EP4597021A1

EP4597021A1 - Indoor heat exchanger and air conditioner

Info

Publication number: EP4597021A1
Application number: EP23872450.4A
Authority: EP
Inventors: Shutaro YAMAMOTO; Hiroyuki Nakano; Yoshiyuki Matsumoto; Shota AGO
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2022-09-30
Filing date: 2023-09-27
Publication date: 2025-08-06
Also published as: EP4597021A4; CN119654534B; JP2024052597A; CN119654534A; JP7502704B2; WO2024071228A1

Abstract

An object of the present disclosure is to suppress the increase in size of a plate stacked body.In an indoor heat exchanger, some (heat transfer pipe 121a, heat transfer pipe 122a) of heat transfer pipes 12 are connected via refrigerant passages 22m of U-bend pipes 22 or refrigerant passages of communication pipes, and other heat transfer pipes 12 are connected via a refrigerant passage 30m of a plate stacked body 30.

Description

[Technical Field]

The present disclosure relates to an indoor heat exchanger and an air conditioner including this indoor heat exchanger.

[Background]

Patent Literature 1 discloses an air-conditioning indoor unit used for an air conditioner. In this air-conditioning indoor unit, in order to save space, a plate-shaped distribution member formed of stacked plates is connected to heat transfer pipes of a heat exchanger main body.

[Citation List]

[Patent Literatures]

[Patent Literature 1] Japanese Laid-Open Patent Publication No. 2006-125652

[Summary of the Invention]

[Technical Problem]

In Patent Literature 1, all heat transfer pipes of the heat exchanger main body are connected to the plate-shaped distribution member. In this case, the size of the plate-shaped distribution member (equivalent to a "plate stacked body" of the present disclosure) is increased depending on the structure of a refrigerant passage formed in the plate-shaped distribution member.
An object of the present disclosure is to provide (i) an indoor heat exchanger making it possible to suppress the increase in size of a plate stacked body (ii) an air conditioner including this indoor heat exchanger.

[Solution to Problem]

According to a first aspect of the present disclosure, an indoor heat exchanger comprises: a heat exchanging portion including a fin and heat transfer pipes penetrating the fin; a refrigerant pipe in which a first refrigerant passage is formed; and a plate stacked body which includes plates stacked in a stacked direction and in which a second refrigerant passage is formed, the heat transfer pipes including a first heat transfer pipe, a second heat transfer pipe, a third heat transfer pipe, and a fourth heat transfer pipe, the first heat transfer pipe being connected to the second heat transfer pipe via the first refrigerant passage, and the third heat transfer pipe being connected to the fourth heat transfer pipe via the second refrigerant passage.
In the first aspect of the present disclosure, not of the first to fourth heat transfer pipes are connected via the second refrigerant passage of the plate stacked body. The first and second heat transfer pipes are connected via the first refrigerant passage of the refrigerant pipe, and the third and fourth heat transfer pipes are connected via the second refrigerant passage of the plate stacked body. This suppresses the increase in size of the plate stacked body.
According to a second aspect of the present disclosure, the indoor heat exchanger of the first aspect may be arranged such that the refrigerant pipe is a U-bend pipe, and the first heat transfer pipe and the second heat transfer pipe are adjacent to each other. This provides a simple structure.
According to a third aspect of the present disclosure, the indoor heat exchanger of the first or second aspect may be arranged such that the refrigerant pipe is a U-bend pipe, the temperature of a first refrigerant flowing in the first refrigerant passage is a first temperature, and the temperature of a second refrigerant flowing in the second refrigerant passage is a second temperature, and a difference between the first temperature and the second temperature is larger than a predetermined value. If the first refrigerant and the second refrigerant flow in the second refrigerant passage while a temperature difference between the first refrigerant and the second refrigerant is larger than the predetermined value, heat exchange between the first refrigerant and the second refrigerant may occur in the plate stacked body so that a significant heat loss occurs. In this aspect of the present disclosure, the first refrigerant flows in the first refrigerant passage of the U-bend pipe, and the second refrigerant flows in the second refrigerant passage of the plate stacked body. With this arrangement, the heat exchange between the first refrigerant and the second refrigerant does not occur in the plate stacked body, and the significant heat loss does not occur.
According to a fourth aspect of the present disclosure, the indoor heat exchanger of the third aspect may be arranged such that the first refrigerant is a liquid-phase refrigerant or a gas-phase refrigerant, and the second refrigerant is a gas-liquid two phase refrigerant. The temperature of the liquid-phase refrigerant is lower than that of the gas-liquid two phase refrigerant, and the temperature of the gas-phase refrigerant is higher than that of the gas-liquid two phase refrigerant. In this aspect of the present disclosure, a structure in which the heat exchange between the first refrigerant and the second refrigerant does not occur in the plate stacked body is effectively realized.
According to a fifth aspect of the present disclosure, the indoor heat exchanger of any one of the first to fourth aspects may be arranged such that a first distance from end faces of the heat transfer pipes to a surface of the plate stacked body in the stacked direction is shorter than a second distance from the end faces of the heat transfer pipes to a part of the refrigerant pipe in the stacked direction, the surface of the plate stacked body being a surface closest to the end faces of the heat transfer pipes, and the part of the refrigerant pipe being a part furthest from the end faces of the heat transfer pipes. In this case, space is utilized by arranging the plate stacked body so as to overlap with the refrigerant pipe in side view.
According to a sixth aspect of the present disclosure, the indoor heat exchanger of the fifth aspect may be arranged such that the refrigerant pipe is provided at a position corresponding to a recess provided on the outer periphery of the plate stacked body. In this case, the decrease in size and weight of the plate stacked body is realized.
According to a seventh aspect of the present disclosure, the indoor heat exchanger of any one of the first to sixth aspects may be arranged such that the first heat transfer pipe is connected to a functional component via the first refrigerant passage. In this case, an actually-existing structure can be used for a connection part between the functional component and the heat transfer pipe.
According to an eighth aspect of the present disclosure, the indoor heat exchanger of the seventh aspect may be arranged such that the functional component is an expansion valve.
According to a ninth aspect of the present disclosure, the indoor heat exchanger of any one of the first to eighth aspects may be arranged such that the heat exchanging portion includes a first heat exchanging portion and a second heat exchanging portion, the first heat exchanging portion includes the first heat transfer pipe, and the second heat exchanging portion includes the second heat transfer pipe. For example, when the first heat transfer pipe included in the first heat exchanging portion and the first heat transfer pipe included in the second heat exchanging portion are connected via the plate stacked body, a bypass is necessary for the second refrigerant passage of the plate stacked body, with the result that a complex structure may be provided. The aspect of the present disclosure suppresses this problem.
According to a tenth aspect of the present disclosure, the indoor heat exchanger of any one of the first to ninth aspects may further include a connector connecting the plate stacked body to at least one of the third heat transfer pipe and the fourth heat transfer pipe in the stacked direction and may be arranged such that the length of the connector in the stacked direction is longer than the length of the refrigerant pipe in the stacked direction. Because the second refrigerant passage of the plate stacked body is formed of through holes and grooves of the plates, a corner portion tends to be formed so that a significant pressure loss may occur at the corner portion. In order to suppress the increase of the pressure loss, the heat transfer pipes are preferably connected to the first refrigerant passage of the refrigerant pipe in which the corner portion is unlikely to be formed. In this aspect of the present disclosure, because the length of the connector is longer than that of the refrigerant pipe, the refrigerant pipe can be provided between the heat transfer pipes and the plate stacked body. With this arrangement, any part of the plate stacked body does not overlap the refrigerant pipe and does not need to be cut out. Therefore, a structure in which the heat transfer pipes are connected to the first refrigerant passage of the refrigerant pipe is easily adopted.
Accordingly, the increase of the pressure loss is suppressed by adopting the structure in which the heat transfer pipes are connected to the first refrigerant passage of the refrigerant pipe.
According to an eleventh aspect of the present disclosure, the indoor heat exchanger of any one of the first to tenth aspects may be arranged such that the plates include: a first plate; and a second plate stacked at a position which is far from the heat transfer pipes in the stacked direction as compared to the first plate, and the second refrigerant passage includes: a first passage formed in the first plate; and a second passage which is formed both in the first plate and the second plate and which intersects with the first passage viewed in the stacked direction. In this case, a bypass is not provided on a flat surface of each of the plates, and the first passage intersects with the second passage so that the increase in size of the plate stacked body is suppressed in a surface direction along the flat surface of each of the plates.
According to a twelfth aspect of the present disclosure, an air conditioner comprises the indoor heat exchanger of any one of the first to eleventh aspects.

[Brief Description of Drawings]

FIG. 1 is a front view of an air conditioner of First Embodiment of the present disclosure, from which an exterior panel is detached.
FIG. 2 is a right side view of an indoor heat exchanger included in the air conditioner shown in FIG. 1 .
FIG. 3 is a perspective view of a plate stacked body shown in FIG. 1.
FIG. 4 is a plan view of the leftmost one of five plates forming the plate stacked body shown in FIG. 3 .
FIG. 5 is a plan view of the second leftmost one of the five plates forming the plate stacked body shown in FIG. 3 .
FIG. 6 is a plan view of the third leftmost one of the five plates forming the plate stacked body shown in FIG. 3 .
FIG. 7 is a plan view of the fourth leftmost one of the five plates forming the plate stacked body shown in FIG. 3 .
FIG. 8 is a plan view of the rightmost one of the five plates forming the plate stacked body shown in FIG. 3 .
FIG. 9 is a cross section of the plate stacked body, taken along a line IX-IX shown in FIG. 5.
FIG. 10 shows a plate stacked body, each connector, and a U-bend pipe of an indoor heat exchanger of Second Embodiment of the present disclosure.

[Preferred Embodiment of Invention]

The following will describe the overall structure of an air conditioner 1 of First Embodiment of the present disclosure, with reference to FIG. 1. In the following description, the directions such as "up/upward", "down/downward", "right/rightward", "left/leftward", "front/forward", and "rear/rearward" will be used on the premise that the air conditioner 1 is oriented as shown in FIG. 1.
The air conditioner 1 includes an indoor heat exchanger 10, a fan and a filter (not illustrated), a frame 1f, and an exterior panel (not illustrated).
The frame 1f forms a bottom portion and rear portion of the air conditioner 1. The frame 1f is long in one direction, and is attached to a wall surface of a room via an attaching plate (not illustrated) so that this one direction extends along the left-right direction in FIG. 1. The fan, the exterior panel, and the indoor heat exchanger 10 are attached to the frame 1f. The filter is attached to the exterior panel.
The indoor heat exchanger 10 is long in one direction (the left-right direction of FIG. 1) in the same manner as the frame 1f.
The following will detail the structure of the indoor heat exchanger 10 with reference to FIG. 1 to FIG. 9.
As shown in FIG. 1, the indoor heat exchanger 10 includes a heat exchanging portion 10u, a plate stacked body 30, U-bend pipes 22, and communication pipes 23. A part of one of the U-bend pipes 22 overlaps the plate stacked body 30 in a side view, and FIG. 1 illustrates this part by dotted lines.
The heat exchanging portion 10u includes fins 11, heat transfer pipes 12, and a pipe plate 14.
The fins 11 are thin plate-shaped, and provided so that each plate surface extends along the up-down direction and the front-rear direction. The fins 11 are aligned in the left-right direction at regular intervals.
The heat transfer pipes 12 extend in the left-right direction, and penetrate the fins 11.
For simplification, FIG. 1 illustrates only one or more of the heat transfer pipes 12 and partially illustrates only one or more of the fins 11.
A left end of each heat transfer pipe 12 is connected to that of another heat transfer pipe 12 via a U-shaped bent portion 21. A right end of each heat transfer pipe 12 is connected to that of another heat transfer pipe 12 via a U-bend pipe 22, a communication pipe 23, or the plate stacked body 30. The bent portions 21 are provided to the left of the fins 11. The U-bend pipes 22, the communication pipes 23, and the plate stacked body 30 are provided to the right of the fins 11.
The bent portions 21 are formed integrally with the heat transfer pipes 12 and, by bending a single pipe, (i) a pair of heat transfer pipes 12 and (ii) a bent portion 21 are formed as each U-shaped pipe. Meanwhile, each U-bend pipe 22 and each communication pipe 23 are welded to open ends of a U-shaped pipe (right ends of heat transfer pipes 12) bent as described above.
The U-bend pipe 22 and the communication pipe 23 are each equivalent to a "refrigerant pipe" of the present disclosure. The plate stacked body 30 includes five plates 31 to 35 (see FIG. 3) stacked in the left-right direction (stacked direction) . Each U-bend pipe 22, each communication pipe 23, and the plate stacked body 30 are provided with refrigerant passages. A refrigerant passage 22m formed in the U-bend pipe 22 and a refrigerant passage 23m (see FIG. 2) formed in the communication pipe 23 are each equivalent to a "first refrigerant passage" of the present disclosure. A refrigerant passage 30m (see FIG. 4 to FIG. 9) formed in the plate stacked body 30 is equivalent to a "second refrigerant passage" of the present disclosure.
A refrigerant ("first refrigerant" of the present disclosure) flowing in the refrigerant passages 22m and 23m is a liquid-phase refrigerant or a gas-phase refrigerant. A refrigerant ("second refrigerant" of the present disclosure) flowing in the refrigerant passage 30m is a gas-liquid two phase refrigerant. The temperature of the liquid-phase refrigerant is lower than that of the gas-liquid two phase refrigerant, and the temperature of the gas-phase refrigerant is higher than that of the gas-liquid two phase refrigerant. The following differences are larger than predetermined value, respectively: a difference between the temperature ("first temperature" of the present disclosure) of the liquid-phase refrigerant and the temperature ("second temperature" of the present disclosure) of the gas-liquid two phase refrigerant; and a difference between the temperature ("first temperature" of the present disclosure) of the gas-phase refrigerant and the temperature ("second temperature" of the present disclosure) of the gas-liquid two phase refrigerant.
As shown in FIG. 1, a diverter 18, an expansion valve 19, etc. are provided in the vicinity of the U-bend portions 22, the communication pipes 23, and the plate stacked body 30.
The pipe plate 14 is arranged so that a plate surface of the pipe plate 14 extends along the up-down direction and the front-rear direction, and provided to the right of the fins 11. The heat transfer pipes 12 penetrate the pipe plate 14. There is hardly a gap between the pipe plate 14 and each heat transfer pipe 12, and the pipe plate 14 supports the fins 11 and the heat transfer pipes 12. The U-bend pipes 22, the communication pipes 23, and the plate stacked body 30 are provided to the right of the pipe plate 14, i.e., to be opposite to the fins 11 over the pipe plate 14.
Although not illustrated, another pipe plate is provided to the left of the fins 11.
The heat transfer pipes 12 slightly protrude rightward as compared to a right side surface of the pipe plate 14. That is, end faces 12x of the heat transfer pipes 12 are positioned slightly to the right of the right side surface of the pipe plate 14.
As shown in FIG. 2, the pipe plate 14 includes a first pipe plate 141, a second pipe plate 142, a third pipe plate 143, and a fourth pipe plate 144. The indoor heat exchanger 10 is a bent-type apparatus in which the first to fourth pipe plates 141 to 144 are arranged so that each of the plates 141 to 144 forms an angle with an adjacent plate. The heat transfer pipes 12 penetrate each of the first to fourth pipe plates 141 to 144. In each U-shaped pipe (formed of (i) a pair of heat transfer pipes 12 and (ii) a bent portion 21 which are formed of a single bent pipe), the pair of heat transfer pipes 12 do not penetrate different two of the first to fourth plates 141 to 144.
The heat exchanging portion 10u is formed of a rear heat exchanging portion 10u1 including the first pipe plate 141 and a front heat exchanging portion 10u2 including the second to fourth pipe plates 142 to 144. The rear heat exchanging portion 10u1 is equivalent to a "first heat exchanging portion" of the present disclosure, and the front heat exchanging portion 10u2 is equivalent to a "second heat exchanging portion" of the present disclosure.
Among the heat transfer pipes 12 included in the rear heat exchanging portion 10u1, two adjacent heat transfer pipes 121a and 122a are connected to each other via a refrigerant passage 22m of a U-bend pipe 22. These two heat transfer pipes 121a and 122a form different U-shaped pipes (each of which is formed of (i) a pair of heat transfer pipes 12 and (ii) a bent portion 21 which are formed of a single bent pipe). The heat transfer pipe 121a is equivalent to a "first heat transfer pipe" of the present disclosure, and a heat transfer pipe 122a is equivalent to the "second heat transfer pipe" of the present disclosure. In this regard, when two heat transfer pipes 12 are "adjacent to each other", there is not another heat transfer pipe 12 between these two heat transfer pipes 12.
One (heat transfer pipe 121b) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122b) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. One (heat transfer pipe 121c) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122c) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. One (heat transfer pipe 121d) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122d) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. One (heat transfer pipe 121e) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122e) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. Each of the heat transfer pipes 121b, 121c, 121d, and 121e is equivalent to a "first heat transfer pipe" of the present disclosure, and each of the heat transfer pipes 122b, 122c, 122d, and 122e is equivalent to a "second heat transfer pipe" of the present disclosure.
The heat transfer pipe 121c is also connected to the expansion valve 19. The expansion valve 19 is equivalent to a "functional component" of the present disclosure, and attached to the communication pipe 23 connecting the heat transfer pipes 121c and 122c.
Except six heat transfer pipes 121a, 122a, 121b, 121c, 121d, and 121e connected to U-bend pipes 22 or communication pipes 23, the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 are connected to the plate stacked body 30 on the right side of the fins 11 in the left-right direction.
The plate stacked body 30 shown in FIG. 3 is attached to the rear heat exchanging portion 10u1. Another plate stacked body attached to the front heat exchanging portion 10u2 is structured in the same manner as the plate stacked body 30, and thus not illustrated and explained.
Among the heat transfer pipes 12 included in the rear heat exchanging portion 10u1, the plate stacked body 30 is attached via connectors 40 to heat transfer pipes 12 which are not connected to U-bend pipes 22 or communication pipes 23. The connectors 40 are cylindrical in shape, and refrigerant passages are provided inside the connectors 40. Each connector 40 extends in the left-right direction, and connects one of the above-described heat transfer pipes 12 to the plate stacked body 30 in the left-right direction. A left end of each connector 40 is connected to the end face 12x of one of the above-described heat transfer pipes 12, and a right end of each connector 40 is connected to a left side surface of the plate 31 of the plate stacked body 30.
Recesses 30x and 30y are provided on a part (rear part) of the outer periphery of the plate stacked body 30. The recesses 30x and 30y penetrate the plate stacked body 30 in the left-right direction. The recesses 30x and 30y are portions where the plates 31 to 35 are notched, i.e., cutouts on the plates 31 to 35. The U-bend pipes 22 are provided at positions corresponding to the recess 30y (see FIG. 4 to FIG. 8).
In the present embodiment, the length of the connectors 40 in the left-right direction is shorter than that of the U-bend pipes 22 in the left-right direction. A first distance D1 from the end face 12x of each heat transfer pipe 12 to a surface of the plate stacked body 30 in the left-right direction (stacked direction) is shorter (see FIG. 1) than a second distance D2 from the end face 12x of each heat transfer pipe 12 to a part of each U-bend pipe 22 in the left-right direction (stacked direction). In this regard, this surface of the plate stacked body 30 (a left side surface of the plate 31) is a surface closest to the end face 12x of each heat transfer pipe 12, and this part (top part) of each U-bend pipe 22 is a part furthest from the end face 12x of each heat transfer pipe 12. Therefore, as shown in FIG. 1, each U-bend pipe 22 overlaps the plate stacked body 30 viewed in the front-rear direction.
The following will detail the refrigerant passage 30m formed in the plate stacked body 30, with reference to FIG. 4 to FIG. 9.
The refrigerant passage 30m is formed of through holes formed on the plates 31 to 35 forming the plate stacked body 30.
As shown in FIG. 4, the plate 31 is provided with round holes (including round holes 313a and 314a described later). Into each of these round holes, a right end of a connector 40 (see FIG. 3) is inserted.
As shown in FIG. 5, the plate 32 is provided with round holes (including round holes 323x, 324x, and 323a described later) and slots (including slots 321y, 322y, 323y, and 324a described later). Each of these round holes and slots is communicated with one or two of the round holes formed on the plate 31.
As shown in FIG. 6, the plate 33 is provided with round holes (including a round hole 334a described later). Each of these round holes is communicated with one round hole or slot formed on the plate 32.
As shown in FIG. 7, the plate 34 is provided with slots (including slots 342x and 343a described later). Each of these slots is communicated with two of the round holes formed on the plate 33.
As shown in FIG. 8, the plate 35 is provided with a single round hole 35x. The round hole 35x is communicated with one of the slots formed on the plate 34.
The through holes (round holes or slots) formed on the plates 31 to 35 are communicated with each other so that the refrigerant passage 30m is formed.
Two heat transfer pipes 123a and 124a (two of the heat transfer pipes 12 included in the rear heat exchanging unit 10u1) shown in FIG. 2 are connected to each other via the refrigerant passage 30m formed of: the round holes 313a and 314a formed on the plate 31; the round hole 323a and the slot 324a formed on the plate 32; the round holes 333a and 334a formed on the plate 33; and the slot 343a formed on the plate 34. The heat transfer pipe 123a is equivalent to a "third heat transfer pipe" of the present disclosure, and the heat transfer pipe 124a is equivalent to a "fourth heat transfer pipe" of the present disclosure. These two heat transfer pipes 123a and 124a form different U-shaped pipes (each of which is formed of (i) a pair of heat transfer pipes 12 and (ii) a bent portion 21 which are formed of a single bent pipe).
As shown in FIG. 9, the slot 342x (see FIG. 7) formed on the plate 34 is formed across the four slots 321y, 322y, 323y, and 324a (see FIG. 5) formed on the plate 32. Each of the slots 321y, 322y, 323y, and 324a forms a first passage 30m1 of the refrigerant passage 30. The round holes 323x and 324x on the plate 32, the round holes on the plates 31 and 33, and the slot 342x on the plate 34 form a second passage 30m2 of the refrigerant passage 30m. One end of the slot 342x is connected to the round hole 323x, and the other end of the slot 342x is connected to the round hole 324x. Each first passage 30m1 intersects with the second passage 30m2 when viewed in the left-right direction (stacked direction; see FIG. 5).
The plate 32 is equivalent to a "first plate" of the present disclosure. The plate 34 is stacked at a position which is far from the heat transfer pipes 12 in the left-right direction (stacked direction) as compared to the plate 32. The plate 34 is equivalent to a "second plate" of the present disclosure.
As described above, in the present embodiment, not all heat transfer pipes 12 are connected via the refrigerant passage 30m of the plate stacked body 30. On the right side of the fins 11 in the left-right direction, some heat transfer pipes 12 (the heat transfer pipes 121a and 122a, the heat transfer pipes 121b and 122b, the heat transfer pipes 121c and 122c, the heat transfer pipes 121d and 122d, and the heat transfer pipes 121e and 122e) are connected via the refrigerant passages 22m of the U-bend pipes 22 or the refrigerant passages 23m of the communication pipes 23 (see FIG. 2), and the remaining heat transfer pipes 12 are connected via the refrigerant passage 30m of the plate stacked body 30 (see FIG. 3 to FIG. 8). This suppresses the increase in size of the plate stacked body 30.
The two adjacent heat transfer pipes 121a and 122a are connected to each other via a refrigerant passage 22m of a U-bend pipe 22 (see FIG. 4 and FIG. 8). This provides a simple structure. Furthermore, with the above-described arrangement, when a part of the plate stacked body 30 overlaps the U-bend pipes 22 and needs to be cut out because of the length of the U-bend pipes 22, etc., the area of a cutout part (the recess 30y) is made small and the influence on the refrigerant passage 30m formed on the plate stacked body 30 is suppressed.
A difference between the temperature of the refrigerant (first refrigerant) flowing in the refrigerant passages 22m of the U-bend pipes 22 and the temperature of the refrigerant (second refrigerant) flowing in the refrigerant passage 30m of the plate stacked body 30 is larger than the predetermined value. If the first refrigerant and the second refrigerant flow in the refrigerant passage 30m of the plate stacked body 30 while a temperature difference between the first refrigerant and the second refrigerant is larger than the predetermined value, heat exchange between the first refrigerant and the second refrigerant may occur in the plate stacked body 30 so that a significant heat loss occurs. In the present embodiment, the first refrigerant flows in the refrigerant passages 22m of the U-bend pipes 22, and the second refrigerant flows in the refrigerant passage 30m of the plate stacked body 30. With this arrangement, the heat exchange between the first refrigerant and the second refrigerant does not occur in the plate stacked body 30, and the significant heat loss does not occur.
The above-described first refrigerant is a liquid-phase refrigerant or a gas-phase refrigerant, and the above-described second refrigerant is a gas-liquid two phase refrigerant. The temperature of the liquid-phase refrigerant is lower than that of the gas-liquid two phase refrigerant, and the temperature of the gas-phase refrigerant is higher than that of the gas-liquid two phase refrigerant. In the present embodiment, a structure in which the heat exchange between the first refrigerant and the second refrigerant does not occur in the plate stacked body 30 is effectively realized.
A first distance D1 from the end face 12x of each heat transfer pipe 12 to a surface of the plate stacked body 30 in the left-right direction (stacked direction) is shorter (see FIG. 1) than a second distance D2 from the end face 12x of each heat transfer pipe 12 to a part of each U-bend pipe 22 in the left-right direction (stacked direction). In this regard, this surface of the plate stacked body 30 (a left side surface of the plate 31) is a surface closest to the end face 12x of each heat transfer pipe 12, and this part (top part) of each U-bend pipe 22 is a part furthest from the end face 12x of each heat transfer pipe 12. In this case, space is utilized by arranging the plate stacked body 30 so as to overlap the U-bend pipes 22 in side view.
The U-bend pipes 22 are provided at positions corresponding to the recess 30y provided on the outer periphery of the plate stacked body 30 (see FIG. 4 to FIG. 8). In this case, the decrease in size and weight of the plate stacked body 30 is realized.
The heat transfer pipe 121c (heat transfer pipe connected to a communication pipe 23) is connected to the expansion valve 19 (see FIG. 2) via a refrigerant passage 23m of the communication pipe 23. In this case, an actually-existing structure can be used for a connection part between the expansion valve 19 and a heat transfer pipe 12.
One (heat transfer pipe 121b) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122b) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. One (heat transfer pipe 121c) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122c) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. One (heat transfer pipe 121d) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122d) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. One (heat transfer pipe 121e) of the heat transfer pipes 12 included in the rear heat exchanging portion 10u1 is connected to one (heat transfer pipe 122e) of the heat transfer pipes 12 included in the front heat exchanging portion 10u2 via a refrigerant passage 23m of a communication pipe 23. For example, if the heat transfer pipes 121b and 122b are connected via the refrigerant passage 30m of the plate stacked body 30, a bypass is necessary for the refrigerant passage 30m of the plate stacked body 30, with the result that a complex structure may be provided. The present embodiment suppresses this problem.
The refrigerant passage 30m of the plate stacked body 30 includes: the first refrigerant passage 30m1 (see FIG. 5) formed of each of the slots 321y, 322y, 323y, and 324a formed on the plate 32; and the second refrigerant passage 30m2 (see FIG. 5 to FIG. 7) formed of the round holes 323x and 324x formed on the plate 32, the round holes formed on the plates 31 and 33, and the slot 342x formed on the plate 34. Each first passage 30m1 intersects with the second passage 30m2 when viewed in the left-right direction (stacked direction). In this case, a bypass is not provided on a flat surface of each of the plates 31 to 35, and the first passage 30m1 intersects with the second passage 30m2 so that the increase in size of the plate stacked body 30 is suppressed in a surface direction along the flat surface of each of the plates 31 to 35.

The following will describe an indoor heat exchanger of Second Embodiment of the present disclosure with reference to FIG. 10.
The indoor heat exchanger of Second Embodiment is structured in the same manner as the indoor heat exchanger 10 of First Embodiment, except in that the length of connectors 240 in the left-right direction (stacked direction) is longer than that of the connectors 40 of First Embodiment in the left-right direction (stacked direction).
In the present embodiment, the length of the connectors 240 in the left-right direction is longer than that of the U-bend pipes 22 in the left-right direction. Therefore, each U-bend pipe 22 does not overlap a plate stacked body 30 viewed in the front-rear direction.
Because the refrigerant passage 30m of the plate stacked body 30 is formed of the through holes and grooves of the plates 31 to 35, corner portions tend to be formed so that a significant pressure loss may occur at the corner portions. In order to suppress the increase of the pressure loss, the heat transfer pipes 12 are preferably connected to the refrigerant passages 22m of the U-bend pipes 22 in which the corner portions are unlikely to be formed. In the present embodiment, because the length of the connectors 240 in the left-right direction is longer than that of the U-bend pipes 22 in the left-right direction, the U-bend pipes 22 can be provided between the heat transfer pipes 12 and the plate stacked body 30. With this arrangement, any part of the plate stacked body 30 does not overlap the U-bend pipes 22 and does not need to be cut out for the U-bend pipes 22. Therefore, a structure in which the heat transfer pipes 12 are connected to the refrigerant passages of the U-bend pipes 22 is easily adopted. Accordingly, the increase of the pressure loss is suppressed by adopting this structure.

In the embodiments above, the refrigerant passage 30m of the plate stacked body 30 is formed of the through holes formed on the plates 31 to 35. However, the disclosure is not limited to this. For example, a part of or all of the refrigerant passage 30m may be formed of bottomed grooves which are half-etched, etc. and formed on the plates 31 to 35.
In the embodiments above, the U-bend pipes 22 (refrigerant pipes) are provided at positions corresponding to the recess 30y formed on the outer periphery of the plate stacked body 30. However, the disclosure is not limited to this. For example, the refrigerant pipes may be provided at positions corresponding to through holes or a recess which are/is formed on the center of the plate stacked body.
In the embodiments above, the refrigerant passage 30m (second refrigerant passage) of the plate stacked body 30 includes the passages 30m1 and 30m2 (the first passage and the second passage) intersecting with each other when viewed in the left-right direction (stacked direction). However, the second refrigerant passage may not include passages intersecting with each other when viewed in the stacked direction.
In the embodiments above, one heat transfer pipe (e.g., the heat transfer pipe 121b) included in the rear heat exchanging portion 10u1 (first heat exchanging portion) is connected to one heat transfer pipe (e.g., the heat transfer pipe 122b) included in the front heat exchanging portion 10u2 (second heat exchanging portion) via a refrigerant passage 23m (first refrigerant passage) of a communication pipe 23. However, the disclosure is not limited to this. For example, the above-described two heat transfer pipes 121b and 122b may be connected via a refrigerant passage 22m of a U-bend pipe 22 or may be connected via the refrigerant passage 30m (second refrigerant passage) of the plate stacked body 30.
In the embodiments above, examples of the first heat exchanging portion and the second heat exchanging portion are the rear heat exchanging portion 10u1 and the front heat exchanging portion 10u2 between which a bent part of the bent-type indoor heat exchanger 10 is provided. However, the disclosure is not limited to this. For example, the first heat exchanging portion and the second heat exchanging portion may be two heat exchanging portions which are aligned to be linear and between which the bent part of the indoor heat exchanger is not provided.
The functional component is not limited to the expansion valve, and may be a diverter, etc.
Although Embodiments have been described above, it will be understood that various changes in form and details are possible as long as the changes do not depart from the spirit and scope of the claims.

[Reference Signs List]

1 air conditioner
10 indoor heat exchanger
10u heat exchanging portion
10u1 rear heat exchanging portion (first heat exchanging portion)
10u2 front heat exchanging portion (second heat exchanging portion)
11 fin
12 heat transfer pipe
121a,121b,121c,121d,121e heat transfer pipe (first heat transfer pipe)
122a,122b,122c,122d,122e heat transfer pipe (second heat transfer pipe)
123a transfer pipe (third heat transfer pipe)
124a heat transfer pipe (fourth heat transfer pipe)
19 expansion valve (functional component)
22 U-bend pipe (refrigerant pipe)
22m refrigerant passage (first refrigerant passage)
23 communication pipe (refrigerant pipe)
23m refrigerant passage (first refrigerant passage)
30 plate stacked body
30m refrigerant passage (second refrigerant passage)
30m1 first passage
30m2 second passage
30x recess
32 plate (first plate)
34 plate (second plate)
40, 240 connector
D1 first distance
D2 second distance

Claims

An indoor heat exchanger comprising: a heat exchanging portion including a fin and heat transfer pipes penetrating the fin;
a refrigerant pipe in which a first refrigerant passage is formed; and

a plate stacked body which includes plates stacked in a stacked direction and in which a second refrigerant passage is formed,

the heat transfer pipes including a first heat transfer pipe, a second heat transfer pipe, a third heat transfer pipe, and a fourth heat transfer pipe,

the first heat transfer pipe being connected to the second heat transfer pipe via the first refrigerant passage, and

the third heat transfer pipe being connected to the fourth heat transfer pipe via the second refrigerant passage.
The indoor heat exchanger according to claim 1, wherein, the refrigerant pipe is a U-bend pipe, and
the first heat transfer pipe and the second heat transfer pipe are adjacent to each other.
The indoor heat exchanger according to claim 1, wherein, the refrigerant pipe is a U-bend pipe,
the temperature of a first refrigerant flowing in the first refrigerant passage is a first temperature, and

the temperature of a second refrigerant flowing in the second refrigerant passage is a second temperature, and a difference between the first temperature and the second temperature is larger than a predetermined value.
The indoor heat exchanger according to claim 3, wherein, the first refrigerant is a liquid-phase refrigerant or a gas-phase refrigerant, and
the second refrigerant is a gas-liquid two phase refrigerant.
The indoor heat exchanger according to claim 1, wherein, a first distance from end faces of the heat transfer pipes to a surface of the plate stacked body in the stacked direction is shorter than a second distance from the end faces of the heat transfer pipes to a part of the refrigerant pipe in the stacked direction, the surface of the plate stacked body being a surface closest to the end faces of the heat transfer pipes, and the part of the refrigerant pipe being a part furthest from the end faces of the heat transfer pipes.
The indoor heat exchanger according to claim 5, wherein, the refrigerant pipe is provided at a position corresponding to a recess provided on the outer periphery of the plate stacked body.
The indoor heat exchanger according to claim 1, wherein, the first heat transfer pipe is connected to a functional component via the first refrigerant passage.
The indoor heat exchanger according to claim 7, wherein, the functional component is an expansion valve.
The indoor heat exchanger according to claim 1, wherein, the heat exchanging portion includes a first heat exchanging portion and a second heat exchanging portion,
the first heat exchanging portion includes the first heat transfer pipe, and

the second heat exchanging portion includes the second heat transfer pipe.
The indoor heat exchanger according to claim 1, further comprising a connector connecting the plate stacked body to at least one of the third heat transfer pipe and the fourth heat transfer pipe in the stacked direction, wherein,
the length of the connector in the stacked direction is longer than the length of the refrigerant pipe in the stacked direction.
The indoor heat exchanger according to any one of claims 1 to 10, wherein, the plates include: a first plate; and a second plate stacked at a position which is far from the heat transfer pipes in the stacked direction as compared to the first plate, and
the second refrigerant passage includes:
a first passage formed in the first plate; and

a second passage which is formed both in the first plate and the second plate and which intersects with the first passage viewed in the stacked direction.
An air conditioner comprising the indoor heat exchanger according to claim 1.