Heat exchanger unit, air conditioning indoor unit, and refrigeration cycle device

Abstract

The present invention provides improved performance for a heat exchanger having flat tubes in which a plurality of internal flow paths are formed. [Solution] A connecting flow path (75) is formed in a plate structure (62) of a heat exchanger unit (40). The connecting flow path (75) has a first portion (80), a second portion (85), and a third portion (90). All of the in-pipe flow paths (50a) of a first heat transfer tube (51) communicate with the first portion (80). All of the in-pipe flow paths (50a) of a second heat transfer tube (52) communicate with the second portion (85). One end of the third portion (90) is connected to one first long side (81a) of the first portion (80). The other end of the third portion (90) is connected to one second long side (86b) of the second portion (85).

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger unit, an air conditioning indoor unit, and a refrigeration cycle device. [Background technology]

[0002] Patent Document 1 discloses a heat exchanger equipped with a plurality of heat transfer tubes. The heat transfer tubes of this heat exchanger are flat tubes with an oval cross section. Two tube rows are formed in this heat exchanger. In this heat exchanger, the two tube rows are arranged in front and behind each other. Each tube row is composed of a plurality of heat transfer tubes. In each tube row, the plurality of heat transfer tubes are arranged in a row at regular intervals in the vertical direction.

[0003] A header is connected to the ends of the heat transfer tubes in each tube row. The header is composed of a plurality of stacked plate-like members. A connecting flow passage is formed inside the header, connecting the first heat transfer tube that constitutes the front tube row with the second heat transfer tube that constitutes the rear tube row. The connecting flow passage is formed so as to connect the short side of the end face of the first heat transfer tube with the short side of the end face of the second heat transfer tube. The refrigerant flowing through the heat exchanger flows from one of the first heat transfer tube and the second heat transfer tube to the other through the connecting flow passage in the header. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 130834 Summary of the Invention [Problem to be solved by the invention]

[0005] A flat tube used as a heat transfer tube may have multiple internal flow passages. Each internal flow passage is formed from one end of the flat tube to the other. The multiple internal flow passages are aligned in the width direction of the flat tube (the longitudinal direction of the cross section of the flat tube).

[0006] As described above, in the heat exchanger of Patent Document 1, the connecting flow passage in the header connects the short side of the end face of the first heat transfer tube constituting the front tube row with the short side of the end face of the second heat transfer tube constituting the rear tube row. Therefore, when flat tubes with multiple in-pipe flow passages formed therein are used as heat transfer tubes in the heat exchanger of Patent Document 1, the flow rate of refrigerant flowing into each in-pipe flow passage of the flat tube may be greater in in-pipe flow passages closer to the connecting flow passage and may be lower in in-pipe flow passages farther from the connecting flow passage. If the refrigerant flow rates in each in-pipe flow passage of the flat tube become uneven, the heat exchanger will not perform to its full potential.

[0007] An object of the present disclosure is to improve the performance of a heat exchanger including flat tubes in which a plurality of internal flow paths are formed. [Means for solving the problem]

[0008] A first aspect of the present disclosure is a heat exchanger unit (40) including a plurality of fins (53) and a plurality of heat transfer tubes (50), and exchanging heat between a heat medium flowing through the heat transfer tubes (50) and air.

[0009] In a first aspect, each of the plurality of heat transfer tubes (50) is a flat tube having a plurality of in-tube flow paths (50a) formed therein. In each of the plurality of heat transfer tubes (50), the plurality of in-tube flow paths (50a) are arranged in a row in the width direction of the heat transfer tube (50). The plurality of heat transfer tubes (50) includes a plurality of first heat transfer tubes (51) and a plurality of second heat transfer tubes (52). The first heat transfer tubes (51) arranged in a row with a gap between them form a first tube row (56). The second heat transfer tubes (52) arranged in a row with a gap between them form a second tube row (57). The first tube row (56) and the second tube row (57) are arranged in this order from upstream to downstream of the flow of air passing through the heat exchanger unit (40).

[0010] In a first aspect, the heat exchanger unit (40) is joined to ends of the heat transfer tubes (50) and includes a plate structure (62) having a connection flow path (75) formed therein that connects one first heat transfer tube (51) to one second heat transfer tube (52). The connection flow path (75) has a first portion (80) that faces an end face of the first heat transfer tube (51) and communicates with all the in-pipe flow paths (50a) formed in the first heat transfer tube (51), a second portion (85) that faces an end face of the second heat transfer tube (52) and communicates with all the in-pipe flow paths (50a) formed in the second heat transfer tube (52), and a third portion (90) that communicates with both the first portion (80) and the second portion (85).

[0011] In a first aspect, the first portion (80) has a pair of first long sides (81a, 81b) along the width direction of the first heat transfer tube (51), the second portion (85) has a pair of second long sides (86a, 86b) along the width direction of the second heat transfer tube (52), one end of the third portion (90) is connected to only one of the pair of first long sides (81a, 81b) of the first portion (80), and the other end of the third portion (90) is connected to only one of the pair of second long sides (86a, 86b) of the second portion (85).

[0012] In the heat exchanger unit (40) of the first aspect, when the heat medium flows through the connecting flow path (75) from the first heat transfer pipe (51) to the second heat transfer pipe (52), the heat medium flowing through the third portion (90) enters the second portion (85) from the second long sides (86a, 86b) along the width direction of the second heat transfer pipe (52) and is distributed to all of the multiple in-pipe flow paths (50a) aligned in the width direction of the second heat transfer pipe (52). When the heat medium flows through the connecting flow path (75) from the second heat transfer pipe (52) to the first heat transfer pipe (51), the heat medium flowing through the third portion (90) enters the first portion (80) from the first long sides (81a, 81b) along the width direction of the first heat transfer pipe (51) and is distributed to all of the multiple in-pipe flow paths (50a) aligned in the width direction of the first heat transfer pipe (51).

[0013] Therefore, in the first aspect, the heat transfer medium flowing through the connecting flow path (75) is distributed to all the in-pipe flow paths (50a) formed in the heat transfer tube (50), and the difference in flow rate of the heat transfer medium flowing through the in-pipe flow paths (50a) of one heat transfer tube (50) is kept small, thereby improving the performance of the heat exchanger unit (40).

[0014] A second aspect of the present disclosure is the first aspect, wherein the plate structure (62) has a plurality of plate members (65) that are overlapped and joined to each other, and the first portion (80), the second portion (85), and the third portion (90) of the connecting flow path (75) are formed in one of the plate members (65).

[0015] In the second embodiment, the first portion (80), the second portion (85), and the third portion (90) of the connecting flow path (75) are formed in one plate member (65).

[0016] A third aspect of the present disclosure is related to the first aspect, wherein the plate structure (62) has a plurality of plate members (65) that are overlapped and joined to one another, the plurality of plate members (65) including a first plate member (71) and a second plate member (72) that is located on the opposite side of the first plate member (71) from the heat transfer tube (50), the first portion (80) and the second portion (85) of the connecting flow path (75) being formed across both the first plate member (71) and the second plate member (72), and the third portion (90) of the connecting flow path (75) being formed only in the second plate member (72) of the first plate member (71) and the second plate member (72).

[0017] In the third embodiment, the first portion (80) and the second portion (85) of the connecting channel (75) are formed across both the first plate member (71) and the second plate member (72), while the third portion (90) of the connecting channel (75) is formed in the second plate member (72).

[0018] A fourth aspect of the present disclosure is any one of the first to third aspects, wherein the width of the first portion (80) is equal to or greater than the width of the first heat transfer tube (51), the width of the second portion (85) is equal to or greater than the width of the second heat transfer tube (52), and the width of the third portion (90) is equal to or less than the width of the first heat transfer tube (51) and equal to or less than the width of the second heat transfer tube (52).

[0019] In the connecting flow path (75) of the fourth embodiment, the width of the third portion (90) is equal to or smaller than the width of the first portion (80) and equal to or smaller than the width of the second portion (85).

[0020] A fifth aspect of the present disclosure is any one of the first to fourth aspects, wherein the first long side (81a, 81b) of the first part (80) to which one end of the third part (90) is connected is located on the same side as the second long side (86a, 86b) of the second part (85) to which the other end of the third part (90) is connected.

[0021] In the fifth aspect, the first long side 81b of the first portion 80 to which one end of the third portion 90 is connected and the second long side 86b of the second portion 85 to which the other end of the third portion 90 is connected are located on the same side. For example, when one end of the third portion 90 is connected to the first long side 81b on the lower side of the first portion 80, the other end of the third portion 90 is connected to the second long side 86b on the lower side of the second portion 85.

[0022] A sixth aspect of the present disclosure is the fifth aspect, wherein the third portion (90) has a straight portion (94) formed at a position facing the first long sides (81a, 81b) and the second long sides (86a, 86b).

[0023] In the sixth embodiment of the connecting flow path (75), the third portion (90) has straight portions (94). The straight portions (94) are formed at positions facing the first long sides (81a, 81b) of the first portion (80) and the second long sides (86a, 86b) of the second portion (85).

[0024] A seventh aspect of the present disclosure is any one of the first to fourth aspects, wherein the first long side (81a, 81b) of the first part (80) to which one end of the third part (90) is connected is located on the opposite side from the second long side (86a, 86b) of the second part (85) to which the other end of the third part (90) is connected.

[0025] In the seventh aspect, the first long sides (81a, 81b) of the first part (80) to which one end of the third part (90) is connected and the second long sides (86a, 86b) of the second part (85) to which the other end of the third part (90) is connected are located on opposite sides. For example, when one end of the third part (90) is connected to the upper first long side (81a) of the first part (80), the other end of the third part (90) is connected to the lower second long side (86b) of the second part (85).

[0026] An eighth aspect of the present disclosure is the seventh aspect, wherein the widthwise center line (L1) of the connecting flow path (75) is located above a straight line (L2) connecting a midpoint (CP1) of the first long side (81a, 81b) to which one end of the third portion (90) is connected and a midpoint (CP2) of the second long side (86a, 86b) to which the other end of the third portion (90) is connected.

[0027] In the eighth aspect, the center line (L1) of the connection flow path (75) is located above the straight line (L2) connecting the midpoint (CP1) of the first long sides (81a, 81b) and the midpoint (CP2) of the second long sides (86a, 86b).

[0028] A ninth aspect of the present disclosure is any one of the first to fourth aspects, wherein one end of the third portion (90) is connected to a portion of the first long sides (81a, 81b) that includes a midpoint (CP1) of the first long sides (81a, 81b), and the other end of the third portion (90) is connected to a portion of the second long sides (86a, 86b) that includes a midpoint (CP2) of the second long sides (86a, 86b).

[0029] In the ninth aspect, one end of the third portion 90 is connected to a portion of the first long sides 81a, 81b of the first portion 80 that includes the midpoint CP1, and the other end of the third portion 90 is connected to a portion of the second long sides 86a, 86b of the second portion 85 that includes the midpoint CP2.

[0030] A tenth aspect of the present disclosure is an air conditioner indoor unit (30) including the heat exchanger unit (40) of any one of the first to ninth aspects, in which the heat medium is heat exchanged with indoor air in the heat exchanger unit (40).

[0031] In a tenth aspect, any one of the first to ninth heat exchanger units (40) is provided in an air conditioner indoor unit (30).

[0032] An eleventh aspect of the present disclosure is a refrigeration cycle device (10) including a refrigerant circuit (11) having any one of the first to ninth heat exchanger units (40), and performing a refrigeration cycle by circulating a refrigerant in the refrigerant circuit (11).

[0033] In an eleventh aspect, any one of the first to ninth heat exchanger units (40) is provided in a refrigerant circuit (11) of a refrigeration cycle apparatus (10). [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a piping diagram showing a refrigerant circuit of an air conditioner according to a first embodiment. [Figure 2] FIG. 2 is a schematic front view of the indoor unit of the first embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view of the indoor unit of the first embodiment. [Figure 4] FIG. 4 is a schematic front view of the heat exchanger unit provided in the indoor unit of the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view of a main part of a second plate stack and a heat transfer tube in the heat exchanger unit of the first embodiment. [Figure 6]FIG. 6 is a cross-sectional view of a main part of a second plate stack in the heat exchanger unit of the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view of a main part of a second plate stack in a heat exchanger unit according to a first modification of the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a main part of a second plate stack in a heat exchanger unit according to a second modification of the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view of a main part of a second plate stack in a heat exchanger unit according to a third modification of the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a main part of a second plate stack and a heat transfer tube in a heat exchanger unit of the second embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a main part of a second plate stack in a heat exchanger unit of the second embodiment. [Figure 12] FIG. 12 is a cross-sectional view of a main part of a second plate stack in a heat exchanger unit according to a first modification of the second embodiment. [Figure 13] FIG. 13 is a cross-sectional view of a main part of a second plate stack in a heat exchanger unit according to a second modification of the second embodiment. [Figure 14] FIG. 14 is a schematic cross-sectional view of the indoor unit of the third embodiment. [Figure 15] FIG. 15 is a cross-sectional view of a main part of a second plate stack in a heat exchanger unit of the third embodiment. [Figure 16] FIG. 16 is a cross-sectional view of a main part of a second plate stack and a heat transfer tube in a heat exchanger unit according to a first modified example of another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0035] First Embodiment The first embodiment will be described.

[0036] -Overall configuration of air conditioning equipment- This embodiment is an air conditioner (10) including a heat exchanger unit (40). The air conditioner (10) adjusts the temperature of air in an indoor space (200) which is a target space.

[0037] As shown in Fig. 1, the air conditioner (10) is an example of a refrigeration cycle device including a refrigerant circuit (11). The refrigerant circuit (11) is filled with a refrigerant, which is a heat medium. The refrigerant circuit (11) performs a refrigeration cycle by circulating the refrigerant.

[0038] The air conditioner (10) includes an outdoor unit (20), an indoor unit (30), a first connecting pipe (12), and a second connecting pipe (13). The air conditioner (10) is a pair type having one outdoor unit (20) and one indoor unit (30). The first connecting pipe (12) is a gas connecting pipe, and the second connecting pipe (13) is a liquid connecting pipe. In the air conditioner (10), a refrigerant circuit (11) is formed by connecting the outdoor unit (20) and the indoor unit (30) with the first connecting pipe (12) and the second connecting pipe (13).

[0039] The outdoor unit (20) is installed outdoors and includes an outdoor casing (20a), and a compressor (21), an outdoor heat exchanger (22), an outdoor expansion valve (23), a four-way selector valve (24), and an outdoor fan (25) housed in the outdoor casing (20a).

[0040] The compressor (21) is a rotary compressor such as a swing piston type, rotary type, or scroll type. The outdoor heat exchanger (22) is a fin-and-tube air heat exchanger. The outdoor heat exchanger (22) exchanges heat between the refrigerant and outdoor air. The outdoor expansion valve (23) is an electronic expansion valve with a variable opening. The four-way selector valve (24) switches between a first state (shown by the solid line in FIG. 1 ) and a second state (shown by the dashed line in FIG. 1 ). In the first state, the four-way selector valve (24) connects the discharge port of the compressor (21) to the gas end of the outdoor heat exchanger (22) and connects the suction port of the compressor (21) to the first connecting pipe (12). The four-way selector valve (24) in the second state communicates the discharge port of the compressor (21) with the first communication pipe (12) and also communicates the suction port of the compressor (21) with the gas end of the outdoor heat exchanger (22). The outdoor fan (25) is a propeller fan.

[0041] The indoor unit (30) includes a casing (31), and a heat exchanger unit (40) and an indoor fan (32) housed in the casing (31).

[0042] -Air conditioning unit operation- The air conditioner (10) selectively performs cooling operation and heating operation.

[0043] In the cooling operation, the four-way selector valve (24) is set to the position indicated by the solid line in Fig. 1. When the compressor (21) is activated, refrigerant circulates in the refrigerant circuit (11) to perform a refrigeration cycle. In the refrigerant circuit (11), the outdoor heat exchanger (22) functions as a condenser, and the indoor heat exchanger (41) functions as an evaporator. The indoor unit (30) blows the air cooled in the indoor heat exchanger (41) into the indoor space (200).

[0044] In the heating operation, the four-way selector valve (24) is set to the state shown by the dashed line in Fig. 1. When the compressor (21) is activated, refrigerant circulates in the refrigerant circuit (11) to perform a refrigeration cycle. In the refrigerant circuit (11), the indoor heat exchanger (41) functions as a condenser, and the outdoor heat exchanger (22) functions as an evaporator. The indoor unit (30) blows out the air heated in the indoor heat exchanger (41) into the indoor space (200).

[0045] -Indoor unit- The indoor unit (30), which is an indoor air conditioner, will be described in detail with reference to Figures 2 and 3. The indoor unit (30) of this embodiment is a wall-mounted type that is installed on a wall of the indoor space (200). Note that the terms "upper," "lower," "right," "left," "front," and "rear" described below correspond to the directions of the arrows shown in Figures 2 and 3 and indicate directions when the indoor unit (30) is viewed from the front.

[0046] <Casing> The casing (31) is formed in the shape of a laterally elongated box.

[0047] An air inlet (33) is formed in the upper part of the casing (31). The air inlet (33) extends in the longitudinal direction (left-right direction) of the casing (31). An air outlet (34) is formed in the lower part of the casing (31). The air outlet (34) extends in the longitudinal direction of the casing (31).

[0048] <Heat exchanger unit> The heat exchanger unit (40) includes an indoor heat exchanger (41) and an indoor expansion valve (42). The indoor heat exchanger (41) includes a heat exchanger body (45) and two plate stacks (61, 62).

[0049] Indoor fan The indoor fan (32) is a cross-flow fan and is disposed below the heat exchanger unit (40). A fan rotor of the indoor fan (32) extends in the longitudinal direction of the casing (31).

[0050] <flap> The indoor unit (30) has a flap (36) that adjusts the direction of air blown out from the air outlet (34). The flap (36) adjusts the air direction in the vertical direction. The indoor unit (30) may have multiple flaps (36). The flap (36) may adjust the air direction in the horizontal direction.

[0051] -Heat exchanger unit- As described above, the heat exchanger unit (40) includes the indoor heat exchanger (41) and the indoor expansion valve (42).

[0052] <Indoor heat exchanger> As described above, the indoor heat exchanger (41) includes one heat exchanger body (45) and two plate stacks (61, 62). The indoor heat exchanger (41) is a fin-and-tube air heat exchanger. The indoor heat exchanger (41) exchanges heat between the refrigerant and the indoor air. Each plate stack (61, 62) has a plate structure. The number of plate stacks (61, 62) included in the indoor heat exchanger (41) is merely an example.

[0053] <Heat exchanger body> As shown in Fig. 3, the heat exchanger body (45) includes a first heat exchange section (46), a second heat exchange section (47), and a third heat exchange section (48). The first heat exchange section (46) and the second heat exchange section (47) form a front heat exchange section (45A). The third heat exchange section (48) forms a rear heat exchange section (45B). The number of heat exchange sections included in the heat exchanger body (45) is merely an example. The number of heat exchange sections included in the heat exchanger body (45) may be one or more.

[0054] The front heat exchange section (45A) is located near the front of the casing (31). The rear heat exchange section (45B) is located near the rear of the casing (31). The heat exchanger body (45) is provided so as to surround the front, upper, and rear sides of the indoor fan (32).

[0055] <Indoor expansion valve> The indoor expansion valve (42) is an electronic expansion valve with a variable opening. As shown in Fig. 1, one end of the indoor expansion valve (42) is connected to the front heat exchange section (45A) via a pipe. The other end of the indoor expansion valve (42) is connected to the rear heat exchange section (45B) via a pipe.

[0056] <First heat exchange section, second heat exchange section, third heat exchange section> 3, each of the first heat exchange section (46), the second heat exchange section (47), and the third heat exchange section (48) includes a plurality of fins (53) and a plurality of heat transfer tubes (50). The fins (53) and the heat transfer tubes (50) are made of an aluminum alloy. However, the fins (53) and the heat transfer tubes (50) may be made of a metal other than an aluminum alloy.

[0057] The fins (53) are generally rectangular thin plate-like members. In each heat exchanger (46, 47, 48), the fins (53) are aligned in a row in the left-right direction in FIG. 4, facing each other and spaced apart at regular intervals.

[0058] As shown in Fig. 3, the heat transfer tube (50) is a flat tube having an oval cross section. The heat transfer tube (50) is a straight tube. The outer surface of the heat transfer tube (50) includes a pair of flat surfaces. In each heat exchange section (46, 47, 48), the plurality of heat transfer tubes (50) are arranged in the long side direction of the fins (53) at regular intervals with their flat surfaces facing each other.

[0059] Each of the heat exchange sections (46, 47, 48) is formed with a first tube row (56) and a second tube row (57). Each of the first tube row (56) and the second tube row (57) is formed with a plurality of heat transfer tubes (50). In each of the first tube row (56) and the second tube row (57), the plurality of heat transfer tubes (50) are arranged in a row at regular intervals along the long sides of the fins (53).

[0060] The heat transfer tubes (50) constituting the first tube row (56) are first heat transfer tubes (51). In the first tube row (56), the plurality of first heat transfer tubes (51) are arranged in a row at a constant pitch. The heat transfer tubes (50) constituting the second tube row (57) are second heat transfer tubes (52). In the second tube row (57), the plurality of second heat transfer tubes (52) are arranged in a row at a constant pitch. The pitch of the plurality of first heat transfer tubes (51) in the first tube row (56) and the pitch of the plurality of second heat transfer tubes (52) in the second tube row (57) are equal to each other.

[0061] In each heat exchange section (46, 47, 48), the first tube row (56) is aligned along the long side of the fins (53) on the upwind side, and the second tube row (57) is aligned along the long side of the fins (53) on the downwind side. In each heat exchange section (46, 47, 48), the first heat transfer tubes (51) of the first tube row (56) and the second heat transfer tubes (52) of the second tube row (57) are aligned along the short side of the fins (53). Therefore, each first heat transfer tube (51) and the second heat transfer tube (52) closest to the first heat transfer tube (51) are aligned in the long side of the fins (53).

[0062] The first heat exchange section (46) is disposed with the long sides of the fins (53) on the windward side facing forward and diagonally upward. The second heat exchange section (47) is disposed with the long sides of the fins (53) on the windward side facing forward and diagonally downward. The second heat exchange section (47) is disposed below the first heat exchange section (46). The third heat exchange section (48) is disposed with the long sides of the fins (53) on the windward side facing backward and diagonally upward.

[0063] <Heat transfer tube> As shown in FIGS. 5 and 6, the heat transfer tube (50) is a flattened tube having an oval cross section. The heat transfer tube (50) is a straight tube. The overall length of the heat transfer tube (50) is the distance from one end face to the other end face of the heat transfer tube (50). The width Wt of the heat transfer tube (50) is the length of the cross section of the heat transfer tube (50) in the longitudinal direction. The thickness THt of the heat transfer tube (50) is the length of the cross section of the heat transfer tube (50) in the lateral direction. The plurality of heat transfer tubes (50) provided in each heat exchange section (46, 47, 48) have substantially the same width Wt and substantially the same thickness THt.

[0064] A plurality of in-pipe flow paths (50a) are formed in the heat transfer tube (50). In the example shown in FIGS. 5 and 6, five in-pipe flow paths (50a) are formed in the heat transfer tube (50). Each in-pipe flow path (50a) is a straight flow path formed from one end to the other end of the heat transfer tube (50). Each in-pipe flow path (50a) opens to one end face and the other end face of the heat transfer tube (50). In the heat transfer tube (50), the plurality of in-pipe flow paths (50a) are arranged parallel to one another. In the heat transfer tube (50), the plurality of in-pipe flow paths (50a) are aligned in a line in the width direction of the heat transfer tube (50).

[0065] <First plate stack, second plate stack> Each of the first plate stack (61) and the second plate stack (62) is a thick plate-like member formed by stacking a plurality of plate members. A refrigerant flow path is formed inside each of the plate stacks (61, 62) to connect two or more heat transfer tubes (50).

[0066] The plate members (65) constituting each of the plate stacks (61, 62) are joined to each other by brazing. The plate members (65) constituting each of the plate stacks (61, 62) are each made of an aluminum alloy. However, the plate members (65) may be made of a metal other than an aluminum alloy.

[0067] The first plate stack (61) is disposed on the right side of the heat exchanger body (45) in Fig. 4. The first plate stack (61) is joined to one end of the heat transfer tube (50) of each heat exchange section (46, 47, 48).

[0068] The second plate stack (62) is disposed on the left side of the heat exchanger body (45) in Fig. 4. The second plate stack (62) is joined to the other end of the heat transfer tube (50) of each heat exchange section (46, 47, 48).

[0069] -Second plate stack- The second plate stack (62) will be described with reference to Fig. 5. Fig. 5 shows a cross section of a portion of the second plate stack (62) that is connected to the heat transfer tubes (50) of the first heat exchange section (46). In Fig. 5, cross sections 5A-5A and 5B-5B are cross sections taken along the cutting line indicated by cross section 5C-5C. Cross section 5C-5C is also a cross section taken along the cutting line indicated by cross sections 5A-5A and 5B-5B.

[0070] The second plate stack 62 of this embodiment includes three plate members 65. However, the second plate stack 62 may include four or more plate members 65.

[0071] Specifically, the second plate stack (62) includes a base plate (70), a first plate (71), and a second plate (72). Each of the base plate (70), the first plate (71), and the second plate (72) is a plate member (65). Each of the base plate (70), the first plate (71), and the second plate (72) is formed in a flat plate shape.

[0072] In the second plate stack (62), a base plate (70), a first plate (71), and a second plate (72) are arranged in order from the side closest to the heat transfer tube (50). The second plate (72) is arranged on the opposite side of the first plate (71) from the side on which the heat transfer tube (50) is arranged. The base plate (70) is joined to the first plate (71), and the first plate (71) is joined to the second plate (72) by brazing.

[0073] An end portion of the first heat transfer tube (51) constituting the first tube row (56) and an end portion of the second heat transfer tube (52) constituting the second tube row (57) are inserted into the base plate (70). The first heat transfer tube (51) and the second heat transfer tube (52) are joined to the base plate (70) by brazing.

[0074] A connection flow path (75) is formed in the first plate (71). The connection flow path (75) is formed by a hole penetrating the first plate (71). The connection flow path (75) is a refrigerant flow path that connects one first heat transfer pipe (51) and one second heat transfer pipe (52).

[0075] 5 connects one first heat transfer pipe (51) to one second heat transfer pipe (52) located adjacent to the first heat transfer pipe (51) immediately above the first heat transfer pipe (51). The connection flow path (75) communicates with all the in-pipe flow paths (50a) formed in the first heat transfer pipe (51) and with all the in-pipe flow paths (50a) formed in the second heat transfer pipe (52).

[0076] The second plate (72) covers the connecting flow path (75) of the first plate (71) and seals the connecting flow path (75).

[0077] -Connecting channel of second plate stack- The connecting flow passages 75 formed in the second plate stack 62 will be described with reference to Fig. 6. Fig. 6 is an enlarged view of the "5C-5C cross section" shown in Fig. 5.

[0078] The connecting flow path (75) is divided into a first portion (80), a second portion (85), and a third portion (90).

[0079] <Part 1> The first portion (80) is a portion that overlaps with the end surface of the first heat transfer tube (51) when viewed from the front side of the end surface of the first heat transfer tube (51). The first portion (80) overlaps the entire end surface of the first heat transfer tube (51). The shape of the first portion (80) when viewed from the stacking direction of the plate members (65) of the second plate stack (62) (in other words, the shape that appears in FIG. 6) substantially matches the shape of the end surface of the first heat transfer tube (51). The width Wp1 of the first portion (80) is substantially equal to the width Wt of the first heat transfer tube (51).

[0080] The first portion (80) covers the end face of the first heat transfer pipe (51). The end face of the first heat transfer pipe (51) faces the first portion (80). All (five in the example shown in FIG. 6 ) in-pipe flow paths (50a) formed in the first heat transfer pipe (51) communicate with the first portion (80).

[0081] The first portion (80) has a pair of first long sides (81a, 81b) and a pair of first semicircular portions (82a, 82b). Each of the first long sides (81a, 81b) is a straight portion extending along the width direction of the first heat transfer tube (51). The first long sides (81a, 81b) are substantially parallel to each other. Each of the first semicircular portions (82a, 82b) is a portion curved in a semicircular arc shape. One of the first semicircular portions (82a) is connected to one end of each of the first long sides (81a, 81b). The other of the first semicircular portions (82b) is connected to the other end of each of the first long sides (81a, 81b).

[0082] <Second part> The second portion (85) is a portion that overlaps with the end surface of the second heat transfer tube (52) when viewed from the front side of the end surface of the second heat transfer tube (52). The second portion (85) overlaps the entire end surface of the second heat transfer tube (52). The shape of the second portion (85) when viewed from the stacking direction of the plate members (65) of the second plate stack (62) (in other words, the shape that appears in FIG. 6) substantially matches the shape of the end surface of the second heat transfer tube (52). The width Wp2 of the second portion (85) is substantially equal to the width Wt of the second heat transfer tube (52).

[0083] The second portion (85) covers the end face of the second heat transfer pipe (52). The end face of the second heat transfer pipe (52) faces the second portion (85). All (five in the example shown in FIG. 6 ) in-pipe flow paths (50a) formed in the second heat transfer pipe (52) communicate with the second portion (85).

[0084] The second portion (85) has a pair of second long sides (86a, 86b) and a pair of second semicircular portions (87a, 87b). Each of the second long sides (86a, 86b) is a straight portion extending along the width direction of the second heat transfer tube (52). The second long sides (86a, 86b) are substantially parallel to each other. Each of the second semicircular portions (87a, 87b) is a portion curved in a semicircular arc shape. One of the second semicircular portions (87a) is connected to one end of each of the second long sides (86a, 86b). The other of the second semicircular portions (87b) is connected to the other end of each of the second long sides (86a, 86b).

[0085] <3rd part> The third portion (90) is a portion that connects the first portion (80) and the second portion (85). The third portion (90) communicates with both the first portion (80) and the second portion (85).

[0086] The third portion (90) extends diagonally in a straight line from the first portion (80) toward the second portion (85). One side portion (90a) of the third portion (90) is a straight portion connecting one of the first semicircular portions (82a) of the first portion (80) and one of the second semicircular portions (87a) of the second portion (85). The other side portion (90b) of the third portion (90) is a straight portion connecting the other of the first semicircular portions (82b) of the first portion (80) and the other of the second semicircular portions (87b) of the second portion (85).

[0087] One end of the third portion (90) is connected to the upper first long side (81a) of the first portion (80) and the other first semicircular portion (82b). Therefore, one end of the third portion (90) is connected to only one of the pair of first long sides (81a, 81b) of the first portion (80). Furthermore, one end of the third portion (90) is connected to the entire first long side (81a). Therefore, one end of the third portion (90) is connected to a portion of the first long side (81a) that includes the midpoint (CP1) of the first long side (81a).

[0088] The other end of the third portion 90 is connected to the lower second long side 86b of the second portion 85 and one of the second semicircular portions 87a. Therefore, the other end of the third portion 90 is connected to only one of the pair of second long sides 86a, 86b of the second portion 85. The other end of the third portion 90 is connected to the entire second long side 86b. Therefore, the other end of the third portion 90 is connected to a portion of the second long side 86b that includes the midpoint CP2 of the second long side 86b.

[0089] One end of the third portion (90) is connected to the upper first long side (81 a) of the first portion (80), and the other end of the third portion (90) is connected to the lower second long side (86 b) of the second portion (85). Therefore, the first long side (81 a) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side from the second long side (86 b) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86 b) of the second portion (85) to which the other end of the third portion (90) is connected is the second long side of the pair of second long sides (86 a, 86 b) of the second portion (85) that is closer to the first long side (81 a) of the first portion (80) to which one end of the third portion (90) is connected.

[0090] - Refrigerant flow in the connecting channel - In the connecting flow passage (75) of the second plate stack (62), the refrigerant flows from one of the first heat transfer pipe (51) and the second heat transfer pipe (52) to the other. The flow direction of the refrigerant in the indoor heat exchanger (41) is reversed during cooling operation and heating operation. Therefore, for example, if the refrigerant flows through the connecting flow passage (75) from the second heat transfer pipe (52) to the first heat transfer pipe (51) during cooling operation, the refrigerant flows through the connecting flow passage (75) from the first heat transfer pipe (51) to the second heat transfer pipe (52) during heating operation.

[0091] <First heat transfer tube → Second heat transfer tube> The flow of the refrigerant in the connection flow path (75) when the refrigerant flows from the first heat transfer pipe (51) to the second heat transfer pipe (52) will be described.

[0092] The refrigerant flowing through the in-pipe flow paths (50a) of the first heat transfer pipe (51) flows into the first portion (80) of the connecting flow path (75) and joins there. The refrigerant joined in the first portion (80) flows through the third portion (90) and into the second portion (85). The refrigerant flowing into the second portion (85) splits into the in-pipe flow paths (50a) of the second heat transfer pipe (52).

[0093] As described above, the other end of the third portion (90) is connected to the entire second long side (86b) of the second portion (85). All of the in-pipe flow paths (50a) aligned in the width direction of the second heat transfer pipe (52) open to the end face of the second heat transfer pipe (52) facing the second portion (85). Therefore, the refrigerant flowing from the third portion (90) to the second portion (85) is distributed approximately evenly to all of the in-pipe flow paths (50a) formed in the second heat transfer pipe (52).

[0094] <Second heat transfer tube → First heat transfer tube> The flow of the refrigerant in the connection flow path (75) when the refrigerant flows from the second heat transfer pipe (52) to the first heat transfer pipe (51) will be described.

[0095] The refrigerant flowing through the in-pipe flow paths (50a) of the second heat transfer pipe (52) flows into the second portion (85) of the connecting flow path (75) and joins there. The refrigerant joined in the second portion (85) flows through the third portion (90) and into the first portion (80). The refrigerant flowing into the first portion (80) splits into the in-pipe flow paths (50a) of the first heat transfer pipe (51).

[0096] As described above, the other end of the third portion (90) is connected to the entire first long side (81a) of the first portion (80). All of the in-pipe flow paths (50a) aligned in the width direction of the first heat transfer pipe (51) open to the end face of the first heat transfer pipe (51) facing the first portion (80). Therefore, the refrigerant flowing from the third portion (90) to the first portion (80) is distributed approximately evenly to all of the in-pipe flow paths (50a) formed in the first heat transfer pipe (51).

[0097] -Features of the first embodiment- In the heat exchanger unit (40) of this embodiment, when the refrigerant flows through the connecting flow path (75) from the first heat transfer pipe (51) to the second heat transfer pipe (52), the heat medium flowing through the third portion (90) flows into the second portion (85) from the second long sides (86a, 86b) along the width direction of the second heat transfer pipe (52) and is distributed approximately evenly to all of the multiple in-pipe flow paths (50a) aligned in the width direction of the second heat transfer pipe (52). When the refrigerant flows through the connecting flow path (75) from the second heat transfer pipe (52) to the first heat transfer pipe (51), the heat medium flowing through the third portion (90) flows into the first portion (80) from the first long sides (81a, 81b) along the width direction of the first heat transfer pipe (51) and is distributed approximately evenly to all of the multiple in-pipe flow paths (50a) aligned in the width direction of the first heat transfer pipe (51).

[0098] In the heat exchanger unit (40) of this embodiment, the refrigerant flowing through the connecting flow path (75) is distributed approximately evenly to all the in-pipe flow paths (50a) formed in the heat transfer tubes (50), and the difference in the flow rate of the refrigerant flowing through the in-pipe flow paths (50a) of one heat transfer tube (50) is kept small. Therefore, according to this embodiment, the performance of the heat exchanger unit (40) can be improved.

[0099] -Modification 1 of Embodiment 1- The connecting flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path having a shape shown in Fig. 7. In the connecting flow path (75) shown in Fig. 7, the third portion (90) is divided into a first end portion (91), a second end portion (92), and an intermediate portion (93).

[0100] The first end portion (91) is a portion that includes one end of the connecting flow path (75). The first end portion (91) is connected to the entire upper first long side (81a) of the first portion (80). Therefore, the first end portion (91) is connected to a portion of the first long side (81a) that includes the midpoint (CP1) of the first long side (81a). The width of the first end portion (91) is substantially equal to the width Wp1 of the first portion (80).

[0101] The second end portion (92) is a portion that includes the other end of the connecting flow path (75). The second end portion (92) is connected to the entire lower second long side (86b) of the second portion (85). Therefore, the second end portion (92) is connected to a portion of the second long side (86b) that includes the midpoint (CP2) of the second long side (86b). The width of the second end portion (92) is substantially equal to the width Wp2 of the second portion (85).

[0102] The intermediate portion (93) connects the first end (91) and the second end (92). The intermediate portion (93) extends diagonally and linearly from the first end (91) to the second end (92). The width Wp3 of the intermediate portion (93) is slightly narrower than the width Wp1 of the first portion (80) and the width Wp2 of the second portion (85).

[0103] -Modification 2 of Embodiment 1- The connecting flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path having a shape shown in Fig. 8. In the connecting flow path (75) shown in Fig. 8, the third portion (90) is divided into a first end portion (91), a second end portion (92), and an intermediate portion (93).

[0104] The first end portion (91) is a portion that includes one end of the connection flow path (75). The first end portion (91) is connected to the entire upper first long side (81a) of the first portion (80). Therefore, the first end portion (91) is connected to a portion of the first long side (81a) that includes the midpoint (CP1) of the first long side (81a). The width of the first end portion (91) gradually narrows upward from the upper first long side (81a) of the first portion (80).

[0105] The second end portion (92) is a portion that includes the other end of the connecting flow path (75). The second end portion (92) is connected to the entire lower second long side (86b) of the second portion (85). Therefore, the second end portion (92) is connected to a portion of the second long side (86b) that includes the midpoint (CP2) of the second long side (86b). The width of the second end portion (92) gradually narrows downward from the lower second long side (86b) of the second portion (85).

[0106] The intermediate portion (93) is a portion that connects the first end portion (91) and the second end portion (92). The intermediate portion (93) extends linearly in a diagonal direction from the first end portion (91) toward the second end portion (92). The width Wp3 of the intermediate portion (93) is significantly narrower than both the width Wp1 of the first portion (80) and the width Wp2 of the second portion (85).

[0107] -Modification 3 of Embodiment 1- The connecting flow passage (75) formed in the second plate assembly (62) of this embodiment may be a flow passage having a shape shown in FIG.

[0108] 9, the lower side portion (90b) is curved upward. One end of the side portion (90b) is connected to the vicinity of the other end of the upper first long side (81a) of the first portion (80). The other end of the side portion (90b) is connected to the vicinity of the other end of the lower second long side (86b) of the second portion (85).

[0109] The center line (L1) in the width direction of the connecting flow path (75) is located above the straight line (L2) connecting the midpoint (CP1) of the first long side (81a) of the first portion (80) and the midpoint (CP2) of the second long side (86b) of the second portion (85).

[0110] Here, during operation of the air conditioner (10), a gas-liquid two-phase refrigerant may flow through the connecting flow path (75). When the gas-liquid two-phase refrigerant flows through the connecting flow path (75), gas refrigerant may be unevenly distributed in a region along the upper side portion (90a) of the connecting flow path (75), and liquid refrigerant may be unevenly distributed in a region along the lower side portion (90b) of the connecting flow path (75). As a result, the ratio of liquid refrigerant to gas refrigerant in the refrigerant flowing into each in-pipe flow path (50a) of the heat transfer tube (50) may become uneven.

[0111] On the other hand, in the connection flow path (75) of this modified example, the lower side portion (90b) is formed in a curved shape that is bent upward. Furthermore, in the connection flow path (75) of this modified example, the center line (L1) in the width direction is located above the line (L2) that connects the midpoint (CP1) of the first long side (81a) and the midpoint (CP2) of the second long side (86b). Therefore, when refrigerant in a gas-liquid two-phase state flows through the connection flow path (75) of this modified example, the mixture ratio of gas refrigerant and liquid refrigerant throughout the connection flow path (75) is more uniform than when refrigerant in a gas-liquid two-phase state flows through the connection flow path (75) shown in FIG.

[0112] Therefore, according to this modification, the ratio of liquid refrigerant to gas refrigerant in the refrigerant flowing from the connecting flow path (75) into each of the in-pipe flow paths (50a) of the heat transfer tube (50) can be made uniform.

[0113] -Fourth Modification of First Embodiment- The connection flow path (75) formed in the second plate stack (62) of the present embodiment may connect one first heat transfer tube (51) to one second heat transfer tube (52) located adjacent to the first heat transfer tube (51) immediately below the first heat transfer tube (51).

[0114] In the connection flow path (75) of this modified example, one end of the third portion (90) is connected to the lower first long side (81b) of the first portion (80). One end of the third portion (90) is connected to the entire first long side (81b). Therefore, one end of the third portion (90) is connected to a portion of the first long side (81b) that includes the midpoint of the first long side (81b).

[0115] In the connection flow path (75) of this modified example, the other end of the third portion (90) is connected to the upper second long side (86a) of the second portion (85). The other end of the third portion (90) is connected to the entire second long side (86a). Therefore, the other end of the third portion (90) is connected to a portion of the second long side (86a) that includes the midpoint of the second long side (86a).

[0116] In the connection flow path (75) of this modified example, one end of the third portion (90) is connected to the lower first long side (81b) of the first portion (80), and the other end of the third portion (90) is connected to the upper second long side (86a) of the second portion (85). Therefore, the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side from the second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected is the second long side of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected.

[0117] This modification can also be applied to the connection flow path (75) of the first to third modifications of this embodiment.

[0118] -Modification 5 of Embodiment 1- In the connection flow path (75) of this embodiment, one end of the third portion (90) may be connected to a part of the upper first long side (81 a) of the first portion (80). In this modification, it is preferable that one end of the third portion (90) be connected to a portion of the first long side (81 a) that includes the midpoint (CP1) of the first long side (81 a). It is also preferable that one end of the third portion (90) be connected to an area of at least half of the first long side (81 a).

[0119] This modification can also be applied to the connection flow path (75) in the first to fourth modifications of this embodiment.

[0120] -Modification 6 of Embodiment 1- In the connecting flow path (75) of this embodiment, the other end of the third portion (90) may be connected to a portion of the lower second long side (86b) of the second portion (85). In this modification, it is preferable that one end of the third portion (90) be connected to a portion of the second long side (86b) that includes the midpoint (CP2) of the second long side (86b). It is also preferable that one end of the third portion (90) be connected to an area of at least half of the second long side (86b).

[0121] This modification can also be applied to the connection flow path (75) of the first to fifth modifications of this embodiment.

[0122] Second Embodiment A second embodiment will be described.

[0123] In the air conditioner (10) of this embodiment, the connection flow path (75) formed in the second plate stack (62) of the heat exchanger unit (40) is different from the connection flow path (75) of embodiment 1. Here, the connection flow path (75) formed in the second plate stack (62) of this embodiment will be described, focusing on the differences from the connection flow path (75) of embodiment 1.

[0124] -Connecting channel of second plate stack- Fig. 10 shows a cross section of a portion of the second plate stack 62 that is connected to the heat transfer tubes 50 of the first heat exchange section 46. In Fig. 10, the 10A-10A cross section is taken along the line indicated by the 10B-10B cross section. The 10B-10B cross section is taken along the line indicated by the 10A-10A cross section.

[0125] 10, the connection flow path (75) of this embodiment connects one first heat transfer pipe (51) to one second heat transfer pipe (52) located adjacent to the first heat transfer pipe (51). Thus, the connection flow path (75) of this embodiment connects one first heat transfer pipe (51) to one second heat transfer pipe (52) that is closest to the first heat transfer pipe (51). The connection flow path (75) of this embodiment is formed in the first plate (71), similar to the connection flow path (75) of the first embodiment.

[0126] As shown in FIG. 11, the connecting flow path (75) is divided into a first portion (80), a second portion (85), and a third portion (90).

[0127] <Part 1> The first portion (80) of this embodiment has the same shape as the first portion (80) of the first embodiment. Like the first portion (80) of the first embodiment, the first portion (80) of this embodiment overlaps the entire end surface of the first heat transfer tube (51) and covers the end surface of the first heat transfer tube (51). The end surface of the first heat transfer tube (51) faces the first portion (80). All of the in-pipe flow paths (50a) formed in the first heat transfer tube (51) communicate with the first portion (80). The first portion (80) has a pair of first long sides (81a, 81b) and a pair of first semicircular portions (82a, 82b).

[0128] <Second part> The second portion (85) of this embodiment has the same shape as the second portion (85) of the first embodiment. However, the second heat transfer tube (52) corresponding to the second portion (85) of this embodiment is provided at a different position from the second heat transfer tube (52) corresponding to the second portion (85) of the first embodiment. Like the second portion (85) of the first embodiment, the second portion (85) of this embodiment overlaps the entire end surface of the second heat transfer tube (52) and covers the end surface of the second heat transfer tube (52). The end surface of the second heat transfer tube (52) faces the second portion (85). All the in-pipe flow paths (50a) formed in the second heat transfer tube (52) communicate with the second portion (85). The second portion (85) has a pair of second long sides (86a, 86b) and a pair of second semicircular portions (87a, 87b).

[0129] <3rd part> The third portion (90) is a portion that connects the first portion (80) and the second portion (85). The third portion (90) communicates with both the first portion (80) and the second portion (85).

[0130] The third portion (90) is a V-shaped flow path located below the first portion (80) and the second portion (85). A flat linear portion (94) is formed at the bottom of the V-shaped third portion (90). The linear portion (94) faces the lower first long side (81b) of the first portion (80) and the lower second long side (86b) of the second portion (85).

[0131] One end of the third portion 90 is connected to the lower first long side 81b of the first portion 80. Therefore, one end of the third portion 90 is connected to only one of the pair of first long sides 81a, 81b of the first portion 80. Furthermore, one end of the third portion 90 is connected to the entire first long side 81b. Therefore, one end of the third portion 90 is connected to a portion of the first long side 81b that includes the midpoint CP1 of the first long side 81b.

[0132] The other end of the third portion 90 is connected to the lower second long side 86b of the second portion 85. Therefore, the other end of the third portion 90 is connected to only one of the pair of second long sides 86a, 86b of the second portion 85. In addition, the other end of the third portion 90 is connected to the entire second long side 86b. Therefore, the other end of the third portion 90 is connected to a portion of the second long side 86b that includes the midpoint CP2 of the second long side 86b.

[0133] One end of the third portion 90 is connected to the first long side 81b of the lower side of the first portion 80, and the other end of the third portion 90 is connected to the second long side 86b of the lower side of the second portion 85. Therefore, the first long side 81b of the first portion 80 to which one end of the third portion 90 is connected is located on the same side as the second long side 86b of the second portion 85 to which the other end of the third portion 90 is connected. The second long side 86b of the second portion 85 to which the other end of the third portion 90 is connected is the second long side of the pair of second long sides 86a, 86b of the second portion 85 that is closer to the first long side 81b of the first portion 80 to which one end of the third portion 90 is connected.

[0134] - Refrigerant flow in the connecting channel - In the connecting flow path (75) of the second plate stack (62), as in the first embodiment, the refrigerant flows from one of the first heat transfer pipe (51) and the second heat transfer pipe (52) to the other.

[0135] <First heat transfer tube → Second heat transfer tube> The flow of the refrigerant in the connection flow path (75) when the refrigerant flows from the first heat transfer pipe (51) to the second heat transfer pipe (52) will be described.

[0136] The refrigerant flowing through the in-pipe flow paths (50a) of the first heat transfer pipe (51) flows into the first portion (80) of the connecting flow path (75) and joins there. The refrigerant joined in the first portion (80) flows through the third portion (90) and into the second portion (85). The refrigerant flowing into the second portion (85) splits into the in-pipe flow paths (50a) of the second heat transfer pipe (52).

[0137] As described above, the other end of the third portion (90) is connected to the entire second long side (86b) of the second portion (85). All of the in-pipe flow paths (50a) aligned in the width direction of the second heat transfer pipe (52) open to the end face of the second heat transfer pipe (52) facing the second portion (85). Therefore, the refrigerant flowing from the third portion (90) to the second portion (85) is distributed approximately evenly to all of the in-pipe flow paths (50a) formed in the second heat transfer pipe (52).

[0138] <Second heat transfer tube → First heat transfer tube> The flow of the refrigerant in the connection flow path (75) when the refrigerant flows from the second heat transfer pipe (52) to the first heat transfer pipe (51) will be described.

[0139] The refrigerant flowing through the in-pipe flow paths (50a) of the second heat transfer pipe (52) flows into the second portion (85) of the connecting flow path (75) and joins there. The refrigerant joined in the second portion (85) flows through the third portion (90) and into the first portion (80). The refrigerant flowing into the first portion (80) splits into the in-pipe flow paths (50a) of the first heat transfer pipe (51).

[0140] As described above, the other end of the third portion (90) is connected to the entire first long side (81b) of the first portion (80). All of the in-pipe flow paths (50a) aligned in the width direction of the first heat transfer pipe (51) open to the end face of the first heat transfer pipe (51) facing the first portion (80). Therefore, the refrigerant flowing from the third portion (90) to the first portion (80) is distributed approximately evenly to all of the in-pipe flow paths (50a) formed in the first heat transfer pipe (51).

[0141] -Features of the second embodiment- In the heat exchanger unit (40) of this embodiment, similarly to the heat exchanger unit (40) of the first embodiment, the refrigerant flowing through the connecting flow path (75) is distributed approximately evenly to all the in-pipe flow paths (50a) formed in the heat transfer tubes (50), and the difference in the flow rate of the refrigerant flowing through the in-pipe flow paths (50a) of one heat transfer tube (50) is kept small. Therefore, according to this embodiment, the performance of the heat exchanger unit (40) can be improved.

[0142] -Modification 1 of Embodiment 2- The connecting flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path having a shape shown in Fig. 12. The connecting flow path (75) of this modification differs from the connecting flow path (75) of Fig. 11 in the shape of the third portion (90).

[0143] The third portion (90) of this modified example is a U-shaped flow path located below the first portion (80) and the second portion (85). A flat linear portion (94) is formed at the bottom of the U-shaped third portion (90). This linear portion (94), like the linear portion (94) of the connecting flow path (75) shown in FIG. 11 , faces the lower first long side (81 b) of the first portion (80) and faces the lower second long side (86 b) of the second portion (85).

[0144] -Modification 2 of Embodiment 2- The connecting flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path having a shape shown in Fig. 13. The connecting flow path (75) of this modification differs from the connecting flow path (75) of Fig. 11 in the shape of the third portion (90).

[0145] The third portion (90) of this modified example is a U-shaped flow path located below the first portion (80) and the second portion (85). The sidewall of the third portion (90) of this modified example is curved throughout. Therefore, the third portion (90) of this modified example does not have a flat, straight portion (94).

[0146] -Modification 2 of Embodiment 2- In the connecting flow passage (75) formed in the second plate assembly (62) of this embodiment, the third portion (90) may be located above the first portion (80) and the second portion (85).

[0147] In the connection flow path (75) of this modified example, one end of the third portion (90) is connected to the upper first long side (81 a) of the first portion (80). One end of the third portion (90) is connected to the entire first long side (81 a). Therefore, one end of the third portion (90) is connected to a portion of the first long side (81 a) that includes the midpoint of the first long side (81 a).

[0148] The other end of the third portion 90 is connected to the upper second long side 86a of the second portion 85. The other end of the third portion 90 is connected to the entire second long side 86a. Therefore, the other end of the third portion 90 is connected to a portion of the second long side 86a that includes the midpoint of the second long side 86a.

[0149] One end of the third portion (90) is connected to the upper first long side (81 a) of the first portion (80), and the other end of the third portion (90) is connected to the upper second long side (86 a) of the second portion (85). Therefore, the first long side (81 a) of the first portion (80) to which one end of the third portion (90) is connected is located on the same side as the second long side (86 a) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86 a) of the second portion (85) to which the other end of the third portion (90) is connected is the second long side of the pair of second long sides (86 a, 86 b) of the second portion (85) that is closer to the first long side (81 a) of the first portion (80) to which one end of the third portion (90) is connected.

[0150] -Modification 3 of Embodiment 2- In the connection flow path (75) of this embodiment, one end of the third portion (90) may be connected to a portion of the lower first long side (81b) of the first portion (80). In this modification, one end of the third portion (90) is preferably connected to a portion of the first long side (81b) that includes the midpoint (CP1) of the first long side (81b). In addition, in this modification, one end of the third portion (90) is preferably connected to an area of at least half of the first long side (81b).

[0151] This modification can also be applied to the connection flow path (75) in the first and second modifications of this embodiment.

[0152] -Modification 4 of Embodiment 2- In the connecting flow path (75) of this embodiment, the other end of the third portion (90) may be connected to a portion of the lower second long side (86b) of the second portion (85). In this modification, it is preferable that one end of the third portion (90) be connected to a portion of the second long side (86b) that includes the midpoint (CP2) of the second long side (86b). It is also preferable that one end of the third portion (90) be connected to an area of at least half of the second long side (86b).

[0153] This modification can also be applied to the connection flow path (75) in the first to third modifications of this embodiment.

[0154] Third Embodiment A third embodiment will now be described.

[0155] The air conditioner (10) of this embodiment differs from the air conditioner (10) of embodiment 1 in the configuration of the heat exchanger unit (40). Here, the differences between the heat exchanger unit (40) of this embodiment and the heat exchanger unit (40) of embodiment 1 will be mainly described.

[0156] - Heat transfer tube arrangement - 14, the heat exchanger unit (40) of the present embodiment differs from the heat exchanger unit of the first embodiment in the arrangement of the heat transfer tubes (50) in the heat exchange sections (46, 47, 48). In the heat exchange sections (46, 47, 48) of the present embodiment, the first heat transfer tubes (51) and the second heat transfer tubes (52) closest to the respective first heat transfer tubes (51) are located at different positions in the long-side direction of the fins (53). In the long-side direction of the fins (53), the position of each first heat transfer tube (51) constituting the first tube row (56) is shifted from the position of each second heat transfer tube (52) constituting the second tube row (57) by half the pitch of the first heat transfer tubes (51) in the first tube row (56).

[0157] -Connecting channel of second plate stack- Similar to the first embodiment, the second plate stack (62) of the present embodiment has a connection flow path (75) formed therein. The connection flow path (75) connects one first heat transfer tube (51) to one second heat transfer tube (52) that is closest to the first heat transfer tube (51). The connection flow path (75) of the present embodiment connects one first heat transfer tube (51) to one of the two second heat transfer tubes (52) that are closest to the first heat transfer tube (51), the second heat transfer tube (52) that is located above the first heat transfer tube (51).

[0158] The connection flow path (75) of this embodiment is formed in the same shape as the connection flow path (75) of the first embodiment shown in Fig. 6. Like the connection flow path (75) of the first embodiment, the connection flow path (75) is divided into a first portion (80), a second portion (85), and a third portion (90).

[0159] <Part 1> The first portion (80) of this embodiment has the same shape as the first portion (80) of the first embodiment. Like the first portion (80) of the first embodiment, the first portion (80) of this embodiment overlaps the entire end surface of the first heat transfer tube (51) and covers the end surface of the first heat transfer tube (51). The end surface of the first heat transfer tube (51) faces the first portion (80). All of the in-pipe flow paths (50a) formed in the first heat transfer tube (51) communicate with the first portion (80). The first portion (80) has a pair of first long sides (81a, 81b) and a pair of first semicircular portions (82a, 82b).

[0160] <Second part> The second portion (85) of this embodiment has the same shape as the second portion (85) of the first embodiment. Like the second portion (85) of the first embodiment, the second portion (85) of this embodiment overlaps the entire end surface of the second heat transfer tube (52) and covers the end surface of the second heat transfer tube (52). The end surface of the second heat transfer tube (52) faces the second portion (85). All of the in-pipe flow paths (50a) formed in the second heat transfer tube (52) communicate with the second portion (85). The second portion (85) has a pair of second long sides (86a, 86b) and a pair of second semicircular portions (87a, 87b).

[0161] <3rd part> Similar to the third portion of the first embodiment, the third portion of the present embodiment extends linearly obliquely from the first portion (80) to the second portion (85) and connects the first portion (80) and the second portion (85).

[0162] One end of the third portion 90 is connected to the entire first long side 81a. Therefore, one end of the third portion 90 is connected to a portion of the first long side 81a that includes the midpoint (CP1) of the first long side 81a. The other end of the third portion 90 is connected to the entire second long side 86b. Therefore, the other end of the third portion 90 is connected to a portion of the second long side 86b that includes the midpoint (CP2) of the second long side 86b.

[0163] One end of the third portion (90) is connected to the upper first long side (81 a) of the first portion (80), and the other end of the third portion (90) is connected to the lower second long side (86 b) of the second portion (85). Therefore, the first long side (81 a) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side from the second long side (86 b) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86 b) of the second portion (85) to which the other end of the third portion (90) is connected is the second long side of the pair of second long sides (86 a, 86 b) of the second portion (85) that is closer to the first long side (81 a) of the first portion (80) to which one end of the third portion (90) is connected.

[0164] - Refrigerant flow in the connecting channel - The flow of refrigerant in the connection flow path (75) of this embodiment is similar to the flow of refrigerant in the connection flow path (75) of the first embodiment.

[0165] When the refrigerant flows from the first heat transfer pipe (51) to the second heat transfer pipe (52), the refrigerant flows from the in-pipe flow paths (50a) of the first heat transfer pipe (51) into the first portion (80), passes through the third portion (90), and flows into the second portion (85), and is distributed approximately evenly to all the in-pipe flow paths (50a) formed in the second heat transfer pipe (52).

[0166] When the refrigerant flows from the second heat transfer pipe (52) toward the first heat transfer pipe (51), the refrigerant flows from each in-pipe flow path (50a) of the second heat transfer pipe (52) into the second portion (85), passes through the third portion (90), and flows into the first portion (80), and is distributed approximately evenly to all the in-pipe flow paths (50a) formed in the first heat transfer pipe (51).

[0167] -Features of the third embodiment- In the heat exchanger unit (40) of this embodiment, similarly to the heat exchanger unit (40) of the first embodiment, the refrigerant flowing through the connecting flow path (75) is distributed approximately evenly to all the in-pipe flow paths (50a) formed in the heat transfer tubes (50), and the difference in the flow rate of the refrigerant flowing through the in-pipe flow paths (50a) of one heat transfer tube (50) is kept small. Therefore, according to this embodiment, the performance of the heat exchanger unit (40) can be improved.

[0168] -Modification 1 of Embodiment 3- The connection flow path (75) formed in the second plate stack (62) of this embodiment may connect one first heat transfer tube (51) to one of the two second heat transfer tubes (52) closest to the first heat transfer tube (51), which is located below the first heat transfer tube (51).

[0169] In the connection flow path (75) of this modified example, one end of the third portion (90) is connected to the lower first long side (81b) of the first portion (80). One end of the third portion (90) is connected to the entire first long side (81b). Therefore, one end of the third portion (90) is connected to a portion of the first long side (81b) that includes the midpoint of the first long side (81b).

[0170] In the connection flow path (75) of this modified example, the other end of the third portion (90) is connected to the upper second long side (86a) of the second portion (85). The other end of the third portion (90) is connected to the entire second long side (86a). Therefore, the other end of the third portion (90) is connected to a portion of the second long side (86a) that includes the midpoint of the second long side (86a).

[0171] In the connection flow path (75) of this modified example, one end of the third portion (90) is connected to the lower first long side (81b) of the first portion (80), and the other end of the third portion (90) is connected to the upper second long side (86a) of the second portion (85). Therefore, the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side from the second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected is the second long side of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected.

[0172] -Modification 2 of Embodiment 3- The connection flow path (75) of this embodiment can be applied to the first to third modifications of the first embodiment. That is, the shape of the connection flow path (75) of this embodiment may be the same as the shape of the connection flow path (75) shown in each of FIGS.

[0173] -Modification 3 of Embodiment 3- In the connection flow path (75) of this embodiment, one end of the third portion (90) may be connected to a part of the upper first long side (81 a) of the first portion (80). In this modification, it is preferable that one end of the third portion (90) be connected to a portion of the first long side (81 a) that includes the midpoint (CP1) of the first long side (81 a). It is also preferable that one end of the third portion (90) be connected to an area of at least half of the first long side (81 a).

[0174] This modification can also be applied to the connection flow path (75) in the first and second modifications of this embodiment.

[0175] -Modification 4 of Embodiment 3- In the connecting flow path (75) of this embodiment, the other end of the third portion (90) may be connected to a portion of the lower second long side (86b) of the second portion (85). In this modification, it is preferable that one end of the third portion (90) be connected to a portion of the second long side (86b) that includes the midpoint (CP2) of the second long side (86b). It is also preferable that one end of the third portion (90) be connected to an area of at least half of the second long side (86b).

[0176] This modification can also be applied to the connection flow path (75) of the first to third modifications of this embodiment.

[0177] Other Embodiments The following modifications may be applied to the heat exchanger unit of the above embodiment. The following modifications may be combined or substituted as appropriate as long as the function of the heat exchanger unit is not impaired.

[0178] -First Modification- In each of the above-described first to third embodiments, the second plate stack (62) may include four plate members (65).

[0179] The second plate stack 62 of this modified example will be described with reference to Fig. 16. Fig. 16 shows the second plate stack 62 of the first embodiment to which this modified example is applied. Here, the second plate stack 62 of this modified example will be described, focusing mainly on the differences from the second plate stack 62 of the first embodiment.

[0180] Fig. 16 shows a cross section of a portion of the second plate stack 62 that is connected to the heat transfer tubes 50 of the first heat exchange section 46. In Fig. 16, cross sections 16A-16A and 16B-16B are taken along the cutting lines indicated by cross sections 16C-16C and 16D-16D. Cross sections 16C-16C and 16D-16D are taken along the cutting lines indicated by cross sections 16A-16A and 16B-16B.

[0181] The second plate stack (62) of this modified example includes a base plate (70), a first plate (71), a second plate (72), and a third plate (73). The third plate (73) is a plate member (65). The third plate (73) is formed in a flat plate shape, similar to the base plate (70), the first plate (71), and the second plate (72).

[0182] In the second plate stack (62), a base plate (70), a first plate (71), a second plate (72), and a third plate (73) are arranged in order from the heat transfer tube (50). The base plate (70) is joined to the first plate (71), the first plate (71) is joined to the second plate (72), and the second plate (72) is joined to the third plate (73) by brazing.

[0183] In the second plate stack (62) of this modification, the connecting flow path (75) is formed by both the first plate (71) and the second plate (72). The third plate (73) covers the connecting flow path (75) of the second plate (72) and seals the connecting flow path (75).

[0184] The first portion (80) and the second portion (85) of the connecting flow path (75) are each formed across both the first plate (71) and the second plate (72). The third portion (90) of the connecting flow path (75) is formed in the second plate (72). In this modified example, the third portion (90) is formed only in the second plate (72) of the first plate (71) and the second plate (72).

[0185] -Second modified example- In each of the first to third embodiments, the width Wp1 of the first portion (80) forming the connection flow path (75) may be greater than the width Wt of the first heat transfer pipe (51).

[0186] In each of the first to third embodiments, the width Wp2 of the second portion (85) constituting the connecting flow path (75) may be greater than the width Wt of the second heat transfer pipe (52).

[0187] -Third Modification- In each of the above Embodiments 1 to 3, the first portion (80) constituting the connection flow path (75) may overlap a part of the end surface of the first heat transfer pipe (51). As long as the condition that "the first portion (80) communicates with all of the in-pipe flow paths (50a) formed in the first heat transfer pipe (51)" is satisfied, a part of the end surface of the first heat transfer pipe (51) may be outside the first portion (80).

[0188] -Fourth Modification- In each of the above Embodiments 1 to 3, the second portion (85) constituting the connection flow path (75) may overlap a part of the end surface of the second heat transfer pipe (52). As long as the condition that "the second portion (85) communicates with all of the in-pipe flow paths (50a) formed in the second heat transfer pipe (52)" is satisfied, a part of the end surface of the second heat transfer pipe (52) may be outside the second portion (85).

[0189] -Fifth Modification- In the above first or second embodiment, the connection flow path (75) may connect one first heat transfer tube (51) to one second heat transfer tube (52) located next to the first heat transfer tube (51) two (or three or more) above the first heat transfer tube (51).

[0190] In addition, in the above-mentioned first or second embodiment, the connection flow path (75) may connect one first heat transfer pipe (51) to one second heat transfer pipe (52) located next to the first heat transfer pipe (51) two (or three or more) below the first heat transfer pipe (51).

[0191] -Sixth Modification- In each of the first to third embodiments, the outdoor heat exchanger (22) of the outdoor unit (20) may be formed as a heat exchanger unit (40).

[0192] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate. Furthermore, the terms "first," "second," "third," etc. in the specification and claims are used to distinguish the terms to which these terms are attached, and do not limit the number or order of the terms. [Industrial Applicability]

[0193] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for heat exchanger units, air conditioner indoor units, and refrigeration cycle devices. [Explanation of symbols]

[0194] 10 Air conditioning equipment (refrigeration cycle equipment) 11 Refrigerant circuit () 30 Indoor unit (air conditioning indoor unit) 40 Heat Exchanger Unit 50 Heat transfer tube 50a Pipe flow path 51 First heat transfer tube 52 Second heat transfer tube 53 Finn 56 1st tube row 57 2nd tube row 62 Second plate stack (plate structure) 65 Plate member 71 First plate (first plate member) 72 Second plate (second plate member) 75 connecting flow path 80 Part 1 81a First long side 81b First long side CP1 (midpoint of first long side) 85 Part 2 86a Second long side 86b Second long side CP2 (midpoint of second long side) 90 Part 3 L1 (connecting channel) center line

Claims

1. A heat exchanger unit (40) including a plurality of fins (53) and a plurality of heat transfer tubes (50), wherein a heat medium flowing through the heat transfer tubes (50) exchanges heat with air, Each of the plurality of heat transfer tubes (50) is a flat tube having a plurality of in-pipe flow paths (50a) formed therein, In each of the heat transfer tubes (50), the in-pipe flow paths (50a) are aligned in a line in the width direction of the heat transfer tube (50), The plurality of heat transfer tubes (50) include a plurality of first heat transfer tubes (51) and a plurality of second heat transfer tubes (52), a plurality of the first heat transfer tubes (51) arranged in a row with a gap between them form a first tube row (56), a plurality of the second heat transfer tubes (52) arranged in a row with a gap between them form a second tube row (57), The first tube row (56) and the second tube row (57) are arranged in this order from upstream to downstream of the flow of air passing through the heat exchanger unit (40), a plate structure (62) joined to ends of the heat transfer tubes (50), and having a connecting flow path (75) formed therein for connecting one of the first heat transfer tubes (51) to one of the second heat transfer tubes (52); The connection flow path (75) a first portion (80) facing an end face of the first heat transfer pipe (51) and communicating with all of the in-pipe flow paths (50a) formed in the first heat transfer pipe (51); a second portion (85) facing an end face of the second heat transfer pipe (52) and communicating with all of the in-pipe flow paths (50a) formed in the second heat transfer pipe (52); a third portion (90) communicating with both the first portion (80) and the second portion (85); The first portion (80) has a pair of first long sides (81a, 81b) extending along the width direction of the first heat transfer tube (51), The second portion (85) has a pair of second long sides (86a, 86b) extending along the width direction of the second heat transfer tube (52), one end of the third portion (90) is connected to only one of the pair of first long sides (81a, 81b) of the first portion (80); The other end of the third portion (90) is connected to only one of the pair of second long sides (86a, 86b) of the second portion (85). Heat exchanger unit.

2. The plate structure (62) has a plurality of plate members (65) that are overlapped and joined to one another, The first portion (80), the second portion (85), and the third portion (90) of the connecting flow path (75) are formed on one of the plate members (65).

2. The heat exchanger unit of claim 1.

3. The plate structure (62) has a plurality of plate members (65) that are overlapped and joined to one another, the plurality of plate members (65) include a first plate member (71) and a second plate member (72) located on the opposite side of the first plate member (71) from the heat transfer tube (50); the first portion (80) and the second portion (85) of the connecting flow path (75) are formed across both the first plate member (71) and the second plate member (72); The third portion (90) of the connecting flow path (75) is formed only in the second plate member (72) of the first plate member (71) and the second plate member (72).

2. The heat exchanger unit of claim 1.

4. the width of the first portion (80) is equal to or greater than the width of the first heat transfer tube (51); the width of the second portion (85) is equal to or greater than the width of the second heat transfer tube (52); The width of the third portion (90) is equal to or smaller than the width of the first heat transfer pipe (51) and equal to or smaller than the width of the second heat transfer pipe (52). A heat exchanger unit according to any one of claims 1 to 3.

5. The first long sides (81a, 81b) of the first portion (80) to which one end of the third portion (90) is connected are located on the same side as the second long sides (86a, 86b) of the second portion (85) to which the other end of the third portion (90) is connected. A heat exchanger unit according to any one of claims 1 to 3.

6. The third portion (90) has linear portions (94) formed at positions facing the first long sides (81a, 81b) and the second long sides (86a, 86b).

6. The heat exchanger unit of claim 5.

7. The first long sides (81a, 81b) of the first portion (80) to which one end of the third portion (90) is connected are located on the opposite side to the second long sides (86a, 86b) of the second portion (85) to which the other end of the third portion (90) is connected. A heat exchanger unit according to any one of claims 1 to 3.

8. A center line (L1) in the width direction of the connection flow path (75) is located above a straight line (L2) connecting a midpoint (CP1) of the first long sides (81a, 81b) to which one end of the third portion (90) is connected and a midpoint (CP2) of the second long sides (86a, 86b) to which the other end of the third portion (90) is connected.

8. The heat exchanger unit of claim 7.

9. one end of the third portion (90) is connected to a portion of the first long sides (81a, 81b) that includes a midpoint (CP1) of the first long sides (81a, 81b); The other end of the third portion (90) is connected to a portion of the second long sides (86a, 86b) that includes the midpoint (CP2) of the second long sides (86a, 86b). A heat exchanger unit according to any one of claims 1 to 3.

10. A heat exchanger unit (40) according to any one of claims 1 to 3, The heat exchanger unit (40) exchanges heat between the heat medium and room air. Air conditioning indoor unit.

11. a refrigerant circuit (11) having a heat exchanger unit (40) according to any one of claims 1 to 3; A refrigerant is circulated in the refrigerant circuit (11) to perform a refrigeration cycle. Refrigeration cycle equipment.

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