat exchange units arranged in the vertical direction. Specifically, the upper heat exchange unit X includes, in order from the top, a first upper heat exchange unit X1, a second upper heat exchange unit X2, a third upper heat exchange unit X3, a fourth upper heat exchange unit X4, and a fifth upper side. Heat exchange part X5, sixth upper heat exchange part X6, seventh upper heat exchange part X7, eighth upper heat exchange part X8, ninth upper heat exchange part X9, tenth upper heat exchange part X10, eleventh upper heat exchange Part X11 and the twelfth upper heat exchange part X12.

  The first upper heat exchange portion X1 is a region located above the two-dot chain line L1 (see FIGS. 7 and 8). The second upper heat exchange part X2 is a region located below the two-dot chain line L1 and above the two-dot chain line L2 (see FIGS. 7 and 8). The third upper heat exchange part X3 is a region located below the two-dot chain line L2 and above the two-dot chain line L3 (see FIGS. 7 and 8). The fourth upper heat exchange part X4 is a region located below the two-dot chain line L3 and above the two-dot chain line L4 (see FIGS. 7 and 8). The fifth upper heat exchange part X5 is a region located below the two-dot chain line L4 and above the two-dot chain line L5 (see FIGS. 7 and 8). The sixth upper heat exchange part X6 is a region located below the two-dot chain line L5 and above the two-dot chain line L6 (see FIGS. 7 and 8). The seventh upper heat exchange part X7 is a region located below the two-dot chain line L6 and above the two-dot chain line L7 (see FIGS. 7 and 8). The eighth upper heat exchange portion X8 is a region located below the two-dot chain line L7 and above the two-dot chain line L8 (see FIGS. 7 and 8). The ninth upper heat exchange part X9 is a region located below the two-dot chain line L8 and above the two-dot chain line L9 (see FIGS. 7 and 8). The tenth upper heat exchange portion X10 is a region located below the two-dot chain line L9 and above the two-dot chain line L10 (see FIGS. 7 and 8). The eleventh upper heat exchange part X11 is a region located below the two-dot chain line L10 and above the two-dot chain line L11 (see FIGS. 7 and 8). The twelfth upper heat exchange portion X12 is a region located below the two-dot chain line L11 and above the two-dot chain line L12 (see FIGS. 7 and 8).

  Each of the first upper heat exchange unit X1 to the twelfth upper heat exchange unit X12 includes four heat transfer tubes 31.

  The lower heat exchange part Y has a plurality of heat exchange parts. Specifically, the lower heat exchange unit Y includes, in order from the top, a first lower heat exchange unit Y1, a second lower heat exchange unit Y2, a third lower heat exchange unit Y3, and a fourth lower heat exchange unit. Y4, fifth lower heat exchange part Y5, sixth lower heat exchange part Y6, seventh lower heat exchange part Y7, eighth lower heat exchange part Y8, ninth lower heat exchange part Y9, tenth lower It has a side heat exchange part Y10, an eleventh lower heat exchange part Y11, and a twelfth lower heat exchange part Y12.

  The first lower heat exchange part Y1 is a region located below the two-dot chain line L12 and above the two-dot chain line L13 (see FIGS. 7 and 8). The second lower heat exchange part Y2 is a region located below the two-dot chain line L13 and above the two-dot chain line L14 (see FIGS. 7 and 8). The third lower heat exchange part Y3 is a region located below the two-dot chain line L14 and above the two-dot chain line L15 (see FIGS. 7 and 8). The fourth lower heat exchange part Y4 is a region located below the two-dot chain line L15 and above the two-dot chain line L16 (see FIGS. 7 and 8). The fifth lower heat exchange section Y5 is a region located below the two-dot chain line L16 and above the two-dot chain line L17 (see FIGS. 7 and 8). The sixth lower heat exchange part Y6 is a region located below the two-dot chain line L17 and above the two-dot chain line L18 (see FIGS. 7 and 8). The seventh lower heat exchange part Y7 is a region located below the two-dot chain line L18 and above the two-dot chain line L19 (see FIGS. 7 and 8). The eighth lower heat exchange part Y8 is a region located below the two-dot chain line L19 and above the two-dot chain line L20 (see FIGS. 7 and 8). The ninth lower heat exchange part Y9 is a region located below the two-dot chain line L20 and above the two-dot chain line L21 (see FIGS. 7 and 8). The tenth lower heat exchange part Y10 is a region located below the two-dot chain line L21 and above the two-dot chain line L22 (see FIGS. 7 and 8). The eleventh lower heat exchange part Y11 is a region located below the two-dot chain line L22 and above the two-dot chain line L23 (see FIGS. 7 and 8). The twelfth lower heat exchange part Y12 is a region located below the two-dot chain line L23 and above the two-dot chain line L24 (see FIGS. 7 and 8).

  Each of the first lower heat exchange part Y1 to the twelfth lower heat exchange part Y12 includes two heat transfer tubes 31.

(3-2) Connection header 35
9 is a cross-sectional view of a portion B in FIG. 5 in the left side view. Note that the two-dot chain lines L1 to L24 in FIG. 9 correspond to the two-dot chain lines L1 to L24 in FIGS.

  The connection header 35 is a cylindrical tube extending in the vertical direction (up and down direction). The connection header 35 constitutes one end of the outdoor heat exchanger 13. A plurality of communication spaces CS are formed in the connection header 35. In the present embodiment, the same number of communication spaces CS as the number of heat transfer tubes 31 are formed. The plurality of communication spaces CS are arranged in the vertical direction inside the connection header 35.

  The other ends of the first heat transfer tube 311 and the second heat transfer tube 312 are connected to each communication space CS. In each communication space CS, the first heat transfer tube 311 is located on the right side, and the second heat transfer tube 312 is located on the left side. The first heat transfer tube 311 and the second heat transfer tube 312 communicate with each other in the communication space CS.

(3-3) Shunt 40
FIG. 10 is an enlarged view showing a portion below the two-dot chain line L12 of FIG.

  The flow divider 40 is a cylindrical tube extending in the vertical direction. The flow divider 40 is connected to the fifth refrigerant pipe P5 in the vicinity of the lower end. The shunt 40 is adjacent to the left side of the first header collecting pipe 45. The shunt 40 communicates with the first header collecting pipe 45 through a plurality (here, 12) of communicating pipes CT. During the heating operation, the shunt 40 is connected to the first upper heat exchange part X1 to the twelfth upper heat exchange part X12 or the first lower heat exchange part Y1 to the twelfth lower heat exchange part Y12 of the central heat exchange part 30. In each part, the incoming refrigerant is divided and sent to the first header collecting pipe 45 so that the refrigerant flows at an appropriate flow rate.

  As shown in FIG. 10, a plurality of (here, 11) partition plates 40 a are arranged inside the flow divider 40. Thereby, a plurality of (here, 12) spaces are formed in the flow divider 40. Hereinafter, for convenience of explanation, the space formed in the flow divider 40 is divided into a first flow dividing chamber 401, a second flow dividing chamber 402, a third flow dividing chamber 403, a fourth flow dividing chamber 404, a first flow dividing chamber from the top to the bottom. These are referred to as a fifth branch chamber 405, a sixth branch chamber 406, a seventh branch chamber 407, an eighth branch chamber 408, a ninth branch chamber 409, a tenth branch chamber 410, an eleventh branch chamber 411, and a twelfth branch chamber 412.

  A communication pipe CT is connected to each of the first branch chamber 401 to the twelfth branch chamber 412, and each branch chamber communicates with the first header collecting pipe 45. In addition, a fifth refrigerant pipe P5 is connected to the twelfth branch chamber 412. In addition, a communication port is formed in each partition plate 40a, and each branch chamber from the first branch chamber 401 to the twelfth branch chamber 412 communicates with other branch chambers adjacent vertically. doing.

(3-4) First header collecting pipe 45
FIG. 11 is an enlarged view showing a portion above the two-dot chain line L12 in FIG.

  The first header collecting pipe 45 is a cylindrical pipe extending in the vertical direction (vertical direction). The first header collecting pipe 45 is adjacent to the right side of the flow divider 40. Note that, as shown in FIG. 7, the height (vertical length) of the first header collecting pipe 45 is larger than that of the flow divider 40.

  As shown in FIG. 10, the first header collecting pipe 45 is connected to a plurality of communication pipes CT. Further, the first header collecting pipe 45 is connected to a connecting pipe 55 as shown in FIG. More specifically, the first header collecting pipe 45 is connected to a main pipe 60, a first branch pipe BP1, and a second branch pipe BP2 of a connection pipe 55 described later. Further, the first header collecting pipe 45 is connected to each heat transfer pipe 31 (first heat transfer pipe 311) of the central heat exchanging section 30.

  Connection portions of the respective pipes connected to the first header collecting pipe 45 are arranged in the order of the second branch pipe BP2, the main pipe 60, the first branch pipe BP1, and the respective communication pipes CT from the top to the bottom. In addition, each heat transfer pipe 31 is on the opposite side (right side) of the first header collecting pipe 45 to the side (left side) to which the second branch pipe BP2, main pipe 60, first branch pipe BP1 and each communication pipe CT are connected. ) And extends rightward from the connecting portion.

  A first partition plate 46 is disposed inside the first header collecting pipe 45. As a result, the internal space of the first header collecting pipe 45 is vertically divided by the first partition plate 46, and the first header upper space 47 and the first header arranged in the vertical direction in the first header collecting pipe 45. A lower space 48 is formed.

  The first header upper space 47 is located above the first header lower space 48 and is located above the two-dot chain line L12 (see FIGS. 7 and 11). The first header upper space 47 has a larger volume than the first header lower space 48 and occupies most of the space in the first header collecting pipe 45. The connecting portion of the first header collecting pipe 45 to the main pipe 60, the second branch pipe BP2, and the first branch pipe BP1 is located in the first header upper space 47.

  The first header upper space 47 is in communication with the heat transfer tube 31 by inserting one end of each heat transfer tube 31 (more specifically, the first heat transfer tube 311) included in the upper heat exchange portion X.

  The first header lower space 48 is located below the two-dot chain line L12 (see FIGS. 7 and 10). In the first header lower space 48, the connection portion of the first header collecting pipe 45 with each communication pipe CT is located in the first header lower space 48. In the first header lower space 48, a plurality of (here, 11) second partition plates 49 are arranged. As a result, the first header lower space 48 is partitioned by the second partition plate 49, and a plurality of (here, 12) spaces arranged in the vertical direction are formed in the first header lower space 48. Yes. Hereinafter, for convenience of explanation, the space formed in the first header lower space 48 is changed from the top to the bottom in order from the first section 481, the second section 482, the third section 483, the fourth section 484, 5 section 485, 6th section 486, 7th section 487, 8th section 488, 9th section 489, 10th section 490, 11th section 491, 12th section 492.

  The sections of the first header lower space 48 have substantially the same volume. Each section of the first header lower space 48 communicates with one of the flow dividing chambers of the flow divider 40 via the communication pipe CT. Specifically, the first section 481 is the first branch chamber 401, the second section 482 is the second branch chamber 402, the third section 483 is the third branch chamber 403, and the fourth section 484 is the fourth branch chamber. 404, the fifth section 485 is the fifth branch chamber 405, the sixth section 486 is the sixth branch chamber 406, the seventh section 487 is the seventh branch chamber 407, and the eighth section 488 is the eighth branch chamber 408. The ninth section 489 is the ninth branch chamber 409, the tenth section 490 is the tenth branch chamber 410, the eleventh section 491 is the eleventh branch chamber 411, and the twelfth section 492 is the twelfth branch chamber 412. Communicate.

  Each section of the first header lower space 48 is inserted with a heat transfer pipe 31 (more specifically, one end of the first heat transfer pipe 311) of the lower heat exchange part Y included in the central heat exchange part 30. Specifically, the first section 481 is the first lower heat exchange part Y1, the second section 482 is the second lower heat exchange part Y2, and the third section 483 is the third lower heat exchange part Y3. The fourth section 484 is the fourth lower heat exchange section Y4, the fifth section 485 is the fifth lower heat exchange section Y5, the sixth section 486 is the sixth lower heat exchange section Y6, and the seventh section 487 is In the seventh lower heat exchange section Y7, the eighth section 488 is the eighth lower heat exchange section Y8, the ninth section 489 is the ninth lower heat exchange section Y9, and the eleventh section 491 is the tenth lower heat. In the exchange unit Y10, the eleventh section 491 is inserted into the respective heat transfer tubes 31 of the eleventh lower heat exchange unit Y11, and the twelfth section 492 of the twelfth lower heat exchange unit Y12 is connected to each other.

(3-5) Second header collecting pipe 50
FIG. 12 is an enlarged view showing a portion above the two-dot chain line L5 in FIG. FIG. 13 is an enlarged view showing a portion below the two-dot chain line L5 in FIG. 8 and above the two-dot chain line L11. FIG. 14 is an enlarged view showing a portion below the two-dot chain line L11 in FIG. 8 and above the two-dot chain line L24.

  The second header collecting pipe 50 is a cylindrical pipe extending in the vertical direction (vertical direction). The second header collecting pipe 50 is adjacent to the front side of the first header collecting pipe 45. The second header collecting pipe 50 is connected to each heat transfer pipe 31 included in the central heat exchange unit 30.

  Inside the second header collecting pipe 50, a first horizontal partition plate 51 (see FIG. 14) is arranged. As a result, the internal space of the second header collecting pipe 50 is partitioned up and down by the first horizontal partition plate 51, and the second header upper space 501 and the second header below are arranged in the second header collecting pipe 50 in the vertical direction. A side space 502 is formed.

  The second header upper space 501 is located above the second header lower space 502 and is located above the two-dot chain line L12 (see FIGS. 8 and 14). The second header upper space 501 has a larger volume than the second header lower space 502 and occupies most of the space in the second header collecting pipe 50.

  A plurality of second horizontal partition plates 52 extending in the horizontal direction are provided in the second header upper space 501. Each second horizontal partition plate 52 partitions the second header upper space 501 vertically. Thereby, a plurality of (here, 12) spaces are formed in the second header upper space 501 so as to be lined up and down. Hereinafter, for convenience of description, the space in the second header upper space 501 will be referred to as a first space SP1, a second space SP2, a third space SP3,. That is, among the spaces in the second header upper space 501, the first space SP1 is located at the uppermost stage, and the twelfth space SP12 is located at the lowermost stage.

  Each space in the second header upper space 501 is connected to the heat transfer tube 31 by inserting one end of each heat transfer tube 31 (more specifically, the second heat transfer tube 312) included in the upper heat exchange section X. Yes. Specifically, the first space SP1 is the first upper heat exchange part X1, the second space SP2 is the second upper heat exchange part X2, and the third space SP3 is the fourth upper heat exchange part X3. SP4 is the fourth upper heat exchange section X4, the fifth space SP5 is the fifth upper heat exchange section X5, the sixth space SP6 is the sixth upper heat exchange section X6, and the seventh space SP7 is the seventh upper heat exchange section. The eighth space SP8 of X7 is the eighth upper heat exchange unit X8, the ninth space SP9 is the ninth upper heat exchange unit X9, the tenth space SP10 is the tenth upper heat exchange unit X10, and the eleventh space SP11 is The twelfth space SP12 of the eleventh upper heat exchange part X11 is connected to the respective heat transfer tubes 31 of the twelfth upper heat exchange part X12.

  The second header lower space 502 is located below the two-dot chain line L12 (see FIGS. 8 and 14). Similar to the second header upper space 501, a plurality of second horizontal partition plates 52 are provided in the second header lower space 502. Each second horizontal partition 52 partitions the second header lower space 502 in the vertical direction. Thus, a plurality of (here, 12) spaces are formed in the second header lower space 502 so as to be lined up and down. Hereinafter, for convenience of explanation, the space in the second header lower space 502 will be referred to as a thirteenth space SP13, a fourteenth space SP14, a fifteenth space SP15,. .

  Each space in the second header lower space 502 is inserted into one end of each heat transfer tube 31 (more specifically, the second heat transfer tube 312) included in the lower heat exchange portion Y, and communicates with the heat transfer tube 31. doing. Specifically, the thirteenth space SP13 is of the first lower heat exchange unit Y1, the fourteenth space SP14 is of the second lower heat exchange unit Y2, and the fifteenth space SP15 is of the third lower heat exchange unit Y3. The sixteenth space SP16 is the fourth lower heat exchange unit Y4, the seventeenth space SP17 is the fifth lower heat exchange unit Y5, the eighteenth space SP18 is the sixth lower heat exchange unit Y6, and the nineteenth space SP19 is In the seventh lower heat exchange section Y7, the twentieth space SP20 is the eighth lower heat exchange section Y8, the twenty-first space SP21 is the ninth lower heat exchange section Y9, and the twenty-second space SP22 is the tenth lower heat. In the exchange unit Y10, the heat transfer tubes 31 of the 23rd space SP23 of the eleventh lower heat exchange unit Y11 and the 24th space SP24 of the twelfth lower heat exchange unit Y12 are inserted and communicated.

  In the present embodiment, the number of heat transfer tubes 31 to be inserted (here, four) is the same in each space in the second header upper space 501. Further, in each space in the second header lower space 502, the number of heat transfer tubes 31 to be inserted (here, two) is the same. However, the number of heat transfer tubes 31 connected to each of these spaces may be set to a different number for each space as appropriate, in view of the improvement of the refrigerant flow rate and the diversion performance during operation in the outdoor heat exchanger 13. Is possible.

  In the twelfth space SP12, a first through hole H1 is formed in the first horizontal partition 51 that partitions the twelfth space SP12 and the thirteenth space SP13. As a result, the twelfth space SP12 (that is, the lowermost space in the second header upper space 501) and the thirteenth space SP13 (that is, the uppermost space in the second header lower space 502) are the first through holes H1. It communicates through.

  Each space from the first space SP1 to the eleventh space SP11 (that is, each space in the second header upper space 501 excluding the twelfth space SP12) is connected to the fourteenth through any one of the connection pipes CP (CP1 to CP11). The space SP14 communicates with any one of the 24th space SP24 (that is, each space in the second header lower space 502 excluding the 13th space SP13).

  The communication pipe CP (CP1 to CP11) includes any one of the spaces (SP1 to SP11) in the second header upper space 501 and any one of the spaces (SP14 to SP24) in the second header lower space 502. It is piping for communication. The communication pipe CP extends along the horizontal direction, then curves and extends in the vertical direction, and further curves and extends along the horizontal direction.

  Each pipe from the first communication pipe CP1 to the eleventh communication pipe CP11 has a different pipe length (length in the vertical direction). Specifically, the first connecting pipe CP1 is the longest, the second connecting pipe CP2, the third connecting pipe CP3, the fourth connecting pipe CP4, the fifth connecting pipe CP5, the sixth connecting pipe CP6, the seventh connecting pipe CP7, The pipe length is long in the order of the eighth connection pipe CP8, the ninth connection pipe CP9, the tenth connection pipe CP10, and the eleventh connection pipe CP11.

  One end of each communication pipe CP is inserted into any space (SP1 to SP11) in the second header upper space 501 and the other end is inserted into any space (SP14 to SP24) in the second header lower space 502. Plugged in.

  Specifically, one end of the first connecting pipe CP1 is in the first space SP1, one end of the second connecting pipe CP2 is in the second space SP2, and one end of the third connecting pipe CP3 is in the third space SP3. One end of the pipe CP4 is in the fourth space SP4, one end of the fifth connection pipe CP5 is in the fifth space SP5, one end of the sixth connection pipe CP6 is in the sixth space SP6, and one end of the seventh connection pipe CP7 is in the seventh space. In SP7, one end of the eighth connecting pipe CP8 is in the eighth space SP8, one end of the ninth connecting pipe CP9 is in the ninth space SP9, one end of the tenth connecting pipe CP10 is in the tenth space SP10, and the eleventh connecting pipe CP11. Are inserted into the eleventh space SP11.

  The other end of the first connection pipe CP1 is in the 24th space SP24, the other end of the second connection pipe CP2 is in the 23rd space SP23, and the other end of the third connection pipe CP3 is in the 22nd space SP22. The other end of the pipe CP4 is in the 21st space SP21, the other end of the fifth connection pipe CP5 is in the 20th space SP20, the other end of the sixth connection pipe CP6 is in the 19th space SP19, and the other end of the seventh connection pipe CP7. Is in the 18th space SP18, the other end of the eighth connection pipe CP8 is in the 17th space SP17, the other end of the ninth connection pipe CP9 is in the 16th space SP16, and the other end of the tenth connection pipe CP10 is in the 15th space SP15. In addition, the other end of the eleventh connection pipe CP11 is inserted into the fourteenth space SP14.

  In the manner as described above, each communication pipe CP is installed between each space in the second header upper space 501 and each space in the second header lower space 502. This is because it is intended to make the outdoor heat exchanger 13 more compact by collecting them as compactly as possible and to facilitate the assembly work. That is, the compactness and assemblability of the outdoor heat exchanger 13 are improved by installing the connecting pipe CP in the above-described manner.

  In the present embodiment, the pipes adjacent in the vertical direction among the first communication pipe CP1 to the eleventh communication pipe CP11 are out of the left and right with respect to the axis extending in the vertical direction. Thereby, it is possible to install a plurality of communication pipes CP in a more compact manner, and the downsizing of the outdoor heat exchanger 13 is further promoted.

  By installing the communication pipe CP in the above-described manner, the first space SP1 (that is, the uppermost space in the second header upper space 501) is connected to the 24th space SP24 (that is, the first space SP24). And the lowermost space in the second header lower space 502). The second space SP2 is connected to the 23rd space SP23 via the second connecting pipe CP2, the third space SP3 is connected to the 22nd space SP22 via the third connecting pipe CP3, and the fourth space SP4 is connected to the fourth connecting pipe CP4. The 21st space SP21, the 5th space SP5 via the 5th connecting pipe CP5, the 20th space SP20, the 6th space SP6 via the 6th connecting pipe CP6, the 19th space SP19 and the 7th space. SP7 is connected to the eighteenth space SP18 via the seventh connecting pipe CP7, the eighth space SP8 is connected to the seventeenth space SP17 via the eighth connecting pipe CP8, and the ninth space SP9 is connected to the sixteenth space SP9 via the ninth connecting pipe CP9. The space SP16, the tenth space SP10 is the fifteenth space SP15 via the tenth connection pipe CP10, the eleventh space SP11 is the fourteenth space SP14 via the eleventh connection pipe CP11, Re communicate with each other.

  As described above, the twelfth space SP12 (that is, the lowermost space in the second header upper space 501) and the thirteenth space SP13 (that is, the uppermost space in the second header lower space 502) are: The communication is not made through the communication pipe CP but through the first through hole H1. That is, the communication pipe CP is not connected to the twelfth space SP12 and the thirteenth space SP13.

(3-6) Connecting pipe 55
FIG. 15 is an enlarged view of a portion C in FIG. 16 is a cross-sectional view taken along line FF in FIG. FIG. 17 is an enlarged view of a portion D in FIG. 18 is an enlarged view of a portion E in FIG. In addition, the broken line arrow in FIG.15, FIG17 and FIG.18 has shown the direction through which the refrigerant | coolant flows at the time of a cooling operation (or at the time of a defrost operation).

  The connection pipe 55 is connected to the other end of the fourth refrigerant pipe P4. The connection pipe 55 is a pipe that supplies the high-pressure gas refrigerant sent from the fourth refrigerant pipe P4 to the first header upper space 47 during the cooling operation or the defrost operation. The connecting pipe 55 has a main pipe 60 connected to the first header upper space 47, and a first branch pipe BP1 and a second branch pipe BP2.

(4-1) Main 60
The main pipe 60 (corresponding to “connecting pipe” in the claims) is in the horizontal direction (that is, the direction intersecting the vertical direction in which the first header collecting pipe 45 extends) in the vicinity of the connecting portion with the first header collecting pipe 45. It extends to. The main pipe 60 is connected to the first header collecting pipe 45 at a height position located in the center of the first header upper space 47. Specifically, the main pipe 60 has a height position between the sixth upper heat exchange section X6 and the seventh upper heat exchange section X7 (that is, the uppermost heat exchange section and the lowermost heat exchange section in the upper heat exchange section X). Are inserted into the first header collecting pipe 45 at a height position between the first and second sections. In other words, the main pipe 60 is between the height position at which the first branch pipe BP1 is inserted into the first header collecting pipe 45 and the height position at which the second branch pipe BP2 is inserted into the first header collecting pipe 45. Is inserted into the first header collecting pipe 45 at the height position.

  In the main pipe 60, in the vicinity of the left side of the connection portion with the first header collecting pipe 45, a first opening (not shown) into which the first branch pipe BP1 is inserted, and a second opening into which the second branch pipe BP2 is inserted ( (Not shown). The first opening faces downward and the second opening faces upward.

  The main pipe 60 includes a first joining member 61 for joining the first branch pipe BP1 and a second joining member 62 for joining the second branch pipe BP2.

  The first joining member 61 (corresponding to the “joining member” in the claims) is described as the maximum insertion amount d1 of the first branch pipe BP1 in the main pipe 60 (hereinafter simply referred to as “insertion allowance d1”). ) Is a member that is disposed to suppress). Specifically, the first joining member 61 is a plate-like member having a predetermined thickness. The first joining member 61 is curved along the outer peripheral surface of the main pipe 60. The first joining member 61 is formed with a first insertion port (not shown) for inserting the first branch pipe BP1. The inner surface of the first joining member 61 is brazed to the outer peripheral surface of the main pipe 60. In a state where the first joining member 61 is joined to the main pipe 60, the first insertion port overlaps the first opening formed in the main pipe 60.

  The second joining member 62 (corresponding to “joining member” in the claims) is described as a maximum value d2 of the insertion allowance of the second branch pipe BP2 in the main pipe 60 (hereinafter simply referred to as “insertion allowance d2”). ) Is a member that is disposed to suppress). Specifically, the second joining member 62 is a plate-like member having a predetermined thickness. The second joining member 62 is curved along the outer peripheral surface of the main pipe 60. The second joint member 62 is formed with a second insertion port (not shown) for inserting the second branch pipe BP2. The inner surface of the second joining member 62 is brazed to the outer peripheral surface of the main pipe 60. In a state where the second joining member 62 is joined to the main pipe 60, the second insertion port overlaps with the second opening formed in the main pipe 60.

(4-2) First branch pipe BP1
The first branch pipe BP1 includes a first branch pipe one end portion 71, a first branch pipe other end portion 72, and a first branch pipe main body portion 73.

  The first branch pipe one end portion 71 (corresponding to “tip portion” in the claims) is a portion inserted into the first joining member 61 and the main pipe 60. The first branch pipe one end portion 71 extends in the up-down direction. The first branch pipe one end portion 71 is inserted through the first insertion port of the first joining member 61 and the first opening of the main pipe 60, and is brazed and joined to the first joining member 61.

  The first branch pipe one end portion 71 is notched at the tip on the side to be inserted. More specifically, the first branch pipe one end portion 71 has an insertion allowance in the main pipe 60 or the first joining member 61 on the upstream side with respect to the flow path of the gas refrigerant during the cooling operation (or during the defrost operation). It is cut out so that it gets smaller. Accordingly, the gas refrigerant flowing from the main pipe 60 into the first branch pipe one end portion 71 during the cooling operation (or during the defrost operation) is compared with the case where the first branch pipe one end portion 71 is not cut out. , It is easy to flow in, and pressure loss is suppressed. That is, the gas refrigerant is stably sent from the main pipe 60 to the first branch pipe one end portion 71 during the cooling operation (or during the defrost operation).

  The other end 72 of the first branch pipe is a part inserted into the first header collecting pipe 45. The other end 72 of the first branch pipe extends in the horizontal direction (that is, the direction intersecting the vertical direction in which the first header collecting pipe 45 extends). The other end 72 of the first branch pipe is inserted into the first header collecting pipe 45 at the height position of the twelfth upper heat exchange section X12 (that is, the height position of the lowest heat exchange section in the upper heat exchange section X). It is. More specifically, the first branch pipe other end 72 is inserted into the first header collecting pipe 45 at a height position of the lowermost heat transfer pipe 31 included in the upper heat exchange part X. That is, the other end 72 of the first branch pipe is connected to the lowermost space (the twelfth space) in the first header upper space 47 that communicates with the uppermost space (the thirteenth space SP13) in the second header lower space 502. SP12) is connected to the first header collecting pipe 45 at the same height position as the twelfth upper heat exchange section X12 including the heat transfer pipe 31 communicating with SP12).

  The first branch pipe main body 73 is a part that connects the first branch pipe one end 71 and the first branch pipe other end 72. The first branch pipe main body 73 extends from the first branch pipe one end 71 along the downward direction, is curved rightward, and is connected to the first branch pipe other end 72.

(4-3) Second branch pipe BP2
The second branch pipe BP2 includes a second branch pipe one end portion 81, a second branch pipe other end portion 82, and a second branch pipe main body portion 83.

  The second branch pipe one end portion 81 (corresponding to a “tip portion” in the claims) is a portion inserted into the second joining member 62 and the main pipe 60. The second branch pipe one end portion 81 extends in the vertical direction. The second branch pipe one end portion 81 is inserted through the second insertion port of the second joint member 62 and the second opening of the main pipe 60, and is brazed and joined to the second joint member 62.

  The second branch pipe one end portion 81 is located upstream of the first branch pipe one end portion 71 with respect to the flow path of the gas refrigerant during the cooling operation (or during the defrost operation). That is, the second branch pipe BP2 branches in the main pipe 60 of the connection pipe 55 at a position upstream of the position where the first branch pipe BP1 branches from the position where the first branch pipe BP1 branches. Accordingly, the gas refrigerant flowing in the main pipe 60 during the cooling operation (or during the defrost operation) flows into the second branch pipe one end portion 81 before the first branch pipe one end portion 71. As a result, during the cooling operation (or during the defrost operation), the gas refrigerant flowing into the second branch pipe one end portion 81 has a larger flow rate than the gas refrigerant flowing into the first branch pipe one end portion 71. The gas refrigerant is stably sent from the pipe 60 to the second branch pipe one end portion 81.

  The distal end of the second branch pipe one end portion 81 is notched. More specifically, the second branch pipe one end 81 has an insertion allowance in the main pipe 60 or the second joining member 62 on the upstream side with respect to the flow path of the gas refrigerant during the cooling operation (or during the defrost operation). It is cut out so that it gets smaller. Thereby, the gas refrigerant flowing into the second branch pipe one end portion 81 from the main pipe 60 during the cooling operation (or defrost operation) is compared with the case where the second branch pipe one end portion 81 is not cut out. , It is easy to flow in, and pressure loss is suppressed. That is, during the cooling operation (or defrost operation), the gas refrigerant is stably sent from the main pipe 60 to the second branch pipe one end portion 81.

  The other end 82 of the second branch pipe is a part inserted into the first header collecting pipe 45. The other end 82 of the second branch pipe extends in the horizontal direction (that is, the direction intersecting the vertical direction in which the first header collecting pipe 45 extends). The other end 82 of the second branch pipe is inserted into the first header collecting pipe 45 at the height position of the first upper heat exchange section X1 (that is, the height position of the uppermost heat exchange section in the upper heat exchange section X). It is. More specifically, the second branch pipe other end portion 82 is inserted into the first header collecting pipe 45 at the height position of the uppermost heat transfer pipe 31 included in the upper heat exchange section X. That is, the other end 82 of the second branch pipe is the uppermost space (first space) in the second header upper space 501 communicating with the lowermost space (24th space SP24) in the second header lower space 502. SP1) is connected to the first header collecting pipe 45 at the same height position as the first upper heat exchanging portion X1 including the heat transfer pipe 31 communicating with SP1).

  The second branch pipe main body 83 is a part that connects the second branch pipe one end 81 and the second branch pipe other end 82. The second branch pipe main body 83 extends from the second branch pipe one end portion 81 in the upward direction, is curved rightward, and is connected to the second branch pipe other end portion 82.

(4-4) Inner diameter and insertion allowance of first branch pipe BP1 and second branch pipe BP2 In this embodiment, inner diameters (W1, W2, W3 of main pipe 60, first branch pipe BP1 and second branch pipe BP2). ) Are arranged in descending order, the inner diameter W1 of the main pipe 60, the inner diameter W3 of the second branch pipe BP2, and the inner diameter W2 of the first branch pipe BP1 are obtained. That is, the inner diameter W3 of the second branch pipe BP2 is larger than the inner diameter W2 of the first branch pipe BP1. As a result, during the cooling operation (or during the defrost operation), the flow rate of the gas refrigerant flowing through the second branch pipe BP2 is larger than the gas refrigerant flowing through the first branch pipe BP1.

  Further, the insertion allowance d2 of the second branch pipe BP2 in the main pipe 60 is smaller than the insertion allowance d1 of the first branch pipe BP1 in the main pipe 60. Therefore, during the cooling operation (or during the defrost operation), the gas refrigerant flowing from the main pipe 60 into the second branch pipe BP2 is more stable than the gas refrigerant flowing from the main pipe 60 into the first branch pipe BP1. Inflow. As a result, the flow rate of the gas refrigerant flowing through the first branch pipe BP1 during the cooling operation (or during the defrost operation) is further increased.

(5) Refrigerant flow in the outdoor heat exchanger 13 (5-1) During cooling operation and defrost operation During cooling operation (or during defrost operation), a high-pressure gas refrigerant flows from the fourth refrigerant pipe P4 to the connection pipe 55. Flows in. The high-pressure gas refrigerant that has flowed into the connection pipe 55 flows through the main pipe 60, the first branch pipe BP1, or the second branch pipe BP2 of the connection pipe 55, and eventually reaches the first header collecting pipe 45.

  The high-pressure gas refrigerant that has reached the first header collecting pipe 45 flows into the first header upper space 47. The gas refrigerant flowing into the first header upper space 47 flows out to each heat transfer tube 31 (first heat transfer tube 311) of the upper heat exchange section X. The gas refrigerant that has flowed into the first heat transfer tube 311 flows through the first heat transfer tube 311 while exchanging heat with the outdoor air flow (or frost attached to the upper heat exchange portion X), and eventually reaches the connection header 35. The refrigerant reaching the connection header 35 flows out to the second heat transfer tube 312 through the communication space CS. The refrigerant flowing into the second heat transfer pipe 312 flows through the second heat transfer pipe 312 while exchanging heat with the outdoor air flow (or frost attached to the upper heat exchange portion X), and eventually reaches the second header collecting pipe 50. .

  The refrigerant that has reached the second header collecting pipe 50 flows out to each space (SP1 to SP12) of the corresponding second header upper space 501. The refrigerant that has flowed from the first space SP1 in the second header collecting pipe 50 into each space of the eleventh space SP11 flows out to the connected connection pipe CP. The refrigerant that has flowed into the twelfth space SP12 in the second header collecting pipe 50 flows in the first through-hole H1 direction (downward), and flows out to the thirteenth space SP13 through the first through-hole H1. The refrigerant flowing into the thirteenth space SP13 flows out to the second heat transfer tubes 312 of the first lower heat exchange part Y1. The refrigerant that has flowed from the fourteenth space SP14 into each space of the twenty-fourth space SP24 flows out to the second heat transfer tubes 312 of the corresponding lower heat exchange section Y (Y2 to Y12).

  The refrigerant flowing into the second heat transfer pipe 312 of the lower heat exchange section Y (Y2 to Y12) exchanges heat with the outdoor air flow (or frost adhering to the lower heat exchange section Y) in the second heat transfer pipe 312. And eventually reach the connection header 35.

  The refrigerant that has reached the connection header 35 flows out to the first heat transfer tube 311 through the communication space CS. The refrigerant flowing into the first heat transfer tube 311 flows through the first heat transfer tube 311 while exchanging heat with the outdoor air flow (or frost attached to the lower heat exchange portion Y), and eventually reaches the first header collecting tube 45. To do.

  The refrigerant that has reached the first header collecting pipe 45 flows out to the sections (481 to 492) of the first header lower space 48. The refrigerant that has flowed into each section of the first header lower space 48 reaches the flow divider 40 via the communication pipe CT.

  The refrigerant that has reached the flow divider 40 flows out into the corresponding flow dividing chamber (any one of 401 to 412). The refrigerant flowing into each branch chamber (excluding the twelfth branch chamber 412) flows toward the branch chamber located below through the communication port. The refrigerant flowing into the twelfth branch chamber 412 flows out to the fifth refrigerant pipe P5.

(5-2) During heating operation During the heating operation, liquid refrigerant flows into the twelfth branch chamber 412 of the flow divider 40 from the fifth refrigerant pipe P5. A part of the refrigerant flowing into the twelfth branch chamber 412 reaches the first header collecting pipe 45 via the communication pipe CT, and the other part of the refrigerant goes to each branch chamber located above via the communication port. Flowing. A part of the refrigerant flowing into each branch chamber (excluding the first branch chamber 401) reaches the first header collecting pipe 45 via the communication pipe CT, and the other part is upward via the communication port. It flows toward each diversion chamber located at. The refrigerant flowing into the first branch chamber 401 reaches the first header collecting pipe 45 through the communication pipe CT.

  The refrigerant that has reached the first header collecting pipe 45 flows into the sections (481 to 492) of the first header lower space 48. The liquid refrigerant that has flowed into each section of the first header lower space 48 flows out to the corresponding first heat transfer tube 311 of the lower heat exchange section Y. The gas refrigerant that has flowed into the first heat transfer tube 311 flows through the first heat transfer tube 311 while exchanging heat with the outdoor air flow, and eventually reaches the connection header 35.

  The refrigerant reaching the connection header 35 flows out to the second heat transfer tube 312 through the communication space CS. The refrigerant flowing into the second heat transfer pipe 312 flows through the second heat transfer pipe 312 while exchanging heat with the outdoor air flow, and eventually reaches the second header collecting pipe 50.

  The refrigerant that has reached the second header collecting pipe 50 flows out to any space (SP14 to SP24) in the corresponding second header lower space 502. The refrigerant that has flowed into the thirteenth space SP13 in the second header collecting pipe 50 flows out into the twelfth space SP12 through the first through hole H1. The refrigerant that has flowed from the 14th space SP14 in the second header collecting pipe 50 into each space of the 24th space SP24 flows out to the connected connection pipe CP. The refrigerant that has flowed into the communication pipe CP flows out to any of the spaces (SP1 to SP11) in the corresponding second header upper space 501. The refrigerant that has flowed into the spaces from the first space SP1 to the twelfth space SP12 flows out to the second heat transfer tube 312 connected to the space.

  The refrigerant flowing into the second heat transfer tube 312 from each space in the second header upper space 501 flows through the second heat transfer tube 312 while exchanging heat with the outdoor air flow, and eventually reaches the connection header 35. The refrigerant that has reached the connection header 35 flows out to the first heat transfer tube 311 through the communication space CS. The refrigerant flowing into the first heat transfer tube 311 flows through the first heat transfer tube 311 while exchanging heat with the outdoor air flow, and eventually reaches the first header collecting tube 45.

  The refrigerant that has reached the first header collecting pipe 45 flows into the first header upper space 47. The refrigerant flowing into the first header upper space 47 flows out to the main pipe 60, the first branch pipe BP1, or the second branch pipe BP2 of the connection pipe 55. The refrigerant that has flowed through the main pipe 60, the first branch pipe BP1, or the second branch pipe BP2 of the connection pipe 55 eventually flows out to the fourth refrigerant pipe P4.

(6) Defrosting promotion function of the outdoor heat exchanger 13 A heat exchanger that is installed outside like the outdoor heat exchanger 13 and functions as an evaporator during heating operation is generally frosted during heating operation in winter. In particular, the lower heat exchange part Y is likely to be frosted. In addition, in a heat exchanger that is long in the longitudinal direction (vertical direction), such as the outdoor heat exchanger 13, generally, the flow rate of the high-pressure gas refrigerant supplied to each heat exchange unit during the defrost operation is greatly varied. In the heat exchanging part where the high-pressure gas refrigerant is not stably supplied, the time for defrosting tends to increase.

  However, in the outdoor heat exchanger 13 of the present embodiment, the first branch pipe BP1 that supplies the high-pressure gas refrigerant communicates with the uppermost space (13th space SP13) in the second header lower space 502. The twelfth upper heat exchange part X12 including the heat transfer tube 31 communicating with the twelfth space SP12 in the second header upper space 501 is connected to the first header collecting pipe 45 at the same height position.

  Further, the second branch pipe BP2 that supplies the high-pressure gas refrigerant is the first space SP1 in the second header upper space 501 that communicates with the lowermost space (the 24th space SP24) in the second header lower space 502. Is connected to the first header collecting pipe 45 at the same height as the first upper heat exchange part X1 including the heat transfer pipe 31 communicating with the first upper heat exchange part X1.

  Further, the main pipe 60 for supplying the high-pressure gas refrigerant is connected to the first header collecting pipe 45 at an intermediate height position between the first branch pipe BP1 and the second branch pipe BP2.

  Thereby, during defrost operation, the variation in the flow rate of the high-pressure gas refrigerant supplied to each heat exchange unit is suppressed, and in particular, the refrigerant that leads to each heat exchange unit of the lower heat exchange unit Y where frost easily attaches. A high-pressure gas refrigerant is stably supplied to the flow path. As a result, in the defrost operation, the time required for defrosting is shortened in the specific heat exchange part of the lower heat exchange part Y that is likely to increase the time required for defrosting, and the defrosting is promoted.

(7) Features (7-1)
In the above embodiment, the first branch pipe BP1 that supplies high-pressure gas refrigerant during the defrost operation is the second header upper space 501 that communicates with the uppermost space (the thirteenth space SP13) in the second header lower space 502. The twelfth upper heat exchange part X12 including the heat transfer pipe 31 communicating with the inner twelfth space SP12 is connected to the first header collecting pipe 45 at the same height position. In addition, the second branch pipe BP2 that supplies high-pressure gas refrigerant during the defrost operation is the second branch upper space 501 in the second header upper space 501 that communicates with the lowermost space (24th space SP24) in the second header lower space 502. The first upper heat exchanging portion X1 including the heat transfer tube 31 communicating with the one space SP1 is connected to the first header collecting tube 45 at the same height position.

  Thus, during the defrost operation, the first space SP1 in the second header upper space 501 communicating with the uppermost space (the thirteenth space SP13) in the second header lower space 502 in the first header collecting pipe 45. The heat transfer tube 31 communicated with the space, and the space (first space SP1) in the second header upper space 501 communicated with the lowermost space (24th space SP24) in the second header lower space 502. The high-pressure gas refrigerant is supplied at a position close to the inlet 31. That is, the gas refrigerant is supplied to a position close to the inlet of the refrigerant flow path leading to the uppermost and lowermost spaces (the thirteenth space SP13 and the twenty-fourth space SP24) in the second header lower space 502. It has become. As a result, the lower heat exchange section in which the gas refrigerant is stably supplied to the uppermost and lowermost spaces (the thirteenth space SP13 and the twenty-fourth space SP24) in the second header lower space 502 and frost is likely to adhere thereto. The time required for defrosting in Y is shortened.

(7-2)
In the above embodiment, the first branch pipe BP1 has the same height as the twelfth upper heat exchange part X12 including the heat transfer pipe 31 communicating with the lowest space (the twelfth space SP12) in the second header upper space 501. It is connected to the first header collecting pipe 45 at the position. The second branch pipe BP2 has the first header at the same height as the first upper heat exchange part X1 including the heat transfer pipe 31 communicating with the uppermost space (first space SP1) in the second header upper space 501. It is connected to the collecting pipe 45. The main pipe 60 of the connection pipe 55 is connected to the first header collecting pipe 45 at a height position between the first branch pipe other end 72 and the second branch pipe other end 82.

  Thus, during the defrost operation, the high-pressure gas refrigerant supplied to the first header upper space 47 is stably supplied to each heat transfer tube 31 communicating with the first header upper space 47, and is transferred in the upper heat exchange section X. Variations in the flow rate of the gas refrigerant flowing through the heat pipe 31 are suppressed. In other words, the gas refrigerant is stably supplied to the refrigerant flow paths communicating with the spaces (SP1 to SP24) in the second header upper space 501 and the second header lower space 502. As a result, the gas refrigerant is stably supplied to each space in the second header upper space 501 and the second header lower space 502, and the flow rate variation of the gas refrigerant flowing through the heat transfer pipe 31 in the lower heat exchange section Y varies. It is supposed to be suppressed.

(7-3)
In the above embodiment, the second branch pipe BP2 branches in the main pipe 60 of the connection pipe 55 at a position upstream of the position where the first branch pipe BP1 branches from the position where the first branch pipe BP1 branches. Accordingly, the gas refrigerant flowing in the main pipe 60 during the defrost operation flows into the second branch pipe one end portion 81 before the first branch pipe one end portion 71. As a result, during the defrost operation, the flow rate of the gas refrigerant flowing into the second branch pipe BP2 is larger than that of the gas refrigerant flowing into the first branch pipe BP1. That is, the gas refrigerant is stably supplied to the refrigerant flow path leading to the lowermost space (24th space SP24) in the second header lower space 502.

(7-4)
In the above embodiment, the first branch pipe one end portion 71 and the second branch pipe one end portion 81 inserted into the main pipe 60 of the connection pipe 55 are notched at the distal ends. More specifically, the first branch pipe one end portion 71 and the second branch pipe one end portion 81 are configured such that the insertion allowance in the main pipe 60 becomes smaller toward the upstream side with respect to the flow path of the gas refrigerant during the defrost operation. It is cut out. Thus, the gas refrigerant flowing from the main pipe 60 into the first branch pipe one end 71 and the second branch pipe one end 81 during the defrost operation is cut off by the first branch pipe one end 71 and the second branch pipe one end 81. Compared with the case where it is not lacking, it is easier to flow in and pressure loss is suppressed. That is, during the defrost operation, the gas refrigerant is stably sent from the main pipe 60 to the first branch pipe BP1 and the second branch pipe BP2. As a result, the high-pressure gas refrigerant is stably supplied to the refrigerant flow path leading to the uppermost and lowermost spaces (the thirteenth space SP13 and the twenty-fourth space SP24) in the second header lower space 502. It has become.

(7-5)
In the above embodiment, the inner diameter W3 of the second branch pipe BP2 is larger than the inner diameter W2 of the first branch pipe BP1. Thereby, the high-pressure gas refrigerant is stably supplied to the second branch pipe BP2 during the defrost operation. That is, the high-pressure gas refrigerant is stably supplied to the refrigerant flow path leading to the lowermost space (24th space SP24) in the second header lower space 502.

(7-6)
In the said embodiment, 1st branch pipe BP1 and 2nd branch pipe BP2 are inserted in the 1st junction member 61 or the 2nd junction member 62, and are joined with the 1st junction member 61 or the 2nd junction member 62. . Thereby, the insertion allowances d1 and d2 of the insertion part of the 1st branch pipe BP1 and the 2nd branch pipe BP2 in the main pipe 60 of the connection pipe 55 are suppressed. As a result, during defrost operation, the pressure loss of the gas refrigerant flowing in the main pipe 60 is suppressed, and the gas refrigerant is more likely to flow into the first branch pipe BP1 and the second branch pipe BP2. In other words, the high-pressure gas refrigerant is more stably supplied to the refrigerant flow paths leading to the spaces (SP13 to SP24) in the second header lower space 502.

(7-7)
In the above embodiment, the insertion allowance d2 of the second branch pipe BP2 in the main pipe 60 of the connection pipe 55 is smaller than the insertion allowance d1 of the first branch pipe BP1 in the main pipe 60 of the connection pipe 55. Thereby, the high-pressure gas refrigerant is stably supplied to the second branch pipe BP2 during the defrost operation. That is, the high-pressure gas refrigerant is stably supplied to the refrigerant flow path leading to the lowermost space (24th space SP24) in the second header lower space 502.

(7-8)
In the above embodiment, each heat transfer tube 31 has one end of the first heat transfer tube 311 connected to the first header collecting tube 45 and the other end connected to the connection header 35, and one end of the second heat transfer tube 312 is the second. The other end is connected to the connecting header 35 while being connected to the header collecting pipe 50. The other end of the first heat transfer tube 311 and the other end of the second heat transfer tube 312 communicate with each other in the communication space CS in the connection header 35. In this way, the heat transfer tube 31 includes the first heat transfer tube 311 and the second heat transfer tube 312, so that the area to which frost adheres during the heating operation in winter or the like is increased, but the defrosting is concerned. Time has been shortened.

(8) Modification (8-1) Modification A
In the above embodiment, the present invention is applied to the outdoor heat exchanger 13. However, the present invention is not limited to this, and the present invention may be applied to headers of other heat exchangers. For example, the present invention is not a so-called two-surface heat exchanger having a substantially L shape in a plan view like the outdoor heat exchanger 13, but a so-called three-surface heat exchanger having a substantially C-shape in a plan view, The present invention may be applied to a so-called four-surface heat exchanger having a substantially rectangular shape.

(8-2) Modification B
In the above embodiment, the heat transfer tube 31 includes the first heat transfer tube 311 and the second heat transfer tube 312 and extends in two rows at the same height position. However, the present invention is not limited to this, and the heat transfer tube 31 is configured by only one of the first heat transfer tube 311 and the second heat transfer tube 312, and the other may be omitted. In such a case, the connection header 35 may be omitted, and one end of one heat transfer tube may be connected to the first header collecting tube 45 and the other end connected to the second header collecting tube 50. Further, one of the first header collecting pipe 45 and the second header collecting pipe 50 may be arranged at the position of the connection header 35.

(8-3) Modification C
In the embodiment described above, the outdoor unit 10 is configured to blow forward the air sucked during operation in the forward direction (horizontal direction). However, the outdoor unit 10 is not limited to this, For example, you may be comprised so that the inhaled air may be blown out upwards.

(8-4) Modification D
In the above embodiment, the connecting pipe 55 has the same height as the first branch pipe BP1 connected to the first header collecting pipe 45 at the same height position as the twelfth upper heat exchange part X12 and the first upper heat exchange part X1. And a second branch pipe BP2 connected to the first header collecting pipe 45 at this position. However, the connecting pipe 55 may have a further branch pipe. For example, the connecting pipe 55 may have another branch pipe connected to the first header collecting pipe 45 at an intermediate height position between the first branch pipe BP1 and the main pipe 60. Further, the connecting pipe 55 may have another branch pipe connected to the first header collecting pipe 45 at an intermediate height position between the second branch pipe BP2 and the main pipe 60.

(8-5) Modification E
In the embodiment described above, the first branch pipe BP1 and the second branch pipe BP2 are inserted and joined to the first joining member 61 or the second joining member 62. However, the first joining member 61 or the second joining member 62 is not necessarily required and may be omitted. In such a case, the first branch pipe BP1 and the second branch pipe BP2 may be configured to be directly inserted into the main pipe 60 and brazed.

(8-6) Modification F
In the above embodiment, the inner diameter W3 of the second branch pipe BP2 is configured to be larger than the inner diameter W2 of the first branch pipe BP1. However, the inner diameter W2 of the first branch pipe BP1 and the inner diameter W3 of the second branch pipe BP2 may be configured to have the same size. Further, the inner diameter W2 of the first branch pipe BP1 may be configured to be larger than the inner diameter W3 of the second branch pipe BP2.

(8-7) Modification G
In the embodiment described above, the second branch pipe BP2 is branched in the main pipe 60 at a position on the upstream side of the flow path of the gas refrigerant from the position where the first branch pipe BP1 branches. However, it is not always necessary for the second branch pipe BP2 to branch at a position upstream of the flow path of the gas refrigerant in the main pipe 60 from the position where the first branch pipe BP1 branches. For example, the second branch pipe BP2 may be configured to branch at a position in the main pipe 60 that overlaps the position where the first branch pipe BP1 branches in plan view. Further, the second branch pipe BP2 may be configured to branch in the main pipe 60 at a position downstream of the flow path of the gas refrigerant from the position where the first branch pipe BP1 branches.

(8-8) Modification H
In the above embodiment, the first branch pipe one end portion 71 of the first branch pipe BP1 and the second branch pipe one end portion 81 of the second branch pipe BP2 are cut so that the gas refrigerant can easily flow stably during the defrost operation. It was missing. However, the first branch pipe one end portion 71 and the second branch pipe one end portion 81 do not necessarily need to be cut out in this way.

(8-9) Modification I
In the above embodiment, the insertion allowance d2 of the second branch pipe BP2 in the main pipe 60 of the connection pipe 55 is configured to be smaller than the insertion allowance d1 of the first branch pipe BP1. However, the insertion allowance d2 is not necessarily configured to be smaller than the insertion allowance d1. For example, the insertion allowance d2 may be configured to be the same as the insertion allowance d1, or the insertion allowance d2 may be configured to be larger than the insertion allowance d1.

(8-10) Modification J
In the above embodiment, in the main pipe 60 of the connecting pipe 55, the insertion allowances d1 and d2 are larger than 0 (that is, the first branch pipe BP1 and the second branch pipe BP2 have a predetermined volume in the main pipe 60). ) Aspect, the first branch pipe BP1 and the second branch pipe BP2 were configured. However, the present invention is not limited to this, and the insertion allowance d1 or d2 is 0 (that is, the first branch pipe BP1 or the second branch pipe BP2 does not have a predetermined volume in the main pipe 60). The first branch pipe BP1 or the second branch pipe BP2 may be configured. In such a case, the first branch pipe BP1 or the second branch pipe BP2 is inserted into the first joint member 61 or the second joint member 62 and is not inserted into the main pipe 60. As a result, the pressure loss of the gas refrigerant flowing from the main pipe 60 to the first branch pipe BP1 or the second branch pipe BP2 during the defrost operation is further suppressed, and the gas is more stably supplied to the first branch pipe BP1 or the second branch pipe BP2. A refrigerant will be supplied.

(8-11) Modification K
In the said embodiment, the upper side heat exchange part X contained 12 heat exchange parts (X1-X12), and the lower side heat exchange part Y contained 12 heat exchange parts (Y1-Y12). However, the number of heat exchanging parts included in the upper heat exchanging part X and the lower heat exchanging part Y can be changed as appropriate, and may be more or less than twelve. For example, the number of heat exchange units included in the upper heat exchange unit X and the lower heat exchange unit Y may be changed to 16 or 8.

  Further, the number of heat exchange units included in the upper heat exchange unit X and the number of heat exchange units included in the lower heat exchange unit Y are not necessarily the same and may be different. For example, the number of heat exchange units included in the upper heat exchange unit X may be twelve, while the number of heat exchange units included in the lower heat exchange unit Y may be eight.

  The number of flow dividing chambers (401 to 412) formed in the flow divider 40, the number of sections (481 to 492) formed in the first header lower space 48, the second header upper space 501 and the second header. Regarding the number of spaces (SP1 to SP24) formed in the lower space 502 and the number of connecting pipes CP (CP1 to CP11), the heat exchange part included in the upper heat exchange part X and the lower heat exchange part Y What is necessary is just to change suitably according to the number of the heat exchange parts contained.

(8-12) Modification L
In the above embodiment, the twelfth space SP12 in the second header upper space 501 and the thirteenth space SP13 in the second header lower space 502 communicate with each other via the first through hole H1. However, instead of this, the twelfth space SP12 and the thirteenth space SP13 may be configured to communicate with each other via the connection pipe CP.

(8-13) Modification M
In the above embodiment, each space (SP1 to SP12) in the second header upper space 501 communicates with one of the spaces (SP13 to SP24) in the second header lower space 502 in a one-to-one relationship. It was. However, instead of this, the space (SP1 to SP12) in the second header upper space 501 is one-to-many, many-to-one, or many with the space (SP13 to SP24) in the second header lower space 502. You may comprise so that it may communicate in a many-to-many relationship.

  For example, the first space SP1 may be configured to communicate with the twenty-third space SP23 and the twenty-fourth space SP24 so as to have a one-to-many relationship. Moreover, you may comprise so that 1st space SP1 and 2nd space SP2 and 24th space SP24 may be connected so that it may become many-to-one relationship. Moreover, you may comprise so that 1st space SP1 and 2nd space SP2 and 23rd space SP23 and 24th space SP24 may be connected so that it may become a many-to-many relationship.

  The present invention is applicable to a heat exchanger.

13: Outdoor heat exchanger 30: Central heat exchange part 30a: Curved part 31: Heat transfer pipe 31a: Flow path 35: Connection header 40: Divider 45: First header collecting pipe 46: First partition plate 47: First header Upper space 48: first header lower space 49: second partition plate 50: second header collecting pipe 51: first horizontal partition plate 52: second horizontal partition plate 55: connecting pipe (connection pipe)
60: Main pipe (connection piping)
61: 1st joining member (joining member)
62: Second joining member (joining member)
71: One end (first end) of the first branch pipe
72: First branch pipe other end 73: First branch pipe main body 81: Second branch pipe one end (tip)
82: Second branch pipe other end part 83: Second branch pipe main body part 100: Air conditioner 311: First heat transfer pipe 312: Second heat transfer pipes 401 to 412: First branching chamber to twelfth branching chamber 481 to 492 : First section to twelfth section 501: second header upper space 502: second header lower space BP1: first branch pipe BP2: second branch pipe CP: communication pipe CP1 to CP11: first communication pipe CP1 to second 11 connection pipe CP11
CS: Communication space CT: Communication pipe d1: Insertion allowance d2: Insertion allowance H1: First through hole P4: Fourth refrigerant pipe P5: Fifth refrigerant pipes SP1-SP24: First to 24th spaces W1-W3 : Inner diameter X: Upper heat exchange part X1 to X12: First upper heat exchange part to twelfth upper heat exchange part (heat exchange part)
Y: Lower heat exchange part Y1-Y12: 1st lower heat exchange part-12th lower heat exchange part (heat exchange part)

JP 2013-155961 A

Claims (8)

A first header collecting pipe (45) extending in the vertical direction and partitioned into a first header upper space (47) and a first header lower space (48) positioned below the first header upper space; ,
A second header collecting pipe (50) extending in the vertical direction and partitioned into a second header upper space (501) and a second header lower space (502) positioned below the second header upper space. ,
A plurality of heat transfer tubes (31) extending along the horizontal direction, and a plurality of heat exchange sections (X1 to X12, Y1 to Y12) arranged in the vertical direction;
A connection pipe (55, 60) that communicates with the first header upper space and supplies a high-pressure gas refrigerant;
With
The heat transfer tube communicates with the first header upper space and the second header upper space, or the first header lower space and the second header lower space,
Inside the second header upper space and the second header lower space, a plurality of spaces arranged in the vertical direction are formed,
Each space in the second header upper space communicates with one of the spaces in the second header lower space,
The connecting pipe is
The same height as the heat exchange part (X12) including the heat transfer pipe communicating with the space (SP12) in the second header upper space communicating with the uppermost space (SP13) in the second header lower space. A first branch pipe (BP1) connected to the first header collecting pipe at a position;
The same height as the heat exchanging part (X1) including the heat transfer pipe communicating with the space (SP1) in the second header upper space communicating with the lowermost space (SP24) in the second header lower space. A second branch pipe (BP2) connected to the first header collecting pipe at the position;
including,
Heat exchanger (13). The first branch pipe has the first header collecting pipe at the same height as the heat exchange part (X12) including the heat transfer pipe communicating with the lowermost space (SP12) in the upper space of the second header. Connected to
The second branch pipe has the first header collecting pipe at the same height as the heat exchange part (X1) including the heat transfer pipe communicating with the uppermost space (SP1) in the upper space of the second header. Connected to
The connection pipe (60) is connected to the first header collecting pipe at a height position between the first branch pipe and the second branch pipe.
The heat exchanger (13) according to claim 1. The second branch pipe branches at a position upstream of the flow path of the gas refrigerant from a position where the first branch pipe branches in the connection pipe.
The heat exchanger (13) according to claim 1 or 2. The first branch pipe and the second branch pipe are notched at the tip end portions (71, 81) inserted into the connection pipe.
The heat exchanger (13) according to any one of claims 1 to 3. The inner diameter (W3) of the second branch pipe is larger than the inner diameter (W2) of the first branch pipe,
The heat exchanger (13) according to any one of claims 1 to 4. The first branch pipe and the second branch pipe are inserted into a joining member (61, 62) joined to an outer peripheral surface of the connection pipe, and joined to the joining member.
The heat exchanger (13) according to any one of claims 1 to 5. The insertion allowance (d2) in the connection pipe of the second branch pipe is smaller than the insertion allowance (d1) in the connection pipe of the first branch pipe,
The heat exchanger (13) according to any one of claims 1 to 6. It further includes a connection header that extends in the vertical direction and is formed with a plurality of communication spaces (CS) arranged in the vertical direction.
Each of the heat transfer tubes includes a first heat transfer tube (311) and a second heat transfer tube (312),
The first heat transfer tube has one end connected to the first header collecting tube and the other end connected to the connection header,
The second heat transfer tube has one end connected to the second header collecting tube and the other end connected to the connection header,
The other end of the first heat transfer tube and the other end of the second heat transfer tube communicate with each other in the communication space.
A heat exchanger (13) according to any one of the preceding claims.

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