JP5716499B2 - Heat exchanger and air conditioner - Google Patents

Description

  The present invention relates to a heat exchanger in which a plurality of flat tubes are connected in parallel to a header collecting tube, and an air conditioner including the heat exchanger, and is a measure for preventing drift of refrigerant in each flat tube. It is concerned.

  Conventionally, a heat exchanger including a plurality of flat tubes and a header collecting tube to which the plurality of flat tubes are connected in parallel is known. For example, Patent Document 1 discloses this type of heat exchanger.

  The heat exchanger of Patent Document 1 includes two hollow header collecting pipes and a plurality of flat tubes connected in parallel to both header collecting pipes. Each header collecting pipe extends in the vertical direction. The plurality of flat tubes are arranged in the vertical direction so that the flat side surfaces face each other. For example, corrugated fins are interposed between adjacent flat tubes.

  The heat exchanger of Patent Document 1 constitutes a condenser such as a room air conditioner. That is, a high-pressure gas refrigerant compressed by a compressor or the like is sent to the heat exchanger. The gas refrigerant flows through one header collecting pipe and is divided into each flat pipe, and then sent to the other header collecting pipe. Under the present circumstances, the heat | fever of a refrigerant | coolant is provided to air by heat-exchanging the air which passes a heat exchanger, and the refrigerant | coolant which flows through each flat tube.

JP-A-9-113177

  By the way, the heat exchanger as described above can also be applied to an evaporator through which a low-pressure refrigerant containing liquid flows. However, in a heat exchanger configured to flow this refrigerant from the lower part to the upper part of the header collecting pipe, it is necessary to flow a relatively high-density liquid refrigerant upward against its own weight. For this reason, in the header collecting pipe, the high-density liquid refrigerant tends to flow into the lower flat tube, and the amount of liquid refrigerant flowing into the upper flat tube tends to be insufficient. As a result, there has been a problem that the refrigerant containing the liquid cannot be uniformly sent to each flat tube.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a heat exchanger capable of preventing refrigerant flow in a plurality of flat tubes arranged above and below, and an air conditioner including the heat exchanger. Is to provide.

The first invention, a plurality of refrigerant containing liquid header collecting pipe of the tubular to be guided upward and (40), is inserted into is arranged vertically so as to face each other physician the header manifold (40) And the inner peripheral surface of the peripheral wall portion (41) of the header collecting pipe (40) is curved toward the flat pipe (31) side so as to be flattened. It is constituted by an insertion surface (42) through which the pipe (31) is inserted and an opposing surface (43,4 4) facing the insertion surface (42). With reference to a line segment X connecting two connection points between the insertion surface (42) and the opposing surface (43,4 4) , the line segment X to the opposing surface (43,4 4) The maximum length between them is shorter than the maximum length between the line segment X and the insertion surface (42), and the open end (31a) of the flat tube (31) is formed flat, Face (43 , 44) is characterized by bulging on the opposite side of the flat tube (31) so that the maximum length from the line segment X to the opposing surface (43, 44) is greater than zero. To do.

In the first invention, the entire inner peripheral surface of the peripheral wall portion (41) of the header collecting pipe (40) is constituted by the insertion surface (42) and the opposing surface (43,4 4) . In the header collecting pipe (40), the flat pipe (31) is inserted through the insertion surface (42), and the opposing surfaces (43,4 ) are formed facing the insertion surface (42). In the present invention, in the cross section perpendicular to the axis of the peripheral wall portion (41) of the header collecting pipe (40), the line segment X connecting the connection points of the insertion surface (42) and the opposing surface (43,4 4) is used as a reference. Furthermore, the maximum length from the line segment X to the opposing surface (43,4 4) is shorter than the maximum length from the line segment X to the insertion surface (42). That is, in the header collecting pipe (40), the distance from the open end of the flat pipe (31) to the opposing surface (43,4 4) is relatively short. For this reason, in this invention, the cross-sectional area of the flow path of the refrigerant | coolant formed between the opening end of a flat tube (31) and an opposing surface (43,4 4) becomes small. Therefore, in the header collecting pipe (40), the flow rate of the refrigerant increases. In this way, even when the flow rate of the refrigerant flowing through the header collecting pipe (40) is relatively small, the flow rate of the refrigerant can be sufficiently ensured. Thereby, in the header collecting pipe (40), the liquid refrigerant can be sent up against its own weight. As a result, in the heat exchanger (30), the refrigerant drift in each of the flat tubes (31) arranged vertically is suppressed.

  In the header collecting pipe (40) of the present invention, the distance from the line segment X to the insertion surface (42) is relatively long. If it carries out like this, in the surrounding wall part (41) of a header collecting pipe (40), the shape by the side of the insertion surface (42) can be approximated to a perfect circle shape. Thereby, the pressure strength of the header collecting pipe (40) is improved.

  According to a second aspect, in the first aspect, the facing surface (44) is formed in an elliptical arc shape having the line segment X as a major axis.

  In the second invention, the opposing surface (44) of the header collecting pipe (40) is formed in an elliptical arc shape with the line segment X as the long axis in the cross section perpendicular to the axis of the header collecting pipe (40). Thereby, the distance from a flat tube (31) to an opposing surface (44) becomes short, and the flow velocity of the refrigerant | coolant which flows between an opposing surface (44) and a flat tube (31) increases.

  According to a third invention, in the first invention, the opposing surface (43) includes two regular arc-shaped small-diameter arc portions (43a) each continuous with the insertion surface (42), and the small-diameter arc portion (43a). ) And a large-diameter arc portion (43b) having a regular arc shape formed between the two small-diameter arc portions (43a) having an arc radius longer than the arc radius of .

  In the third invention, the opposing surface (43) of the header collecting pipe (40) has a pair of small-diameter arc portions (43a) and small-diameter arc portions (43a) in the cross section perpendicular to the axis of the header collecting pipe (40). ) Between the large-diameter arc portions (43b). Thereby, the distance from the flat tube (31) to the large-diameter arc portion (43b) is shortened, and the flow velocity of the refrigerant flowing between the facing surface (43) and the flat tube (31) is increased.

According to a fourth invention, in any one of the first to third inventions, the insertion surface (42) is formed in a regular arc shape or an elliptic arc shape.

In the fourth invention, the insertion surface (42) is formed in a regular arc shape or an elliptic arc shape in the cross section perpendicular to the axis of the header collecting pipe (40). As a result, the pressure resistance of the header collecting pipe (40) is improved.

A fifth invention is directed to an air conditioner and includes a refrigerant circuit (15) provided with the heat exchanger (30) according to any one of the first to fourth inventions, and the refrigerant circuit (15) A refrigeration cycle is performed by circulating a refrigerant.

In 5th invention, in the heat exchanger (30) of an air conditioner, the refrigerant | coolant which flows through a flat tube (31), and the air which flows through the ventilation path between each flat tube (31) heat-exchange.

In the present invention, since the distance from the line segment X to the opposing surface (43,4 4) is relatively short inside the header collecting pipe (40), the flat tube (31) and the opposing surface (43,4) are arranged. 4) The flow rate of the refrigerant flowing between can be increased. As a result, the liquid refrigerant can be sent to above the header collecting pipe (40) even under a condition where the circulation amount of the refrigerant is relatively small. Therefore, the drift of the liquid refrigerant in each flat tube (31) can be prevented. As a result, since the liquid refrigerant can be evenly supplied to each flat tube (31), the efficiency of the heat exchanger (30) can be improved.

  Further, in the present invention, the insertion surface (42) can be made closer to a perfect circle by relatively increasing the distance from the line segment X to the insertion surface (42) inside the header collecting pipe (40). The pressure-resistant strength of the header collecting pipe (40) can be secured. Thereby, deformation of the header collecting pipe (40) due to the internal pressure of the refrigerant can be prevented, and the fatigue life of the header collecting pipe (40) can be sufficiently secured.

In particular, in the second to fourth inventions, the insertion surface (42) and the opposing surface (43,4 4) continue relatively smoothly, so that stress concentration at such a continuous portion can be reduced, and the header collecting pipe ( 40) Withstand pressure strength can be improved. In addition, when the opposing surface (44) has an elliptical arc shape as in the second aspect of the invention, the design parameters of the opposing surface (44) are reduced as compared with, for example, the case where three arc portions are formed on the opposing surface. Therefore, in the second invention, the size management of the header collecting pipe (40) is facilitated, and the processing of the header collecting pipe (40) is facilitated.

  In the fifth invention, the pressure resistance strength of the header collecting pipe (40) is further improved by forming the insertion surface (42) in a regular arc shape or an elliptical arc shape.

FIG. 1 is a schematic piping diagram of the air conditioner according to the first embodiment. FIG. 2 is an elevation view of the heat exchanger according to the first embodiment. FIG. 3 is an enlarged view of flat tubes and fins of the heat exchanger according to the first embodiment. 4 is a cross-sectional view taken along the line IV-IV in FIG. 5 is a cross-sectional view taken along the line V-V in FIG. FIG. 6 is a view corresponding to FIG. 5 showing the dimensional relationship of the first header collecting pipe. FIG. 7 is a horizontal sectional view of the header collecting pipe of the heat exchanger to be compared. FIG. 8 shows the relationship between the refrigerant circulation rate and the diversion rate for the heat exchanger according to the first embodiment and the heat exchanger to be compared. FIG. 9 is a cross-sectional view perpendicular to the axis of the first header collecting pipe of the heat exchanger according to the first modification of the first embodiment. FIG. 10 is a view corresponding to FIG. 9 showing the dimensional relationship of the first header collecting pipe. FIG. 11 is a cross-sectional view perpendicular to the axis of the first header collecting pipe of the heat exchanger according to the reference example . FIG. 12 is a view corresponding to FIG. 11 showing the dimensional relationship of the first header collecting pipe. FIG. 13 is an elevation view of the heat exchanger according to the second embodiment. FIG. 14 is an elevation view of the heat exchanger according to the third embodiment. FIG. 15 is a longitudinal sectional view of a heat exchanger according to the third embodiment. FIG. 16 is an elevation view of the heat exchanger according to the fourth embodiment. FIG. 17 is a longitudinal sectional view of a heat exchanger according to the fourth embodiment. FIG. 18 is an elevation view of the heat exchanger according to the fifth embodiment. FIG. 19 is a longitudinal sectional view of a heat exchanger according to the fifth embodiment. FIG. 20 is an enlarged view of flat tubes and fins of a heat exchanger according to another embodiment. FIG. 21 is a cross-sectional view taken along line XVII-XVII in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 of the Invention
A first embodiment of the present invention will be described. The heat exchanger of the present embodiment constitutes an outdoor heat exchanger (30) of an air conditioner (10) described later.

-Air conditioner-
The air conditioner (10) provided with the heat exchanger of the present embodiment will be described with reference to FIG.

<Configuration of air conditioner>
The air conditioner (10) includes an outdoor unit (11) and an indoor unit (12). The outdoor unit (11) and the indoor unit (12) are connected to each other via a liquid side connecting pipe (13) and a gas side connecting pipe (14). In the air conditioner (10), a refrigerant circuit (15) is formed by the outdoor unit (11), the indoor unit (12), the liquid side communication pipe (13), and the gas side communication pipe (14).

  The refrigerant circuit (15) is provided with a compressor (16), a four-way switching valve (17), an outdoor heat exchanger (30), an expansion valve (18), and an indoor heat exchanger (19). ing. The compressor (16), the four-way switching valve (17), the outdoor heat exchanger (30), and the expansion valve (18) are accommodated in the outdoor unit (11). The outdoor unit (11) is provided with an outdoor fan (20) for supplying outdoor air to the outdoor heat exchanger (30). On the other hand, the indoor heat exchanger (19) is accommodated in the indoor unit (12). The indoor unit (12) is provided with an indoor fan (21) for supplying room air to the indoor heat exchanger (19).

  The refrigerant circuit (15) is a closed circuit filled with a refrigerant. In the refrigerant circuit (15), the compressor (16) has its discharge side connected to the first port of the four-way switching valve (17) and its suction side connected to the second port of the four-way switching valve (17). Yes. In the refrigerant circuit (15), the outdoor heat exchanger (30), the expansion valve (18), and the indoor heat exchanger are sequentially arranged from the third port to the fourth port of the four-way switching valve (17). (19) and are arranged.

  The compressor (16) is a scroll type or rotary type hermetic compressor. The four-way switching valve (17) includes a first state (state indicated by a solid line in FIG. 1) in which the first port communicates with the third port and the second port communicates with the fourth port; The port is switched to a second state (state indicated by a broken line in FIG. 1) in which the port communicates with the fourth port and the second port communicates with the third port. The expansion valve (18) is a so-called electronic expansion valve.

  The outdoor heat exchanger (30) exchanges heat between the outdoor air and the refrigerant. The outdoor heat exchanger (30) is configured by a plurality (for example, three) of the heat exchangers of the present embodiment. In the outdoor heat exchanger (30), a plurality of heat exchangers of the present embodiment are connected in parallel to each other. On the other hand, the indoor heat exchanger (19) exchanges heat between the indoor air and the refrigerant. The indoor heat exchanger (19) may be configured by the heat exchanger of the present embodiment, or may be configured by a so-called cross fin type heat exchanger including a heat transfer tube that is a circular tube.

<Cooling operation>
The air conditioner (10) performs a cooling operation. During the cooling operation, the four-way switching valve (17) is set to the first state. During the cooling operation, the outdoor fan (20) and the indoor fan (21) are operated.

  In the refrigerant circuit (15), a refrigeration cycle is performed. Specifically, the refrigerant discharged from the compressor (16) flows into the outdoor heat exchanger (30) through the four-way switching valve (17), dissipates heat to the outdoor air, and is condensed. The refrigerant flowing out of the outdoor heat exchanger (30) expands when passing through the expansion valve (18), then flows into the indoor heat exchanger (19), absorbs heat from the indoor air, and evaporates. The refrigerant that has flowed out of the indoor heat exchanger (19) passes through the four-way switching valve (17) and then is sucked into the compressor (16) and compressed. The indoor unit (12) supplies the air cooled in the indoor heat exchanger (19) to the room.

<Heating operation>
The air conditioner (10) performs heating operation. During the heating operation, the four-way selector valve (17) is set to the second state. During the heating operation, the outdoor fan (20) and the indoor fan (21) are operated.

  In the refrigerant circuit (15), a refrigeration cycle is performed. Specifically, the refrigerant discharged from the compressor (16) flows into the indoor heat exchanger (19) through the four-way switching valve (17), dissipates heat to the indoor air, and condenses. The refrigerant flowing out of the indoor heat exchanger (19) expands when passing through the expansion valve (18), then flows into the outdoor heat exchanger (30), absorbs heat from the outdoor air, and evaporates. The refrigerant that has flowed out of the outdoor heat exchanger (30) passes through the four-way switching valve (17) and then is sucked into the compressor (16) and compressed. And an indoor unit (12) supplies the air heated in the indoor heat exchanger (19) indoors.

<Defrosting operation>
As described above, the outdoor heat exchanger (30) functions as an evaporator during the heating operation. Under operating conditions where the outside air temperature is low, the evaporation temperature of the refrigerant in the outdoor heat exchanger (30) may be lower than 0 ° C. In this case, moisture in the outdoor air becomes frost and the outdoor heat exchanger (30 ). Therefore, the air conditioner (10) performs the defrosting operation every time the duration time of the heating operation reaches a predetermined value (for example, several tens of minutes).

  When the defrosting operation is started, the four-way switching valve (17) is switched from the second state to the first state, and the outdoor fan (20) and the indoor fan (21) are stopped. In the refrigerant circuit (15) during the defrosting operation, the high-temperature refrigerant discharged from the compressor (16) is supplied to the outdoor heat exchanger (30). In the outdoor heat exchanger (30), the frost adhering to the surface is heated and melted by the refrigerant. The refrigerant that has radiated heat in the outdoor heat exchanger (30) sequentially passes through the expansion valve (18) and the indoor heat exchanger (19), and then is sucked into the compressor (16) and compressed. Then, when the defrosting operation is completed, the heating operation is resumed. That is, the four-way switching valve (17) is switched from the first state to the second state, and the operation of the outdoor fan (20) and the indoor fan (21) is resumed.

-Heat exchanger of Embodiment 1-
The heat exchanger of this embodiment which comprises the outdoor heat exchanger (30) of an air conditioner (10) is demonstrated, referring FIGS. 2-6 suitably.

<Overall heat exchanger configuration>
As shown in FIG. 2, the outdoor heat exchanger (30) of the present embodiment includes one first header collecting pipe (40), one second header collecting pipe (50), and a large number of flat tubes (31 ) And a large number of fins (35). The first header collecting pipe (40), the second header collecting pipe (50), the flat pipe (31), and the fin (35) are all made of an aluminum alloy and are joined to each other by brazing. .

  The first header collecting pipe (40) and the second header collecting pipe (50) are formed in a hollow and elongated tubular shape. In the outdoor heat exchanger (30), the first header collecting pipe (40) is erected on one end side of the flat pipe (31), and the second header collecting pipe (50) is arranged on the other end side of the flat pipe (31). It is erected. That is, the first header collecting pipe (40) and the second header collecting pipe (50) extend vertically so that the respective axial directions are vertical.

The upper end portion of the first header collecting pipe (40) is closed by the first closing portion (40a). The first connecting pipe (40b) is connected to the lower end of the first header collecting pipe (40). The first connecting pipe (40b) communicates with the liquid line (line on the expansion valve (18) side) of the refrigerant circuit (15). That is, the first header collecting pipe (40) constitutes a liquid-side header through which a liquid-containing refrigerant (liquid single-phase refrigerant or gas-liquid two-phase refrigerant) flows. The upper end and the lower end of the second header collecting pipe (50) are closed by the second closing part (50a). A second connection pipe (50b) is connected to the upper part of the second header collecting pipe (50). The second connecting pipe (50b) is connected to the gas line (third port side line) of the refrigerant circuit (15). That is, the 2nd header collecting pipe (50) comprises the gas side header into which a gas refrigerant flows. The outdoor heat exchanger (30) of this embodiment has a plurality of flat tubes (31). The flat tube (31) is a heat transfer tube whose cross-sectional shape perpendicular to the axis is a flat oval or rectangular shape. In the outdoor heat exchanger (30), the plurality of flat tubes (31) are arranged in a posture in which the extending direction is the left-right direction and the flat side surfaces face each other. The plurality of flat tubes (31) are arranged side by side at regular intervals. Each flat tube (31) has one end inserted into the first header collecting tube (40) and the other end inserted into the second header collecting tube (50).

  As shown in FIG. 3, a plurality of refrigerant passages (32) are formed in each flat tube (31). Each refrigerant passage (32) is a passage extending in the extending direction of the flat tube (31). In each flat tube (31), the plurality of refrigerant passages (32) are arranged in a line in the width direction orthogonal to the extending direction of the flat tube (31). The refrigerant passage (32) of each flat tube (31) has one end communicating with the internal space of the first header collecting pipe (40) and the other end communicating with the internal space of the second header collecting pipe (50). Yes.

  A fin (35) is a corrugated fin meandering up and down, and is arrange | positioned between the flat pipes (31) adjacent up and down. The fin (35) has a plurality of heat transfer portions (36) arranged in the extending direction of the flat tube (31). The heat transfer section (36) is formed in a plate shape extending from one side of the adjacent flat tube (31) to the other. The heat transfer section (36) is provided with a plurality of louvers (37) formed by cutting and raising a part of the heat transfer section (36). These louvers (37) extend vertically so as to be substantially parallel to the front edge (that is, the windward end) of the heat transfer section (36). In the heat transfer section (36), the louvers (37) are formed side by side from the windward side toward the leeward side.

  A projecting plate portion (38) projecting further to the leeward side is connected to the leeward side end of the heat transfer portion (36). The projecting plate portion (38) is formed in a trapezoidal plate shape that projects above and below the heat transfer portion (36). In the outdoor heat exchanger (30), the protruding plate portions (38, 38) adjacent to each other in the vertical direction overlap in the thickness direction and are substantially in contact with each other.

<Detailed structure of header collecting pipe>
As shown in FIG. 4, the axially perpendicular cross-sectional shape of the peripheral wall portion (51) of the second header collecting pipe (50) is a perfect circle shape. The thickness of the peripheral wall portion (51) of the second header collecting pipe (50) is substantially uniform over the entire circumference. A plurality of second header side connection ports (52) through which the end portions of the respective flat tubes (31) are inserted are formed in the peripheral wall portion (51) of the second header collecting pipe (50). The plurality of second header side connection ports (52) are arranged in the vertical direction at regular intervals. The flat tube (31) is fixed to the second header collecting pipe (50) so that the opening end (31a) is positioned slightly in front of the axis of the second header collecting pipe (50).

  As shown in FIG. 5, the cross-sectional shape perpendicular to the axis of the peripheral wall portion (41) of the first header collecting pipe (40) is D-shaped. The thickness of the peripheral wall portion (41) of the first header collecting pipe (40) is substantially uniform over the entire circumference. The thickness of the peripheral wall portion (41) of the first header collecting pipe (40) is larger than the thickness of the peripheral wall portion (51) of the second header collecting pipe (50).

  The entire inner peripheral surface of the peripheral wall portion (41) of the first header collecting pipe (40) is constituted by an insertion surface (42) and an opposing surface (43).

  The insertion surface (42) is formed in a curved shape that bulges outward in the radial direction so as to curve toward the flat tube (31) side in the cross section perpendicular to the axis of the first header collecting tube (40). In the insertion surface (42), an insertion port (42a) of the flat tube (31) is formed at an intermediate portion in the width direction of the flat tube (31). The flat tube (31) penetrates the peripheral wall (41) so that the open end (31a) is located inside the insertion surface (42). The insertion surface (42) has a substantially symmetrical shape in the width direction of the flat tube (31). Specifically, the insertion surface (42) is formed so that the shape of the cross section perpendicular to the axis of the first header collecting pipe (40) is a regular arc shape (more specifically, a regular semicircular shape) having an arc radius of R1. Yes.

  The opposing surface (43) is disposed to face the insertion surface (42) so as to be continuous with the insertion surface (42). Thereby, the opposing surface (43) is opposed to the open end (31a) of the flat tube (31). The opposing surface (43) of Embodiment 1 is formed between a pair of small-diameter arc portions (43a, 43a) continuous with the insertion surface (42) and the pair of small-diameter arc portions (43a, 43a). And a radial arc portion (43b). The small-diameter arc portion (43a) is formed in a regular arc shape in which the shape of the cross section perpendicular to the axis of the first header collecting pipe (40) has an arc radius of R2. The large-diameter arc portion (43b) is formed in a regular arc shape in which the shape of the cross section perpendicular to the axis of the first header collecting pipe (40) has an arc radius of R3.

<Detailed dimensions of the first header collecting pipe>
As shown in FIG. 5, in the first header collecting pipe (40) of the first embodiment, the arc radius R3 of the large-diameter arc portion (43b) of the facing surface (43) is larger than the arc radius R1 of the insertion surface (42). Is also getting bigger. That is, the large-diameter arc portion (43b) of the facing surface (43) has a substantially flat shape with a larger radius of curvature than the insertion surface (42). The arc radius R2 of the small-diameter arc portion (43a, 43a) of the opposing surface (43) is smaller than both the arc radius R3 of the large-diameter arc portion (43b) and the arc radius R1 of the insertion surface (42). ing.

  As shown in FIG. 6, in the first header collecting pipe (40), the length L1 is shorter than the length L2. Here, L1 is the maximum length from the line segment X to the opposing surface (43) (large-diameter arc part (43b)), and more specifically, the center point (middle point M) of the line segment X in the width direction. ) To the opposing surface (43). L2 is the maximum length from the line segment X to the insertion surface (42), and more specifically, the length of the perpendicular from the midpoint M to the insertion surface (42). The line segment X is a straight line connecting two connection points (c1, c2) between the insertion surface (42) and the opposing surface (43) in the cross section perpendicular to the axis of the first header collecting pipe (40). is there. These two connection points (c1, c2) are shared between the insertion surface (42) and the opposing surface (43) (more specifically, the insertion surface (42) and a pair of small-diameter arc portions (43a, 43a)). It can be said that it is a contact point on the tangent line. The line segment X can also be said to be a line segment that forms the width (maximum width Dmax) of the widest space in the width direction of the flat tube (31) inside the peripheral wall (41) of the first header collecting pipe (40). Further, the line segment X forms a chord of the insertion surface (42) having a semi-circular arc shape.

  In Embodiment 1, the ratio of L1 to L2 (L1 / L2) is preferably 0.05 or more and 0.35 or less. In the first embodiment, when the arc radius of the insertion surface (42) is D / 2 (arc diameter D), the ratio (R2 / D) of the arc radius R2 of the small-diameter arc portion (43a) to the arc diameter D Is preferably 0.05 or more and 0.2 or less. Furthermore, in Embodiment 1, when the thickness of the peripheral wall portion (41) of the first header collecting pipe (40) is t, the ratio (t / D) of the thickness t to the arc diameter D of the insertion surface (42). Is preferably 0.05 or more and 0.20 or less.

<Flow of refrigerant in outdoor heat exchanger>
During the cooling operation described above, the outdoor heat exchanger (30) functions as a condenser. As shown by the solid arrows in FIG. 2, during the cooling operation, the high-pressure gas refrigerant compressed by the compressor (16) flows into the second header collecting pipe (50) through the second connecting pipe (50b). To do. In the second header collecting pipe (50), the gas refrigerant flows into the respective flat pipes (31) while flowing downward. The refrigerant flowing through each flat tube (31) dissipates heat to the outdoor air and condenses. The condensed liquid refrigerant flows downward while joining in the first header collecting pipe (40). The merged liquid refrigerant is sent to the expansion valve (18) side through the first connection pipe (40b).

  During the heating operation described above, the outdoor heat exchanger (30) functions as an evaporator. As indicated by the broken line arrow in FIG. 2, during the heating operation, the liquid refrigerant condensed in the indoor heat exchanger (19) and decompressed by the expansion valve (18) passes through the first connection pipe (40b). 1 flows into the header collecting pipe (40). In the first header collecting pipe (40), the refrigerant containing the liquid is divided into each flat pipe (31) while flowing upward. The refrigerant flowing through each flat tube (31) absorbs heat from the outdoor air and evaporates. The evaporated gas refrigerant flows upward while joining in the second header collecting pipe (50). The merged gas refrigerant is sent to the suction side of the compressor (16) through the second connection pipe (50b).

<Inhibition of refrigerant drift>
During the heating operation, a refrigerant containing a relatively high density liquid refrigerant flows upward through the first header collecting pipe (40). At this time, in the first header collecting pipe (40) of the present embodiment, the drift of the refrigerant in each flat pipe (31) can be suppressed. The result of examining this point will be described with reference to the graph of FIG.

  FIG. 8 shows the circulation amount of the refrigerant and the flat tube (31) when the refrigerant is sent from the lower end of the first header collecting pipe (40) and the refrigerant is divided into each flat pipe (31) during the heating operation. It shows the relationship with the diversion degree. A solid line L in FIG. 8 indicates the relationship between the refrigerant circulation rate and the diversion rate in the outdoor heat exchanger (30) according to the present embodiment (first header collecting pipe (40) shown in FIG. 5). On the other hand, the broken line M in FIG. 8 shows the relationship between the refrigerant circulation rate and the diversion rate in the outdoor heat exchanger (header collecting pipe (140) shown in FIG. 7) to be compared. Note that the peripheral wall portion (141) of the header collecting pipe (140) to be compared has a D-shaped cross section perpendicular to the axis, similar to the peripheral wall section (41) of the first header collecting pipe (40) of the present embodiment. Is formed. On the other hand, in this header collecting pipe (140), the insertion surface (142) is formed in a substantially flat shape, and the opposing surface (143) is formed in a semi-regular arc shape. An insertion port (142a) for the flat tube (131) is formed on the insertion surface (142).

  Further, the “diversion degree” shown in FIG. 8 is calculated by the following equation (1).

  In the above formula (1), n is the number of flat tubes (31), and Li is the arrival length of the two-phase refrigerant in the i-th flat tube (31). This reach length Li is the inflow end of the flat tube (31) when the point at which the refrigerant that has flowed into the flat tube (31) and changed to a gas-liquid two-phase state is changed to a single-phase gas refrigerant is point G. It means the length from to the point G. Lave is the average value of the reach length Li of the two-phase refrigerant for each flat tube (31). Formula (1) takes into account the degree of dispersion of Li in each flat tube (31) with respect to the average value Lave. The closer to 1 the diversion degree φ determined by equation (1), the more uniform the amount of refrigerant diverted to each flat tube (31).

  In the outdoor heat exchanger (30) to be compared indicated by the broken line M, the diversion rate φ is extremely reduced in the operation range where the refrigerant circulation amount is relatively small, and this diversion rate φ is the lowest diversion rate indicated by the S line in FIG. (Minimum diversion degree necessary for ensuring the performance of the heat exchanger). This is because when the refrigerant flows upward in the header collecting pipe (140), the refrigerant circulation amount is relatively small, so the flow rate of the refrigerant is reduced, and the liquid refrigerant cannot be sent upward against its own weight, Accordingly, it can be assumed that the liquid refrigerant cannot be sufficiently supplied to the upper flat tube (31).

  On the other hand, in the outdoor heat exchanger (30) of the present embodiment indicated by the solid line L, the diversion degree φ exceeds the minimum diversion degree indicated by the S line even under operating conditions where the refrigerant circulation amount is relatively small. As shown in FIG. 6, in the first header collecting pipe (40) of this embodiment, the distance from the open end (31a) of the flat pipe (31) to the facing surface (43) is the one to be compared. It can be guessed that it is shorter than That is, when the distance from the open end (31a) to the facing surface (43) is shortened in this way, the cross-sectional area of the refrigerant flow path formed between the flat tube (31) and the facing surface (43) is reduced. it can. Then, in the first header collecting pipe (40), even under a condition where the refrigerant circulation amount is relatively small, the high-density liquid refrigerant can be sent up against its own weight. For this reason, in the outdoor heat exchanger (30) of this embodiment, it becomes easy to supply a liquid refrigerant also to the flat tube (31) near the upper side. As a result, in the outdoor heat exchanger (30), it is possible to suppress the drift of the refrigerant in the flat tubes (31) arranged vertically.

  In addition, in the first header collecting pipe (40), the shape of the facing surface (43) is formed to be flatter than the comparison target. For this reason, in this embodiment, the distance from the opening end (31a) to the opposing surface (43) is relatively uniform in the width direction of the flat tube (31). Here, strictly speaking, in the first header collecting pipe (40), a relatively high density liquid refrigerant flows near the outer periphery, and a relatively low density gas refrigerant flows near the axis. For this reason, the liquid refrigerant easily flows along the wall surface of the opposing surface (43) inside the first header collecting pipe (40). Therefore, when the distance from the open end (31a) of the flat tube (31) to the facing surface (43) is made uniform, the liquid refrigerant on the facing surface (43) side is allowed to flow into a plurality of refrigerant passages in the flat tube (31) ( 32, 32, ...) evenly. That is, in this embodiment, the drift of the refrigerant in each refrigerant channel (32) in the flat tube (31) can also be prevented.

-Effect of Embodiment 1-
According to Embodiment 1, as shown in FIG. 6, the maximum length L1 from the line segment X to the facing surface (43) is made shorter than the maximum length L2 from the line segment X to the insertion surface (42). Therefore, the flow rate of the refrigerant flowing between the facing surface (43) and the flat tube (31) can be improved. As a result, refrigerant drift in the upper and lower flat tubes (31) can be prevented, and the efficiency of heat exchange in the outdoor heat exchanger (30) can be increased. Therefore, the heating capacity of the air conditioner (10) can be improved.

  Further, as shown in FIG. 6, the maximum length L2 from the line segment X to the insertion surface (42) is made relatively long, and the shape of the insertion surface (42) is formed in a semi-circular arc shape. The pressure resistance of the header collecting pipe (40) can be improved. Moreover, since the insertion surface (42) continues smoothly with each small circular arc part (43a, 43a) of an opposing surface (43), the stress concentration in such a continuous site | part can also be relieve | moderated. Therefore, in the present embodiment, the first header collecting pipe (40) can be prevented from being deformed by the pressure of the high-pressure refrigerant, and the pressure-resistant life of the first header collecting pipe (40) can be sufficiently secured.

  Furthermore, in this embodiment, since the distance from the open end (31a) of the flat tube (31) to the facing surface (43) is also made uniform, the liquid refrigerant on the facing surface (43) side is transferred to the flat tube (31). To each refrigerant passage (32). As a result, the drift of the refrigerant in each refrigerant passage (32) can be prevented, and the efficiency of heat exchange of the outdoor heat exchanger (30) can be increased. Further, since the open end (31a) of the flat tube (31) and the facing surface (43) are unlikely to interfere with each other, the insertion allowance of the flat tube (31) can be sufficiently secured.

<Modification of Embodiment 1>
The first header collecting pipe (40) of the first embodiment may be configured as the following modifications.

-Modification 1-
The first header collecting pipe (40) according to Modification 1 will be described with reference to FIGS.

  The entire inner peripheral surface of the peripheral wall portion (41) of the first header collecting pipe (40) according to Modification 1 is constituted by an insertion surface (42) and an opposing surface (44). The insertion surface (42) according to Modification 1 has a configuration that is substantially the same as that of the first embodiment. The opposing surface (44) of Modification 1 has an elliptical arc shape in the shape of a cross section perpendicular to the axis of the first header collecting pipe (40). The major axis of the facing surface (44) is substantially parallel to the open end (31a) of the flat tube (31), and the minor axis of the facing surface (44) is coaxial with the intermediate line in the width direction of the flat tube (31). It has become.

  As shown in FIG. 10, in the first header collecting pipe (40) of Modification 1, the length L1 is shorter than the length L2. Here, L1 is the maximum length from the line segment X to the opposing surface (44), and more specifically, from the center point (middle point M) in the width direction of the line segment X to the opposing surface (44). The length of the perpendicular. L2 is the maximum length from the line segment X to the insertion surface (42), and more specifically, the length of the perpendicular from the midpoint M to the insertion surface (42). The line segment X is a straight line connecting two connection points (C1, C2) between the insertion surface (42) and the opposing surface (44) in the cross section perpendicular to the axis of the first header collecting pipe (40). is there. These two connection points (C1, C2) can be said to be contact points on a tangent line shared by the insertion surface (42) and the opposing surface (44). The line segment X can also be said to be a line segment that forms the width (maximum width Dmax) of the widest space in the width direction of the flat tube (31) inside the peripheral wall (41) of the first header collecting pipe (40). Further, the line segment X forms a chord of a semi-circular arc-shaped insertion surface (42) and a long axis of the semi-elliptical opposing surface (44).

  In the first modification, the ratio (2 × L1) of the short axis diameter (ie, 2 × L1) of the facing surface (44) to the length of the line segment X (the major axis diameter D = 2 × a of the facing surface (44)). / D) is preferably 0.05 or more and 0.45 or less. In the first modification, the ratio of the short axis diameter (that is, 2 × L2) of the insertion surface (42) to the length of the line segment X (the long axis diameter D = 2 × a of the facing surface (44)) (2 XL2 / D) is preferably 0.5 or more and 0.1 or less. Further, in Modification 1, when the thickness of the peripheral wall portion (41) of the first header collecting pipe (40) is t, the ratio of the thickness t to the arc diameter D of the insertion surface (42) (t / D) Is preferably 0.05 or more and 0.2 or less.

-Effect of Modification 1-
In Modification 1, the distance L1 from the open end (31a) of the flat tube (31) to the facing surface (44) can be shortened by making the facing surface (44) elliptical. Therefore, the flow velocity of the refrigerant flowing between the flat tube (31) and the facing surface (44) can be increased, and the refrigerant flow in the upper and lower flat tubes (31) can be prevented. On the other hand, the insertion surface (42) is formed in a semi-circular arc shape as in the first embodiment, so that the pressure resistance of the first header collecting pipe (40) can be sufficiently secured.

  Further, the shape of the opposing surface (44) of Modification 1 is determined by the radius a on the major axis side and the radius b on the minor axis side. For this reason, for example, the design parameters are reduced as compared with those having three arc portions (43a, 43a, 43b) as in the first embodiment. Therefore, in the first modification, the size management and processing of the facing surface (44) are relatively easy.

  Furthermore, the opposing surface (44) of Modification 1 shown in FIG. 9 is flatter than the opposing surface (143) to be compared shown in FIG. For this reason, the liquid refrigerant by the side of a counter surface (44) can be equally sent to each refrigerant path (32) in a flat tube (31).

-Reference example-
The first header collecting pipe (40) according to the reference example will be described with reference to FIGS.

The entire inner peripheral surface of the peripheral wall portion (41) of the first header collecting pipe (40) according to the reference example is composed of an insertion surface (42) and an opposing surface (45). The insertion surface (42) according to the reference example has substantially the same configuration as that of the first embodiment. The facing surface (45) of the reference example is formed by a pair of arc portions (45a, 45a) continuous with the insertion surface (42) and a plane portion (45b) formed between the pair of arc portions (45a, 45a). And is composed of. The arc portion (45a) is formed in a regular arc shape in which the shape of the cross section perpendicular to the axis of the first header collecting pipe (40) has an arc radius of R4. The flat portion (45b) is formed in a straight line shape in which the cross section perpendicular to the axis of the first header collecting pipe (40) is substantially parallel to the open end (31a) of the flat pipe (31).

As shown in FIG. 11, in the first header collecting pipe (40) of the reference example , the arc radius R4 of the arc portion (45a) of the facing surface (45) is smaller than the arc radius R1 of the insertion surface (42). ing.

As shown in FIG. 12, in the first header collecting pipe (40) of the reference example , the length L1 is shorter than the length L2. Here, L1 is the maximum length from the line segment X to the facing surface (45), and more specifically, from the center point (middle point M) in the width direction of the line segment X to the facing surface (45). The length of the perpendicular. L2 is the maximum length from the line segment X to the insertion surface (42), and more specifically, the length of the perpendicular from the midpoint M to the insertion surface (42). The line segment X is a straight line connecting two connection points (C1, C2) between the insertion surface (42) and the opposing surface (45) in the cross section perpendicular to the axis of the first header collecting pipe (40). is there. These two connection points (C1, C2) are shared by the insertion surface (42) and the opposing surface (45) (more specifically, the insertion surface (42) and the pair of arc portions (45a, 45a)). It can also be said to be a contact point on the tangent line The line segment X can also be said to be a line segment that forms the width (maximum width Dmax) of the widest space in the width direction of the flat tube (31) inside the peripheral wall (41) of the first header collecting pipe (40). Further, the line segment X forms a chord of the insertion surface (42) having a semi-circular arc shape.

In the reference example , when the arc diameter of the insertion surface (42) is D and the interval in the insertion direction of the flat tube (31) in the peripheral wall (41) is L1 + L2, the ratio of the interval (L1 + L2) to the arc diameter D (ie, , (L1 + L2) / D) is preferably 0.3 or more and 0.6 or less. Furthermore, in the reference example , the ratio (R4 / D) of the arc radius R4 of the arc portion (45a) of the facing surface (45) to the arc diameter D of the insertion surface (42) is 0.05 or more and 0.2 or less. It is preferable. Furthermore, in the reference example , the ratio (t / D) of the wall thickness t of the peripheral wall portion (41) to the arc diameter D of the insertion surface (42) is preferably 0.05 or more and 0.2 or less.

-Effect of reference example-
In the reference example , the opposed surface (45) is composed of a pair of arc portions (45a, 45a) and a flat surface portion (45b), so that the open end (31a) of the flat tube (31) to the opposed surface (45) The distance L1 can be shortened. Therefore, the flow velocity of the refrigerant flowing between the flat tube (31) and the facing surface (45) can be increased, and the refrigerant flow in the upper and lower flat tubes (31) can be prevented. On the other hand, the insertion surface (42) is formed in a semi-circular arc shape as in the first embodiment, so that the pressure resistance of the first header collecting pipe (40) can be sufficiently secured.

Moreover, since the opposing surface (45) of a reference example continues smoothly with the insertion surface (42) via a circular arc part (45a, 45a), the stress concentration in such a continuous part can also be relieved.

Further, the flat portion (45b) of the facing surface (45) of the reference example shown in FIG. 12 has a flatter shape than the facing surface (143) of the comparison target shown in FIG. For this reason, the liquid refrigerant by the side of an opposing surface (45) can be equally sent to each refrigerant path (32) in a flat tube (31).

-Other variations-
In the first embodiment and each modified example, the insertion surface (42) is formed in a semicircular arc shape, but may be a regular arc shape having an arc angle smaller than the semicircle, for example, a line segment X The major axis may be an elliptical arc shape. Further, the insertion surface (42) may be constituted by a plurality of arc portions having different arc angles.

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described. The second embodiment is different from the first embodiment in the configuration of the outdoor heat exchanger (30).

  As shown in FIG. 13, the outdoor heat exchanger (30) of Embodiment 2 constitutes a so-called return type heat exchanger. Specifically, in the first header collecting pipe (40) of the second embodiment, both the upper end portion and the lower end portion are covered with the first closing portion (40a). Moreover, as for the 2nd header collecting pipe (50) of Embodiment 2, both an upper end part and a lower end part are covered with the 2nd obstruction | occlusion part (50a). The first connecting pipe (40b) is connected to the lower part of the second header collecting pipe (50). The first connecting pipe (40b) communicates with the liquid line (line on the expansion valve (18) side) of the refrigerant circuit (15). As in the first embodiment, the second connection pipe (50b) is connected to the upper part of the second header collecting pipe (50).

  In the second header collecting pipe (50) of the second embodiment, an upper partition plate (61) and a lower partition plate (62) are provided near the lower portion thereof. The upper partition plate (61) and the lower partition plate (62) partition the internal space of the second header collecting pipe (50) vertically. Thereby, the inside of the second header collecting pipe (50) includes the gas side space (63) above the upper partition plate (61) and the liquid side space (64) below the lower partition plate (62). And an ineffective space (65) between the partition plates (61, 62). The gas side space (63) is connected to the second connection pipe (50b), and the liquid side space (64) is connected to the first connection pipe (40b). The invalid space (65) is cut off from both connecting pipes (40b, 50b).

  The plurality of flat tubes (31) of the second embodiment includes a plurality of upper flat tubes (66) directly connected to the gas side space (63) and a plurality of lower flat tubes connected directly to the liquid side space (64). It consists of a pipe (67) and one dummy flat pipe (68) directly connected to the invalid space (65). The number of lower flat tubes (67) is larger than the number of upper flat tubes (66). The dummy flat pipe (68) is a pipe through which substantially no refrigerant flows. The dummy flat tube (68) is disposed between the upper flat tube (66) and the lower flat tube (67), and suppresses heat exchange between the refrigerants flowing through the flat tubes (66, 67). .

  Specifically, in the second embodiment, during the heating operation, the liquid refrigerant condensed in the indoor heat exchanger (19) and depressurized by the expansion valve (18) is supplied to the second through the first connection pipe (40b). It flows into the liquid side space (64) of the header collecting pipe (50). The liquid refrigerant is divided into the lower flat pipe (67) and then flows through the first header collecting pipe (40). In the lower flat tube (67), the liquid refrigerant absorbs heat from the outdoor air and enters a gas-liquid two-phase state. This refrigerant is divided into the upper flat pipe (66) while flowing upward through the first header collecting pipe (40).

  Also in the second embodiment, the first header collecting pipe (40) similar to that in the first embodiment and the modification described above is used. Thereby, a liquid refrigerant can be equally sent to each flat tube (31).

The refrigerant flowing through each upper flat tube (66) absorbs heat from the outdoor air and evaporates. The evaporated gas refrigerant joins in the gas side space (63) of the second header collecting pipe (50) and is sent to the suction side of the compressor (16) through the second connecting pipe (50b).
<< Embodiment 3 of the Invention >>
The outdoor heat exchanger of Embodiment 3 of invention is demonstrated. FIG. 14 is a front view illustrating a schematic configuration of the outdoor heat exchanger (30) of the third embodiment. FIG. 15 is a partial cross-sectional view showing the front of the outdoor heat exchanger (30) of the third embodiment.

  As shown in FIG. 14, the outdoor heat exchanger (30) is divided into three heat exchange units (350a to 350c). Specifically, the outdoor heat exchanger (30) includes a first heat exchange part (350a), a second heat exchange part (350b), and a third heat exchange part (350c) in order from bottom to top. And are formed.

  As shown in FIG. 15, each of the second header collecting pipe (50) and the first header collecting pipe (40) is divided into three communication spaces (361a to 361a) by partitioning the internal space with a partition plate (339). 361c, 371a-371c) are formed.

  The communication spaces (361a to 361c) of the second header collecting pipe (50) are further partitioned vertically by a partition plate (339). In each communication space (361a to 361c) of the second header collecting pipe (50), the lower space is the lower partial space (362a to 362c) which is the first partial space, and the upper space is the second partial space. A certain upper partial space (363a to 363c) is formed.

  Each heat exchange part (350a-350c) of the outdoor heat exchanger (30) has a main heat exchange area (351a-351c) (main heat exchange part) and an auxiliary heat exchange area (352a-352c) (auxiliary heat exchange part) It is divided into. In each heat exchange section (350a to 350c), eleven flat tubes (31) communicating with the upper partial spaces (363a to 363c) of the corresponding second header collecting pipe (50) are the main heat exchange sections (351a to 350c). 351c), and three flat tubes (31) communicating with the lower partial space (362a to 362c) of the corresponding second header collecting pipe (50) constitute the auxiliary heat exchange section (352a to 352c). However, the number of the flat tubes (31) communicating with the main heat exchange parts (351a to 351c) and the lower partial spaces (362a to 362c) is not limited to this.

  As shown in FIG. 14, the outdoor heat exchanger (30) is provided with a liquid side connection member (380) and a gas side header (385). The liquid side connection member (380) and the gas side header (385) are attached to the second header collecting pipe (50).

  The liquid side connection member (380) includes one shunt (381) and three small diameter tubes (382a to 382c). A pipe connecting the outdoor heat exchanger (30) and the expansion valve (18) is connected to the lower end of the flow divider (381). One end of each small diameter pipe (382a to 382c) is connected to the upper end of the flow divider (381). Inside the flow divider (381), the pipe connected to the lower end portion thereof and each small diameter pipe (382a to 382c) communicate with each other. The other end of each small-diameter pipe (382a to 382c) is connected to the second header collecting pipe (50) and communicates with the corresponding lower partial space (362a to 362c).

  The gas side header (385) includes one main body pipe part (386) and three connection pipe parts (387a to 387c). The main body pipe portion (386) is formed in a relatively large-diameter tubular shape whose upper end portion is bent in an inverted U shape. A pipe connecting the outdoor heat exchanger (30) and the third port of the four-way switching valve (17) is connected to the upper end of the main body pipe (386). The lower end of the main body pipe part (386) is closed. The connecting pipe portions (387a to 387c) protrude laterally from the linear portion of the main body pipe portion (386).

  With the above configuration, in the outdoor heat exchanger (30) of the present embodiment, the refrigerant flows in the direction of the arrow shown in FIG. 14 during the heating operation. Further, during the cooling operation, the refrigerant flows in the direction opposite to the arrow shown in FIG.

Also in the third embodiment, the first header collecting pipe (40) similar to that in the first embodiment and the modification described above is used. Thereby, a liquid refrigerant can be equally sent to each flat tube (31).
<< Embodiment 4 of the Invention >>
The outdoor heat exchanger of Embodiment 4 of invention is demonstrated. FIG. 16 is a front view illustrating a schematic configuration of the outdoor heat exchanger (30) of the fourth embodiment. FIG. 17 is a partial cross-sectional view showing the front of the outdoor heat exchanger (30) of the fourth embodiment.

  As shown in FIGS. 16 and 17, the outdoor heat exchanger (30) includes one second header collecting pipe (50), one first header collecting pipe (40), and a large number of flat tubes (31). And a large number of fins (235).

  As shown in FIG. 16, the flat tube (31) of the outdoor heat exchanger (30) is vertically divided into two heat exchange regions (451, 452). That is, the outdoor heat exchanger (30) has an upper heat exchange region (451) and a lower heat exchange region (452). Each heat exchanging region (451, 452) is divided into three heat exchanging portions (451a to 451c, 452a to 452c). Specifically, in the upper heat exchange region (451), the first main heat exchange part (451a), the second main heat exchange part (451b), and the third main heat exchange part in order from bottom to top. (451c) is formed. In the lower heat exchange region (452), the first auxiliary heat exchange unit (452a), the second auxiliary heat exchange unit (452b), and the third auxiliary heat exchange unit (452c) are arranged in order from bottom to top. And are formed. Thus, in the outdoor heat exchanger (30) of the present embodiment, a plurality of and the same number of heat exchange units (451a to 451c, 452a to 452c) in the upper heat exchange region (451) and the lower heat exchange region (452). ). As shown in FIG. 17, each main heat exchange section (451a to 451c) has eleven flat tubes (31), and each auxiliary heat exchange section (452a to 452c) has three flat tubes ( 31). In addition, the number of the heat exchange parts (451a to 451c, 452a to 452c) formed in each heat exchange region (451, 452) may be two, or may be four or more. Further, the number of flat tubes (31) communicating with each main heat exchange section (451a to 451c) and each auxiliary heat exchange section (452a to 452c) is not limited to this.

  The internal space of the second header collecting pipe (50) and the first header collecting pipe (40) is partitioned vertically by a plurality of partition plates (439).

  Specifically, the internal space of the second header collecting pipe (50) includes an upper space (461) corresponding to the upper heat exchange region (451) and a lower space (462) corresponding to the lower heat exchange region (452). ). The upper space (461) is a single space corresponding to all the main heat exchange units (451a to 451c). That is, the upper space (461) communicates with the flat tubes (31) of all the main heat exchange units (451a to 451c). The lower space (462) is further divided by the partition plate (439) into the same number (three) of communication spaces (462a) as the auxiliary heat exchange portions (452a to 452c) corresponding to the auxiliary heat exchange portions (452a to 452c). To 462c). In other words, in the lower space (462), the first communication space (462a) communicating with the flat tube (31) of the first auxiliary heat exchange section (452a) and the flat tube of the second auxiliary heat exchange section (452b) ( A second communication space (462b) communicating with 31) and a third communication space (462c) communicating with the flat tube (31) of the third auxiliary heat exchange section (452c) are formed.

  The internal space of the first header collecting pipe (40) is vertically partitioned into five communication spaces (471a to 471e). Specifically, the inner space of the first header collecting pipe (40) is the uppermost in the first main heat exchanging part (451a) and the lower heat exchanging area (452) positioned at the lowermost position in the upper heat exchanging area (451). The four auxiliary spaces (471a, 471b, 471d, 471e) corresponding to the main heat exchangers (451b, 451c) and the auxiliary heat exchangers (452a, 452b) excluding the third auxiliary heat exchanger (452c) ) And a single communication space (471c) corresponding to the first main heat exchange part (451a) and the third auxiliary heat exchange part (452c) in common. That is, in the internal space of the first header collecting pipe (40), the first communication space (471a) communicating with the flat pipe (31) of the first auxiliary heat exchange section (452a) and the second auxiliary heat exchange section (452b). ) Communicated with the flat tube (31) of the second communication space (471b) communicating with the flat tube (31) and the flat tubes (31) of both the third auxiliary heat exchange section (452c) and the first main heat exchange section (451a). A third communication space (471c), a fourth communication space (471d) communicating with the flat tube (31) of the second main heat exchange section (451b), and a flat tube (31) of the third main heat exchange section (451c) A fifth communication space (471e) that communicates with the vehicle is formed.

  In the first header collecting pipe (40), the fourth communication space (471d) and the fifth communication space (471e), and the first communication space (471a) and the second communication space (471b) are in pairs. It has become. Specifically, the first communication space (471a) and the fourth communication space (471d) are paired, and the second communication space (471b) and the fifth communication space (471e) are paired. The first header collecting pipe (40) includes a first communication pipe (472) connecting the first communication space (471a) and the fourth communication space (471d), a second communication space (471b), and a first communication space. A second communication pipe (473) that connects the five communication spaces (471e) is provided. That is, in the outdoor heat exchanger (30) of the present embodiment, the first main heat exchange part (451a) and the third auxiliary heat exchange part (452c) are paired, and the second main heat exchange part (451b) and the first The auxiliary heat exchange part (452a) is paired, and the third main heat exchange part (451c) and the second auxiliary heat exchange part (452b) are paired. In addition, the number of pairs of heat exchange units (451a to 451c, 452a to 452c) formed in the outdoor heat exchanger (30) is the number of pairs of main heat exchange units (451a to 451c) and auxiliary heat exchange units ( The total height of 452a to 452c) is appropriately set according to the height of the outdoor heat exchanger (30) so as to be approximately 350 mm or less (preferably about 300 to 350 mm).

  Thus, in the internal space of the first header collecting pipe (40), the same number as the main heat exchanging portions (451a to 451c) corresponding to the main heat exchanging portions (451a to 451c) of the upper heat exchanging region (451). (Three) communication spaces (471c, 471d, 471e) are formed, and the auxiliary heat exchanging units (452a to 452c) corresponding to the auxiliary heat exchanging units (452a to 452c) of the lower heat exchanging region (452) are formed. 452c) and the same number (three) of communication spaces (471a, 471b, 471c) are formed. The communication space (471c, 471d, 471e) corresponding to the upper heat exchange region (451) and the communication space (471a, 471b, 471c) corresponding to the lower heat exchange region (452) communicate with each other.

  As shown in FIG. 16, the outdoor heat exchanger (30) is provided with a liquid side connection member (480) and a gas side connection member (485). The liquid side connection member (480) and the gas side connection member (485) are attached to the second header collecting pipe (50).

  The liquid side connection member (480) includes one shunt (481) and three small diameter tubes (482a to 482c). A pipe connecting the outdoor heat exchanger (30) and the expansion valve (18) is connected to the lower end of the flow divider (481). One end of each small diameter pipe (482a to 482c) is connected to the upper end of the flow divider (481). Inside the shunt (481), the pipe connected to the lower end thereof communicates with the small diameter pipes (482a to 482c). The other end of each small diameter pipe (482a to 482c) is connected to the lower space (462) of the second header collecting pipe (50) and communicates with the corresponding communication space (462a to 462c). However, the portion opened to the corresponding communication space (462a to 462c) in each small diameter tube (482a to 482c) is not limited to the lower end.

  As shown also in FIG. 17, each small diameter pipe (482a-482c) is opened in the part near the lower end of corresponding communication space (462a-462c). That is, the first small diameter pipe (482a) opens in a portion near the lower end of the first communication space (462a), and the second small diameter pipe (482b) opens in a portion near the lower end of the second communication space (462b). The third small-diameter pipe (482c) opens at a portion near the lower end of the third communication space (462c). In addition, the length of each small diameter pipe | tube (482a-482c) is set individually so that the difference in the flow volume of the refrigerant | coolant which flows into each auxiliary heat exchange part (452a-452c) may become as small as possible.

  The gas side connection member (485) is comprised by one piping with a comparatively large diameter. One end of the gas side connection member (485) is connected to a pipe connecting the outdoor heat exchanger (30) and the third port of the four-way switching valve (17). The other end of the gas side connection member (485) opens to a portion near the upper end of the upper space (461) in the second header collecting pipe (50).

  With the above configuration, in the outdoor heat exchanger (30) of the present embodiment, the refrigerant flows in the direction of the arrow shown in FIG. 16 during the heating operation. Further, during the cooling operation, the refrigerant flows in the direction opposite to the arrow shown in FIG.

Also in the fourth embodiment, the first header collecting pipe (40) similar to that in the first embodiment and the modification described above is used. Thereby, a liquid refrigerant can be equally sent to each flat tube (31).
<< Embodiment 5 of the Invention >>
The outdoor heat exchanger of Embodiment 5 of invention is demonstrated. FIG. 18 is a front view illustrating a schematic configuration of the outdoor heat exchanger (30) of the fifth embodiment. FIG. 19 is a partial cross-sectional view showing the front of the outdoor heat exchanger (30) of the fifth embodiment.

  As shown in FIG. 18, the flat tube (31) of the outdoor heat exchanger (30) is divided into an upper heat exchange region (451) and a lower heat exchange region (452) in the vertical direction as in the fourth embodiment. Has been. The upper heat exchange region (451) is divided into three main heat exchange units (451a to 451c) arranged vertically, and the lower heat exchange region (452) is composed of one auxiliary heat exchange unit (452a). Yes. That is, in the upper heat exchange region (451), the first main heat exchange unit (451a), the second main heat exchange unit (451b), and the third main heat exchange unit (451c) are sequentially arranged from bottom to top. ) And are formed. As shown in the figure, each main heat exchanger (451a to 451c) has eleven flat tubes (31), and the auxiliary heat exchanger (452a) has nine flat tubes (31). doing. Note that the number of main heat exchange units (451a to 451c) formed in the upper heat exchange region (451) may be two, or four or more. Moreover, the number of the flat tubes (31) which each main heat exchange part (451a-451c) and auxiliary heat exchange part (452a) have is not restricted to this.

  The internal space of the second header collecting pipe (50) and the first header collecting pipe (40) is partitioned up and down by a partition plate (439).

  Specifically, the internal space of the second header collecting pipe (50) includes an upper space (461) corresponding to the upper heat exchange region (451) and a lower space (462) corresponding to the lower heat exchange region (452). ) (Communication space (462a)). The upper space (461) is a single space corresponding to all the main heat exchange units (451a to 451c). That is, the upper space (461) communicates with the flat tubes (31) of all the main heat exchange units (451a to 451c). The lower space (462) (communication space (462a)) is a single space corresponding to one auxiliary heat exchange part (452a), and communicates with the flat tube (31) of the auxiliary heat exchange part (452a). ing.

  The internal space of the first header collecting pipe (40) is partitioned into four communication spaces (471a to 471d) in the vertical direction. Specifically, the internal space of the first header collecting pipe (40) includes three communication spaces (471b, 471c, 471d) corresponding to the main heat exchange portions (451a to 451c) of the upper heat exchange region (451). And a single communication space (471a) corresponding to the auxiliary heat exchange section (452a) of the lower heat exchange region (452). That is, in the internal space of the first header collecting pipe (40), the first communication space (471a) communicating with the flat pipe (31) of the auxiliary heat exchange section (452a) and the first main heat exchange section (451a). A second communication space (471b) communicating with the flat tube (31), a third communication space (471c) communicating with the flat tube (31) of the second main heat exchange section (451b), and a third main heat exchange section A fourth communication space (471d) communicating with the flat tube (31) of (451c) is formed.

  A communication member (475) is provided in the first header collecting pipe (40). The communication member (475) includes one shunt (476), one main pipe (477), and three small diameter pipes (478a to 478c). One end of the main pipe (477) is connected to the lower end of the flow divider (476), and the other end is connected to the first communication space (471a) of the first header collecting pipe (40). One end of each small diameter pipe (478a to 478c) is connected to the upper end of the flow divider (476). In the flow divider (476), the main pipe (477) and the small diameter pipes (478a to 478c) communicate with each other. The other ends of the small diameter tubes (478a to 478c) communicate with the corresponding second to fourth communication spaces (471b to 471d) of the first header collecting tube (40).

  As shown in FIG. 19, each small-diameter pipe (478a to 478c) opens at a portion near the lower end of the corresponding second to fourth communication space (471b to 471d). That is, the first small diameter pipe (478a) opens at a portion near the lower end of the second communication space (471b), and the second small diameter pipe (478b) opens at a portion near the lower end of the third communication space (471c). The third small-diameter pipe (478c) opens at a portion near the lower end of the fourth communication space (471d). In addition, the length of each small diameter pipe | tube (478a-478c) is set individually so that the difference of the flow volume of the refrigerant | coolant which flows into each main heat exchange part (451a-451c) may become as small as possible. In this way, the communication member (475) of the first header collecting pipe (40) extends from the first communication space (471a) to the second to fourth communication spaces (451a to 451c) corresponding to the main heat exchange units (451a to 451c). 471b to 471d). That is, in the first header collecting pipe (40), the communication space (471a) corresponding to the lower heat exchange region (452) and the communication spaces (471b, 471c, 471d) corresponding to the upper heat exchange region (451) Are communicating.

   As shown in FIG. 18, the outdoor heat exchanger (30) is provided with a liquid side connecting member (486) and a gas side connecting member (485). The liquid side connection member (486) and the gas side connection member (485) are attached to the second header collecting pipe (50). The liquid side connection member (486) is composed of a single pipe having a relatively large diameter. One end of the liquid side connecting member (486) is connected to a pipe connecting the outdoor heat exchanger (30) and the expansion valve (18). The other end of the liquid side connection member (486) opens to the lower space (462) (communication space (462a)) near the lower end of the second header collecting pipe (50). It is not a thing. The gas side connecting member (485) is composed of a single pipe having a relatively large diameter. One end of the gas side connection member (485) is connected to a pipe connecting the outdoor heat exchanger (30) and the third port of the four-way switching valve (17). The other end of the gas side connection member (485) opens in a portion near the upper end of the upper space (461) in the second header collecting pipe (50).

  With the above configuration, in the outdoor heat exchanger (30) of the present embodiment, the refrigerant flows in the direction of the arrow shown in FIG. 18 during the heating operation. Further, during the cooling operation, the refrigerant flows in the direction opposite to the arrow shown in FIG.

  Also in the fifth embodiment, the first header collecting pipe (40) similar to that in the first embodiment and the modification described above is used. Thereby, a liquid refrigerant can be equally sent to each flat tube (31).

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

<Modified fins>
The fins of the heat exchanger (30) according to the embodiment are corrugated fins (35) that are corrugated fins that are disposed between flat tubes (31) that are vertically adjacent to each other. In addition, a plurality of louvers (37) for promoting heat transfer are formed in the heat transfer section (36) of the corrugated fin (35). However, the fin (70) of a modification as shown in FIG.20 and FIG.21 may be employ | adopted for a heat exchanger (30).

  The fin (70) of a modification is a vertically long fin which integrally connected the some heat-transfer part (36) arrange | positioned between each flat tube (31) and arranged up and down. Specifically, a connecting plate portion (71) is formed on the fin (70) on the leeward side (right side in FIG. 20) of the flat tube (31). The connecting plate portion (71) extends vertically so as to be connected to the leeward side end portions of the plurality of heat transfer portions (36) arranged vertically. A notch (72) into which the flat tube (31) is inserted is formed between each heat transfer section (36) and the connecting plate section (71). The fin (70) and the flat tube (31) are joined to each other by brazing in a state where the flat tube (31) is inserted into the notch (72).

  In the heat transfer section (36) of the fin (70) of the modified example, a plurality of waffle sections (73) for promoting heat transfer are formed instead of the louver (37) of the above-described embodiment. Each waffle portion (73) bulges toward the ventilation path and constitutes a bulge portion that is vertically formed vertically. In the fin (70) of this example, four waffle portions (73) are arranged in the ventilation direction of the ventilation path.

  The waffle part (73) is formed by plastically deforming a part of the heat transfer part (36) by press working or the like. Each waffle portion (73) has a pair of vertically long trapezoidal surfaces (73a, 73a) and a pair of flat triangular surfaces (73b, 73b). The pair of trapezoidal surfaces (73a, 73a) are adjacent to each other in the ventilation direction so as to form a mountain fold (73c) that forms a ridgeline between them. The pair of triangular surfaces (73b, 73b) are formed up and down across the mountain fold (73c).

  In the heat transfer part (36), the height of the flat part (75) formed between the lower end of the waffle part (73) and the flat tube (31) below the waffle part (73) It gets smaller as you go to the side. With this configuration, water (drain water) melted on the surface of the fin (70) can be quickly discharged to the leeward side through the flat portion (75) during the defrosting operation described above. That is, when frost adheres to the surface of the fin (70), the amount of frost in the windward side portion increases. On the other hand, if the height of the windward flat portion (75) is increased as described above, a sufficient gap can be secured between the adjacent heat transfer portions (36) in this region. Therefore, drain water melted on the windward side can be quickly discharged. Further, by reducing the height of the leeward flat portion (75), drain water generated on the leeward side can be quickly discharged by capillary action.

  Each waffle portion (73) is inclined obliquely with respect to the vertical direction such that the lower end is closer to the leeward side than the upper end. Thereby, in the defrosting operation mentioned above, the drain water produced on the surface of each waffle part (73) can be quickly discharged to the leeward side.

  A front tab (76) and a rear tab (77) are formed on the fin (70) of the modified example. The front tab (76) is formed at the windward end of each heat transfer section (36). The rear tab (77) is formed on the leeward side of each notch (72) in the connecting plate (71). The front tab (76) and the rear tab (77) are formed by cutting and raising a part of the fin (70) to the air passage side. Specifically, the front tab (76) and the rear tab (77) are formed as cut-and-raised surfaces (76a, 76b) formed inside the cut after forming a substantially U-shaped cut in the fin (70). It is formed by bending to the ventilation path side. The height of the cut-and-raised portions of the front tab (76) and the rear tab (77) is set to a height that allows contact with the adjacent fin (70). That is, the front tab (76) and the rear tab (77) function as spacers for securing a predetermined interval between the adjacent fins (70).

  The cut-and-raised surface (76a) of the front tab (76) is bent obliquely upward on the leeward side. The cut-and-raised surface (77a) of the rear tab (77) is bent to the windward side. That is, each cut-and-raised surface (76a, 77a) is inclined with respect to the horizontal plane. As a result, even when drain water is generated above each tab (76, 77) during the above-described defrosting operation, the drain water is quickly caused to flow downward along the surface of the tab (76, 77). be able to.

  On the connecting plate portion (71) of the fin (70) of the modified example, a water guide rib (78) extending in the vertical direction is formed. The water guiding rib (78) is formed from the upper end to the lower end of the connecting plate portion (71). The water guide rib (78) has a protrusion (78a) formed on one side surface of the connecting plate portion (71) and a groove (78b) formed on the other side surface. In each adjacent connecting plate portion (71), the projection (78a) of the water guide rib (78) is formed on the side surface on the same side. The water guiding rib (78) drains water (drain water) melted on the surface of the fin (70) during the above-described defrosting operation. That is, the drain water generated during the defrosting operation flows down due to gravity while being guided by the protrusion (78a) and the groove (78b) of the water guide rib (78).

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a heat exchanger in which a plurality of flat tubes are connected in parallel to a header collecting tube, and an air conditioner including the heat exchanger.

10 Air conditioner
30 heat exchanger
31 flat tube
32 Refrigerant passage
40 1st header collecting pipe (header collecting pipe)
41 Perimeter wall
42 Insertion surface
43 Opposite surface
43a Small diameter circular arc part
43b Large-diameter arc part
44 Opposite surface
45 Opposite surface
45a Arc part
45b Plane section

Claims (5)

A tubular header collecting pipe (40) in which a refrigerant containing liquid is guided upward;
Each other physician are arranged vertically so as to face the a heat exchanger having a plurality of flat tubes (31) and to be inserted into the header manifold (40),
The entire inner peripheral surface of the peripheral wall portion (41) of the header collecting pipe (40) is curved toward the flat tube (31) side and the insertion surface (42) through which the flat tube (31) is inserted, and the insertion And an opposing surface (43,4 4) facing the surface (42),
In a cross section perpendicular to the axis of the header collecting pipe (40), if a line segment X connecting two connection points between the insertion surface (42) and the opposing surface (43,4 4) is used as a reference, the line segment The maximum length from X to the facing surface (43,4 4) is shorter than the maximum length from the line segment X to the insertion surface (42) ,
The open end (31a) of the flat tube (31) is formed in a flat shape,
The facing surface (43, 44) bulges on the opposite side of the flat tube (31) so that the maximum length from the line segment X to the facing surface (43, 44) is greater than zero. heat exchanger according to claim <br/> Being. In claim 1,
The heat exchanger according to claim 1, wherein the facing surface (44) is formed in an elliptical arc shape having the line segment X as a major axis. In claim 1,
The opposing surface (43) has two regular arc-shaped small-diameter arc portions (43a) each continuous with the insertion surface (42), and an arc radius longer than the arc radius of the small-diameter arc portion (43a). And a large circular arc portion (43b) having a regular arc shape formed between the two small circular arc portions (43a). In any one of Claims 1 thru | or 3 ,
The said insertion surface (42) is formed in the shape of a regular arc, The heat exchanger characterized by the above-mentioned. A refrigerant circuit (15) provided with the heat exchanger (30) according to any one of claims 1 to 4 ,
An air conditioner that performs a refrigeration cycle by circulating a refrigerant in the refrigerant circuit (15).

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