CN110462296B

CN110462296B - Indoor unit of air conditioner

Info

Publication number: CN110462296B
Application number: CN201880021529.8A
Authority: CN
Inventors: 吉冈俊; 松本祥志; 吾郷祥太
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2017-03-27
Filing date: 2018-03-06
Publication date: 2021-05-28
Anticipated expiration: 2038-03-06
Also published as: WO2018180279A1; EP3604969A4; EP3604969A1; US20200232656A1; CN110462296A; JPWO2018180279A1

Abstract

Provided is an air conditioning indoor unit having high heat exchange performance. In an air-conditioning indoor unit (4), when the heat exchanger unit (42) is used as a condenser, at least a part of supercooled regions (Sc1, Sc2) of the heat exchanger unit (42) are disposed at a position lower than an upper end (40u) of a wall portion (40w) of a drain pan (40).

Description

Indoor unit of air conditioner

Technical Field

The present invention relates to an indoor unit of an air conditioner.

Background

Currently, air-conditioning indoor units that blow out conditioned air are being utilized. For example, patent document 1 (japanese patent application laid-open publication No. 2011-099609) discloses an air-conditioning indoor unit equipped with a fin-and-tube heat exchanger.

Disclosure of Invention

Technical problem to be solved by the invention

In recent years, it has been studied to install a microchannel heat exchanger using a flat multi-hole tube in an air-conditioning indoor unit. In a heat exchanger using flat multi-hole tubes, heat exchange regions having different numbers of divisions of refrigerant flow paths are formed. In addition, in the air-conditioning indoor unit, the wind speed distribution of the air flow generated by the centrifugal fan greatly varies depending on the position due to the influence of the internal structure and the like. Therefore, in an air-conditioning indoor unit to which a heat exchanger using a flat multi-hole tube is attached, the heat exchange performance may be greatly reduced depending on the internal wind velocity distribution and the position where the heat exchanger is disposed.

The technical problem of the invention is to provide an air-conditioning indoor unit with high heat exchange performance.

Technical scheme for solving technical problem

An air conditioning indoor unit according to a first aspect of the present invention includes: a housing disposed indoors; a fan disposed within the housing; a heat exchanger disposed in the housing and arranged vertically, the heat exchanger having a plurality of flat perforated tubes; and a drain pan disposed below the heat exchanger. Here, the heat exchanger is divided into an upper heat exchange region and a lower heat exchange region. In the case where the indoor heat exchanger is used as a condenser, a supercooling region formed of one or more flat perforated tubes for supercooling a refrigerant flowing inside is formed in the lower heat exchange region. The drain pan has a bottom portion provided below the heat exchanger, and a wall portion provided upright from the bottom portion and on a leeward side of the heat exchanger. Further, in this air-conditioning indoor unit, at least a part of the supercooling region is arranged at a position lower than the upper end of the wall portion of the drain pan.

In the air-conditioning indoor unit according to the first aspect, at least a part of the supercooling region of the heat exchanger is disposed at a position lower than the upper end of the wall portion of the drain pan, and therefore, the heat exchange efficiency can be improved.

In the present invention, the term "indoor" is used to distinguish from other rooms, and includes not only the meaning of an indoor space defined by wall surfaces but also the meaning of a space on the rear surface side of an indoor ceiling, for example.

In the present invention, the structure in which the plurality of flat perforated tubes are arranged "vertically" means any structure in which the positions of the centers of gravity of the flat perforated tubes are arranged vertically. Therefore, in this configuration, the upper surface and/or the lower surface of each flat perforated tube is not limited to be vertically aligned so as to be along the horizontal direction, and the upper surface and/or the lower surface of each flat perforated tube is vertically aligned so as to be along a direction inclined from the horizontal direction. In this configuration, the plurality of flat perforated tubes are not limited to being vertically arranged in the vertical direction, and may be vertically arranged in a direction inclined from the vertical direction.

In the air-conditioning indoor unit according to the second aspect of the present invention, the area of the upper heat exchange region is larger than the area of the lower heat exchange region.

In the air-conditioning indoor unit according to the second aspect, the area of the upper heat exchange region is larger than the area of the lower heat exchange region, and therefore the air-conditioning indoor unit having high heat exchange efficiency can be improved.

In the air-conditioning indoor unit according to the third aspect of the present invention, in addition to the air-conditioning indoor unit according to the first or second aspect, at least a part of the supercooling region is disposed in the vicinity of the upper end of the wall portion of the drain pan. With the above configuration, the heat exchanger having a large heat exchange area between the gas refrigerant and the air can be disposed above the drain pan.

In the air-conditioning indoor unit according to the fourth aspect of the present invention, in addition to the air-conditioning indoor unit according to any one of the first to third aspects, at least a part of the supercooling region is disposed at a position across an upper end of the wall portion of the drain pan. With the above configuration, the heat exchanger having a high heat exchange rate with the gas refrigerant can be disposed above the drain pan.

An air-conditioning indoor unit according to a fifth aspect of the present invention is the air-conditioning indoor unit according to any one of the first to fourth aspects, wherein the casing has a suction port at a lower portion, the fan is a centrifugal fan, and the heat exchanger is disposed in the casing so as to surround the centrifugal fan.

In the air-conditioning indoor unit described in the fifth aspect, for example, in the ceiling-embedded air-conditioning indoor unit, the heat exchange efficiency can be improved.

An air-conditioning indoor unit according to a sixth aspect of the present invention is the air-conditioning indoor unit according to any one of the first to fourth aspects, wherein the casing has a suction port on a side, and the partition plate is provided inside the casing. Here, the partition plate is a member for forming a heat exchanger chamber in which the heat exchanger is disposed in communication with the suction port, and an air blowing chamber in which the fan is disposed in communication with the heat exchanger chamber.

In the air-conditioning indoor unit described in the sixth aspect, for example, in the duct-type air-conditioning indoor unit, the heat exchange efficiency can be improved.

In the air-conditioning indoor unit according to the seventh aspect of the present invention, in addition to the air-conditioning indoor unit according to any one of the first to sixth aspects, a heat exchanger unit including a plurality of heat exchangers is used as the heat exchanger.

In the air-conditioning indoor unit according to the seventh aspect, the heat exchange efficiency can be improved in the air-conditioning indoor unit in which the heat exchanger unit including the plurality of heat exchangers is installed.

In the air-conditioning indoor unit according to the eighth aspect of the present invention, in addition to the air-conditioning indoor unit according to the seventh aspect, at least a part of the supercooling region of the heat exchanger disposed most downstream with respect to the fan in the heat exchanger unit is disposed at a position lower than the upper end of the wall portion of the drain pan.

In the air-conditioning indoor unit according to the eighth aspect, the heat exchange efficiency can be further improved in the air-conditioning indoor unit in which the heat exchanger unit including the plurality of heat exchangers is installed.

Effects of the invention

According to the air conditioning indoor unit described in the first aspect, the heat exchange efficiency can be improved.

According to the air-conditioning indoor unit described in the second aspect, an air-conditioning indoor unit having high heat exchange efficiency can be provided.

In the air-conditioning indoor unit according to the third aspect, the heat exchanger having a large heat exchange area between the gas refrigerant and the air can be disposed above the drain pan.

In the air conditioning indoor unit according to the fourth aspect, the heat exchanger having a high heat exchange rate with the gaseous refrigerant can be disposed above the drain pan.

The air-conditioning indoor unit according to the fifth aspect can improve heat exchange efficiency, for example, in a ceiling-embedded air-conditioning indoor unit.

The air-conditioning indoor unit according to the sixth aspect can improve the heat exchange efficiency, for example, in a duct-type air-conditioning indoor unit.

According to the air-conditioning indoor unit described in the seventh aspect, in the air-conditioning indoor unit in which the heat exchanger unit including the plurality of heat exchangers is installed, the heat exchange efficiency can be improved.

According to the air-conditioning indoor unit described in the eighth aspect, in the air-conditioning indoor unit in which the heat exchanger unit including the plurality of heat exchangers is installed, the heat exchange efficiency can be further improved.

Drawings

Fig. 1 is a schematic configuration diagram of an air conditioner 1 according to a first embodiment of the present invention.

Fig. 2 is an external perspective view of the indoor unit 4 of the ceiling-mounted air conditioner according to the same embodiment.

Fig. 3 is a schematic side sectional view of the indoor unit 4 of the ceiling-mounted air conditioner of the same embodiment.

Fig. 4 is a schematic plan view showing a state where the ceiling 33 is removed from the ceiling-embedded indoor unit 4 according to the same embodiment.

Fig. 5 is a partially enlarged view for explaining the structure of the drain water receiving groove 40i in the same embodiment.

Fig. 6 is a schematic perspective view of a heat exchanger 42a used in the heat exchanger unit 42 of the same embodiment.

Fig. 7 is a schematic longitudinal sectional view of a heat exchanger used in the heat exchanger unit 42 of the same embodiment.

Fig. 8 is a schematic perspective view showing another example of a heat exchanger 42a used in the heat exchanger unit 42 of the same embodiment.

Fig. 9 is a schematic diagram showing the structure of a heat exchanger unit 42 according to the same embodiment.

Fig. 10 is a schematic diagram showing the structure of a heat exchanger unit 42 according to the same embodiment.

Fig. 11 is a schematic diagram showing the structure of a first heat exchanger 52 according to the same embodiment.

Fig. 12 is a schematic diagram showing the structure of a second heat exchanger 62 according to the same embodiment.

Fig. 13 is a diagram for explaining an internal state when the heat exchanger unit 42 of the same embodiment is used as a condenser.

Fig. 14 is a diagram showing the wind speed distribution between the drain pan 40 and the inner wall of the housing 31 in the same embodiment.

Fig. 15 is a view showing the streamline distribution of the air flow between the drain pan 40 and the inner wall of the housing 31 of the same embodiment.

Fig. 16 is a schematic diagram showing a planar shape of the heat exchanger unit 42 of the same embodiment.

Fig. 17 is a schematic view showing the structure of the indoor heat exchanger according to modification 1A.

Fig. 18 is a schematic view showing the structure of the indoor heat exchanger according to modification 1A.

Fig. 19 is a schematic diagram showing an example of a heat exchanger unit according to modification 1B.

Fig. 20 is a schematic diagram showing an example of a heat exchanger unit of modification 1D.

Fig. 21 is a schematic sectional view of a ducted indoor unit 4S according to a second embodiment of the present invention.

Fig. 22 is a schematic view showing a modification of the indoor unit 4S of the same embodiment.

Detailed Description

Hereinafter, an embodiment of an air conditioner and a modification thereof according to the present invention will be described with reference to the drawings. The specific configuration of the air conditioner of the present invention is not limited to the following embodiments and modifications thereof, and can be modified within a range not departing from the gist of the invention.

< first embodiment >

(1) Overview of air conditioner

(1-1) basic Structure of air conditioner

The air conditioner 1 is a device capable of performing indoor cooling and heating of a building or the like by performing a vapor compression refrigeration cycle. The air conditioner 1 is mainly configured by connecting the outdoor unit 2 and the indoor unit 4. Here, the outdoor unit 2 and the indoor unit 4 are connected via the liquid refrigerant communication tube 5 and the gas refrigerant communication tube 6. The air conditioner 1 also controls various operations by the control unit 8 including the indoor control unit 8a and the outdoor control unit 8. The control unit 8 controls various devices, valves, and the like based on detection signals from various sensors.

Here, although the paired air conditioner 1 in which one outdoor unit 2 is connected to one indoor unit 4 is illustrated, the air conditioner 1 of the present embodiment may be a multi-type air conditioner in which a plurality of indoor units are connected to one outdoor unit.

(1-2) basic operation of air conditioner

Next, a basic operation of the air conditioner 1 will be described. As basic operations, the air conditioner 1 can perform a cooling operation and a heating operation. The air conditioner 1 can also perform a defrosting operation, an oil return operation, and the like. These operations are controlled by the control unit 8.

(1-2-1) Cooling operation

In the cooling operation, the four-way selector valve 22 constitutes the refrigerant circuit 10 as indicated by the solid line in fig. 1. In the refrigerant circuit 10, a low-pressure gas refrigerant is compressed by the compressor 21 to become a high-pressure gas refrigerant. The high-pressure gaseous refrigerant is sent to the outdoor heat exchanger 23 through the four-way selector valve 22. The high-pressure gas refrigerant sent to the outdoor heat exchanger is condensed by heat exchange with outdoor air in the outdoor heat exchanger 23. Thereby, the high-pressure gas refrigerant becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is decompressed by the expansion valve 24 to become a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant is sent to the indoor heat exchanger 42 via the liquid refrigerant communication tube 5 and the liquid-side connection tube 5 a. Next, the refrigerant exchanges heat with air blown out from the indoor fan 41 in the indoor heat exchanger 42 and evaporates. Thereby, the refrigerant sent to the indoor heat exchanger 42 becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant is sent again to the compressor 21 via the gas-side connection pipe 6a, the gas refrigerant communication pipe 6, and the four-way selector valve 22.

(1-2-2) heating operation

In the heating operation, the four-way selector valve 22 is configured as the refrigerant circuit 10 shown by the broken line in fig. 1. In the refrigerant circuit 10, a low-pressure gas refrigerant is compressed by the compressor 21 to become a high-pressure gas refrigerant. The high-pressure gas refrigerant is sent to the indoor heat exchanger 42 via the four-way selector valve 22, the gas refrigerant communication tube 6, and the gas-side connection tube 6 a. The high-pressure gas refrigerant sent to the indoor heat exchanger 42 exchanges heat with air blown out from the indoor fan 41 and condenses. Thereby, the high-pressure gas refrigerant becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is sent to the expansion valve 24 via the liquid-side connection tube 5a and the liquid refrigerant communication tube 5. The high-pressure liquid refrigerant is decompressed by the expansion valve 24 to become a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant is sent to the outdoor heat exchanger 23. Next, the refrigerant is heat-exchanged with outdoor air and evaporated in the outdoor heat exchanger 23. Thereby, the refrigerant sent to the outdoor heat exchanger 23 becomes a low-pressure gas refrigerant. The low-pressure gaseous refrigerant is sent again to the compressor 21 via the four-way selector valve 22.

(2) Structure of indoor unit

The air conditioner of the present embodiment includes the following configuration for the indoor unit in addition to the basic configuration described above.

In the present embodiment, the term "indoor" is used to distinguish from other rooms, and includes not only the meaning of an indoor space defined by wall surfaces but also the meaning of a space on the rear surface side of an indoor ceiling, for example.

(2-1) basic Structure of indoor Unit

The indoor unit 4 is installed indoors and constitutes a part of the refrigerant circuit 10. The indoor unit 4 mainly includes an indoor fan 41, an indoor heat exchanger 42, and an indoor control unit 8 a.

The indoor fan 41 draws indoor air into the indoor unit 4. This enables heat exchange between the indoor air and the refrigerant in the indoor heat exchanger 42. The indoor fan 41 supplies the indoor air heat-exchanged in the indoor heat exchanger 42 to the room as supply air. As the indoor fan 41, a centrifugal fan, a sirocco fan, or the like is used. The indoor fan 41 is driven by an indoor fan motor capable of controlling the number of rotations.

The indoor heat exchanger 42 functions as an "evaporator" of the refrigerant to cool the indoor air during the cooling operation, and functions as a "condenser" (radiator) of the refrigerant to heat the indoor air during the heating operation. The indoor heat exchanger 42 is connected to the liquid-refrigerant communication tube 5 and the gaseous-refrigerant communication tube 6. Further details regarding the indoor heat exchanger 42 will be described later.

The indoor control unit 8a controls the operation of each unit constituting the indoor unit 4. Specifically, the indoor control unit 8a includes a microcomputer, a memory, and the like, and controls the operation of the indoor unit 4 based on detection values of various sensors and the like provided in the indoor unit 4. The indoor control unit 8a communicates a control signal with a remote controller (not shown) for independently operating the indoor unit 4, and communicates a control signal with the outdoor control unit 8b via a transmission line.

In addition, various sensors are provided in the indoor unit 4. This detects the temperature of the refrigerant in the indoor heat exchanger 42, the temperature of the indoor air sucked into the indoor unit 4, and the like.

(2-2) ceiling-buried indoor Unit

The indoor unit 4 of the present embodiment can employ a type of structure called a ceiling-embedded type. Fig. 2 is an external perspective view of the ceiling-embedded indoor unit 4 of the present embodiment. Fig. 3 is a schematic cross-sectional view of the ceiling-embedded indoor unit 4 of the present embodiment. Here, fig. 3 shows A cross section A-O-A in fig. 4 described later. Fig. 4 is a schematic plan view showing a state in which the ceiling 33 of the ceiling-embedded indoor unit 4 of the present embodiment is removed.

The ceiling-embedded indoor unit accommodates an indoor fan 41 and an indoor heat exchanger 42 in the casing 31. Further, a drain pan 40 is mounted to a lower portion of the housing 31.

(2-2-1) outer case

The housing 31 accommodates various constituent devices therein. The casing 31 mainly includes a casing main body 31a and a decorative panel 32 disposed below the casing main body 31 a. As shown in fig. 3, the housing main body 31a is disposed on a ceiling U in a room to be supplied with conditioned air. An opening is formed in the ceiling U, and the housing body 31a is inserted into the opening of the ceiling U. Further, the decorative panel 32 is configured to be embedded in an opening of the ceiling U.

As shown in fig. 3 and 4, the housing main body 31a is a box-like body having an approximately octagonal shape with its long sides and short sides alternately formed and a bottom surface opened in a plan view. Specifically, the case main body 31a includes a top plate 33 and a side plate 34, the top plate 33 has a substantially octagonal shape in which long sides and short sides are alternately continuous, and the side plate 34 extends downward from a peripheral edge of the top plate 33. The side plates 34 are constituted by

side plates

34a, 34b, 34c, 34d corresponding to the long sides of the top plate 33 and

side plates

34e, 34f, 34g, 34h corresponding to the short sides of the top plate 33. The side plate 34h has a portion through which the liquid-side connection pipe 5a and the gas-side connection pipe 6a pass, and can connect the

refrigerant communication pipes

5 and 6 to the indoor heat exchanger 42.

As shown in fig. 2 to 4, the decorative panel 32 is a plate-like body having a substantially rectangular shape in plan view, and the decorative panel 32 is mainly constituted by a panel main body 32a fixed to the lower end portion of the casing main body 31 a. The panel main body 32a includes: a suction port 35 for sucking air in the air-conditioned room at substantially the center of the panel main body 32 a; and an air outlet 36 formed so as to surround the periphery of the air inlet 35 in a plan view and configured to blow air into the air-conditioned room. The suction port 35 is an approximately quadrangular opening. Suction port 35 is provided with a suction grill 37 and a filter 38, and this filter 38 removes dust from the air sucked through suction port 35. The outlet 36 is an opening of a substantially quadrilateral ring shape.

Horizontal fins

39a, 39b, 39c, and 39d are provided in the air outlet 36, and the

horizontal fins

39a, 39b, 39c, and 39d adjust the direction of the air blown into the air-conditioned room so as to correspond to the sides of the rectangle of the panel body 32 a.

(2-2-2) Drain tray

The drain pan 40 is a member for receiving drain water generated by condensation of moisture in the air in the indoor heat exchanger 42. The drain pan 40 is mounted to a lower portion of the housing main body 31 a. The drain pan 40 is formed with blow-out

holes

40a, 40b, 40c, 40d, 40e, 40f, and 40g, a suction hole 40h, and a drain water receiving groove 40 i. The outlet holes 40a to 40g are formed so as to communicate with the outlet port 36 of the decorative panel 32. The suction hole 40h is formed to communicate with the suction port 35 of the decorative panel 32. The drain water receiving groove 40i is formed below the indoor heat exchanger 42. In addition, a bell mouth 41c is disposed in the suction hole 40h of the drain pan 40, and the bell mouth 41c guides the air sucked from the suction port 35 toward the impeller 41b of the indoor fan.

As shown in fig. 5, the drain water receiving groove 40i includes a bottom portion 40t and a wall portion 40w, wherein the bottom portion 40t is provided below the indoor heat exchanger 42, and the wall portion 40w is provided on the leeward side of the indoor heat exchanger 42 and stands from the bottom portion 40 t. When the indoor heat exchanger 42 is used as a condenser, a supercooling region Sc formed of one or more flat multi-hole tubes for supercooling the refrigerant flowing inside is formed. The indoor unit 4 of the present embodiment is configured such that at least a part of the supercooled region Sc of the indoor heat exchanger 42 is disposed at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40. In addition, the above configuration may be: a structure in which the entire supercooling region Sc is disposed at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40; a structure in which a part of the supercooling region Sc is disposed in the vicinity of the upper end 40 u; and a structure in which a part of the supercooled region Sc is disposed at a position over the upper end 40 u.

(2-2-3) indoor Fan

The indoor fan 41 is constituted by a centrifugal blower. Here, the indoor fan 41 sucks indoor air into the casing main body 31a through the suction port 35 of the decorative panel 32, and blows out the air from the casing main body 31a through the blowing port 36 of the decorative panel 32. Specifically, the indoor fan 41 includes a fan motor 41a and an impeller 41b, the fan motor 41a is provided at the center of the top plate 33 of the casing main body 31a, and the impeller 41b is coupled to the fan motor 41a and is driven to rotate. The impeller 41b has turbine blades. The impeller 41b sucks air into the impeller 41b from below, and the sucked air is blown out toward the outer peripheral side of the impeller 41b in a plan view.

(2-2-4) indoor Heat exchanger

The indoor heat exchanger 42 is disposed inside the casing 31 in a bent manner so as to surround the periphery of the indoor fan 41 in a plan view. The liquid side of the indoor heat exchanger 42 is connected to the liquid refrigerant communication tube 5 via a liquid-side connection tube 5 a. Further, the gas side of the indoor heat exchanger 42 is connected to the gas refrigerant communication tube 6 via a gas-side connection tube 6 a. The indoor heat exchanger 42 functions as an evaporator of the refrigerant during the cooling operation and functions as a condenser of the refrigerant during the heating operation. Thus, the indoor heat exchanger 42 exchanges heat between the air blown out from the indoor fan 41 and the refrigerant, cools the air during the cooling operation, and heats the air during the heating operation.

(2-2-4-1) basic Structure of Heat exchanger

Fig. 6 is a schematic perspective view showing a basic structure of a heat exchanger 42a used in the indoor heat exchanger 42. In fig. 6, refrigerant pipes, communication pipes, and the like are not shown. Fig. 7 is a schematic longitudinal sectional view of a heat exchanger used in the heat exchanger 42 a.

The heat exchanger 42a is a fin-inserted laminated heat exchanger, and mainly includes a heat transfer tube 421 made of flat porous tubes, a plurality of fins 422, and two

headers

423 and 424.

The heat transfer pipe 421 is implemented by a flat perforated pipe. Here, both ends of the heat transfer pipe 421 are connected to the

headers

423 and 424, respectively. The heat transfer tubes 421 are arranged in a plurality of stages with a gap therebetween in a state where the flat surface portions are oriented in the vertical direction. Specifically, the heat transfer pipe 421 has upper and lower flat surface portions constituting a heat transfer surface, and a plurality of small refrigerant flow paths 421a through which the refrigerant flows. As the refrigerant flow path 421a, a flow path having a small flow path hole having a circular shape with an inner diameter of 1mm or less or a polygonal shape having the same cross-sectional area as the circular shape is used. In addition, the heat transfer pipe 421 is formed of aluminum or an aluminum alloy.

The fins 422 are inserted into the multilayer heat transfer pipe 421 arranged between the

headers

423, 424. Specifically, the fin 422 has a plurality of notches 422a formed therein, which extend in a horizontally elongated manner. The shape of the notch 422a substantially matches the outer shape of the cross section of the heat transfer pipe 421. Therefore, the notch 422a is engaged with the outer surface of the heat transfer pipe 421, and can be inserted so as to contact the heat transfer pipe 421. In addition, the fins 422 are formed of aluminum or an aluminum alloy. The fins 422 may have various shapes, and may have a wave shape as shown in fig. 8, for example.

The two

headers

423, 424 have the following functions, respectively: a function of supporting the heat transfer pipe 421; a function of guiding the refrigerant to the refrigerant flow path 421a of the heat transfer pipe 421; the function of collecting the refrigerant flowing out of the refrigerant flow path 421 a.

(2-2-4-2) Structure of Heat exchanger Unit

The indoor heat exchanger 42 of the present embodiment is constituted by a heat exchanger unit in which a plurality of the heat exchangers 42a described above are combined. In the following description, for convenience, the heat exchanger unit will be described with reference to "symbol 42" indicating an indoor heat exchanger. Further, the heat exchanger unit 42 includes at least a first heat exchanger 52 and a second heat exchanger 62. Here, the first heat exchanger 52 and the second heat exchanger 62 have the same configuration as the heat exchanger 42a described above, and the reference numerals are replaced for convenience. Specifically, in the following description, the first number of the reference numeral is set to "4" when the configuration of the entire heat exchanger unit is described, the first number of the reference numeral is replaced with "5" when the first heat exchanger 52 is described, and the first number of the reference numeral is replaced with "6" when the second heat exchanger 62 is described. For example, the heat transfer tubes of the first heat exchanger 52 or the second heat exchanger 62 have the same configuration as the heat transfer tubes 421 described above, and therefore, the description will be given by using the reference numerals 521 or 621, instead of the reference numerals 421.

Fig. 9 is a schematic diagram showing the structure of the heat exchanger unit 42 of the present embodiment. The heat exchanger unit 42 includes a first heat exchanger 52 disposed on the windward side of the air flow generated by the indoor fan (fan) 41, and a second heat exchanger 62 disposed in parallel with the first heat exchanger 52 on the leeward side of the air flow generated by the indoor fan 41. Here, the first direction D1 is opposite to the second direction D2, where the first direction D1 is a flow direction of the refrigerant flow from the first header 523 to the second header 524 of the first heat exchanger 52, and the second direction D2 is a flow direction of the refrigerant flow from the upper third header 523U to the upper fourth header 624U of the second heat exchanger 62. In fig. 9, the first heat exchanger 52 and the second heat exchanger 62 are shown separately for convenience of explanation, but the first heat exchanger 52 and the second heat exchanger 62 are disposed very close to each other to function as a single unit (see fig. 10).

The first heat exchanger 52 includes a first header 523 and a second header 524, and a first flat tube group 500, and the first flat tube group 500 is constituted by a plurality of flat multi-hole tubes (heat transfer tubes) connected to the first header 523 and the second header 523, respectively. A plurality of flat perforated tubes are arranged vertically in the first flat tube group 500. In the first flat tube group 500, as shown in fig. 11, one or more flat porous tubes on the upper side form an upper first heat exchange area 500U, and one or more flat porous tubes on the lower side form a lower first heat exchange area 500L.

As shown in fig. 11, the first header 523 includes an upper first header 523U and a lower first header 523L, wherein the upper first header 523U is connected to the upper first heat exchange area 500U, and the lower first header 523L is connected to the lower first heat exchange area 500L. A gas-side connection pipe 6a (gas refrigerant pipe) through which gas refrigerant flows is connected to the upper first header 523U. Further, the lower first header 523L is connected to the

connection pipes

525 and 526. Thereby, the upper second header 524U is coupled to the lower first header 523L. Further, the internal space of the first header 523 is partitioned vertically (here, into two parts) by a partition plate 523 a. This provides a structure in which the upper first header 523U and the lower first header 523L are not communicated with each other inside.

As shown in fig. 11, the second header 524 includes an upper second header 524U and a lower second header 524L, the upper second header 524U being connected to the upper first heat exchange area 500U, and the lower second header 524L being connected to the lower first heat exchange area 500L. The upper second header 524U is connected to connecting

pipes

525 and 526. Thereby, the upper second header 524U is coupled to the lower first header 523L. Further, a liquid-side connection pipe 5a through which a liquid refrigerant flows is connected to the lower second header 524L. In addition, the internal space of the second header 524 is divided up and down (here, into two sections) by a partition plate 524 a. This provides a structure in which the upper second headers 524U and the lower second headers 524L are not communicated with each other inside.

The

connection pipes

525 and 526 are pipes for connecting the upper second header 524U and the lower first header 523L. Further, temperature measuring instruments for measuring the temperature of the refrigerant are attached to the connecting

pipes

525 and 526.

The second heat exchanger 62 has a third header 623 and a fourth header 624, and a second flat tube group 600, wherein the second flat tube group 600 is formed of a plurality of flat perforated tubes connected to the third header 623 and the fourth header 624, respectively. A plurality of flat perforated tubes are arranged vertically in the second flat tube group 600. In the second flat tube group 600, as shown in fig. 12, one or more flat porous tubes on the upper side form an upper side second heat exchange region 600U, and one or more flat porous tubes on the lower side form a lower side second heat exchange region 600L.

As shown in fig. 12, the third header 623 includes an upper third header 623U and a lower third header 623L, wherein the upper third header 623U is connected to the upper second heat exchange area 600U, and the lower third header 623L is connected to the lower second heat exchange area 600L. In detail, the internal space of the third header 623 is divided up and down (here, into two parts) by a partition plate 623 a. The space 623g above the partition plate 623a is connected to the upper second heat exchange area 600U, and the space 623h below the partition plate is connected to the lower second heat exchange area 600L. Further, a gas-side connecting pipe 6a is connected to the upper third header 623U. Further, a liquid-side connecting pipe 5a is connected to the lower third header 623L.

As shown in fig. 12, the fourth header 624 has an upper fourth header 624U connected to the upper second heat exchange area 600U and a lower fourth header 624L connected to the lower second heat exchange area 600L. In detail, the inner space of the fourth header 624 is divided up and down (here, into two parts) by a partition plate 624 a. The upper space 624i of the partition plate 624a is connected to the upper second heat exchange area 600U, and the lower space 624j of the partition plate 624a is connected to the lower second heat exchange area 600L. The fourth header 624 has a "folded portion" that connects the upper fourth header 624U and the lower fourth header 624L and folds the refrigerant flowing from the third header 623 side back toward the third header 623 side. Specifically, the fourth header 624 has a connection pipe 625 that connects the upper fourth header 624U and the lower fourth header 624L as a turn-back portion. A temperature measuring instrument for measuring the temperature of the refrigerant is attached to the connecting pipe 625.

(3) Feature(s)

(3-1)

In the heat exchanger unit 42, the first heat exchanger 52 has an upper first heat exchange area 500U and a lower first heat exchange area 500L, a connection port connected to the gas-side connection pipe 6a is disposed in the upper first heat exchange area 500U, and a connection port connected to the liquid-side connection pipe 5a is disposed in the lower first heat exchange area 500L. The second heat exchanger 62 is formed with an upper second heat exchange area 600U and a lower second heat exchange area 600L, and a connection port connected to the gas-side connection pipe 6a is disposed in the upper second heat exchange area 600U and a connection port connected to the liquid-side connection pipe 5a is disposed in the lower second heat exchange area 600L.

Therefore, when the heat exchanger unit 42 is used as a condenser, the internal state of the heat exchange region is the state shown in fig. 13, and the supercooling regions Sc1, Sc2 composed of one or more flat multi-hole tubes are formed in the lower first heat exchange region 500L and the lower second heat exchange region 600L. In fig. 13, the hatching of the regions Sc1 and Sc2 indicates supercooled regions where the refrigerant is supercooled, and the hatching of the regions Sh1 and Sh2 indicates superheated regions where the refrigerant is superheated.

Here, in the indoor unit 4 (air-conditioning indoor unit) of the present embodiment, at least a part of the supercooled regions Sc1, Sc2 of the heat exchanger unit 42 is disposed at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40. Therefore, in the indoor unit 4 of the present embodiment, the heat exchange efficiency can be improved as compared with the configuration in which the entire supercooled region Sc is disposed at a position higher than the upper end 40u of the wall portion 40w of the drain pan 40.

As a supplement, according to the study of the inventors of the present invention, it is known that in the indoor unit 4, the flow velocity (wind speed) of the air flow becomes fast at the space above the drain pan 40. Specifically, the wind speed distribution between the drain pan 40 and the inner wall of the housing 31 is shown as a graph shown in fig. 14. In fig. 14, the vertical axis represents the position in the vertical direction inside the housing 31, and the horizontal axis represents the wind speed. As can be seen from fig. 14, in the indoor unit 4, the wind speed becomes faster in the space above the drain pan 40. In addition, the streamline distribution of the air flow between the drain pan 40 and the inner wall of the housing 31 is shown as shown in fig. 15.

In the configuration of the indoor unit 4 according to the present embodiment, the heat exchange regions (mainly, the lower

heat exchange regions

500L and 600L) that perform heat exchange between the liquid refrigerant and the air are disposed below the upper end 40U of the wall portion 40w of the drain pan 40, and the heat exchange regions (mainly, the upper

heat exchange regions

500U and 600U) that perform heat exchange between the gas refrigerant and the air are disposed in the space above the drain pan 40. In short, when the heat exchanger unit 42 of the present embodiment is used as a condenser, the upper first heat exchange area 500U and the upper second heat exchange area 600U, in which the flow velocity of the refrigerant is high, are disposed in a large amount in the space above the drain pan 40 in which the air speed of the air flow is high, and thus the indoor unit 4 having high heat exchange efficiency can be provided.

(3-2)

In the first heat exchanger 52 of the present embodiment, the area of the upper first heat exchange region 500U is larger than the area of the lower second heat exchange region 500L. Thus, the number of divisions of the refrigerant flow path in the lower first heat exchange area 500L is smaller than the number of divisions of the refrigerant flow path in the upper first heat exchange area 500U. Therefore, in the first heat exchanger 52, the refrigerant flow rate can be increased at the lower first heat exchange area 500L as compared with the upper first heat exchange area 500U.

Further, when the first heat exchanger 52 functions as a condenser, the supercooled region Sc is formed in the lower side first heat exchange region 500L. Therefore, in the indoor unit 4 of the present embodiment, the heat exchange efficiency can be improved as compared with the configuration in which the entire supercooled region Sc is disposed at a position higher than the upper end 40u of the wall portion 40w of the drain pan 40.

In addition, the same discussion as that for the first heat exchanger 52 holds true for the second heat exchanger 62. Therefore, the heat transfer rate of the lower second exchanger area 600L can be improved.

(3-3)

As described above, in the indoor unit 4 of the present embodiment, the casing 31 has the air outlet 36 at the lower side, and the indoor heat exchanger 42 is disposed so as to surround the centrifugal fan 41 in the casing 31. That is, as shown in fig. 16, the indoor heat exchanger 4 is disposed inside the casing 31 while being bent so as to surround the periphery of the indoor fan 41 in a plan view. Therefore, for example, in the ceiling-buried indoor unit 4, the heat exchange efficiency can be improved.

(3-4)

As described above, in the heat exchanger unit 42 of the present embodiment, since the plurality of

heat exchangers

52 and 62 are installed, the heat exchange efficiency can be improved. As shown in fig. 13, when the direction D1 of the refrigerant flow flowing through the first heat exchanger 52 and the direction D2 of the refrigerant flow flowing through the second heat exchanger 62 (upper second heat exchange region 600U) are arranged to be opposite to each other, the temperature deviation of the blown air is suppressed. Therefore, the heat exchanger unit 42 of the present embodiment can supply the blown air with a small temperature variation.

In the case where the heat exchanger unit 42 includes the plurality of

heat exchangers

52 and 62, it is preferable that at least a part of the supercooled region Sc of the heat exchanger (the first heat exchanger 52 in the example of fig. 13) disposed most downstream with respect to the indoor fan 41 among the

heat exchangers

52 and 62 be disposed at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40.

(4) Modification example

(4-1) modification 1A

In the above description, the heat exchanger unit 42 is used as the indoor heat exchanger, but the indoor heat exchanger of the present embodiment may be configured by a single heat exchanger. For example, as shown in fig. 17 and 18, the indoor heat exchanger 42 may be only the first heat exchanger 52 or the second heat exchanger 62. In the above configuration, if at least a part of the supercooled regions Sc1, Sc2 of the first heat exchanger 52 or the second heat exchanger 62 is disposed at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40, the heat exchange efficiency can be improved.

(4-2) modification 1B

In the above description, the heat exchanger unit 42 is used as the indoor heat exchanger, but the heat exchanger unit of the present embodiment may be configured by a combination of the

heat exchangers

52 and 62 having any configuration. For example, as another embodiment of the heat exchanger unit 42, a configuration shown in fig. 19 may be adopted. In the above configuration, if at least a part of the supercooled regions Sc1, Sc2 of the first heat exchanger 52 or the second heat exchanger 62 is disposed at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40, the heat exchange efficiency can be improved.

(4-3) modification 1C

In the indoor unit 4 of the present embodiment, when the indoor heat exchanger 42 is used as a condenser, at least a part of the supercooled region Sc may be disposed in the vicinity of the upper end 40u of the wall portion 40w of the drain pan 40. In short, in the indoor unit 4 of the present embodiment, it is not necessary to form the entire supercooled region Sc of the heat exchanger unit 42 at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40.

As shown in fig. 13, the inventors of the present invention have found that the wind speed locally increases near the upper end 40u of the wall portion 40w of the drain pan 40. Therefore, even if the supercooled region Sc is not formed entirely lower than the upper end 40u of the wall portion 40w of the drain pan 40, the supercooling degree of the refrigerant can be increased by forming the supercooled region Sc at least in the vicinity of the upper end 40 u.

In the indoor unit 4 of the present embodiment, when the indoor heat exchanger 42 is used as a condenser, at least a part of the supercooling region Sc may be disposed at a position over the upper end 40u of the wall portion 40w of the drain pan 40. With the above arrangement, the ratio of heat exchange between the liquid refrigerant and the air becomes high at the position across the upper end 40u of the wall portion 40w of the drain pan 40, and therefore the degree of supercooling of the refrigerant in the supercooling region Sc can be increased.

(4-4) modification 1D

In the heat exchanger unit 42 of the present embodiment, the upper side and the lower side are defined in the first heat exchanger 52 and the second heat exchanger 62, respectively, but the upper side and the lower side may be defined in the heat exchanger unit 42 of the present embodiment as a whole. Specifically, when the heat exchanger unit 42 is integrated such that the first heat exchanger 52 and the second heat exchanger 62 are connected by the connecting pipe, the connection port side connected to the gas-side connection pipe 6a is defined as "upper side", and the connection port side connected to the liquid-side connection pipe 5a is defined as "lower side". In this case, the area of the upper heat exchange region of the heat exchanger unit 42 is larger than the area of the lower heat exchange region. In summary, the indoor heat exchanger according to the present embodiment includes the following configurations: even if the area of the upper heat exchange region (500U or 600U) is not larger than the area of the lower heat exchange region (500L or 600L) in the single first heat exchanger 52 or second heat exchanger 62, the area of the upper heat exchange region is larger than the area of the lower heat exchange region as a whole. For example, as shown in fig. 20, the indoor heat exchanger of the present embodiment is integrated such that the first heat exchanger 52 and the second heat exchanger 62 are connected by the connecting

pipes

427 and 428. In the example of fig. 20, the supercooled regions Sc1 and Sc2 are formed only in the first heat exchanger 52, but the heat exchanger unit 42 as a whole is configured in such a manner that the area of the upper heat exchange region is larger than the area of the lower heat exchange region as defined above.

In the embodiment of modification 1D, when the heat exchanger unit 42 is used as a condenser, the supercooled region Sc is preferably formed in the first heat exchanger 52 on the upstream side of the second heat exchanger 62 on the downstream side.

< second embodiment >

In the following, the same portions as those already described are denoted by the same reference numerals, and redundant description thereof is omitted. Note that, in this embodiment, a symbol S may be added to distinguish from other embodiments.

The air conditioner 1S according to the second embodiment of the present invention is different from the air conditioner 1 according to the first embodiment in the specific form of the indoor unit 4S. Specifically, the indoor unit 4S of the present embodiment has a structure of a type called a duct type.

Fig. 21 is a schematic cross-sectional view of the duct-type indoor unit 4S of the present embodiment. In the duct-type indoor unit 4S, the casing 31S has a blow-out port 36S on the side. In the duct-type indoor unit 4S, a heat exchanger chamber 31H and an air blowing chamber 31S are formed in the casing 31S, the heat exchanger chamber 31H communicating with the air outlet 36S, and the air blowing chamber 31S communicating with the heat exchanger chamber 31H through the partition plate B. The indoor heat exchanger 42 is provided in the heat exchanger chamber 31H. The indoor fan 41 is provided in the blowing chamber 31S. Here, the indoor heat exchanger 42 has the same structure as that of the first embodiment.

In the indoor unit 4S having the above-described configuration, when at least a part of the supercooling region Sc of the indoor heat exchanger 42S is disposed at a position lower than the upper end 40Su of the wall portion 40Sw of the drain pan 40S, the heat exchange efficiency can be improved as compared with the configuration in which the entire supercooling region Sc is disposed at a position higher than the upper end 40Su of the wall portion 40Sw of the drain pan 40S.

In the present embodiment, the structure in which the plurality of flat multi-hole tubes are "arranged in the vertical direction" in the indoor heat exchanger 42S does not mean that the upper surfaces and/or the lower surfaces of the flat multi-hole tubes are arranged in the vertical direction so as to be along the horizontal direction, but means that the upper surfaces and/or the lower surfaces of the flat multi-hole tubes are arranged in the vertical direction so as to be along the direction inclined from the horizontal direction as shown in fig. 21. As long as the heat exchanger or the like having the above-described structure is used, another type of heat exchanger can be mounted as it is, and the heat exchanger or the like can be easily manufactured.

However, the structure of the heat exchanger 42S of the present embodiment is not limited to this, and a plurality of flat multi-hole tubes may be arranged vertically so as to extend in a direction inclined from the vertical direction as shown in fig. 22. As long as the heat exchanger or the like having the above-described configuration is used, the air flow having a high flow velocity can be caused to pass through the heat exchange region, and the heat exchange efficiency between the refrigerant and the air can be improved.

The indoor heat exchanger 42S may be a heat exchanger unit including a plurality of heat exchangers, or may be a single heat exchanger. This point is the same as in the first embodiment. That is, when the heat exchanger unit 42S including the plurality of heat exchangers 52S and 62S is provided, the heat exchange efficiency can be improved as compared with a single heat exchanger. Further, when the direction D1 of the refrigerant flow flowing through the first heat exchanger 52S and the direction D2 of the refrigerant flow flowing through the second heat exchanger 62S are opposite to each other, the temperature deviation of the blown air can be suppressed.

In addition, when the heat exchanger unit 42 includes a plurality of heat exchangers, it is preferable that the heat exchanger on the upstream side form a supercooled region rather than the heat exchanger on the downstream side. Preferably, the supercooling region of the upwind heat exchanger is disposed at a position higher than the upper end 40u of the wall portion 40w of the drain pan 40 than the supercooling region of the downwind heat exchanger.

< other embodiments >

While the embodiments and the modifications of the present invention have been described above with reference to the drawings, the specific configurations are not limited to the embodiments and the modifications, and may be changed without departing from the spirit of the present invention. For example, in the above-described embodiment and the modifications thereof, an example in which the present invention is applied to a ceiling-embedded type and duct type air conditioning apparatus has been described, but the present invention is not limited thereto, and the present invention is also applicable to an air conditioning apparatus called a ceiling-suspended type in which the entire apparatus is disposed below a ceiling.

Description of the symbols

4 indoor units (air conditioning indoor units);

4S indoor unit (air-conditioning indoor unit);

31a housing;

31S outer shell;

a 31H heat exchanger chamber;

a 31W air supply chamber;

36 air outlets;

a 36S air outlet;

40a drain pan;

40S, a drain pan;

the bottom of the 40t drain pan;

a wall portion of a 40w drain pan;

the upper end of the wall of the 40u drain pan;

41 indoor fan (fan);

41S indoor fan (fan);

42 indoor heat exchanger, heat exchanger unit (heat exchanger);

a 42S indoor heat exchanger, a heat exchanger unit (heat exchanger);

52 a first heat exchanger (heat exchanger);

62 a second heat exchanger (heat exchanger);

500U upper side first heat exchange area (upper side heat exchange area);

a 500L lower side first heat exchange area (lower side heat exchange area);

600U upper side second heat exchange area (upper side heat exchange area);

a 600L lower side second heat exchange area (lower side heat exchange area);

b, a partition plate;

a Sc supercooling region;

a Sc1 supercooling region;

a Sc2 supercooling region;

documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-099609.

Claims

1. An air conditioning indoor unit (4, 4s) comprising:

a housing (31, 31S) provided indoors;

a fan (41, 41S) disposed within the housing;

a heat exchanger (42, 42S, 52, 62) disposed within the housing and arranged in an up-down arrangement, the heat exchanger having a plurality of flat perforated tubes; and

a drain pan (40, 40S) disposed below the heat exchanger,

the indoor unit of an air conditioner is characterized in that,

the heat exchanger is divided into an upper heat exchange area (500U, 600U) and a lower heat exchange area (500L, 600L),

when the heat exchanger is used as a condenser, a supercooling region (Sc, Sc1, Sc2) which supercools a refrigerant flowing inside the heat exchanger and is constituted by one or more flat perforated tubes is formed in the lower heat exchange region,

the drain pan has a bottom portion (40t) provided below the heat exchanger and a wall portion (40w) provided upright from the bottom portion and provided on a leeward side of the heat exchanger,

at least a part of the supercooling region is disposed at a position lower than an upper end (40u) of the wall portion of the drain pan.

2. An indoor unit of an air conditioner according to claim 1,

the area of the upper heat exchange area is larger than the area of the lower heat exchange area.

3. An indoor unit of an air conditioner according to claim 1 or 2,

at least a portion of the supercooling region is disposed in the vicinity of an upper end of a wall portion of the drain pan.

4. An indoor unit of an air conditioner according to claim 1 or 2,

at least a part of the supercooling region is disposed at a position across an upper end of a wall portion of the drain pan.

5. An indoor unit of an air conditioner according to claim 1 or 2,

the housing has a blow-out opening (36) at a lower portion,

the fan is a centrifugal fan which is,

the heat exchanger is configured to enclose the centrifugal fan within the housing.

6. An indoor unit of an air conditioner according to claim 1 or 2,

the casing has an outlet (36S) on the side,

a heat exchanger chamber (31H) and an air blowing chamber (31W) are formed in the casing, the heat exchanger chamber is communicated with the air outlet, the air blowing chamber is communicated with the heat exchanger chamber through a partition plate (B),

the heat exchanger is disposed in the heat exchanger chamber,

the fan is arranged in the air supply chamber.

7. An indoor unit of an air conditioner according to claim 1 or 2,

the heat exchanger is a heat exchanger unit composed of a plurality of heat exchangers.

8. An indoor unit of an air conditioner according to claim 7,

at least a part of a supercooling region of the heat exchanger disposed most downwind with respect to the fan in the heat exchanger unit is disposed at a position lower than an upper end of the wall portion of the drain pan.