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FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
REFRIGERATION CYCLE APPARATUS;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED
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DESCRIPTION
TECHNICAL FIELD
[0001] The present disclosure relates to a refrigeration cycle apparatus.
5 BACKGROUND ART
[0002] Mixed refrigerants have been taken into consideration as refrigerants each
having a low global warming potential (GWP). Among the mixed refrigerants, a
zeotropic mixed refrigerant has been used in which refrigerants having different boiling
points are mixed. In the case of the zeotropic mixed refrigerant, the temperature of
10 the refrigerant is changed in accordance with a degree of dryness of the refrigerant in a
gas-liquid two-phase region. That is, a temperature gradient is generated. In this
temperature gradient, the temperature of the refrigerant is decreased as the degree of
dryness of the refrigerant is smaller.
[0003] For example, Japanese Patent Laying-Open No. 7-269985 (PTL 1) discloses a
15 heat exchanger of an air conditioner using a zeotropic mixed refrigerant. In this heat
exchanger, flow passages of heat exchange pipes are located in a plurality of rows
arranged on the upstream side and downstream side of air. A refrigerant outlet in the
upstream side row and a refrigerant inlet in the downstream side row are located side
by side in a direction in which air flows.
20 CITATION LIST
PATENT LITERATURE
[0004] PTL 1: Japanese Patent Laying-Open No. 7-269985
SUMMARY OF INVENTION
TECHNICAL PROBLEM
25 [0005] In the heat exchanger of the air conditioner described in the above publication,
at a portion at which the refrigerant outlet in the upstream side row and the refrigerant
inlet in the downstream side row are located side by side, a temperature difference
between the refrigerant and the air is small, thus resulting in a decreased heat exchange
amount.
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[0006] The present disclosure has been made to solve the above-described problem and
has an object to provide a refrigeration cycle apparatus so as to suppress a decrease in
heat exchange amount while using a zeotropic mixed refrigerant having a low global
warming potential.
SOLUTION 5 TO PROBLEM
[0007] A refrigeration cycle apparatus of the present disclosure comprises a refrigerant
circuit and a refrigerant. The refrigerant circuit comprises a compressor, a condenser,
a pressure reducing valve, and an evaporator. The refrigerant circulates through the
refrigerant circuit in order of a compressor, a condenser, a pressure reducing valve, and
10 an evaporator. The refrigerant is a zeotropic mixed refrigerant. At least one of the
condenser and the evaporator comprises a first heat exchange unit located windward
and a second heat exchange unit located leeward in a first direction in which air flows.
Each of the first heat exchange unit and the second heat exchange unit comprises an
inflow passage and an outflow passage for the refrigerant that are located in a plurality
15 of stages arranged in a second direction crossing the first direction. The refrigerant
flows out from the outflow passage of the second heat exchange unit into the inflow
passage of the first heat exchange unit. The outflow passage of the second heat
exchange unit is located in the same stage as the outflow passage of the first heat
exchange unit in the second direction.
20 ADVANTAGEOUS EFFECTS OF INVENTION
[0008] According to the refrigeration cycle apparatus of the present disclosure, the
refrigerant is a zeotropic mixed refrigerant. The outflow passage of the second heat
exchanger is located in the same stage as the outflow passage of the first heat exchange
unit in the second direction. Therefore, a heat exchange amount can be suppressed
25 from being decreased while using the zeotropic mixed refrigerant having a low global
warming potential.
BRIEF DESCRIPTION OF DRAWINGS
[0009] Fig. 1 is a refrigerant circuit diagram showing a refrigeration cycle apparatus
according to a first embodiment.
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Fig. 2 is a perspective view schematically showing a configuration of a heat
exchanger of the refrigeration cycle apparatus according to the first embodiment.
Fig. 3 is a cross sectional view schematically showing the configuration of the
heat exchanger of the refrigeration cycle apparatus according to the first embodiment.
Fig. 4 is a graph showing respective temperatures of refrigerant 5 and air in the
heat exchanger of the refrigeration cycle apparatus according to the first embodiment.
Fig. 5 is a cross sectional view schematically showing a configuration of a heat
exchanger according to a comparative example for the first embodiment.
Fig. 6 is a graph showing respective temperatures of refrigerant and air in the
10 heat exchanger according to the comparative example for the first embodiment.
Fig. 7 is a perspective view schematically showing a configuration of a heat
exchanger of a refrigeration cycle apparatus according to a second embodiment.
Fig. 8 is a cross sectional view schematically showing the configuration of the
heat exchanger of the refrigeration cycle apparatus according to the second
15 embodiment.
Fig. 9 is a cross sectional view schematically showing a configuration of a heat
exchanger according to a comparative example for the second embodiment.
Fig. 10 is a cross sectional view schematically showing a configuration of a heat
exchanger in a modification of the refrigeration cycle apparatus according to the second
20 embodiment.
Fig. 11 is a cross sectional view schematically showing a configuration of a heat
exchanger of a refrigeration cycle apparatus according to a third embodiment.
Fig. 12 is a diagram showing positions of a heat exchanger and a fan of a
refrigeration cycle apparatus according to a fourth embodiment.
25 Fig. 13 is a cross sectional view schematically showing a configuration of a heat
exchanger of a refrigeration cycle apparatus according to a fifth embodiment.
Fig. 14 is a cross sectional view for illustrating thermal loss in a heat exchanger
according to a comparative example for the fifth embodiment.
DESCRIPTION OF EMBODIMENTS
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[0010] Hereinafter, embodiments will be described with reference to figures. It
should be noted that in the description below, the same or corresponding portions are
denoted by the same reference characters, and will not be described repeatedly.
[0011] First Embodiment.
A configuration of a refrigeration cycle apparatus 100 according 5 to a first
embodiment will be described with reference to Fig. 1. Examples of refrigeration
cycle apparatus 100 include an air conditioner, a refrigerator, and the like. In the first
embodiment, the air conditioner will be described as an exemplary refrigeration cycle
apparatus 100. Refrigeration cycle apparatus 100 includes a refrigerant circuit RC, a
10 refrigerant, a controller CD, and blower apparatuses 6, 7.
[0012] Refrigerant circuit RC includes a compressor 1, a four-way valve 2, an outdoor
heat exchanger 3, a pressure reducing valve 4, and an indoor heat exchanger 5.
Compressor 1, four-way valve 2, outdoor heat exchanger 3, pressure reducing valve 4,
and indoor heat exchanger 5 are connected to one another by tubes. Refrigerant
15 circuit RC is configured to circulate the refrigerant. Refrigerant circuit RC is
configured to perform a refrigeration cycle in which the refrigerant circulates with the
phase of the refrigerant being changed.
[0013] Compressor 1, four-way valve 2, outdoor heat exchanger 3, pressure reducing
valve 4, controller CD, and blower apparatus 6 are accommodated in outdoor unit 101.
20 Indoor heat exchanger 5 and blower apparatus 7 are accommodated in indoor unit 102.
[0014] Refrigerant circuit RC is configured to circulate the refrigerant in the order of
compressor 1, four-way valve 2, outdoor heat exchanger (condenser) 3, pressure
reducing valve 4, indoor heat exchanger (evaporator) 5, and four-way valve 2 during a
cooling operation. Further, refrigerant circuit RC is configured to circulate the
25 refrigerant in the order of compressor 1, four-way valve 2, indoor heat exchanger
(condenser) 5, pressure reducing valve 4, outdoor heat exchanger (evaporator) 3, and
four-way valve 2 during a heating operation.
[0015] The refrigerant flows through refrigerant circuit RC in the order of compressor
1, the condenser, pressure reducing valve 4, and the evaporator. The refrigerant is a
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zeotropic mixed refrigerant. That is, among mixed refrigerants, the refrigerant is a
zeotropic mixed refrigerant in which refrigerants having different boiling points are
mixed. The refrigerant is a zeotropic mixed refrigerant having a temperature gradient
in which the temperature of the refrigerant is changed in accordance with a degree of
dryness of the refrigerant in a gas-liquid two-phase region. 5 Specifically, the
refrigerant is a zeotropic mixed refrigerant having a temperature gradient in which the
temperature of the refrigerant is decreased as the degree of dryness of the refrigerant is
smaller. Examples of the refrigerant include R407C, R454A, and the like.
[0016] Controller CD is configured to control each apparatus and the like of
10 refrigeration cycle apparatus 100 by performing calculation, instruction and the like.
Controller CD is electrically connected to compressor 1, four-way valve 2, pressure
reducing valve 4, blower apparatuses 6, 7, and the like, and is configured to control
operations of them.
[0017] Compressor 1 is configured to compress the refrigerant. Compressor 1 is
15 configured to compress and discharge the suctioned refrigerant. Compressor 1 may be
variable in capacity. Compressor 1 may be variable in capacity by adjusting the
rotation speed of compressor 1 based on an instruction from controller CD.
[0018] Four-way valve 2 is configured to switch flow of the refrigerant so as to cause
the refrigerant compressed by compressor 1 to flow to outdoor heat exchanger 3 or
20 indoor heat exchanger 5. Four-way valve 2 is configured to cause the refrigerant
discharged from compressor 1 to flow to outdoor heat exchanger (condenser) 3 during
the cooling operation. Four-way valve 2 is configured to cause the refrigerant
discharged from compressor 1 to flow to indoor heat exchanger (evaporator) 5 during
the heating operation.
25 [0019] Outdoor heat exchanger 3 is configured to exchange heat between the
refrigerant flowing inside outdoor heat exchanger 3 and the air flowing outside outdoor
heat exchanger 3. Outdoor heat exchanger 3 is configured to function as a condenser
to condense the refrigerant during the cooling operation, and function as an evaporator
to evaporate the refrigerant during the heating operation. Outdoor heat exchanger 3 is
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a fin-and-tube type heat exchanger having a plurality of fins and a heat transfer tube
extending through the plurality of fins.
[0020] Pressure reducing valve 4 is configured to expand the refrigerant condensed by
the condenser so as to reduce the pressure of the refrigerant. Pressure reducing valve
4 is configured to reduce the pressure of the refrigerant condensed 5 by outdoor heat
exchanger (condenser) 3 during the cooling operation, and to reduce the pressure of the
refrigerant condensed by indoor heat exchanger (evaporator) 5 during the heating
operation. Pressure reducing valve 4 is, for example, an electromagnetic valve.
[0021] Indoor heat exchanger 5 is configured to exchange heat between the refrigerant
10 flowing inside indoor heat exchanger 5 and the air flowing outside indoor heat
exchanger 5. Indoor heat exchanger 5 is configured to function as an evaporator to
evaporate the refrigerant during the cooling operation, and function as a condenser to
condense the refrigerant during the heating operation. Indoor heat exchanger 5 is a
fin-and-tube type heat exchanger having a plurality of fins and a heat transfer tube
15 extending through the plurality of fins.
[0022] Blower apparatus 6 is configured to blow outdoor air to outdoor heat exchanger
3. That is, blower apparatus 6 is configured to supply air to outdoor heat exchanger 3.
Blower apparatus 6 may be configured to adjust an amount of air flowing around
outdoor heat exchanger 3 by adjusting the rotation speed of blower apparatus 6 based
20 on an instruction from controller CD, thereby adjusting a heat exchange amount
between the refrigerant and the air.
[0023] Blower apparatus 7 is configured to blow indoor air to indoor heat exchanger 5.
That is, blower apparatus 7 is configured to supply air to indoor heat exchanger 5.
Blower apparatus 7 may be configured to adjust an amount of air flowing around
25 indoor heat exchanger 5 by adjusting the rotation speed of blower apparatus 7 based on
an instruction from controller CD, thereby adjusting a heat exchange amount between
the refrigerant and the air.
[0024] Next, an operation of refrigeration cycle apparatus 100 will be described with
reference to Fig. 1. Solid arrows in Fig. 1 indicate flow of the refrigerant during the
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cooling operation, and broken arrows in Fig. 1 indicate flow of the refrigerant during
the heating operation.
[0025] Refrigeration cycle apparatus 100 can selectively perform the cooling operation
and the heating operation. During the cooling operation, the refrigerant circulates in
refrigerant circuit RC in the order of compressor 1, four-way valve 5 2, outdoor heat
exchanger 3, pressure reducing valve 4, indoor heat exchanger 5, and four-way valve 2.
During the cooling operation, outdoor heat exchanger 3 functions as a condenser.
Heat exchange is performed between the refrigerant flowing through outdoor heat
exchanger 3 and the air blown by blower apparatus 6. During the cooling operation,
10 indoor heat exchanger 5 functions as an evaporator. Heat exchange is performed
between the refrigerant flowing through indoor heat exchanger 5 and the air blown by
blower apparatus 7.
[0026] During the heating operation, the refrigerant circulates in refrigerant circuit RC
in the order of compressor 1, four-way valve 2, indoor heat exchanger 5, pressure
15 reducing valve 4, outdoor heat exchanger 3, and four-way valve 2. During the heating
operation, indoor heat exchanger 5 functions as a condenser. Heat exchange is
performed between the refrigerant flowing through indoor heat exchanger 5 and the air
blown by blower apparatus 7. During the heating operation, outdoor heat exchanger 3
functions as an evaporator. Heat exchange is performed between the refrigerant
20 flowing through outdoor heat exchanger 3 and the air blown by blower apparatus 6.
[0027] Next, a configuration of outdoor heat exchanger 3 functioning as a condenser or
an evaporator will be described in detail with reference to Figs. 2 and 3. It should be
noted that indoor heat exchanger 5 functions as a condenser or an evaporator in the
same manner as outdoor heat exchanger 3, and may have the same configuration as that
25 of outdoor heat exchanger 3. In the present embodiment, at least one of outdoor heat
exchanger 3 and indoor heat exchanger 5 functioning as a condenser or an evaporator
may have the following configuration.
[0028] Outdoor heat exchanger 3 has a plurality of fins F and a heat transfer tube P
extending through the plurality of fins F. Heat transfer tube P includes a plurality of
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heat transfer portions P1 and a plurality of connection portions P2. The plurality of
heat transfer portions P1 are portions extending through the plurality of fins F. The
plurality of heat transfer portions P1 are formed in the form of straight lines. The
plurality of connection portions P2 are portions that connect heat transfer portions P1 to
each other outside the plurality of fins F. Each of the plurality of connection 5 portions
P2 is formed to have a U-shape.
[0029] Outdoor heat exchanger 3 has a first heat exchange unit C1 and a second heat
exchange unit C2. First heat exchange unit C1 is located windward in a first direction
D1 in which air flows. First heat exchange unit C1 is located in a first row in first
10 direction D1. Second heat exchange unit C2 is located leeward in first direction D1.
Second heat exchange unit C2 is located in a second row in first direction D1.
[0030] Each of first heat exchange unit C1 and second heat exchange unit C2 has an
inflow passage IF and an outflow passage OF for the refrigerant that are located in a
plurality of stages arranged in a second direction D2 crossing first direction D1.
15 Outflow passage OF of second heat exchange unit C2 is located in the same stage as
outflow passage OF of first heat exchange unit C1 in second direction D2. Outflow
passage OF of second heat exchange unit C2 is located to overlap with outflow passage
OF of first heat exchange unit C1 in first direction D1. In other words, outflow
passage OF of second heat exchange unit C2 is located to overlap with outflow passage
20 OF of first heat exchange unit C1 when viewed in first direction D1. In the present
embodiment, inflow passage IF of second heat exchange unit C2 is located in the same
stage as inflow passage IF of first heat exchange unit C1 in second direction D2.
Inflow passage IF of second heat exchange unit C2 is located to overlap with inflow
passage IF of first heat exchange unit C1 in first direction D1.
25 [0031] First direction D1 may be orthogonal to second direction D2. First direction
D1 may be a horizontal direction. Second direction D2 may be an upward/downward
direction (vertical direction). Third direction D3 is a direction in which heat transfer
portions P1 extend in the form of straight lines. Third direction D3 may be orthogonal
to first direction D1 and second direction D2.
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[0032] In each of first heat exchange unit C1 and second heat exchange unit C2, the
plurality of heat transfer portions P1 are located in the plurality of stages arranged in
second direction D2. In the present embodiment, the plurality of heat transfer portions
P1 are located in four stages. That is, the plurality of heat transfer portions P1 are
located in a first stage S1 to a fourth stage S4. In the present 5 embodiment, inflow
passage IF of each of first heat exchange unit C1 and second heat exchange unit C2 is
heat transfer portion P1 located in first stage S1. Outflow passage OF of each of first
heat exchange unit C1 and second heat exchange unit C2 is heat transfer portion P1
located in fourth stage S4.
10 [0033] In each of first heat exchange unit C1 and second heat exchange unit C2, the
plurality of heat transfer portions P1 are connected by connection portions P2 as
follows. Heat transfer portion P1 of first stage S1 is connected to heat transfer portion
P1 of second stage S2 on the back side by connection portion P2. Heat transfer
portion P1 of second stage S2 is connected to heat transfer portion P1 of third stage S3
15 on the front side by connection portion P2. Heat transfer portion P1 of third stage S3
is connected to heat transfer portion P1 of fourth stage S4 on the back side by
connection portion P2. Heat transfer portion P1 of first stage S1 of first heat exchange
unit C1 is connected to heat transfer portion P1 of fourth stage S4 of second heat
exchange unit C2 on the front side by connection portion P2.
20 [0034] Next, flows of the refrigerant and the air in outdoor heat exchanger 3 will be
described with reference to Figs. 2 and 3.
[0035] The refrigerant flows into second heat exchange unit C2 via inflow passage IF,
which is heat transfer portion P1 of first stage S1 of second heat exchange unit C2.
The refrigerant flows from inflow passage IF, which is heat transfer portion P1 of first
25 stage S1 of second heat exchange unit C2, to outflow passage OF, which is heat
transfer portion P1 of fourth stage S4 of second heat exchange unit C2. Thereafter,
the refrigerant flows from outflow passage OF of second heat exchange unit C2 to
inflow passage IF of first heat exchange unit C1. The refrigerant flows into first heat
exchange unit C1 via inflow passage IF, which is heat transfer portion P1 of first stage
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S1 of first heat exchange unit C1. The refrigerant flows from inflow passage IF,
which is heat transfer portion P1 of first stage S1 of first heat exchange unit C1, to
outflow passage OF, which is heat transfer portion P1 of fourth stage S4 of first heat
exchange unit C1. Thereafter, the refrigerant flows out from first heat exchange unit
C1. The refrigerant flows through first heat exchange unit 5 C1 and second heat
exchange unit C2 in the form of an inversed N-shape.
[0036] The refrigerant flows from second heat exchange unit C2 toward first heat
exchange unit C1. The air flows from first heat exchange unit C1 toward second heat
exchange unit C2. Therefore, the flow of the refrigerant flowing through second heat
10 exchange unit C2 and first heat exchange unit C1 is a counter flow with respect to the
flow of the air flowing through first heat exchange unit C1 and second heat exchange
unit C2.
[0037] Temperatures of the refrigerant and the air in outdoor heat exchanger 3 will be
described with reference to Figs. 3 and 4. Each of solid arrows in Fig. 4 indicates a
15 temperature of the refrigerant, and each of broken arrows in Fig. 4 indicates a
temperature of the air. In Fig. 4, each of two-headed arrows indicate a temperature
difference between the refrigerant and the air.
[0038] Fig. 4 (a) shows the temperatures of the refrigerant and the air at heat transfer
portion P1 of first stage S1 of each of the first heat exchange unit and the second heat
20 exchange unit. Fig. 4 (b) shows the temperatures of the refrigerant and the air at heat
transfer portion P1 of fourth stage S4 of each of the first heat exchange unit and the
second heat exchange unit.
[0039] As shown in Fig. 4 (a), a temperature difference ΔT1 between the refrigerant
and the air at heat transfer portion P1 of first stage S1 of first heat exchange unit C1
25 and a temperature difference ΔT2 between the refrigerant and the air at heat transfer
portion P1 of first stage S1 of second heat exchange unit C2 are secured. As shown in
Fig. 4 (b), a temperature difference ΔT3 between the refrigerant and the air at heat
transfer portion P1 of first stage S1 in first heat exchange unit C1 and a temperature
difference ΔT4 between the refrigerant and the air at heat transfer portion P1 of fourth
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stage S4 in second heat exchange unit C2 are secured. It should be noted that a
temperature Ta of suction air is constant.
[0040] Next, functions and effects of refrigeration cycle apparatus 100 according to the
first embodiment will be described in comparison with a comparative example.
[0041] Referring to Figs. 5 and 6, the flow of the refrigerant flowing 5 through first heat
exchange unit C1 and second heat exchange unit C2 in outdoor heat exchanger 3 of the
comparative example for the first embodiment is different from the flow of the
refrigerant flowing through first heat exchange unit C1 and second heat exchange unit
C2 in outdoor heat exchanger 3 of refrigeration cycle apparatus 100 according to the
10 first embodiment. Fig. 6 (a) shows temperatures of the refrigerant and the air at heat
transfer portion P1 of first stage S1 of each of first heat exchange unit C1 and second
heat exchange unit C2. Fig. 6 (b) shows temperatures of the refrigerant and the air at
heat transfer portion P1 of fourth stage S4 of each of first heat exchange unit C1 and
second heat exchange unit C2.
15 [0042] In outdoor heat exchanger 3 of the comparative example for the first
embodiment, inflow passage IF of second heat exchange unit C2 is heat transfer portion
P1 located in fourth stage S4. Outflow passage OF of second heat exchange unit C2 is
heat transfer portion P1 located in first stage S1. Inflow passage IF of first heat
exchange unit C1 is heat transfer portion P1 located in fourth stage S4. Outflow
20 passage OF of first heat exchange unit C1 is heat transfer portion P1 located in first
stage S1.
[0043] In outdoor heat exchanger 3 of the comparative example for the first
embodiment, the refrigerant flows into second heat exchange unit C2 via inflow
passage IF, which is heat transfer portion P1 of first stage S1 of second heat exchange
25 unit C2. The refrigerant flows from inflow passage IF, which is heat transfer portion
P1 of first stage S1 of second heat exchange unit C2, to outflow passage OF, which is
heat transfer portion P1 of fourth stage S4 of second heat exchange unit C2.
Thereafter, the refrigerant flows into first heat exchange unit C1 via inflow passage IF,
which is heat transfer portion P1 of the fourth stage of first heat exchange unit C1. In
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first heat exchange unit C1, the refrigerant flows from inflow passage IF, which is heat
transfer portion P1 of fourth stage S4, to outflow passage OF, which is heat transfer
portion P1 of first stage S1. The refrigerant flows through first heat exchange unit C1
and second heat exchange unit C2 in the form of a U-shape.
[0044] In outdoor heat exchanger 3 of the comparative example 5 for the first
embodiment, a temperature difference ΔT4 between the refrigerant and the air is small
at heat transfer portion P1 of fourth stage S4 of second heat exchange unit C2. This is
due to the following factor. At heat transfer portion P1 of fourth stage S4 of first heat
exchange unit C1, a temperature difference ΔT3 between the refrigerant and the air is
10 large, so that a heat exchange amount is large. Accordingly, the temperature of the
blown air from first heat exchange unit C1 is increased. Since the temperature of the
blown air from first heat exchange unit C1 is the temperature of the suctioned air in
second heat exchange unit C2, a temperature difference is small between the
temperature of the suctioned air in second heat exchange unit C2 and the refrigerant.
15 As a result, the heat exchange amount is decreased in outflow passage OF, which is
heat transfer portion P1 of fourth stage S4 of second heat exchange unit C2.
[0045] On the other hand, according to refrigeration cycle apparatus 100 of the first
embodiment, referring to Figs. 2 and 3, outflow passage OF of second heat exchange
unit C2 is located in the same stage as outflow passage OF of first heat exchange unit
20 C1 in second direction D2. Therefore, temperature difference ΔT4 between the
refrigerant and the air is small in outflow passage OF of second heat exchange unit C2.
This is due to the following factor. At heat transfer portion P1 of fourth stage S4 of
first heat exchange unit C1, temperature difference ΔT3 between the refrigerant and the
air is small, so that a heat exchange amount is small. Therefore, the temperature of
25 the blown air from first heat exchange unit C1 is suppressed from being increased.
Since the temperature of the blown air from first heat exchange unit C1 is the
temperature of the suctioned air in second heat exchange unit C2, the temperature
difference is large between the temperature of the suctioned air in second heat
exchange unit C2 and the refrigerant. Therefore, temperature difference ΔT between
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the refrigerant and the air is secured. As a result, the heat exchange amount in
outflow passage OF of second heat exchange unit C2 is suppressed from being
decreased. This leads to improved heat exchanger performance in outflow passage
OF of second heat exchange unit C2.
[0046] In refrigeration cycle apparatus 100 according to the first 5 embodiment, the
refrigerant is a zeotropic mixed refrigerant. Therefore, according to refrigeration
cycle apparatus 100 of the first embodiment, the heat exchange amount can be
suppressed from being decreased while using the zeotropic mixed refrigerant having a
low global warming potential.
10 [0047] Second Embodiment.
A refrigeration cycle apparatus 100 according to a second embodiment has the
same configuration, functions, and effects as those of refrigeration cycle apparatus 100
according to the first embodiment unless otherwise stated particularly.
[0048] The configuration of outdoor heat exchanger 3 in refrigeration cycle apparatus
15 100 according to the second embodiment will be described with reference to Figs. 7
and 8.
[0049] In the second embodiment, outdoor heat exchanger 3 has two paths through
which the refrigerant flows. That is, outdoor heat exchanger 3 has a first path PA and
a second path PB. It should be noted that outdoor heat exchanger 3 may have two or
20 more paths.
[0050] Outdoor heat exchanger 3 has a first heat exchange region HF1 and a second
heat exchange region HF2 located in second direction D2. First heat exchange region
HF1 and second heat exchange region HF2 are located adjacent to each other in second
direction D2. First heat exchange region HF1 has a first path PA. Second heat
25 exchange region HF2 has a second path PB. First path PA and second path PB are
configured such that the refrigerant flowing through first path PA and the refrigerant
flowing through second path PB flow in parallel with each other. First path PA and
second path PB are located line-symmetrically with respect to each other in second
direction D2.
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[0051] Each of first heat exchange region HF1 and second heat exchange region HF2
has an inflow passage IF and an outflow passage OF of each of first heat exchange unit
C1 and second heat exchange unit C2. In each of first heat exchange region HF1 and
second heat exchange region HF2, outflow passage OF of second heat exchange unit
C2 is located in the same stage as outflow passage OF of first heat exchange 5 unit C1 in
second direction D2.
[0052] Each of first heat exchange region HF1 and second heat exchange region HF2
has first heat exchange unit C1 and second heat exchange unit C2. In the present
embodiment, in each of first heat exchange region HF1 and second heat exchange
10 region HF2, the plurality of heat transfer portions P1 are located in first stage S1 to
fourth stage S4.
[0053] In the present embodiment, in first heat exchange region HF1, inflow passage
IF of each of first heat exchange unit C1 and second heat exchange unit C2 is heat
transfer portion P1 located in first stage S1. Outflow passage OF of each of first heat
15 exchange unit C1 and second heat exchange unit C2 is heat transfer portion P1 located
in fourth stage S4.
[0054] In the present embodiment, in second heat exchange region HF2, inflow
passage IF of each of first heat exchange unit C1 and second heat exchange unit C2 is
heat transfer portion P1 located in fourth stage S4. Outflow passage OF of each of
20 first heat exchange unit C1 and second heat exchange unit C2 is heat transfer portion
P1 located in first stage S1.
[0055] In first heat exchange region HF1, in each of first heat exchange unit C1 and
second heat exchange unit C2, the plurality of heat transfer portions P1 are connected
by connection portions P2 as follows. Heat transfer portion P1 of first stage S1 is
25 connected to heat transfer portion P1 of second stage S2 on the back side by connection
portion P2. Heat transfer portion P1 of second stage S2 is connected to heat transfer
portion P1 of third stage S3 on the front side by connection portion P2. Heat transfer
portion P1 of third stage S3 is connected to heat transfer portion P1 of fourth stage S4
on the back side by connection portion P2. Heat transfer portion P1 of first stage S1
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of first heat exchange unit C1 is connected to heat transfer portion P1 of fourth stage S4
of second heat exchange unit C2 on the front side by connection portion P2.
[0056] In second heat exchange region HF2, in each of first heat exchange unit C1 and
second heat exchange unit C2, the plurality of heat transfer portions P1 are connected
by connection portions P2 as follows. Heat transfer portion P1 of 5 fourth stage S4 is
connected to heat transfer portion P1 of third stage S3 on the back side by connection
portion P2. Heat transfer portion P1 of third stage S3 is connected to heat transfer
portion P1 of second stage S2 on the front side by connection portion P2. Heat
transfer portion P1 of second stage S2 is connected to heat transfer portion P1 of first
10 stage S1 on the back side by connection portion P2. Heat transfer portion P1 of fourth
stage S4 of first heat exchange unit C1 is connected to heat transfer portion P1 of first
stage S1 of second heat exchange unit C2 on the front side by connection portion P2.
[0057] As indicated by a region A1 in Fig. 8, inflow passages IF of first heat exchange
unit C1 in first heat exchange region HF1 and second heat exchange region HF2 are
15 located adjacent to each other in second direction D2. In the present embodiment,
inflow passages IF of first heat exchange unit C1 in first heat exchange region HF1 and
second heat exchange region HF2 are located in stages adjacent to each other.
[0058] Next, flows of the refrigerant and the air in outdoor heat exchanger 3 will be
described with reference to Figs. 7 and 8.
20 [0059] In first heat exchange region HF1, the refrigerant flows into second heat
exchange unit C2 via inflow passage IF, which is heat transfer portion P1 of first stage
S1 of second heat exchange unit C2. The refrigerant flows from inflow passage IF,
which is heat transfer portion P1 of first stage S1 of second heat exchange unit C2, to
outflow passage OF, which is heat transfer portion P1 of fourth stage S4 of second heat
25 exchange unit C2. Thereafter, the refrigerant flows from outflow passage OF of
second heat exchange unit C2 to inflow passage IF of first heat exchange unit C1.
The refrigerant flows into first heat exchange unit C1 via inflow passage IF, which is
heat transfer portion P1 of first stage S1 of first heat exchange unit C1. The
refrigerant flows from inflow passage IF, which is heat transfer portion P1 of first stage
- 17 -
S1 of first heat exchange unit C1, to outflow passage OF, which is heat transfer portion
P1 of fourth stage S4 of first heat exchange unit C1. Thereafter, the refrigerant flows
out from first heat exchange unit C1. The refrigerant flows through first heat
exchange unit C1 and second heat exchange unit C2 in the form of an inversed N-shape.
[0060] In second heat exchange region HF2, the refrigerant flows 5 into second heat
exchange unit C2 via inflow passage IF, which is heat transfer portion P1 of fourth
stage S4 of second heat exchange unit C2. In second heat exchange unit C2, the
refrigerant flows from inflow passage IF, which is heat transfer portion P1 of fourth
stage S4, to outflow passage OF, which is heat transfer portion P1 of first stage S1.
10 Thereafter, the refrigerant flows from outflow passage OF of second heat exchange unit
C2 to inflow passage IF of first heat exchange unit C1. The refrigerant flows into first
heat exchange unit C1 via inflow passage IF, which is heat transfer portion P1 of fourth
stage S4 of first heat exchange unit C1. In first heat exchange unit C1, the refrigerant
flows from inflow passage IF, which is heat transfer portion P1 of fourth stage S4, to
15 outflow passage OF, which is heat transfer portion P1 of first stage S1. Thereafter,
the refrigerant flows out from first heat exchange unit C1. The refrigerant flows
through first heat exchange unit C1 and second heat exchange unit C2 in the form of an
N-shape.
[0061] In each of first heat exchange region HF1 and second heat exchange region HF2,
20 the refrigerant flows from second heat exchange unit C2 toward first heat exchange unit
C1. The air flows from first heat exchange unit C1 toward second heat exchange unit
C2. Therefore, the flow of the refrigerant flowing through second heat exchange unit
C2 and first heat exchange unit C1 is a counter flow with respect to the flow of the air
flowing through first heat exchange unit C1 and second heat exchange unit C2.
25 [0062] Next, functions and effects of refrigeration cycle apparatus 100 according to the
second embodiment will be described in comparison with a comparative example.
[0063] Referring to Fig. 9, the flow of the refrigerant flowing through first heat
exchange unit C1 and second heat exchange unit C2 in outdoor heat exchanger 3 of the
comparative example for the second embodiment is different from the flow of the
- 18 -
refrigerant flowing through first heat exchange unit C1 and second heat exchange unit
C2 in outdoor heat exchanger 3 of refrigeration cycle apparatus 100 according to the
second embodiment.
[0064] Referring to Fig. 9, in outdoor heat exchanger 3 of the comparative example for
the second embodiment, each of first path PA and second path PB is located 5 in the form
of an inverted N-shape. In other words, first path PA and second path PB are not
located line-symmetrically with respect to each other in second direction D2. As
indicated by a region A1 in Fig. 9, inflow passage IF of first heat exchange unit C1 in
first heat exchange region HF1 is located adjacent to outflow passage OF of first heat
10 exchange unit C1 in second heat exchange region HF2 in second direction D2. Due to
heat conduction by the plurality of fins F, heat exchange is performed between the
refrigerant flowing through inflow passage IF of first heat exchange unit C1 in first
heat exchange region HF1 and the refrigerant flowing through outflow passage OF of
first heat exchange unit C1 in second heat exchange region HF2. This leads to
15 occurrence of thermal loss between first path PA and second path PB.
[0065] On the other hand, according to the refrigeration cycle apparatus of the second
embodiment, referring to Figs. 7 and 8, inflow passages IF of first heat exchange unit
C1 in first heat exchange region HF1 and second heat exchange region HF2 are located
adjacent to each other in second direction D2. Therefore, a temperature difference can
20 be small between the refrigerant flowing through inflow passage IF of first heat
exchange unit C1 in first heat exchange region HF1 and the refrigerant flowing through
inflow passage IF of first heat exchange unit C1 in second heat exchange region HF2.
Therefore, thermal loss between first path PA and second path PB can be small.
[0066] Next, a modification of refrigeration cycle apparatus 100 according to the
25 second embodiment will be described with reference to Fig. 10.
[0067] In the modification of refrigeration cycle apparatus 100 according to the second
embodiment, the number of stages in first heat exchange region HF1 is different from
the number of stages in second heat exchange region HF2. Further, in each of first
heat exchange region HF1 and second heat exchange region HF2, the number of stages
- 19 -
of first heat exchange unit C1 is different from the number of stages of second heat
exchange unit C2. First path PA and second path PB are not located linesymmetrically
with respect to each other in second direction D2.
[0068] In each of first heat exchange region HF1 and second heat exchange region HF2,
inflow passage IF of second heat exchange unit C2 is located in a stage 5 different from
inflow passage IF of first heat exchange unit C1 in second direction D2. Inflow
passage IF of second heat exchange unit C2 is preferably located at a stage displaced by
two stages from inflow passage IF of first heat exchange unit C1.
[0069] In first heat exchange region HF1, the plurality of heat transfer portions P1 are
10 located in first stage S1 to seventh stage S7. In first heat exchange region HF1, inflow
passage IF of second heat exchange unit C2 is heat transfer portion P1 located in first
stage S1. Outflow passage OF of second heat exchange unit C2 is heat transfer
portion P1 located in seventh stage S7. Inflow passage IF of first heat exchange unit
C1 is heat transfer portion P1 located in third stage S3. Outflow passage OF of first
15 heat exchange unit C1 is heat transfer portion P1 located in seventh stage S7.
[0070] In second heat exchange region HF2, the plurality of heat transfer portions P1
are located in first stage S1 to fifth stage S5. In second heat exchange region HF2,
inflow passage IF of second heat exchange unit C2 is heat transfer portion P1 located in
third stage S3. Outflow passage OF of second heat exchange unit C2 is heat transfer
20 portion P1 located in first stage S1. Inflow passage IF of first heat exchange unit C1
is heat transfer portion P1 located in fifth stage S5. Outflow passage OF of first heat
exchange unit C1 is heat transfer portion P1 located in first stage S1.
[0071] According to the modification of refrigeration cycle apparatus 100 of the second
embodiment, in each of first heat exchange region HF1 and second heat exchange
25 region HF2, inflow passage IF of second heat exchange unit C2 is located in a stage
different from inflow passage IF of first heat exchange unit C1 in second direction D2.
Therefore, a degree of freedom of design can be improved.
[0072] Third Embodiment.
A refrigeration cycle apparatus 100 according to a third embodiment has the
- 20 -
same configuration, functions, and effects as those of refrigeration cycle apparatus 100
according to the first embodiment unless otherwise stated particularly.
[0073] The configuration of outdoor heat exchanger 3 in refrigeration cycle apparatus
100 according to the third embodiment will be described with reference to Fig. 11.
[0074] In the third embodiment, in each of first heat exchange unit 5 C1 and second heat
exchange unit C2, the inner diameters of the plurality of heat transfer portions P1 are
different for each stage. In each of first heat exchange unit C1 and second heat
exchange unit C2, the inner diameters of heat transfer portions P1 are smaller in the
order of first stage S1 to fourth stage S4. In each of first heat exchange unit C1 and
10 second heat exchange unit C2, inflow passage IF has an inner diameter larger than an
inner diameter of outflow passage OF.
[0075] Next, functions and effects of refrigeration cycle apparatus 100 according to the
third embodiment will be described.
According to refrigeration cycle apparatus 100 of the third embodiment, in each
15 of first heat exchange unit C1 and second heat exchange unit C2, inflow passage IF has
an inner diameter larger than that of outflow passage OF. In each of first heat
exchange unit C1 and second heat exchange unit C2, the temperature of the refrigerant
in inflow passage IF is higher than the temperature of the refrigerant in outflow passage
OF. Therefore, a temperature difference between the refrigerant and the air is large in
20 inflow passage IF, thus resulting in a large heat exchange amount. On the other hand,
a temperature difference between the refrigerant and the air is small in outflow passage
OF, thus resulting in a small heat exchange amount. Since inflow passage IF has an
inner diameter larger than that of outflow passage OF, heat exchange performance can
be improved.
[0076] Fourth Embodiment.
A refrigeration cycle apparatus 100 according to a fourth embodiment has the
same configuration, functions, and effects as those of refrigeration cycle apparatus 100
according to the second embodiment unless otherwise stated particularly.
[0077] The configuration of outdoor heat exchanger 3 in refrigeration cycle apparatus
100 according to the fourth embodiment will be described with reference to Fig. 12.
[0078] In the fourth embodiment, blower apparatus 6 includes: a fan 6a having a tip
and a root; a boss 6b to which the root of fan 6a is fixed; and a motor 6c to which boss
6b is rotatably connected. Blower apparatus 6 is, for example, a propeller fan.
[0079] Outflow passage OF of each of first heat exchange unit 5 C1 and second heat
exchange unit C2 in first heat exchange region HF1 are located to overlap with the tip
of fan 6a in first direction D1. In other words, outflow passages OF of first heat
exchange unit C1 and second heat exchange unit C2 in first heat exchange region F1
are located to overlap with the tip of fan 6a when viewed in first direction D1.
10 Outflow passages OF of first heat exchange unit C1 and second heat exchange unit C2
in second heat exchange region HF2 are located to overlap with boss 6b and motor 6c
in first direction D1.
[0080] Inflow passages IF of first heat exchange unit C1 and second heat exchange unit
C2 in each of first heat exchange region HF1 and second heat exchange region HF2 are
15 located to overlap with the center between the tip and the root of fan 6a in first
direction D1. For example, the center of fan 6a is a portion that sandwiches a middle
between the tip and root of fan 6a and that falls within a range of 40% or more and 60%
or less of a distance between the tip and root of fan 6a in first direction D1.
[0081] Next, a wind speed distribution of wind generated by blower apparatus 6 will be
20 described. The wind speed distribution is an average wind speed in a direction
(stacking direction) of the stack of the fins. Since each of fan 6a and boss 6b has a
substantially circular shape, when wind speeds are integrated in the direction of the
stack of the fins, a wind speed at tip (outer edge portion) L1 of fan 6a is smaller than a
wind speed at center (central portion) L2 of fan 6a. A wind speed in a central portion
25 L3 of blower apparatus 6 in which boss 6b and motor 6c are located is lower than a
wind speed at center (central portion) L2 of fan 6a. That is, the wind speed at center
(central portion) L2 of fan 6a is larger than each of the wind speeds at tip (outer edge
portion) L1 of fan 6a and central portion L3 of blower apparatus 6.
[0082] Next, functions and effects of refrigeration cycle apparatus 100 according to the
third embodiment will be described.
According to refrigeration cycle apparatus 100 of the fourth embodiment,
inflow passages IF of first heat exchange unit C1 and second heat exchange unit C2 in
each of first heat exchange region HF1 and second heat exchange region HF2 are
located to overlap with the center between the tip and the root 5 of fan 6a in first
direction D1. Therefore, inflow passages IF of first heat exchange unit C1 and second
heat exchange unit C2 can be located to overlap with the center of fan 6a having a large
wind speed (air volume). Therefore, a temperature of blown air can be made low.
[0083] Fifth Embodiment.
10 A refrigeration cycle apparatus 100 according to a fifth embodiment has the
same configuration, functions, and effects as those of refrigeration cycle apparatus 100
according to the second embodiment unless otherwise stated particularly.
[0084] The configuration of outdoor heat exchanger 3 in refrigeration cycle apparatus
100 according to the fifth embodiment will be described with reference to Fig. 13.
15 [0085] In the fifth embodiment, outdoor heat exchanger 3 further includes a sub-cool
line SCL connected to outflow passage OF of first heat exchange unit C1 in each of
first heat exchange region HF1 and second heat exchange region HF2. Sub-cool line
SCL is configured to cool the refrigerant into a super-cooling state. Sub-cool line
SCL is located adjacent to outflow passage OF of first heat exchange unit C1 in first
20 heat exchange region HF1 in second direction D2.
[0086] In the fifth embodiment, outdoor heat exchanger 3 has two pairs of first heat
exchange regions HF1 and second heat exchange regions HF2. A first set ST1 of first
heat exchange region HF1 and second heat exchange region HF2 and a second set ST2
of first heat exchange region HF1 and second heat exchange region HF2 are located in
25 second direction D2. In each of first set ST1 of first heat exchange region HF1 and
second heat exchange region HF2 and second set ST2 of first heat exchange region
HF1 and second heat exchange region HF2, sub-cool line SCL is located opposite to
second heat exchange region HF2 with respect to first heat exchange region HF1 in
second direction D2.
[0087] Each of first set ST1 of first heat exchange region HF1 and second heat
exchange region HF2 and second set ST2 of first heat exchange region HF1 and second
heat exchange region HF2 has a portion R1 at which the temperature of the refrigerant
is high and a portion R1 at which the temperature of the refrigerant is low. Sub-cool
line SCL of second set ST2 of first heat exchange region HF1 5 and second heat
exchange region HF2 is located to be interposed between portions R2 at each of which
the temperature of the refrigerant is low.
[0088] Next, functions and effects of refrigeration cycle apparatus 100 according to the
fifth embodiment will be described in comparison with a comparative example.
10 [0089] Referring to Fig. 14, in a comparative example for the fifth embodiment, each
of first path PA in first heat exchange region HF1 and second path PB in second heat
exchange region HF2 is formed to have a U-shape. Sub-cool line SCL is located
adjacent to inflow passage IF of first heat exchange unit C1 in first heat exchange
region HF1 in second direction D2. Therefore, a temperature difference in the
15 refrigerant is large between first path PA and sub-cool line SCL. This leads to large
thermal loss between first path PA and sub-cool line SCL.
[0090] On the other hand, in refrigeration cycle apparatus 100 according to the fifth
embodiment, sub-cool line SCL is located adjacent to outflow passage OF of first heat
exchange unit C1 in first heat exchange region HF1 in second direction D2. Therefore,
20 a temperature difference in the refrigerant is small between outflow passage OF of first
heat exchange unit C1 in first heat exchange region HF1 and sub-cool line SCL. This
leads to small thermal loss between first path PA and sub-cool line SCL. Therefore, a
heat exchange amount in sub-cool line SCL can be suppressed from being decreased.
[0091] The above-described embodiments may be combined as appropriate.
25 The embodiments disclosed herein are illustrative and non-restrictive in any
respect. The scope of the present disclosure is defined by the terms of the claims,
rather than the embodiments described above, and is intended to include any
modifications within the scope and meaning equivalent to the terms of the claims.
REFERENCE SIGNS LIST
[0092] 1: compressor; 2: four-way valve; 3: outdoor heat exchanger; 4: pressure
reducing valve; 5: indoor heat exchanger; 6, 7: blower apparatus; 6a: fan; 6b: boss; 6c:
motor; 100: refrigeration cycle apparatus; 101: outdoor unit; 102: indoor unit; C1: first
heat exchange unit; C2: second heat exchange unit; CD: controller; D1: first direction;
D2: second direction; D3: third direction; F: fin; HF1: first heat exchange 5 region; HF2:
second heat exchange region; IF: inflow passage; OF: outflow passage; P: heat transfer
tube; P1: heat transfer portion; P2: connection portion; PA: first path; PB: second path;
RC: refrigerant circuit; SCL: sub-cool line.
- 25 -
We Claim:
1. A refrigeration cycle apparatus comprising:
a refrigerant circuit comprising a compressor, a condenser, a pressure reducing
valve, and 5 an evaporator; and
refrigerant circulating through the refrigerant circuit in order of the compressor,
the condenser, the pressure reducing valve, and the evaporator, wherein
the refrigerant is a zeotropic mixed refrigerant,
at least one of the condenser and the evaporator comprises a first heat exchange
10 unit located windward and a second heat exchange unit located leeward in a first
direction in which air flows,
each of the first heat exchange unit and the second heat exchange unit
comprises an inflow passage and an outflow passage for the refrigerant that are located
in a plurality of stages arranged in a second direction crossing the first direction,
15 the refrigerant flows out from the outflow passage of the second heat exchange
unit into the inflow passage of the first heat exchange unit, and
the outflow passage of the second heat exchange unit is located in the same
stage as the outflow passage of the first heat exchange unit in the second direction.
2. The refrigeration cycle apparatus according to claim 1, wherein in each of
the first heat exchange unit and the second heat exchange unit, the inflow passage has
an inner diameter larger than an inner diameter of the outflow passage.
3. The refrigeration cycle apparatus according to claim 1, wherein
25 at least one of the condenser and the evaporator has a first heat exchange region
and a second heat exchange region located in the second direction,
each of the first heat exchange region and the second heat exchange region has
the inflow passage and the outflow passage of each of the first heat exchange unit and
the second heat exchange unit,
in each of the first heat exchange region and the second heat exchange region,
the refrigerant flows out from the outflow passage of the second heat exchange unit
into the inflow passage of the first heat exchange unit,
in each of the first heat exchange region and the second heat exchange region,
the outflow passage of the second heat exchange unit is located in the 5 same stage as the
outflow passage of the first heat exchange unit in the second direction, and
the inflow passages of the first heat exchange unit in the first heat exchange
region and the second heat exchange region are located adjacent to each other in the
second direction.
4. The refrigeration cycle apparatus according to claim 3, wherein in each of
the first heat exchange region and the second heat exchange region, the inflow passage
of the second heat exchange unit is located in a stage different from the inflow passage
of the first heat exchange unit in the second direction.
5. The refrigeration cycle apparatus according to claim 3, further comprising a
blower apparatus, wherein
the blower apparatus comprises a fan having a tip and a root, a boss to which
the root of the fan is fixed, and a motor to which the boss is rotatably connected,
20 the outflow passage of each of the first heat exchange unit and the second heat
exchange unit in the first heat exchange region is located to overlap with the tip of the
fan in the first direction,
the outflow passage of each of the first heat exchange unit and the second heat
exchange unit in the second heat exchange region is located to overlap with the boss
25 and the motor in the first direction, and
the inflow passage of each of the first heat exchange unit and the second heat
exchange unit in each of the first heat exchange region and the second heat exchange
region are located to overlap with a center between the tip and the root of the fan in the
first direction.
6. The refrigeration cycle apparatus according to claim 3, wherein
at least one of the condenser and the evaporator further comprises a sub-cool
line connected to the outflow passage of the first heat exchange unit in each of the first
heat exchange region and the second heat exchange 5 region, and
the sub-cool line is located adjacent to the outflow passage of the first heat
exchange unit in the first heat exchange region in the second direction.