Indoor unit of air conditioning device, and air conditioning device

Abstract

This indoor unit of an air conditioning device comprises: an indoor heat exchanger (40) including a plurality of fins (41) and a plurality of heat transfer pipes (42); and a first plate structure (50, 60) in which first refrigerant passages (51, 61) are formed. A gas pipe (12a) and / or a liquid pipe (13a) is connected to one ends (A) of the heat transfer pipes (42). The first refrigerant passages (51, 61) are connected to the other ends (B) of the transfer pipes (42). The first refrigerant passages (51, 61) include a first passage connected to a first other end and a second other end among a plurality of the other ends (B), and a second passage connected to a third other end and a fourth other end among the plurality of other ends (B). The interval between the first other end and the second other end is different from the interval between the third other end and the fourth other end.

Description

Indoor unit of an air conditioner and an air conditioner

[0001] The present disclosure relates to an indoor unit of an air conditioner and an air conditioner.

[0002] Patent Document 1 discloses an air conditioner. The air conditioner described in Patent Document 1 includes a heat exchange unit. The heat exchange unit includes a heat transfer pipe, fins joined to the heat transfer pipe, a turning part, and a stacked header. A stacked header is connected to one end of the heat transfer pipe. A refrigerant pipe (gas pipe or liquid pipe) is connected to the stacked header. A turning part is connected to the other end of the heat transfer pipe. The turning part is formed in a substantially U shape and connects the other ends of adjacent heat transfer pipes.

[0003] International Publication No. 2017 / 042866

[0004] However, when connecting the other ends of the heat transfer pipes by the turning part, the connection destination of the other end is limited to the adjacent other end, so the degree of freedom of the connection destination (routing) of the other end decreases.

[0005] An object of the present disclosure is to improve the degree of freedom of the connection destination of the other ends of the heat transfer pipes when connecting the other ends of the heat transfer pipes.

[0006] The first embodiment relates to an indoor unit of an air conditioning system. The indoor unit of the air conditioning system comprises an indoor heat exchanger (40) including a plurality of fins (41) and a plurality of heat transfer tubes (42) attached to the plurality of fins (41), and a first plate structure (50, 60) in which a first refrigerant passage (51, 61) is formed inside, and each of the plurality of heat transfer tubes (42) includes one end (A) located on one side (Z1) of the arrangement direction (Z) of the plurality of fins (41) and the other end (B) located on the other side (Z2) of the arrangement direction (Z), and the one end (A) is connected to the indoor heat exchanger (40) and the outdoor heat exchanger (22). At least one of the following gas pipes (12a) and liquid pipes (13a) is connected, and the other end (B) is connected to the first refrigerant passage (51, 61) of the first plate structure (50, 60), and the first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a first passage connected to the first and second other end of the plurality of other end (B), and a second passage connected to the third and fourth other end of the plurality of other end (B), wherein the distance between the first and second other end is different from the distance between the third and fourth other end.

[0007] In the first embodiment, by connecting the other ends (B) of the heat transfer tubes (42) via the first refrigerant passages (51, 61), the combination of the other ends (B) that are connected to each other can be changed according to the shape of the first refrigerant passages (51, 61), thereby improving the degree of freedom in the connection destination (path) of the other ends (B).

[0008] The second aspect indicates that, in the first aspect, the distance between the first other end and the second other end is different from the distance between the third other end and the fourth other end, which means that the distance dimension (D1) between the first other end (B12) and the second other end (B13) is different from the distance dimension (D2) between the third other end (B22) and the fourth other end (B33).

[0009] In the second embodiment, the other ends (B) can be connected to each other in such a way that the spacing between them is not the same.

[0010] The third aspect indicates that, in the first or second aspect, the distance between the first other end and the second other end is different from the distance between the third other end and the fourth other end, which means that the alignment direction (Y1) of the first other end (B11) and the second other end (B21) is different from the alignment direction (Y2) of the third other end (B22) and the fourth other end (B14).

[0011] In the third embodiment, the other ends (B) can be connected to each other in such a way that the arrangement of each of the other ends (B) that are connected to each other is not the same.

[0012] The fourth embodiment is that, in any one of the first to third embodiments, the indoor unit of the air conditioner is provided with a diversion pipe (71) that connects the gas pipe (12a) or the liquid pipe (13a) to three or more of the end portions (A14, A24, A34, A44), and the three or more end portions (A14, A24, A34, A44) are adjacent to each other.

[0013] In the fourth embodiment, when connecting liquid pipes (13a) or gas pipes (12a) to one end (A) of three or more heat transfer tubes (42) via a diversion pipe (71), by connecting them to one end (A) of adjacent heat transfer tubes (42), three or more different heat transfer tubes (42) can be arranged so that the supercooled or heated regions are adjacent to each other. As a result, the performance degradation of the indoor heat exchanger (40) due to heat conduction can be suppressed.

[0014] The fifth embodiment is one of the first to fourth embodiments, wherein the first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a third passage (51e) that connects the other end (B14) of a single heat transfer tube (42) to which the gas pipe (12a) or the liquid pipe (13a) is connected at one end (A), and a plurality of other ends (B21, B22) of the single heat transfer tube (42) other than the other end (B14).

[0015] In the fifth embodiment, the refrigerant supplied from one end (A) can be divided and distributed to multiple other ends (B14) via a third passage (51e).

[0016] The sixth aspect is that, in any one of the first to fifth aspects, the indoor heat exchanger (40) includes a first heat exchange section (43a) and a second heat exchange section (43b) connected to the first heat exchange section (43a), and is bent at the point where the first heat exchange section (43a) and the second heat exchange section (43b) are connected, and the first refrigerant passage (51) of the first plate structure (50) includes a fourth passage (51j, 51k) connecting the other end (B51, B54) of the heat transfer tube (42) arranged in the first heat exchange section (43a) and the other end (B52, B53) of the heat transfer tube (42) arranged in the second heat exchange section (43b).

[0017] In the sixth embodiment, even when the heat exchange section has a bent shape, the degree of freedom for connecting to the other end (B) can be improved.

[0018] The seventh aspect is that, in the sixth aspect, the indoor unit of the air conditioner does not include refrigerant piping connecting one end (A) of the heat transfer tube (42) located in the first heat exchange section (43a) and one end (A) of the heat transfer tube (42) located in the second heat exchange section (43b).

[0019] In the seventh embodiment, the piping structure for supplying refrigerant between the two ends (A) can be simplified.

[0020] The eighth aspect is that, in any one of the first to seventh aspects, the first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a fifth passage (51f) that connects the other ends (B11, B32) located at one or more stages apart in the heat exchange path.

[0021] In the eighth embodiment, the connection destination of the other end (B) is not limited to an adjacent other end (B), and the degree of freedom of the connection destination of the other end (B) can be improved.

[0022] The ninth aspect is that, in the eighth aspect, the indoor unit of the air conditioner is provided with refrigerant piping (48) that connects the one ends (A) of the heat transfer tubes (42), and the refrigerant piping (48) does not connect the one ends (A) that are located at one or more stages apart in the heat exchange path.

[0023] In the ninth embodiment, the piping structure for supplying refrigerant between the two ends (A) can be simplified.

[0024] The tenth embodiment is one of the first to ninth embodiments, wherein the first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a sixth passage (51g) that branches off and is connected to three or more of the other ends (B31, B43, B44).

[0025] In the tenth embodiment, the connection destination of the other end (B) is not limited to an adjacent other end (B), and the degree of freedom of the connection destination of the other end (B) can be improved.

[0026] In the eleventh embodiment, in any one of the first to tenth embodiments, the indoor unit of the air conditioner is provided with a refrigerant pipe (73) connecting the one ends (A) of the heat transfer tubes (42), wherein the refrigerant pipe (73) connects the one end (A) of a single first heat transfer tube (42) to the one end (A) of a single second heat transfer tube (42).

[0027] In the eleventh embodiment, the structure of the refrigerant piping (73) can be simplified.

[0028] The twelfth aspect is that, in any one of the first to eleventh aspects, the first refrigerant passages (51, 61) of the first plate structure (50, 60) include seventh refrigerant passages (51h, 51, 51i) that intersect each other when viewed in the arrangement direction (Z).

[0029] In the twelfth embodiment, the degree of freedom of the connection destination of the other ends (B) can be improved by connecting the other ends (B) using the seventh refrigerant passages (51h, 51, 51i) that intersect with each other.

[0030] The thirteenth embodiment is that, in any one of the first to twelfth embodiments, the indoor unit of the air conditioner comprises a first pipe (73) connecting the first end (A) and a second pipe (73) connecting the second end (A), wherein the first pipe (73) and the second pipe (73) do not intersect when viewed in the arrangement direction (Z).

[0031] In the 13th embodiment, the piping structure for supplying refrigerant between the two ends (A) can be simplified by not having a structure in which the pipes (73) intersect.

[0032] In the fourteenth embodiment, in any one of the first to thirteenth embodiments, the indoor unit of the air conditioner includes a second plate structure (81, 82) in which a second refrigerant passage is formed, and the second refrigerant passage of the second plate structure (81, 82) is connected to one end (A).

[0033] In the 14th embodiment, the total space occupied by the indoor heat exchanger (40) can be reduced, and the design flexibility of the indoor unit can be improved.

[0034] In the fifteenth embodiment, in any one of the first to fourteenth embodiments, the first plate structure (50, 60) is brazed to the plurality of heat transfer tubes (42).

[0035] In the 15th embodiment, the joint between the first plate structure (50, 60) and the heat transfer tube (42) can be sealed, thereby reducing the risk of refrigerant leakage.

[0036] The sixteenth aspect is that, in any one of the first to fifteenth aspects, the heat transfer tube (42) is a flattened multi-hole tube.

[0037] In the sixteenth embodiment, the heat transfer area by the heat transfer tube (42) is increased, enabling efficient heat exchange and improving heating and cooling performance.

[0038] The seventeenth aspect is that, in any one of the first to sixteenth aspects, the first plate structure (50, 60) includes five or fewer stacked plate-shaped members.

[0039] In the 17th embodiment, the total space occupied by the indoor heat exchanger (40) can be reduced, and the design flexibility of the indoor unit can be improved.

[0040] The eighteenth embodiment is the seventeenth embodiment, wherein each of the five or fewer plate-shaped members has a thickness of 3 mm or less.

[0041] In the 18th aspect, the occupied space of the entire indoor heat exchanger (40) can be reduced, and the degree of freedom in the design of the indoor unit can be improved.

[0042] In the 19th aspect, in any one of the 1st to 18th aspects, a tube sheet (49) that supports the other direction side (Z2) of the plurality of heat transfer tubes (42) is provided, and the distance dimension between the tube sheet (49) and the first plate structure (50, 60) is 30 mm or less.

[0043] In the 19th aspect, the occupied space of the entire indoor heat exchanger (40) can be reduced, and the degree of freedom in the design of the indoor unit can be improved.

[0044] The 20th aspect is directed to an air conditioner. The air conditioner includes an indoor unit according to any one of the 1st to 19th aspects.

[0045] Figure 1 is a piping diagram of an air conditioning system according to an embodiment. Figure 2 is a front view of the indoor unit of the air conditioner. Figure 3 is a cross-sectional view of the indoor unit of the air conditioner. Figure 4 is a front view showing the internal structure of the indoor unit of the air conditioner. Figure 5 is a perspective view showing the connection part of the indoor heat exchanger. Figure 6 is a perspective view showing the plate structure. Figure 7 is a cross-sectional view of the plate structure. Figure 8A is a schematic diagram showing the other end of a heat transfer tube connected to the plate structure and a refrigerant passage connecting the other ends. Figure 8B is a schematic diagram showing the other end of a heat transfer tube connected to the plate structure and a refrigerant passage connecting the other ends. Figure 9 is a schematic diagram showing a configuration in which adjacent other ends are connected in the step direction. Figure 10 is a schematic diagram showing a configuration in which adjacent other ends are connected in the column direction. Figure 11 is a schematic diagram showing the other end of a heat transfer tube connected to the plate structure and a refrigerant passage connecting the other ends. Figure 12A is a schematic diagram showing an example of a configuration in which one end of a heat transfer tube is connected to the other end. Figure 12B is a schematic diagram showing a fourth example of the other end of a heat transfer tube connected to a plate structure and a refrigerant passage connecting the other ends. Figure 13 is a schematic diagram showing a fifth example of the other end of a heat transfer tube connected to a plate structure and a refrigerant passage connecting the other ends. Figure 14 is a perspective view showing a modified connection. Figure 15 is a perspective view showing a modified heat transfer tube. Figure 16 is a diagram showing a modified arrangement of multiple heat transfer tubes.

[0046] The embodiments of this disclosure will be described in detail below with reference to the drawings. However, this disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of ​​this disclosure. Since the drawings are for conceptual illustration of this disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for ease of understanding.

[0047] (1) Overall configuration of the air conditioning system This embodiment is an air conditioning system (10) equipped with a heat exchanger unit. The air conditioning system (10) adjusts the temperature of the air in the indoor space (I), which is the target space.

[0048] 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. The refrigerant circuit (11) performs a refrigeration cycle by circulating the refrigerant.

[0049] The air conditioner (10) includes an outdoor unit (20), an indoor unit (30), a first connection pipe (12), and a second connection pipe (13). The air conditioner (10) has one or more outdoor units (20) and one or more indoor units (30). In the present embodiment, the air conditioner (10) is a paired type having one outdoor unit (20) and one indoor unit (30). The first connection pipe (12) is a gas connection pipe, and the second connection pipe (13) is a liquid connection pipe.

[0050] The outdoor unit (20) is installed outdoors. The outdoor unit (20) includes an outdoor casing (20a), a compressor (21) housed in the outdoor casing (20a), an outdoor heat exchanger (22), an outdoor expansion valve (23), a four-way switching valve (24), and an outdoor fan (25).

[0051] The compressor (21) is a rotary compressor such as a swing piston type, a rotary type, or a scroll type. The outdoor heat exchanger (22) exchanges heat between the refrigerant and outdoor air. The outdoor heat exchanger (22) is of a fin-and-tube type. The outdoor expansion valve (23) reduces the pressure of the refrigerant. The outdoor expansion valve (23) is an electronic expansion valve. The four-way switching valve (24) switches between a first state (the state shown by the solid line in FIG. 1) and a second state (the state shown by the broken line in FIG. 1). The four-way switching valve (24) in the first state connects the discharge part of the compressor (21) and the gas end of the outdoor heat exchanger (22), and connects the suction part of the compressor (21) and the first connection pipe (12). The four-way switching valve (24) in the second state connects the discharge part of the compressor (21) and the first connection pipe (12), and connects the suction part of the compressor (21) and the gas end of the outdoor heat exchanger (22). The outdoor fan (25) conveys the air flowing through the outdoor heat exchanger (22). The outdoor fan (25) is a propeller fan.

[0052] The indoor unit (30) includes a casing (31), an indoor heat exchanger (40) housed in the casing (31), an indoor fan (32), and an indoor expansion valve (37).

[0053] (2) Indoor unit of the air conditioner The details of the indoor unit (30), which is an indoor air conditioner, will be explained with reference to Figures 2 to 4. The indoor unit (30) of this embodiment is a wall-mounted type installed on the wall of the indoor space (I). The terms "up," "down," "right," "left," "front," and "back" described below correspond to the directions of the arrows shown in Figures 2 and 3, and the left and right directions are based on the view of the indoor casing (31) from the front.

[0054] (2-1) Casing As shown in Figures 2 and 3, the casing (31) is formed in a horizontally elongated box shape.

[0055] An intake port (33) is formed at the top of the casing (31), and an outlet port (34) is formed at the bottom of the casing (31). Inside the casing (31), an air passage (P) is formed from the intake port (33) to the outlet port (34). The intake port (33) extends in the longitudinal direction of the casing (31). The intake port (33) is an opening for drawing air from the indoor space into the air passage (P). The outlet port (34) extends in the longitudinal direction of the casing (31). The outlet port (34) is an opening for blowing the air from the air passage (P) into the indoor space.

[0056] (2-2) The indoor unit (30) is equipped with a filter (35). The filter (35) is located behind the intake port (33) and upstream of the indoor heat exchanger (40). The filter (35) collects dust from the air sent from the intake port (33) to the indoor heat exchanger (40). The indoor unit (30) may be equipped with a dust removal mechanism to remove the dust collected by the filter (35).

[0057] (2-3) Heat Exchanger Unit The heat exchanger unit (U) comprises one indoor heat exchanger (40) and one indoor expansion valve (37). The indoor heat exchanger (40) comprises one heat exchanger body (4X) and two plate structures (50, 60). The heat exchanger body (4X) of the indoor heat exchanger (40) is arranged to cross an air passage (P). The air passage (P) is divided into an upstream side and a downstream side of the heat exchanger body (4X). The plate structures (50, 60) are examples of the first plate structure.

[0058] (2-4) Indoor fan The indoor fan (32) is located in the air passage (P). The indoor fan (32) is located downstream of the indoor heat exchanger (40) in the air passage (P). The indoor fan (32) is a cross-flow fan. The fan rotor of the indoor fan (32) extends in the longitudinal direction of the casing (31).

[0059] (2-5) The flap indoor unit (30) has a flap (36) that adjusts the direction of the air blown out from the air outlet (34). The flap (36) adjusts the airflow direction in the vertical direction. The indoor unit (30) may have a plurality of flaps (36). The flap (36) may adjust the airflow direction in the horizontal direction.

[0060] (3) Heat exchanger unit The heat exchanger unit (U) comprises an indoor heat exchanger (40), an indoor expansion valve (37), a gas pipe (12a), a liquid pipe (13a), and a connection part (70). The gas pipe (12a) and the liquid pipe (13a) connect the indoor heat exchanger (40) and the outdoor heat exchanger (22).

[0061] (3-1) Indoor heat exchanger The indoor heat exchanger (40) shown in Figures 3 to 6 comprises a heat exchanger body (4X) and plate structures (50, 60) connected to the heat exchanger body (4X). The indoor heat exchanger (40) is a fin-and-tube type heat exchanger having fins (41) and heat transfer tubes (42). The indoor heat exchanger (40) exchanges heat between air and a refrigerant.

[0062] The heat exchanger body (4X) has a plurality of fins (41) arranged in the longitudinal direction of the casing (31) and a plurality of heat transfer tubes (42) extending along the direction (Z) of the arrangement of the plurality of fins (41). The plate structures (50, 60) have refrigerant passages (51, 61) (first refrigerant passages) inside that communicate with the other ends (B) of the heat transfer tubes (42).

[0063] The arrangement direction (Z) of the multiple fins (41) corresponds to the longitudinal direction (in this case, left-right direction) of the casing (31). The fins (41) are rectangular plates with a long side and a short side. The thickness direction of the fins (41) corresponds to the arrangement direction (Z) of the multiple fins (41). The multiple fins (41) are arranged at predetermined intervals in their thickness direction (arrangement direction (Z)). This interval constitutes an air passage. The material of the fins (41) is, for example, an aluminum alloy.

[0064] The heat transfer tubes (42) are straight tubes. The material of the multiple heat transfer tubes (42) is, for example, an aluminum alloy. A coolant passage is formed inside the heat transfer tubes (42). Each of the multiple heat transfer tubes (42) extends along the alignment direction (Z). The multiple heat transfer tubes (42) (multiple one end (A) and multiple other end (B)) are arranged in multiple stages along the step direction (up and down direction in Figure 8A) and in multiple rows along the column direction (direction of air passage) that intersects the longitudinal direction of the heat transfer tubes (42). The multiple heat transfer tubes (42) are arranged adjacent to each other in a staggered manner (see Figure 8A). Each of the multiple heat transfer tubes (42) is attached to multiple fins (41). Each of the multiple heat transfer tubes (42) is arranged parallel to each other while passing through the multiple fins (41) along the alignment direction (Z). Each of the multiple heat transfer tubes (42) includes one end (A) located on one side (Z1) of the arrangement direction (Z) and the other end (B) located on the other side (Z2) of the arrangement direction (Z).

[0065] The right end (A) of the heat transfer tube (42) protrudes to the right of the fin (41). The right end (A) of the heat transfer tube (42) is connected to a gas pipe (12a) or a liquid pipe (13a).

[0066] The left end (B) of each of the multiple heat transfer tubes (42) protrudes to the left of the fin (41). The multiple other ends (B) are connected to the plate structures (50, 60).

[0067] The connection section (70) is a mechanism for connecting different end portions (A) of a plurality of end portions (A) to each other, and for connecting a gas pipe (12a) or a liquid pipe (13a) to any of the plurality of end portions (A). The connection section (70) includes a flow divider (71) for branching the gas pipe (12a) or liquid pipe (13a), a connecting pipe (72) connected to the flow divider (71) and one end portion (A) of the heat transfer tube (42), and a U-shaped pipe (73). The U-shaped pipe (73) connects one end portion (A) of a single first heat transfer tube (42) to one end portion (A) of a single second heat transfer tube (42). The U-shaped pipe (73) connects adjacent end portions (A) of a plurality of end portions (A) to each other. In other words, the U-shaped pipe (73) does not connect end portions (A) that are located at a distance of one or more stages in the heat exchange path.

[0068] Two or more of the multiple end portions (A) are connected to a gas pipe (12a) or liquid pipe (13a) via a flow divider (71) and connecting piping (72). At the end portions (A) other than those connected to the gas pipe (12a) or liquid pipe (13a), two adjacent end portions (A) are connected via a U-shaped pipe (73). Two end portions (A) being adjacent means that the two end portions (A) are adjacent in the step direction or row direction, and no other end portion (A) is located between the two end portions (A).

[0069] The indoor heat exchanger (40) of this embodiment includes a heat exchange section. The heat exchange section has a front heat exchange section (40A), which is a first heat exchange section, and a rear heat exchange section (40B), which is a second heat exchange section. The front heat exchange section (40A) is located towards the front of the casing (31), and the rear heat exchange section (40B) is located towards the rear of the casing (31). The front heat exchange section (40A) and the rear heat exchange section (40B) are arranged in a direction perpendicular to both the vertical direction and the axial direction of the heat transfer tubes (42), i.e., in the front-to-back direction, so as to sandwich the indoor fan (32).

[0070] The front heat exchange section (40A) includes a front main heat exchange section (43), a first auxiliary heat exchange section (44), a second auxiliary heat exchange section (45), and a tube sheet (49).

[0071] The tube sheet (49) is positioned so that its surface is aligned vertically and horizontally, and is located to the left of the multiple fins (41). The tube sheet (49) faces the front plate structure (50). Multiple heat transfer tubes (42) pass through the tube sheet (49). There is almost no gap between the tube sheet (49) and each heat transfer tube (42), and the tube sheet (49) supports the fins (41) and the multiple heat transfer tubes (42). The U-shaped tube (73) front plate structure (50) is positioned to the left of the tube sheet (49), that is, on the side opposite the multiple fins (41) to the tube sheet (49). The distance dimension (E) (dimension in the arrangement direction (Z)) between the tube sheet (49) and the front plate structure (50) may be 30 mm or less. This allows the indoor heat exchanger (40) to be formed compactly. As a result... This reduces the overall space occupied by the indoor heat exchanger (40) and improves the design flexibility of the indoor unit (30).

[0072] The front main heat exchange section (43) is positioned closer to the indoor fan (32) in the front heat exchange section (40A). The outer shape of the front main heat exchange section (43) is formed in a V shape when viewed from the longitudinal direction of the heat transfer tubes (42). The tip of this V shape points forward.

[0073] The first auxiliary heat exchange section (44) is provided on the inlet side (front side) of the first front main heat exchange section (43a). The second auxiliary heat exchange section (45) is provided on the inlet side (front side) of the second front main heat exchange section (43b). The rear heat exchange section (40B) has a rear main heat exchange section (46), a third auxiliary heat exchange section (47), and a tube sheet. The rear main heat exchange section (46) is positioned closer to the indoor fan (32) in the rear heat exchange section (40B). The third auxiliary heat exchange section (47) is provided on the inlet side (rear side) of the rear main heat exchange section (46). The tube sheet of the rear heat exchange section (40B) faces the rear plate structure (60). The distance between the tube sheet of the rear heat exchange section (40B) and the rear plate structure (60) may be 30 mm or less.

[0074] As shown in Figures 3, 4, 6, and 7, the other end (B) of the heat transfer tube (42) is connected to the connecting tubes (53, 63) of the plate structure (50, 60).

[0075] The plate structure (50,60) is positioned to the left of the leftmost fin (41), parallel to the fin (41). The plate structure (50,60) is connected to the other end (B) of the heat transfer tube (42). As shown in Figure 6, the plate structure (50,60) includes a front plate structure (50) connected to the heat transfer tube (42) of the front heat exchange section (40A), and a rear plate structure (60) connected to the heat transfer tube (42) of the rear heat exchange section (40B). The front plate structure (50) is positioned to overlap with the front heat exchange section (40A) in the axial direction of the heat transfer tube (42). The rear plate structure (60) is positioned to overlap with the rear heat exchange section (40B) in the axial direction of the heat transfer tube (42).

[0076] (3-2) Indoor expansion valve, gas pipe, liquid pipe As shown in Figures 1, 4 and 5, the indoor expansion valve (37) is an electronically controlled expansion valve with a variable opening. The indoor expansion valve (37) is connected to one end (A) of the heat transfer tube (42) of the front heat exchange section (40A) via the first internal piping (38), and to one end (A) of the heat transfer tube (42) of the rear heat exchange section (40B) via the second internal piping (39) (see Figure 1).

[0077] One end of the gas pipe (12a) is connected via a flow divider (71, 71a) to one end (A) of a plurality of heat transfer tubes (42) in the rear heat exchange section (40B). The other end of the gas pipe (12a) is connected to the first connecting pipe (12) via a fitting. One end of the liquid pipe (13a) is connected via a flow divider (71, 71b) to one end (A) of a plurality of heat transfer tubes (42) in the front heat exchange section (40A). The other end of the liquid pipe (13a) is connected to the second connecting pipe (13) via a fitting.

[0078] (4) Plate Structure Details of the plate structure (50, 60) will be explained with reference to Figures 3, 6 and 7.

[0079] (4-1) Front plate structure The front plate structure (50) includes a front main body (52) having a refrigerant passage (51) inside, and a plurality of front connecting pipes (53) that connect the other ends (B) of a plurality of heat transfer tubes (42) of the front heat exchange section (40A) to the refrigerant passage (51).

[0080] As shown in Figures 6 and 7, in this embodiment, the front main body (52) is a thick plate-like member formed by stacking a plurality (five) of front plates. The front plates are plate-shaped members. The stacking direction of the front plates is the same as the axial direction (arrangement direction (Z)) of the heat transfer tubes (42). In the front plate structure (50), the first front plate (521), the second front plate (522), the third front plate (523), the fourth front plate (524), and the fifth front plate (525), all of which are plate-shaped members, are stacked in order from the side closest to the front heat exchange section (40A). The second front plate (522), the third front plate (523), and the fourth front plate (524) are intermediate plates sandwiched between the first front plate (521) and the fifth front plate (525). Holes are formed in each of the multiple front plates that constitute the intermediate plate of the front plate structure (50), and these multiple holes communicate with each other to form a refrigerant passage (51) of the front plate structure (50). At this time, the shape of the refrigerant passage (51) can be changed by appropriately changing the shape of the holes formed in the front plates. As a result, when connecting the other ends (B) via the refrigerant passage (51), the connection destination of the other ends (B) (the combination of other ends (B) that are connected to each other) can be changed according to the shape of the refrigerant passage (51) (i.e., the shape of the holes formed in the front plates). Note that the number of front plates is just an example, and the number of front plates may be four or fewer, or six or more. Note that if the number of front plates is five or fewer, it is possible to maintain the degree of freedom in forming the refrigerant passage (51) of the front plate structure (50) while contributing to the miniaturization of the casing (31). Therefore, it is preferable that the number of front plates be five or fewer. Hereafter, when it is not necessary to distinguish between the different front plates, they will simply be referred to as "front plates."

[0081] The front connecting pipe (53) is fixed to the first front plate (521). The front connecting pipe (53) may be seamlessly molded integrally with the first front plate (521).

[0082] (4-2) Rear plate structure The rear plate structure (60) includes a rear main body (62) having a refrigerant passage (61) inside, and a plurality of rear connecting pipes (63) that connect a plurality of heat transfer tubes (42) of the rear heat exchange section (40B) to the refrigerant passage (61).

[0083] The rear main body (62) is basically the same as the front main body (52), except that the shape of the outer edge of the plate as viewed from the axial direction of the heat transfer tubes (42) and the internal coolant passage (61) are different from those of the front main body (52). The rear main body (62) is a thick plate-like member formed by stacking multiple (five) rear plates. The rear plates are plate-shaped members. The stacking direction of the rear plates is the same as the axial direction of the heat transfer tubes (42). In the rear plate structure (60), the first rear plate (621), the second rear plate (622), the third rear plate (623), the fourth rear plate (624), and the fifth rear plate (625), all of which are plate-shaped members, are stacked in order from the side closest to the rear heat exchange section (40B). The second rear plate (622), the third rear plate (623), and the fourth rear plate (624) are intermediate plates sandwiched between the first rear plate (621) and the fifth rear plate (625). Holes are formed in each of the multiple front plates that constitute the intermediate plate of the rear plate structure (60), and these multiple holes communicate with each other to form a refrigerant passage (61) of the rear plate structure (60). At this time, the shape of the refrigerant passage (61) can be changed by appropriately changing the shape of the holes formed in the rear plates. As a result, when connecting the other ends (B) via the refrigerant passage (61), the connection destination of the other ends (B) (combinations of other ends (B) that are connected to each other) can be changed according to the shape of the refrigerant passage (61) (i.e., the shape of the holes formed in the rear plates). Note that the number of rear plates is just an example, and the number of rear plates may be four or fewer, or six or more. Furthermore, if the number of rear plates is five or less, it is possible to contribute to miniaturizing the casing (31) while maintaining the degree of freedom in forming the refrigerant passages (61) of the rear plate structure (60). Therefore, it is preferable that the number of rear plates be five or less. The number of front plates and the number of rear plates may be different. Hereinafter, when it is not necessary to distinguish each rear plate, it will simply be referred to as a rear plate.

[0084] (5) Operation The air conditioning system (10) performs cooling operation, heating operation and dehumidification operation.

[0085] (5-1) Cooling Operation As shown in Figure 1, during cooling operation, the controller of the air conditioning unit (10) operates the compressor (21), the outdoor fan (25), and the indoor fan (32), sets the four-way switching valve (24) to the first state (the state shown by the solid line in Figure 1), adjusts the opening degree of the outdoor expansion valve (23) as appropriate, and fully opens the indoor expansion valve (37).

[0086] During cooling operation, the refrigerant circuit (11) performs a refrigeration cycle in which the outdoor heat exchanger (22) functions as a condenser (heat radiator) and the indoor heat exchanger (40) functions as an evaporator.

[0087] The indoor unit (30) draws indoor air from the indoor space (I) into the air passage (P) via the intake port (33). The air in the air passage (P) is cooled by the indoor heat exchanger (40). The cooled air is supplied to the indoor space (I) from the outlet (34).

[0088] (5-2) Heating Operation In heating operation, the controller of the air conditioning unit (10) operates the compressor (21), the outdoor fan (25), and the indoor fan (32), sets the four-way switching valve (24) to the second state (the state shown by the dashed line in Figure 1), adjusts the opening of the outdoor expansion valve (23) to a predetermined opening, and fully opens the indoor expansion valve (37).

[0089] During heating operation, the refrigerant circuit (11) performs a refrigeration cycle in which the indoor heat exchanger (40) functions as a condenser (radiator) and the outdoor heat exchanger (22) functions as an evaporator.

[0090] The indoor unit (30) draws indoor air from the indoor space (I) into the air passage (P) via the intake port (33). The air in the air passage (P) is heated by the indoor heat exchanger (40). The heated air is supplied to the indoor space (I) from the outlet (34).

[0091] (5-3) Dehumidification Operation In dehumidification operation, the controller of the air conditioning unit (10) operates the compressor (21), the outdoor fan (25), and the indoor fan (32), sets the four-way switching valve (24) to the first state (the state shown by the solid line in Figure 1), and adjusts the opening of the outdoor expansion valve (23) and the indoor expansion valve (37) as appropriate.

[0092] During dehumidification operation, the refrigerant circuit (11) performs a refrigeration cycle in which the outdoor heat exchanger (22) and the front heat exchange section (40A) of the indoor heat exchanger (40) function as condensers (heat radiators), and the rear heat exchange section (40B) of the indoor heat exchanger (40) functions as an evaporator.

[0093] The indoor unit (30) draws indoor air from the indoor space (I) into the air passage (P) via the intake port (33). The rear heat exchange unit (40B) cools the air in the air passage (P) to below the dew point temperature. The front heat exchange unit (40A) heats the air in the air passage (P). The air that has passed through both heat exchange units mixes in the air passage (P), resulting in air with low humidity. This dehumidified air is then supplied to the indoor space (I) from the outlet (34).

[0094] (6) Features of the indoor unit Conventionally, when connecting the other ends (B) of multiple heat transfer tubes (42), a U-shaped pipe (73) was used. When connecting the other ends (B) via a U-shaped pipe (73), only adjacent other ends (B) in the row direction or column direction could be connected. In contrast, the indoor unit (30) of this embodiment connects each other end (B) of multiple heat transfer tubes (42) to a front plate structure (50), and connects the other ends (B) via a refrigerant passage (51) of the front plate structure (50). As a result, by appropriately forming the refrigerant passage (51), it is possible to connect not only adjacent other ends (B) but also non-adjacent other ends (B), thereby improving the degree of freedom in the connection destination (path) of the other ends (B).

[0095] The indoor unit (30) of this embodiment has the following features. The following features utilize a configuration that improves the degree of freedom of connection to the other end (B) by using the refrigerant passage (51) of the front plate structure (50) when connecting the other end (B) to each other.

[0096] In the indoor unit (30), the refrigerant passage (51) of the front plate structure (50) includes a first passage connected to a first and second other end of a plurality of other ends (B), and a second passage connected to a third and fourth other end of a plurality of other ends, wherein the distance between the first and second other ends is different from the distance between the third and fourth other ends. That is, a feature of the indoor unit (30) of this embodiment is that the distance between the first and second other ends is different from the distance between the third and fourth other ends. Hereinafter, "the distance between the first and second other ends is different from the distance between the third and fourth other ends" may be simply described as "the distance between the other ends (B) is different." The distance between the other ends (B) is different corresponds to the first example or the second example below. The indoor unit (30) includes the configuration of the first example or the configuration of the second example. The first and second examples will be explained with reference to Figures 8A and 8B. In Figures 8A to 8B, the dotted lines connecting the other ends (B) indicate refrigerant passages (51, 61). Furthermore, refrigerant passages (51a) to (51k), which will be described later, are included in refrigerant passage (51).

[0097] (6-1) First Example In the first example, the difference in the spacing of the other ends (B) means that the first spacing dimension is different from the second spacing dimension. The first spacing dimension is the spacing dimension between the first other end and the second other end. The second spacing dimension is the spacing dimension between the third other end and the fourth other end. The spacing dimension is the shortest distance between the centers of the other ends (B).

[0098] Figure 8A shows a first example of a configuration with different spacings for the other ends (B). As shown in Figure 8A, the multiple other ends (B) include other end (B11) to other end (B14), other end (B21) to other end (B24), other end (B31) to other end (B34), and other end (B41) to other end (B44). In Figure 8A, if the refrigerant passage (51a) is the first passage, the refrigerant passage (51b) is the second passage, other end (B12) is the first other end, other end (B13) is the second other end, other end (B22) is the third other end, and other end (B33) is the fourth other end, then the first spacing dimension (D1) between other end (B12) and other end (B13) is different from the second spacing dimension (D2) between other end (B22) and other end (B33). In this embodiment, the other end (B12) and the other end (B13) are adjacent in the step (step direction) of the heat exchange path, and the other end (B22) and the other end (B33) are separated by one step in the heat exchange path (one other end (B23) is located there), so the second spacing dimension (D2) is larger than the first spacing dimension (D1) (D2 > D1).

[0099] (6-2) Second Example In the second example, the difference in the spacing of the other ends (B) means that the first alignment direction is different from the second alignment direction. The first alignment direction is the alignment direction between the first other end and the second other end. The second alignment direction is the alignment direction between the third other end and the fourth other end. The alignment direction is the direction in which the imaginary line connecting the centers of the other ends (B) extends.

[0100] Figure 8B shows a second example of a configuration with different spacing between the other ends (B). In Figure 8B, if the refrigerant passage (51c) is the first passage, the refrigerant passage (51d) is the second passage, the other end (B11) is the first other end, the other end (B21) is the second other end, the other end (B22) is the third other end, and the other end (B14) is the fourth other end, then the first alignment direction (Y1) between the other ends (B11) and (B21) is different from the second alignment direction (Y2) between the other ends (B22) and (B14). In this embodiment, the first alignment direction (Y1) is different from the second alignment direction (Y2) because the other ends (B11) and (B21) are located on the same level, and the other ends (B22) and (B14) are located on different levels. In this embodiment, the first arrangement direction (Y1) is the row direction, and the second arrangement direction (Y2) is the column direction.

[0101] In the configuration of the first example (where the first spacing dimension is different from the second spacing dimension), the first alignment direction may be the same as or different from the second alignment direction. Also, in the configuration of the second example (where the first alignment direction is different from the second alignment direction), the first spacing dimension may be the same as or different from the second spacing dimension.

[0102] As described above, having different spacings at the other ends (B) corresponds to either the first example (where the first spacing dimension differs from the second spacing dimension) or the second example (where the first alignment direction differs from the second alignment direction). In other words, having different spacings at the other ends (B) means that the configuration shown in Figure 9 is not possible, nor is the configuration shown in Figure 10. The configuration shown in Figure 9 is one in which all combinations of two adjacent other ends (B) are connected in the step direction by the refrigerant passage (51). The configuration shown in Figure 10 is one in which all combinations of two adjacent other ends (B) are connected in the row direction by the refrigerant passage (51).

[0103] Furthermore, the refrigerant passage (61) formed in the rear plate structure (60) and the other end (B) of the heat transfer tube (42) connected to the rear plate structure (60) may have the same configuration as the refrigerant passage (51) formed in the front plate structure (50) and the other end (B) of the heat transfer tube (42) connected to the front plate structure (50) (a configuration in which the spacing of the other end (B) is different, i.e., a configuration corresponding to the first example or the second example above).

[0104] (7) Effects of the Embodiment As described above, the other end (B) of the heat transfer tube (42) is connected to the refrigerant passage (51, 61) of the plate structure (50, 60), and the distance between the first other end (B12, B11) and the second other end (B13, B21) is different from the distance between the third other end (B22) and the fourth other end (B33, B14) (the distance between the other ends (B) is different). As a result, by appropriately forming the refrigerant passage (51, 61), it is possible to connect not only adjacent other ends (B) but also non-adjacent other ends (B), thereby improving the degree of freedom in the connection destination (path) of the other ends (B).

[0105] (8) Modified Refrigerant Passage The indoor unit (30) described above may have the following modified configuration. The differences from the above embodiment will be described below.

[0106] As shown in Figure 11, the refrigerant passages (51, 61) of the plate structures (50, 60) may include a refrigerant passage (51f) that connects other ends (B11, B32) located at a distance of one or more stages in the heat exchange path. This improves the flexibility of path selection for other ends (B) of the heat transfer tube (42) that are located on the opposite side from the side to which the gas pipe (12a) or liquid pipe (13a) is connected, and is not limited to connecting adjacent other ends (B).

[0107] In the heat transfer tube (42), the connection section (70) (see Figure 5) located on the side to which the gas tube (12a) or liquid tube (13a) is connected does not need to have a configuration that connects two end sections (A) that are located at least one stage apart in the heat exchange path, by using a U-shaped tube (73) that connects two adjacent end sections (A). This simplifies the configuration of the connection section (70).

[0108] As shown in Figure 11, the refrigerant passages (51, 61) of the plate structure (50, 60) may include refrigerant passages (51g) that branch off and connect to three or more other ends (B31, B43, B44). This allows for greater flexibility in the path configuration of the other end (B) of the heat transfer tube (42), which is located on the opposite side from the side to which the gas pipe (12a) or liquid pipe (13a) is connected.

[0109] In the connection section (70) (see Figure 5), one end (A) of a single first heat transfer tube (42) and one end (A) of a single second heat transfer tube (42) are connected by a U-shaped pipe (73), so it is not necessary to have a configuration that branches the piping and connects three or more ends (A). This simplifies the configuration of the connection section (70).

[0110] As shown in Figure 11, the refrigerant passages (51,61) of the plate structure (50,60) may include refrigerant passages (51h,51,51i) that intersect each other when viewed in the alignment direction (Z) (see Figure 4). In the alignment direction (Z), the refrigerant passages (51h) and (51i) do not communicate with each other because the positions of their intersecting parts are different when viewed in the alignment direction (Z). As a result, the refrigerant passages (51h) and (51i) form independent passages. Consequently, the degree of freedom in routing the other end (B) of the heat transfer tube (42), which is located on the opposite side from the side to which the gas pipe (12a) or liquid pipe (13a) is connected, can be improved.

[0111] The connection section (70) (see Figure 5) does not necessarily have to have a configuration in which the first pipe connecting the first ends (A) and the second pipe connecting the second ends (A) intersect when viewed in the arrangement direction (Z). For example, it does not have to have a configuration in which two U-shaped pipes (73) are arranged in a cross pattern. This simplifies the configuration of the connection section (70).

[0112] As shown in Figure 12A, three or more end portions (A14, A24, A34, A44) connected to a gas pipe (12a) or liquid pipe (13a) via a branch pipe (71) may be adjacent to each other. In this case, the plate structures (50, 60) form a refrigerant passage (51) such that three or more end portions (A14, A24, A34, A44) connected to a gas pipe (12a) or liquid pipe (13a) are adjacent to each other. Three or more of the aforementioned end portions (A14, A24, A34, A44) being adjacent means that three or more of the aforementioned end portions (A14, A24, A34, A44) are arranged such that no other end portion (A) is located between them. Below, an example of the configuration of the refrigerant passage (51) in this case will be described. As shown in Figure 12A, in the heat transfer tube (42), the multiple ends (A) include end (A11) to end (A14), end (A21) to end (A24), end (A31) to end (A34), and end (A41) to end (A44). As shown in Figures 12A and 12B, the ends (A11, B11) are both ends of a single heat transfer tube (42). Each of the ends (A12, B12) to end (A14, B14), end (A21, B21) to end (A24, B24), end (A31, B31) to end (A34, B34), and end (A41, B41) to end (A44, B44) are also both ends of a different single heat transfer tube (42). Each of the ends (A12, A13), (A22, A23), (A32, A33), and (A42, A43) is connected by a U-shaped pipe (73). The ends (A14, A24, A34, A44) are arranged in a stepped direction and are adjacent to each other in that order. The ends (A14, A24, A34, A44) are connected to a gas pipe (12a) or liquid pipe (13a) via a connecting pipe (72) and a diversion pipe (71). Each of the other ends (B11, B12), other ends (B13, B14), other ends (B21, B22), other ends (B23, B24), other ends (B31, B32), other ends (B33, B34), other ends (B41, B42), and other ends (B43, B44) is connected by a refrigerant passage (51). This forms four passages.The first passage is connected in the following order: one end (A11), the other end (B11), the other end (B12), one end (A12), one end (A13), the other end (B13), the other end (B14), one end (A14), connecting pipe (72), flow divider (71), and gas pipe (12a) or liquid pipe (13a). The second passage starts from one end (A21) and is connected to the gas pipe (12a) or liquid pipe (13a). The third passage starts from one end (A31) and is connected to the gas pipe (12a) or liquid pipe (13a). The fourth passage starts from one end (A41) and is connected to the gas pipe (12a) or liquid pipe (13a) (see the arrows in Figures 12A and 12B for the specific connection order of each of the second to fourth passages). As described above, by connecting plate structures (50, 60) to the other end (B) of the heat transfer tube (42), a refrigerant passage (51) within the plate structure (50, 60) can be formed such that three or more ends (A14, A24, A34, A44) connected to the gas pipe (12a) or liquid pipe (13a) are adjacent to each other. This allows three or more different heat transfer tubes (42) (three or more ends (A14, A24, A34, A44)) to be arranged so that the supercooled or heated regions are adjacent to each other. As a result, the supercooled or heated regions can be concentrated, so the range affected by heat conduction from the supercooled or heated regions (the range in which the refrigerant flowing through the surrounding heat transfer tubes (42) is affected by heat conduction from the supercooled or heated regions) can be narrowed compared to when the supercooled or heated regions are dispersed. Therefore, it is possible to suppress the performance degradation of the indoor heat exchanger (40) due to heat conduction from the supercooled or heated regions.

[0113] Furthermore, the ends (A14, A24, A34, A44) may be arranged along the column direction and may be adjacent to each other in that order. In other words, three or more of the aforementioned ends (A14, A24, A34, A44) being adjacent includes not only three or more ends (A14, A24, A34, A44) being arranged along the row direction, but also three or more ends (A14, A24, A34, A44) being arranged along the column direction. Also, three or more of the aforementioned ends (A14, A24, A34, A44) being adjacent includes cases where some of the three or more ends (A14, A24, A34, A44) are arranged along the row direction and other parts are arranged along the column direction.

[0114] As shown in Figure 11, the refrigerant passages (51, 61) of the plate structures (50, 60) may include a refrigerant passage (51e). The refrigerant passage (51e) connects the other end (B14) of a single heat transfer tube (42), to which a gas pipe (12a) or liquid pipe (13a) is connected at one end (A), to a plurality of other ends (B21, B22) of the single heat transfer tube (42) other than the other end (B14). In this case, since the refrigerant passage (51e) forms a passage through which the refrigerant flows on the other end (B) side of the heat transfer tube (42), a flow divider (71) does not need to be provided at the connection part (70) (see Figure 8) located on the one end (A) side of the heat transfer tube (42). As a result, the configuration of the connection part (70) can be simplified.

[0115] As shown in Figures 3 and 13, the front heat exchange section (40A) includes a first front main heat exchange section (43a) and a second front main heat exchange section (43b) connected to the first front main heat exchange section (43a), and is bent at the point where the first front main heat exchange section (43a) and the second front main heat exchange section (43b) are connected. The refrigerant passages (51) of the plate structure (50) may include refrigerant passages (51j, 51k) connecting the other ends (B51, B54) of the heat transfer tubes (42) arranged in the first heat exchange section (43a) and the other ends (B52, B53) of the heat transfer tubes (42) arranged in the second heat exchange section (43b). In this case, the connection part (70) (see Figure 8) does not need to be provided with refrigerant piping connecting one end (A) of the heat transfer tube (42) located in the first heat exchange section (43a) and one end (A) of the heat transfer tube (42) located in the second heat exchange section (43b). As a result, the configuration of the connection part (70) can be simplified.

[0116] (9) Other Embodiments As shown in Figure 6, in the plate structure (50, 60), the number of stacked plate-shaped members may be five or less. Furthermore, each of the five or fewer plate-shaped members may have a thickness of 3 mm or less. This reduces the overall space occupied by the indoor heat exchanger (40) and improves the design flexibility of the indoor unit (30).

[0117] The plate structures (50, 60) may be joined to the multiple heat transfer tubes (42) by brazing. This allows the joint between the plate structures (50, 60) and the heat transfer tubes (42) to be sealed, reducing the risk of refrigerant leakage.

[0118] As shown in Figure 14, plate structures (81, 82) may be provided at the connection portion (70). One end (A) of a heat transfer tube (42) provided in the front heat exchange section (40A) is connected to plate structure (81). One end (A) of a heat transfer tube (42) provided in the rear heat exchange section (40B) is connected to plate structure (82). A second refrigerant passage is formed inside the plate structures (81, 82). The second refrigerant passage formed inside the plate structures (81, 82) is connected (communicates) with one end (A) of the heat transfer tube (42). The ends (A) of the heat transfer tubes (42) are connected to each other via the second refrigerant passage. The plate structures (81, 82) consist of multiple plate-shaped components. This is a plate laminate formed by stacking components. The plate structure (81, 82) is a thick plate-like component formed by stacking multiple plate-shaped components, and a second refrigerant passage is formed inside using a structure similar to that of the plate structure (50, 60). The first internal piping (38) and the liquid pipe (13a) are connected to the second refrigerant passage. The second internal piping (39) and the gas pipe (12a) are connected to the second refrigerant passage. The second refrigerant passage may also function as a flow divider (71). The plate structure (81, 82) is an example of the second plate structure.

[0119] The front plate structure (50) may be composed of a single plate. In the modified front plate structure (50), a coolant passage is formed inside, similar to the embodiment described above. The modified front plate structure (50) is manufactured by sintering metal powder using a 3D printer. The rear plate structure (60) and the plate structures (81, 82) may also each be composed of a single plate.

[0120] The indoor heat exchanger (40) does not have to be of the fin and tube type; for example, it may be of the corrugated type, in which corrugated fins are arranged between adjacent heat transfer tubes.

[0121] As shown in Figure 15, the heat transfer tube (42) may be a flattened multi-hole tube. The heat transfer tube (42), which is a flattened multi-hole tube, is made of aluminum or an aluminum alloy, for example, and has a flattened surface (42a) that serves as the heat transfer surface and a number of small internal flow channels (42b) through which the refrigerant flows. Multiple fin grooves (41a) are formed in the fin (41). The heat transfer tube (42) is attached to the fin (41) by inserting it into the fin grooves (41a).

[0122] The indoor heat exchanger (40) may not have a front heat exchange section (40A) and a rear heat exchange section (40B), but may have a single heat exchange section. In this case, the first internal piping (38), the second internal piping (39), and the indoor expansion valve (37) are omitted.

[0123] The heat transfer tubes (42) of the heat exchanger body (4X) may be made of a copper alloy instead of an aluminum alloy. When the heat transfer tubes (42) are made of a copper alloy, it is preferable that the plate structures (50, 60) are also made of a copper alloy.

[0124] Multiple heat transfer tubes (42) may be arranged in parallel such that the direction of arrangement of heat transfer tubes (42) arranged in the tiered direction and the direction of arrangement of heat transfer tubes (42) arranged in the row direction are perpendicular to each other (see Figure 16).

[0125] In this embodiment, all of the multiple other ends (B) are connected to the refrigerant passages (51, 61) of the plate structure (50, 60). However, not all of the multiple other ends (B) are necessarily connected to the refrigerant passages (51, 61) of the plate structure (50, 60). In this case, for example, one group of other ends (B) (first group of other ends) is connected to the refrigerant passages (51, 61) of the plate structure (50, 60), and the remaining group of other ends (B) (second group of other ends) is connected to refrigerant piping. That is, in the multiple other ends (B), the other ends (B) included in the first group of other ends are connected to each other via the refrigerant passages (51, 61) of the plate structure (50, 60), and the other ends (B) included in the second group of other ends are connected to each other via refrigerant piping.

[0126] In this embodiment, the front plate structure (50) is separate from the rear plate structure (60). However, the front plate structure (50) may be integrated with the rear plate structure (60).

[0127] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the embodiments, modifications, and other embodiments described above may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0128] The designations "first," "second," "third," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms.

[0129] As described above, this disclosure is useful for indoor units of air conditioning systems and air conditioning systems.

[0130] 11 Refrigerant circuit 12a Gas pipe 13a Liquid pipe 22 Outdoor heat exchanger 40 Indoor heat exchanger 40A Front heat exchange section 40B Rear heat exchange section 41 Fin 42 Heat transfer tube 50 Front plate structure 51 Refrigerant passage 60 Rear plate structure 61 Refrigerant passage A One end B Other end Z Arrangement direction Z1 One direction Z2 Other direction

Claims

1. An indoor heat exchanger (40) including a plurality of fins (41) and a plurality of heat transfer tubes (42) attached to the plurality of fins (41), and a first plate structure (50, 60) in which a first refrigerant passage (51, 61) is formed inside, wherein each of the plurality of heat transfer tubes (42) includes one end (A) located on one side (Z1) of the arrangement direction (Z) of the plurality of fins (41) and another end (B) located on the other side (Z2) of the arrangement direction (Z), at least one of a gas pipe (12a) and a liquid pipe (13a) connecting the indoor heat exchanger (40) and the outdoor heat exchanger (22) is connected to the one end (A), and the first refrigerant passage (51, 61) of the first plate structure (50, 60) is connected to the other end (B). The first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a first passage connected to a first other end and a second other end of a plurality of other ends (B), and a second passage connected to a third other end and a fourth other end of a plurality of other ends (B), wherein the distance between the first other end and the second other end is different from the distance between the third other end and the fourth other end, in the indoor unit of an air conditioning system.

2. The indoor unit of the air conditioning system according to claim 1, wherein the distance between the first other end and the second other end is different from the distance between the third other end and the fourth other end, which indicates that the distance dimension (D1) between the first other end (B12) and the second other end (B13) is different from the distance dimension (D2) between the third other end (B22) and the fourth other end (B33).

3. The indoor unit of an air conditioning system according to claim 1 or claim 2, wherein the distance between the first other end and the second other end is different from the distance between the third other end and the fourth other end, which indicates that the alignment direction (Y1) of the first other end (B11) and the second other end (B21) is different from the alignment direction (Y2) of the third other end (B22) and the fourth other end (B14).

4. An indoor unit of an air conditioning system according to any one of claims 1 to 3, comprising a diversion pipe (71) connecting the gas pipe (12a) or the liquid pipe (13a) to three or more of the one ends (A14, A24, A34, A44), wherein the three or more one ends (A14, A24, A34, A44) are adjacent to each other.

5. The indoor unit of an air conditioning system according to any one of claims 1 to 4, wherein the first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a third passage (51e) that connects the other end (B14) of a single heat transfer tube (42) to which the gas pipe (12a) or the liquid pipe (13a) is connected at one end (A), and a plurality of other ends (B21, B22) of the single heat transfer tube (42) other than the other end (B14).

6. The indoor unit of an air conditioning system according to any one of claims 1 to 5, wherein the indoor heat exchanger (40) includes a first heat exchange section (43a) and a second heat exchange section (43b) connected to the first heat exchange section (43a), and is bent at the point where the first heat exchange section (43a) and the second heat exchange section (43b) are connected, and the first refrigerant passage (51) of the first plate structure (50) includes a fourth passage (51j, 51k) connecting the other end (B51, B54) of the heat transfer tube (42) arranged in the first heat exchange section (43a) and the other end (B52, B53) of the heat transfer tube (42) arranged in the second heat exchange section (43b).

7. An indoor unit of an air conditioning system according to claim 6, which does not include a refrigerant piping connecting one end (A) of the heat transfer tube (42) arranged in the first heat exchange section (43a) and one end (A) of the heat transfer tube (42) arranged in the second heat exchange section (43b).

8. The indoor unit of an air conditioning system according to any one of claims 1 to 7, wherein the first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a fifth passage (51f) that connects the other ends (B11, B32) located at one or more stages apart in the heat exchange path.

9. An indoor unit of an air conditioning system according to claim 8, comprising a refrigerant pipe (48) connecting the one ends (A) of the heat transfer tubes (42), wherein the refrigerant pipe (48) does not connect the one ends (A) located at one or more stages apart in the heat exchange path.

10. The indoor unit of an air conditioning system according to any one of claims 1 to 9, wherein the first refrigerant passage (51, 61) of the first plate structure (50, 60) includes a sixth passage (51g) that branches off and is connected to three or more of the other ends (B31, B43, B44).

11. An indoor unit of an air conditioning system according to any one of claims 1 to 10, comprising a refrigerant pipe (73) connecting the one ends (A) of the heat transfer tubes (42), wherein the refrigerant pipe (73) connects the one end (A) of a single first heat transfer tube (42) to the one end (A) of a single second heat transfer tube (42).

12. The indoor unit of an air conditioning system according to any one of claims 1 to 11, wherein the first refrigerant passages (51, 61) of the first plate structure (50, 60) include seventh refrigerant passages (51h, 51, 51i) that intersect each other when viewed in the arrangement direction (Z).

13. An indoor unit of an air conditioning system according to any one of claims 1 to 12, comprising a first pipe (73) connecting the first end (A) of the unit and a second pipe (73) connecting the second end (A) of the unit, wherein the first pipe (73) and the second pipe (73) do not intersect when viewed in the arrangement direction (Z).

14. An indoor unit of an air conditioning system according to any one of claims 1 to 13, comprising a second plate structure (81, 82) having a second refrigerant passage formed inside, wherein the second refrigerant passage of the second plate structure (81, 82) is connected to one end (A).

15. The indoor unit of an air conditioning system according to any one of claims 1 to 14, wherein the first plate structure (50, 60) is brazed to the plurality of heat transfer tubes (42).

16. The indoor unit of an air conditioning system according to any one of claims 1 to 15, wherein the heat transfer tube (42) is a flattened multi-hole tube.

17. The indoor unit of an air conditioning system according to any one of claims 1 to 16, wherein the first plate structure (50, 60) includes five or fewer stacked plate-shaped members.

18. The indoor unit of the air conditioning system according to claim 17, wherein each of the five or fewer plate-shaped members has a thickness of 3 mm or less.

19. An indoor unit of an air conditioning system according to any one of claims 1 to 18, comprising a tube sheet (49) supporting the other-direction side (Z2) of the plurality of heat transfer tubes (42), wherein the distance between the tube sheet (49) and the first plate structure (50, 60) is 30 mm or less.

20. An air conditioning system comprising an indoor unit according to any one of claims 1 to 19.

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