JPWO2018180279A1 - Air conditioning indoor unit - Google Patents

Abstract

Provide an air conditioning indoor unit with high heat exchange performance. In the air-conditioning indoor unit (4), when the heat exchanger unit (42) is used as a condenser, the heat exchanger unit ( At least a part of the subcooling area (Sc1, Sc2) of 42) is arranged.

Description

  The present invention relates to an air-conditioning indoor unit.

  Conventionally, an air-conditioning indoor unit that blows out conditioned air has been used. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-099609) discloses an air-conditioning indoor unit equipped with a fin-and-tube heat exchanger.

  In recent years, it has been studied to mount a microchannel heat exchanger using a flat multi-hole tube in an air conditioning indoor unit. In a heat exchanger using a flat multi-hole tube, heat exchange regions in which the number of divisions of the refrigerant channel is different may be formed. Further, in the air-conditioning indoor unit, the wind speed distribution of the airflow by the centrifugal fan may fluctuate greatly depending on the position due to the influence of the internal structure and the like. Therefore, in an air-conditioning indoor unit equipped with a heat exchanger using a flat multi-hole tube, the heat exchange performance may be significantly reduced depending on the internal wind speed distribution and the position where the heat exchanger is arranged.

  An object of the present invention is to provide an air-conditioning indoor unit having high heat exchange performance.

  An air conditioning indoor unit according to a first aspect of the present invention is a heat exchanger including a casing installed in a room, a fan provided in the casing, and a plurality of flat multi-hole tubes arranged in the casing and arranged vertically. And a drain pan provided below the heat exchanger. Here, the heat exchanger is divided into an upper heat exchange area and a lower heat exchange area. Further, when the heat exchanger is used as a condenser, a subcooling region formed of one or more flat multi-hole tubes for supercooling a refrigerant flowing therein is formed in the lower heat exchange region. The drain pan has a bottom provided below the heat exchanger, and a wall standing upright from the bottom and provided on the leeward side of the heat exchanger. And in this air-conditioning indoor unit, at least a part of the subcooling area is arranged at a position lower than the upper end of the wall of the drain pan.

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

  In the present invention, the term "indoor" is used to distinguish it from other rooms, and is used to include not only an indoor space defined by a wall surface but also, for example, a space behind an indoor ceiling.

  Further, in the present invention, a configuration in which a plurality of flat multi-hole tubes are “lined up and down” means an arbitrary configuration in which the center of gravity of each flat multi-hole tube is lined up and down. Therefore, in this configuration, the upper surface and / or the lower surface of each flat multi-hole tube are not limited to those vertically arranged in the horizontal direction, and the upper surface and / or the lower surface of the flat multi-hole tube are vertically moved in the direction inclined from the horizontal direction. Including those lined up. Further, in this configuration, the plurality of flat multi-hole tubes are not limited to those vertically arranged in the vertical direction, but include those vertically arranged in the direction inclined from the vertical direction.

  An air conditioning indoor unit according to a second aspect of the present invention is the air conditioning indoor unit according to the first aspect, wherein 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, since the area of the upper heat exchange area is larger than the area of the lower heat exchange area, an air-conditioning indoor unit having high heat exchange efficiency can be provided.

  An air conditioning indoor unit according to a third aspect of the present invention is the air conditioning indoor unit according to the first aspect or the second aspect, wherein at least a part of the subcooling region is arranged near an upper end of a wall of the drain pan. With such a configuration, a heat exchanger having a large heat exchange area between the gas refrigerant and the air can be disposed above the drain pan.

  An air-conditioning indoor unit according to a fourth aspect of the present invention is the air-conditioning indoor unit according to any of the first to third aspects, wherein at least a part of the supercooling region is arranged at a position straddling the upper end of the wall of the drain pan. You. With such a configuration, a heat exchanger having a high rate of heat exchange with the gas refrigerant can be arranged 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 of the first to fourth aspects, wherein the casing has a suction port below, the fan is a centrifugal fan, and the heat exchanger is It is disposed so as to surround the centrifugal fan in the casing.

  In the air-conditioning indoor unit according to the fifth aspect, for example, in an air-conditioning indoor unit embedded in a ceiling, 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 aspect to the fourth aspect, wherein the casing has a suction port on a side and a partition plate is provided inside the casing. Here, the partition plate is a member for forming a heat exchanger room in which the heat exchanger communicates with the suction port and in which a fan is arranged in communication with the heat exchanger room.

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

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

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

  The air-conditioning indoor unit according to an eighth aspect of the present invention is the air-conditioning indoor unit according to the seventh aspect, wherein at least a part of a subcooling area of a heat exchanger disposed most leeward to a fan among heat exchanger units Is disposed at a position lower than the upper end of the wall 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 a plurality of heat exchangers is mounted.

  In the air conditioning indoor unit according to the first aspect, the heat exchange efficiency can be improved.

  The air conditioning indoor unit according to the second aspect can provide an air conditioning indoor unit having high heat exchange efficiency.

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

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

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

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

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

  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 a plurality of heat exchangers is mounted.

It is a schematic structure figure of air conditioner 1 concerning a 1st embodiment of the present invention. It is an external appearance perspective view of the indoor unit 4 of the ceiling-mounted air conditioner according to the embodiment. It is a schematic side sectional view of the indoor unit 4 of the ceiling-mounted air conditioner according to the embodiment. FIG. 4 is a schematic plan view showing a state in which a ceiling plate 33 of the indoor unit 4 embedded in the ceiling according to the embodiment is removed. It is a partially enlarged view for explaining the configuration of the dress water receiving groove 40i according to the same embodiment. FIG. 3 is a schematic perspective view of a heat exchanger 42a used in the heat exchanger unit 42 according to the same embodiment. FIG. 3 is a schematic vertical sectional view of a heat exchanger used in the heat exchanger unit 42 according to the same embodiment. It is a schematic perspective view which shows the other example of the heat exchanger 42a used in the heat exchanger unit 42 concerning the embodiment. It is a schematic diagram which shows the structure of the heat exchanger unit 42 concerning the embodiment. It is a schematic diagram which shows the structure of the heat exchanger unit 42 concerning the embodiment. It is a schematic diagram which shows the structure of the 1st heat exchanger 52 which concerns on the embodiment. It is a schematic diagram which shows the structure of the 2nd heat exchanger 62 which concerns on the embodiment. It is a figure for explaining the internal state when the heat exchanger unit 42 concerning the embodiment is used as a condenser. It is a figure which shows the wind speed distribution between the drain pan 40 and the inner wall of the casing 31 which concern on the embodiment. It is a figure which shows the streamline distribution of the airflow between the drain pan 40 and the inner wall of the casing 31 which concern on the embodiment. It is a schematic diagram which shows the planar shape of the heat exchanger unit 42 concerning the embodiment. It is a mimetic diagram showing the composition of the indoor heat exchanger concerning modification 1A. It is a mimetic diagram showing the composition of the indoor heat exchanger concerning modification 1A. It is a mimetic diagram showing the example of the heat exchanger unit concerning modification 1B. It is a mimetic diagram showing the example of the heat exchanger unit concerning modification 1D. It is an outline sectional view of duct type indoor unit 4S concerning a 2nd embodiment of the present invention. It is a schematic diagram which shows the modification of the indoor unit 4S which concerns on the same embodiment.

  Hereinafter, embodiments of the air-conditioning apparatus according to the present invention and modifications thereof will be described with reference to the drawings. Note that the specific configuration of the air-conditioning apparatus according to the present invention is not limited to the following embodiments and modifications thereof, and can be changed without departing from the spirit of the invention.

<First Embodiment>
(1) Outline of air conditioner (1-1) Basic configuration of air conditioner FIG. 1 is a schematic configuration diagram of an air conditioner 1 according to a first embodiment of the present invention.

  The air conditioner 1 is a device capable of performing cooling and heating of a room such as a building 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 a liquid refrigerant communication pipe 5 and a gas refrigerant communication pipe 6. Various operations of the air conditioner 1 are controlled 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.

  Note that, here, a pair-type air conditioner 1 in which one indoor unit 4 is connected to one outdoor unit 2 is illustrated, but the air conditioner 1 according to the present embodiment has one unit. It may be a multi-type air conditioner in which a plurality of indoor units are connected to the outdoor unit.

(1-2) Basic operation of air conditioner Next, a basic operation of the air conditioner 1 will be described. The air-conditioning apparatus 1 can perform a cooling operation and a heating operation as a basic operation. In addition, the air-conditioning apparatus 1 can 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 switching valve 22 becomes the refrigerant circuit 10 indicated by the solid line in FIG. In the refrigerant circuit 10, the 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 outdoor heat exchanger 23 through the four-way switching valve 22. The high-pressure gas refrigerant sent to the outdoor heat exchanger exchanges heat with outdoor air in the outdoor heat exchanger 23 and condenses. Thus, the high-pressure gas refrigerant becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is reduced in pressure in 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 through the liquid refrigerant communication pipe 5 and the liquid-side connection pipe 5a. This refrigerant exchanges heat with the air blown 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 through the gas-side connection pipe 6a, the gas refrigerant communication pipe 6, and the four-way switching valve 22.

(1-2-2) Heating Operation In the heating operation, the four-way switching valve 22 becomes the refrigerant circuit 10 indicated by the broken line in FIG. In the refrigerant circuit 10, the 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 through the four-way switching valve 22, the gas refrigerant communication pipe 6, and the gas-side connection pipe 6a. The high-pressure gas refrigerant sent to the indoor heat exchanger 42 exchanges heat with the air blown from the indoor fan 41 and condenses. Thus, the high-pressure gas refrigerant becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is sent to the expansion valve 24 through the liquid-side connection pipe 5a and the liquid refrigerant communication pipe 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. Then, the refrigerant exchanges heat with outdoor air in the outdoor heat exchanger 23 and evaporates. Thereby, the refrigerant sent to the outdoor heat exchanger 23 becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant is sent again to the compressor 21 through the four-way switching valve 22.

(2) Configuration of Indoor Unit The air conditioner according to this embodiment has the following configuration in addition to the basic configuration described above.

  In the present embodiment, the term “indoor” is used to distinguish it from other rooms, and is used to include not only the indoor space defined by the wall surface but also, for example, the space behind the indoor ceiling. .

(2-1) Basic Configuration of Indoor Unit The indoor unit 4 is installed indoors and forms 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 8a.

  The indoor fan 41 sucks indoor air into the indoor unit 4. Thereby, the indoor air and the refrigerant can exchange heat in the indoor heat exchanger 42. In addition, the indoor fan 41 supplies the indoor air that has undergone heat exchange in the indoor heat exchanger 42 to the room as supply air. As the indoor fan 41, a centrifugal fan, a multi-blade fan, or the like is used. The indoor fan 41 is driven by an indoor fan motor whose number of revolutions can be controlled.

  The indoor heat exchanger 42 functions as a refrigerant “evaporator” during cooling operation to cool indoor air, and functions as a refrigerant “condenser” (radiator) during heating operation to heat room air. The indoor heat exchanger 42 is connected to the liquid refrigerant communication pipe 5 and the gas refrigerant communication pipe 6. Further details of 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 has 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. Further, the indoor control unit 8a communicates a control signal with a remote controller (not shown) for individually operating the indoor unit 4, and controls a control signal with the outdoor control unit 8b via a transmission line. Or to communicate.

  In addition, the indoor unit 4 is provided with various sensors. Thereby, the temperature of the refrigerant in the indoor heat exchanger 42, the temperature of the indoor air drawn into the indoor unit 4, and the like are detected.

(2-2) Indoor Unit of Recessed Ceiling Type The indoor unit 4 according to the present embodiment can adopt a configuration of a type called a recessed ceiling type. FIG. 2 is an external perspective view of the indoor unit 4 embedded in a ceiling according to the present embodiment. FIG. 3 is a schematic sectional view of the indoor unit 4 embedded in the ceiling according to the present embodiment. Here, FIG. 3 shows an AOA cross section in FIG. 4 described later. FIG. 4 is a schematic plan view showing a state where the top plate 33 of the indoor unit 4 embedded in a ceiling according to the present embodiment is removed.

  The ceiling embedded indoor unit houses an indoor fan 41 and an indoor heat exchanger 42 in a casing 31. A drain pan 40 is attached to a lower portion of the casing 31.

(2-2-1) Casing The casing 31 houses various constituent devices inside. The casing 31 mainly has a casing main body 31a and a decorative panel 32 arranged below the casing main body 31a. As shown in FIG. 3, the casing body 31a is disposed on a ceiling U in a room to which conditioned air is provided. An opening is formed in the ceiling U, and the casing body 31a is inserted into the opening of the ceiling U. Then, the decorative panel 32 is arranged so as to be fitted into the opening of the ceiling U.

  As shown in FIGS. 3 and 4, the casing body 31a is a box-shaped body having a substantially octagonal lower surface in which long sides and short sides are alternately formed in a plan view. Specifically, the casing main body 31a has a substantially octagonal top plate 33 in which long sides and short sides are formed alternately and continuously, and a side plate 34 extending downward from a peripheral portion of the top plate 33. I have. The side plates 34 include 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 penetrate, so that the refrigerant communication pipes 5, 6 can be connected to the indoor heat exchanger 42.

  As shown in FIGS. 2 to 4, the decorative panel 32 is a plate-like body having a substantially quadrangular shape in plan view, and mainly includes a panel main body 32 a fixed to a lower end portion of the casing main body 31 a. The panel main body 32a has a suction port 35 at a substantially center thereof for sucking air in the air-conditioned room, and an air outlet 36 formed to surround the periphery of the suction port 35 in plan view and for blowing air into the air-conditioned room. The suction port 35 is a substantially rectangular opening. The suction port 35 is provided with a suction grill 37 and a filter 38 for removing dust in the air sucked from the suction port 35. The outlet 36 is a substantially quadrangular annular opening. The outlet 36 is provided with horizontal flaps 39a, 39b, 39c, 39d for adjusting the direction of air blown into the air-conditioned room so as to correspond to each side of the square of the panel body 32a.

(2-2-2) Drain Pan 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 on a lower part of the casing main body 31a. In the drain pan 40, blow holes 40a, 40b, 40c, 40d, 40e, 40f, 40g, a suction hole 40h, and a drain water receiving groove 40i are formed. The outlets 40 a to 40 g are formed so as to communicate with the outlet 36 of the decorative panel 32. The suction hole 40h is formed so as 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. Further, a bell mouth 41c for guiding the air sucked from the suction port 35 to the impeller 41b of the indoor fan is disposed in the suction hole 40h of the drain pan 40.

  As shown in FIG. 5, the dress water receiving groove 40i has a bottom 40t provided below the indoor heat exchanger 42, and a wall 40w provided upright from the bottom 40t and provided on the leeward side of the indoor heat exchanger 42. And By the way, when used as a condenser, the indoor heat exchanger 42 forms a supercooling region Sc composed of one or more flat multi-hole tubes for supercooling the refrigerant flowing inside. The indoor unit 4 according to the present embodiment is configured such that at least a part of the subcooling area Sc of the indoor heat exchanger 42 is arranged at a position lower than the upper end 40u of the wall 40w of the drain pan 40. In addition, as such a configuration, all of the subcooling region Sc is disposed at a position lower than the upper end 40u of the wall portion 40w of the drain pan 40, and part of the subcooling region Sc is disposed near the upper end 40u. And a configuration in which a part of the supercooling region Sc is disposed at a position straddling the upper end 40u.

(2-2-3) Indoor Fan The indoor fan 41 is configured 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 the air out of the casing main body 31a through the outlet 36 of the decorative panel 32. Specifically, the indoor fan 41 has a fan motor 41a provided at the center of the top plate 33 of the casing main body 31a, and an impeller 41b connected to the fan motor 41a and driven to rotate. The impeller 41b has turbo blades. By the impeller 41b, air is sucked into the inside of the impeller 41b from below, and the sucked air is blown toward the outer peripheral side of the impeller 41b in plan view.

(2-2-4) Indoor Heat Exchanger The indoor heat exchanger 42 is bent inside the casing 31 so as to surround the indoor fan 41 in plan view. The liquid side of the indoor heat exchanger 42 is connected to the liquid refrigerant communication pipe 5 via the liquid side connection pipe 5a. The gas side of the indoor heat exchanger 42 is connected to the gas refrigerant communication pipe 6 via the gas side connection pipe 6a. The indoor heat exchanger 42 functions as a refrigerant evaporator during the cooling operation and functions as a refrigerant condenser during the heating operation. Thereby, the indoor heat exchanger 42 performs heat exchange with the air blown out from the indoor fan 41, cools the air during the cooling operation, and heats the air during the heating operation.

(2-2-4-1) Basic Configuration of Heat Exchanger FIG. 6 is a schematic perspective view showing a basic configuration of a heat exchanger 42 a used in the indoor heat exchanger 42. In FIG. 6, illustration of a refrigerant pipe, a communication pipe, and the like is omitted. FIG. 7 is a schematic longitudinal sectional view of the heat exchanger used in the heat exchanger 42a.

  The heat exchanger 42a is a plug-in fin-type heat exchanger mainly including a heat transfer tube 421 formed of a flat multi-hole tube, a large number of fins 422, and two headers 423 and 424.

  The heat transfer tube 421 is realized by a flat multi-hole tube. Here, both ends of the heat transfer tube 421 are connected to each of the headers 423 and 424. In addition, the heat transfer tubes 421 are arranged in a plurality of stages at intervals with the plane portions facing up and down. Specifically, the heat transfer tube 421 has upper and lower flat portions serving as heat transfer surfaces, and a number of small coolant channels 421a through which the coolant flows. As the coolant passage 421a, a coolant having a small inner diameter of 1 mm or less or a polygonal small passage hole having a sectional area equivalent to the circle is used. Note that the heat transfer tube 421 is formed of aluminum or an aluminum alloy.

  The fins 422 are inserted into a plurality of stages of the heat transfer tubes 421 arranged between the headers 423 and 424. Specifically, the fin 422 is formed with a plurality of notches 422a extending horizontally and elongated. The shape of the notch 422a substantially matches the outer shape of the cross section of the heat transfer tube 421. Therefore, by engaging the notch 422 a with the outer surface of the heat transfer tube 421, the heat transfer tube 421 can be inserted so as to be in contact therewith. The fins 422 are formed of aluminum or an aluminum alloy. In addition, the fin 422 can take various shapes, and for example, may have a waveform as shown in FIG.

  The two headers 423 and 424 each have a function of supporting the heat transfer tube 421, a function of guiding the refrigerant to the refrigerant flow path 421a of the heat transfer tube 421, and a function of collecting the refrigerant flowing out of the refrigerant flow path 421a. It has.

(2-2-4-2) Configuration of Heat Exchanger Unit The indoor heat exchanger 42 according to the present embodiment is configured by a heat exchanger unit in which a plurality of the above-described heat exchangers 42a are combined. In the following description, for the sake of convenience, the heat exchanger unit will be described with the reference numeral 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 that of the above-described heat exchanger 42a, but will be described by replacing the reference numerals for convenience. Specifically, in the following description, the first numeral of the reference numeral is “4” when describing the configuration of the entire heat exchanger unit, and the first numeral of the reference numeral is “5” when describing the first heat exchanger 52. , And the description of the second heat exchanger 62 will be made by replacing the first numeral of the code with “6”. For example, the heat transfer tube of the first heat exchanger 52 or the second heat exchanger 62 has the same configuration as the heat transfer tube 421 described above, but is not the reference numeral 421 but the reference numeral 521 or the reference numeral 621, respectively. The description will be made with "."

  FIG. 9 is a schematic diagram illustrating a configuration of the heat exchanger unit 42 according to the present embodiment. The heat exchanger unit 42 is arranged on the leeward side of the airflow by the indoor fan (fan) 41 and on the leeward side of the airflow by the indoor fan 41 in the first heat exchanger 52. And a second heat exchanger 62 that is arranged in a manner similar to the above. Here, the first direction D1 of the refrigerant flow from the first header 523 to the second header 524 of the first heat exchanger 52 and the upper third header 523U of the second heat exchanger 62 to the upper fourth header 624U. It is assumed that the second direction D2 of the refrigerant flow is opposed. In FIG. 9, for convenience of explanation, the first heat exchanger 52 and the second heat exchanger 62 are illustrated separately from each other, but they are arranged close enough to function integrally. (See FIG. 10).

  The first heat exchanger 52 is a first flat tube including a first header 523 and a second header 524, and a plurality of flat multi-hole tubes (heat transfer tubes) connected to the first header 523 and the second header 523, respectively. And a group 500. In the first flat tube group 500, a plurality of flat multi-hole tubes are vertically arranged. Further, in the first flat tube group 500, as shown in FIG. 11, one or more flat multi-hole tubes on the upper side form the upper first heat exchange region 500U, and one or more flat multi-hole tubes on the lower side form the lower part. The first side heat exchange region 500L is formed.

  As shown in FIG. 11, the first header 523 has an upper first header 523U connected to the upper first heat exchange area 500U, and a lower first header 523L connected to the lower first heat exchange area 500L. . A gas-side connection pipe 6a (gas refrigerant pipe) through which gaseous refrigerant flows is connected to the upper first header 523U. The connection pipes 525 and 526 are connected to the lower first header 523L. Thus, the upper second header 524U and the lower first header 523L are connected. The inner space of the first header 523 is vertically divided (here, two) by a partition plate 523a. As a result, the upper first header 523U and the lower first header 523L are configured not to communicate internally.

  As shown in FIG. 11, the second header 524 has an upper second header 524U connected to the upper first heat exchange area 500U and a lower second header 524L connected to the lower first heat exchange area 500L. . The connection pipes 525 and 526 are connected to the upper second header 524U. As a result, the upper second header 524U and the lower first header 523L are connected. The lower second header 524L is connected to a liquid-side connection pipe 5a through which a liquid refrigerant flows. The inner space of the second header 524 is vertically divided (here, two) by a partition plate 524a. Thereby, the upper second header 524U and the lower second header 524L are configured not to communicate internally.

  The connection pipes 525 and 526 are pipes that connect the upper second header 524U and the lower first header 523L. In addition, a temperature measuring device for measuring the temperature of the refrigerant is attached to the connection pipes 525 and 526.

  The second heat exchanger 62 includes a third header 623 and a fourth header 624, and a second flat tube group 600 including a plurality of flat multi-hole tubes connected to the third header 623 and the fourth header 624, respectively. Having. In the second flat tube group 600, a plurality of flat multi-hole tubes are vertically arranged. In the second flat tube group 600, as shown in FIG. 12, the upper one or more flat multi-hole tubes form the upper second heat exchange region 600U, and the lower one or more flat multi-hole tubes are lower. The side second heat exchange region 600L is formed.

  As shown in FIG. 12, the third header 623 has an upper third header 623U connected to the upper second heat exchange area 600U, and a lower third header 623L connected to the lower second heat exchange area 600L. . More specifically, the inner space of the third header 623 is vertically divided (here, two) by a partition plate 623a. The upper space 623g of the partition plate 623a connects to the upper second heat exchange region 600U, and the lower space 623h of the partition plate connects to the lower second heat exchange region 600L. The gas side connection pipe 6a is connected to the upper third header 623U. The liquid side connection pipe 5a is connected to the lower third header 623L.

  As shown in FIG. 12, the fourth header 624 includes 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. . More specifically, the inner space of the fourth header 624 is vertically divided (here, two) by a partition plate 624a. The upper space 624i of the partition plate 624a connects to the upper second heat exchange area 600U, and the lower space 624j of the partition plate 624a connects to the lower second heat exchange area 600L. In addition, the fourth header 624 has a “return portion” that connects the upper fourth header 624U and the lower fourth header 624L and that returns the refrigerant flowing from the third header 623 to the third header 623. 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 folded portion. Note that a temperature measuring device for measuring the temperature of the refrigerant is attached to the connecting pipe 625.

(3) Features (3-1)
In the heat exchanger unit 42 as described above, the first heat exchanger 52 forms the upper first heat exchange area 500U and the lower first heat exchange area 500L, and the upper first heat exchange area 500U has a gas-side connection pipe. A connection port with the liquid side connection pipe 5a is disposed in the lower first heat exchange area 500L. Also, the second heat exchanger 62 forms an upper second heat exchange area 600U and a lower second heat exchange area 600L, and a connection port with the gas-side connection pipe 6a is arranged in the upper second heat exchange area 600U, A connection port with the liquid side connection pipe 5a is arranged 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 area is as shown in FIG. 13, and the supercooled areas Sc1 and Sc2 composed of one or more flat multi-hole tubes are located on the lower side. It is formed in the first heat exchange area 500L and the lower second heat exchange area 600L. In FIG. 13, hatching in regions Sc1 and Sc2 indicates a supercooling region in which the refrigerant is supercooled, and hatching in regions Sh1 and Sh2 indicates a superheating region in which the refrigerant is overheated.

  Here, in the indoor unit 4 (air conditioning indoor unit) according to the present embodiment, at least a part of the supercooling regions Sc1 and Sc2 of the heat exchanger unit 42 is located at a position lower than the upper end 40u of the wall 40w of the drain pan 40. Be placed. Therefore, in the indoor unit 4 according to the present embodiment, it is possible to improve the heat exchange efficiency as compared with the configuration in which the entire subcooling region Sc is arranged at a position higher than the upper end 40u of the wall portion 40w of the drain pan 40. it can.

  Supplementally, according to the study by the present inventors, in the indoor unit 4, the flow velocity (wind speed) of the air flow in the space above the drain pan 40 increases. Specifically, the wind speed distribution between the drain pan 40 and the inner wall of the casing 31 is represented as a graph shown in FIG. Here, in FIG. 14, the vertical axis indicates the vertical position inside the casing 31, and the horizontal axis indicates the wind speed. As can be seen from FIG. 14, in the indoor unit 4, the wind speed increases in the space above the drain pan 40. The streamline distribution of the air flow between the drain pan 40 and the inner wall of the casing 31 is represented as shown in FIG.

  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) in which heat exchange between the liquid refrigerant and the air is performed are formed on the wall portion 40w of the drain pan 40. The heat exchange areas (mainly the upper heat exchange areas 500U and 600U) in which heat exchange between the gas refrigerant and the air is performed are arranged in the space above the drain pan 40. Will be. In short, when the heat exchanger unit 42 according to the present embodiment is used as a condenser, the upper first heat exchange region 500U and the upper second heat exchanger 500 in which the flow rate of the refrigerant is fast are provided in the space above the drain pan 40 in which the air flow is fast. A configuration in which a large number of exchange areas 600U are arranged can provide an indoor unit 4 with high heat exchange efficiency.

(3-2)
In the first heat exchanger 52 according to the present embodiment, the area of the upper first heat exchange area 500U is larger than the area of the lower second heat exchange area 500L. Thereby, the number of divisions of the refrigerant flow path of the lower first heat exchange area 500L is smaller than the number of divisions of the refrigerant flow path of the upper first heat exchange area 500U. Therefore, in the first heat exchanger 52, the flow rate of the refrigerant can be higher in the lower first heat exchange area 500L than in the upper first heat exchange area 500U.

  When the first heat exchanger 52 is used as a condenser, a subcooling region Sc is formed in the lower first heat exchange region 500L. Therefore, in the indoor unit 4 according to the present embodiment, the heat exchange efficiency can be improved as compared with a configuration in which all the subcooling regions Sc are arranged at a position higher than the upper end 40u of the wall 40w of the drain pan 40. it can.

  Note that the same discussion holds for the second heat exchanger 62 as for the first heat exchanger 52. Therefore, the heat transfer coefficient in the lower second heat exchanger region 600L can be improved.

(3-3)
As described above, in the indoor unit 4 according to the present embodiment, the casing 31 has the outlet 36 below, and the indoor heat exchanger 42 is arranged so as to surround the centrifugal fan 41 in the casing 31. That is, as shown in FIG. 16, the indoor unit 4 is bent so as to surround the indoor fan 41 in a plan view and disposed inside the casing 31. Therefore, for example, in the indoor unit 4 embedded in the ceiling, the heat exchange efficiency can be improved.

(3-4)
As described above, in the heat exchanger unit 42 according to the present embodiment, since the heat exchangers are mounted from the plurality of heat exchangers 52 and 62, the heat exchange efficiency can be improved. As shown in FIG. 13, the direction D1 of the refrigerant flow flowing inside the first heat exchanger 52 and the direction D2 of the refrigerant flow flowing inside the second heat exchanger 62 (upper second heat exchange area 600U). When they are arranged so as to face each other, temperature unevenness in the blown air is suppressed. Therefore, the heat exchanger unit 42 according to the present embodiment can provide blown air with less temperature unevenness.

  When the heat exchanger unit 42 has a plurality of heat exchangers 52 and 62, among the heat exchangers 52 and 62, the heat exchanger that is arranged most leeward with respect to the indoor fan 41 (see FIG. 13). In the example, it is preferable that at least a part of the subcooling region Sc of the first heat exchanger 52) is disposed at a position lower than the upper end 40u of the wall 40w of the drain pan 40.

(4) Modification (4-1) Modification 1A
In the above description, the heat exchanger unit 42 has been described as the indoor heat exchanger, but the indoor heat exchanger according to the present embodiment may be configured by a single heat exchanger. For example, as shown in FIGS. 17 and 18, the indoor heat exchanger 42 may have a configuration including only the first heat exchanger 52 or the second heat exchanger 62. Even with such a configuration, at least a part of the supercooling regions Sc1 and 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 40w of the drain pan 40. If so, the heat exchange efficiency can be improved.

(4-2) Modification 1B
In the above description, the heat exchanger unit 42 has been described as the indoor heat exchanger. However, the heat exchanger unit according to the present embodiment is configured by a combination of the heat exchangers 52 and 62 having an arbitrary configuration. Is also good. For example, another configuration of the heat exchanger unit 42 may be a configuration as shown in FIG. Even with such a configuration, at least a part of the supercooling regions Sc1 and 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 40w of the drain pan 40. If so, the heat exchange efficiency can be improved.

(4-3) Modification 1C
In the indoor unit 4 according to the present embodiment, when the indoor heat exchanger 42 is used as a condenser, at least a part of the subcooling region Sc is arranged near the upper end 40u of the wall 40w of the drain pan 40. Anything should do. In short, in the indoor unit 4 according to the present embodiment, it is not necessary that the entire subcooling region Sc of the heat exchanger unit 42 is formed at a position lower than the upper end 40u of the wall 40w of the drain pan 40.

  According to the study of the present inventors, it has been found that near the upper end 40u of the wall portion 40w of the drain pan 40, as shown in FIG. 13, the wind speed is locally increased. Therefore, even if the supercooling region Sc is not formed at all positions lower than the upper end 40u of the wall portion 40w of the drain pan 40, if the supercooling region Sc is formed at least in the vicinity of the upper end 40u, the supercooling of the refrigerant is performed. The degree can be increased.

  Furthermore, in the indoor unit 4 according to the present embodiment, when the indoor heat exchanger 42 is used as a condenser, at least a part of the subcooling region Sc is disposed at a position across the upper end 40u of the wall 40w of the drain pan 40. It may be done. With such an arrangement, the rate at which the liquid refrigerant and the air exchange heat is increased at a position straddling the upper end 40u of the wall portion 40w of the drain pan 40, so that the degree of supercooling of the refrigerant in the supercooling region Sc can be increased. it can.

(4-4) Modification 1D
In the heat exchanger unit 42 according to the present embodiment, the upper and lower sides are defined by the first heat exchanger 52 and the second heat exchanger 62, respectively, but the heat exchanger unit 42 according to the present embodiment as a whole The upper and lower sides may be defined. Specifically, when the heat exchanger unit 42 is connected to the first heat exchanger 52 and the second heat exchanger 62 by a connecting pipe and integrated, the connection port with the gas-side connecting pipe 6a is provided. The side is defined as “upper side”, and the side of the connection port with the liquid side connection pipe 5a is defined as “lower side”. In this case, the heat exchanger unit 42 is formed such that the area of the upper heat exchange area is larger than the area of the lower heat exchange area. In short, in the indoor heat exchanger according to the present embodiment, in the single first heat exchanger 52 or the second heat exchanger 62, the area of the upper heat exchange area (500U or 600U) is the lower heat exchange area ( Even if the area is not larger than (500L or 600L), the area including the upper heat exchange area is larger than the area of the lower heat exchange area as a whole. For example, in the indoor heat exchanger according to the present embodiment, as shown in FIG. 20, the first heat exchanger 52 and the second heat exchanger 62 are connected by connecting pipes 427 and 428 and are integrated. Including what is being done. In the example of FIG. 20, the supercooling regions Sc1 and Sc2 are formed only in the first heat exchanger 52. However, as a whole of the heat exchanger unit 42, the area of the upper heat exchanger It is larger than the area of the exchange area.

  In addition, in the form of the modification 1D, when the heat exchanger unit 42 is used as a condenser, the first heat exchanger 52 on the leeward side of the second heat exchanger 62 on the leeward side has a supercooling region Sc. Is preferably formed.

Second Embodiment
Hereinafter, the same portions as those already described are denoted by the same reference numerals, and duplicate description will be omitted. In addition, in this embodiment, a suffix S may be added to distinguish it 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 in the present embodiment employs a configuration called a duct type.

  FIG. 21 is a schematic sectional view of a duct-type indoor unit 4S according to the present embodiment. In such a duct-type indoor unit 4S, the casing 31S has the outlet 36S on the side. In the duct-type indoor unit 4S, a heat exchanger chamber 31H communicating with the outlet 36S and a blower chamber 31S communicating with the heat exchanger chamber 31H via the partition plate B are formed inside the casing 31S. You. And the indoor heat exchanger 42 is installed in the heat exchanger room 31H. Further, an indoor fan 41 is installed in the blower room 31S. Here, the configuration of the indoor heat exchanger 42 is the same as in the first embodiment.

  Even in the indoor unit 4S having such a configuration, when at least a part of the subcooling region Sc of the indoor heat exchanger 42S is disposed at a position lower than the upper end 40Su of the wall 40Sw of the drain pan 40S, The heat exchange efficiency can be improved as compared with a configuration in which all the subcooling regions Sc are arranged at a position higher than the upper end 40Su of the wall portion 40Sw of the drain pan 40S.

  Note that, in the present embodiment, the configuration in which the plurality of flat multi-hole tubes are “vertically arranged” in the indoor heat exchanger 42S is such that the upper surface and / or the lower surface of each flat multi-hole tube is vertically arranged along the horizontal direction. Instead, as shown in FIG. 21, the upper surface and / or the lower surface of the flat multi-hole tube are vertically arranged in a direction inclined from the horizontal direction. With a heat exchanger or the like having such a configuration, another type of heat exchanger can be mounted as it is, and the heat exchanger or the like can be easily manufactured.

  However, the configuration of the heat exchanger 42S according to the present embodiment is not limited to this, and a plurality of flat multi-hole tubes may be vertically arranged in a direction inclined from the vertical direction as shown in FIG. With a heat exchanger or the like having such a configuration, an airflow having a high flow rate can be passed through the heat exchange region, and the heat exchange efficiency between the refrigerant and the air can be improved.

  Note that the indoor heat exchanger 42S described above may be a heat exchanger unit composed of a plurality of heat exchangers or a single heat exchanger. This 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 mounted, the heat exchange efficiency can be improved as compared with a single unit. Further, when the direction D1 of the refrigerant flow flowing inside the first heat exchanger 52S and the direction D2 of the refrigerant flow flowing inside the second heat exchanger 62S are opposed to each other, uneven temperature in the blown air is suppressed. be able to.

  When the heat exchanger unit 42 has a plurality of heat exchangers, it is preferable that a supercooling region is formed in the heat exchanger on the windward side rather than the heat exchanger on the leeward side. Further, it is preferable that the subcooling region of the leeward heat exchanger is disposed at a position lower than the upper end 40u of the wall 40w of the drain pan 40 than the subcooling region of the leeward heat exchanger.

<Other embodiments>
The embodiments of the present invention and the modifications thereof have been described with reference to the drawings. However, the specific configuration is not limited to these embodiments and the modifications thereof, and may be changed without departing from the gist of the invention. It is possible. For example, in the above-described embodiment and its modifications, the example in which the present invention is applied to the ceiling-mounted and duct-type air conditioners has been described. However, the present invention is not limited to this, and the entire device is disposed below the ceiling. The present invention may be applied to an air conditioner called a suspended ceiling type.

4 indoor units (air conditioning indoor units)
4S indoor unit (air conditioning indoor unit)
Reference Signs List 31 casing 31S casing 31H heat exchanger room 31W air blower chamber 36 outlet 36S outlet 40 drain pan 40S drain pan 40t drain pan bottom 40w drain pan wall 40u drain pan wall upper end 41 indoor fan (fan)
41S Indoor fan (fan)
42 Indoor heat exchanger, heat exchanger unit (heat exchanger)
42S indoor heat exchanger, heat exchanger unit (heat exchanger)
52 1st heat exchanger (heat exchanger)
62 Second heat exchanger (heat exchanger)
500U Upper first heat exchange area (upper heat exchange area)
500L Lower first heat exchange area (Lower heat exchange area)
600U Upper second heat exchange area (upper heat exchange area)
600L Lower second heat exchange area (Lower heat exchange area)
B Partition plate Sc Supercooling area Sc1 Supercooling area Sc2 Supercooling area

JP 2011-099609 A

Claims (8)

A casing (31, 31S) installed indoors;
Fans (41, 41S) provided in the casing;
A heat exchanger (42, 42S, 52, 62) having a plurality of flat multi-hole tubes arranged in the casing and arranged vertically.
A drain pan (40, 40S) provided below the heat exchanger;
An air-conditioning indoor unit (4, 4S) comprising:
The heat exchanger is
It is divided into an upper heat exchange area (500U, 600U) and a lower heat exchange area (500L, 600L),
When used as a condenser, a subcooling region (Sc, Sc1, Sc2) composed of one or more flat multi-hole tubes for supercooling a refrigerant flowing inside is formed in the lower heat exchange region,
The drain pan has a bottom (40t) provided below the heat exchanger, and a wall (40w) provided upright from the bottom and provided on the leeward side of the heat exchanger,
At least a part of the subcooling region is arranged at a position lower than an upper end (40u) of a wall of the drain pan,
Air conditioning indoor unit. The area of the upper heat exchange area is larger than the area of the lower heat exchange area,
The air-conditioning indoor unit according to claim 1. At least a part of the supercooling region is arranged near an upper end of a wall of the drain pan,
The air-conditioning indoor unit according to claim 1. At least a part of the supercooling region is disposed at a position straddling an upper end of a wall of the drain pan.
The air-conditioning indoor unit according to any one of claims 1 to 3. Said casing has an outlet (36) below,
The fan is a centrifugal fan,
The heat exchanger is arranged in the casing to surround the centrifugal fan,
The air-conditioning indoor unit according to any one of claims 1 to 4. The casing has an outlet (36S) on the side,
Inside the casing, a heat exchanger chamber (31H) communicating with the air outlet and a blower chamber (31W) communicating with the heat exchanger chamber via a partition plate (B) are formed.
The heat exchanger is installed in the heat exchanger room,
The fan is installed in the blower room,
The air-conditioning indoor unit according to any one of claims 1 to 4. The heat exchanger is a heat exchanger unit composed of a plurality of heat exchangers,
The air-conditioning indoor unit according to any one of claims 1 to 6. Of the heat exchanger unit, at least a part of the subcooling region of the heat exchanger disposed most leeward with respect to the fan is disposed at a position lower than the upper end of the wall of the drain pan.
The air-conditioning indoor unit according to claim 7.

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