Indoor heat exchanger and air-conditioning indoor machine

Abstract

A plate laminate (50, 60) of this indoor heat exchanger has: a first plate part (50A, 60A) having one or more plates (52, 62) and disposed adjacent to a heat exchange part (B) in a first direction; and a second plate part (50B, 60B) having one or more plates (52, 62) and disposed on a surface of the first plate part (50A, 60A) opposite to a surface facing the heat exchange part (B). A step part (X) is formed at the peripheral edge portion of a first surface (501, 601) facing the heat exchange part (B) in the plate laminate (50, 60). The step part (X) is formed by the first plate part (50A, 60A) and the second plate part (50B, 60B).

Description

Indoor heat exchanger and air conditioning indoor unit

[0001] The present disclosure relates to an indoor heat exchanger and an air conditioning indoor unit.

[0002] Patent Document 1 discloses a stacked header connected to a heat exchanger. Each plate constituting the stacked header has a groove formed therein. By stacking multiple plates with such grooves, the grooves form refrigerant flow paths inside the stacked header.

[0003] International Publication No. 2014 / 184917

[0004] All plates that make up the plate stack are formed to have the same shape. The shape and position of the grooves formed in the plates vary depending on the structure of the refrigerant flow path. Therefore, the area of ​​the region without grooves varies depending on the plate. Since the region without grooves has no use, if that region is relatively large, the space inside the air conditioner cannot be used effectively.

[0005] An object of the present disclosure is to provide an indoor heat exchanger having stacked plates that can effectively utilize the space inside an air conditioner.

[0006] The first aspect of the present invention is a heat exchanger including a heat exchange section (B) including a plurality of fins (41) and a plurality of heat transfer tubes (42) penetrating the plurality of fins (41); and a plate stack (50, 60) having a plurality of plates (52, 62) stacked in a first direction in which the heat transfer tubes (42) extend, with a flow path (51, 61) provided therein and communicating with the heat transfer tubes (42), wherein the plate stack (50, 60) includes: a first plate section (50A, 60A) arranged adjacent to the heat exchange section (B) in the first direction and having one or more of the plates (52, 62); an indoor heat exchanger including one or more plates (52, 62) having a shape different from that of the plates (52, 62) of the first plate portion (50A, 60A) and a second plate portion (50B, 60B) arranged on a surface of the first plate portion (50A, 60A) opposite to a surface facing the heat exchange portion (B); a step portion (X) is formed on a peripheral portion of a first surface (501, 601) of the plate stack (50, 60) facing the heat exchange portion (B); and the step portion (X) is formed by the first plate portion (50A, 60A) and the second plate portion (50B, 60B).

[0007] In the first aspect, by providing a step portion (X) in the plate stack (50, 60), a space can be formed at a position opposite the step portion (X). This space can be effectively utilized, for example, by arranging a predetermined component in the space.

[0008] A second aspect is the first aspect, wherein the plate stack (50, 60) is composed of three or more of the plates (52, 62), and in the plate stack (50, 60), the plate (52, 62) of the first plate portion (50A, 60A) closest to the heat exchange portion (B) is defined as a first end plate (521), and the plate (52, 62) of the second plate portion (50B, 60B) farthest from the heat exchange portion (B) is defined as a second end plate (525), and the plate (52, 62) arranged between the first end plate (521) and the second end plate (525) is defined as an intermediate plate (522-524), the flow path (51, 61) is formed to pass through the intermediate plates (522-524, 622-624), The thickness of the intermediate plates (522 to 524) is greater than the thickness of the first end plate (521) and the second end plate (525).

[0009] In the second aspect, the thickness of the central plate (52, 62) of the plate stack (50, 60) is made thicker than the thickness of the plates (52, 62) arranged at both ends of the plate stack (50, 60), thereby making it possible to increase the cross-sectional area or inner diameter of the refrigerant flow paths (51, 61) formed in the plate stack (50, 60), thereby suppressing an increase in pressure loss of the refrigerant flowing through the refrigerant flow paths (51, 61).

[0010] A third aspect is the first or second aspect, wherein at least a part of a first surface (501, 601) and a second surface (502, 602) opposite to the first surface (501, 601) of the plate stack (50, 60) is subjected to anticorrosion treatment.

[0011] In the third aspect, although there is a risk of electrolytic corrosion on both side surfaces of the plate stack (50, 60) due to condensation or the like, such electrolytic corrosion can be suppressed by the anticorrosion treatment.

[0012] A fourth aspect is any one of the first to third aspects, wherein, when the plate stack (50, 60) is viewed from the opposite side to the first direction, the area of ​​the portion of the second plate portion (50B, 60B) that is not overlapped with the first plate portion (50A, 60A) is smaller than the area of ​​the portion that is overlapped with the first plate portion (50A, 60A).

[0013] The overlapping portions of the plate stack (50, 60) where the first plate portions (50A, 60A) and the second plate portions (50B, 60B) are thicker than the portions consisting of only the first plate portions (50A, 60A), and therefore a larger number of flow paths (51, 61) can be formed. This increases the number of refrigerant flow paths in the heat transfer tubes (42) of the heat exchange section (B), thereby facilitating heat exchange. In the fourth aspect, the overlapping portions of the first plate portions (50A, 60A) and the second plate portions (50B, 60B) are wider than the portions consisting of only the first plate portions (50A, 60A), thereby ensuring a sufficient number of flow paths in the plate stack (50, 60), and thereby facilitating heat exchange between the air and the refrigerant in the indoor heat exchanger.

[0014] A fifth aspect is any one of the first to fourth aspects, wherein the flow paths (51, 61) include a first flow path (51A) provided in the first plate portion (50A, 60A) and a second flow path (51B) provided across the first plate portion (50A, 60A) and the second plate portion (50B, 60B), and the second flow path (51B) is formed so as to intersect with the first flow path (51A).

[0015] In the fifth aspect, in the portion of the plate stack (50, 60) where the flow paths (51, 61) do not intersect, it is sufficient to provide the flow paths (51, 61) only in the first plate portion (50A, 60A). In such a portion, the second plate portion (50B, 60B) is not required, and therefore, the step portion (X) can be provided. In this way, the space formed by the step portion (X) can be effectively utilized.

[0016] A sixth aspect is any one of the first to fifth aspects, wherein the heat exchange section (B) is provided with a U-shaped connecting pipe (400) that is disposed between the heat exchange section (B) and the plate stack (50, 60) and connects the two heat transfer tubes (42) together, and the connecting pipe (400) is provided at a position facing the step portion (X) when viewed from the opposite side of the first direction.

[0017] The gap between the heat exchange section (B) and the plate stack (50, 60) needs to be large enough to accommodate the U-shaped connecting pipe (400), but in the sixth aspect, the connecting pipe (400) is provided in the space formed by the step portion (X), so that the gap between the heat exchange section (B) and the plate stack (50, 60) can be made relatively small, thereby enabling the indoor heat exchanger to be made compact.

[0018] A seventh aspect is the sixth aspect, further comprising a detector (70) for detecting the temperature of the refrigerant flowing through the heat transfer pipe (42), wherein the detector (70) is provided on the connecting pipe (400).

[0019] In the seventh aspect, the space formed by the step portion (X) can be effectively utilized to provide the detection portion (70).

[0020] An eighth aspect is the sixth or seventh aspect, wherein, when the indoor heat exchanger functions as an evaporator, a refrigerant in a superheated region flows through the connecting pipe (400), and when the indoor heat exchanger functions as a radiator, a refrigerant in a subcooled region flows through the connecting pipe (400).

[0021] The temperature of the refrigerant in the superheated region is relatively high, and the temperature of the refrigerant in the supercooled region is relatively low. Therefore, if there is another flow path near the flow path through which the refrigerant in the superheated region or the supercooled region passes, the refrigerant passing through that flow path will exchange heat with the refrigerant passing through the refrigerant in the superheated region or the supercooled region. In contrast, in the eighth aspect, by flowing the refrigerant in the superheated region or the supercooled region through the connecting pipe (400), heat exchange with the refrigerant flowing through the flow path in the plate stack (50, 60) can be suppressed.

[0022] A ninth aspect is an indoor heat exchanger comprising: the indoor heat exchanger of any one of the first to eighth aspects; and a gas pipe (12a) that conveys compressed refrigerant gas to the indoor heat exchanger (40), wherein the gas pipe (12a) is connected to the flow path (51, 61) formed in a portion where the first plate portion (50A, 60A) and the second plate portion (50B, 60B) of the plate stack (50, 60) overlap.

[0023] In the ninth aspect, among the flow paths (51, 61) extending in the stacking direction of the plates (52, 62), the flow paths (51, 61) extending in the stacking direction between the first plate portion (50A, 60A) and the second plate portion (50B, 60B) are relatively long. Therefore, by flowing compressed gas refrigerant through such flow paths (51, 61), pressure loss of the gas refrigerant passing through the flow paths (51, 61) can be reduced.

[0024] FIG. 1 is a piping diagram of an air conditioning apparatus according to an embodiment. FIG. 2 is a front view of an air conditioning indoor unit. FIG. 3 is a cross-sectional view of the air conditioning indoor unit taken along line II-II. FIG. 4 is a front view showing the internal structure of the air conditioning indoor unit. FIG. 5 is an enlarged perspective view of a main portion of an indoor heat exchanger. FIG. 6 is a left-side view of a plate stack. FIG. 7 is a cross-sectional view illustrating an example of a refrigerant flow path in the plate stack. FIG. 8 is a schematic front view of a front plate stack. FIG. 9 is a cross-sectional view of the front plate stack for explaining the configuration of a first flow path. FIG. 10 is a cross-sectional view of the front plate stack for explaining the configuration of a second flow path. FIG. 11 is a schematic view of the plate stack from a first direction (rightward), showing the first and second flow paths intersecting. FIG. 12(a) is a perspective view and a plan view showing a state in which a temperature sensor is attached to a U-shaped connecting pipe. FIG. 12(b) is a plan view showing a state in which a temperature sensor is attached to a U-shaped connecting pipe. Fig. 13 is a schematic diagram of an indoor heat exchanger according to Modification 1, corresponding to Fig. 8. Fig. 14 is a schematic diagram of a main part of an indoor heat exchanger according to Modification 2, viewed from above.

[0025] Hereinafter, 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 concept of the present disclosure. Since the drawings are intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding.

[0026] (1) Overall Configuration of Air Conditioner This embodiment is an air conditioner (10) including a heat exchanger unit. The air conditioner (10) adjusts the temperature of air in an indoor space (I) which is a target space.

[0027] As shown in Fig. 1, the air conditioner (10) is an example of a refrigeration cycle apparatus 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.

[0028] The air conditioner (10) includes an air conditioning outdoor unit (20), an air conditioning indoor unit (30), a first interconnecting pipe (12), and a second interconnecting pipe (13). The air conditioner (10) is a pair type having one air conditioning outdoor unit (20) and one air conditioning indoor unit (30). The first interconnecting pipe (12) is a gas interconnecting pipe, and the second interconnecting pipe (13) is a liquid interconnecting pipe.

[0029] The air conditioner 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).

[0030] 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 selector valve (24) switches between a first state (the state indicated by the solid line in FIG. 1 ) and a second state (the state indicated by the dashed line in FIG. 1 ). In the first state, the four-way selector valve (24) communicates the discharge port of the compressor (21) with the gas end of the outdoor heat exchanger (22) and also communicates the suction port of the compressor (21) with the first connecting pipe (12). The four-way selector valve (24) in the second state communicates the discharge port of the compressor (21) with the first connecting pipe (12) and also communicates the suction port of the compressor (21) with the gas end of the outdoor heat exchanger (22). The outdoor fan (25) transports the air flowing through the outdoor heat exchanger (22). The outdoor fan (25) is a propeller fan.

[0031] The air conditioner 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).

[0032] (2) Air Conditioning Indoor Unit The air conditioning indoor unit (30), which is an indoor air conditioner, will be described in detail with reference to Figures 2 to 4. The air conditioning indoor unit (30) of this embodiment is a wall-mounted type that is installed 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 Figures 2 and 3, and the left-right directions are based on the case where the casing (31) is viewed from the front.

[0033] 2 and 3, the casing (31) is formed in the shape of a horizontally long box. The casing (31) 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).

[0034] 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).

[0035] An air inlet (33) is formed in the upper plate (31c), and an air outlet (34) is formed in the lower plate (31d). An air passage (P) is formed inside the casing (31) from the air inlet (33) to the air outlet (34). The air inlet (33) extends in the longitudinal direction of the casing (31). The air inlet (33) is an opening for taking air from the indoor space (I) into the air passage (P). An air outlet (34) is formed in the lower plate (31d). The air outlet (34) extends in the longitudinal direction of the casing (31). The air outlet (34) is an opening for blowing air from the air passage (P) into the indoor space (I).

[0036] (2-2) Filter The air conditioner indoor unit (30) includes a filter (35). The filter (35) is located at the back of the air inlet (33) and upstream of the indoor heat exchanger (40). The filter (35) collects dust in the air sent from the air inlet (33) to the indoor heat exchanger (40). The air conditioner indoor unit (30) may include a dust removal mechanism that removes the dust collected by the filter (35).

[0037] (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).

[0038] (2-4) Indoor Fan The indoor fan (32) is arranged in the air passage (P). The indoor fan (32) is arranged in the air passage (P) downstream of the indoor heat exchanger (40). 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).

[0039] (2-5) Flap The air conditioner indoor unit (30) has a flap (36) that adjusts the direction of air blown out from the air outlet (34). The flap (36) adjusts the air direction in the vertical direction. The air conditioner indoor unit (30) may have a plurality of flaps (36). The flap (36) may adjust the air direction in the horizontal direction.

[0040] (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).

[0041] (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.

[0042] The heat exchanger body (B) is an example of a heat exchange section (B). The heat exchanger body (B) includes a plurality of fins (41) and a plurality of heat transfer tubes (42) penetrating the plurality of fins (41). The plurality of fins (41) are arranged in the longitudinal direction of the casing (31). The plurality of heat transfer tubes (42) extend in the arrangement direction of the fins (41). The plate stack (50, 60) is provided therein with refrigerant flow paths (51, 61) that communicate with the heat transfer tubes (42). The refrigerant flow paths (51, 61) are an example of flow paths (51, 61).

[0043] The fins (41) are rectangular plates having long and short sides. The thickness direction of the fins (41) corresponds to the arrangement direction of the fins (41). The fins (41) are arranged at predetermined intervals in the thickness direction. These intervals define air flow paths. The fins (41) are made of an aluminum alloy.

[0044] The heat transfer tube (42) is a straight tube. The heat transfer tubes (42) are made of an aluminum alloy. A refrigerant flow path is formed inside the heat transfer tube (42). The heat transfer tubes (42) extend parallel to one another and penetrate the fins (41). One end of the heat transfer tube (42), i.e., the right end, protrudes to the right of the rightmost fin (41) among the fins (41). The end of the heat transfer tube protruding to the right is connected to the plate stack (50, 60).

[0045] Of the left ends of the plurality of heat transfer tubes (42), the 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 seamlessly as a single unit.

[0046] The indoor heat exchanger (40) of this embodiment has a front heat exchange section (40A) and a rear heat exchange section (40B). The front heat exchange section (40A) is located toward the front of the casing (31), and the rear heat exchange section (40B) is located toward the rear of the casing (31). The front heat exchange section (40A) and the rear heat exchange section (40B) are aligned 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) sandwiched between them.

[0047] 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).

[0048] The front main heat exchange section (43) is disposed in the front heat exchange section (40A) closer to the indoor fan (32). The front main heat exchange section (43) has a V-shaped outer shape when viewed in the longitudinal direction of the heat transfer tubes (42). The tip of the V faces forward.

[0049] The front main heat exchange section (43) is composed of a first front main heat exchange section (43a) and a second front main heat exchange section (43b). The first front main heat exchange section (43a) is located in the upper part of the front main heat exchange section (43), and the second front main heat exchange section (43b) is located in the lower part of the front main heat exchange section (43). The lower ends of the first front main heat exchange section (43a), i.e., the lower short sides of the fins (41), are in contact with the long sides of the fins (41) of the second front main heat exchange section (43b) (strictly speaking, the upper end portions of the long sides of the fins (41)).

[0050] 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 number of heat transfer tubes (42) in the first auxiliary heat exchange section (44) in a direction along the long sides (hereinafter referred to as the number of rows) is smaller than the number of rows of the heat transfer tubes (42) in the first front main heat exchange section (43a). The number of heat transfer tubes (42) in the first auxiliary heat exchange section (44) in a 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) in the first front main heat exchange section (43a).

[0051] 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 number of rows and columns of the heat transfer tubes (42) of the second auxiliary heat exchange section (45) is smaller than the number of rows and columns of the heat transfer tubes (42) of the second front main heat exchange section (43b).

[0052] 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 rows and columns of the heat transfer tubes (42) of the third auxiliary heat exchange section (47) is smaller than the number of rows and columns of the heat transfer tubes (42) of the rear main heat exchange section (46).

[0053] The plate stack (50, 60) is disposed to the right of the heat exchanger body (B) and adjacent to the heat exchanger body (B). The right side is an example of a first direction. Specifically, the plate stack (50, 60) is disposed to the right of the rightmost fin (41) of the multiple fins (41) and parallel to the fin (41). The plate stack (50, 60) is connected to the ends of the heat transfer tubes (42). As shown in FIG. 5 , the plate stack (50, 60) 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). The front plate stack (50) is disposed to overlap the front heat exchange section (40A) in the axial direction of the heat transfer tubes (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 tubes (42). The front plate stack (50) and the rear plate stack (60) will be described in detail later.

[0054] (3-2) Indoor Expansion Valve, Gas Relay Pipe, and Liquid Relay Pipe The indoor expansion valve (37) is an electronic expansion valve with a variable opening. The indoor expansion valve (37) is disposed on the right side of the plate stacks (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 examples of refrigerant pipes connecting the front refrigerant flow path (51) of the front plate stack (50) and the rear refrigerant flow path (61) of the rear plate stack (60).

[0055] (4) Plate Stack The gas relay pipe (12a) transports the refrigerant gas compressed by the compressor (21) to the indoor heat exchanger (40). The gas relay pipe (12a) is an example of a gas pipe (12a). One end of the gas relay pipe (12a) is connected to the rear plate stack (60). The other end of the gas relay pipe (12a) is connected to the first connecting pipe (12) via a joint. One end of the liquid relay pipe (13a) is connected to the front plate stack (50). The other end of the liquid relay pipe (13a) is connected to the second connecting pipe (13) via a joint.

[0056] The plate stack (50, 60) has therein a flow path (51, 61) that communicates with the heat transfer tube (42). The plate stack (50, 60) is configured such that a plurality of plates (52, 62) are stacked in the rightward direction. Details of the plate stack (50, 60) of this embodiment will be described below with reference to FIGS. 5 to 14.

[0057] (4-1) Front Plate Stack The front plate stack (50) includes a front refrigerant flow path (51), a front connecting pipe (53), a front relay section (54), and a liquid end portion (55). The front refrigerant flow path (51) is formed within the front plate stack (50). The front connecting pipe (53) connects the heat transfer tubes (42) of the front heat exchange section (40A) to the front refrigerant flow path (51). The front relay section (54) is connected to the first internal pipe (38). The liquid end portion (55) communicates with the second connection pipe (13) via the liquid relay pipe (13a). Hereinafter, the front plate stack (50) will be described as the plate stack (50, 60) of the present disclosure.

[0058] (4-1-1) First Plate Portion and Second Plate Portion As shown in FIGS. 5, 6, and 8, the front plate stack (50) has a front first plate portion (50A) and a front second plate portion (50B). The front first plate portion (50A) is an example of the first plate portion (50A, 60A) of the present disclosure. The front second plate portion (50B) is an example of the second plate portion (50B, 60B) of the present disclosure. The front first plate portion (50A) has two stacked front plates (52). The front second plate portion (50B) has three stacked front plates (52).

[0059] The outer edges of the front plates (52) of the front first plate portion (50A) have the same shape. The three front plates (52) of the front first plate portion (50A) are, from left to right, a first plate (521) and a second plate (522). A front connecting pipe (53) extending toward the right end of the heat transfer tube (42) is connected to the first plate (521). The interior of the front connecting pipe (53) defines a front refrigerant flow path (51), which will be described later.

[0060] The outer edges of the front plates (52) of the front second plate portion (50B) have the same shape. The three front plates (52) of the front second plate portion (50B) are referred to as a third plate (523), a fourth plate (524), and a fifth plate (525) from the left.

[0061] The shape of each of the front plates (521, 522) of the front first plate portion (50A) is different from the shape of each of the front plates (523, 524, 525) of the front second plate portion (50B). Specifically, the shape of the outer edge of the front first plate portion (50A) is different from the shape of the outer edge of the front second plate portion (50B).

[0062] The front second plate portion (50B) is arranged on the surface of the front first plate portion (50A) opposite to the surface facing the heat exchanger body (B). Specifically, the front second plate portion (50B) is arranged on the right side surface of the front first plate portion (50A).

[0063] Each of the front plates (521-525) is made of the same material as the heat transfer tube (42) and the front connecting pipe (53). In this embodiment, the material of each of the front plates (521-525) of the front first plate portion (50A) and the front second plate portion (50B) is an aluminum alloy.

[0064] When the front plate stack (50) is viewed from the left, the area of ​​the left side surface of the front first plate portion (50A) is smaller than the area of ​​the left side surface of the front second plate portion (50B). In other words, when viewed from the left, the front plate stack (50) has a first region (S1) where the front first plate portion (50A) and the front second plate portion (50B) do not overlap, and a second region (S2) where the front first plate portion (50A) and the front second plate portion (50B) overlap.

[0065] When the front plate assembly (50) is viewed from the opposite side to the right, i.e., from the left, the area of ​​the portion of the front second plate portion (50B) that is not overlapped with the front first plate portion (50A) is smaller than the area of ​​the portion that is overlapped with the front first plate portion (50A). In other words, the area of ​​the first region (S1) is smaller than the area of ​​the second region (S2).

[0066] As shown in FIG. 8 , the front plate stack (50) has a step (X). The step (X) is formed by the front first plate portion (50A) and the front second plate portion (50B). The step (X) is formed in the peripheral portion of the left side surface (501) of the front plate stack (50) that faces the heat exchanger body (B). The left side surface (501) of the front plate stack (50) is an example of a first surface (501). In other words, the step (X) is formed in the peripheral portion of the left side surface of the front plate stack (50). In further words, the step (X) is the portion where the first region (S1) is formed when the front plate stack (50) is viewed from the left. Specifically, the step (X) is formed by the first region (S1) and the first peripheral surface (P1) of the front second plate portion (50B). The first circumferential surface (P1) refers to a portion of the circumferential surface sandwiched between the right side surface and the left side surface of the front first plate portion (50A) that contacts the first region (S1).

[0067] The step portion (X) is formed in the lower part of the front plate stack (50) when viewed from the right. Specifically, the step portion (X) is formed in the front plate stack (50) below the height position of the center of the front plate stack (50). In other words, in the air conditioning indoor unit (30) of this embodiment, the air inlet (33), the front heat exchange section (40A), and the air outlet (34) are arranged in this order from top to bottom (see FIG. 3 ), and therefore the step portion (X) is formed in the front plate stack (50, 60) at a position close to the air outlet (34).

[0068] In this way, the first region (S1) is formed below the front second plate portion (50B). The overlapping portions of the front first plate portion (50A) and the front second plate portion (50B) on the peripheral surface of the front plate stack (50) are flush with each other. In other words, when the front plate stack (50) is viewed from the left, no region is formed where the front first plate portion (50A) and the front second plate portion (50B) do not overlap.

[0069] Furthermore, the first region (S1) only needs to be formed below the front first plate portion (50A) when the front plate stack (50) is viewed from the left, and the shape of the first region (S1) is not limited.

[0070] The front plate assembly (50) is anti-corrosion treated. Specifically, the entire left side surface (501) and the second region (S2) of the right side surface (502) of the front plate assembly (50, 60) are anti-corrosion treated. In this embodiment, an alloy plate having a sacrificial anti-corrosion effect is provided on the entire left side surface (501) and the second region (S2) of the right side surface (502) of the front plate assembly (50, 60). The alloy plate is made of, for example, a clad material having an aluminum core and a metal with a relatively high zinc content as a skin material. Note that the first region (S1) and the first peripheral surface (P1) do not require anti-corrosion treatment. This is because the third plate (523) constituting the first region (S1) is a thick intermediate plate (522-524). Similarly, the fourth plate (524) constituting a part of the first peripheral surface (P1) is also one of the thick intermediate plates (522-524).

[0071] Next, the plate thickness of each front plate (521-525) of the front plate stack (50) will be described. In the front plate stack (50), the front plate (52) of the front first plate portion (50A) closest to the heat exchanger body (B) is referred to as the first end plate, and the front plate (52) of the front second plate portion (50B) farthest from the heat exchanger body (B) is referred to as the second end plate. In this embodiment, the first end plate (521) is the first plate (521) located at the left end of the front first plate portion (50A), and the second end plate (525) is the fifth plate (525) located at the right end of the front second plate portion (50B).

[0072] In the front plate stack 50, the plates disposed between the first end plate 521 and the second end plate 525 are referred to as intermediate plates 522 to 524. In this embodiment, the intermediate plates 522 to 524 are the second plate 522, the third plate 523, and the fourth plate 524.

[0073] The thickness of each of the intermediate plates (522-524) is greater than the thickness of the first end plate (521) and the second end plate (525). In this embodiment, the thickness of each of the intermediate plates (522-524) is 3.0 mm, and the thickness of the first end plate (521) and the second end plate (525) is 1.5 mm.

[0074] (4-1-2) Configuration of Refrigerant Channel The configuration of the front refrigerant channel (51) of the plate stack (50, 60) of this embodiment will be described. The front refrigerant channel (51) is included in the refrigerant channel (51, 61) of the present disclosure. An example of the front refrigerant channel (51) will be described below.

[0075] 9 and 10 , the front refrigerant flow path (51) includes a first flow path (51A) provided in the front first plate portion (50A) and a second flow path (51B) provided across the front first plate portion (50A) and the front second plate portion (50B). The first flow path (51A) and the second flow path (51B) are provided in a portion overlapping with the front first plate portion (50A) and the front second plate portion (50B).

[0076] The first flow path (51A) is composed of two first through holes (71) passing through the first plate (521) located at the left end of the front first plate portion (50A) in the thickness direction, a first groove (81) formed in the second plate (522) located in the center, and a third plate (523) located at the right end. One end of the first through hole (71) communicates with one end of the heat transfer tube (42). The other end of the first through hole (71) is connected to the first groove (81).

[0077] The first groove (81) is an elongated hole formed along the surface of the first plate (521). One end of the first groove (81) is connected to one of the first through holes (71), and the other end of the first groove (81) is connected to the other first through hole (71). The first groove (81) is blocked from the left and right directions by the first plate (521) located at the left end and the first plate (521) located at the right end.

[0078] The second flow path (51B) is configured by a second through-hole (72) penetrating the front first plate portion (50A) in the thickness direction, a second groove (82) formed in a fourth plate (524) located at the left end of the front second plate portion (50B), and a fifth plate (525) located at the right end of the front second plate portion (50B). One end of the second through-hole (72) communicates with one end of the heat transfer tube (42). The other end of the second through-hole (72) is connected to the second groove (82). The second groove (82) is an elongated hole formed along the surface of the second plate (522). One end of the second groove (82) is connected to one of the second through-holes (72), and the other end of the second groove (82) is connected to the other of the second through-holes (72). The second groove (82) is closed from the left and right by the third plate (523) and the fifth plate (525).

[0079] In Fig. 11 , the first groove (81) is indicated by a dashed line, and the second groove (82) is indicated by a two-dot chain line. As shown in Fig. 11 , the first groove (81) and the second groove (82) are arranged to intersect when the front plate stack (50) is viewed from the left. That is, the second flow path (51B) intersects with the first flow path (51A). Specifically, the second flow path (51B) is formed to straddle the first flow path (51A) to the right.

[0080] 5 and 6 , the rear plate stack (60) includes a rear refrigerant flow path (61) formed inside the rear plate stack (60), a plurality of rear connecting pipes (not shown) connecting the heat transfer tubes (42) of the rear heat exchange section (40B) to the rear refrigerant flow path (61), a rear relay section (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). The rear refrigerant flow path (61) is included in the refrigerant flow paths (51, 61) of the present disclosure.

[0081] The rear plate stack (60) differs from the front plate stack (50) in the shape of the outer edges of the plates as viewed from the right and in the rear refrigerant flow paths (61) therein. The rear plate stack (60) is a thick plate-like member formed by stacking five rear plates (62) of the same shape. The rear plates (62) are stacked in the right direction.

[0082] The five rear plates (62) constituting the rear plate stack (60) are, from left to right, a sixth plate (621), a seventh plate (622), an eighth plate (623), a ninth plate (624), and a tenth plate (625) (see Figure 5).

[0083] As with the front plate stack (50, 60), the sixth plate (621) closest to the heat exchange section (B) is the first end plate (621), the tenth plate (625) farthest from the heat exchange section (B) is the second end plate (625), and the seventh to ninth plates (622 to 624) arranged between the sixth plate (621) and the tenth plate (625) are the intermediate plates (622 to 624). In this case, the thickness of each of the intermediate plates (622 to 624) is greater than the thickness of the sixth plate (621) and the tenth plate (625).

[0084] The rear plate assembly (50, 60) is subjected to the same corrosion prevention treatment as the front plate assembly (50, 60). Specifically, the alloy plates are attached to the left side surface (601) and the right side surface (602) of the rear plate assembly (60). The left side surface (601) and the right side surface (602) of the rear plate assembly (60) correspond to the first surface (601) and the second surface (602) of the present disclosure, respectively.

[0085] The rear relay portion (64) is a circular pipe. As shown in FIG. 5 , the rear relay portion (64) is disposed on the right side surface of the rear plate stack (60). That is, in the rear plate stack (60), the second internal pipe (39) connecting the front refrigerant flow path (51) of the front plate stack (50) and the rear refrigerant flow path (61) of the rear plate stack (60) is connected to the right side surface of the rear plate stack (60). The gas end portion (65) is a circular pipe. The gas end portion (65) is disposed on the right side surface of the rear plate stack (60).

[0086] (4-3) U-Shaped Connecting Pipe As shown in Fig. 8, the indoor heat exchanger (40) has a U-shaped connecting pipe (400) disposed between the heat exchanger body (B) and the front plate stack (50). Hereinafter, the U-shaped connecting pipe (400) will be referred to as the U-shaped connecting pipe (400).

[0087] The U-shaped connecting pipe (400) is provided in the heat exchanger body (B). The U-shaped connecting pipe (400) connects adjacent heat transfer tubes (42). The refrigerant flowing from the heat transfer tube (42) of the heat exchanger body (B) into the U-shaped connecting pipe (400) does not pass through the plate stacks (50, 60) but flows into the adjacent heat transfer tube (42) and then flows through the heat exchanger body (B).

[0088] The U-shaped connecting pipe (400) is provided at a position opposite to the right, i.e., facing the step portion (X) when viewed from the left. Specifically, the right end of the U-shaped pipe is located inside the space formed by the step portion (X). More specifically, the right end of the U-shaped connecting pipe (400) is located to the right of the left side surface of the front plate stack (50). In other words, in the left-right direction, the right end of the U-shaped connecting pipe (400) is located at the same position as the left side surface of the first plate (521) or to the right of that position.

[0089] The air conditioner indoor unit (30) includes a temperature sensor (70) for detecting the temperature of the refrigerant. The temperature sensor (70) detects the temperature of the refrigerant flowing through the heat transfer tube (42). The temperature sensor (70) is an example of a detection section (70).

[0090] As shown in Figures 12(a) and 12(b), the temperature sensor (70) is provided on the U-shaped connecting pipe (400), and the indoor heat exchanger (40) includes an attachment portion (90). The attachment portion (90) is a member for attaching the temperature sensor (70) to the U-shaped connecting pipe. The attachment portion (90) includes an attachment member (91) that houses the temperature sensor (70) and a brazing portion (92) that attaches the attachment member (91) to the surface of the U-shaped connecting pipe (400). The attachment member (91) is attached to the U-shaped connecting pipe (400) via the brazing portion (92).

[0091] The mounting member (91) has, for example, a substantially cylindrical shape and is configured to be able to accommodate a part of the temperature sensor (70) therein. The mounting member (91) is attached, for example, to a curved portion of the U-shaped connecting pipe (400). The brazing portion (92) is configured, for example, to extend linearly. The brazing portion (92) is formed, for example, by supplying brazing material between the U-shaped connecting pipe (400) and the mounting member (91) and heating the brazing material with the flame of a burner.

[0092] A sacrificial layer having a lower potential than the surface of the mounting member (91) is provided on a portion of the surface of the mounting member (91). The sacrificial layer is made of Zn, a Zn alloy, an Al alloy containing Zn, or the like, and is formed on the surface of the heat transfer tube (42) by, for example, thermal spraying. This sacrificial layer sacrificially protects the mounting member (91) from corrosion, thereby suppressing corrosion of the surface of the mounting member (91) for a long period of time.

[0093] The mounting member (91) and the piping such as the U-shaped connecting pipe (400) are made of the same type of metal such as aluminum A3003, etc. This makes it possible to prevent electrolytic corrosion of the mounting member (91) and the piping.

[0094] (5) Features (5-1) Feature 1 The front plate stack (50) of the plate stacks (50, 60) of the indoor heat exchanger (40) of this embodiment is disposed adjacent to the indoor heat exchanger body (B) in the right direction (first direction). The front plate stack (50) includes a front first plate portion (50A) having two front plates (52), and a front second plate portion (50B) having three front plates (52) different in shape from the front plates (52) of the front first plate portion (50A) and disposed on the surface of the front first plate portion (50A) opposite to the surface facing the heat exchanger body (B). A step portion (X) is formed on the peripheral edge of the surface of the front plate stack (50) facing the heat exchanger body (B), and the step portion (X) is formed by a front first plate portion (50A) and a front second plate portion (50B).

[0095] In this way, by providing the step portion (X) in the front plate stack (50), a space can be formed at a position opposite the step portion (X). By utilizing this space, for example, by arranging predetermined components in the space, the air conditioning indoor unit (30) can be made smaller.

[0096] (5-2) Feature 2 In this embodiment, the second to fourth plates (522 to 524) of the front plate stack (50) are thicker than the first plate (521) and the fifth plate (525), and the seventh to ninth plates (622 to 624) of the rear plate stack (60) are thicker than the sixth plate (621) and the tenth plate (625).

[0097] In this way, by increasing the thickness of the intermediate plates (522-524), it is possible to increase the cross-sectional area or inner diameter of the refrigerant flow paths (51, 61) formed in the plate stack (50, 60), thereby suppressing an increase in pressure loss of the refrigerant flowing through the refrigerant flow paths (51, 61).

[0098] (5-3) Feature 3 In this embodiment, the plate stack (50, 60) has a surface opposite to the surface facing the heat exchanger body (B) that is anticorrosive. This prevents electrolytic corrosion of the right side surface of the plate stack (50, 60) due to condensation or the like, thereby improving the durability of the indoor heat exchanger (40).

[0099] (5-4) Feature 4 When the front plate stack (50) is viewed from the left, the area of ​​the portion of the front second plate portion (50B) that is not overlapped by the front first plate portion (50A) is smaller than the area of ​​the portion that is overlapped by the front first plate portion (50A).

[0100] The overlapping portion of the front plate stack (50) between the front first plate portion (50A) and the front second plate portion (50B) is thicker than the portion consisting of only the front first plate portion (50A), and therefore a larger number of flow paths (51, 61) can be formed. This increases the flow rate of refrigerant through the heat transfer tubes (42) of the heat exchange section (B), thereby facilitating heat exchange. In this embodiment, by making the overlapping portion between the front first plate portion (50A) and the front second plate portion (50B) wider than the portion consisting of only the front first plate portion (50A), a sufficient number of flow paths can be ensured in the front plate stack (50), thereby facilitating heat exchange between air and refrigerant in the indoor heat exchanger (40).

[0101] (5-5) Feature 5: The front refrigerant flow path (51) includes a first flow path (51A) provided in the front first plate portion (50A) and a second flow path (51B) provided between the front first plate portion (50A) and the front second plate portion (50B). The second flow path (51B) is formed so as to intersect with the first flow path (51A).

[0102] By designing the front refrigerant flow path (51) so that the first flow path (51A) and the second flow path (51B) intersect, the variety of flow path patterns of the front refrigerant flow path (51) in the front plate stack (50) can be increased. Meanwhile, by providing a step (X) at a portion of the front plate stack (50) where only the first flow path (51A) is provided and the first flow path (51A) and the second flow path (51B) do not intersect, a space that can be effectively utilized can be formed. In other words, by providing such a step (X), it is possible to reduce unnecessary areas of one front plate (52) where the front refrigerant flow path (51) is not provided.

[0103] (5-6) Feature 6 The heat exchanger body (B) of this embodiment is provided with a U-shaped connecting pipe (400) that is disposed between the heat exchanger body (B) and the front plate stack (50) and connects the two heat transfer tubes (42). The U-shaped connecting pipe (400) is provided at a position facing the step portion (X) when viewed from the left (the opposite direction to the first direction).

[0104] Although the gap between the heat exchanger body (B) and the front plate stack (50) needs to be large enough to accommodate the U-shaped connecting pipe (400), in this embodiment, the connecting pipe (400) is arranged in the space formed by the step portion (X), so that the gap between the heat exchanger body (B) and the front plate stack (50) can be made relatively small, thereby enabling the indoor heat exchanger (40) to be made compact.

[0105] (5-7) Feature 7 In this embodiment, a temperature sensor (70) for detecting the temperature of the refrigerant flowing through the heat transfer pipe (42) is further provided, and the temperature sensor (70) is provided in the U-shaped connecting pipe (400). The space formed by the step portion (X) can be effectively utilized to provide the detection portion (70).

[0106] (6) Modifications A description will be given of a modification of the air conditioner indoor unit (30). The following describes configurations that differ from the air conditioner indoor unit (30) of the above embodiment.

[0107] (6-1) Modification 1 As shown in FIG. 13 , in an indoor heat exchanger (40) of Modification 1, a U-shaped connecting pipe (400) is connected to the front plate stack (50). Specifically, the U-shaped connecting pipe (400) is disposed in the first region (S1) of the front plate stack (50). Both ends of the U-shaped connecting pipe (400) extend rightward and connect to refrigerant flow paths (51, 61) formed in the front second plate portion (50B). In this manner, the refrigerant flowing through the refrigerant flow paths (51, 61) in the front plate stack (50) flows through the U-shaped connecting pipe (400) of Modification 1. By providing a temperature sensor (70) in the U-shaped connecting pipe (400), the temperature of the refrigerant flowing through the front plate stack (50) can be detected.

[0108] (6-2) Modification 2 The rear plate stack (60) of Modification 2 has the same configuration as the front plate stack (50) of the above embodiment. That is, the rear plate stack (60) has a rear first plate portion (60A) and a rear second plate portion (60B). The rear first plate portion (60A) and the rear second plate portion (60B) are examples of the first plate portions (50A, 60A) and the second plate portions (50B, 60B) of the present disclosure.

[0109] The rear plate stack (60) is an example of the plate stack (50, 60) of the present disclosure. The configurations of the rear first plate portion (60A) and the rear second plate portion (60B) are the same as the configurations of the front first plate portion (50A) and the front second plate portion (50B) of the front plate stack (50) of the above-described embodiment, respectively, and therefore description thereof will be omitted. When viewed from the left, the rear plate stack (60) is formed with a first region (S1) in which the rear second plate portion (60B) and the rear first plate portion (60A) do not overlap, and a second region (S2) in which the rear second plate portion (60B) and the rear first plate portion (60A) overlap.

[0110] In the indoor heat exchanger (40) of the second modification, the first internal pipe (38) and the second internal pipe (39) are arranged between the heat exchanger body (B) and the plate stack (50, 60). Specifically, the first internal pipe (38) is connected to the left side surface of the front plate stack (50). The second internal pipe (39) is connected to the left side surface of the rear plate stack (60). In this modification, the front relay portion (54) is arranged in the first region (S1) of the front plate stack (50), and the rear relay portion (64) is arranged in the first region (S1) of the rear plate stack (60). The first internal pipe (38) extends from the rear relay portion (64) to the left (heat exchanger body (B)) and then extends to the rear plate stack (60). The second internal pipe (39) extends from the rear relay portion (64) to the left (to the heat exchanger body (B)) and then extends to the front plate stack (50). In this manner, in this modification, even if the space between the heat exchanger body (B) and the plate stack (50, 60) is relatively narrow, the first internal pipe (38) and the second internal pipe (39) can be arranged by utilizing the space formed by the step portion (X).

[0111] (7) Other Embodiments The following configurations may be applied to the air conditioner indoor unit (30) of the above embodiment and the above modified example.

[0112] In the above embodiment, when the indoor heat exchanger (40) functions as a radiator, the indoor heat exchanger (40) may be configured so that refrigerant in the supercooled region flows through the U-shaped connecting pipe (400). The U-shaped connecting pipe (400) is disposed away from the front plate stack (50), thereby preventing heat exchange between the refrigerant in the supercooled region and the refrigerant flowing through the front plate stack (50).

[0113] When the rear plate assembly (60) has a rear first plate portion (60A) and a rear second plate portion as in the second modification, the U-shaped connecting pipe (400) may be disposed at a position facing the step portion (X) of the rear plate assembly (60). In this case, the U-shaped connecting pipe (400) may be connected to the rear heat exchanger body (B) or to the rear plate assembly (60). When the indoor heat exchanger (40) functions as an evaporator, the indoor heat exchanger (40) may be configured so that a refrigerant in a superheated region flows through the indoor heat exchanger (40). For example, the U-shaped connecting pipe (400) communicates with the first interconnecting pipe (12) via the gas end portion (65). In this way, the refrigerant in the superheated region flows through the U-shaped connecting pipe (400) located outside the plate stack (50, 60), thereby preventing the refrigerant flowing through the refrigerant flow path (51, 61) within the plate stack (50, 60) from exchanging heat with the refrigerant in the superheated region.

[0114] When the rear plate stack (60) has a rear first plate portion (60A) and a rear second plate portion (60B) as in the second modification, the gas end portion (65) may be connected to a rear refrigerant flow path (61) formed in a portion where the rear first plate portion (60A) and the rear second plate portion (60B) overlap. Specifically, the gas end portion (65) may be located in the second region (S2). In this manner, the refrigerant flowing into the rear plate stack (60) from the first connecting pipe (12) through the gas relay pipe (12a) passes through a relatively long refrigerant flow path (51, 61) extending in the stacking direction between the rear first plate portion (60A) and the rear second plate portion (60B). This makes it possible to suppress pressure loss of the compressed gas refrigerant.

[0115] The indoor heat exchanger (40) is arranged in an air passage (P) that communicates with an inlet (33) and an outlet (34) provided in the casing (31), and the step portion (X) may be formed downstream of the air flow in the plate stack (50, 60) when viewed from the right.

[0116] For example, in summer, when the indoor heat exchanger (40) functions as an evaporator, a temperature gradient is formed in the air passage (P) such that the temperature decreases from the inlet (33) to the outlet (34). Because the air temperature increases upstream in the air passage (P), the heat exchange load is greater in the upstream portion of the indoor heat exchanger (40) than in the downstream portion of the air flow. Therefore, by providing the step (X) in the downstream portion of the plate stack (50, 60) and thickening the upstream portion of the plate stack (50, 60), a sufficient number of refrigerant flow paths (51, 61) can be ensured in the upstream portion of the plate stack (50, 60). This increases the flow rate of refrigerant flowing to the upper portion of the heat exchanger body (B), thereby facilitating heat exchange between the refrigerant and air in the upper portion of the indoor heat exchanger (40). As a result, the heat exchange load at the upper part of the indoor heat exchanger (40) can be reduced, and the efficiency of heat exchange with the air flowing through the air passage (P) can be increased, so that the air temperature in the indoor space can be brought to the target temperature more quickly.

[0117] In the above modification, the rear plate stack (60) may be formed with rear refrigerant flow paths (61) corresponding to the first flow paths (51A) and the second flow paths (51B) of the front plate stack (50) of the above embodiment. In other words, the rear plate stack (50, 60) may be configured such that a plurality of rear refrigerant flow paths (61) intersect with each other.

[0118] In the above embodiment and modified examples, instead of using alloy plates having a sacrificial corrosion protection effect, anticorrosive or antirust paint may be applied to the plate stack (50, 60). In this case, the paint is an epoxy resin-based paint. The paint may be applied so that a coating film is formed on the front surface, including the right side surface (502) and the left side surface (501) of the plate stack (50, 60).

[0119] In the above embodiment and modified examples, the heat transfer tube (42), the plate stack (50, 60), the refrigerant piping (such as the connecting tube (53) and the U-shaped connecting tube (400)), the mounting member (91), and the detection portion of the temperature sensor (70) may be made of a copper alloy or stainless steel. The heat transfer tube (42), the U-shaped connecting tube (400), the mounting member (91), and the temperature sensor (70) are preferably made of the same metal. Furthermore, when the heat transfer tube (42) is made of a copper alloy, the plate stack (50, 60) and the refrigerant piping are also preferably made of a copper alloy.

[0120] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired. The terms "first," "second," etc., described above, are used to distinguish the terms to which these terms are attached, and do not limit the number or order of the terms.

[0121] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for indoor heat exchangers and air conditioning indoor units.

[0122] 12a Gas relay pipe (gas pipe) 30 Air conditioner indoor unit 40 Indoor heat exchanger 41 Fin 42 Heat transfer pipe 50, 60 Plate stack 50A, 60A First plate portion 50B, 60B Second plate portion 51, 61 Refrigerant flow path (flow path) 51A First flow path 51B Second flow path 52, 62 Plate 70 Temperature sensor (detection portion) 400 U-shaped connecting pipe (connecting pipe) 521 First plate (first end plate) 522~524 Intermediate plates 525 Second end plate (fifth plate) B Heat exchanger body (heat exchange portion) X Step portion

Claims

1. A heat exchanger (B) including a plurality of fins (41) and a plurality of heat transfer tubes (42) penetrating the plurality of fins (41); and a plate stack (50, 60) having a plurality of plates (52, 62) stacked in a first direction in which the heat transfer tubes (42) extend, with a flow path (51, 61) provided therein and communicating with the heat transfer tubes (42), the plate stack (50, 60) comprising: a first plate portion (50A, 60A) arranged adjacent to the heat exchanger (B) in the first direction and having one or more of the plates (52, 62); an indoor heat exchanger comprising: one or more plates (52, 62) having a shape different from the plates (52, 62) of the first plate portion (50A, 60A); and a second plate portion (50B, 60B) arranged on a surface of the first plate portion (50A, 60A) opposite to a surface facing the heat exchange portion (B); a step portion (X) is formed in a peripheral portion of a first surface (501, 601) of the plate stack (50, 60) facing the heat exchange portion (B), and the step portion (X) is formed by the first plate portion (50A, 60A) and the second plate portion (50B, 60B).

2. The plate stack (50, 60) is composed of three or more of the plates (52, 62), and when, in the plate stack (50, 60), the plate (52, 62) of the first plate portion (50A, 60A) closest to the heat exchange portion (B) is defined as a first end plate (521), the plate (52, 62) of the second plate portion (50B, 60B) farthest from the heat exchange portion (B) is defined as a second end plate (525), and the plate (52, 62) disposed between the first end plate (521) and the second end plate (525) is defined as an intermediate plate (522-524), the flow path (51, 61) is formed to pass through the intermediate plates (522-524, 622-624), The indoor heat exchanger according to claim 1, wherein the thickness of the intermediate plates (522-524) is greater than the thickness of the first end plate (521) and the second end plate (525).

3. The indoor heat exchanger according to claim 1 or 2, wherein at least a part of a first surface (501, 601) and a second surface (502, 602) opposite to the first surface (501, 601) of the plate stack (50, 60) is subjected to anti-corrosion treatment.

4. An indoor heat exchanger as described in any one of claims 1 to 3, wherein, when viewing the plate stack (50, 60) from the side opposite to the first direction, the area of ​​the portion of the second plate portion (50B, 60B) that does not overlap with the first plate portion (50A, 60A) is smaller than the area of ​​the portion where the first plate portions (50A, 60A) overlap.

5. The indoor heat exchanger according to any one of claims 1 to 4, wherein the flow path (51, 61) includes a first flow path (51A) provided in the first plate portion (50A, 60A) and a second flow path (51B) provided across the first plate portion (50A, 60A) and the second plate portion (50B, 60B), and the second flow path (51B) is formed so as to intersect with the first flow path (51A).

6. The indoor heat exchanger as claimed in any one of claims 1 to 5, wherein the heat exchange section (B) is provided with a U-shaped connecting pipe (400) that is disposed between the heat exchange section (B) and the plate stack (50, 60) and connects the two heat transfer tubes (42) together, and the connecting pipe (400) is provided at a position facing the step portion (X) when viewed from the first direction.

7. The indoor heat exchanger according to claim 6, further comprising a detection unit (70) for detecting a temperature of the refrigerant flowing through the heat transfer pipe (42), the detection unit (70) being provided on the connecting pipe (400).

8. The indoor heat exchanger according to claim 6 or 7, wherein a refrigerant in a superheated region flows through the connecting pipe (400) when the indoor heat exchanger functions as an evaporator, and a refrigerant in a subcooled region flows through the connecting pipe (400) when the indoor heat exchanger functions as a radiator.

9. An air-conditioning indoor unit comprising: an indoor heat exchanger according to any one of claims 1 to 8; and a gas pipe (12a) through which compressed refrigerant gas is transported to the indoor heat exchanger (40), wherein the gas pipe (12a) is connected to the flow path (51, 61) formed in a portion of the plate stack (50, 60) where the first plate portion (50A, 60A) and the second plate portion (50B, 60B) overlap.

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