WO2012098912A1

WO2012098912A1 - Heat exchanger and air conditioner

Info

Publication number: WO2012098912A1
Application number: PCT/JP2012/000367
Authority: WO
Inventors: 正憲神藤; 好男織谷; 宏和藤野; 俊光鎌田; 菊池　芳正
Original assignee: ダイキン工業株式会社
Priority date: 2011-01-21
Filing date: 2012-01-23
Publication date: 2012-07-26
Also published as: US20130292098A1; JP5617935B2; KR20130129265A; AU2012208118A1; EP2667134A1; KR101451057B1; EP2667134A4; CN103339457A; JPWO2012098912A1

Abstract

A plurality of flat tubes (53, 58), first header/collector tubes (51, 56), and second header/collector tubes (52, 57) are provided to reduce pressure loss in an auxiliary heat exchange unit. Each flat tube (53, 58) has one end thereof connected to a first header/collector tube (51, 56), and the other end thereof connected to a second header/collector tube (52, 57). Of the plurality of flat tubes (53, 58), the flat tubes (53) configure a principal heat exchange unit (50), while the remaining flat tubes (58) configure an auxiliary heat exchange unit (55). The flat tubes (58) in the auxiliary heat exchange unit (55) comprise a smaller number of tubes than the flat tubes (53) in the principal heat exchange unit (50). The total cross-sectional area of a channel (49) per one flat tube (58) provided in the auxiliary heat exchange unit (55) is greater than the total cross-sectional area of the channel (49) per one flat tube (53) provided in the principal heat exchange unit (50).

Description

Heat exchanger and air conditioner

The present invention relates to a heat exchanger and an air conditioner that include a flat tube and fins and exchange heat with air flowing in the flat tube.

Conventionally, a refrigeration apparatus capable of performing a refrigeration cycle by circulating a refrigerant in a refrigerant circuit and cooling an object (for example, air or water) with the refrigerant and an operation for heating the object with the refrigerant. Are known. For example, Patent Document 1 discloses an air conditioner configured by this type of refrigeration apparatus. In an air conditioner during cooling operation that cools indoor air, the outdoor heat exchanger functions as a condenser, and the indoor heat exchanger functions as an evaporator. On the other hand, in an air conditioner during heating operation that heats indoor air, the indoor heat exchanger functions as a condenser and the outdoor heat exchanger functions as an evaporator.

Patent Document 2 also discloses an air conditioner that performs a refrigeration cycle. The refrigerant circuit of this air conditioner is provided with an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air. This outdoor heat exchanger is constituted by a heat exchanger having two headers each formed in a cylindrical shape and a number of flat heat transfer tubes provided between the two headers.

A heat exchanger having a header and a flat heat transfer tube is also disclosed in Patent Document 3. The heat exchanger of patent document 3 functions as a condenser. In this heat exchanger, a main heat exchanging section for condensation and an auxiliary heat exchanging section for supercooling are formed. The refrigerant that has flowed into the heat exchanger is condensed while passing through the main heat exchanging section to be substantially in a liquid single-phase state, and thereafter flows into the auxiliary heat exchanging section to be further cooled.

JP 2008-064447 A Japanese Patent Laid-Open No. 09-014698 JP 2010-025447 A

However, in a heat exchanger having a header and a flat heat transfer tube (flat tube), when the main heat exchange part for condensation and the auxiliary heat exchange part for supercooling are formed, the auxiliary heat exchange part is the main heat exchange part. Generally, the number of flow paths is smaller than that of the heat exchange section, and the flow velocity increases in the auxiliary heat exchange section, and the pressure loss may increase in the auxiliary heat exchange section.

The present invention has been made paying attention to the above problems, and in a heat exchanger having a header and a flat tube and having a main heat exchange part for condensation and an auxiliary heat exchange part for supercooling, It aims at enabling it to reduce the pressure loss in an auxiliary heat exchange part.

In order to solve the above problem, the first invention is:
Between a plurality of flat tubes (53,58) in which a plurality of fluid flow paths (49) are formed inside, and the adjacent flat tubes (53,58) arranged side by side so as to face each other A heat exchanger comprising a plurality of fins (54, 59) partitioned into a plurality of ventilation paths through which air flows,
A first header collecting pipe (51, 56);
A second header collecting pipe (52, 57),
Each of the flat tubes (53, 58) has one end connected to the first header collecting pipe (51, 56) and the other end connected to the second header collecting pipe (52, 57).
Some flat tubes (53) of the plurality of flat tubes (53,58) constitute the main heat exchange part (50), and the remaining flat tubes (58) constitute the auxiliary heat exchange part (55). And
The number of flat tubes (58) constituting the auxiliary heat exchange section (55) is less than the number of flat tubes (53) constituting the main heat exchange section (50),
The total cross-sectional area of the flow path (49) per flat pipe (58) in the auxiliary heat exchange section (55) is the flow path per flat pipe (53) in the main heat exchange section (50) ( 49) greater than the total cross-sectional area of
When the heat exchanger is a condenser, the refrigerant is condensed in the main heat exchange section (50), and the refrigerant is supercooled in the auxiliary heat exchange section (55).

In this configuration, the number of flat tubes (58) constituting the auxiliary heat exchange section (55) is smaller than the number of flat tubes (53) constituting the main heat exchange section (50). However, the total cross-sectional area of the flow path (49) per one flat tube (58) in the auxiliary heat exchange section (55) is the flow path per one flat pipe (53) in the main heat exchange section (50). It is configured to be larger than the total cross-sectional area of (49). Therefore, when the heat exchanger is a condenser, the flow rate of the refrigerant in the auxiliary heat exchanging part (55) as compared with a heat exchanger in which the main heat exchanging part and the auxiliary heat exchanging part are configured by one type of flat tube. It becomes possible to slow down.

In addition, the second invention,
In the heat exchanger of the first invention,
The width (W2) of the flat tube (58) of the auxiliary heat exchanger (55) is larger than the width (W1) of the flat tube (53) of the main heat exchanger (50),
The number of flow paths per flat tube (58) of the auxiliary heat exchange section (55) is larger than the number of flow paths per flat pipe (53) of the main heat exchange section (50). And

In this configuration, the total number of channels per flat tube (53,58) and the width (W1, W2) are adjusted, and the total cross section of the flow channel (49) per flat tube (53,58) Is set.

In addition, the third invention,
In the heat exchanger of the first or second invention,
A plurality of grooves are formed in the flow path (49) of the flat tube (53) of the main heat exchange part (50),
The flat tube (58) of the auxiliary heat exchange part (55) is a bare tube.

In this configuration, in the flat tube (53) for the main heat exchange section (50), it is possible to further increase the surface area per one refrigerant flow path (49) by providing the groove (49a). .

In addition, the fourth invention is
In any one of the heat exchangers of the first to third inventions,
The fins (236) are formed in a plate shape provided with a plurality of notches (245) for inserting the flat tubes (53, 58), and are predetermined to each other in the extending direction of the flat tubes (53, 58). The flat tube (53,58) is sandwiched at the periphery of the notch (245),
The fin (236) is characterized in that a portion between the vertically adjacent cutout portions (245) constitutes a heat transfer portion (237).

In this configuration, the plurality of fins (236) formed in a plate shape are arranged at predetermined intervals in the extending direction of the flat tube (53, 58). Each fin (236) is formed with a plurality of notches (245) for inserting the flat tubes (53, 58). As for each fin (236), the peripheral part of the notch (245) has pinched the flat tube (53,58). And in each fin (236), the part between the notch parts (245) adjacent up and down comprises a heat-transfer part (237).

In addition, the fifth invention,
In the heat exchanger of the fourth invention,
The ends in the width direction of the flat tubes (53, 58) are aligned with the ends on the entrance side of the notches (245).

In this configuration, the end in the width direction of the flat tube (53, 58) is aligned with the end on the notch (245) side. Therefore, when the brazing material for joining the fin (236) and the heat transfer tube (53, 58) is arranged on the side of the notch (245), it can be easily set.

In addition, the sixth invention,
A refrigerant circuit (20) provided with the heat exchanger (40) according to any one of the first to fifth inventions;
In the refrigerant circuit (20), the refrigerant is circulated to perform a refrigeration cycle.

In this configuration, the heat exchanger is connected to the refrigerant circuit (20). In the heat exchanger, the refrigerant circulating in the refrigerant circuit (20) flows through the flow path (49) of the flat tube (53, 58) and exchanges heat with the air flowing through the ventilation path.

According to the first invention, when the heat exchanger is a condenser, the flow rate of the refrigerant in the auxiliary heat exchanging section (55) can be reduced, and therefore in the auxiliary heat exchanging section (55). Pressure loss can be reduced.

Moreover, according to 2nd invention, the total cross-sectional area of the flow path (49) in the flat tube (53) for main heat exchange parts (50), and the flat tube (58) for auxiliary heat exchange parts (55) The total cross-sectional area of the flow path (49) can be easily set. Further, for example, the shape of the flow path (49) is different between the main heat exchange section (50) and the auxiliary heat exchange section (55), and the difference in the flow path (49) shape can be identified visually. Even in difficult cases, the flat tubes (53) for the main heat exchanger (50) and the flat tubes (58) for the auxiliary heat exchanger (55) have different widths (W1, W2). Therefore, both can be easily identified visually.

Further, according to the third invention, in the flat tube (53) for the main heat exchange section (50), it becomes possible to improve the heat exchange efficiency in the main heat exchange section (50). Further, in the flat tube (58) for the auxiliary heat exchange section (55), the pressure loss due to the shape can be further reduced.

Further, according to the fifth invention, the brazing material for joining the fin (236) and the heat transfer tube (53, 58) can be easily set, so that both can be joined more reliably. Also, since the end of the flat tube (53,58) is aligned with the end of the notch (245) at the entrance side, when using flat tubes (53,58) with different widths, The depth of the notch (245) may be set according to 58). That is, even if a plurality of types of flat tubes (53, 58) having different widths are used, the fin (236) can be shared.

FIG. 1 is a refrigerant circuit diagram of the air conditioner of Embodiment 1, and shows a state during cooling operation. FIG. 2 is a refrigerant circuit diagram of the air conditioner of Embodiment 1, and shows a state during heating operation. FIG. 3 is a schematic perspective view of a heat exchanger unit constituting the outdoor heat exchanger of the first embodiment. FIG. 4 is a schematic front view showing a heat exchanger unit constituting the outdoor heat exchanger of the first embodiment. FIG. 5 is an enlarged perspective view showing a main part of the heat exchange unit of Embodiment 1 with a part thereof omitted. FIG. 6 is a diagram schematically illustrating an example of a cross-sectional shape of a flat tube. 7A is a diagram for explaining an example of a cross-sectional shape of a refrigerant flow path in a flat tube for a main heat exchange section, and FIG. 7B is a refrigerant in a refrigerant flow path in a flat tube for an auxiliary heat exchange section. It is a figure explaining an example of the section shape of a channel. FIG. 8 is a diagram illustrating a part of a cross section of the heat exchanger according to the first modification of the first embodiment. FIG. 9 is a schematic perspective view of fins provided in the heat exchanger of the first modification. FIG. 10 is a view showing the heat transfer section provided on the fin of the heat exchanger of the first modification, wherein (A) is a front view of the heat transfer section, and (B) is a B- It is sectional drawing which shows B cross section. FIG. 11A is a cross-sectional view of a part of the heat exchanger of the second modification, and FIG. 11B is a cross-sectional view of the fin showing the VV cross section of FIG. 11A. FIG. 12 is a diagram illustrating a part of a cross section of the heat exchanger according to the third modification of the first embodiment. FIGS. 13A and 13B are views showing the main parts of the fins of the heat exchanger of the third modification, wherein FIG. 13A is a front view of the fins, and FIG. 13B is a cross-sectional view showing a GG cross section of FIG. It is. FIG. 14A is a cross-sectional view of a part of the heat exchanger according to the fourth modification, and FIG. 14B is a cross-sectional view of the fin showing the XX cross section of FIG. 14A. FIG. 15 is a front view illustrating a schematic configuration of the outdoor heat exchanger according to the second embodiment. FIG. 16 is a partial cross-sectional view illustrating the front of the outdoor heat exchanger according to the second embodiment. FIG. 17 is a front view illustrating a schematic configuration of the outdoor heat exchanger according to the third embodiment. FIG. 18 is a partial cross-sectional view illustrating the front of the outdoor heat exchanger according to the third embodiment. FIG. 19 is a front view illustrating a schematic configuration of the outdoor heat exchanger according to the fourth embodiment. FIG. 20 is a partial cross-sectional view illustrating the front of the outdoor heat exchanger according to the fourth embodiment. FIG. 21 is a front view illustrating a schematic configuration of the outdoor heat exchanger according to the fifth embodiment. FIG. 22 is a partial cross-sectional view showing the front of the outdoor heat exchanger of the fifth embodiment. FIG. 23 is a front view illustrating a schematic configuration of the outdoor heat exchanger according to the sixth embodiment. FIG. 24 is a partial cross-sectional view illustrating the front of the outdoor heat exchanger according to the sixth embodiment. FIG. 25 is a diagram illustrating a part of a cross section of the outdoor heat exchanger according to the seventh embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

Embodiment 1 of the Invention
A first embodiment of the present invention will be described. The present embodiment is an air conditioner configured by a refrigeration apparatus.

<Overall configuration of air conditioner>
FIG. 1 is a refrigerant circuit diagram of an air conditioner (10) according to Embodiment 1 of the present invention, and shows a state during cooling operation. FIG. 2 is a refrigerant circuit diagram of the air conditioner (10) of the first embodiment, and shows a state during heating operation. As shown in FIG. 1, the air conditioner (10) of the present embodiment includes an indoor unit (12) that is a use side unit and an outdoor unit (11) that is a heat source side unit. In the air conditioner (10), the refrigerant circuit (20) is formed by connecting the outdoor unit (11) and the indoor unit (12) with a pipe.

The number of indoor units (12) and outdoor units (11) is just an example. That is, in the air conditioner (10) of the present embodiment, the refrigerant circuit (20) may be formed by connecting a plurality of indoor units (12) to a single outdoor unit (11), The refrigerant circuit (20) may be formed by connecting a plurality of outdoor units (11) and a plurality of indoor units (12) to each other.

The refrigerant circuit (20) includes a compressor (31), an outdoor heat exchanger (40) that is a heat source side heat exchanger, an indoor heat exchanger (32) that is a use side heat exchanger, an expansion valve ( 33) and a four-way selector valve (34). The compressor (31), the outdoor heat exchanger (40), the expansion valve (33), and the four-way switching valve (34) are accommodated in the outdoor unit (11). The indoor heat exchanger (32) is accommodated in the indoor unit (12). Although not shown, the outdoor unit (11) is provided with an outdoor fan for supplying outdoor air to the outdoor heat exchanger (40), and the indoor unit (12) is connected to the indoor heat exchanger (32) indoors. An indoor fan for supplying air is provided.

Compressor (31) is a hermetic rotary compressor or scroll compressor. In the refrigerant circuit (20), the compressor (31) has a discharge pipe connected to the first port of the four-way switching valve (34) via a pipe, and a suction pipe connected to the second port of the four-way switching valve (34). Connected through a pipe.

The outdoor heat exchanger (40) includes a first header member (46) and a second header member (47) which are erected, and a large number of heat transfer tubes (53, 58) (hereinafter also referred to as flat tubes). Then, the refrigerant exchanges heat with outdoor air. The detailed structure of the outdoor heat exchanger (40) will be described later. The indoor heat exchanger (32) is a so-called cross fin type fin-and-tube heat exchanger, and exchanges heat between the refrigerant and room air.

The expansion valve (33) is a so-called electronic expansion valve (33). The four-way switching valve (34) has four ports, the first state where the first port communicates with the third port and the second port communicates with the fourth port (the state shown in FIG. 1), The first port is switched to the second state (the state shown in FIG. 2) in which the first port communicates with the fourth port and the second port communicates with the third port.

The refrigerant circuit (20) is provided with a first gas side pipe (21), a second gas side pipe (22), and a liquid side pipe (23). The first gas side pipe (21) has one end connected to the third port of the four-way switching valve (34) and the other end connected to the upper end of the first header member (46) of the outdoor heat exchanger (40). Has been. The second gas side pipe (22) has one end connected to the fourth port of the four-way switching valve (34) and the other end connected to the gas side end of the indoor heat exchanger (32). One end of the liquid side pipe (23) is connected to the lower end of a first header collecting pipe (56) described later, and the other end is connected to the liquid side end of the indoor heat exchanger (32). An expansion valve (33) is provided in the middle of the liquid side pipe (23).

<Structure of outdoor heat exchanger>
The detailed structure of the outdoor heat exchanger (40) will be described with reference to FIGS. FIG. 3 is a schematic perspective view of a heat exchanger unit constituting the outdoor heat exchanger of the first embodiment. FIG. 4 is a schematic front view showing a heat exchanger unit constituting the outdoor heat exchanger of the first embodiment. FIG. 5 is an enlarged perspective view showing a main part of the heat exchange unit of Embodiment 1 with a part thereof omitted.

The outdoor heat exchanger (40) of the present embodiment is constituted by one heat exchanger unit (45).

As shown in FIGS. 3 and 4, the heat exchanger unit (45) constituting the outdoor heat exchanger (40) includes one first header member (46), one second header member (47), and A large number of heat transfer tubes (53,58) and a large number of fins (54,59) are provided. The first header member (46), the second header member (47), the flat tubes (53, 58), and the fins (54, 59) are all made of an aluminum alloy and are joined to each other by brazing. ing. These fins (54, 59) partition between adjacent flat tubes (53, 58) into a plurality of ventilation paths through which air flows.

The first header member (46) and the second header member (47) are both formed in an elongated hollow cylindrical shape with both ends closed. In FIG. 4, the first header member (46) is erected at the left end of the heat exchanger unit (45), and the second header member (47) is erected at the right end of the heat exchanger unit (45). That is, the first header member (46) and the second header member (47) are installed in a posture in which the respective axial directions are in the vertical direction.

As shown in FIG. 5, the heat transfer tubes (53, 58) have a flat shape, and a plurality of refrigerant flow paths (49) are formed in a row therein. Below, a heat exchanger tube (53,58) is also called a flat tube. FIG. 6 is a diagram schematically showing an example of a cross-sectional shape of the flat tube (53, 58). In this example, as shown in FIG. 6, the width (W2) of the flat tube (58) is larger than the width (W1) of the flat tube (53). Further, the number of channels per flat tube (58) is larger than the number of channels per flat tube (53).

FIG. 7 is a diagram for explaining an example of the cross-sectional shape of the refrigerant flow path (49) in the flat tube (53) for the main heat exchange section (50) described later, and (B) is described later. It is a figure explaining an example of the section shape of the refrigerant channel (49) of the refrigerant channel (49) in the flat tube (58) for the auxiliary heat exchanging part (55). In the example shown in FIG. 7, the flat tube (53) has a plurality of grooves (49a) formed in the respective refrigerant flow paths (49). On the other hand, the flat tube (58) is a so-called bare tube (inner surface smooth tube) and has a circular cross section. That is, the groove (49a) is not formed in each refrigerant channel (49) of the flat tube (58). In this example, the refrigerant channel (49) of the flat tube (58) has a diameter of approximately 0.5 mm. Of course, the cross-sectional shapes of these refrigerant flow paths (49) are merely examples, and other shapes (for example, a square cross-section shown in FIG. 6 and the like) can be adopted.

In the heat exchanger unit (45), the flat tubes (53, 58) have the first header member (46) and the second header member (47) in a posture in which the respective axial directions are in the left-right direction and the side surfaces face each other. Are arranged at predetermined intervals in the axial direction. That is, in the heat exchanger unit (45), the flat tubes (53, 58) are arranged in parallel to each other from the first header member (46) to the second header member (47). Each flat tube (53, 58) has one end inserted into the first header member (46) and the other end inserted into the second header member (47). One end of the refrigerant flow path (49) in each flat tube (53, 58) communicates with the internal space of the first header member (46), and the other end communicates with the internal space of the second header member (47). is doing.

The fins (54, 59) are provided between the adjacent flat tubes (53, 58). Each fin (54, 59) is formed in the shape of a corrugated plate that snakes up and down, and is installed in such a posture that the ridge line of the corrugation is the front-rear direction of the heat exchanger unit (45) (the direction perpendicular to the paper surface of FIG. 4). Has been. In the heat exchanger unit (45), air passes in a direction perpendicular to the paper surface of FIG.

As shown in FIG. 4, the first header member (46) is provided with a disc-shaped partition plate (48). The internal space of the first header member (46) is partitioned up and down by a partition plate (48). On the other hand, the internal space of the second header member (47) is a single undivided space.

In the heat exchanger unit (45), the upper part of the partition plate (48) constitutes the main heat exchange part (50), and the lower part of the partition plate (48) is the auxiliary heat exchange part (55). Is configured.

Specifically, in the first header member (46), the upper part of the partition plate (48) constitutes the first header collecting pipe (51) of the main heat exchange section (50), and the partition plate (48) The lower part constitutes the first header collecting pipe (56) of the auxiliary heat exchange part (55). The flat tubes (53,58) provided in the heat exchanger unit (45) are connected to the first header collecting pipe (51) of the main heat exchange section (50), and the flat tubes of the main heat exchange section (50). The pipe (53) that is connected to the first header collecting pipe (56) of the auxiliary heat exchange section (55) is the flat pipe (58) of the auxiliary heat exchange section (55). The fins (54, 59) provided in the heat exchanger unit (45) are provided between the flat tubes (53) of the main heat exchange part (50), and the main heat exchange part (50) The fin (54) of the auxiliary heat exchanger (55) is provided between the flat tubes (58) of the auxiliary heat exchanger (55). In the second header member (47), the portion where the flat tube (53) of the main heat exchange part (50) is inserted constitutes the second header collecting pipe (52) of the main heat exchange part (50), and the auxiliary heat The part where the flat pipe (58) of the exchange part (55) is inserted constitutes the second header collecting pipe (57) of the auxiliary heat exchange part (55).

In the outdoor heat exchanger (40), the width (W1) of the flat tube (53), the number of refrigerant channels (49), the number of refrigerant channels, Determine the cross-sectional area of (49), the number of flat tubes (53), etc. Generally, the number of flat tubes (53, 58) that can be provided in the outdoor heat exchanger (40) is limited. Therefore, for example, the number of flat tubes (58) is set to the number obtained by subtracting the number of flat tubes (53) from the maximum number that can be provided. Based on the determined number, the width (W2) of the flat tube (58), the number of refrigerant flow paths (49), and the cross-sectional area of the refrigerant flow path (49) are required for the auxiliary heat exchange section (55). Set according to ability.

Specifically, in the outdoor heat exchanger (40) of the present embodiment, the number of flat tubes (58) of the auxiliary heat exchange unit (55) is equal to the number of flat tubes (53) of the main heat exchange unit (50). Less than. The total cross-sectional area of the flow path (49) per one flat tube (58) provided in the auxiliary heat exchange part (55) is equal to one flat tube (53) provided in the main heat exchange part (50). It is formed larger than the total cross-sectional area of the perimeter flow path (49).

In this example, the outdoor heat exchanger (40) can be provided with 60 flat tubes (53, 58). The number of flat tubes (58) in the auxiliary heat exchange section (55) is 10, and the number of flat tubes (53) in the main heat exchange section (50) is 50. That is, the number of flat tubes (58) of the auxiliary heat exchange section (55) is 1/5 of the number of flat tubes (53) of the main heat exchange section (50). The number of flat tubes (53,58) shown in FIGS. 3 and 4 is different from the number of flat tubes (53,58) provided in the actual outdoor heat exchanger (40).

As described above, in the refrigerant circuit (20), the first gas side pipe (21) is at the upper end of the first header member (46), and the liquid side pipe (23) is at the lower end of the first header member (46). Are connected to each other (see FIG. 1). That is, in the outdoor heat exchanger (40), the first gas side pipe (21) is connected to the first header collecting pipe (51) of the main heat exchanging part (50), and the first header set of the auxiliary heat exchanging part (55). A liquid side pipe (23) is connected to the pipe (56).

<Driving operation>
The operation of the air conditioner (10) will be described. The air conditioner (10) performs a cooling operation that is a cooling operation and a heating operation that is a heating operation.

<Cooling operation>
The operation of the air conditioner (10) during the cooling operation will be described with reference to FIG.

During the cooling operation, the four-way selector valve (34) is set to the first state. The opening degree of the expansion valve (33) is adjusted so that the degree of superheat of the refrigerant flowing out from the gas side end of the indoor heat exchanger (32) becomes a predetermined target value (for example, 5 ° C.). Further, during the cooling operation, outdoor air is supplied to the outdoor heat exchanger (40) by the outdoor fan, and indoor air is supplied to the indoor heat exchanger (32) by the indoor fan.

In the refrigerant circuit (20), the refrigerant discharged from the compressor (31) sequentially passes through the four-way switching valve (34) and the first gas side pipe (21), and then passes through the first heat exchanger (50). 1 flows into the header collecting pipe (51). The refrigerant that has flowed into the first header collecting pipe (51) is divided into the flat pipes (53) of the main heat exchange section (50) and flows through the refrigerant flow paths (49) of the flat pipes (53). In the meantime, it dissipates heat to the outdoor air and condenses. The refrigerant that has passed through each flat tube (53) flows into and merges with the second header collecting pipe (52) of the main heat exchange section (50), and then the second header collecting pipe ( 57). The refrigerant that has flowed into the second header collecting pipe (57) is divided into the flat pipes (58) of the auxiliary heat exchange section (55) and flows through the refrigerant flow paths (49) of the flat pipes (58). In the meantime, heat is dissipated to the outdoor air and it becomes supercooled. The refrigerant that has passed through each flat tube (58) flows into and merges with the first header collecting tube (56) of the auxiliary heat exchange section (55).

The refrigerant flowing into the liquid side pipe (23) from the first header collecting pipe (56) of the auxiliary heat exchanger (55) expands (pressure drop) when passing through the expansion valve (33), and then the indoor heat exchanger. It flows into the liquid side end of (32). The refrigerant flowing into the indoor heat exchanger (32) absorbs heat from the indoor air and evaporates. The indoor unit (12) supplies the sucked room air to the indoor heat exchanger (32), and sends the room air cooled in the indoor heat exchanger (32) back into the room.

The refrigerant evaporated in the indoor heat exchanger (32) flows into the second gas side pipe (22) from the gas side end of the indoor heat exchanger (32). Thereafter, the refrigerant is sucked into the compressor (31) through the four-way switching valve (34). The compressor (31) compresses the sucked refrigerant and discharges it.

<Heating operation>
The operation of the air conditioner (10) during the heating operation will be described with reference to FIG.

During the heating operation, the four-way selector valve (34) is set to the second state. The opening degree of the expansion valve (33) is adjusted so that the degree of superheat of the refrigerant flowing out from the outdoor heat exchanger (40) becomes a predetermined target value (for example, 5 ° C.). Further, during the heating operation, outdoor air is supplied to the outdoor heat exchanger (40) by the outdoor fan, and indoor air is supplied to the indoor heat exchanger (32) by the indoor fan.

In the refrigerant circuit (20), the refrigerant discharged from the compressor (31) sequentially passes through the four-way switching valve (34) and the second gas side pipe (22), and then the gas in the indoor heat exchanger (32). It flows into the side edge. The refrigerant flowing into the indoor heat exchanger (32) dissipates heat to the indoor air and condenses. The indoor unit (12) supplies the sucked indoor air to the indoor heat exchanger (32), and sends the indoor air heated in the indoor heat exchanger (32) back into the room.

The refrigerant flowing into the liquid side pipe (23) from the liquid side end of the indoor heat exchanger (32) expands (pressure drop) when passing through the expansion valve (33), and then enters the auxiliary heat exchanger (55). It flows into the first header collecting pipe (56). The refrigerant that has flowed into the first header collecting pipe (56) of the auxiliary heat exchange section (55) is divided and flows into the flat pipe (58) of the auxiliary heat exchange section (55). The refrigerant flowing into the flat tube (58) absorbs heat from the outdoor air while passing through the refrigerant flow path (49), and part of it evaporates. The refrigerant evaporated in the flat pipe (58) flows into the second header collecting pipe (52), and flows into the flat pipe (53) of the main heat exchange section (50). The refrigerant flowing into the flat tube (53) absorbs heat from the outdoor air and evaporates while passing through the refrigerant flow path (49).

The refrigerant that has passed through each flat tube (53) of the main heat exchange section (50) flows into and merges with the first header collecting pipe (51) of the main heat exchange section (50), and then the first gas side pipe It flows into (21). The refrigerant flowing through the first gas side pipe (21) passes through the four-way switching valve (34) and is sucked into the compressor (31). The compressor (31) compresses the sucked refrigerant and discharges it.

<Effect in this embodiment>
In the present embodiment, the number of flat tubes (58) constituting the auxiliary heat exchange section (55) is smaller than the number of flat tubes (53) constituting the main heat exchange section (50). However, the total cross-sectional area of the flow path (49) per one flat tube (58) provided in the auxiliary heat exchanger (55) is equal to one flat tube (53) provided in the main heat exchanger (50). ) Larger than the total cross-sectional area of the channel (49). Therefore, when the heat exchanger is a condenser, for example, a heat exchanger in which a main heat exchange unit and an auxiliary heat exchange unit are configured by one type of flat tube (hereinafter, for convenience of explanation, a conventional heat exchanger and The refrigerant flow rate in the auxiliary heat exchanging section (55) can be made slower than that of the auxiliary heat exchange section (55). Therefore, according to the present embodiment, it is possible to reduce the pressure loss in the auxiliary heat exchange section (55).

In the present embodiment, the number of flow paths per one flat pipe (53,58) and the width (W1, W2) are adjusted, and the refrigerant flow path (49 per one flat pipe (53,58)). ) Total cross section is set. Therefore, the total cross-sectional area of the refrigerant flow path (49) in the flat tube (53) for the main heat exchange section (50) and the refrigerant flow path (49) in the flat pipe (58) for the auxiliary heat exchange section (55) The total cross-sectional area can be set easily.

In the present embodiment, each refrigerant flow path (49) of the flat tube (53) in the main heat exchange section (50) is provided with a groove (49a). Therefore, in the flat tube (53), the surface area per refrigerant channel (49) can be increased. That is, it becomes possible to improve the heat exchange efficiency in the main heat exchange section (50).

Moreover, since the flat tube (58) of the auxiliary heat exchanger (55) is a so-called bare tube, the pressure loss due to the shape can be made smaller than the flat tube (53) of the main heat exchanger (50). It becomes possible.

In addition, since the refrigerant flow path (49) has a very small diameter as described above, when the outdoor heat exchanger (40) is manufactured at the factory, for example, a flat pipe having the same width is used as the main heat exchange section. If the auxiliary heat exchange part is configured, it is difficult to visually identify the presence or absence of the groove (49a) in the refrigerant flow path (49). However, in this embodiment, the flat tubes (53) for the main heat exchange section (50) and the flat tubes (58) for the auxiliary heat exchange section (55) have different widths (W1, W2). The presence or absence of the groove (49a) in the flow path (49) can be easily identified.

<< Variation 1 of Embodiment 1 >>
In addition, the structure of a fin (54,59) is an illustration, and it is possible to employ | adopt a various fin for a heat exchanger (40). For example, instead of the fins (54, 59), it is possible to employ the fins shown in FIG. FIG. 8 is a diagram illustrating a part of a cross section of the heat exchanger (40) according to the first modification of the first embodiment. The fins (235) are corrugated fins meandering up and down, and are arranged between flat tubes (53, 58) (heat transfer tubes) adjacent to each other in the vertical direction. As will be described in detail later, a plurality of heat transfer sections (237) and intermediate plate sections (241) are formed on the fin (235). In each fin (235), the intermediate plate (241) is joined to the flat tube (53, 58) by brazing.

<Fin configuration>
FIG. 9 is a schematic perspective view of the fin (235) provided in the heat exchanger (40) of the first modification. As shown in FIG. 9, the fin (235) is a corrugated fin formed by bending a metal plate having a constant width, and has a shape meandering up and down. In the fin (235), heat transfer portions (237) and intermediate plate portions (241) are alternately formed along the extending direction of the flat tubes (53, 58). That is, the fin (235) is provided with a plurality of heat transfer portions (237) arranged between the adjacent flat tubes (53, 58) and arranged in the extending direction of the flat tubes (53, 58). The fin (235) is formed with a protruding plate portion (242). In FIG. 9, louvers (250, 260, 270) and a water guiding rib (271) described later are not shown.

The heat transfer portion (237) is a plate-like portion extending from one side of the flat tube (53, 58) adjacent to the top and bottom to the other. In the heat transfer section (237), the windward end is the leading edge (238). Although not shown in FIG. 9, a plurality of louvers (250, 260) are formed in the heat transfer section (237). The intermediate plate portion (241) is a plate-like portion along the flat side surface of the flat tube (53,58), and is continuous with the upper ends or lower ends of the heat transfer portions (237) adjacent to the left and right. Yes. The angle formed by the heat transfer section (237) and the intermediate plate section (241) is substantially a right angle.

The protruding plate portion (242) is a plate-like portion formed continuously at the leeward end of each heat transfer portion (237). The projecting plate portion (242) is formed in an elongated plate shape extending vertically and projects further to the leeward side than the flat tube (53, 58). Further, the upper end of the protruding plate portion (242) protrudes above the upper end of the heat transfer portion (237), and the lower end protrudes below the lower end of the heat transfer portion (237). As shown in FIG. 8, in the heat exchanger (40), the protruding plate portions (242) of the fins (235) that are adjacent vertically with the flat tubes (53, 58) interposed therebetween contact each other. The projecting plate portion (242) of the fin (235) is formed with a water guiding rib (271). The water guiding rib (271) is a long and narrow groove extending vertically along the leeward side end portion of the protruding plate portion (242).

FIG. 10 is a view showing the heat transfer section (237) provided on the fin (235) of the heat exchanger (40) of Modification 1, and (A) is a front view of the heat transfer section, B) is a sectional view showing a BB section of (A). As shown in FIG. 10, a plurality of louvers (250, 260, 270) are formed on the heat transfer section (237) and the protruding plate section (242) of the fin (235). Each louver (250, 260, 270) is formed by cutting and raising the heat transfer part (237) and the protruding plate part (242). In other words, each louver (250, 260, 270) is formed by making a plurality of slit-like cuts in the heat transfer part (237) and the protruding plate part (242) and plastically deforming so as to twist the part between the adjacent cuts. ing.

<< Modification 2 of Embodiment 1 >>
FIG. 11A is a cross-sectional view of a part of the heat exchanger 40 according to the second modification, and FIG. 11B is a cross-sectional view of the fin showing the VV cross section of FIG. 11A. . In this example, a plurality of waffle portions (251, 252 and 253) are formed instead of the louvers (250, 260 and 270) shown in the first modification. As shown in FIG. 11, a plurality of waffle portions (251, 252, 253) are formed on the heat transfer portion (237) and the protruding plate portion (242) of the fin (235). The waffle portion (251, 252, 253) bulges toward the side that becomes the ventilation path, and constitutes a bulge portion that is vertically formed vertically. The waffle part (251, 252, 253) is formed by plastically deforming a part of the heat transfer part (237) by press working or the like. Each waffle portion (251, 252, 253) extends in a direction inclined obliquely with respect to the vertical direction so that its lower end portion is located closer to the lee than the upper end portion.

Each waffle part (251,252,253) has a pair of vertically long trapezoidal surfaces (254,254) and a pair of flat triangular surfaces (255,255) vertically. The pair of trapezoidal surfaces (254, 254) are adjacent to each other in the ventilation direction so as to form a mountain fold (256) forming a ridge line between them. The pair of triangular surfaces (255, 255) are formed up and down across the mountain fold (256).

In the heat transfer section (237), a plurality of waffle sections (251, 252 and 253) are formed side by side from the leeward side to the leeward side. These waffle parts (251, 252 and 253) are composed of one windward waffle part (251) formed on the leeward side of the heat transfer part (237) and two leeward sides formed on the leeward side of the heat transfer part (237). The waffle portion (253, 253) and one intermediate waffle portion (252) formed between the windward waffle portion (251) and the leeward waffle portion (253) are configured. The windward waffle portion (251) constitutes the windward bulge portion formed on the most windward side among the plurality of waffle portions (251, 252, 253). The leeward waffle portion (253,253) constitutes the leeward bulge portion formed on the most leeward side among the plurality of waffle portions (251,252,253).

The upper end of the leeward waffle part (251) is lower than the upper end of the leeward waffle part (253). Further, the upper end of the intermediate waffle portion (252) and the upper end of the leeward waffle portion (253) are substantially at the same height. The upper end of the windward waffle portion (251), the upper end of the intermediate waffle portion (252), and the upper end of the leeward waffle portion (253) are substantially parallel to the flat surface of the upper flat tube (53,58). .

The lower end of the leeward waffle part (251) is higher than the lower end of the leeward waffle part (253). The lower end of the windward waffle portion (251) is inclined obliquely so that the leeward side is lower than the windward side. The lower end of the intermediate waffle portion (252) is also inclined obliquely so that the leeward side is lower than the leeward side. The lower end of the leeward waffle portion (253) is substantially parallel to the flat surface of the flat tube (53, 58).

<< Modification 3 of Embodiment 1 >>
Instead of the above fins (54, 59), it is possible to employ the fins shown in FIG. FIG. 12 is a diagram illustrating a part of a cross section of the heat exchanger (40) according to the third modification of the first embodiment.

<Fin configuration>
As shown in FIG. 12, the fin (236) is a vertically long plate-like fin formed by pressing a metal plate. The fin (236) is formed with a number of elongated notches (245) extending in the width direction of the fin (236) from the front edge (238) of the fin (236). In the fin (236), a large number of notches (245) are formed at regular intervals in the longitudinal direction of the fin (236). The portion closer to the lee of the notch (245) constitutes the tube insertion portion (246). The tube insertion portion (246) has a vertical width substantially equal to the thickness of the flat tube (53, 58). Further, the length (depth) of the tube insertion portion (246) is substantially equal to the width of the flat tube (58) having the wider width. Thus, the type of the fin (236) can be made one by matching the depth of the tube insertion portion (246) with the width of the flat tube (58) having the wider width. That is, it is not necessary to prepare a plurality of types of molds for manufacturing the fin (236), and a reduction in manufacturing cost can be expected. Each flat tube (53, 58) is inserted into the tube insertion portion (246) of the fin (236) and joined to the peripheral portion of the tube insertion portion (246) by brazing. In the present embodiment, the ends in the width direction of the flat tubes (53, 58) are aligned with the ends on the entrance side of the notches (245). Since the length of the tube insertion portion (246) is adjusted to the width (W2) of the flat tube (58), the tube insertion portion (246) is inserted into the tube insertion portion (246) into which the flat tube (53) is inserted. There will be a gap in the back of the.

The brazing of the fin (236) and the flat tube (53, 58) is performed as follows, for example. First, the notch (245) side (left side in FIG. 12) of the fin (236) is faced up, and the end of the flat tube (53,58) in the width direction is more specifically the entrance side of the notch (245). Are set to be aligned with the inlet end (left end in FIG. 12) of the tube insertion portion (246). As the brazing material, a linear material is placed at the position (A) shown in FIG. In FIG. 12, the installation position (A) is representatively shown only for one flat tube (53), but the same applies to the other flat tubes (53, 58). When the heat transfer tube (53) is applied to the innermost part of the tube insertion portion (246), the brazing material is dropped into the tube insertion portion (246) during brazing, and it is difficult to set. However, in the present embodiment, as described above, the end in the width direction of the flat tube (53, 58) is aligned with the end on the entrance side of the notch (245), so the brazing material can be easily set. is there.

Then, for example, the heat exchanger (40) is placed in a heating furnace (not shown) to melt the brazing material. Thereby, the brazing material flows along the flat tube (53, 58), and the fin (236) and the flat tube (53, 58) are joined.

In the fin (236), the part between the adjacent notches (245) constitutes the heat transfer part (237), and the leeward part of the pipe insertion part (246) constitutes the leeward side plate part (247). ing. That is, the fin (236) is connected to a plurality of heat transfer portions (237) that are vertically adjacent to each other with the flat tube (53, 58) interposed therebetween, and one end that is continuous to the leeward end of each heat transfer portion (237). Two leeward side plate portions (247) are provided. In this heat exchanger (40), the heat transfer parts (237) of the fins (236) are arranged between the flat tubes (53, 58) lined up and down, and the leeward plate (247) is connected to the flat tubes (53, 58). It protrudes leeward from 58).

FIG. 13: is a figure which shows the principal part of the fin (236) of the heat exchanger (40) of the modification 3, Comprising: (A) is a front view of a fin (236), (B) is (A). It is sectional drawing which shows the GG cross section. As shown in FIG. 13, a plurality of louvers (250, 260) are formed on the heat transfer section (237) and the leeward side plate section (247) of the fin (236). Each louver (250, 260) is formed by cutting up the heat transfer section (237) and the leeward side plate section (247).

<< Modification 4 of Embodiment 1 >>
FIG. 14A is a cross-sectional view of a part of the heat exchanger (40) of Modification 4, and FIG. 14 (B) is a cross-section of the fin (236) showing the XX cross-section of FIG. 14 (A). FIG. In this example, waffle portions (251, 252 and 253) are formed on the plate-like fins described in the third modification instead of the louvers (250 and 260). These waffle portions (251, 252, 253) have the same configuration as that described in the second modification.

<< Embodiment 2 of the Invention >>
The outdoor heat exchanger of Embodiment 2 of invention is demonstrated. FIG. 15 is a front view illustrating a schematic configuration of the outdoor heat exchanger (40) of the second embodiment. FIG. 16 is a partial cross-sectional view showing the front of the outdoor heat exchanger (40) of the second embodiment.

As shown in FIG. 15, the outdoor heat exchanger (40) is divided into three heat exchange sections (350a to 350c). Specifically, the outdoor heat exchanger (40) 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. 16, each of the first header collecting pipe (360) and the second header collecting pipe (370) 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 first header collecting pipe (360) are further partitioned vertically by a partition plate (339). In each communication space (361a to 361c) of the first header collecting pipe (360), 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 section (350a to 350c) of the outdoor heat exchanger (40) has a main heat exchange area (351a to 351c) (main heat exchange section) and an auxiliary heat exchange area (352a to 352c) (auxiliary heat exchange section). It is divided into. In each heat exchange section (350a to 350c), eleven flat tubes (53) communicating with the upper partial spaces (363a to 363c) of the corresponding first header collecting pipe (360) are the main heat exchange sections (351a to 350c). 351c), and the three flat tubes (58) communicating with the lower partial spaces (362a to 362c) of the corresponding first header collecting pipe (360) constitute the auxiliary heat exchange section (352a to 352c). ing.

Also in this embodiment, as in the first embodiment, the width of the flat tube (58) provided in each auxiliary heat exchange section (352a to 352c) is provided in the main heat exchange section (351a to 351c). The number of channels per flat tube (58) provided in the auxiliary heat exchange section (352a to 352c) is larger than the width of the flat pipe (53), and is provided in the main heat exchange section (351a to 351c). More than the number of channels per flat tube (53). In this example, fins (235) (corrugated fins) are employed as the fins. Of course, it is possible to employ the fins (54, 59) of the first embodiment and the fins (236) described in other modifications.

As shown in FIG. 15, the outdoor heat exchanger (40) is provided with a liquid side connecting member (380) and a gas side header (385). The liquid side connection member (380) and the gas side header (385) are attached to the first header collecting pipe (360).

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 (40) and the expansion valve (33) is connected to the lower end of the flow divider (381). One end of each small diameter tube (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 communicates with the small diameter pipes (382a to 382c). The other end of each small diameter pipe (382a to 382c) is connected to the first header collecting pipe (360) 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 (40) and the third port of the four-way switching valve (34) 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 (40) of the present embodiment, the refrigerant flows in the direction of the arrow shown in FIG. 15 during the cooling operation. Further, during the heating operation, the refrigerant flows in the direction opposite to the arrow shown in FIG.

<< Embodiment 3 of the Invention >>
The outdoor heat exchanger of Embodiment 3 of invention is demonstrated. FIG. 17 is a front view illustrating a schematic configuration of the outdoor heat exchanger (40) of the third embodiment. FIG. 18 is a partial cross-sectional view showing the front of the outdoor heat exchanger (40) of the third embodiment.

As shown in FIGS. 17 and 18, the outdoor heat exchanger (40) includes one first header collecting pipe (460), one second header collecting pipe (470), and a number of flat tubes (53, 53). 58) and a number of fins (235).

As shown in FIG. 17, the flat tubes (53, 58) of the outdoor heat exchanger (40) are divided into two heat exchange regions (451, 452) in the vertical direction. That is, the outdoor heat exchanger (40) has an upper heat exchange region (451) and a lower heat exchange region (452). Each heat exchanging region (451, 452) is divided into three upper and lower 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. As described above, in the outdoor heat exchanger (40) 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. 18, each main heat exchange section (451a to 451c) has eleven flat tubes (53), and each auxiliary heat exchange section (452a to 452c) has three flat tubes ( 58). The number of heat exchanging portions (451a to 451c, 452a to 452c) formed in each heat exchanging region (451, 452) may be two, or four or more.

Also in this embodiment, as in the first embodiment, the width of the flat tube (58) provided in each auxiliary heat exchange section (452a to 452c) is provided in the main heat exchange section (451a to 451c). The number of channels per flat tube (58) that is larger than the width of the flat tube (53) and is provided in the auxiliary heat exchanger (452a to 452c) is provided in the main heat exchanger (451a to 451c). More than the number of channels per flat tube (53).

The internal space of the first header collecting pipe (460) and the second header collecting pipe (470) is partitioned vertically by a plurality of partition plates (439).

Specifically, the internal space of the first header collecting pipe (460) 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) in common. That is, the upper space (461) communicates with the flat tubes (53) of all the main heat exchange sections (451a to 451c). The lower space (462) is further divided by a 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). That is, in the lower space (462), the first communication space (462a) communicating with the flat tube (58) of the first auxiliary heat exchange section (452a), and the flat tube of the second auxiliary heat exchange section (452b) ( 58) and a second communication space (462b) communicating with the flat tube (58) of the third auxiliary heat exchange section (452c) are formed.

The internal space of the second header collecting pipe (470) is divided into five communication spaces (471a to 471e) in the vertical direction. Specifically, the inner space of the second header collecting pipe (470) is the uppermost in the first main heat exchanging portion (451a) and the lower heat exchanging region (452) located at the lowermost position in the upper heat exchanging region (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 second header collecting pipe (470), the first communication space (471a) communicating with the flat pipe (58) of the first auxiliary heat exchange section (452a) and the second auxiliary heat exchange section (452b). ) Communicated with the second communication space (471b) communicating with the flat tube (58) and the flat tubes (53,58) of both the third auxiliary heat exchange section (452c) and the first main heat exchange section (451a). The third communication space (471c), the fourth communication space (471d) communicating with the flat tube (53) of the second main heat exchanging portion (451b), and the flat tube of the third main heat exchanging portion (451c) ( 53) and a fifth communication space (471e) that communicates with each other.

In the second header collecting pipe (470), 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 second header collecting pipe (470) 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 second communication space. A second communication pipe (473) that connects the five communication spaces (471e) is provided. That is, in the outdoor heat exchanger (40) 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. The number of heat exchange units (451a to 451c, 452a to 452c) formed in the outdoor heat exchanger (40) 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 (40) so as to be approximately 350 mm or less (preferably about 300 to 350 mm).

Thus, in the internal space of the second header collecting pipe (470), 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 exchange portions (452a to 452c) corresponding to the auxiliary heat exchange portions (452a to 452c) of the lower heat exchange 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. 17, the outdoor heat exchanger (40) 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 first header collecting pipe (460).

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 (40) and the expansion valve (33) 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 first header collecting pipe (460) and communicates with the corresponding communication space (462a to 462c).

As shown also in FIG. 18, each small-diameter pipe (482a to 482c) opens in a portion near the lower end of the corresponding communication space (462a to 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). The lengths of the small diameter tubes (482a to 482c) are individually set so that the difference in the flow rate of the refrigerant flowing into the auxiliary heat exchange units (452a to 452c) is as small as possible.

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 (40) and the third port of the four-way switching valve (34). 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 first header collecting pipe (460).

With the above configuration, in the outdoor heat exchanger (40) of the present embodiment, the refrigerant flows in the direction of the arrow shown in FIG. 17 during the cooling operation. Further, during the heating operation, the refrigerant flows in the direction opposite to the arrow shown in FIG.

<< Embodiment 4 of the Invention >>
The outdoor heat exchanger of Embodiment 4 of invention is demonstrated. FIG. 19 is a front view illustrating a schematic configuration of the outdoor heat exchanger (40) of the fourth embodiment. FIG. 20 is a partial cross-sectional view showing the front of the outdoor heat exchanger (40) of the fourth embodiment.

As shown in FIG. 19, the flat tubes (53, 58) of the outdoor heat exchanger (40) have an upper heat exchanging region (451) and a lower heat exchanging region (452) vertically as in the third embodiment. It is divided into. The upper heat exchange area (451) is divided into three main heat exchange sections (451a to 451c) arranged vertically, and the lower heat exchange area (452) is composed of one auxiliary heat exchange section (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 FIG. 20, each main heat exchange section (451a to 451c) has eleven flat tubes (53), and the auxiliary heat exchange section (452a) has nine flat tubes (58). Have. Note that the number of main heat exchange portions (451a to 451c) formed in the upper heat exchange region (451) may be two, or may be four or more.

The internal space of the first header collecting pipe (460) and the second header collecting pipe (470) is divided up and down by a partition plate (439).

Also in the present embodiment, as in the first embodiment, the flat tubes (58) provided in the respective auxiliary heat exchange sections (452a) have the same width as the flat tubes provided in the main heat exchange sections (451a to 451c). The number of flow paths per flat tube (58) provided in the auxiliary heat exchange section (452a) is larger than the width of (53), and the number of flow paths per flat pipe provided in the main heat exchange sections (451a to 451c) More than the number of channels per tube (53).

Specifically, the internal space of the first header collecting pipe (460) 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) in common. That is, the upper space (461) communicates with the flat tubes (53) of all the main heat exchange sections (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 (58) of the auxiliary heat exchange part (452a). ing.

The internal space of the second header collecting pipe (470) is divided into four communication spaces (471a to 471d) in the vertical direction. Specifically, the internal space of the second header collecting pipe (470) 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 second header collecting pipe (470), the first communication space (471a) communicating with the flat pipe (58) 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 (53), a third communication space (471c) communicating with the flat tube (53) 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 (53) of (451c) is formed.

The second header collecting pipe (470) is provided with a communication member (475). 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 second header collecting pipe (470). One end of each small diameter pipe (478a to 478c) is connected to the upper end of the flow divider (476). Inside the shunt (481), 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 second header collecting tube (470).

As shown in FIG. 20, each small-diameter pipe (478a to 478c) is opened in 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). The lengths of the small diameter tubes (478a to 478c) are individually set so that the difference in the flow rate of the refrigerant flowing into the main heat exchange sections (451a to 451c) becomes as small as possible. As described above, the communication member (475) of the second header collecting pipe (470) 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 second header collecting pipe (470), 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. 19, the outdoor heat exchanger (40) 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 first header collecting pipe (460). The liquid side connection member (486) is composed of a single pipe having a relatively large diameter. One end of the liquid side connection member (486) is connected to a pipe connecting the outdoor heat exchanger (40) and the expansion valve (33). The other end of the liquid side connection member (486) is opened in a portion near the lower end of the lower space (462) (communication space (462a)) in the first header collecting pipe (460). 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 (40) and the third port of the four-way switching valve (34). 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 first header collecting pipe (460).

With the above configuration, in the outdoor heat exchanger (40) of the present embodiment, the refrigerant flows in the direction of the arrow shown in FIG. 19 during the cooling operation. Further, during the heating operation, the refrigerant flows in the direction opposite to the arrow shown in FIG.

<< Embodiment 5 of the Invention >>
Embodiment 5 of the present invention will be described. The present embodiment is obtained by changing the configuration of the second header collecting pipe (470) in the outdoor heat exchanger (40) of the third embodiment, and the other configurations are the same as those of the third embodiment. In the present embodiment, only the configuration of the second header collecting pipe (470) of the outdoor heat exchanger (40) will be described with reference to FIGS. 21 and 22 as appropriate.

FIG. 21 is a front view showing a schematic configuration of the outdoor heat exchanger (40) of the fifth embodiment. FIG. 22 is a partial cross-sectional view showing the front of the outdoor heat exchanger (40) of the fifth embodiment. As shown in FIG. 22, the internal space of the second header collecting pipe (470) of the outdoor heat exchanger (40) is divided into three communication spaces (471a to 471c) on the left and right by two partition plates (439). ing. Specifically, in the inner space of the second header collecting pipe (470), a first communication space (471a), a second communication space (471b), and a third communication space (471c) are formed in order from the right side in FIG. ing. The first communication space (471a) communicates with the flat tube (53) of the third main heat exchange unit (451c) and the end of the flat tube (58) of the first auxiliary heat exchange unit (452a). The second communication space (471b) communicates with the flat tube (53) of the second main heat exchange unit (451b) and the end of the flat tube (58) of the second auxiliary heat exchange unit (452b). The third communication space (471c) communicates with the flat tube (53) of the first main heat exchange unit (451a) and the end of the flat tube (58) of the third auxiliary heat exchange unit (452c). In the outdoor heat exchanger (40), the third main heat exchange part (451c) and the first auxiliary heat exchange part (452a) are paired, and the second main heat exchange part (451b) and the second auxiliary heat exchange part (452b) ) As a pair, and the first main heat exchange part (451a) and the third auxiliary heat exchange part (452c) form a pair.

That is, the second header collecting pipe (470) in the outdoor heat exchanger (40) of the present embodiment includes the main heat exchange units (451a to 451c) in the upper heat exchange region (451) and the lower heat exchange region ( 452), each auxiliary heat exchanging part (452a to 452c) is paired with each other, and a single communication space (45a to 451c, 452a to 452c) corresponding to the two common heat exchanging parts (451a to 451c) 471a to 471c) are formed in the same number (three) as the number of pairs. In this way, in the second header collecting pipe (470), the flat pipes (53,58) of the main heat exchange sections (451a to 451c) and the auxiliary heat exchange sections (452a) that form a pair are the second header set. It communicates directly in the internal space of the tube (470).

With the above configuration, in the outdoor heat exchanger (40) of the present embodiment, the refrigerant flows in the direction of the arrow shown in FIG. 21 during the cooling operation. Further, during the heating operation, the refrigerant flows in the direction opposite to the arrow shown in FIG.

Embodiment 6 of the Invention
Embodiment 6 of the present invention will be described. In the present embodiment, the configuration of the outdoor heat exchanger (40) of the third embodiment is changed. Here, about the outdoor heat exchanger (40) of this embodiment, a different point from the said Embodiment 3 is demonstrated, referring FIG.23 and FIG.24 suitably.

The internal space of the second header collecting pipe (470) of the present embodiment is partitioned into five communication spaces (471a to 471e) in the vertical direction as in the third embodiment. In the second header collecting pipe (470) of the present embodiment, the first communication space (471a) and the fifth communication space (471e) are paired, and the second communication space (471b) and the fourth communication space (471d). Are paired. The second header collecting pipe (470) includes a first communication pipe (472) connecting the second communication space (471b) and the fourth communication space (471d), a first communication space (471a), and a second communication space. A second communication pipe (473) that connects the five communication spaces (471e) is provided. That is, in the outdoor heat exchanger (40) 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 second The auxiliary heat exchange part (452b) is a pair, and the third main heat exchange part (451c) and the first auxiliary heat exchange part (452a) are a pair.

Further, in the outdoor heat exchanger (40) of the present embodiment, the connection position of the gas side connection member (485) in the first header collecting pipe (460) is changed. Specifically, the gas side connection member (485) opens in a central portion (center in the vertical direction) of the upper space (461) in the first header collecting pipe (460). Furthermore, as shown in FIG. 24, in the outdoor heat exchanger (40) of the present embodiment, the inner diameter B1 of the first header collecting pipe (460) is larger than the inner diameter B2 of the second header collecting pipe (470). With this configuration, the gas refrigerant flowing from the gas side connection member (485) into the upper space (461) of the first header collecting pipe (460) is evenly distributed to the three main heat exchange parts (451a to 451c). Can be shunted.

In the outdoor heat exchanger (40) of the present embodiment, the inner diameters of the two header collecting pipes (460, 470) may be the same, and the gas side connection member (485) is used as the first header collecting pipe (460). You may make it open in the part near the upper end of upper side space (461).

<< Embodiment 7 of the Invention >>
FIG. 25 is a diagram illustrating a part of a cross section of the outdoor heat exchanger (40) of the seventh embodiment. In the present embodiment, the width of the flat tube (53) of the main heat exchange part (50) and the width of the flat tube (58) of the auxiliary heat exchange part (55) are the same. As in the previous embodiment, the number of flat tubes (58) in the auxiliary heat exchange section (55) is smaller than the number of flat tubes (53) in the main heat exchange section (50). And the total cross-sectional area of the refrigerant | coolant flow path (49) per one flat tube (58) provided in the auxiliary heat exchange part (55) is one flat tube ( It is larger than the total cross-sectional area of the refrigerant flow path (49) per 53). In this embodiment, although not shown in FIG. 25, the aforementioned bare pipe (inner surface smooth pipe, see FIG. 7B) is adopted for the flat pipe (53) of the main heat exchange section (50). Each refrigerant channel (49) has a circular cross section. On the other hand, the flat tube (58) of the auxiliary heat exchange section (55) has a plurality of grooves formed in the respective refrigerant flow paths (49) (see FIG. 7A). Even in this configuration, it is possible to reduce the flow rate of the refrigerant in the auxiliary heat exchange section (55). Therefore, also in this embodiment, it becomes possible to reduce the pressure loss in the auxiliary heat exchange section (55).

<< Embodiment 8 of the Invention >>
Also in the outdoor heat exchanger (40) of Embodiment 8, the width of the flat tube (53) of the main heat exchange part (50) and the width of the flat tube (58) of the auxiliary heat exchange part (55) are the same. . Further, the number of flat tubes (58) in the auxiliary heat exchange section (55) is smaller than the number of flat tubes (53) in the main heat exchange section (50).

And the total cross-sectional area of the refrigerant | coolant flow path (49) per one flat tube (58) provided in the auxiliary heat exchange part (55) is one flat tube ( It is larger than the total cross-sectional area of the refrigerant channel (49) per 53). Specifically, the number of refrigerant flow paths (49) in the flat tube (53) of the main heat exchange section (50) is determined from the number of refrigerant flow paths (49) in the flat pipe (58) of the auxiliary heat exchange section (55). Less. Even in this configuration, it is possible to reduce the flow rate of the refrigerant in the auxiliary heat exchange section (55). Therefore, also in this embodiment, it becomes possible to reduce the pressure loss in the auxiliary heat exchange section (55). In addition, the refrigerant | coolant flow path (49) of each heat exchanger tube (53,58) in a main heat exchange part (50) and an auxiliary heat exchange part (55) may be provided with a groove | channel (FIG. 7 (A) and (B)).

In addition, in each outdoor heat exchanger (40) of Embodiments 2 to 8, various fins such as the fins (54, 59, 235, 236) described in Embodiment 1 and its modifications can be adopted.

The present invention includes a flat tube and fins, and is useful as a heat exchanger and an air conditioner for exchanging heat between fluid flowing in the flat tube and air.

10 Air conditioner 40 Outdoor heat exchanger (heat exchanger)
49 Refrigerant flow path (flow path)
50

Main heat exchanger

51, 56 First

header collecting pipe

52, 57 Second header collecting pipe 53

Flat pipe

54, 59 Fin 55 Auxiliary heat exchanging section 58 Flat pipe

Claims

Between a plurality of flat tubes (53,58) in which a plurality of fluid flow paths (49) are formed inside, and the adjacent flat tubes (53,58) arranged side by side so as to face each other A heat exchanger comprising a plurality of fins (54, 59) partitioned into a plurality of ventilation paths through which air flows,
A first header collecting pipe (51, 56);
A second header collecting pipe (52, 57),
Each of the flat tubes (53, 58) has one end connected to the first header collecting pipe (51, 56) and the other end connected to the second header collecting pipe (52, 57).
Some flat tubes (53) of the plurality of flat tubes (53,58) constitute the main heat exchange part (50), and the remaining flat tubes (58) constitute the auxiliary heat exchange part (55). And
The number of flat tubes (58) constituting the auxiliary heat exchange section (55) is less than the number of flat tubes (53) constituting the main heat exchange section (50),
The total cross-sectional area of the flow path (49) per flat pipe (58) in the auxiliary heat exchange section (55) is the flow path per flat pipe (53) in the main heat exchange section (50) ( 49) greater than the total cross-sectional area of
When the heat exchanger is a condenser, the refrigerant is condensed in the main heat exchange section (50), and the refrigerant is supercooled in the auxiliary heat exchange section (55). .
The heat exchanger of claim 1,
The width (W2) of the flat tube (58) of the auxiliary heat exchanger (55) is larger than the width (W1) of the flat tube (53) of the main heat exchanger (50),
The number of flow paths per flat tube (58) of the auxiliary heat exchange section (55) is larger than the number of flow paths per flat pipe (53) of the main heat exchange section (50). Heat exchanger.
The heat exchanger according to claim 1 or 2,
A plurality of grooves are formed in the flow path (49) of the flat tube (53) of the main heat exchange part (50),
The flat tube (58) of the auxiliary heat exchanging section (55) is a bare tube.
The heat exchanger according to any one of claims 1 to 3,
The fins (236) are formed in a plate shape provided with a plurality of notches (245) for inserting the flat tubes (53, 58), and are predetermined to each other in the extending direction of the flat tubes (53, 58). The flat tube (53,58) is sandwiched at the periphery of the notch (245),
In the fin (236), the heat exchanger (237) is characterized in that the portion between the upper and lower cutouts (245) constitutes a heat transfer section (237).
The heat exchanger according to claim 4,
An end of the flat tube (53, 58) in the width direction is aligned with an end of the notch (245) on the entrance side.
A refrigerant circuit (20) provided with the heat exchanger (40) according to any one of claims 1 to 5,
An air conditioner that performs a refrigeration cycle by circulating refrigerant in the refrigerant circuit (20).