Indoor heat exchanger, refrigeration cycle device, and air-conditioning indoor unit

Abstract

This indoor heat exchanger is provided with: heat exchange units (40A, 40B) having fins (41) and heat transfer tubes (42); plate structures (50, 60) to which the heat transfer tubes (42) are connected and in which refrigerant passages (51, 61) are formed; and a piping part that communicates with the heat transfer tubes (42) or the refrigerant passages (51, 61). A temperature sensor (70) for detecting the temperature of a refrigerant is provided in the piping part.

Description

Indoor heat exchanger, refrigeration cycle device and air conditioning indoor unit

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

[0002] Patent Document 1 discloses a heat exchanger. The heat exchanger described in Patent Document 1 includes a heat exchanger body and a refrigerant distributor. The heat exchanger body has refrigerant flow paths. The refrigerant distributor distributes and supplies refrigerant to multiple predetermined flow path portions in the heat exchanger body. The refrigerant distributor is provided with a plate-shaped distribution member and is composed of overlapping plate-shaped members including the plate-shaped distribution member. The plate-shaped distribution member is made of a center plate. The center plate has refrigerant branching flow path portions. The refrigerant branching flow path portions have a refrigerant throttling function to supply refrigerant at a predetermined flow rate to multiple predetermined flow path portions in the heat exchanger body.

[0003] Japanese Patent Application Laid-Open No. 2006-125652

[0004] In the indoor unit of an air conditioner, a thermistor for detecting refrigerant temperature may be provided in the indoor unit to measure the temperature of the heat exchanger or to detect the temperature of the refrigerant and control various components of the air conditioner (such as the compressor rotation speed) based on the detected refrigerant temperature.

[0005] The refrigerant distributor (plate structure) described in Patent Document 1 is provided, for example, to reduce the installation space for refrigerant piping in the indoor unit, thereby making the indoor unit more compact. However, this also limits the installation location of the thermistor, and depending on the installation location, the accuracy of the thermistor's detection of the refrigerant temperature may be reduced.

[0006] An object of the present disclosure is to enable the temperature of a refrigerant to be detected with high accuracy.

[0007] The first aspect is directed to an indoor heat exchanger, which includes a heat exchange section (40A, 40B) having fins (41) and heat transfer tubes (42), a plate structure (50, 60) to which the heat transfer tubes (42) are connected and in which a refrigerant passage (51, 61) is formed, and a piping section communicating with the heat transfer tubes (42) or the refrigerant passages (51, 61), and a temperature sensor (70) for detecting a temperature of the refrigerant is provided in the piping section.

[0008] In the first aspect, the temperature of the refrigerant can be detected with high accuracy.

[0009] In a second aspect, in the first aspect, the temperature sensor (70) is attached to the piping portion via an attachment member (91).

[0010] In the second embodiment, the temperature sensor (70) is mounted on the mounting member (91), thereby making it possible to attach the temperature sensor (70) to the piping portion.

[0011] In a third aspect, in the second aspect, the mounting member (91) and the portion of the piping where the temperature sensor (70) is mounted are made of the same type of metal.

[0012] In the third aspect, electrolytic corrosion of the mounting member (91) and the piping can be suppressed.

[0013] A fourth aspect is any one of the first to third aspects, wherein the heat exchange section (40A, 40B) includes a tube plate facing the plate structure (50, 60), and the distance between the tube plate and the plate structure (50, 60) is 35 mm or less.

[0014] In the fourth aspect, the heat exchanger can be formed compactly.

[0015] In a fifth aspect, in any one of the first to fourth aspects, the piping section includes a first piping section (81) that is not in communication with the refrigerant passages (51, 61) but is in communication with the two heat transfer tubes (42), and the temperature sensor (70) is provided in the first piping section (81).

[0016] In the fifth aspect, the temperature of the refrigerant flowing through the first piping section (81) can be detected.

[0017] In a sixth aspect, in any one of the first to fourth aspects, the piping section includes a second piping section (82) that is provided outside the plate structure (50, 60) and has both ends that communicate with the refrigerant passage (51, 61), and the temperature sensor (70) is provided in the second piping section (82).

[0018] In the sixth aspect, the temperature of the refrigerant flowing through the second piping section (82) can be detected.

[0019] A seventh aspect is any one of the first to fourth aspects, wherein the piping section includes a third piping section (83) provided between the heat exchange section (40A, 40B) and the plate structure (50, 60), and the temperature sensor (70) is provided in the third piping section (83).

[0020] In the seventh aspect, the temperature of the refrigerant flowing through the third piping section (83) can be detected.

[0021] An eighth aspect is any one of the first to fourth aspects, wherein the heat exchange section (40A, 40B) includes a first heat exchange section (40A) and a second heat exchange section (40B), the plate structure (50, 60) includes a first plate structure (50) to which a heat transfer tube (42) of the first heat exchange section (40A) is connected, and a second plate structure (60) to which a heat transfer tube (42) of the second heat exchange section (40B) is connected, the piping section includes a fourth piping section (84) communicating with a refrigerant passage (51, 61) formed in the first plate structure (50) and a refrigerant passage (51, 61) formed in the second plate structure (60), and the temperature sensor (70) is provided in the fourth piping section (84).

[0022] In the eighth aspect, the temperature of the refrigerant flowing through the fourth piping section (84) can be detected.

[0023] A ninth aspect is any one of the first to fourth aspects, wherein the heat exchange section (40A, 40B) includes a first heat exchange section (40A) and a second heat exchange section (40B), the plate structure (50, 60) includes a first plate structure (50) to which a heat transfer tube (42) of the first heat exchange section (40A) is connected, and a second plate structure (60) to which a heat transfer tube (42) of the second heat exchange section (40B) is connected, the piping section includes a fifth piping section (85) communicating with a refrigerant passage (51, 61) formed in the first plate structure (50) and the heat transfer tube (42) of the second heat exchange section (40B), and the temperature sensor (70) is provided in the fifth piping section (85).

[0024] In the ninth aspect, the temperature of the refrigerant flowing through the fifth piping section (85) can be detected.

[0025] A tenth aspect is any one of the first to fourth aspects, wherein the heat exchange sections (40A, 40B) include a first heat exchange section (40A) and a second heat exchange section (40B), the piping section includes a sixth piping section (86) communicating with a heat transfer tube (42) of the first heat exchange section (40A) and a heat transfer tube (42) of the second heat exchange section (40B), and the temperature sensor (70) is provided in the sixth piping section (86).

[0026] In the tenth aspect, the temperature of the refrigerant flowing through the sixth piping section (86) can be detected.

[0027] In an eleventh aspect, in any one of the first to tenth aspects, the refrigerant passage (111) of the plate structure (110) includes a branching section (111a) that branches the refrigerant to be flowed into the heat exchange section (100) and a merging section (111b) that merges the refrigerant flowing out of the heat exchange section (100), and the piping section is connected between the branching section (111a) and the merging section (111b).

[0028] In the eleventh aspect, the temperature of the refrigerant can be detected effectively.

[0029] In a twelfth aspect, in the eleventh aspect, the heat exchanger (40A, 40B) includes a first heat exchanger (40A) and a second heat exchanger (40B), and the refrigerant divided by the dividing portion (51a) flows into the first heat exchanger (40A), and the refrigerant flowing out of the second heat exchanger (40B) is merged by the merging portion (61b).

[0030] In the twelfth aspect, the temperature of the refrigerant can be detected effectively.

[0031] A thirteenth aspect is any one of the first to twelfth aspects, wherein a refrigerant in a gas-liquid two-phase state flows through the piping portion.

[0032] In the thirteenth aspect, the temperature of the refrigerant in a gas-liquid two-phase state can be detected.

[0033] A fourteenth aspect is directed to a refrigeration cycle apparatus, the refrigeration cycle apparatus including a refrigerant circuit (11) to which the indoor heat exchanger according to any one of the first to thirteenth aspects is connected.

[0034] A fifteenth aspect is directed to an air conditioning indoor unit, comprising: the indoor heat exchanger according to any one of the first to thirteenth aspects; and a casing (31) that houses the indoor heat exchanger.

[0035] 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. 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 portion of an indoor heat exchanger. FIG. 6 is a view of a plate structure as seen from the left side. FIG. 7 is a cross-sectional view illustrating a refrigerant passage of the plate structure. FIG. 8 is a partial perspective view of a front plate structure. FIG. 9 is a cross-sectional view along line IX-IX in FIG. 6. FIG. 10 is a view of a rear plate structure as seen from the right side. FIGS. 11(a) and 11(b) are schematic diagrams showing the configuration of an indoor heat exchanger. FIG. 12(a) is a schematic diagram showing a first pipe section in which a temperature sensor is provided. FIG. 12(b) is a perspective view showing a first sensor mounting section. FIG. 12(c) is a plan view showing the first sensor mounting section. FIG. 13 is a schematic diagram showing a second pipe section in which a temperature sensor is provided. FIG. 14 is a schematic diagram showing a third pipe section in which a temperature sensor is provided. Fig. 15(a) is a side view showing the second sensor mounting portion. Fig. 15(b) is a cross-sectional view showing the second sensor mounting portion. Fig. 16 is a schematic configuration diagram showing a fourth pipe section provided with a temperature sensor. Fig. 17 is a schematic configuration diagram showing a fifth pipe section provided with a temperature sensor. Fig. 18 is a schematic configuration diagram showing a sixth pipe section provided with a temperature sensor. Fig. 19 is a partial perspective view of a modified example of the front plate structure. Figs. 20(a) and 20(b) are schematic configuration diagrams showing the configuration of modified examples of the indoor heat exchanger.

[0036] 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.

[0037] (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.

[0038] 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.

[0039] 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.

[0040] 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).

[0041] 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.

[0042] 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).

[0043] (2) Air Conditioning Indoor Unit The indoor unit (30) serving as an indoor air conditioner will be described in detail with reference to Figures 2 to 4. The indoor unit (30) of this embodiment is a wall-mounted type that is 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 Figures 2 and 3, and the left-right directions are based on the case where the indoor casing (31) is viewed from the front.

[0044] 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).

[0045] 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).

[0046] 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).

[0047] (2-2) Filter The 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 indoor unit (30) may include a dust removal mechanism that removes the dust collected by the filter (35).

[0048] (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 structures (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).

[0049] (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).

[0050] (2-5) Flap The indoor unit (30) has a flap (36) that adjusts the direction of air blown out from the air outlet (34). The flap (36) adjusts the air direction in the vertical direction. The indoor unit (30) may have a plurality of flaps (36). The flap (36) may adjust the air direction in the horizontal direction.

[0051] (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).

[0052] (3-1) Indoor Heat Exchanger The indoor heat exchanger (40) shown in Figures 3 to 5 includes a heat exchanger body (B) and plate structures (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.

[0053] 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 direction of arrangement of the fins (41). The plate structures (50, 60) have therein refrigerant passages (51, 61) that communicate with the heat transfer tubes (42).

[0054] 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 forms an air passage. The material of the fins (41) is an aluminum alloy.

[0055] The heat transfer tubes (42) are straight tubes. The heat transfer tubes (42) are made of an aluminum alloy. A refrigerant passage 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 each heat transfer tube (42), i.e., a right end, protrudes to the right of the fin (41). One end of each heat transfer tube is connected to the plate structures (50, 60). Of the other ends of each heat transfer tube (42), i.e., left end portions, 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 and integrally.

[0056] The indoor heat exchanger (40) of this embodiment includes a heat exchange section. The heat exchange section has a front heat exchange section (40A) that is a first heat exchange section and a rear heat exchange section (40B) that 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 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.

[0057] The front heat exchange section (40A) includes a front main heat exchange section (43), a first auxiliary heat exchange section (44), a second auxiliary heat exchange section (45), and a tube plate (49).

[0058] The tube plate (49) is arranged so that its plate surface is aligned in the vertical and longitudinal directions, and is located to the right of the fins (41). The tube plate (49) faces the front plate structure (50). A plurality of heat transfer tubes (42) penetrate the tube plate (49). There is almost no gap between the tube plate (49) and each heat transfer tube (42), and the tube plate (49) supports the fins (41) and the heat transfer tubes (42). The U-shaped tubes (48), the first connecting pipe (12), and the front plate structure (50) are arranged on the right side of the tube plate (49), i.e., on the opposite side of the tube plate (49) from the fins (41). The distance (E) between the tube plate (49) and the front plate structure (50) is 35 mm or less. This allows the indoor heat exchanger (40) to be formed compactly.

[0059] 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.

[0060] The first auxiliary heat exchange section (44) is provided on the inlet side (front side) of the first front main heat exchange section (43a). The second auxiliary heat exchange section (45) is provided on the inlet side (front side) of the second front main heat exchange section (43b). The rear heat exchange section (40B) has a rear main heat exchange section (46), a third auxiliary heat exchange section (47), and a tube plate. The rear main heat exchange section (46) is disposed in the rear heat exchange section (40B) closer to the indoor fan (32). The third auxiliary heat exchange section (47) is provided on the inlet side (rear side) of the rear main heat exchange section (46). The tube plate of the rear heat exchange section (40B) faces the rear plate structure (60). The distance between the tube plate of the rear heat exchange section (40B) and the rear plate structure (60) is 35 mm or less.

[0061] As shown in Fig. 9, one end of the heat transfer tube (42) has a flared portion (42a). The flared portion (42a) has an expanded diameter portion (42b) whose diameter expands toward the right, and a cylindrical portion (42c) that extends toward the right from the right end of the expanded diameter portion (42b) with a constant diameter. As will be described in detail later, the flared portion (42a) is a portion that is connected to a connecting pipe (53, 63) of the plate structure (50, 60).

[0062] The plate structures (50, 60) are disposed to the right of the rightmost fin (41) and parallel to the fin (41). The plate structures (50, 60) are connected to one ends of the heat transfer tubes (42). As shown in FIG. 5 , the plate structures (50, 60) include a front plate structure (50) connected to the heat transfer tubes (42) of the front heat exchange section (40A) and a rear plate structure (60) connected to the heat transfer tubes (42) of the rear heat exchange section (40B). The front plate structure (50) is disposed so as to overlap the front heat exchange section (40A) in the axial direction of the heat transfer tubes (42). The rear plate structure (60) is disposed so as to overlap the rear heat exchange section (40B) in the axial direction of the heat transfer tubes (42).

[0063] (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 structures (50, 60). The indoor expansion valve (37) is connected to the front plate structure (50) via a first internal pipe (38) and is connected to the rear plate structure (60) via a second internal pipe (39). The first internal pipe (38) and the second internal pipe (39) are examples of refrigerant pipes that connect the refrigerant passage (51) of the front plate structure (50) and the refrigerant passage (61) of the rear plate structure (60).

[0064] Hereinafter, the first internal pipe (38) and the second internal pipe (39) may be collectively referred to as the internal pipes (38, 39).

[0065] One end of the gas relay pipe (12a) is connected to the rear plate structure (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 structure (50). The other end of the liquid relay pipe (13a) is connected to the second connecting pipe (13) via a joint.

[0066] (4) Plate Structure The plate structures (50, 60) will be described in detail with reference to FIGS. 5 to 10.

[0067] (4-1) Front Plate Structure The front plate structure (50) includes a front main body portion (52) having a refrigerant passage (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 passage (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 connecting piping (13) via the liquid relay pipe (13a).

[0068] As shown in FIGS. 5 and 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 structure (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 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 tubes (42) and the front connecting tube (53). In this embodiment, the material of each front plate is an aluminum alloy. 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.

[0069] The plurality of 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 pipe (42) of the front main heat exchange section (43).

[0070] The front connecting pipe (53) is fixed to the first front plate (521). The front connecting pipe (53) may be formed seamlessly and integrally with the first front plate (521).

[0071] As shown in Fig. 9, the tip end of the front connecting pipe (53) is inserted into the end of the corresponding heat transfer tube (42). In other words, the end of the heat transfer tube (42) is inserted onto the front connecting pipe (53). The front connecting pipe (53) is inserted into the flared portion (42a) of the corresponding heat transfer tube (42). The front connecting pipe (53) is inserted into the flared portion (42a) and joined to the cylindrical portion (42c) of the flared portion (42a) by burner brazing.

[0072] 5, the front relay portion (54) is a circular pipe. The front relay portion (54) is provided on the fifth front plate (525). The front relay portion (54) is joined to the front end of the first internal pipe (38) by brazing.

[0073] The liquid end portion (55) is a circular pipe and is provided on the fifth front plate (525). The liquid end portion (55) is joined to the end portion of the liquid relay pipe (13a) by brazing.

[0074] (4-2) Rear Plate Structure The rear plate structure (60) includes a rear main body portion (62) having a refrigerant passage (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 passage (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 connecting piping (12) via the gas relay pipe (12a).

[0075] The rear body portion (62) has basically the same configuration as the front body portion (52), except for 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 passages (61). 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 structure (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 tubes (42) and the rear connecting pipe (63). In this embodiment, the rear plates are made of an aluminum alloy. The five rear plates are joined to each other by furnace brazing. Note that the number of rear plates is just an example, and the number of rear plates may be four or less or six or more. The number of front plates may be different from the number of rear plates. Hereinafter, when it is not necessary to distinguish between the respective rear plates, they will simply be referred to as rear plates.

[0076] The rear connecting pipe (63) is a circular pipe. The second connecting pipe (63) is made of an aluminum alloy. As shown in Fig. 10, the rear connecting pipes (63) are arranged in a manner corresponding to the arrangement of the heat transfer pipes (42) of the rear heat exchange section (40B).

[0077] In the rear plate structure (60), the rear connecting pipe (63) is inserted into the end of the heat transfer tube (42). The rear connecting pipe (63) is inserted into the flared portion (42a) of the corresponding heat transfer tube (42). The rear connecting pipe (63) is inserted into the flared portion (42a) and joined to the cylindrical portion (42c) of the flared portion (42a) by burner brazing.

[0078] 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). The rear relay portion (64) is joined to the end of the second internal pipe (39) by brazing.

[0079] The gas end portion (65) is a circular pipe and is provided on the fifth rear plate (625). The gas end portion (65) is joined to the end portion of the gas relay pipe (12a) by brazing.

[0080] (5) Operation The air conditioner (10) performs cooling operation, heating operation, and dehumidifying operation.

[0081] (5-1) Cooling Operation In 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 Figure 1), appropriately adjusts the opening of the outdoor expansion valve (23), and fully opens the indoor expansion valve (37).

[0082] During 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.

[0083] 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 outlet (34).

[0084] (5-2) Heating Operation In heating operation, the controller of the air conditioner (10) operates the compressor (21), the outdoor fan (25), and the indoor fan (32), places the four-way switching valve (24) in the second state (the state shown by the dashed line in FIG. 1), adjusts the opening of the outdoor expansion valve (23) to a predetermined opening, and fully opens the indoor expansion valve (37).

[0085] During 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.

[0086] 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 outlet (34).

[0087] (5-3) Dehumidifying Operation In the dehumidifying 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 Figure 1), and appropriately adjusts the apertures of the outdoor expansion valve (23) and the indoor expansion valve (37).

[0088] During dehumidification operation, the refrigerant circuit (11) performs a refrigeration cycle in which the outdoor heat exchanger (22) and the front heat exchange section (40A) of the indoor heat exchanger (40) function as condensers (radiators), and the rear heat exchange section (40B) of the indoor heat exchanger (40) functions as an evaporator.

[0089] The indoor unit (30) draws room air from the indoor space (I) into the air passage (P) through the air inlet (33). The rear heat exchanger (40B) cools the air in the air passage (P) to a temperature below the dew point. The front heat exchanger (40A) heats the air in the air passage (P). The air passing through both the rear heat exchanger and the front heat exchanger mixes in the air passage (P) to produce low-humidity air. The air dehumidified in this manner is supplied to the indoor space (I) through the air outlet (34).

[0090] (6) Refrigerant Passage Structure of Indoor Unit As shown in Figures 11(a) and 11(b), the refrigerant passage (51) of the front plate structure (50) includes a first branch portion (51a) and a first junction portion (51b). The first branch portion (51a) is connected to the liquid relay pipe (13a). The front connecting pipes (53) include a plurality of first front connecting pipes (531) and a plurality of second front connecting pipes (532). The first branch portion (51a) is connected to each of the first front connecting pipes (531).

[0091] The heat transfer tubes (42) of the front heat exchange section (40A) include a plurality of first front heat transfer tubes (421) and a plurality of second front heat transfer tubes (422). The plurality of first front heat transfer tubes (421) and the plurality of second front heat transfer tubes (422) are connected to each other by U-shaped tubes (48) or the like. The plurality of first front heat transfer tubes (421) correspond to the plurality of first front connecting tubes (531) respectively, and are connected to the corresponding first front connecting tubes (531) for each of the first front heat transfer tubes (421). The plurality of second front heat transfer tubes (422) correspond to the plurality of second front connecting tubes (532) respectively, and are connected to the corresponding second front connecting tubes (532) for each of the second front heat transfer tubes (422).

[0092] The first junction (51b) is connected to each of the plurality of second front connecting pipes (532). The first junction (51b) is connected to the internal pipes (38, 39) (specifically, the first internal pipe (38)).

[0093] The refrigerant passage (61) of the rear plate structure (60) includes a second branch portion (61a) and a second junction portion (61b). The second branch portion (61a) is connected to the internal pipes (38, 39) (specifically, the second internal pipe (39)). The front connecting pipes (53) include a plurality of first rear connecting pipes (631) and a plurality of second rear connecting pipes (632).

[0094] The heat transfer tubes (42) of the rear heat exchange section (40B) include a plurality of first rear heat transfer tubes (423) and a plurality of second rear heat transfer tubes (424). The plurality of first rear heat transfer tubes (423) and the plurality of second rear heat transfer tubes (424) are connected to each other by U-shaped tubes (48) or the like. The plurality of first rear heat transfer tubes (423) correspond to the plurality of first rear connecting tubes (631) respectively, and are connected to the corresponding first rear connecting tubes (631) for each of the first rear heat transfer tubes (423). The plurality of second rear heat transfer tubes (424) correspond to the plurality of second rear connecting tubes (632) respectively, and are connected to the corresponding second rear connecting tubes (632) for each of the second rear heat transfer tubes (424).

[0095] The second junction (61b) is connected to each of the plurality of second rear connecting pipes (632). The second junction (61b) is connected to the gas relay pipe (12a).

[0096] During cooling operation and dehumidification operation, the refrigerant flows through the liquid relay pipe (13a), the first branch section (51a), the plurality of first front connecting pipes (531), the front heat exchange section (40A) (the plurality of first front heat transfer pipes (421) and the plurality of second front heat transfer pipes (422)), the plurality of second front connecting pipes (532), the first junction section (51b), the internal pipes (38, 39), the second branch section (61a), the plurality of first rear connecting pipes (631), the rear heat exchange section (40B) (the plurality of first rear heat transfer pipes (423) and the plurality of second rear heat transfer pipes (424)), the plurality of second rear connecting pipes (632), the second junction section (61b), and the gas relay pipe (12a), in this order. At this time, the indoor heat exchanger (40) functions as an evaporator, and the refrigerant changes from a liquid state to a gas state in the front heat exchange section (40A) and the rear heat exchange section (40B) by pumping up heat.

[0097] During heating operation, the refrigerant flows in the opposite direction to that during cooling and dehumidifying operation. At this time, the indoor heat exchanger (40) functions as a condenser, and the refrigerant changes from a gaseous state to a liquid state in the front heat exchange section (40A) and the rear heat exchange section (40B) by releasing heat.

[0098] (7) Temperature Sensor Installation Structure The indoor heat exchanger (40) includes a temperature sensor (70). The temperature sensor (70) detects the temperature of the refrigerant. The temperature sensor (70) includes a thermistor.

[0099] The temperature sensor (70) is provided in the piping section. The piping section is a tubular member. The piping section is in communication with at least one of the heat transfer pipe (42) and the refrigerant passages (51, 61). The piping section is connected between the first branch section (51a) and the second junction section (61b). That is, the piping section is provided so that the refrigerant flowing from one of the first branch section (51a) and the second junction section (61b) to the other passes through the piping section. Examples of the piping section in this case include the following first piping section (81) (see FIG. 12(a)), second piping section (82) (see FIG. 13), third piping section (83) (see FIG. 14), fourth piping section (84) (see FIG. 16), fifth piping section (85) (see FIG. 17), and sixth piping section (86) (see FIG. 18).

[0100] The piping section is preferably connected between the front heat exchange section (40A) and the rear heat exchange section (40B). That is, the piping section is preferably provided so that the refrigerant flowing from one of the front heat exchange section (40A) and the rear heat exchange section (40B) to the other passes through the piping section on its way. Examples of the piping section in this case include the following fourth piping section (84) (see FIG. 16 ), fifth piping section (85) (see FIG. 17 ), and sixth piping section (86) (see FIG. 18 ). A refrigerant in a gas-liquid two-phase state, in which gas refrigerant and liquid refrigerant are mixed, flows through the piping section.

[0101] (7-1) First Piping Section As shown in Figures 12(a) to 12(c), the piping section includes a first piping section (81). The temperature sensor (70) may be provided in the first piping section (81).

[0102] The first piping section (81) does not communicate with the refrigerant passages (51, 61) of the plate structures (50, 60) but communicates with two heat transfer tubes (42) of the front heat exchange section (40A). The first piping section (81) has a U-shape. One end of the first piping section (81) communicates with one of the heat transfer tubes (42) of the front heat exchange section (40A), and the other end of the first piping section (81) communicates with another of the heat transfer tubes (42) of the front heat exchange section (40A). The refrigerant flowing through one of the heat transfer tubes (42) of the front heat exchange section (40A) is sent to the other heat transfer tube (42) through the first piping section (81).

[0103] The first piping section (81) may have a structure in which it communicates with the two heat transfer tubes (42) of the rear heat exchange section (40B) without communicating with the refrigerant passages (51, 61) of the plate structures (50, 60).

[0104] A first example of a configuration for providing the temperature sensor (70) in the piping section will be described below. Here, a configuration for providing the temperature sensor (70) in the first piping section (81) will be described.

[0105] As shown in Figures 12(a) to 12(c), the indoor heat exchanger (40) includes a first sensor mounting portion (90). The first sensor mounting portion (90) is a member for mounting the temperature sensor (70) to a piping portion such as the first piping portion (81). The first sensor mounting portion (90) includes a mounting member (91) that houses the temperature sensor (70) and a brazing portion (92) that mounts the mounting member (91) to the surface of the first piping portion (81). The mounting member (91) is mounted to the first piping portion (81) via the brazing portion (92).

[0106] 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 first piping section (81). The brazed portion (92) is configured, for example, to extend linearly. The brazed portion (92) is formed, for example, by supplying brazing material between the first piping section (81) and the mounting member (91) and heating the brazed portion (92) with the flame of a burner.

[0107] 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.

[0108] The first piping section (81), the temperature sensor (70), and the mounting member (91) are all made of materials with the same potential, and have a higher potential than the sacrificial layer and a lower potential than the brazed portion (92). Furthermore, at least a portion of the brazed portion (92), which constitutes a part of the mounting member (91), is attached to a surface of the first piping section (81) on which no sacrificial layer is provided. Because at least a portion of the mounting member (91) is attached to a portion of the surface of the first piping section (81) on which no sacrificial layer is provided, even if the sacrificial layer corrodes, the temperature sensor (70) can be prevented from falling off from the aluminum first piping section (81).

[0109] The mounting member (91) and the piping portion such as the first piping portion (81) 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 portion.

[0110] (7-2) Second Piping Section As shown in Fig. 13, the piping section includes a second piping section (82). The temperature sensor (70) may be provided in the second piping section (82).

[0111] The second piping section (82) is provided outside the first plate structure (50), and both ends thereof communicate with the refrigerant passages (51) of the first plate structure (50). Both ends of the second piping section (82) communicate with, for example, the refrigerant passages (51) forming the first junction (51b) (see FIG. 11(b)). The refrigerant flowing through the refrigerant passages (51) is sent from one end of the second piping section (82) to the second piping section (82), and then returns to the refrigerant passages (51) from the other end of the second piping section (82).

[0112] The second piping portion (82) may be provided outside the second plate structure (60), and both ends thereof may be in communication with the refrigerant passages (61) of the second plate structure (60). In this case, both ends of the second piping portion (82) are in communication with, for example, the refrigerant passages (61) that form the second branch portion (61a).

[0113] (7-3) Third Piping Section As shown in Fig. 14, the piping section includes a third piping section (83). The temperature sensor (70) may be provided in the third piping section (83).

[0114] The third piping section (83) is provided between the front heat exchange section (40A) and the front plate structure (50). The third piping section (83) is in communication with the heat transfer tubes (42) of the front heat exchange section (40A) and the refrigerant passages (51) of the front plate structure (50). In this embodiment, the third piping section (83) is the front connecting pipe (53). Note that the third piping section (83) may be a pipe that is integrally formed with the heat transfer tubes (42) of the front heat exchange section (40A), extends from the heat transfer tubes (42) of the front heat exchange section (40A) toward the front plate structure (50), and is connected to the refrigerant passages (51) of the front plate structure (50).

[0115] The third piping section (83) may be provided between the rear heat exchange section (40B) and the rear plate structure (60). In this case, the third piping section (83) communicates with the heat transfer tubes (42) of the rear heat exchange section (40B) and the refrigerant passages (61) of the rear plate structure (60). In this case, the third piping section (83) is the rear connecting pipe (63). Note that the third piping section (83) may be a pipe that is integrally formed with the heat transfer tubes (42) of the rear heat exchange section (40B), extends from the heat transfer tubes (42) of the rear heat exchange section (40B) toward the rear plate structure (60), and is connected to the refrigerant passages (61) of the rear plate structure (60).

[0116] A second example of a configuration for providing the temperature sensor (70) in the piping section will be described below, in which a configuration for providing the temperature sensor (70) in the third piping section (83) will be described.

[0117] As shown in Figures 15(a) and 15(b), the indoor heat exchanger (40) includes a second sensor mounting portion (95). The second sensor mounting portion (95) is a clip-shaped member. The second sensor mounting portion (95) is made of, for example, stainless steel. The third piping portion (83) and the temperature sensor (70) are sandwiched between the second sensor mounting portion (95), thereby attaching the temperature sensor (70) to the third piping portion (83).

[0118] The mounting member (91) (see FIG. 12(a)) and the second sensor mounting portion (95) (see FIG. 15(a)) may support the temperature sensor (70) such that the longitudinal direction of the temperature sensor (70) is inclined relative to the horizontal direction. This makes it possible to prevent water from accumulating in the temperature sensor (70), thereby preventing corrosion of the temperature sensor (70).

[0119] (7-4) Fourth Piping Section As shown in Fig. 16, the piping section includes a fourth piping section (84). The temperature sensor (70) may be provided in the fourth piping section (84).

[0120] The fourth piping portion (84) communicates with the refrigerant passages (51) formed in the front plate structure (50) and the refrigerant passages (61) formed in the rear plate structure (60). In this embodiment, the third piping portion (83) is the first internal pipe (38) or the second internal pipe (39). In Fig. 16, the indoor expansion valves (37) provided in the internal pipes (38, 39) are omitted. The first internal pipe (38) or the second internal pipe (39) serving as the third piping portion (83) may have a portion overlapping with the front plate structure (50) in a front view (from the front of the indoor unit (30)) (see Fig. 5).

[0121] (7-5) Fifth Piping Section As shown in FIG. 17 , the piping section includes a fifth piping section (85). The fifth piping section (85) communicates with the refrigerant passages (51) formed in the front plate structure (50) and the heat transfer tubes (42) of the rear heat exchange section (40B). The temperature sensor (70) may be provided in the fifth piping section (85). The fifth piping section (85) may be a pipe that communicates with the refrigerant passages (61) formed in the rear plate structure (60) and the heat transfer tubes (42) of the front heat exchange section (40A). In FIG. 17 , the indoor expansion valve (37) provided in the fifth piping section (85) is omitted.

[0122] (7-6) Sixth Piping Section As shown in Fig. 18 , the piping section includes a sixth piping section (86). The sixth piping section (86) is in fluid communication with the heat transfer tubes (42) of the front heat exchange section (40A) and the heat transfer tubes (42) of the rear heat exchange section (40B). The temperature sensor (70) may be provided in the sixth piping section (86). In Fig. 18 , the indoor expansion valve (37) provided in the sixth piping section (86) is omitted.

[0123] (8) Advantages of the Embodiment If the temperature sensor (70) were provided on the plate structure (50, 60), the refrigerant flowing through the refrigerant passages (51, 61) of the plate structure (50, 60) would undergo thermal diffusion due to thermal conduction in the plates constituting the plate structure (50, 60), which could result in a decrease in the accuracy of refrigerant detection. In contrast, in the present embodiment, the temperature sensor (70) is provided on the heat transfer tube (42) or on a piping section (any of the first piping section (81) to the sixth piping section (86)) communicating with the refrigerant passages (51, 61). This reduces the thermal diffusion of the refrigerant in the piping section compared to the plate structure (50, 60), thereby enabling the refrigerant temperature to be detected with high accuracy.

[0124] Furthermore, by providing a temperature sensor (70) in the piping section through which the refrigerant in a gas-liquid two-phase state flows and configuring the temperature sensor (70) to detect the temperature of the refrigerant in the gas-liquid two-phase state, the temperature of the refrigerant in the gas-liquid two-phase state is more stable than the temperature of the refrigerant in a single-phase state (gas or liquid state), and therefore the temperature of the refrigerant can be detected with high accuracy.

[0125] (9) Modifications The indoor heat exchanger (40) described above may have the following modified configurations: Differences from the above embodiment will be described below.

[0126] In a modified example, as shown in Fig. 19, the front plate structure (50) of the modified example is formed of a single plate. As in the above-described embodiment, the front plate structure (50) of the modified example has a refrigerant passage formed therein. The front plate structure (50) of the modified example is manufactured by sintering metal powder using a 3D printer. The rear plate structure (60) may also be formed of a single plate.

[0127] (10) Other Embodiments The indoor heat exchanger (40) does not have to be of the fin-and-tube type, and may be of, for example, a corrugated type in which corrugated fins are arranged between adjacent heat transfer tubes.

[0128] As shown in Figures 20(a) and 20(b), the indoor heat exchanger (40) may have a single heat exchange section, without including a front heat exchange section (40A) and a 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. In this case, the indoor heat exchanger (40) includes one heat exchange section (100) and one plate structure (110). The refrigerant passage (111) of the plate structure (110) includes a branch section (111a) and a junction section (111b). The heat transfer tube (101) of the heat exchange section (100) includes a plurality of first heat transfer tubes (101a) and a plurality of second heat transfer tubes (101b). The plurality of first heat transfer tubes (101a) and the plurality of second heat transfer tubes (101b) are connected to one another by U-shaped tubes (48). The branching section (111a) is connected to the liquid relay pipe (13a). The branching section (111a) is connected to the plurality of first heat transfer tubes (101a) via a plurality of connecting pipes (112). The junction section (111b) is connected to the gas relay pipe (12a). The junction section (111b) is connected to the plurality of second heat transfer tubes (101b) via a plurality of connecting pipes (113). The piping section in which the temperature sensor (70) is provided is connected between the branching section (111a) and the junction section (111b). In other words, the piping section is provided so that the refrigerant flowing from one of the branching section (111a) and the junction section (111b) to the other passes through the piping section midway. In this case, examples of the piping section include the above-mentioned first piping section (81) (see FIG. 12(a)), second piping section (82) (see FIG. 13), third piping section (83) (see FIG. 14), etc.

[0129] 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 structures (50, 60) are preferably made of a copper alloy as well. When the heat transfer tubes (42) are made of a copper alloy, the first piping section (81) and the mounting member (91) are preferably made of a copper alloy as well.

[0130] The connecting pipes (53, 63) may be made of a copper alloy or stainless steel (SUS) instead of aluminum. In this case, the plate structures (50, 60) are preferably made of the same material as the connecting pipes (53, 63).

[0131] When a gas-liquid two-phase refrigerant flows through the refrigerant passages (51, 61, 111) of the plate structure (50, 60, 110), a temperature sensor (70) may be attached (provided) to the plate structure (50, 60, 110).

[0132] Although the embodiments and modifications have been described above, it will be understood that various modifications in 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 combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired.

[0133] The above-mentioned descriptions such as "first," "second," "third," etc. are used to distinguish the words to which these descriptions are attached, and do not limit the number or order of the words.

[0134] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for indoor heat exchangers, refrigeration cycle devices, and air conditioner indoor units.

[0135] REFRIGERATION PATH 70 TEMPERATURE SENSOR 80 REFRIGERATED AIR SUPPLY 81 REFRIGERATED AIR SUPPLY 82 REFRIGERATED AIR SUPPLY 83 REFRIGERATED AIR SUPPLY 84 REFRIGERATED AIR SUPPLY 85 REFRIGERATED AIR SUPPLY 86 REFRIGERATED AIR SUPPLY 87 REFRIGERATED AIR SUPPLY 88 REFRIGERATED AIR SUPPLY 89 REFRIGERATED AIR SUPPLY 89 REFRIGERATED AIR SUPPLY 80 REFRIGERATED AIR SUPPLY 81 REFRIGERATED AIR SUPPLY 82 REFRIGERATED AIR SUPPLY 84 REFRIGERATED AIR SUPPLY 85 REFRIGERATED AIR SUPPLY 86 REFRIGERATED AIR SUPPLY 87 REFRIGERATED AIR SUPPLY 88 REFRIGERATED AIR SUPPLY 89 ...

Claims

1. An indoor heat exchanger comprising: a heat exchange section (40A, 40B) having fins (41) and a heat transfer tube (42); a plate structure (50, 60) to which the heat transfer tube (42) is connected and to which a refrigerant passage (51, 61) is formed; and a piping section communicating with the heat transfer tube (42) or the refrigerant passage (51, 61), wherein a temperature sensor (70) for detecting a temperature of the refrigerant is provided in the piping section.

2. The indoor heat exchanger according to claim 1, wherein the temperature sensor (70) is attached to the piping portion via a mounting member (91).

3. The indoor heat exchanger according to claim 2, wherein the mounting member (91) and the portion of the piping where the temperature sensor (70) is attached are made of the same type of metal.

4. An indoor heat exchanger as claimed in any one of claims 1 to 3, wherein the heat exchange portion (40A, 40B) includes a tube plate (49) facing the plate structure (50, 60), and a spacing dimension between the tube plate and the plate structure (50, 60) is 35 mm or less.

5. An indoor heat exchanger as described in any one of claims 1 to 4, wherein the piping section includes a first piping section (81) that communicates with two of the heat transfer tubes (42) without communicating with the refrigerant passages (51, 61), and the temperature sensor (70) is provided in the first piping section (81).

6. An indoor heat exchanger as described in any one of claims 1 to 4, wherein the piping section includes a second piping section (82) provided outside the plate structure (50, 60) and communicating at both ends with the refrigerant passage (51, 61), and the temperature sensor (70) is provided in the second piping section (82).

7. An indoor heat exchanger as described in any one of claims 1 to 4, wherein the piping section includes a third piping section (83) provided between the heat exchange section (40A, 40B) and the plate structure (50, 60), and the temperature sensor (70) is provided in the third piping section (83).

8. The indoor heat exchanger according to any one of claims 1 to 4, wherein the heat exchange section (40A, 40B) includes a first heat exchange section (40A) and a second heat exchange section (40B); the plate structure (50, 60) includes a first plate structure (50) to which a heat transfer tube (42) of the first heat exchange section (40A) is connected, and a second plate structure (60) to which a heat transfer tube (42) of the second heat exchange section (40B) is connected; the piping section includes a fourth piping section (84) communicating with a refrigerant passage (51, 61) formed in the first plate structure (50) and a refrigerant passage (51, 61) formed in the second plate structure (60); and the temperature sensor (70) is provided in the fourth piping section (84).

9. The indoor heat exchanger according to any one of claims 1 to 4, wherein the heat exchange section (40A, 40B) includes a first heat exchange section (40A) and a second heat exchange section (40B); the plate structure (50, 60) includes a first plate structure (50) to which a heat transfer tube (42) of the first heat exchange section (40A) is connected, and a second plate structure (60) to which a heat transfer tube (42) of the second heat exchange section (40B) is connected; the piping section includes a fifth piping section (85) communicating with a refrigerant passage (51, 61) formed in the first plate structure (50) and the heat transfer tube (42) of the second heat exchange section (40B); and the temperature sensor (70) is provided in the fifth piping section (85).

10. An indoor heat exchanger as described in any one of claims 1 to 4, wherein the heat exchange sections (40A, 40B) include a first heat exchange section (40A) and a second heat exchange section (40B), the piping section includes a sixth piping section (86) communicating with a heat transfer tube (42) of the first heat exchange section (40A) and a heat transfer tube (42) of the second heat exchange section (40B), and the temperature sensor (70) is provided in the sixth piping section (86).

11. An indoor heat exchanger as described in any one of claims 1 to 10, wherein the refrigerant passage (111) of the plate structure (110) includes a branching section (111a) that branches the refrigerant to be flowed into the heat exchange section (100) and a junction section (111b) that joins the refrigerant flowing out from the heat exchange section (100), and the piping section is connected between the branching section (111a) and the junction section (111b).

12. The indoor heat exchanger as described in claim 11, wherein the heat exchange sections (40A, 40B) include a first heat exchange section (40A) and a second heat exchange section (40B), and the refrigerant branched by the branch section (51a) flows into the first heat exchange section (40A), and the refrigerant flowing out from the second heat exchange section (40B) is joined by the junction section (61b).

13. An indoor heat exchanger according to any one of claims 1 to 12, wherein a refrigerant in a gas-liquid two-phase state flows through the piping section.

14. A refrigeration cycle device comprising a refrigerant circuit (11) to which the indoor heat exchanger according to any one of claims 1 to 13 is connected.

15. An air-conditioning indoor unit comprising: an indoor heat exchanger according to any one of claims 1 to 13; and a casing (31) that houses the indoor heat exchanger.

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