Technical Field
[0001] The present invention relates to a stacking-type header, a heat exchanger, and an
air-conditioning apparatus.
Background Art
[0002] There is a conventional stacking-type header including a first plate-shaped unit
having a plurality of outlet flow passages and a plurality of inlet flow passages,
and a second plate-shaped unit stacked on the first plate-shaped unit and having an
inlet flow passage communicating with the plural outlet flow passages provided in
the first plate-shaped unit and an outlet flow passage communicating with the plural
inlet flow passages provided in the first plate-shaped unit (see, for example, Patent
Literature 1).
Citation List
Patent Literature
Summary of Invention
Technical Problem
[0004] In such a stacking-type header, for example, when gaseous refrigerant flows into
the plural inlet flow passages in the first plate-shaped unit, the pressure loss of
the refrigerant caused between the plural inlet flow passages in the first plate-shaped
unit and the outlet flow passage in the second plate-shaped unit increases. When the
refrigerant with the increased pressure loss flows from the outlet flow passage in
the second plate-shaped unit into a compressor, the suction pressure of the compressor
decreases, and the workload of the compressor increases. That is, the conventional
stacking-type header has the problem in that the pressure loss of the refrigerant
is high.
[0005] The present invention has been made in the context of the above-described problem,
and an object of the invention is to obtain a stacking-type header in which the pressure
loss of refrigerant is reduced. Another object of the invention is to obtain a heat
exchanger including the stacking-type header. A further object of the invention is
to obtain an air-conditioning apparatus including the heat exchanger.
Solution to Problem
[0006] A stacking-type header according to the present invention includes A stacking-type
header comprising: a first plate-shaped unit having a plurality of first outlet flow
passages and a plurality of first inlet flow passages; and a second plate-shaped unit
stacked on the first plate-shaped unit and having at least a part of a distribution
flow passage configured to distribute refrigerant, which passes through a second inlet
flow passage to flow into the second plate-shaped unit, to the plurality of first
outlet flow passages, the second plate-shaped unit having at least a part of a joining
flow passage, the joining flow passage causing refrigerant entering from each of the
first inlet flow passages to join and enter a second outlet passage, wherein a passage
area of one first inlet flow passage of the plurality of first inlet flow passages
is larger than a passage area of one first outlet flow passage of the plurality of
first outlet flow passages communicating with the one first inlet flow passage.
Advantageous Effects of Invention
[0007] In the stacking-type header according to the present invention, the passage area
of one first inlet flow passage of the plurality of first inlet flow passages is larger
than the passage area of one first outlet flow passage of the plurality of first outlet
flow passages communicating with the one first inlet flow passage. Hence, even during
use in a situation where gaseous refrigerant flows into the plurality of first inlet
flow passages in the first plate-shaped unit, it is possible to suppress the increase
in pressure loss of the refrigerant caused between the plurality of first inlet flow
passages in the first plate-shaped unit and the second outlet flow passage in the
second plate-shaped unit.
Brief Description of Drawings
[0008]
[Fig. 1] Fig. 1 illustrates the structure of a heat exchanger according to Embodiment
1.
[Fig. 2] Fig. 2 is an exploded perspective view of a stacking-type header in the heat
exchanger according to Embodiment 1.
[Fig. 3] Fig. 3 is a developed view of the stacking-type header in the heat exchanger
according to Embodiment 1.
[Fig. 4] Fig. 4 illustrates the configuration of an air-conditioning apparatus to
which the heat exchanger of Embodiment 1 is applied.
[Fig. 5] Fig. 5 is an exploded perspective view of a stacking-type header in Modification
-1 of the heat exchanger of Embodiment 1.
[Fig. 6] Fig. 6 is an exploded perspective view of a stacking-type header in Modification-2
of the heat exchanger of Embodiment 1.
[Fig. 7] Fig. 7 is an exploded perspective view of a stacking-type header in Modification-3
of the heat exchanger of Embodiment 1.
[Fig. 8] Fig. 8 includes an exploded perspective view and a cross-sectional view of
the principal part of a stacking-type header in Modification-4 of the heat exchanger
of Embodiment 1.
[Fig. 9] Fig. 9 is an exploded perspective view of a stacking-type header in Modification-5
of the heat exchanger of Embodiment 1.
[Fig. 10] Fig. 10 is an exploded perspective view of a stacking-type header in Modification-6
of the heat exchanger of Embodiment 1.
[Fig. 11] Fig. 11 illustrates the structure of a heat exchanger according to Embodiment
2.
[Fig. 12] Fig. 12 is an exploded perspective view of a stacking-type header in the
heat exchanger according to Embodiment 2.
[Fig. 13] Fig. 13 is a developed view of the stacking-type header in the heat exchanger
according to Embodiment 2.
[Fig. 14] Fig. 14 illustrates the configuration of an air-conditioning apparatus to
which the heat exchanger of Embodiment 2 is applied. Description of Embodiments
[0009] A stacking-type header according to the present invention will be described below
with reference to the drawings.
[0010] While a case in which the stacking-type header of the present invention distributes
refrigerant that flows into a heat exchanger will be described below, the stacking-type
header of the present invention may distribute refrigerant that flows into other devices.
The following structures, actions, and so on are just exemplary, and structures, actions,
and so on are not limited thereto. In the drawings, the same or similar components
are denoted by the same reference numerals, or are not denoted by any reference numeral.
Illustrations of detailed structures are appropriately simplified or omitted. Overlapping
or similar descriptions are appropriately simplified or omitted.
[0011] In the present invention, when one passage is provided, the term "passage area" means
the cross-sectional area of the passage, and when a plurality of passages are provided,
the term "passage area" means the sum of cross-sectional areas of the plural passages.
Embodiment 1
[0012] A heat exchanger according to Embodiment 1 will be described.
[Structure of Heat Exchanger]
[0013] The structure of a heat exchanger according to Embodiment 1 will be described below.
[0014] Fig. 1 illustrates the structure of the heat exchanger according to Embodiment 1.
[0015] As illustrated in Fig. 1, a heat exchanger 1 includes a stacking-type header 2, a
plurality of first heat transfer tubes 3, a holding member 4, and a plurality of fins
5.
[0016] The stacking-type header 2 includes a refrigerant inflow part 2A, a plurality of
refrigerant outflow parts 2B, a plurality of refrigerant inflow parts 2C, and a refrigerant
outflow part 2D. Refrigerant pipes are connected to the refrigerant inflow part 2A
of the stacking-type header 2 and the refrigerant outflow part 2D of the stacking-type
header 2. The first heat transfer tubes 3 are flat tubes subjected to hairpin bending.
The plural first heat transfer tubes 3 are connected between the plural refrigerant
outflow parts 2B of the stacking-type header 2 and the plural refrigerant inflow parts
2C of the stacking-type header 2.
[0017] The first heat transfer tubes 3 are flat tubes each having a plurality of passages.
For example, the first heat transfer tubes 3 are formed of aluminum. The plural first
heat transfer tubes 3 are each connected at two ends to the plural refrigerant outflow
parts 2B and the plural refrigerant inflow parts 2C of the stacking-type header 2
while being held by the holding member 4 shaped like a plate. For example, the holding
member 4 is formed of aluminum. A plurality of fins 5 are joined to the first heat
transfer tubes 3. For example, the fins 5 are formed of aluminum. The first heat transfer
tubes 3 and the fins 5 are preferably joined by brazing. While the number of first
heat transfer tubes 3 is eight in Fig. 1, the present invention is not limited to
such a case.
[Flow of Refrigerant in Heat Exchanger]
[0018] The flow of refrigerant in the heat exchanger according to Embodiment 1 will be described
below.
[0019] Refrigerant flowing through the refrigerant pipe flows into the stacking-type header
2 via the refrigerant inflow part 2A, is distributed, and flows out to the plural
first heat transfer tubes 3 via the plural refrigerant outflow parts 2B. In the plural
first heat transfer tubes 3, the refrigerant exchanges heat with, for example, air
supplied by a fan. After passing through the plural first heat transfer tubes 3, the
refrigerant flows into the stacking-type header 2 via the plural refrigerant inflow
parts 2C, joins together, and flows out to the refrigerant pipe via the refrigerant
outflow part 2D. The refrigerant can flow back.
[0020] [Structure of Laminated Header]
[0021] The structure of the stacking-type header in the heat exchanger of Embodiment 1 will
be described below.
[0022] Fig. 2 is an exploded perspective view of the stacking-type header in the heat exchanger
of Embodiment 1. Fig. 3 is a developed view of the stacking-type header in the heat
exchanger of Embodiment 1. In Fig. 3, illustration of double-sided clad materials
24 is omitted.
[0023] As illustrated in Figs. 2 and 3, the stacking-type header 2 includes a first plate-shaped
unit 11 and a second plate-shaped unit 12. The first plate-shaped unit 11 and the
second plate-shaped unit 12 are stacked.
[0024] The first plate-shaped unit 11 is stacked on the outflow side of the refrigerant.
The first plate-shaped unit 11 includes a first plate-shaped member 21. The first
plate-shaped unit 11 has a plurality of first outlet flow passages 11 A and a plurality
of first inlet flow passages 11 B. The plural first outlet flow passages 11 A correspond
to the plural refrigerant outflow parts 2B in Fig. 1. The plural first inlet flow
passages 11 B correspond to the plural refrigerant inflow parts 2C in Fig. 1.
[0025] The first plate-shaped member 21 has a plurality of passages 21 A and a plurality
of passages 21 B. The plural passages 21 A and the plural passages 21 B are through
holes shaped so that their inner peripheral surfaces follow outer peripheral surfaces
of the first heat transfer tubes 3. The passage area (that is, the cross-sectional
area) of one passage 21 B of the plural passages 21 B is larger than the passage area
(that is, the cross-sectional area) of one passage 21 A of the plural passages 21
A communicating with the one passage 21 B. When the first plate-shaped member 21 is
stacked, the plural passages 21 A function as the plural first outlet flow passages
11 A, and the plural passages 21 B function as the plural first inlet flow passages
11 B. For example, the first plate-shaped member 21 has a thickness of about 1 to
10 mm, and is formed of aluminum. When the plural passages 21 A and 21 B are formed
by, for example, press working, working is simplified, and the production cost is
reduced.
[0026] The second plate-shaped unit 12 is stacked on the inflow side of the refrigerant.
The second plate-shaped unit 12 includes a second plate-shaped member 22 and a plurality
of third plate-shaped members 23_1 to 23_3. The second plate-shaped unit 12 has a
second inlet flow passage 12A, a distribution flow passage 12B, a joining flow passage
12C, and a second outlet flow passage 12D. The distribution flow passage 12B includes
a plurality of branch passages 12b. The joining flow passage 12C includes a mixing
passage 12c. The second inlet flow passage 12A corresponds to the refrigerant inflow
part 2A in Fig. 1. The second outlet flow passage 12D corresponds to the refrigerant
outflow part 2D in Fig. 1.
[0027] A part of the distribution flow passage 12B or a part of the joining flow passage
12C may be provided in the first plate-shaped unit 11. In such a case, it is only
necessary that a passage that allows the inflow refrigerant to return and flow out
should be provided in the first plate-shaped member 21, the second plate-shaped member
22, the plural third plate-shaped members 23_1 to 23_3, and so on. When the passage
that allows the inflow refrigerant to return and flow out is not provided and the
entire distribution flow passage 12B or the entire joining flow passage 12C is provided
in the second plate-shaped unit 12, the width of the stacking-type header 2 can be
made substantially equal to the width of the first heat transfer tubes 3, and this
makes the heat exchanger 1 compact.
[0028] The second plate-shaped member 22 has a passage 22A and a passage 22B. The passage
22A and the passage 22B are circular through holes. The passage area (that is, the
cross-sectional area) of the passage 22B is larger than the passage area (that is,
the cross-sectional area) of the passage 22A. When the second plate-shaped member
22 is stacked, the passage 22A functions as the second inlet flow passage 12A, and
the passage 22B functions as the second outlet flow passage 12D. For example, the
second plate-shaped member 22 has a thickness of about 1 to 10 mm, and is formed of
aluminum. When the passage 22A and the passage 22B are formed by, for example, press
working, working is simplified, and, for example, the production cost is reduced.
[0029] For example, mouthpieces or the like are provided on a surface of the second plate-shaped
member 22 on which other members are not stacked, and the refrigerant pipes are connected
to the second inlet flow passage 12A and the second outlet flow passage 12D via the
mouthpieces or the like. Inner peripheral surfaces of the second inlet flow passage
12A and the second outlet flow passage 12D may be shaped to be fitted on outer peripheral
surfaces of the refrigerant pipes, and the refrigerant pipes may be directly connected
to the second inlet flow passage 12A and the second outlet flow passage 12D without
using mouthpieces or the like. In such a case, for example, the component cost is
reduced.
[0030] The plural third plate-shaped members 23_1 to 23_3 have a plurality of passages 23A_1
to 23A_3. The plural passages 23A_1 to 23A_3 are through grooves each having two end
portions 23a and 23b. When the plural third plate-shaped members 23_1 to 23_3 are
stacked, each of the plural passages 23A_1 to 23A_3 functions as a branch passage
12b. For example, the plural third plate-shaped members 23_1 to 23_3 have a thickness
of about 1 to 10 mm, and are formed of aluminum. For example, when the plural third
plate-shaped members 23A_1 to 23A_3 are formed by press working, working is simplified
and the production cost is reduced.
[0031] The plural third plate-shaped members 23_1 to 23_3 further have a plurality of passages
23B_1 to 23B_3. The plural passages 23B_1 to 23B_3 are rectangular through holes that
penetrate almost the entire areas of the third plate-shaped members 23_1 to 23_3 in
the height direction. The passage area (that is, the cross-sectional area) of the
passages 23B_1 to 23B_3 is larger than the passage area (that is, the sum of cross-sectional
areas) of the plural passages 21 A. When the plural third plate-shaped members 23_1
to 23_3 are stacked, each of the plural passages 23B_1 to 23B_3 functions as a part
of the mixing passage 12c. The plural passages 23B_1 to 23B_3 do not always need to
be rectangular.
[0032] Hereinafter, the plural third plate-shaped members 23_1 to 23_3 are sometimes generically
referred to as third plate-shaped members 23. Hereinafter, the plural passages 23A_1
to 23A_3 are sometimes generically referred to as passages 23A. Hereinafter, the plural
passages 23B_1 to 23B_3 are sometimes generically referred to as passages 23B. Hereinafter,
the holding member 4, the first plate-shaped member 21, the second plate-shaped member
22, and the third plate-shaped members 23 are sometimes generically referred to as
plate-shaped members.
[0033] The passage 23A provided in each third plate-shaped member 23 is shaped to connect
two end portions 23a and 23b via a straight portion 23c perpendicular to the gravitational
direction. Areas of the passage 23A other than an area 23d (hereinafter, referred
to as an opening 23d) in a part between two ends of the straight portion 23c are closed
by a member adjacently stacked on the inflow side of the refrigerant, and areas other
than the end portions 23a and 23b are closed by a member adjacently stacked on the
outflow side of the refrigerant, so that branch passage 12b is formed.
[0034] In order for the inflow refrigerant to branch and flow out to different heights,
the end portion 23a and the end portion 23b are located at different heights. Particularly
when one of the end portion 23a and the end portion 23b is located on the upper side
of the straight portion 23c and the other is located on the lower side of the straight
portion 23c, deviation of the distances from the opening 23d to the end portion 23a
and the end portion 23b along the passage 23A can be reduced without complicating
the shape. Since a straight line that connects the end portion 23a and the end portion
23b is parallel to the longitudinal direction of the third plate-shaped member 23,
the dimension of the third plate-shaped member 23 in the shorter side direction can
be reduced, and this reduces the component cost, weight, and so on. Further, since
the straight line that connects the end portion 23a and the end portion 23b is parallel
to the arrangement direction of the first heat transfer tubes 3, space saving of the
heat exchanger 1 is achieved.
[0035] Each branch passage 12b branches the inflow refrigerant in two and sends out the
refrigerant. For this reason, when eight first heat transfer tubes 3 are connected,
at least three third plate-shaped members 23 are needed. When sixteen first heat transfer
tubes 3 are connected, at least four third plate-shaped members 23 are needed. The
number of first heat transfer tubes 3 to be connected is not limited to the power
of two. In such a case, the branch passage 12b is preferably combined with a passage
that does not branch. The number of first heat transfer tubes 3 to be connected may
be two.
[0036] The stacking-type header 2 is not limited to the one in which the plural first outlet
flow passages 11 A and the plural first inlet flow passages 11 B are arranged along
the gravitational direction. For example, the stacking-type header 2 may be used when
the heat exchanger 1 is disposed in an inclined manner like heat exchangers in a wall-hung
indoor unit of a room air-conditioning apparatus, an outdoor unit of an air-conditioning
apparatus, an outdoor unit of a chiller, and so on. In such a case, the straight portion
23c is preferably a through groove having a shape such as not to be perpendicular
to the longitudinal direction of the third plate-shaped member 23.
[0037] The passage 23A may have other shapes. For example, the passage 23A may have no straight
portion 23c. In such a case, a horizontal portion substantially perpendicular to the
gravitational direction between the end portion 23a and the end portion 23b of the
passage 23A serves as an opening 23d. When the passage 23A has the straight portion
23c, the refrigerant is unlikely to be influenced by gravity when it is branched at
the opening 23d. For example, the passage 23A may be a through groove shaped so that
an area that connects both ends of the straight portion 23c and an area that connects
the end portion 23a and the end portion 23b are branched. When the branch passage
12b branches the inflow refrigerant in two and does not branch the branched refrigerant
into a plurality of parts, uniformity of distribution of the refrigerant can be enhanced.
The areas that connect both ends of the straight portion 23c to the end portion 23a
and the end portion 23b may be straight or curved.
[0038] The plate-shaped members are stacked by brazing. A brazing material for joint may
be supplied by using double-sided clad materials having the brazing material rolled
on both surfaces for all plate-shaped members or for alternate plate-shaped members.
The brazing material for joint may be supplied by using single-sided clad materials
having the brazing material rolled on one surface for all the plate-shaped members.
The brazing material may be supplied by stacking brazing-material sheets between the
plate-shaped members. The brazing material may be supplied by applying brazing material
paste between the plate-shaped members. The brazing material may be supplied by stacking
double-sided clad materials having the brazing material rolled on both surfaces between
the plate-shaped members.
[0039] When the plate-shaped members are stacked by brazing, they are stacked with no gap
therebetween. This suppresses leakage of the refrigerant, and ensures pressure resistance.
When the plate-shaped members are brazed while being pressurized, the occurrence of
brazing failure is suppressed further. When a portion where the refrigerant is apt
to leak is subjected to processing for promoting formation of a fillet, for example,
a rib is formed, the occurrence of brazing failure is suppressed further.
[0040] Further, when all of the members to be brazed, including the first heat transfer
tubes 3 and the fins 5, are formed of the same material (for example, formed of aluminum),
they can be collectively brazed, and this enhances productivity. The first heat transfer
tubes 3 and the fins 5 may be brazed after the stacking-type header 2 is brazed. Alternatively,
only the first plate-shaped unit 11 may be first brazed to the holding member 4, and
the second plate-shaped unit 12 may then be brazed.
[0041] In particular, the brazing material is preferably supplied by stacking plate-shaped
members having the brazing material rolled on both surfaces, that is, double-sided
clad materials between the plate-shaped members. As illustrated in Fig. 2, a plurality
of double-sided clad materials 24_1 to 24_5 are stacked between the plate-shaped members.
Hereinafter, the plural double-sided clad materials 24_1 to 24_5 are sometime generically
referred to as double-sided clad materials 24.
[0042] The double-sided clad materials 24 have passages 24A and passages 24B penetrating
therethrough. When the passages 24A and the passages 24B are formed by press working,
working is simplified, and, for example, the production cost is reduced. When all
of the members to be brazed, including the double-sided clad materials 24, are formed
of the same material (for example, formed of aluminum), they can be collectively brazed,
and this enhances productivity.
[0043] The passages 24A provided in the double-sided clad materials 24 stacked on the second
plate-shaped member 22 and the third plate-shaped members 23 are circular through
holes. The passages 24B provided in the double-sided clad materials 24 stacked on
the third plate-shaped members 23_1 and 23_2 are rectangular through holes that penetrate
almost the entire area of the double-sided clad materials 24 in the height direction.
The passages 24B do not always need to be rectangular. The passage area (that is,
the cross-sectional area) of the passages 24B is larger than the passage area (that
is the sum of cross-sectional areas) of the plural passages 21 A. The plural passages
24B provided in the double-sided clad material 24_4 stacked between the third plate-shaped
ember 23_3 and the first plate-shaped member 21 are rectangular through holes. The
plural passages 24B do not always need to be rectangular. The passage area (that is,
the cross-sectional area) of one passage 24B of the plural passages 24B is larger
than the passage area (that is, the cross-sectional area) of one passage 21 A of the
plural passages 21 A communicating with the one passage 24B.
[0044] The plural passages 24A and the plural passages 24B provided in the double-sided
clad material 24_5 stacked between the first plate-shaped member 21 and the holding
member 4 are through holes shaped so that their inner peripheral surfaces extend along
the outer peripheral surfaces of the first heat transfer tubes 3. The passage area
(that is, the cross-sectional area) of one passage 24B of the plural passages 24B
is larger than the passage area (that is, the cross-sectional area) of one passage
21 A of the plural passages 21 A communicating with the one passage 24B.
[0045] When the double-sided clad materials 24 are stacked, the passages 24A function as
refrigerant separation passages for the first outlet flow passages 11 A, the distribution
flow passage 12B, and the second inlet flow passage 12A, and the passages 24B function
as refrigerant separation passages for the first inlet flow passages 11 B, the joining
flow passage 12C, and the second outlet flow passage 12D. Since the refrigerant separation
passages are formed by the double-sided clad materials 24, separation of the refrigerant
is performed reliably. Further, since separation of the refrigerant is reliably performed,
the flexibility in designing the passages is improved. The double-sided clad materials
24 may be stacked between some of the plate-shaped members, and the brazing material
may be supplied between the other plate-shaped members by other methods.
[0046] End portions of the first heat transfer tubes 3 protrude from the surface of the
holding member 4, the double-sided clad material 24_5 is stacked on the holding member
4, and the inner peripheral surfaces of the passages 24A and 24B of the double-sided
clad material 24_5 are fitted on the outer peripheral surfaces of the end portions.
Hence, the first heat transfer tubes 3 are connected to the first outlet flow passages
11 A and the first inlet flow passages 11 B. The first outlet flow passages 11 A and
the first inlet flow passages 11 B, and the first heat transfer tubes 3 may be positioned,
for example, by fitting projections provided on the holding member 4 in recessed portions
provided in the first plate-shaped unit 11. In such a case, the end portions of the
first heat transfer tubes 3 do not have to protrude from the surface of the holding
member 4. The first heat transfer tubes 3 may be directly connected to the first outlet
flow passages 11 A and the first inlet flow passages 11 B without providing the holding
member 4. In such a case, for example, the component cost is reduced.
[Flow of Refrigerant in Laminated Header]
[0047] A description will be given below of the flow of refrigerant in the stacking-type
header in the heat exchanger of Embodiment 1.
[0048] As illustrated in Figs. 2 and 3, refrigerant that has passed through the passage
22A of the second plate-shaped member 22 flows into the opening 23d of the passage
23A provided in the third plate-shaped member 23_1. The refrigerant that has flowed
in the opening 23d strikes the surface of the adjacently stacked member, and is branched
in two toward both ends of the straight portion 23c. The branched refrigerant reaches
the end portions 23a and 23b of the passage 23A, and flows into the openings 23d of
the passages 23A provided in the third plate-shaped member 23_2.
[0049] Similarly, the refrigerant that has flowed in the opening 23d of each passage 23A
provided in the third plate-shaped member 23_2 strikes the surface of the adjacently
stacked member, and is branched in two toward both ends of the straight portion 23c.
The branched refrigerant reaches the end portions 23a and 23b of the passage 23A,
and flows into the openings 23d of the passages 23A provided in the third plate-shaped
member 23_3.
[0050] Similarly, the refrigerant that has flowed in the opening 23d of each passage 23A
provided in the third plate-shaped member 23_3 strikes the surface of the adjacently
stacked member, and is branched in two toward both ends of the straight portion 23c.
The branched refrigerant reaches the end portions 23a and 23b of the passage 23A,
passes through the passages 21 A of the first plate-shaped member 21, and flows into
the first heat transfer tubes 3.
[0051] The refrigerant, which has flowed out from the passages 21 A of the first plate-shaped
member 21 and has passed through the first heat transfer tubes 3, flows into the passages
21 B of the first plate-shaped member 21. The refrigerant that has flowed in the passages
21 B of the first plate-shaped member 21 flows into the passages 23B provided in the
third plate-shaped members 23 so as to be mixed. The mixed refrigerant passes through
the passage 22B of the second plate-shaped member 22, and flows out to the refrigerant
pipe.
[Use Mode of Heat Exchanger]
[0052] An example of a use mode of the heat exchanger according to Embodiment 1 will be
described below.
[0053] While a case in which the heat exchanger according to Embodiment 1 is used in an
air-conditioning apparatus will be described below, the present invention is not limited
to such a case. For example, the heat exchanger of Embodiment 1 may be used in other
refrigeration cycle apparatuses including a refrigerant circuit. Further, while a
case in which cooling operation and heating operation are switched in the air-conditioning
apparatus, the present invention is not limited to such a case, and only cooling operation
or heating operation may be performed.
[0054] Fig. 4 illustrates the configuration of an air-conditioning apparatus to which the
heat exchanger of Embodiment 1 is applied. In Fig. 4, the flow of refrigerant in cooling
operation is shown by solid arrows, and the flow of the refrigerant in heating operation
is shown by dotted arrows.
[0055] As illustrated in Fig. 4, an air-conditioning apparatus 51 includes a compressor
52, a four-way valve 53, a heat-source-side heat exchanger 54, an expansion device
55, a load-side heat exchanger 56, a heat-source-side fan 57, a load-side fan 58,
and a controller 59. The compressor 52, the four-way valve 53, the heat-source -heat
exchanger 54, the expansion device 55, and the load-side heat exchanger 56 are connected
by refrigerant pipes to form a refrigerant circuit.
[0056] To the controller 59, for example, the compressor 52, the four-way valve 53, the
expansion device 55, the heat-source-side fan 57, the load-side fan 58, and various
sensors are connected. The controller 59 switches the passage of the four-way valve
53 to switch between cooling operation and heating operation. The heat-source-side
heat exchanger 54 functions as a condenser in the cooling operation and functions
as an evaporator in the heating operation. The load-side heat exchanger 56 functions
as an evaporator in the cooling operation and functions as a condenser in the heating
operation.
[0057] The flow of refrigerant during the cooling operation will be described.
[0058] A high-pressure and high-temperature gaseous refrigerant discharged from the compressor
52 flows into the heat-source-side heat exchanger 54 via the four-way valve 53, is
condensed into a high-pressure liquid refrigerant by heat exchange with outdoor air
supplied by the heat-source-side fan 57, and flows out from the heat-source-side heat
exchanger 54. The high-pressure liquid refrigerant that has flowed out from the heat-source-side
heat exchanger 54 flows into the expansion device 55, and is turned into a low-pressure
two-phase gas-liquid refrigerant. The low-pressure two-phase gas-liquid refrigerant
flowing out from the expansion device 55 flows into the load-side heat exchanger 56,
is evaporated into a low-pressure gaseous refrigerant by heat exchange with indoor
air supplied by the load-side fan 58, and flows out from the load-side heat exchanger
56. The low-pressure gaseous refrigerant flowing out from the load-side heat exchanger
56 is sucked by the compressor 52 via the four-way valve 53.
[0059] The flow of the refrigerant during heating operation will be described.
[0060] A high-pressure and high-temperature gaseous refrigerant discharged from the compressor
52 flows into the load-side heat exchanger 56 via the four-way valve 53, is condensed
into a high-pressure liquid refrigerant by heat exchange with indoor air supplied
by the load-side fan 58, and flows out from the load-side heat exchanger 56. The high-pressure
liquid refrigerant that has flowed out from the load-side heat exchanger 56 flows
into the expansion device 55, where it is turned into a low-pressure two-phase gas-liquid
refrigerant. The low-pressure two-phase gas-liquid refrigerant flowing out from the
expansion device 55 flows into the heat-source-side heat exchanger 54, is evaporated
into a low-pressure gaseous refrigerant by heat exchange with outdoor air supplied
by the heat-source-side fan 57, and flows out from the heat-source-side heat exchanger
54. The low-pressure gaseous refrigerant flowing out from the heat-source-side heat
exchanger 54 is sucked by the compressor 52 via the four-way valve 53.
[0061] The heat exchanger 1 is used in at least one of the heat-source-side heat exchanger
54 and the load-side heat exchanger 56. The heat exchanger 1 is connected so that
the refrigerant flows from the distribution flow passage 12B of the stacking-type
header 2 into the first heat transfer tubes 3 and the refrigerant flows from the first
heat transfer tubes 3 into the joining flow passage 12C of the stacking-type header
2 when the heat exchanger 1 operates as an evaporator. That is, when the heat exchanger
1 operates as the evaporator, a two-phase gas-liquid refrigerant flows from the refrigerant
pipe into the distribution flow passage 12B of the stacking-type header 2, and a gaseous
refrigerant flows from the first heat transfer tubes 3 into the joining flow passage
12C of the stacking-type header 2. When the heat exchanger 1 operates as a condenser,
a gaseous refrigerant flows from the refrigerant pipe into the joining flow passage
12C of the stacking-type header 2, and a liquid refrigerant flows from the first heat
transfer tubes 3 into the distribution flow passage 12B of the stacking-type header
2.
[Operation of Heat Exchanger]
[0062] The operation of the heat exchanger according to Embodiment 1 will be described below.
[0063] In the stacking-type header 2, the passage area of one first inlet flow passage 11
B of the plural first inlet flow passages 11 B is larger than the passage area of
one first outlet flow passage 11 A of the plural first outlet flow passages 11 A that
communicates with the first inlet flow passage 11 B. For this reason, even during
use in a situation where the gaseous refrigerant flows into the plural first inlet
flow passages 11 B in the first plate-shaped unit 11, it is possible to suppress the
increase in pressure loss of the refrigerant caused between the plural first inlet
flow passages 11 B of the first plate-shaped unit 11 and the second outlet flow passage
12D of the second plate-shaped unit 12.
[0064] Further, in the stacking-type header 2, the passage area of the joining flow passage
12c is larger than the passage area of the plural first outlet flow passages 11 A.
For this reason, even during use in a situation where the gaseous refrigerant flows
into the plural first inlet flow passages 11 B of the first plate-shaped unit 11,
it is possible to suppress the increase in pressure loss of the refrigerant caused
between the plural first inlet flow passages 11 B of the first plate-shaped unit 11
and the second outlet flow passage 12D of the second plate-shaped unit 12.
[0065] In the stacking-type header, the passage area of the second outlet flow passage 12D
is larger than the passage area of the second inlet flow passage 12A. For this reason,
even during use in a situation where the gaseous refrigerant flows into the plural
first inlet flow passages 11 B of the first plate-shaped unit 11, it is possible to
suppress the increase in pressure loss of the refrigerant caused in the second outlet
flow passage 12D of the second plate-shaped unit 12.
[0066] In particular, even during use in a situation where the refrigerant flowing from
the stacking-type header 2 into the first heat transfer tubes 3 is in a two-phase
gas-liquid state and the refrigerant flowing from the first heat transfer tubes 3
into the stacking-type header 2 is in the gas state, it is possible to suppress the
increase in pressure loss of the refrigerant caused between the plural first inlet
flow passages 11 B of the first plate-shaped unit 11 and the second outlet flow passage
12D of the second plate-shaped unit 12. When the heat exchanger 1 operates as an evaporator
and the gaseous refrigerant flowing out from the stacking-type header 2 is sucked
by the compressor 52, the refrigerant whose increase in pressure loss is suppressed
is sucked by the compressor 52. This suppresses the increase in workload of the compressor
52 due to the decrease in suction pressure of the compressor 52, and, for example,
performance of the air-conditioning apparatus 51 is enhanced.
[0067] In particular, when the heat transfer tubes are changed from circular tubes to flat
tubes, for example, in order to reduce the refrigerant amount and to achieve space
saving of the heat exchanger, the conventional stacking-type header must be increased
in size in the circumferential direction perpendicular to the inflow direction of
the refrigerant. However, the stacking-type header 2 does not have to be increased
in size in the circumferential direction perpendicular to the inflow direction of
the refrigerant, and this leads to space saving of the heat exchanger 1. That is,
when the heat transfer tubes are changed from circular tubes to flat tubes in the
conventional stacking-type header, the passage cross-sectional area in the heat transfer
tubes decreases, and the pressure loss occurring in the heat transfer tubes increases.
Hence, the necessity of increasing the number of paths (that is, the number of heat
transfer tubes) by further decreasing the angular interval of the plural grooves that
form the branch passage occurs, and the stacking-type header is increased in size
in the circumferential direction perpendicular to the inflow direction of the refrigerant.
In contrast, in the stacking-type header 2, even when the necessary of increasing
the number of paths occurs, it is only necessary to increase the number of third plate-shaped
members 23. Hence, the increase in size of the stacking-type header 2 in the circumferential
direction perpendicular to the inflow direction of the refrigerant is suppressed.
The stacking-type header 2 is not limited to the one in which the first heat transfer
tubes 3 are flat tubes.
[Modification-1]
[0068] Fig. 5 is an exploded perspective view of a stacking-type header in Modification-1
of the heat exchanger according to Embodiment 1.
[0069] As illustrated in Fig. 5, in third plate-shaped members 23, peripheral edges of passages
23B may be enlarged to be closer to peripheral edges of passages 23A. When the passages
23B in all the third plate-shaped members 23 have the same shape, the pressure loss
is reduced. For this reason, the passages 23B penetrate areas that do not overlap
with any of the passages 23A. Passages 24B of double-sided clad materials 24 stacked
between a second plate-shaped member 22 and a third plate-shaped member 23_3 also
have the same shape.
[Modification-2]
[0070] Fig. 6 is an exploded perspective view of a stacking-type header in Modification-2
of the heat exchanger according to Embodiment 1.
[0071] As illustrated in Fig. 6, the number of third plate-shaped members 23 may be reduced
by forming a plurality of passages 22A in a second plate-shaped member 22, that is,
by forming a plurality of second inlet flow passages 12A in a second plate-shaped
unit 12. This structure reduces, for example, the component cost and weight. The passage
area (that is, the cross-sectional area) of a passage 22B is larger than the passage
area (that is, the sum of cross-sectional areas) of the plural passages 22A.
[Modification-3]
[0072] Fig. 7 is an exploded perspective view of a stacking-type header in Modification-3
of the heat exchanger according to Embodiment 1.
[0073] As illustrated in Fig. 7, a second plate-shaped member 22 and third plate-shaped
members 23 may have a plurality of passages 22B and a plurality of passages 23B. That
is, a joining flow passage 12C may have a plurality of mixing passages 12c. A plurality
of passages 24B of double-sided clad materials 24 stacked between the second plate-shaped
member 22 and a third plate-shaped member 23_3 have the same shape as that of the
plural passages 23B. The passage area (the sum of cross-sectional areas) of the plural
passages 22B is larger than the passage area (that is, the cross-sectional area) of
a passage 22A. The passage area (that is, the sum of cross-sectional areas) of the
plural passages 23B is larger than the passage area (that is, the sum of cross-sectional
areas) of a plurality of passages 21 A. The passage area (that is, the sum of cross-sectional
areas) of the plural passages 24B is larger than the passage area (that is, the sum
of cross-sectional areas) of the plural passages 21 A.
[Modification-4]
[0074] Fig. 8 includes a perspective view of the principal part and a cross-sectional view
of the principal part in an exploded state of a stacking-type header in Modification-4
of the heat exchanger according to Embodiment 1. Fig. 8(a) is a perspective view of
the principal part of the stacking-type header in the exploded state, and Fig. 8(b)
is a cross-sectional view of a third plate-shaped member 23, taken along line A-A
of Fig. 8(a).
[0075] As illustrated in Fig. 8, any of passages 23A provided in third plate-shaped members
23 is a bottomed groove. In such a case, a circular through hole 23e is provided in
each of an end portion 23a and an end portion 23b of a bottom surface of the groove
of the passage 23A. In this structure, double-sided clad materials 24 do not have
to be stacked between the plate-shaped members so that passages 24A functioning as
refrigerant separation passages are provided between branch passages 12b. This enhances
production efficiency. While the refrigerant outflow side of the passage 23A is the
bottom surface in Fig. 8, the refrigerant inflow side of the passage 23A may be the
bottom surface. In such a case, it is only necessary that a through hole should be
provided in an area corresponding to an opening 23d.
[Modification-5]
[0076] Fig. 9 is an exploded perspective view of a stacking-type header in Modification-5
of the heat exchanger according to Embodiment 1.
[0077] As illustrated in Fig. 9, a passage 22A serving as a second inlet flow passage 12A
may be provided in a stacked member other than a second plate-shaped member 22, that
is, for example, in another plate-shaped member or a double-sided clad material 24.
In such a case, for example, the passage 22A is formed by a through hole that extends
through the plate-shaped member from a side surface to a surface on the side of the
second plate-shaped member 22.
[Modification-6]
[0078] Fig. 10 is an exploded perspective view of a stacking-type header in Modification-6
of the heat exchanger according to Embodiment 1.
[0079] As illustrated in Fig. 10, a passage 22B serving as a second outlet flow passage
12D may be provided in, for example, a plate-shaped member other than a second plate-shaped
member 22 of a second plate-shaped unit 12 or a double-sided clad material 24. In
such a case, for example, it is only necessary that a cutout should be provided to
communicate between a part of a passage 23B or a passage 24B and a side surface of
a third plate-shaped member 23 or a double-sided clad material 24. The passage 22B
serving as the second outlet flow passage 12D may be provided in a first plate-shaped
member 21 by bending back a mixing passage 12c.
Embodiment 2
[0080] A heat exchanger according to Embodiment 2 will be described.
[0081] Descriptions overlapping with or similar to those of Embodiment 1 are appropriately
simplified or omitted.
[Structure of Heat Exchanger]
[0082] The structure of the heat exchanger according to Embodiment 2 will be described below.
[0083] Fig. 11 illustrates the structure of the heat exchanger according to Embodiment 2.
[0084] As illustrated in Fig. 11, a heat exchanger 1 includes a stacking-type header 2,
a plurality of first heat transfer tubes 3, a plurality of second heat transfer tubes
6, a holding member 4, and a plurality of fins 5.
[0085] The stacking-type header 2 includes a plurality of refrigerant return parts 2E.
The second heat transfer tubes 6 are flat tubes subjected to hairpin bending, similarly
to the first heat transfer tubes 3. The plural first heat transfer tubes 3 are connected
between a plurality of refrigerant outflow parts 2B and the plural refrigerant return
parts 2E in the stacking-type header 2, and the plural second heat transfer tubes
6 are connected between the plural refrigerant return parts 2E and a plurality of
refrigerant inflow parts 2C in the stacking-type header 2.
[Flow of Refrigerant in Heat Exchanger]
[0086] A description will be given below of the flow of refrigerant in the heat exchanger
according to Embodiment 2.
[0087] Refrigerant flowing through a refrigerant pipe flows into the stacking-type header
2 via a refrigerant inflow part 2A, is distributed, and flows out to the plural first
heat transfer tubes 3 via the plural refrigerant outflow parts 2B. In the plural first
heat transfer tubes 3, the refrigerant exchanges heat with, for example, air supplied
by a fan. The refrigerant that has passed through the plural first heat transfer tubes
3 flows into the plural refrigerant return parts 2E of the stacking-type header 2,
is returned, and flows out to the plural second heat transfer tubes 6. In the plural
second heat transfer tubes 6, the refrigerant exchanges heat with, for example, air
supplied by a fan. The refrigerant that has passed through the plural second heat
transfer tubes 6 flows into the stacking-type header 2 via the plural refrigerant
inflow parts 2C, joins, and flows out to a refrigerant pipe via a refrigerant outflow
part 2D. The refrigerant can flow back.
[Structure of Laminated Header]
[0088] A description will be given below of the structure of the stacking-type header in
the heat exchanger according to Embodiment 2.
[0089] Fig. 12 is an exploded perspective view of the stacking-type header in the heat exchanger
according to Embodiment 2. Fig. 13 is a developed view of the stacking-type header
in the heat exchanger according to Embodiment 2. In Fig. 13, illustration of double-sided
clad materials 24 is omitted.
[0090] As illustrated in Figs. 12 and 13, the stacking-type header 2 includes a first plate-shaped
unit 11 and a second plate-shaped unit 12. The first plate-shaped unit 11 and the
second plate-shaped unit 12 are stacked.
[0091] The first plate-shaped unit 11 has a plurality of first outlet flow passages 11 A,
a plurality of first inlet flow passages 11 B, and a plurality of return passages
11 C. The plural return passages 11 C correspond to the plural refrigerant return
parts 2E in Fig. 11.
[0092] A first plate-shaped member 21 has a plurality of passages 21 C. The plural passages
21 C are through holes shaped so that inner peripheral surfaces thereof surround outer
peripheral surfaces of refrigerant outflow-side end portions of the first heat transfer
tubes 3 and outer peripheral surfaces of refrigerant inflow-side end portions of the
second heat transfer tubes 6. When the first plate-shaped member 21 is stacked, the
plural passages 21C function as the plural return passages 11C.
[0093] In particular, brazing material is preferably supplied by stacking double-sided clad
materials 24 having the brazing material rolled on both surfaces between the plate-shaped
members. Passages 24C provided in a double-sided clad material 24_5 stacked between
the holding member 4 and the first plate-shaped member 21 are through holes shaped
so that inner peripheral surfaces thereof surround the outer peripheral surfaces of
the refrigerant outflow-side end portions of the first heat transfer tubes 3 and the
outer peripheral surfaces of the refrigerant inflow-side end portions of the second
heat transfer tubes 6. When the double-sided clad materials 24 are stacked, the passages
24C function as refrigerant separation passages of the return passages 11C.
[Flow of Refrigerant in Laminated Header]
[0094] A description will be given below of the flow of refrigerant in the stacking-type
header in the heat exchanger according to Embodiment 2.
[0095] As illustrated in Figs. 12 and 13, the refrigerant that has flowed out from the passages
21 A of the first plate-shaped member 21 and has passed through the first heat transfer
tubes 3 flows into the passages 21C of the first plate-shaped member 21, is returned,
and flows into the second heat transfer tubes 6. The refrigerant that has passed through
the second heat transfer tubes 6 flows into the passages 21 B of the first plate-shaped
member 21. The refrigerant that has flowed in the passages 21 B of the first plate-shaped
member 21 flows into passages 23B provided in third plate-shaped members 23 so as
to be mixed. The mixed refrigerant passes through the passage 22B of the second plate-shaped
member 22, and flows out to the refrigerant pipe.
[Use Mode of Heat Exchanger]
[0096] An example of a use mode of the heat exchanger according to Embodiment 2 will be
described below.
[0097] Fig. 14 illustrates the configuration of an air-conditioning apparatus to which the
heat exchanger of Embodiment 2 is applied.
[0098] As illustrated in Fig. 14, the heat exchanger 1 is used in at least one of a heat-source-side
heat exchanger 54 and a load-side heat exchanger 56. The heat exchanger 1 is connected
so that refrigerant flows from a distribution flow passage 12B of the stacking-type
header 2 into the first heat transfer tubes 3 and the refrigerant flows from the second
heat transfer tubes 6 into a joining flow passage 12C of the stacking-type header
2 when the heat exchanger 1 operates as an evaporator. That is, when the heat exchanger
1 operates as the evaporator, a two-phase gas-liquid refrigerant flows from the refrigerant
pipe into the distribution flow passage 12B of the stacking-type header 2 and a gaseous
refrigerant flows from the second heat transfer tubes 6 into the joining flow passage
12C of the stacking-type header 2. Further, when the robot system 1 operates as a
condenser, a gaseous refrigerant flows from the refrigerant pipe into the joining
flow passage 12C of the stacking-type header 2 and a liquid refrigerant flows from
the first heat transfer tubes 3 into the distribution flow passage 12B of the stacking-type
header 2.
[0099] Further, the heat exchanger 1 is disposed so that the first heat transfer tubes 3
are located on the upstream side (windward side) of the second heat transfer tubes
6 in an airflow produced by a heat-source-side fan 57 or a load-side fan 58. That
is, the flow of the refrigerant from the second heat transfer tubes 6 to the first
heat transfer tubes 3 is opposed to the airflow. The temperature of the refrigerant
in the first heat transfer tubes 3 is lower than the temperature of the refrigerant
in the second heat transfer tubes 6. The temperature of the airflow produced by the
heat-source-side fan 57 or the load-side fan 58 is lower on the upstream side of the
heat exchanger 1 than on the downstream side of the heat exchanger 1. As a result,
in particular, the refrigerant can be subcooled (subjected to so-called SC) by the
low-temperature airflow flowing on the upstream side of the heat exchanger 1, and
this enhances condenser performance. The heat-source-side fan 57 and the load-side
fan 58 may be provided on the windward side or the leeward side.
[Operation of Heat Exchanger]
[0100] The operation of the heat exchanger according to Embodiment 2 will be described below.
[0101] In the heat exchanger 1, the plural return passages 11C are provided in the first
plate-shaped unit 11, and the plural second heat transfer tubes 6 are connected in
addition to the plural first heat transfer tubes 3. For example, while the heat exchange
amount can be increased by increasing the area of the heat exchanger 1 when viewed
from the front side, a housing that contains the heat exchanger 1 is increased in
size in this case. Further, while the heat exchange amount can be increased by reducing
the interval of the fins 5 to increase the number of fins 5, it is difficult to set
the interval of the fins 5 less than about 1 mm from the viewpoints of drainage performance,
frosting performance, and dust resistance, and the increase in heat exchange amount
sometimes becomes insufficient. In contrast, when the number of rows of the heat transfer
tubes is increased as in the heat exchanger 1, the heat exchange amount can be increased
without changing, for example, the area of the heat exchanger 1 when viewed from the
front side and the interval of the fins 5. When the number of rows of the heat transfer
tubes becomes two, the heat exchange amount increases by a factor of about 1.5 or
more. The number of rows of the heat transfer tubes may be three or more. Further,
for example, the area of the heat exchanger 1 when viewed from the front side, and
the interval of the fins 5 may be changed.
[0102] The header (stacking-type header 2) is provided on only one side of the heat exchanger
1. For example, when the heat exchanger 1 is disposed while being bent along a plurality
of side surfaces of the housing containing the heat exchanger 1 in order to increase
the mount volume of the heat exchange section, the end portions are not aligned among
the rows of heat transfer tubes owing to the differences in curvature radius of the
bent portions among the rows of heat transfer tubes. When the header (stacking-type
header 2) is provided on only one side of the heat exchanger 1, as in the stacking-type
header 2, even if the end portions are not aligned among the rows of heat transfer
tubes, it is only necessary that the end portions should be aligned on only one side.
This improves the flexibility in design and production efficiency. In particular,
the heat exchanger 1 can be bent after the members of the heat exchanger 1 are joined,
and this further enhances the production efficiency.
[0103] When the heat exchanger 1 operates as the condenser, the first heat transfer tubes
3 are located on the windward side of the second heat transfer tubes 6. When a header
is provided on each side of the heat exchanger, it is difficult to enhance the condenser
performance by making differences in refrigerant temperature among the rows of heat
transfer tubes. Particularly when the first heat transfer tubes 3 and the second heat
transfer tubes 6 are flat tubes, the flexibility in bending is low, unlike circular
tubes. Hence, it is difficult to make the differences in temperature of the refrigerant
among the rows of heat transfer tubes by deforming the passages of the refrigerant.
In contrast, when the first heat transfer tubes 3 and the second heat transfer tubes
6 are connected to the stacking-type header 2 as in the heat exchanger 1, the differences
in temperature of the refrigerant are necessarily made among the rows of heat transfer
tubes. Thus, the opposed relationship between the flow of the refrigerant and the
airflow can be easily achieved without deforming the passages of the refrigerant.
[0104] While Embodiment 1 and Embodiment 2 have been described above, the present invention
is not limited to the descriptions of Embodiments. For example, the entirety or a
part of each Embodiment, Modifications, and so on can be combined.
Reference Signs List
[0105] 1: heat exchanger, 2: stacking-type header, 2A: refrigerant inflow part, 2B: refrigerant
outflow part, 2C: refrigerant inflow part, 2D: refrigerant outflow part, 2E: refrigerant
return part, 3: first heat transfer tube, 4: holding member, 5: fin, 6: second heat
transfer tube, 11: first plate-shaped unit, 11 A: first outlet flow passage, 11 B:
first inlet flow passage, 11C: return passage, 12: second plate-shaped unit, 12A:
second inlet flow passage, 12B: distribution flow passage, 12C: joining flow passage,
12D: second outlet flow passage, 12b: branch passage, 12c: mixing passage, 21: first
plate-shaped member, 21A to 21C: passage, 22: second plate-shaped member, 22A, 22B:
passage, 23, 23_1 to 23_3: third plate-shaped member, 23A, 23B, 23A_1 to 23A_3, 23B_1
to 23B_3: passage, 23a, 23b: end portion, 23c: straight portion, 23d: opening, 23e:
through hole, 24, 24_1 to 24_5: double-sided clad material, 24A to 24C: passage, 51:
air-conditioning apparatus, 52: compressor, 53: four-way valve, 54: heat-source-side
heat exchanger, 55: expansion device, 56: load-side heat exchanger, 57: heat-source-side
fan, 58: load-side fan, 59: controller.