TECHNICAL FIELD
[0001] The present invention relates to an indoor heat exchanger, more particularly, to
an indoor heat exchanger used for exchanging heat between indoor air and refrigerant.
BACKGROUND ART
[0002] As a heat exchanger used for exchanging heat with indoor air in an indoor unit of
an air conditioner, there is known a cross-finned heat exchanger such as that described
in Patent Literature 1 (
WO 2008/041656). In this type of cross-finned heat exchanger, a dead water region is likely to occur
on a leeward side of cylindrical heat transfer tubes that penetrate fins. Because
there is less contribution to heat exchange at this fin portion corresponding to the
dead water region, heat transfer tubes must be provided in at least three rows in
order to secure necessary heat exchange capacity and increase performance. However,
providing three or more rows causes the heat exchanger to increase in size. In addition,
because the air that flows between these heat transfer tubes travels through a path
made narrow by the heat transfer tubes, the heat transfer tubes cause air flow resistance
to increase.
[0003] As an improvement over this type of cross-fmned heat exchanger, there is, for example,
described in Patent Literature 2 (
WO 2013/160957) a heat exchanger that uses flat tubes in place of the tubular heat transfer tubes.
In such a heat exchanger that uses flat pipes, air flow resistance is reduced.
[0004] A further example can be seen in document
EP 2 995 886 A1 showing a heat exchanger configured such that flat tubes in at least two levels bent
or connected to each other at one end in an axial direction of the flat tubes and
the flat tubes in at least two columns connected to each other are included in refrigerant
passages through which refrigerant flows, and a flow direction of gas is counter to
flow of refrigerant through the refrigerant passages in a column direction while the
heat exchanger serves as a condenser.
SUMMARY OF THE INVENTION
<Technical Problem>
[0006] However, a heat exchanger must increase in size through, for example, providing more
rows of tubes in order for the heat exchanger to achieve better performance. Providing
a plurality of rows of flat tubes in the heat exchanger described above causes a problem
in that fins deform when the flat tubes are bent, and this increases air flow resistance.
In addition, flat tubes are longer than cylindrical tubes in the direction in which
indoor air flows, and hence it becomes difficult to discharge condensed water that
is generated in the indoor heat exchanger.
[0007] It is an object of the present invention to provide an indoor heat exchanger that
reduces an increase in air flow resistance and enables easy discharge of condensed
water.
<Solution to Problem>
[0008] An indoor heat exchanger according to the present invention is defined in claim 1.
The dependent claims relate to preferred embodiments of the invention. According to
a first aspect of the present invention includes a first heat exchange portion including
a plurality of first flat tubes arranged in rows and a plurality of first heat transfer
fins that intersect with the plurality of first flat tubes, the first heat transfer
portion being configured to exchange heat between indoor air that flows in a width
direction of the plurality of first flat tubes and refrigerant that flows through
the plurality of first flat tubes; and a second heat exchange portion including a
plurality of second flat tubes arranged in rows and a plurality of second heat transfer
fins that intersect with the plurality of second flat tubes, the second heat transfer
portion being configured to exchange heat between indoor air that flows in a width
direction of the plurality of second flat tubes and refrigerant that flows through
the plurality of second flat tubes, the plurality of first heat transfer fins and
the plurality of second heat transfer fins each including a windward main portion
formed with a notch that receives the first flat tube and the second flat tube respectively,
and a leeward communication portion located on a side opposite to an open end of the
notch, and, in the first heat exchange portion and the second heat exchange portion,
the plurality of first flat tubes and the plurality of second flat tubes in the rows
being arranged in a width direction, and the first heat exchange portion and the second
heat exchange portion each having a bent shape with an inner peripheral side on a
windward side and an outer peripheral side on a leeward side.
[0009] According to the indoor heat exchanger according to the first aspect of the present
invention, because the notches of the first heat transfer fins and the second heat
transfer fins are disposed inward and the first flat tubes and the second flat tubes
each have an inwardly bent shape, deformation of the main portions of the first heat
transfer fins and the main portions of the second heat transfer fins is reduced. Because
the communication portions of the first heat transfer fins and the second heat transfer
fins are disposed on a leeward side, condensed water guided by the indoor air traveling
in the width direction of the first flat tubes and the second flat tubes can be sent
in an up-down direction via the communication portion.
[0010] An indoor heat exchanger according to a second aspect of the present invention is
the indoor heat exchanger according to the first aspect of the present invention,
in which the first heat exchange portion and the second heat exchange portion each
have the bent shape so as to surround an indoor fan with the inner peripheral sides,
and are disposed such that indoor air discharged from the indoor fan disposed on the
inner peripheral side can be guided along the width direction of the plurality of
first flat tubes and the plurality of second flat tubes to pass between the plurality
of first heat transfer fins and between the plurality of second heat transfer fins
and reach the outer peripheral side on which the communication portion of the second
heat transfer fins is located.
[0011] According to the indoor heat exchanger according to the second aspect of the present
invention, the indoor air discharged from the indoor fan surrounded by the inner peripheral
sides of the first heat exchange portion and the second heat exchange portion can
be discharged in the width direction of the first flat tubes and the second flat tubes,
which has low air flow resistance. In addition, condensed water can be sent across
the entire indoor heat exchanger from the inner peripheral sides to the outer peripheral
sides of the first heat exchange portion and the second heat exchange portion.
[0012] The indoor heat exchanger according to a third aspect of the present invention is
the indoor heat exchanger according to the first or second aspect of the present invention,
in which the plurality of first flat tubes are disposed so as to be positioned windward
of windward edges of the plurality of first heat transfer fins by 0 mm or more.
[0013] According to the indoor heat exchanger according to the third aspect of the present
invention, because the plurality of first flat tubes are positioned windward of the
windward edges of the plurality of first heat transfer fins by 0 mm or more, the first
flat tubes protrude leeward of the windward edges of the first heat transfer fins
by 0 mm or more, and hence first abut against a member or other component when, for
example, the first heat exchange portion and the second heat exchange portion are
bent. This reduces the occurrence of buckling of the windward edges of the plurality
of first heat transfer fins, for example.
[0014] The indoor heat exchanger according to a fourth aspect of the present invention is
the indoor heat exchanger according to the third aspect of the present invention,
in which, in the plurality of first flat tubes arranged in rows and the plurality
of second flat tubes arranged in rows, a thickness of tube walls at a windward portion
located windward is larger than a thickness of tube walls at a side portion located
in a row direction of the plurality of first flat tubes and the plurality of second
flat tubes.
[0015] According to the indoor heat exchanger according to the fourth aspect of the present
invention, because the tube walls at the windward portion located windward are thick,
a reduction in compressive strength can be suppressed even if the first flat tubes
and the second flat tubes are damaged by a jig when the first flat tubes and the second
flat tubes are bent using the jig.
[0016] The indoor heat exchanger according to the first aspect of the present invention
is the indoor heat exchanger in which the first heat exchange portion is configured
so as not to make contact with the second heat exchange portion due to a clearance
that is located between leeward edges of the plurality of first heat transfer fins
of the first heat exchange portion and the windward main portions of the plurality
of second heat transfer fins of the second heat exchange portion.
[0017] According to the indoor heat exchanger according to the first aspect of the present
invention, because the first heat exchange portion and the second heat exchange portion,
which have different temperatures, are configured such as not to make contact with
each other, heat transfer can be reduced from one of the first heat exchange portion
and the second heat exchange portion to the other.
[0018] The indoor heat exchanger according to the first aspect of the present invention
is the indoor heat exchanger in which the plurality of second flat tubes are arranged
so as to be positioned windward of windward edges of the plurality of second heat
transfer fins by 0 mm or more.
[0019] According to the indoor heat exchanger according to the first aspect of the present
invention, because the plurality of second flat tubes are positioned windward of the
windward edges of the plurality of second heat transfer fins by 0 mm or more, the
clearance between the first heat exchange portion and the second heat exchange portion
can be easily maintained.
[0020] The indoor heat exchanger according to the first aspect of the present invention
is the indoor heat exchanger in which the plurality of second flat tubes are disposed
so as to be positioned windward of the windward edges of the plurality of second heat
transfer fins by 2 mm or less.
[0021] According to the indoor heat exchanger according to the first aspect of the present
invention, because the plurality of second flat tubes are positioned windward of the
windward edges of the plurality of second heat transfer fins by 2 mm or less, condensed
water is more likely to be drawn by surface tension into a clearance of 2 mm or less
formed between the first heat exchange portion and the second heat exchange portion,
to flow and drop down.
[0022] The indoor heat exchanger according to a fifth aspect of the present invention is
the indoor heat exchanger according to the first of the present invention, in which
the leeward edges of the plurality of first heat transfer fins in the first heat exchange
portion extend in a straight line along the clearance in a vertical direction.
[0023] According to the indoor heat exchanger according to the fifth aspect of the present
invention, because the leeward edges of the plurality of first heat transfer fins
extend in a straight line along the clearance in a vertical direction, condensed water
is more likely to be guided along the leeward edges.
[0024] The indoor heat exchanger according to a sixth aspect of the present invention is
the indoor heat exchanger according to any one of the fifth to fifth aspects of the
present invention, in which the first heat exchange portion and the second heat exchange
portion each have an L-shape, a C-shape, or a rectangular shape when viewed from the
row direction of the plurality of first flat tubes and the plurality of second flat
tubes.
[0025] According to the indoor heat exchanger according to the sixth aspect of the present
invention, because the first heat exchange portion and the second heat exchange portion
each have an L-shape, a C-shape, or a rectangular shape, windward space can be surrounded
by either one or two pairs of the first heat exchange portion and the second heat
exchange portion.
<Advantageous Effects of Invention>
[0026] In the indoor heat exchanger according to the first aspect of the present invention,
an increase in air flow resistance is reduced and the leeward communication portion
improves drainability of water when condensation occurs.
[0027] In the indoor heat exchanger according to the second aspect of the present invention,
drainability of condensed water can be improved by efficiently utilizing air flow
discharged around by the indoor fan.
[0028] In the indoor heat exchanger according to the third aspect of the present invention,
an increase in air flow resistance caused by deformation of the windward edges of
the plurality of first heat transfer fins can be reduced.
[0029] In the indoor heat exchanger according to the fourth aspect of the present invention,
decrease of compressive strength of the first flat tubes and the second flat tubes
at inwardly bent portions is suppressed due to damage from a jig.
[0030] In the indoor heat exchanger according to the fifth aspect of the present invention,
heat exchange capacity is less likely to decrease due to thermal conduction between
the first heat exchange portion and the second heat exchange portion.
[0031] In the indoor heat exchanger according to the sixth aspect of the present invention,
it becomes easy to prevent the degradation of the performance of the first heat exchange
portion and the second heat exchange portion due to thermal conduction between the
first heat exchange portion and the second heat exchange portion.
[0032] In the indoor heat exchanger according to the seventh aspect of the present invention,
drainability of condensed water is improved.
[0033] In the indoor heat exchanger according to the eighth aspect of the present invention,
problems caused by condensed water, such as condensed water splashing outward, can
be reduced.
[0034] In the indoor heat exchanger according to the ninth aspect of the present invention,
the configuration of the device to which the indoor heat exchanger is applied can
be simplified.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035]
FIG. 1 is a perspective view for illustrating the external appearance of an indoor
unit according to an embodiment.
FIG. 2 is a cross-sectional view of the indoor unit in FIG. 1.
FIG. 3 is a schematic plan view of an indoor heat exchanger.
FIG. 4 is a cross-sectional view for illustrating the structure of the indoor heat
exchanger and the vicinity thereof taken along the line I-I in FIG. 3.
FIG. 5 is a schematic view from above illustrating the indoor heat exchanger functioning
as an evaporator.
FIG. 6 is a partially enlarged cross-sectional view of an exemplary relationship between
first and second flat tubes and notches.
FIG. 7 is a schematic view for illustrating an exemplary process of manufacturing
the indoor heat exchanger.
FIG. 8 is a schematic view for illustrating another exemplary process of manufacturing
the indoor heat exchanger.
FIG. 9 is a cross-sectional view for schematically illustrating the relationship between
indoor heat exchanger parts and jigs.
FIG. 10 is a cross-sectional view for explaining wall thicknesses of the first flat
tube and the second flat tube.
FIG. 11 is a partially enlarged cross-sectional view of a first heat exchange portion
and a second heat exchange portion.
FIG. 12 is a schematic view from above for illustrating an indoor heat exchanger according
to a modification example 1A.
FIG. 13 is a schematic view from above for illustrating another indoor heat exchanger
according to the modification example 1A.
FIG. 14 is a diagram for illustrating an internal structure of an indoor unit according
to a modification example 1B when viewed from below.
FIG. 15 is a cross-sectional view of the indoor unit taken along the line II-II in
FIG. 14.
DESCRIPTION OF EMBODIMENTS
(1) Outline of configuration of air conditioner
[0036] FIG. 1 illustrates the external appearance of an indoor unit to which an indoor heat
exchanger according to one embodiment of the present invention is applied. FIG. 2
illustrates the internal structure of the indoor unit in FIG. 1. An indoor unit 100
is a ceiling-mounted indoor unit that is used to heat and cool a room inside, for
example, a building such as a high-rise building through performing a vapor-compression
refrigeration cycle. As illustrated in FIG. 2, the indoor unit 100 is installed into
a ceiling CE of a room inside a building such as a high-rise building. The indoor
unit 100 includes an indoor fan 120 and an indoor heat exchanger 10. In the indoor
unit 100, the indoor fan 120 operates to suck in indoor air through an intake port
101 provided on a lower center part of the indoor unit 100 and discharge this air
from four discharge ports 102 provided in the indoor unit 100. The four discharge
ports 102 of the indoor unit 100 extend parallel to the four sides of a decorative
plate 103 having a substantially square-shaped lower surface, respectively.
[0037] Inside the indoor unit 100, a bell mouth 104 is mounted directly above the intake
port 101. The indoor air sucked in through the intake port 101 is guided to the indoor
fan 120 using this bell mouth 104. The indoor air is discharged from the indoor fan
120 in a direction substantially parallel to the ceiling CE. Then, the indoor air
passes through the indoor heat exchanger 10 that surrounds the indoor fan 120 in a
horizontal direction to be discharged from the indoor fan 120 and then discharged
from the four discharge ports 102 located further outside than the indoor heat exchanger
10.
[0038] Condensation may occur in the indoor heat exchanger 10 when, for example, the temperature
of the indoor heat exchanger 10 becomes lower than the temperature of the room during
a cooling operation. In the indoor unit 100, a drain pan 130 is provided beneath the
indoor heat exchanger 10 to receive condensed water generated by condensation in the
indoor heat exchanger 10. The condensed water generated in the indoor heat exchanger
10 is pulled by gravity so as to flow down through the indoor heat exchanger 10 and
drop from the indoor heat exchanger 10 into the drain pan 130.
(2) Indoor heat exchanger 10
[0039] FIG. 3 illustrates a state in which the indoor heat exchanger 10 is viewed from above.
As illustrated in FIG. 3, the indoor heat exchanger 10 surrounds the indoor fan 120.
The arrows Ar1, Ar2, Ar3 and Ar4 in FIG. 3 indicate the direction of air flow. The
four discharge ports 102 are formed in the directions in which these arrows Ar1 to
Ar4 face, respectively. When viewed from above, the indoor heat exchanger 10 has a
shape similar to the four sides of a square with a diagonal center at the center of
the indoor fan 120. However, a portion corresponding to where a drain pump 140 is
located is recessed toward the inner periphery of the indoor heat exchanger 10.
[0040] The indoor heat exchanger 10 is, for example, a device that partly forms a refrigerant
circuit (not illustrated) which performs a refrigerant cycle and exchanges heat between
refrigerant that flows through the refrigerant circuit and indoor air. A liquid pipe
51 and a gas pipe 52 that extend outward from the indoor heat exchanger 10 are connected
to the refrigerant circuit. Liquid refrigerant and gas refrigerant primarily flow
through the liquid pipe 51 and the gas pipe 52 that extend outward from the indoor
heat exchanger 10, respectively.
(2-1) First heat exchange portion 11 and second heat exchange portion 12
[0041] FIG. 4 illustrates in an enlarged manner a partial cross-sectional structure of the
indoor unit 100 at a place corresponding to a portion taken along the line I-I in
FIG. 3. As illustrated in FIG. 4, the indoor heat exchanger 10 includes a first heat
exchange portion 11 on an inner peripheral side and a second heat exchange portion
12 on an outer peripheral side. In other words, the first heat exchange portion 11
is disposed on a windward side and the second heat exchange portion 12 is disposed
on a leeward side. The first heat exchange portion 11 includes a plurality of first
flat tubes 21 arranged in rows and a plurality of first heat transfer fins 31 that
intersect with the plurality of first flat tubes 21. The first flat tubes 21 and the
first heat transfer fins 31 are substantially orthogonal to one another. Only one
first heat transfer fin 31 is illustrated in FIG. 4. Other first heat transfer fins
31 that are adjacent to the first heat transfer fin 31 illustrated in FIG. 4 are arranged
parallel to the first heat transfer fin 31 in FIG. 4. However, at bent portions 10R
of the indoor heat exchanger 10, these adjacent first heat transfer fins 31 are not
parallel to one another, and an interval between outer peripheral sides of the adjacent
first heat transfer fins 31 is larger than an interval between inner peripheral sides
of the adjacent first heat transfer fins 31. A plurality of flow paths 21a are formed
as one windward-to-leeward row inside one first flat tube 21, and refrigerant flows
through each of these flow paths 21a.
[0042] The second heat exchange portion 12 includes a plurality of second flat tubes 22
arranged in rows and a plurality of second heat transfer fins 32 that intersect with
the plurality of second flat tubes 22. The second flat tubes 22 and the second heat
transfer fins 32 are substantially orthogonal to one another. Only one second heat
transfer fin 32 is illustrated in FIG. 4. Other second heat transfer fins 32 that
are adjacent to the second heat transfer fin 32 illustrated in FIG. 4 are arranged
parallel to the second heat transfer fin 32 in FIG. 4. However, at the bent portions
10R of the indoor heat exchanger 10, these adjacent second heat transfer fins 32 are
not parallel to one another, and an interval between outer peripheral sides of the
adjacent second heat transfer fins 32 is larger than an interval between inner peripheral
sides of the adjacent second heat transfer fins 32. A plurality of flow paths 22a
are formed as one windward-to-leeward row inside one second flat tube 22, and the
refrigerant flows through each of these flow paths 22a.
[0043] FIG. 5 schematically illustrates an exemplary direction of flow of the refrigerant
that flows through the indoor heat exchanger 10. The indoor heat exchanger 10 includes
a flow divider 53 connected to the liquid pipe 51, a liquid header 54 connected to
the flow divider 53, a gas header 55 connected to the gas pipe 52, and a return header
56. The indoor heat exchanger 10 illustrated in FIGS. 3 and 5 includes two pairs of
the first heat exchange portion 11 and the second heat exchange portion 12. The pair
of heat exchange portions disposed near the drain pump 140 is referred to as a "first
pair P1 of the first heat exchange portion 11 and the second heat exchange portion
12" or the "first pair P1" and the other pair of heat exchange portions is referred
to as a "second pair P2 of the first heat exchange portion 11 and the second heat
exchange portion 12" or the "second pair P2."
[0044] In FIG. 5, the flow of refrigerant when the indoor heat exchanger 10 functions as
an evaporator is indicated by the arrows Ar5 to Ar8. In the first pair PI, liquid
refrigerant flows in the direction of the arrow Ar5 after traveling from the liquid
pipe 51 to the first flat tube 21 via the flow divider 53 and the liquid header 54.
Then, the refrigerant that flows through the first flat tube 21 of the first pair
P1 is returned by the return header 56 and flows from the first flat tube 21 into
the second flat tube 22. The refrigerant then travels in the direction of the arrow
Ar6 to the gas pipe 52 via the gas header 55. In the second pair P2, liquid refrigerant
flows in the direction of the arrow Ar7 after traveling from the liquid pipe 51 to
the first flat tube 21 via the flow divider 53 and the liquid header 54. Then, the
refrigerant that flows through the first flat tube 21 of the second pair P2 is returned
by the return header 56 and flows from the first flat tube 21 into the second flat
tube 22. The refrigerant then flows in the direction of the arrow Ar8 to the gas pipe
52 via the gas header 55. In the indoor heat exchanger 10 illustrated in FIG. 5, liquid
refrigerant changes to gas refrigerant by evaporating while flowing through the first
flat tube 21 and the second flat tube 22. The indoor heat exchanger 10 illustrated
in FIG. 5 is formed of a combination of the L-shaped first pair P1 of the first heat
exchange portion 11 and the second heat exchange portion 12 and the L-shaped second
pair P2 of the first heat exchange portion 11 and the second heat exchange portion
12. Note that the first pair P1 has two bent portions 10R and the second pair P2 only
has one bent portion 10R. The shapes of all of these bent portions 10R are classified
as an L-shape.
[0045] As described above, the first pair P1 and the second pair P2 each have an L-shape
such that inner peripheral sides of the first heat exchange portion 11 and the second
heat exchange portion 12 surround the indoor fan 120. Both the first pair P1 and the
second pair P2 are disposed such that indoor air discharged from the indoor fan 120,
which is disposed on the inner peripheral side, can be guided along a width direction
of the first flat tubes 21 and the second flat tubes 22 to pass between a plurality
of the first heat transfer fins 31 and a plurality of the second heat transfer fins
32 and reach an outer peripheral side on which a communication portion 34 (see FIG.
6) of the second heat transfer fin 32 is located.
(2-2) Detailed configuration of first heat transfer fin 31
[0046] FIG. 6 illustrates in a further enlarged manner a part of the first heat transfer
fin 31 and the first flat tube 21 that is fitted into the first heat transfer fin
31 in the first heat exchange portion 11 illustrated in FIG. 4. The second heat exchange
portion 12 has the same structure as that of the first heat exchange portion 11 illustrated
in the enlarged manner in FIG. 6. Therefore, herein, the first heat exchange portion
11 is described, but a description of components of the second heat exchange portion
12 that are the same as those of the first heat exchange portion 11 is omitted.
[0047] The first heat transfer fin 31 includes a windward main portion 33 formed with a
notch 35 that receives the first flat tube 21, and the leeward communication portion
34 located on a side opposite to an open end 35a of the notch 35. The first flat tube
21 is inserted in the direction of the arrow Ar9 in FIG. 6. Similarly, the second
heat transfer fin 32 includes the windward main portion 33 formed with the notch 35
that receives the second flat tube 22, and the leeward communication portion 34 located
on a side opposite to the open end 35a of the notch 35. A water guide rib 36 that
facilitates condensed water discharge is formed in the communication portion 34. This
guide rib 36 is a portion that extends from a pressed groove. A protruded structure
extends in the up-down direction along the guide rib 36 when the guide rib 36 is viewed
from one main surface f1 of the first heat transfer fin 31 (or the second heat transfer
fin 32), while a recessed structure extends in the up-down direction along the guide
rib 36 when the guide rib 36 is viewed from the other main surface on a side opposite
to the one main surface fl. A plurality of raised-lance portions 37 are formed on
the one main surface fl side of the first heat transfer fin 31 (or the second heat
transfer fin 32). Each of the raised-lance portions 37 protrudes in a bridge shape.
As seen in FIG. 6, the raised-lance portions 37 are not formed around the notches
35.
(3) Bending parts of the indoor heat exchanger 10
(3-1) Summary of bending
[0048] A method of forming the bent portions 10R of the indoor heat exchanger 10 illustrated
in FIG. 3 is described with reference to FIGS. 7 to 9. Two jigs are used to form the
bent portions 10R. Examples of such jigs are illustrated in FIGS. 7 and 8. In other
words, the bent portions 10R of the indoor heat exchanger 10 is formed using a rolling
jig 210 and a pressing jig 220. As illustrated in FIG. 7, the rolling jig 210 is brought
into contact with a position at which the bent portion 10R is to be formed, and fixed
to a part 300 of the indoor heat exchanger 10 on a side of an end 301 of the part
300. Then, the pressing jig 220 is pressed against the part 300 from a side opposite
to a rolling part 211 of the rolling jig 210. The pressing jig 220 is pressed against
the part 300 at a position that is closer to the other end 302 of the part 300 than
the position of the rolling part 211.
[0049] Next, as illustrated in FIG. 8, the pressing jig 220 applies force to the part 300
of the indoor heat exchanger 10 to bend the first flat tube 21 and the second flat
tube 22 of the part 300. The curvature radius of the second flat tube 22 is larger
than that of the first flat tube 21 at the position where the bent portion 10R is
formed. Thus, as illustrated in FIG. 7, an end of the second flat tube 22 is designed
to protrude further outward than an end of the first flat tube 21 before the part
300 is bent so that the ends of the first flat tube 21 and the second flat tube 22
are not arranged too far apart from each other at the other end 302 of the part 300
when bending is completed.
[0050] FIG. 9 illustrates a portion of the part 300 in an enlarged manner. In FIG. 9, the
rolling jig 210 and the pressing jig 220 are pushed against the part 300. As is evident
from FIG. 9, it is mainly the first flat tube 21 that makes contact with the rolling
jig 210. Although not illustrated in FIG. 9, upon completion of this step, a plate
is interposed between the first heat exchange portion 11 and the second heat exchange
portion 12 during bending. In other words, force is transmitted from the second flat
tube 22 to the first heat transfer fin 31 via the plate during bending. Similarly,
the area in which the pressing jig 220 comes into contact with the second heat transfer
fin 32 is large. Pressure applied to the second heat transfer fin 32 by the pressing
jig 220 and pressure applied to the first heat transfer fin 31 by the plate are both
smaller than pressure applied to the first flat tube 21 by the rolling jig 210. As
a result, buckling of a leeward edge 31b of the first heat transfer fin 31 and a leeward
edge 32b of the second heat transfer fin 32 (see FIG. 11) is less likely to occur
during the bending.
(3-2) Positional relationship between flat tube and heat transfer fin
[0051] As illustrated in FIG. 6, the plurality of first flat tubes 21 are disposed so as
to be positioned windward of windward edges 31a of the plurality of first heat transfer
fins 31 by 0 mm or more. In other words, a distance D1 illustrated in FIG. 6 between
a windward end portion of the first flat tube 21 and the windward edge 31a of the
first heat transfer fin 31 is 0 mm or more, and is preferably set to 0.5 mm or more
in consideration of, for example, manufacturing errors. As described above, the first
flat tube 21 preferably protrudes outward in order to reduce the amount of force applied
to the first heat transfer fin 31 during the bending.
[0052] In addition, during bending, force is applied to the first flat tube 21 by the rolling
jig 210 and to the second flat tube 22 by the plate interposed between the first flat
tube 21 and the second flat tube 22. The wall thicknesses of the first flat tube 21
and the second flat tube 22 are set in consideration of the force. More specifically,
as illustrated in FIG. 10, a thickness t3 of tube walls 21d, 22d at windward portions
located on the windward side of the first flat tube 21 and the second flat tube 22
is larger than a thickness t2 of the tube walls 21c, 22c at side portions located
in the row direction of the first flat tubes 21 and the second flat tubes 22. The
thickness t3 of the tube walls 21d, 22d at the windward portion located on the windward
side is larger than a thickness t1 of inner walls 21b, 22b that divide flow paths
of the multi-hole first flat tubes 21 and second flat tubes 22.
[0053] FIG. 11 illustrates in an enlarged manner a part of the first heat exchange portion
11 and the second heat exchange portion 12. The first heat exchange portion 11 is
configured such as not to make contact with the second heat exchange portion 12 through
a clearance CL that is located between the leeward edge 31b of the first heat transfer
fin 31 and the windward main portion 33 of the second heat transfer fin 32 of the
second heat exchange portion 12. More specifically, the leeward edges 31b of the plurality
of first heat transfer fins 31 of the first heat exchange portion 11 extend in a straight
line along the clearance CL in a vertical direction. A distance of 2 mm or less is
preferably allocated for the distance D3 between the leeward edge 31b of the first
heat transfer fin 31 and the windward edge 32a of the second heat transfer fin 32.
[0054] As illustrated in FIG. 6, the plurality of second flat tubes 22 are disposed so as
to be positioned windward of the windward edges 32a of the plurality of second heat
transfer fins 32 by 0 mm or more. In other words, the distance D2 illustrated in FIG.
6 between a windward end portion of the second flat tube 22 and the windward edge
32a of the second heat transfer fin 32 is 0 mm or more, and is set to 2 mm or less
such that condensed water is more easily drawn by surface tension to flow and drop
downward. This distance of 2 mm is set in consideration of the size of water droplets.
If this distance is set 2 mm or more, water droplets are not as easily drawn down
by surface tension (capillary action). In addition, in order to reduce the force applied
to the second heat transfer fin 32 during bending, the second flat tube 22 preferably
protrudes outward (the second flat tube 22 preferably protrudes outward by more than
0 mm from the windward edge 32a of the second heat transfer fin 32 and is positioned
windward).
(4) Modification example
(4-1) Modification example 1A
[0055] In the above-described embodiment, the indoor heat exchanger 10 is described by taking
an example in which the indoor heat exchanger 10 is configured to enclose the entire
periphery of windward space in which the indoor fan 120 is disposed when viewed from
the row direction of the first flat tubes 21 and the second flat tubes 22 through
the combination of the L-shaped first pair P1 and the L-shaped second pair. However,
the shape of the indoor heat exchanger 10 for surrounding the windward space in which
the indoor fan 120 is disposed may be, for example, rectangular when viewed from the
row direction of the first flat tubes 21 and the second flat tubes 22, such as that
illustrated in FIG. 12 or 13.
[0056] In FIG. 12, the arrows Ar11, Ar12 indicate the flow of refrigerant when a rectangular
indoor heat exchanger 10 functions as an evaporator. Liquid refrigerant flows in the
direction of the arrow Ar11 after traveling from the liquid pipe 51 to the first flat
tube 21 via the flow divider 53 and the liquid header 54. Then, the refrigerant that
flows through the first flat tube 21 is returned by the return header 56 and flows
from the first flat tube 21 into the second flat tube 22. The refrigerant then travels
in the direction of the arrow Ar12 to the gas pipe 52 via the gas header 55.
[0057] In FIG. 13, the arrows Ar12, Ar14 indicate the flow of refrigerant in the first flat
tube 21 of the first heat exchange portion 11 and the arrows Ar13, Ar15 indicate the
flow of refrigerant in the second flat tube 22 of the second heat exchange portion
12 when the rectangular indoor heat exchanger 10 functions as an evaporator. Liquid
refrigerant flows in the directions of the arrows Ar12, Ar13 after traveling from
the liquid pipe 51 to the first flat tube 21 via the flow divider 53 and the liquid
header 54. Then, the refrigerant that flows through the first flat tube 21 flows in
the direction of the arrows Ar14, Ar15 to the gas pipe 52 via the gas header 55.
(4-2) Modification example IB
[0058] In the above-described embodiment, the indoor heat exchanger 10 is described as surrounds
the entire periphery of the indoor fan 120, but the indoor heat exchanger 10 may have
a configuration that does not surround part of the periphery of the indoor fan. For
example, the indoor heat exchanger 10 may have a C-shape such as that illustrated
in FIGS. 14 and 15 when viewed from the row direction of the first flat tubes 21 and
the second flat tubes 22.
[0059] FIG. 14 illustrates the internal structure of the indoor unit 100 when viewed from
below, and FIG. 15 illustrates a cross-sectional structure of the indoor unit 100
taken along the line II-II in FIG. 14. The indoor unit 100 includes the indoor fan
120 and the indoor heat exchanger 10. In FIG. 14, the C-shaped indoor heat exchanger
10 is the hatched portion. In the indoor unit 100, the indoor fan 120 operates to
suck in indoor air through the intake port 101 provided on a lower center part of
the indoor unit 100 and discharge this air from the discharge port 102 of the indoor
unit 100.
[0060] The bell mouth 104 is mounted directly above the intake port 101 in the indoor unit
100. The indoor air sucked in through the intake port 101 is guided to the indoor
fan 120 using this bell mouth 104. The indoor air is then discharged from the indoor
fan 120 in a substantially horizontal direction. The indoor air passes through the
C-shaped indoor heat exchanger 10 that surrounds the indoor fan 120 in a horizontal
direction to be discharged from the indoor fan 120 and then discharged from the discharge
port 102.
[0061] Condensation may occur in the indoor heat exchanger 10 when, for example, the temperature
of the indoor heat exchanger 10 becomes lower than the temperature of the room during
a cooling operation. In the indoor unit 100, the drain pan 130 is provided beneath
the indoor heat exchanger 10 to receive condensed water generated in the indoor heat
exchanger 10. The condensed water generated in the indoor heat exchanger 10 is pulled
by gravity so as to flow down through the indoor heat exchanger 10 and drop from the
indoor heat exchanger 10 into the drain pan 130.
(4-3) Modification example 1C
[0062] The refrigerant that flows through the first flat tube 21 and the second flat tube
22 according to the above-described embodiment may be a substance other than refrigerant
for vapor compression refrigerant, for example, water.
(4-4) Modification example ID
[0063] In the indoor heat exchanger 10 according to this embodiment, two rows of heat exchange
portions, that is, the first heat exchange portion 11 and the second heat exchange
portion 12 are provided, but the present invention can also be applied to an indoor
heat exchanger having three or more rows of heat exchange portions.
(4-5) Modification example 1E
[0064] The indoor heat exchanger according to the present invention is not limited to being
applied to the ceiling-mounted indoor unit 100 and can also be applied to, for example,
an indoor unit that hangs from a ceiling.
(4-6) Modification example IF
[0065] In the above-described embodiment, the first flat tubes 21 and the second flat tubes
22 are arranged at the same height, but the first flat tubes and the second flat tubes
in the indoor heat exchanger according to the present invention may be arranged in
a staggered fashion.
(5) Characteristics
(5-1)
[0066] As described above, the notches 35 in the first heat transfer fin 31 and the second
heat transfer fin 32 are disposed inward and the first flat tube 21 and the second
flat tube 22 each have an inwardly bent shape. This configuration reduces deformation
of the main portions 33 of the first heat transfer fin 31 and the second heat transfer
fin 32. As a result, because deformation of the main portions 33 of the first heat
transfer fin 31 and the second heat transfer fin 32 is reduced, there is less possibility
of increasing air flow resistance caused by such deformation and an increase in air
flow resistance is thereby reduced.
[0067] In addition, because the communication portions 34 of the first heat transfer fin
31 and the second heat transfer fin 32 are disposed on a leeward side, condensed water
guided by the indoor air traveling in the width direction of the first flat tubes
21 and the second flat tubes 22 can be sent in the up-down direction via the communication
portions 34, particularly guide ribs 36. In this way, drainability when condensation
occurs is improved due to the leeward communication portions 34 of the first flat
tube 21 and the second flat tube 22.
(5-2)
[0068] In the above-described embodiment, as illustrated in FIG. 5, the first pair P1 and
the second pair P2 of the indoor heat exchanger 10 each have an L-shape so as to surround
the indoor fan 120 with the inner peripheral sides thereof. In the modification example
1A, the indoor heat exchanger 10 illustrated in FIGS. 12 and 13 is rectangular so
as to surround the indoor fan 120 with the inner peripheral side thereof. Further,
in modification example 1B, the indoor heat exchanger 10 illustrated in FIG. 14 has
a C-shape so as to surround the indoor fan 120 with the inner peripheral side thereof.
With these configurations, indoor air discharged from the indoor fan 120 arranged
on the inner peripheral side is guided along the width direction of the first flat
tubes 21 and the second flat tubes 22 to pass between a plurality of the first heat
transfer fins 31 and a plurality of the second heat transfer fins 32 and reach the
outer peripheral side on which the communication portion 34 of the second heat transfer
fin 32 is located. As a result, in the indoor heat exchanger 10, drainability of condensed
water is improved by efficiently utilizing air flow discharged around by the indoor
fan 120.
(5-3)
[0069] As described with reference to FIG. 6, the first flat tubes 21 are positioned windward
of the windward edges 31a of the plurality of first heat transfer fins 31 by 0 mm
or more. With this configuration, the first flat tubes 21 protrude leeward of the
windward edges 31a of the first heat transfer fins 31 by 0 mm or more, and hence first
abut against a member such as the rolling jig 210 when, for example, the first heat
exchange portion 11 and the second heat exchange portion 12 are bent. This reduces
the possibility of buckling of the windward edges 31a of the plurality of first heat
transfer fins 31, for example. As a result, an increase in air flow resistance caused
by deformation of the windward edges 31a of the plurality of first heat transfer fins
31 can be reduced.
(5-4)
[0070] When a thickness tt3 of the tube wall 21d, 22d at the windward portion located windward
is larger than the thickness t2 of the tube wall 21c, 22c at the side surface portion
as illustrated in FIG. 10, a reduction in compressive strength can be suppressed even
if the first flat tube 21 and the second flat tube 22 are damaged by the rolling jig
210 when the first flat tube 21 and the second flat tube 22 are bent by the rolling
jig 210. As a result, the compressive strength of the first flat tubes 21 and the
second flat tubes 22 at bent portions toward the inner peripheral side of the indoor
heat exchanger 10 is less likely to decrease.
(5-5)
[0071] By adopting a configuration such as that illustrated in FIG. 11 in which the first
heat exchange portion 11 and the second heat exchange portion 12, which have different
temperatures, are configured not to make contact with each other through the clearance
CL that is located between the leeward edge 31b of the first heat transfer fin 31
and the windward main portion 33 of the second heat transfer fin 32, heat transfer
can be reduced from one of the first heat exchange portion 11 and the second heat
exchange portion 12 to the other. As a result, heat exchange capacity of the first
heat exchange portion 11 and the second heat exchange portion 12 is less likely to
decrease due to thermal conduction between the first heat exchange portion 11 and
the second heat exchange portion 12.
(5-6)
[0072] As illustrated in FIG. 11, because the second flat tubes 22 are positioned windward
of the windward edges 32a of the plurality of second heat transfer fins 32 by 0 mm
or more, the clearance CL can be easily left between the first heat exchange portion
11 and the second heat exchange portion 12. When the clearance CL is left by arranging
the second flat tubes 22 in this way, heat exchange capacity is less likely to decrease
due to thermal conduction between the first heat exchange portion 11 and the second
heat exchange portion 12.
(5-7)
[0073] As illustrated in FIG. 11, because the second flat tubes 22 are positioned windward
of the windward edges of the plurality of second heat transfer fins by 2 mm or less,
a clearance CL of 2 mm or less can be reliably formed between the first heat exchange
portion 11 and the second heat exchange portion 12. In other words, the distance D3
between the leeward edge 31b of the first heat transfer fin 31 and the windward edge
32a of the second heat transfer fin 32 is 2 mm or less. Condensed water is more likely
to be drawn by surface tension into this clearance of 2 mm or less formed between
the first heat exchange portion 11 and the second heat exchange portion 12, to flow
and drop down. As a result, condensed water in the indoor heat exchanger 10 is drained
with better performance.
(5-8)
[0074] As illustrated in FIG. 11, because the leeward edges 31b of the plurality of first
heat transfer fins 31 extend in a straight line along the clearance CL in a vertical
direction, condensed water is more likely to be guided along these leeward edges 31b.
As a result, problems caused by condensed water, such as condensed water splashing
outward, can be reduced.
(5-9)
[0075] The windward space can be surrounded by two L-shaped pairs of the first heat exchange
portion 11 and the second heat exchange portion 12, namely, the first pair P1 and
the second pair P2 as illustrated in FIG. 5, one rectangular pair of the first heat
exchange portion 11 and the second heat exchange portion 12 as illustrated in FIGS.
12 and 13, or one C-shaped pair of the first heat exchange portion and the second
heat exchange portion as illustrated in FIG. 14. As a result, the configuration of
the indoor unit 100 to which the indoor heat exchanger 10 is applied can be simplified.
REFERENCE SIGNS LIST
[0076]
10 Indoor heat exchanger
11 First heat exchange portion
12 Second heat exchange portion
21 First flat tube
21b, 21c, 21d Tube wall
22 Second flat tube
22b, 22c, 22d Tube wall
31 First heat transfer fin
31a Windward edge
31b Leeward edge
32 Second heat transfer fin
32a Windward edge
32b Leeward edge
33 Main portion
34 Communication portion
35 Notch
CITATION LIST
PATENT LITERATURE
1. Innenraum-Wärmetauscher, umfassend:
einen ersten Wärmeaustauschabschnitt (11), der eine Vielzahl von ersten flachen Rohren
(21) beinhaltet, die in Reihen angeordnet sind, und eine Vielzahl von ersten Wärmeübertragungsrippen
(31), die die Vielzahl von ersten flachen Rohren schneiden, wobei der erste Wärmeaustauschabschnitt
konfiguriert ist, Wärme zwischen Innenraumluft, die in einer Breitenrichtung der Vielzahl
von ersten flachen Rohren strömt, und Kältemittel, das durch die Vielzahl von ersten
flachen Rohren strömt, auszutauschen; und
einen zweiten Wärmeaustauschabschnitt (12), der eine Vielzahl von zweiten flachen
Rohren (22) beinhaltet, die in Reihen angeordnet sind, und eine Vielzahl von zweiten
Wärmeübertragungsrippen (32), die die Vielzahl von zweiten flachen Rohren schneiden,
wobei der zweite Wärmeaustauschabschnitt konfiguriert ist, Wärme zwischen Innenraumluft,
die in einer Breitenrichtung der Vielzahl von zweiten flachen Rohren strömt, und Kältemittel,
das durch die Vielzahl von zweiten flachen Rohren strömt, auszutauschen,
sowohl die Vielzahl von ersten Wärmeübertragungsrippen als auch die Vielzahl von zweiten
Wärmeübertragungsrippen einen windzugewandten Hauptabschnitt (33) beinhaltet, der
mit einer Aussparung (35) gebildet ist, die das erste flache Rohr beziehungsweise
das zweite flache Rohr aufnimmt, und einen windabgewandten Verbindungsabschnitt (34),
der an einer Seite gegenüber einem offenen Ende der Aussparung liegt,
im ersten Wärmeaustauschabschnitt und dem zweiten Wärmeaustauschabschnitt die Vielzahl
von ersten flachen Rohren und die Vielzahl von zweiten flachen Rohren in den Reihen
in der Breitenrichtung angeordnet ist und sowohl der erste Wärmeaustauschabschnitt
als auch der zweite Wärmeaustauschabschnitt eine gebogene Form mit einer Innenumfangsseite
an einer windzugewandten Seite und einer Außenumfangsseite an einer windabgewandten
Seite aufweisen;
wobei der erste Wärmeaustauschabschnitt so konfiguriert ist, keinen Kontakt mit dem
zweiten Wärmeaustauschabschnitt aufgrund eines Abstands herzustellen, der zwischen
windabgewandten Kanten (31b) der Vielzahl von ersten Wärmeübertragungsrippen des ersten
Wärmeaustauschabschnitts und den windzugewandten Hauptabschnitten der Vielzahl von
zweiten Wärmeübertragungsrippen des zweiten Wärmeaustauschabschnitts liegt;
wobei die Vielzahl von zweiten flachen Rohren so angeordnet ist, windzugewandt von
windzugewandten Kanten (32a) der Vielzahl von zweiten Wärmeübertragungsrippen um 0
mm oder mehr positioniert zu sein;
wobei die Vielzahl von zweiten flachen Rohren so aufgestellt sind, windzugewandt von
den windzugewandten Kanten der Vielzahl von zweiten Wärmeübertragungsrippen um 2 mm
oder weniger positioniert zu sein.
2. Innenraum-Wärmetauscher nach Anspruch 1, wobei sowohl der erste Wärmeaustauschabschnitt
als auch der zweite Wärmeaustauschabschnitt die gebogene Form aufweisen, um ein Innenraum-Gebläse
(120) mit den Innenumfangsseiten zu umgeben, und so aufgestellt sind, dass Innenraumluft,
die vom an der Innenumfangsseite aufgestellten Innenraum-Gebläse ausgestoßen ist,
entlang der Breitenrichtung der Vielzahl von ersten flachen Rohren und der Vielzahl
von zweiten flachen Rohren geleitet werden kann, um zwischen der Vielzahl von ersten
Wärmeübertragungsrippen und zwischen der Vielzahl von zweiten Wärmeübertragungsrippen
durchzugehen und die Außenumfangsseite zu erreichen, an der der Verbindungsabschnitt
der zweiten Wärmeübertragungsrippe liegt.
3. Innenraum-Wärmetauscher nach Anspruch 1 oder 2, wobei die Vielzahl von ersten flachen
Rohren so aufgestellt ist, windzugewandt von windzugewandten Kanten (31a) der Vielzahl
von ersten Wärmeübertragungsrippen um 0 mm oder mehr positioniert zu sein.
4. Innenraum-Wärmetauscher nach Anspruch 3, wobei in der Vielzahl von ersten flachen
Rohren, die in Reihen angeordnet sind, und der Vielzahl von zweiten flachen Rohren,
die in Reihen angeordnet sind, eine Dicke von Rohrwänden (21d, 22d) bei einem windzugewandten
Abschnitt, der windzugewandt liegt, größer ist als eine Dicke von Rohrwänden (21c,
22c) bei einem Seitenabschnitt, der in einer Reihenrichtung der Vielzahl von ersten
flachen Rohren und der Vielzahl von zweiten flachen Rohren liegt.
5. Innenraum-Wärmetauscher nach Anspruch 1, wobei
die windabgewandten Kanten der Vielzahl von ersten Wärmeübertragungsrippen im ersten
Wärmeaustauschabschnitt sich in einer geraden Linie entlang des Abstands in einer
vertikalen Richtung erstrecken.
6. Innenraum-Wärmetauscher nach einem der Ansprüche 1 bis 5, wobei
sowohl der erste Wärmeaustauschabschnitt als auch der zweite Wärmeaustauschabschnitt
eine L-Form, eine C-Form oder eine rechteckige Form aufweisen, wenn von der Reihenrichtung
der Vielzahl von ersten flachen Rohren und der Vielzahl von zweiten flachen Rohren
betrachtet.