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

Abstract

To improve insertion performance of a connection pipe into a heat transfer pipe in a heat exchanger having a plate structure in which a flow passage communicating a plurality of heat transfer pipes is formed.SOLUTION: A heat exchanger (40) includes a heat exchange part (40A) having a fin (41) and a plurality of heat transfer pipes (42), and a plate structure (50) arranged to be overlapped with the heat exchange part (40A) in an axial direction of the heat transfer pipes (42) and having a refrigerant flow passage (51) formed therein so as to communicate the heat transfer pipes (42) with each other. The plate structure (50) includes a body (52) having a refrigerant flow passage (51) formed therein, and a plurality of connection pipes (53) arranged on a surface on the heat exchange part (40A) side of the body (52) and connecting the plurality of heat transfer pipes (42) and the refrigerant flow passage (51), and the body (52) and the connection pipes (53) are integrally formed.SELECTED DRAWING: Figure 10

Description

[Technical field]

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

[0002] Patent Document 1 discloses a refrigerant flow distributor used in a heat exchanger. The refrigerant flow distributor described in Patent Document 1 is a plate structure in which an underplate, an overplate, and a cover are stacked. The overplate has a plurality of burring holes. A connecting pipe separate from the overplate is connected to the burring holes. The connecting pipe connects a flow path in the refrigerant flow distributor to a heat transfer tube of a heat exchanger. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-220914 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a separate connecting pipe is connected to a plate, the axis of the hole in the plate and the axis of the connecting pipe may be misaligned, or the connecting pipe may be inclined obliquely relative to the plate, which may cause a pitch misalignment between the connecting pipe and the heat transfer pipe. In particular, when the hole in the plate is a burring hole as in Patent Document 1, the axis of the burring hole may be inclined obliquely rather than perpendicularly to the plate. If the axis of the burring hole is inclined obliquely relative to the plate, the connecting pipe connected to the burring hole is likely to be inclined obliquely, which may cause a pitch misalignment between the connecting pipe and the heat transfer pipe. If a pitch misalignment occurs between the connecting pipe and the heat transfer pipe, the insertability of the connecting pipe into the heat transfer pipe may be deteriorated.

[0005] An object of the present disclosure is to improve the ease of inserting a connecting tube into a heat transfer tube in a heat exchanger having a plate structure in which a flow passage is formed that connects a plurality of heat transfer tubes. [Means for solving the problem]

[0006] The first aspect is directed to a heat exchanger. The heat exchanger includes a heat exchange section (40A) having fins (41) and a plurality of heat transfer tubes (42), and a plate structure (50) arranged to overlap the heat exchange section (40A) in the axial direction of the heat transfer tubes (42) and forming a refrigerant flow path (51) therein that connects the heat transfer tubes (42). The plate structure (50) has a first surface (52c) that is a surface on the heat exchange section (40A) side in the axial direction of the heat transfer tubes (42) and a second surface (52d) that is a surface on the opposite side to the first surface (52c) in the axial direction, a main body (52) having the refrigerant flow path (51) therein, and a plurality of connection pipes (53) arranged on the first surface (52c) and connecting the plurality of heat transfer tubes (42) and the refrigerant flow path (51). The main body (52) and the connecting pipe (53) are integrally formed.

[0007] In the first aspect, by integrally molding the main body portion (52) and the connecting pipe (53), it is possible to prevent the axis of the connecting pipe (53) from shifting or from tilting obliquely with respect to the first surface (52c) of the main body portion (52). This prevents pitch deviation between the connecting pipe (53) and the heat transfer pipe (42), improving the ease of inserting the connecting pipe (53) into the heat transfer pipe (42).

[0008] In the second aspect, in the first aspect, the fin (41) has a first portion (41a) having a longitudinal direction that is a first direction (D1) when viewed in the axial direction of the heat transfer tube (42), and a second portion (41b) having a longitudinal direction that is a second direction (D2) intersecting the first direction (D1) when viewed in the axial direction, the multiple heat transfer tubes (42) are arranged in both the first portion (41a) and the second portion (41b), the main body portion (52) has a first overlapping portion (52a) overlapping with the first portion (41a) when viewed in the axial direction, and a second overlapping portion (52b) overlapping with the second portion (41b) and integral with the first overlapping portion (52a) when viewed in the axial direction, and the multiple connecting pipes (53) are arranged in both the first overlapping portion (52a) and the second overlapping portion (52b).

[0009] In the second embodiment, since the heat transfer tubes (42) are disposed in both the first portion (41a) and the second portion (41b) and the connecting tubes (53) are disposed in both the first overlapping portion (52a) and the second overlapping portion (52b) as described above, if the connecting tubes (53) were separate from the main body portion (52), a pitch misalignment would easily occur between the heat transfer tubes (42) and the connecting tubes (53). By integrally molding the main body portion (52) and the connecting tubes (53) together, even if the arrangement of the heat transfer tubes (42) is complex, a pitch misalignment between the connecting tubes (53) and the heat transfer tubes (42) is suppressed, and therefore the connecting tubes (53) can be easily inserted into the heat transfer tubes (42).

[0010] In a third aspect, in the first or second aspect, the amount of protrusion of the connecting pipe (53) from the first surface (52c) is 5 mm or more.

[0011] If the connecting pipe (53) has a certain length as in the third embodiment, and if the connecting pipe (53) is separate from the main body (52), the axis of the connecting pipe (53) is likely to tilt obliquely with respect to the first surface. By integrally molding the main body (52) and the connecting pipe (53), the axis of the connecting pipe (53) can be prevented from tilting, and the pitch deviation between the connecting pipe (53) and the heat transfer pipe (42) can be prevented. This improves the ease of insertion of the connecting pipe (53) into the heat transfer pipe (42).

[0012] In a fourth aspect, in any one of the first to third aspects, the connecting pipe (53) includes connecting pipes (53a, 53b) having different outer diameters.

[0013] If the connecting pipes (53a, 53b) have different outer diameters as in the fourth aspect, it would be difficult to align the connecting pipes (53a, 53b) having different outer diameters if the connecting pipes (53a, 53b) are separate from the main body (52). If the main body (52) and the connecting pipes (53a, 53b) are integrally molded, it becomes easy to align the connecting pipes (53a, 53b). Therefore, even if the connecting pipes (53a, 53b) have different outer diameters, it is possible to suppress pitch deviation between the connecting pipes (53a, 53b) and the heat transfer tube (42).

[0014] In a fifth aspect, in any one of the first to fourth aspects, the connecting pipe (53) is made of aluminum, and the wall thickness of the connecting pipe (53) is 0.4 mm or more.

[0015] In the fifth aspect, the strength of the connecting pipe (53) can be improved.

[0016] In a sixth aspect, in any one of the first to fourth aspects, the connecting pipe (53) is made of copper, and the wall thickness of the connecting pipe (53) is 0.2 mm or more.

[0017] In the sixth aspect, the strength of the connecting pipe (53) can be improved.

[0018] In a seventh aspect, in any one of the first to sixth aspects, the heat transfer tube (42) is inserted around the connecting tube (53).

[0019] In the seventh aspect, since the heat transfer tube (42) is inserted onto the connecting tube (53), the inner diameter of the heat transfer tube (42) is larger than the outer diameter of the connecting tube (53) at the connection portion between the heat transfer tube (42) and the connecting tube (53). This improves ease of insertion of the connecting tube (53) into the heat transfer tube (42).

[0020] In an eighth aspect, based on the seventh aspect, a connection portion of the heat transfer tube (42) with the connecting tube (53) has a flared portion (42a).

[0021] In the eighth aspect, the heat transfer tube (42) has the flare portion (42a), which makes it easier to insert the connecting tube (53) into the heat transfer tube (42). This improves the ease of inserting the connecting tube (53) into the heat transfer tube (42).

[0022] In a ninth aspect, in any one of the first to eighth aspects, the main body (52) is a plate stack in which a plurality of plates (521, 522, 523, 524, 525) are stacked, and the plate (521) constituting the first surface (52c) and the connecting pipe (53) are integrally formed by casting.

[0023] In the ninth aspect, the airtightness between the connecting pipe (53) and the plate (521) can be improved as compared to when the connecting pipe (53) and the plate (521) are separate bodies.

[0024] In a tenth aspect, in any one of the first to eighth aspects, the main body (52) and the connecting pipe (53) are integrally formed by sintering.

[0025] In the tenth aspect, even if the arrangement of the connecting pipes (53) is complicated, the plate structure can be manufactured with high precision.

[0026] In an eleventh aspect, the heat exchange section (40A, 40B) includes a first heat exchange section (40A) and a second heat exchange section (40B) arranged in a direction perpendicular to the axial direction of the heat transfer tube (42), the plate structure (50, 60) includes a first plate structure (50) connected to the heat transfer tube (42) of the first heat exchange section (40A) and a second plate structure (60) connected to the heat transfer tube (42) of the second heat exchange section (40B), and a refrigerant piping (38) connecting a refrigerant flow path (51) of the first plate structure (50) and a refrigerant flow path (61) of the second plate structure (60) is connected to the second surface (52d) of the first plate structure (50) and the second surface (62b) of the second plate structure (60).

[0027] In the eleventh aspect, the refrigerant pipes (38) are connected to the second surfaces (52d, 62b), so that the connection between the main body (52, 62) and the refrigerant pipes (38) does not affect the arrangement of the connecting pipes (53, 63). This makes it possible to effectively reduce pitch deviation between the connecting pipes (53, 63) and the heat transfer pipes (42).

[0028] A twelfth aspect is a refrigeration cycle apparatus including a refrigerant circuit (11) to which the heat exchanger (40) according to any one of the first to eleventh aspects is connected.

[0029] A thirteenth aspect is an air conditioning indoor unit including the heat exchanger (40) according to any one of the first to eleventh aspects, and a casing (31) that houses the heat exchanger (40). [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a piping diagram of an air conditioner according to an embodiment. [Diagram 2] FIG. 2 is a front view of the air conditioning indoor unit. [Diagram 3] FIG. 3 is a cross-sectional view of the air conditioning indoor unit taken along line II-II. [Figure 4] FIG. 4 is a front view showing the internal structure of the air conditioning indoor unit. [Diagram 5]FIG. 5 is an enlarged perspective view showing a main part of the indoor heat exchanger. [Figure 6] FIG. 6 shows the plate stack as seen from the left side. [Figure 7] FIG. 7 is a cross-sectional view illustrating a coolant flow path of a plate stack. [Figure 8] FIG. 8 is a partial perspective view of the front plate stack. [Figure 9] FIG. 9 is a right-side view of the front plate stack. [Figure 10] FIG. 10 is a cross-sectional view taken along line IX-IX in FIG. [Figure 11] FIG. 11 is a right-side view of the rear plate stack. [Figure 12] FIG. 12 is a partial perspective view of a front plate structure according to the second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical idea of ​​the present disclosure. Since each drawing is intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0032] (1) Overall configuration of air conditioning system This embodiment is an air conditioner including a heat exchanger unit (10). The air conditioner (10) adjusts the temperature of air in an indoor space (I), which is a target space.

[0033] 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.

[0034] 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.

[0035] 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 switching valve (24), and an outdoor fan (25) housed in the outdoor casing (20a).

[0036] The compressor (21) is a rotary compressor such as a swing piston type, rotary type, or scroll type. The outdoor heat exchanger (22) exchanges heat between the refrigerant and outdoor air. The outdoor heat exchanger (22) is 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 (a state shown by a solid line in FIG. 1) and a second state (a state shown by a dashed line in FIG. 1). In the first state, the four-way switching valve (24) communicates between the discharge portion of the compressor (21) and the gas end of the outdoor heat exchanger (22) and also communicates between the suction portion of the compressor (21) and the first connection pipe (12). The four-way switching valve (24) in the second state communicates the discharge portion of the compressor (21) with the first connection pipe (12) and also communicates the suction portion of the compressor (21) with the gas end of the outdoor heat exchanger (22). The outdoor fan (25) transports the air flowing through the outdoor heat exchanger (22). The outdoor fan (25) is a propeller fan.

[0037] The indoor unit (30) includes a casing (31), and an indoor heat exchanger (40), an indoor fan (32), and an indoor expansion valve (37) housed in the casing (31).

[0038] (2) Air conditioning indoor unit The indoor unit (30), which is an indoor air conditioner, will be described in detail with reference to Figs. 2 to 4. The indoor unit (30) of this embodiment is a wall-mounted type provided on a wall of the indoor space (I). Note that the terms "upper," "lower," "right," "left," "front," and "rear" described below correspond to the directions of the arrows shown in Figs. 2 and 3, and the left-right direction is based on the case where the indoor casing (31) is viewed from the front.

[0039] (2-1) Casing 2 and 3, the casing (31) is formed in a horizontally long box shape and has a front plate (31a), a rear plate (31b), an upper plate (31c), a lower plate (31d), a first side plate (31e), and a second side plate (31f).

[0040] The front plate (31a) is formed on the front side of the casing (31) and constitutes the front surface of the casing (31). The rear plate (31b) is formed on the rear side of the casing (31) and constitutes the rear surface of the casing (31). The upper plate (31c) is formed on the upper side of the casing (31) and constitutes the upper surface of the casing (31). The lower plate (31d) is formed on the lower side of the casing (31) and constitutes the lower surface of the casing (31). The first side plate (31e) is formed on the right side of the casing (31) and constitutes the right surface of the casing (31). The second side plate (31f) is formed on the left side of the casing (31) and constitutes the left surface of the casing (31).

[0041] An intake port (33) is formed in the upper plate (31c), and an exhaust port (34) is formed in the lower plate (31d). An air passage (P) is formed inside the casing (31) from the intake port (33) to the exhaust port (34). The intake port (33) extends in the longitudinal direction of the casing (31). The intake port (33) is an opening for taking air from the indoor space (I) into the air passage (P). An exhaust port (34) is formed in the lower plate (31d). The exhaust port (34) extends in the longitudinal direction of the casing (31). The exhaust port (34) is an opening for blowing air from the air passage (P) into the indoor space (I).

[0042] (2-2) Filter The indoor unit (30) includes a filter (35). The filter (35) is disposed on the rear side of the suction port (33) and upstream of the indoor heat exchanger (40). The filter (35) collects dust in the air sent from the suction port (33) to the indoor heat exchanger (40). The indoor unit (30) may include a dust removal mechanism that removes the dust collected by the filter (35).

[0043] (2-3) Heat exchanger unit The heat exchanger unit (U) includes one indoor heat exchanger (40) and one indoor expansion valve (37). The indoor heat exchanger (40) includes one heat exchanger body (B) and two plate stacks (50, 60). The heat exchanger body (B) of the indoor heat exchanger (40) is disposed so as to cross the air passage (P). The air passage (P) is divided into an upstream side and a downstream side of the heat exchanger body (B).

[0044] (2-4) Indoor fan The indoor fan (32) is disposed in the air passage (P). The indoor fan (32) is disposed in the air passage (P) downstream of the indoor heat exchanger (40). The indoor fan (32) is a crossflow fan. The indoor fan (32) has a fan rotor that extends in the longitudinal direction of the casing (31).

[0045] (2-5) Flap The indoor unit (30) has a flap (36) that adjusts the direction of air blown out of the air outlet (34). The flap (36) adjusts the air direction in the vertical direction. The indoor unit (30) may have a plurality of flaps (36). The flap (36) may adjust the air direction in the horizontal direction.

[0046] (3) Heat exchanger unit As described above, the heat exchanger unit (U) includes the indoor heat exchanger (40), the indoor expansion valve (37), the gas relay pipe (12a), and the liquid relay pipe (13a).

[0047] (3-1) Indoor heat exchanger The indoor heat exchanger (40) shown in Figures 3 to 5 includes a heat exchanger body (B) and a plate stack (50, 60) connected to the heat exchanger body (B). The indoor heat exchanger (40) is a fin-and-tube heat exchanger having fins (41) and heat transfer tubes (42). The indoor heat exchanger (40) exchanges heat between air and a refrigerant.

[0048] The heat exchanger body (B) has a plurality of fins (41) arranged in the longitudinal direction of the casing (31) and a plurality of heat transfer tubes (42) extending in the arrangement direction of the fins (41). The plate stacks (50, 60) have therein refrigerant flow paths (51, 61) that communicate with the heat transfer tubes (42).

[0049] The arrangement direction of the fins (41) corresponds to the longitudinal direction (here, the left-right direction) of the casing (31). The fins (41) are rectangular plate-shaped having long sides and short sides. The thickness direction of the fins (41) corresponds to the arrangement direction of the fins (41). The multiple fins (41) are arranged at predetermined intervals in the thickness direction. This interval defines an air flow path. The material of the fins (41) is an aluminum alloy.

[0050] The heat transfer tubes (42) are straight tubes. The material of the heat transfer tubes (42) is an aluminum alloy. A refrigerant flow path is formed inside the heat transfer tubes (42). The heat transfer tubes (42) extend parallel to one another and penetrate the fins (41). One end of the heat transfer tube (42), which is a right end, protrudes to the right of the fin (41). One end of the heat transfer tube is connected to the plate stack (50, 60). Of the other ends of the heat transfer tubes (42), which are left ends, the left ends of two adjacent heat transfer tubes (42) are connected to each other by a U-shaped tube (48). The two adjacent heat transfer tubes (42) and the U-shaped tube (48) connecting them are formed integrally and seamlessly.

[0051] The indoor heat exchanger (40) of this embodiment 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 toward the front side of the casing (31), and the rear heat exchange section (40B) is located toward the rear side 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 up-down direction and the axial direction of the heat transfer tube (42), i.e., in the front-rear direction, with the indoor fan (32) between them.

[0052] The front heat exchange section (40A) includes a front main heat exchange section (43), a first auxiliary heat exchange section (44), and a second auxiliary heat exchange section (45).

[0053] The front main heat exchange section (43) is disposed closer to the indoor fan (32) in the front heat exchange section (40A). The front main heat exchange section (43) has an outer shape formed in a V-shape when viewed from the longitudinal direction of the heat transfer tube (42). The tip of the V-shape faces the front side. The fins (41) constituting the front main heat exchange section (43) have a first portion (41a) whose longitudinal direction is a first direction (D1) and a second portion (41b) whose longitudinal direction is a second direction (D2) perpendicular to the first direction (D1) when viewed from the longitudinal direction of the heat transfer tube (42). The first direction (D1) is a direction that extends obliquely upward toward the rear side. The second direction (D2) is a direction that extends obliquely downward toward the rear side. The angle between the first direction (D1) and the second direction (D2) is approximately 90° to 110°. The first portion (41a) and the second portion (41b) may be integrally formed or may be separate.

[0054] The front main heat exchange section (43) is composed of a first front main heat exchange section (43a) including a first portion (41a) of the fin (41) and a second front main heat exchange section (43b) including a second portion (41b) of the fin (41). The first front main heat exchange section (43a) is located at an upper portion of the front main heat exchange section (43), and the second front main heat exchange section (43b) is located at a lower portion of the front main heat exchange section (43). The lower end of the first front main heat exchange section (43a), i.e., the lower short side of the fin (41), contacts the long side of the fin (41) of the second front main heat exchange section (43b) (strictly speaking, the upper end portion of the long side of the fin (41)).

[0055] 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 lengths of the long sides and the short sides of the fins (41) of the first auxiliary heat exchange section (44) are shorter than the lengths of the long sides and the short sides of the first portions (41a) of the fins (41). The number of heat transfer tubes (42) in the first auxiliary heat exchange section (44) in the direction along the long sides (hereinafter referred to as the number of stages) is smaller than the number of stages of the heat transfer tubes (42) of the first front main heat exchange section (43a). The number of heat transfer tubes (42) in the first auxiliary heat exchange section (44) in the direction along the short sides (hereinafter referred to as the number of rows) is smaller than the number of rows of the heat transfer tubes (42) of the first front main heat exchange section (43a).

[0056] 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 lengths of the long sides and the short sides of the fins (41) of the second auxiliary heat exchange section (45) are shorter than the lengths of the long sides and the short sides of the second portions (41b) of the fins (41). The number of stages and rows of the heat transfer tubes (42) of the second auxiliary heat exchange section (45) is smaller than the number of stages and rows of the heat transfer tubes (42) of the second front main heat exchange section (43b).

[0057] The rear heat exchange section (40B) has a rear main heat exchange section (46) and a third auxiliary heat exchange section (47). The rear main heat exchange section (46) is disposed 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 lengths of the long and short sides of the fins (41) of the third auxiliary heat exchange section (47) are shorter than the lengths of the long and short sides of the fins (41) of the rear main heat exchange section (46). The number of stages and rows of the heat transfer tubes (42) of the third auxiliary heat exchange section (47) is smaller than the number of stages and rows of the heat transfer tubes (42) of the rear main heat exchange section (46).

[0058] As shown in Fig. 10, one end of the heat transfer tube (42) has a flare portion (42a) that is flared. The flare portion (42a) has an expanded diameter portion (42b) that expands in diameter toward the right, and a cylindrical portion (42c) that extends rightward with a constant diameter from the right end of the expanded diameter portion (42b). As will be described in detail later, the flare portion (42a) is a portion that is connected to the connecting pipes (53, 63) of the plate stacks (50, 60).

[0059] The plate stack (50, 60) is disposed on the right side of the rightmost fin (41) in parallel to the fin (41). The plate stack (50, 60) is connected to one end of the heat transfer tube (42). As shown in FIG. 5, the plate stack (50, 60) includes a front plate stack (50) connected to the heat transfer tube (42) of the front heat exchange section (40A) and a rear plate stack (60) connected to the heat transfer tube (42) of the rear heat exchange section (40B). The front plate stack (50) is disposed so as to overlap the front heat exchange section (40A) in the axial direction of the heat transfer tube (42). The rear plate stack (60) is disposed so as to overlap the rear heat exchange section (40B) in the axial direction of the heat transfer tube (42). The front plate stack (50) and the rear plate stack (60) will be described in detail later.

[0060] (3-2) Indoor expansion valve, gas relay pipe, liquid relay pipe The indoor expansion valve (37) is an electronic expansion valve with a variable opening degree. The indoor expansion valve (37) is disposed on the right side of the plate stack (50, 60). The indoor expansion valve (37) is connected to the front plate stack (50) via a first internal pipe (38) and is connected to the rear plate stack (60) via a second internal pipe (39). The first internal pipe (38) and the second internal pipe (39) are an example of refrigerant pipes that connect the refrigerant flow path (51) of the front plate stack (50) and the refrigerant flow path (61) of the rear plate stack (60).

[0061] One end of the gas relay pipe (12a) is connected to the rear plate assembly (60). The other end of the gas relay pipe (12a) is connected to the first connection pipe (12) via a joint. One end of the liquid relay pipe (13a) is connected to the front plate assembly (50). The other end of the liquid relay pipe (13a) is connected to the second connection pipe (13) via a joint.

[0062] (4) Plate stack The plate stack (50, 60) will be described in detail with reference to FIGS.

[0063] (4-1) Front plate assembly The front plate stack (50) includes a front main body portion (52) having a refrigerant flow path (51) therein, a plurality of front connecting pipes (53) connecting the plurality of heat transfer tubes (42) of the front heat exchange portion (40A) to the refrigerant flow path (51), a front relay portion (54) to which the first internal piping (38) is connected, and a liquid end portion (55) communicating with the second connection piping (13) via the liquid relay pipe (13a).

[0064] As shown in Fig. 5 and Fig. 8, the front main body portion (52) is a thick plate-like member formed by stacking five front plates. The stacking direction of the front plates is the same as the axial direction of the heat transfer tubes (42). In the front plate stack (50), a first front plate (521), a second front plate (522), a third front plate (523), a fourth front plate (524), and a fifth front plate (525) 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). The five front plates are flat plate-like members having the same outer edge shape. Each front plate is made of the same material as the heat transfer tube (42) and the front connecting tube (53). In this embodiment, the material of each front plate is an aluminum alloy. The first front plate (521) and the fifth front plate (525) have a thickness of 1.5 mm. The second front plate (522), the third front plate (523), and the fourth front plate (524) have a thickness of 3.0 mm. The front plates are joined to each other by furnace brazing. Note that the number of front plates is just an example, and the number of front plates may be four or less, or six or more. Hereinafter, when there is no need to distinguish between the front plates, they will simply be referred to as front plates.

[0065] As shown in FIG. 6, the front main body portion (52) has a first overlapping portion (52a) overlapping with the first portion (41a) of the fin (41) when viewed in the axial direction of the heat transfer tube (42). The front main body portion (52) has a second overlapping portion (52b) overlapping with the second portion (41b) of the fin (41) when viewed in the axial direction of the heat transfer tube (42). The first overlapping portion (52a) extends along the first direction (D1), and the second overlapping portion (52b) extends along the second direction (D2). The first overlapping portion (52a) and the second overlapping portion (52b) are integral with each other. More specifically, the first overlapping portion (52a) and the second overlapping portion (52b) are formed by stacking the same front plates.

[0066] The front main body portion (52) has a first left side surface (52c) which is a surface on the front heat exchanger portion (40A) side (here, the left side) in the axial direction of the heat transfer tube (42), a first right side surface (52d) which is a surface opposite to the first left side surface (52c) in the axial direction, and a first peripheral surface (52e) which is a peripheral surface extending between the first left side surface (52c) and the first right side surface (52d). The first left side surface (52c) is a surface of the first front plate (521) on the front heat exchanger portion (40A) side. The first right side surface (52d) is a surface of the fifth front plate (525) opposite to the fourth front plate (524). The first peripheral surface (52e) is a surface formed by the side surfaces of the front plates (521, 522, 523, 524, 525). The first left side surface (52c) corresponds to a first surface, and the first right side surface (52d) corresponds to a second surface.

[0067] The front connecting pipe (53) is a circular pipe. The material of the front connecting pipe (53) is an aluminum alloy. As shown in Fig. 9, the front connecting pipes (53) are disposed in both the first overlapping portion (52a) and the second overlapping portion (52b) of the front main body portion (52). The front connecting pipes (53) are provided on the first front plate (521) and disposed on the first left side surface (52c) of the front main body portion (52). The front connecting pipes (53) are arranged in a manner corresponding to the arrangement of the heat transfer tubes (42) of the front heat exchange portion (40A).

[0068] The front connecting pipes (53) include a front main connecting pipe (53a) and a front auxiliary connecting pipe (53b). The front main connecting pipe (53a) is connected to the heat transfer tube (42) of the front main heat exchange section (43). The front auxiliary connecting pipe (53b) is connected to the heat transfer tube (42) of the first auxiliary heat exchange section (44) and the heat transfer tube (42) of the second auxiliary heat exchange section (45). The front main connecting pipe (53a) and the front auxiliary connecting pipe (53b) have different outer diameters. Specifically, the front auxiliary connecting pipe (53b) has a larger diameter than the front main connecting pipe (53a). The front main connecting pipe (53a) has an outer diameter of, for example, 5 mm. The front auxiliary connecting pipe (53b) has an outer diameter of, for example, 7 mm. In the following description, when there is no need to distinguish between the front main connecting pipe (53a) and the front auxiliary connecting pipe (53b), they will simply be referred to as the front connecting pipe (53).

[0069] The amount of protrusion of the front connecting pipe (53) from the first left side surface (52c) is set so that heat generated when the front connecting pipe (53) and the heat transfer pipe (42) are connected by brazing does not melt the brazing material connecting the plates. The amount of protrusion of the front connecting pipe (53) from the first left side surface (52c) is the same as or longer than the flare portion (42a) of the heat transfer pipe (42). The amount of protrusion of the front connecting pipe (53) from the first left side surface (52c) is, for example, 5 mm or more. The amount of protrusion of the front main connecting pipe (53a) from the first left side surface (52c) is the same as the amount of protrusion of the front auxiliary connecting pipe (53b) from the first left side surface (52c).

[0070] The front connecting pipe (53) forms a ridgeline with the first left side surface (52c). The angle between the side surface of the front connecting pipe (53) and the first left side surface (52c) is 90° or slightly greater than 90°.

[0071] The thickness of the front connecting pipe (53) is equal to or thinner than the thickness of the first front plate (521). The thickness of the front connecting pipe (53) is equal to or greater than 0.4 mm.

[0072] The front connecting pipe (53) is seamlessly molded integrally with the first front plate (521). More specifically, the front connecting pipe (53) and the first front plate (521) are configured as a single member. The front connecting pipe (53) and the first front plate (521) are molded integrally by, for example, casting or sintering metal powder using a 3D printer.

[0073] 10, the tip of the front connecting pipe (53) is inserted into the end of the corresponding heat transfer pipe (42). In other words, the end of the heat transfer pipe (42) is inserted outside the front connecting pipe (53). The front connecting pipe (53) is inserted into the flare portion (42a) of the corresponding heat transfer pipe (42). The front connecting pipe (53) is inserted into the flare portion (42a) and joined to the cylindrical portion (42c) of the flare portion (42a) by burner brazing.

[0074] As shown in FIG. 8, the front relay portion (54) is a circular pipe. The front relay portion (54) is provided on the fifth front plate (525) and disposed on the first right side surface (52d) of the front main body portion (52). In the front plate stack (50), the first internal piping (38) is connected to the first right side surface (52d) of the front plate stack (50). The front relay portion (54) is located in a rear portion of the boundary between the first overlapping portion (52a) and the second overlapping portion (52b) of the fifth front plate (525). The amount of protrusion of the front relay portion (54) from the first right side surface (52d) is smaller than the amount of protrusion of the front connecting pipe (53) from the first left side surface (52c). The front relay portion (54) is joined to an end of the first internal piping (38) by brazing.

[0075] The liquid end portion (55) is a circular pipe. The liquid end portion (55) is provided on the fifth front plate (525) and disposed on the first right side surface (52d) of the front main body portion (52). The liquid end portion (55) is located in the second overlapping portion (52b) of the fifth front plate (525). The amount by which the liquid end portion (55) protrudes from the first right side surface (52d) is the same as the amount by which the front relay portion (54) protrudes from the first right side surface (52d). The liquid end portion (55) is joined to the end portion of the liquid relay pipe (13a) by brazing.

[0076] At the position of the liquid end (55), the refrigerant flow path (51) of the front plate assembly (50) extends straight in the stacking direction of the front plates without being connected to other refrigerant flow paths (51). The refrigerant flow path (51) at the position of the liquid end (55) communicates with the heat transfer tube (42) located lowest in the second auxiliary heat exchange section (45).

[0077] The front relay part (54) and the liquid end part (55) are molded seamlessly and integrally with the fifth front plate (525). More specifically, the front relay part (54), the liquid end part (55), and the fifth front plate (525) are configured from a single member. The front relay part (54) and the liquid end part (55) are molded integrally with the fifth front plate (525) by burring the fifth front plate (525). The front relay part (54) and the liquid end part (55) may be molded integrally with the fifth front plate (525) by casting or sintering metal powder using a 3D printer.

[0078] (4-2) Rear plate assembly The rear plate stack (60) includes a rear main body portion (62) having a refrigerant flow path (61) therein, a plurality of rear connecting pipes (63) connecting the plurality of heat transfer tubes (42) of the rear heat exchange portion (40B) to the refrigerant flow path (61), a rear relay portion (64) to which the second internal piping (39) is connected, and a gas end portion (65) communicating with the first connection piping (12) via the gas relay pipe (12a).

[0079] The rear body portion (62) has basically the same configuration as the front body portion (52), except that the shape of the outer edge of the plate as viewed in the axial direction of the heat transfer tubes (42) and the internal refrigerant flow paths (61) are different from those of the front body portion (52). The rear body portion (62) is a thick plate-like member formed by stacking five rear plates. The stacking direction of the rear plates is the same as the axial direction of the heat transfer tubes (42). In the rear plate stack (60), a first rear plate (621), a second rear plate (622), a third rear plate (623), a fourth rear plate (624), and a fifth rear plate (625) 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). The rear plates are made of the same material as the heat transfer tube (42) and the rear connecting tube (63). In this embodiment, the rear plates are made of an aluminum alloy. The first rear plate (621) and the fifth rear plate (625) have a thickness of 1.5 mm. The second rear plate (622), the third rear plate (623), and the fourth rear plate (624) have a thickness of 3.0 mm. The five rear plates are joined to each other by furnace brazing. Note that the number of rear plates is an example, and the number of rear plates may be four or less, or six or more. The number of front plates and the number of rear plates may be different. Hereinafter, when there is no need to distinguish between the rear plates, they will simply be referred to as rear plates.

[0080] The rear main body portion (62) has a second left side surface (62a) which is a surface of the rear heat exchanger portion (40B) in the axial direction of the heat transfer tube (42), a second right side surface (62b) which is a surface opposite to the second left side surface (62a) in the axial direction, and a second peripheral surface (62c) which is a peripheral surface extending between the second left side surface (62a) and the second right side surface (62b). The second left side surface (62a) is a surface of the first rear plate (621) on the side of the rear heat exchanger portion (40B). The second left side surface (62a) is a surface of the fifth rear plate (625) which is opposite to the fourth rear plate (624). The second peripheral surface (62c) is a surface formed by the side surfaces of the respective rear plates (621, 622, 623, 624, 625). The second left side surface (62a) corresponds to the first surface, and the second right side surface (62b) corresponds to the second surface.

[0081] The rear connecting pipes (63) are circular pipes made of an aluminum alloy. As shown in Fig. 11, the rear connecting pipes (63) are arranged in a manner corresponding to the arrangement of the heat transfer tubes (42) of the rear heat exchange section (40B).

[0082] The rear connecting pipes (63) include a rear main connecting pipe (63a) connected to the rear main heat exchange section (46) and a rear auxiliary connecting pipe (63b) connected to the third auxiliary heat exchange section (47). The outer diameter of the rear main connecting pipe (63a) is the same as that of the rear auxiliary connecting pipe (63b). The outer diameters of the rear main connecting pipe (63a) and the rear auxiliary connecting pipe (63b) are larger than the outer diameter of the front main connecting pipe (53a). The outer diameters of the rear main connecting pipe (63a) and the rear auxiliary connecting pipe (63b) are, for example, 7 mm. In the following description, when there is no need to distinguish between the rear main connecting pipe (63a) and the rear auxiliary connecting pipe (63b), they are simply referred to as the rear connecting pipe (63).

[0083] The amount by which the rear connecting pipe (63) protrudes from the second left side surface (62a) is, for example, 5 mm or more. The amount by which the rear main connecting pipe (63a) protrudes from the second left side surface (62a) is the same as the amount by which the rear auxiliary connecting pipe (63b) protrudes from the second left side surface (62a).

[0084] The rear connecting pipe (63) forms a ridgeline with the second left side surface (62a). The angle between the side surface of the rear connecting pipe (63) and the second left side surface (62a) is 90° or slightly greater than 90°.

[0085] The wall thickness of the rear connecting pipe 63 is equal to or thinner than the thickness of the first rear plate 621. The wall thickness of the rear connecting pipe 63 is equal to or greater than 0.4 mm.

[0086] The rear connecting pipe (63) is integrally molded with the first rear plate (621) without any seams. More specifically, the rear connecting pipe (63) and the first rear plate (621) are configured from a single member. No seam is formed between the rear connecting pipe (63) and the first rear plate (621). The rear connecting pipe (63) and the first rear plate (621) are integrally molded by, for example, casting or sintering metal powder using a 3D printer.

[0087] In the rear plate assembly 60, the rear connecting pipes 63 are inserted into the ends of the heat transfer tubes 42. The rear connecting pipes 63 are inserted into the flared portions 42a of the corresponding heat transfer tubes 42. The rear connecting pipes 63 are inserted into the flared portions 42a and joined to the cylindrical portions 42c of the flared portions 42a by burner brazing.

[0088] The rear relay portion (64) is a circular pipe. As shown in FIG. 6, the rear relay portion (64) is provided on the fifth rear plate (625) and disposed on the second right side surface (62b) of the rear main body portion (62). That is, in the rear plate stack (60), the second internal pipe (39) that connects the refrigerant flow path (51) of the front plate stack (50) and the refrigerant flow path (61) of the rear plate stack (60) is connected to the second right side surface (62b) of the rear plate stack (60). The amount of protrusion of the rear relay portion (64) from the second right side surface (62b) is smaller than the amount of protrusion of the rear connecting pipe (63) from the second left side surface (62a). The rear relay portion (64) is joined to an end of the second internal pipe (39) by brazing.

[0089] The gas end portion (65) is a circular pipe. The gas end portion (65) is provided on the fifth rear plate (625) and disposed on the second right side surface (62b) of the rear main body portion (62). The amount of protrusion of the gas end portion (65) from the second right side surface (62b) is the same as the amount of protrusion of the gas end portion (65) from the second right side surface (62b) of the rear relay portion (64). The gas end portion (65) is joined to an end portion of the gas relay pipe (12a) by brazing.

[0090] The rear relay part (64) and the gas end part (65) are molded seamlessly and integrally with the fifth rear plate (625). More specifically, the rear relay part (64), the gas end part (65), and the fifth rear plate (625) are configured from a single member. The rear relay part (64) and the gas end part (65) are molded integrally with the fifth rear plate (625) by burring the fifth rear plate (625). The rear relay part (64) and the gas end part (65) may be molded integrally with the fifth rear plate (625) by casting or sintering metal powder using a 3D printer.

[0091] (5) Driving behavior The air conditioner (10) performs a cooling operation, a heating operation, and a dehumidifying operation.

[0092] (5-1) Cooling operation In the cooling operation, the controller of the air conditioner (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 FIG. 1), appropriately adjusts the opening degree of the outdoor expansion valve (23), and fully opens the indoor expansion valve (37).

[0093] In the 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.

[0094] The indoor unit (30) draws indoor air from the indoor space (I) into the air passage (P) through the inlet (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) through the air outlet (34).

[0095] (5-2) Heating operation In the heating operation, the controller of the air conditioner (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 FIG. 1), adjusts the opening degree of the outdoor expansion valve (23) to a predetermined opening degree, and fully opens the indoor expansion valve (37).

[0096] In the heating operation, the refrigerant circuit (11) performs a refrigeration cycle in which the indoor heat exchanger (40) functions as a condenser (heat radiator) and the outdoor heat exchanger (22) functions as an evaporator.

[0097] The indoor unit (30) draws indoor air from the indoor space (I) into the air passage (P) through the inlet (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) through the air outlet (34).

[0098] (5-3) Dehumidification operation In the dehumidification operation, a controller of the air conditioner (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 FIG. 1), and appropriately adjusts the openings of the outdoor expansion valve (23) and the indoor expansion valve (37).

[0099] 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 a condenser (heat radiator), and the rear heat exchange section (40B) of the indoor heat exchanger (40) functions as an evaporator.

[0100] The indoor unit (30) draws room air from the indoor space (I) into the air passage (P) through the inlet (33). The rear heat exchange section (40B) cools the air in the air passage (P) to a temperature equal to or lower than the dew point temperature. The front heat exchange section (40A) heats the air in the air passage (P). The air that has passed through both sections mixes in the air passage (P) to become low-humidity air. The air dehumidified in this manner is supplied to the indoor space (I) through the air outlet (34).

[0101] (6) Effects of the embodiment In the present embodiment, the front plate stack (50) is formed integrally with the front main body portion (52) and the front connecting pipe (53), which prevents the axis of the front connecting pipe (53) from shifting or from tilting obliquely with respect to the first left side surface (52c) of the front main body portion (52). This prevents pitch deviation between the front connecting pipe (53) and the heat transfer tube (42), improving the ease of inserting the front connecting pipe (53) into the heat transfer tube (42).

[0102] As for the rear plate stack (60), the rear main body portion (62) and the rear connecting pipe (63) are integrally molded, so that pitch deviation between the rear connecting pipe (63) and the heat transfer pipe (42) is suppressed, improving the insertability of the rear connecting pipe (63) into the heat transfer pipe (42).

[0103] In this embodiment, the fins (41) of the front heat exchange section (40A) have a first portion (41a) whose longitudinal direction is the first direction (D1) and a second portion (41b) whose longitudinal direction is the second direction (D2) when viewed in the axial direction of the heat transfer tube (42), the heat transfer tube (42) is arranged in both the first portion (41a) and the second portion (41b), the front main body portion (52) has a first overlapping portion (52a) overlapping with the first portion (41a) when viewed in the axial direction of the heat transfer tube (42) and a second overlapping portion (52b) that is integral with the first overlapping portion (52a) and overlaps with the second portion (41b) when viewed in the axial direction of the heat transfer tube (42), and the multiple front connecting tubes (53) are arranged in both the first overlapping portion (52a) and the second overlapping portion (52b). In this configuration, if the front connecting pipe (53) is separate from the front main body portion (52), pitch misalignment is likely to occur between the heat transfer tubes (42) and the front connecting pipe (53). In particular, at the boundary between the first overlapping portion (52a) and the second overlapping portion (52b), the arrangement of the front connecting pipe (53) changes, and thus pitch misalignment is likely to occur between the heat transfer tubes (42) and the front connecting pipe (53). If the front main body portion (52) and the front connecting pipe (53) are integrally molded, the position of the front connecting pipe (53) is unlikely to be misaligned, and therefore, even if the arrangement of the heat transfer tubes (42) is complex, pitch misalignment between the front connecting pipe (53) and the heat transfer tube (42) is suppressed. This improves the ease of inserting the front connecting pipe (53) into the heat transfer tube (42).

[0104] In this embodiment, the amount of protrusion of the front connecting pipe (53) from the first left side surface (52c) is 5 mm or more. If the front connecting pipe (53) has a certain length, and if the front connecting pipe (53) is separate from the front main body portion (52), the axis of the front connecting pipe (53) is likely to tilt obliquely with respect to the first left side surface (52c). If the front main body portion (52) and the front connecting pipe (53) are integrally molded, the axis of the front connecting pipe (53) can be prevented from tilting with respect to the first left side surface (52c), and pitch deviation can be suppressed. In addition, since the front connecting pipe (53) has a certain length, the position of the front connecting pipe (53) when viewed from the side can be easily grasped, and the front connecting pipe (53) can be easily inserted into the heat transfer pipe (42).

[0105] The rear connecting pipe (63) also protrudes from the second left side surface (62a) by 5 mm or more. By integrally molding the rear main body portion (62) and the rear connecting pipe (63), pitch deviation is suppressed even if the rear connecting pipe (63) has a certain length. In addition, the position of the rear connecting pipe (63) when viewed from the side is easily grasped, improving the ease of inserting the rear connecting pipe (63) into the heat transfer pipe (42).

[0106] In this embodiment, the front connecting pipe (53) includes a front main connecting pipe (53a) and a front auxiliary connecting pipe (53b) having an outer diameter different from that of the front main connecting pipe (53a). If the front connecting pipe (53) is separate from the front body portion (52), it is difficult to align the front main connecting pipe (53a) and the front auxiliary connecting pipe (53b). If the front body portion (52) and the front connecting pipe (53) are integrally molded, the positions of the front main connecting pipe (53a) and the front auxiliary connecting pipe (53b) can be easily determined, and therefore, pitch deviation between the front connecting pipe (53) and the heat transfer pipe (42) can be suppressed.

[0107] In the present embodiment, when the front connecting pipe (53) and the rear connecting pipe (63) are made of aluminum, the wall thickness of the front connecting pipe (53) and the wall thickness of the rear connecting pipe (63) are 0.4 mm or more. This makes it possible to improve the strength of the front connecting pipe (53) and the rear connecting pipe (63) while suppressing pitch deviation between the front connecting pipe (53) and the heat transfer tube (42) and between the rear connecting pipe (63) and the heat transfer tube (42).

[0108] In this embodiment, the heat transfer tube (42) is inserted onto the front connecting tube (53). At the connection portion between the heat transfer tube (42) and the front connecting tube (53), the inner diameter of the heat transfer tube (42) is larger than the outer diameter of the front connecting tube (53). This improves the ease of inserting the front connecting tube (53) into the heat transfer tube (42). In addition, since the front connecting tube (53) is inserted into the heat transfer tube (42), it is easier to grasp the insertion position of the front connecting tube (53) than when the front connecting tube (53) is inserted onto the heat transfer tube (42). This improves the ease of inserting the front connecting tube (53) into the heat transfer tube (42).

[0109] In addition, the heat transfer tube (42) is inserted onto the rear connecting tube (63), which improves ease of insertion of the rear connecting tube (63) into the heat transfer tube (42).

[0110] In the present embodiment, the heat transfer tube (42) has a flare portion (42a) at a connection portion between the front connecting tube (53) and the rear connecting tube (63). The presence of the flare portion (42a) in the heat transfer tube (42) makes it easier to insert the front connecting tube (53) and the rear connecting tube (63) into the heat transfer tube (42). This improves the ease of inserting the front connecting tube (53) and the rear connecting tube (63) into the heat transfer tube (42).

[0111] In this embodiment, the cooling system includes a front plate stack (50) connected to the heat transfer tubes (42) of the front heat exchange section (40A) and a rear plate stack (60) connected to the heat transfer tubes (42) of the rear heat exchange section (40B), and a first internal pipe (38) and a second internal pipe (39) connecting a refrigerant flow path (51) of the front plate stack (50) and a refrigerant flow path (61) of the rear plate stack (60) are connected to a first right side surface (52d) of the front plate stack (50) and a second right side surface (62b) of the rear plate stack (60). Since the first internal pipe (38) is connected to the first right side surface (52d), the connection portion between the front main body portion (52) and the first internal pipe (38) does not affect the arrangement of the front connecting pipe (53). Furthermore, by connecting the second internal piping (39) to the second right side surface (62b), the connection portion between the rear main body portion (62) and the second internal piping (39) does not affect the arrangement of the rear connecting pipe (63). This makes it possible to effectively suppress pitch misalignment between the front connecting pipe (53) and the heat transfer pipe (42) and between the rear connecting pipe (63) and the heat transfer pipe (42).

[0112] (7) Variations The above-described indoor heat exchanger (40) may have the following modified configuration. The following describes the differences from the above-described embodiment.

[0113] In the modified example, the configuration of the front body portion (252) is different from that of the previously described embodiment. As shown in Fig. 12, in the modified example, the front body portion (252) is configured from a single plate, not a plate stack. The front body portion (252) has a refrigerant flow path formed therein, as in the previously described embodiment. The front plate structure (250) having the front body portion (252) is manufactured by sintering metal powder using a 3D printer.

[0114] In this modification, since there is no brazed portion in the front main body portion (252), there is no problem even if heat is transferred to the front main body portion (252) when the front connecting pipe (53) and the heat transfer pipe (42) are brazed together. For this reason, the amount of protrusion of the front connecting pipe (53) from the first left side surface may be as short as possible, in particular, less than 5 mm. This allows the indoor heat exchanger (40) to have a compact configuration.

[0115] (8) Other embodiments The refrigeration cycle device may be any device that performs a vapor compression refrigeration cycle, and is not limited to an air conditioner. The refrigeration cycle device may be a cooling device that cools the interior of a refrigerator or a refrigerated warehouse, a chiller device that cools or heats a heat medium such as water, or a heat pump type water heater that heats water to generate hot water.

[0116] The air conditioner (10) does not have to be of a pair type, but may be of a multi-type.

[0117] The indoor unit (30) may be of a ceiling-mounted or floor-standing type.

[0118] The direction in which the first heat exchange section (40A) and the second heat exchange section (40B) are arranged is not limited to the front-rear direction, but may be, for example, the up-down direction.

[0119] The heat exchanger may be applied to an outdoor heat exchanger (22) of an outdoor unit (20).

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

[0121] The heat exchanger body (B) may have one heat exchange section, without including the front heat exchange section (40A) and the rear heat exchange section (40B). In this case, the first internal pipe (38), the second internal pipe (39), and the indoor expansion valve (37) are omitted.

[0122] The fins (41) and the heat transfer tubes (42) of the heat exchanger body (B) may be made of a copper alloy instead of an aluminum alloy. When the heat transfer tubes (42) are made of a copper alloy, the plate stacks (50, 60) are also made of a copper alloy. When the plates are made of a copper alloy, the plate thickness is 0.8 mm. When the front connecting pipe (53) and the rear connecting pipe (63) are made of a copper alloy, the wall thickness of the front connecting pipe (53) and the rear connecting pipe (63) is 0.2 mm or more.

[0123] The fins (41) and the heat transfer tubes (42) of the heat exchanger body (B) may be made of stainless steel (SUS) material instead of aluminum material. When the heat transfer tubes (42) are made of stainless steel, the plate stacks (50, 60) are also made of stainless steel. When the plates are made of stainless steel, the plate thickness is 0.4 mm. When the front connecting pipe (53) and the rear connecting pipe (63) are made of stainless steel, the wall thickness of the front connecting pipe (53) and the rear connecting pipe (63) is 0.1 mm or more.

[0124] Although the embodiments and modifications have been described above, it will be understood that various modifications of form and details are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments, modifications, and other embodiments may be appropriately combined or substituted as long as the functions of the subject of the present disclosure are not impaired.

[0125] The descriptions "first," "second," "third," etc. mentioned above are used to distinguish the words to which these descriptions are attached, and do not limit the number or order of the words. [Industrial Applicability]

[0126] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for a heat exchanger, a refrigeration cycle device, and an air conditioner indoor unit. [Explanation of symbols]

[0127] 11 Refrigerant circuit 31 Casing 40 Indoor heat exchanger 40A Front heat exchanger 40B Rear heat exchange section 41 Finn 41a Part 1 41b Part 2 42 Heat transfer tube 42a Flare section 50 Front plate stack 51 Coolant flow path 52 Front main body 52a 1st overlap part 52b 2nd overlap part 52c 1st left side 52d 1st right side 53 First connecting pipe 53a First main connecting pipe 53b First auxiliary connecting pipe 60 Rear plate stack 61 Coolant flow path 521 First front plate 522 Second front plate 523 3rd front plate 524 4th front plate 525 5th front plate D1 1st direction D2 2nd direction

Claims

1. a heat exchange section (40A) having fins (41) and a plurality of heat transfer tubes (42); a plate structure (50) that is arranged so as to overlap the heat exchange portion (40A) in the axial direction of the heat transfer tubes (42) and that defines therein a refrigerant flow path (51) that connects the heat transfer tubes (42), The plate structure (50) comprises: a main body (52) having a first surface (52c) which is a surface of the heat transfer tube (42) facing the heat exchange portion (40A) in the axial direction, and a second surface (52d) which is a surface on the opposite side to the first surface (52c) in the axial direction, and having the refrigerant flow path (51) therein; a plurality of connecting pipes (53) arranged on the first surface (52c) and connecting the plurality of heat transfer pipes (42) and the refrigerant flow path (51); having The main body (52) and the connecting pipe (53) are integrally formed in the heat exchanger.

2. 2. The heat exchanger according to claim 1, The fin (41) is a first portion (41a) having a longitudinal direction in a first direction (D1) as viewed in the axial direction of the heat transfer tube (42); a second portion (41b) having a longitudinal direction in a second direction (D2) intersecting the first direction (D1) when viewed from the axial direction; having the plurality of heat transfer tubes (42) are arranged in both the first portion (41a) and the second portion (41b), The main body portion (52) is a first overlapping portion (52a) overlapping with the first portion (41a) as viewed in the axial direction; a second overlapping portion (52b) which is integral with the first overlapping portion (52a) and overlaps with the second portion (41b) when viewed in the axial direction; having The plurality of connecting pipes (53) are arranged in both the first overlapping portion (52a) and the second overlapping portion (52b).

3. 3. The heat exchanger according to claim 1, A heat exchanger, wherein the connecting pipe (53) protrudes from the first surface (52c) by an amount of 5 mm or more.

4. 3. The heat exchanger according to claim 1, The connecting pipe (53) is a heat exchanger including connecting pipes (53a, 53b) having different outer diameters.

5. 3. The heat exchanger according to claim 1, The connecting pipe (53) is made of aluminum, A heat exchanger, wherein the connecting pipe (53) has a wall thickness of 0.4 mm or more.

6. 3. The heat exchanger according to claim 1, The connecting pipe (53) is made of copper, A heat exchanger, wherein the connecting pipe (53) has a wall thickness of 0.2 mm or more.

7. 3. The heat exchanger according to claim 1, The heat transfer tube (42) is inserted onto the connecting tube (53).

8. 8. The heat exchanger according to claim 7, A heat exchanger in which the heat transfer tube (42) and the connecting tube (53) are connected to each other has a flare portion (42a).

9. 3. The heat exchanger according to claim 1, The body portion (52) is a plate stack in which a plurality of plates (521, 522, 523, 524, 525) are stacked, A heat exchanger in which the plate (521) constituting the first surface (52c) and the connecting pipe (53) are integrally formed by casting.

10. 3. The heat exchanger according to claim 1, The body (52) and the connecting pipe (53) of the heat exchanger are integrally formed by sintering.

11. 3. The heat exchanger according to claim 1, The heat exchange section (40A, 40B) includes a first heat exchange section (40A) and a second heat exchange section (40B) arranged in a direction perpendicular to an axial direction of the heat transfer tube (42), the plate structures (50, 60) include a first plate structure (50) connected to the heat transfer tubes (42) of the first heat exchange section (40A) and a second plate structure (60) connected to the heat transfer tubes (42) of the second heat exchange section (40B), A refrigerant pipe (38) connecting the refrigerant flow path (51) of the first plate structure (50) and the refrigerant flow path (61) of the second plate structure (60) is a heat exchanger connected to the second surface (52d) of the first plate structure (50) and the second surface (62b) of the second plate structure (60).

12. A refrigeration cycle apparatus comprising a refrigerant circuit (11) to which the heat exchanger (40) according to claim 1 or 2 is connected.

13. A heat exchanger (40) according to claim 1 or 2; and a casing (31) that houses the heat exchanger (40).

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