U.S. patent application number 16/078856 was filed with the patent office on 2019-02-28 for refrigeration cycle apparatus.
The applicant listed for this patent is Mitsubishi Electric Corporation. Invention is credited to Yasuhiro SUZUKI, Masahiko TAKAGI, Kenyu TANAKA.
Application Number | 20190063808 16/078856 |
Document ID | / |
Family ID | 60160238 |
Filed Date | 2019-02-28 |
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United States Patent
Application |
20190063808 |
Kind Code |
A1 |
SUZUKI; Yasuhiro ; et
al. |
February 28, 2019 |
REFRIGERATION CYCLE APPARATUS
Abstract
Provided is a refrigeration cycle apparatus, including: a
refrigerant circuit configured to circulate refrigerant having a
flammability; an indoor unit including a casing configured to
accommodate a load-side heat exchanger of the refrigerant circuit;
and a controller configured to control the indoor unit, wherein the
indoor unit includes a refrigerant detection unit and an
air-sending fan, wherein the controller is configured to control
the air-sending fan to operate at an airflow rate Q [m.sup.3/h]
when the refrigerant is detected, and wherein, when a lower
flammability limit of the refrigerant is LFL [kg/m.sup.3] and an
assumed leaking speed of the refrigerant is W [kg/h], the airflow
rate Q, the lower flammability limit LFL, and the assumed leaking
speed W are set to satisfy a relationship of Q>W/LFL.
Inventors: |
SUZUKI; Yasuhiro; (Tokyo,
JP) ; TAKAGI; Masahiko; (Tokyo, JP) ; TANAKA;
Kenyu; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Electric Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
60160238 |
Appl. No.: |
16/078856 |
Filed: |
April 28, 2016 |
PCT Filed: |
April 28, 2016 |
PCT NO: |
PCT/JP2016/063434 |
371 Date: |
August 22, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2500/222 20130101;
F25B 2400/12 20130101; F24F 1/0007 20130101; F25B 2600/11 20130101;
Y02B 30/70 20130101; F24F 11/36 20180101; F24F 11/77 20180101; F25B
49/025 20130101; F25B 49/02 20130101; F24F 11/89 20180101 |
International
Class: |
F25B 49/02 20060101
F25B049/02 |
Claims
1. A refrigeration cycle apparatus, comprising: a refrigerant
circuit configured to circulate refrigerant having a flammability;
an indoor unit including a casing configured to accommodate a
load-side heat exchanger of the refrigerant circuit; and a
controller configured to control the indoor unit, wherein the
indoor unit includes a refrigerant detection unit and an
air-sending fan, wherein the controller is configured to control
the air-sending fan to operate at an airflow rate Q [m.sup.3/h]
when the refrigerant is detected, and wherein, when a lower
flammability limit of the refrigerant is LFL [kg/m.sup.3] and an
assumed leaking speed of the refrigerant is W [kg/h], the airflow
rate Q, the lower flammability limit LFL, and the assumed leaking
speed W are set to satisfy a relationship of Q>W/LFL.
2. The refrigeration cycle apparatus of claim 1, wherein the casing
has an air inlet, an air outlet, and an air passage formed between
the air inlet and the air outlet, and wherein the load-side heat
exchanger, the refrigerant detection unit, and the air-sending fan
are arranged in the air passage, or a space inside the casing which
communicates with the air passage.
3. The refrigeration cycle apparatus of claim 2, further
comprising: a heat source unit configured to accommodate a heat
source-side heat exchanger of the refrigerant circuit; and an
extension pipe, which connects the indoor unit and the heat source
unit to each other, wherein the extension pipe and the load-side
heat exchanger are connected to each other through intermediation
of a joint portion, and wherein the joint portion is arranged in
the air passage, or the space inside the casing which communicates
with the air passage.
4. The refrigeration cycle apparatus of claim 3, wherein the
refrigerant detection unit is arranged below the load-side heat
exchanger or the joint portion.
5. The refrigeration cycle apparatus of claim 1, wherein R32 is
used as the refrigerant, and the airflow rate Q satisfies a
relationship of Q>32.7 [m.sup.3/h].
6. The refrigeration cycle apparatus of claim 1, wherein the indoor
unit comprises an indoor unit of a floor type.
7. An airflow setting method of setting an airflow rate Q in a
refrigeration cycle apparatus, the refrigeration cycle apparatus,
comprising: a refrigerant circuit configured to circulate
refrigerant having a flammability; an indoor unit including a
casing configured to accommodate a load-side heat exchanger of the
refrigerant circuit; and a controller configured to control the
indoor unit, wherein the indoor unit includes a refrigerant
detection unit and an air-sending fan, wherein the controller is
configured to control the air-sending fan to operate at the airflow
rate Q [m.sup.3/h] when the refrigerant is detected, and wherein,
when a lower flammability limit of the refrigerant is LFL
[kg/m.sup.3] and an assumed leaking speed of the refrigerant is W
[kg/h], the airflow rate Q is set so that the airflow rate Q, the
lower flammability limit LFL, and the assumed leaking speed W
satisfy a relationship of Q>W/LFL.
Description
TECHNICAL FIELD
[0001] The present invention relates to a refrigeration cycle
apparatus, which includes a refrigerant detection unit.
BACKGROUND ART
[0002] In Patent Literature 1, there is described an
air-conditioning apparatus. The air-conditioning apparatus includes
a refrigerant detection unit provided on an outer surface of an
indoor unit and configured to detect refrigerant, and a controller
configured to control an indoor air-sending fan to rotate when the
refrigerant detection unit detects the refrigerant. The
air-conditioning apparatus can detect leaked refrigerant by the
refrigerant detection unit when the refrigerant leaks to an indoor
space through an extension pipe connected to the indoor unit or
when refrigerant leaked inside the indoor unit passes through a gap
of a casing of the indoor unit to flow out from the indoor unit.
Further, when the leakage of the refrigerant is detected by the
refrigerant detection unit, the indoor air-sending fan is rotated.
With this action, indoor air is sucked through an air inlet formed
in the casing of the indoor unit, and air is blown off to the
indoor space through an air outlet. In this manner, the leaked
refrigerant can be diffused.
CITATION LIST
Patent Literature
[0003] Patent Literature 1: Japanese Patent No. 4599699
SUMMARY OF INVENTION
Technical Problem
[0004] In Patent Literature 1, however, a rotational speed,
specifically, an airflow rate of the indoor air-sending fan is not
described. Therefore, in a case where the airflow rate which is
required for diffusion of the leaked refrigerant cannot be obtained
even when the indoor air-sending fan is rotated after the
occurrence of leakage of the refrigerant, there is a problem that a
flammable concentration region may be formed in an indoor
space.
[0005] The present invention has been made to solve the problem
described above, and has an object to provide a refrigeration cycle
apparatus capable of inhibiting a flammable concentration region
from being formed in an indoor space in case of leakage of
refrigerant.
Solution to Problem
[0006] According to one embodiment of the present invention, there
is provided a refrigeration cycle apparatus, including: a
refrigerant circuit configured to circulate refrigerant having a
flammability; an indoor unit including a casing configured to
accommodate a load-side heat exchanger of the refrigerant circuit;
and a controller configured to control the indoor unit, wherein the
indoor unit includes a refrigerant detection unit and an
air-sending fan, wherein the controller is configured to control
the air-sending fan to operate at an airflow rate Q [m.sup.3/h]
when the refrigerant is detected, and wherein, when a lower
flammability limit of the refrigerant is LFL [kg/m.sup.3] and an
assumed leaking speed of the refrigerant is W [kg/h], the airflow
rate Q, the lower flammability limit LFL, and the assumed leaking
speed W are set to satisfy a relationship of Q>W/LFL.
Advantageous Effects of Invention
[0007] According to one embodiment of the present invention, when
the refrigerant leaks, the air-sending fan can be operated at a
required airflow rate. Therefore, even when the refrigerant leaks,
the flammable concentration region can be inhibited from being
formed in the indoor space.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is a refrigerant circuit diagram illustrating a
schematic configuration of an air-conditioning apparatus according
to Embodiment 1 of the present invention.
[0009] FIG. 2 is a front view illustrating an outer appearance of
an indoor unit 1 of the air-conditioning apparatus according to
Embodiment 1 of the present invention.
[0010] FIG. 3 is a front view schematically illustrating an
internal structure of the indoor unit 1 of the air-conditioning
apparatus according to Embodiment 1 of the present invention.
[0011] FIG. 4 is a side view schematically illustrating the
internal structure of the indoor unit 1 of the air-conditioning
apparatus according to Embodiment 1 of the present invention.
[0012] FIG. 5 is a flowchart illustrating an example of refrigerant
leakage detection processing executed by a controller 30 of the
air-conditioning apparatus according to Embodiment 1 of the present
invention.
DESCRIPTION OF EMBODIMENTS
Embodiment 1
[0013] A refrigeration cycle apparatus according to Embodiment 1 of
the present invention is described. In Embodiment 1, an
air-conditioning apparatus of a separate type is exemplified as the
refrigeration cycle apparatus. FIG. 1 is a refrigerant circuit
diagram illustrating a schematic configuration of the
air-conditioning apparatus according to Embodiment 1. In FIG. 1 and
the subsequent drawings, for example, a dimensional relationship
and a shape of components are different from actual ones.
[0014] As illustrated in FIG. 1, the air-conditioning apparatus
includes a refrigerant circuit 40 configured to circulate
refrigerant. The refrigerant circuit 40 includes a compressor 3, a
refrigerant flow switching device 4, a heat source-side heat
exchanger 5 (for example, outdoor heat exchanger), a pressure
reducing device 6, and a load-side heat exchanger 7 (for example,
indoor heat exchanger), which are annularly connected through
refrigerant pipes in the stated order. Further, the
air-conditioning apparatus includes, for example, an outdoor unit 2
which is installed outdoors as a heat source unit. Further, the
air-conditioning apparatus includes, for example, an indoor unit 1
which is installed indoors as a load unit. The indoor unit 1 and
the outdoor unit 2 are connected to each other through extension
pipes 10a and 10b forming parts of the refrigerant pipes.
[0015] Examples of refrigerant used as the refrigerant to be
circulated in the refrigerant circuit 40 include a slightly
flammable refrigerant, for example, R32, R1234yf, or R1234ze(E),
and a strongly flammable refrigerant, for example, R290 or R1270.
Those refrigerants may be each used as a single-component
refrigerant, or may be used as a mixed refrigerant obtained by
mixing two or more kinds of the refrigerants with each other. In
the following description, the refrigerant having a flammability
equal to or higher than a slightly flammable level (for example, 2L
or higher in category of ASHRAE34) is often referred to as
"refrigerant having a flammability" or "flammable refrigerant".
Further, as the refrigerant to be circulated in the refrigerant
circuit 40, a nonflammable refrigerant, for example, R22 or R410A,
having a non-flammability (for example, 1 in category of ASHRAE34)
can be used. Those refrigerants have a density larger than that of
air under an atmospheric pressure (for example, a temperature is a
room temperature of 25 degrees Celsius).
[0016] The compressor 3 is a fluid machine configured to compress a
sucked low-pressure refrigerant and to discharge the low-pressure
refrigerant as high-pressure refrigerant. The refrigerant flow
switching device 4 is configured to switch a flow direction of the
refrigerant in the refrigerant circuit 40 between a cooling
operation and a heating operation. As the refrigerant flow
switching device 4, for example, a four-way valve or a plurality of
two way valves is/are used. The heat source-side heat exchanger 5
is a heat exchanger configured to function as a radiator (for
example, condenser) during the cooling operation and to function as
an evaporator during the heating operation. The heat source-side
heat exchanger 5 exchanges heat between the refrigerant flowing
inside the heat source-side heat exchanger 5 and outdoor air sent
by an outdoor air-sending fan 5f described later. The pressure
reducing device 6 is configured to reduce the pressure of the
high-pressure refrigerant such that the high-pressure refrigerant
becomes the low-pressure refrigerant. As the pressure reducing
device 6, for example, an electronic expansion valve having an
opening degree which can be adjusted through control of a
controller 30 described later is used. Further, as the pressure
reducing device 6, a thermal expansion valve, a fixed valve, an
expander, or other devices may be used. The load-side heat
exchanger 7 is a heat exchanger configured to function as an
evaporator during the cooling operation and to function as a
radiator (for example, condenser) during the heating operation. The
load-side heat exchanger 7 exchanges heat between the refrigerant
flowing inside the load-side heat exchanger 7 and air sent by an
indoor air-sending fan 7f described later. In this case, the
cooling operation represents an operation of supplying
low-temperature and low-pressure refrigerant to the load-side heat
exchanger 7, and the heating operation represents an operation of
supplying high-temperature and high-pressure refrigerant to the
load-side heat exchanger 7.
[0017] The outdoor unit 2 accommodates the compressor 3, the
refrigerant flow switching device 4, the heat source-side heat
exchanger 5, and the pressure reducing device 6. Further, the
outdoor unit 2 accommodates the outdoor air-sending fan 5f
configured to supply outdoor air to the heat source-side heat
exchanger 5. The outdoor air-sending fan 5f is installed so as to
face the heat source-side heat exchanger 5. When the outdoor
air-sending fan 5f is rotated, an airflow passing through the heat
source-side heat exchanger 5 is generated. As the outdoor
air-sending fan 5f, for example, a propeller fan is used. The
outdoor air-sending fan 5f is arranged, for example, on downstream
of the heat source-side heat exchanger 5 along the airflow
generated by the outdoor air-sending fan 5f.
[0018] The refrigerant pipes arranged in the outdoor unit 2 include
a refrigerant pipe configured to connect between an extension pipe
connection valve 13a on a side at which the refrigerant becomes a
gas phase during the cooling operation (hereinafter referred to as
the "gas side") and the refrigerant flow switching device 4, a
suction pipe 11 connected to a suction side of the compressor 3, a
discharge pipe 12 connected to a discharge side of the compressor
3, a refrigerant pipe configured to connect between the refrigerant
flow switching device 4 and the heat source-side heat exchanger 5,
a refrigerant pipe configured to connect between the heat
source-side heat exchanger 5 and the pressure reducing device 6,
and a refrigerant pipe configured to connect between an extension
pipe connection valve 13b on a side at which the refrigerant
becomes a liquid phase during the cooling operation (hereinafter
referred to as the "liquid side") and the pressure reducing device
6. The extension pipe connection valve 13a is formed of a two-way
valve capable of switching between open and close, and has one end
to which a joint portion (for example, flare joint) is mounted.
Further, the extension pipe connection valve 13b is formed of a
three-way valve capable of switching between open and close. The
extension pipe connection valve 13b has one end on which a service
port 14a is mounted, which is used at a time of vacuuming being a
preliminary work of filling the refrigerant circuit 40 with
refrigerant, and the other end to which a joint portion (for
example, flare joint) is mounted.
[0019] During both the cooling operation and the heating operation,
high-temperature and high-pressure gas refrigerant compressed by
the compressor 3 flows through the discharge pipe 12. During both
the cooling operation and the heating operation, low-temperature
and low-pressure gas refrigerant or two-phase refrigerant subjected
to an evaporation action flows through the suction pipe 11. The
suction pipe 11 is connected to a low-pressure-side service port
14b with a flare joint, and the discharge pipe 12 is connected to a
high-pressure-side service port 14c with a flare joint. The service
ports 14b and 14c are used to connect a pressure gauge to measure
the operating pressure at a time of installation of the
air-conditioning apparatus or at a time of a trial run for a
repair.
[0020] The load-side heat exchanger 7 is accommodated in the indoor
unit 1. Further, the indoor air-sending fan 7f configured to supply
air to the load-side heat exchanger 7 is installed in the indoor
unit 1. When the indoor air-sending fan 7f is rotated, an airflow
passing through the load-side heat exchanger 7 is generated. As the
indoor air-sending fan 7f, a centrifugal fan (for example, sirocco
fan or turbofan), a cross flow fan, a mixed flow fan, an axial-flow
fan (for example, propeller fan), or other fans is used depending
on a mode of the indoor unit 1. The indoor air-sending fan 7f of
Embodiment 1 is arranged on upstream of the load-side heat
exchanger 7 along the airflow generated by the indoor air-sending
fan 7f, but may be arranged on downstream of the load-side heat
exchanger 7.
[0021] In the indoor unit 1, as refrigerant pipes, a gas-side
indoor pipe 9a and a liquid-side indoor pipe 9b are provided. In a
connection portion of the indoor pipe 9a to the gas-side extension
pipe 10a, a joint portion 15a (for example, flare joint) for
connection to the extension pipe 10a is provided. In a connection
portion of the indoor pipe 9b to the liquid-side extension pipe
10b, a joint portion 15b (for example, flare joint) for connection
to the extension pipe 10b is provided.
[0022] Further, the indoor unit 1 includes, for example, a suction
air temperature sensor 91 configured to detect a temperature of
indoor air sucked from the indoor space, a heat exchanger entrance
temperature sensor 92 configured to detect a refrigerant
temperature at an entrance portion of the load-side heat exchanger
7 during the cooling operation (exit portion during the heating
operation), and a heat exchanger temperature sensor 93 configured
to detect a refrigerant temperature (evaporating temperature or
condensing temperature) of a two-phase portion of the load-side
heat exchanger 7. In addition, the indoor unit 1 includes a
refrigerant detection unit 99 described later. Those sensors are
configured to output a detection signal to the controller 30
configured to control the indoor unit 1 or an entirety of the
air-conditioning apparatus.
[0023] The controller 30 includes a microcomputer including a CPU,
a ROM, a RAM, an I/O port, and a timer. The controller 30 can
perform data communications with an operation unit 26 (see FIG. 2).
The operation unit 26 is configured to receive an operation
performed by a user and output an operation signal based on the
operation to the controller 30. The controller 30 of Embodiment 1
is configured to control the operation of the indoor unit 1 or the
entirety of the air-conditioning apparatus including an operation
of the indoor air-sending fan 7f based on an operation signal
received from the operation unit 26, the detection signal received
from the sensors, or other signals. The controller 30 may be
provided inside a casing of the indoor unit 1, or may be provided
inside a casing of the outdoor unit 2. Further, the controller 30
may include an outdoor unit controller that is provided to the
outdoor unit 2 and an indoor unit controller that is provided to
the indoor unit 1 and capable of performing data communications
with the outdoor unit controller.
[0024] Next, description is made of the operation of the
refrigerant circuit 40 of the air-conditioning apparatus. First,
the operation during the cooling operation is described. In FIG. 1,
the solid arrows indicate flow directions of the refrigerant during
the cooling operation. The refrigerant circuit 40 is configured so
that, during the cooling operation, a refrigerant flow passage is
switched by the refrigerant flow switching device 4 as indicated by
the solid line, and the low-temperature and low-pressure
refrigerant flows into the load-side heat exchanger 7.
[0025] The high-temperature and high-pressure gas refrigerant
discharged from the compressor 3 flows into the heat source-side
heat exchanger 5 after passing through the refrigerant flow
switching device 4. During the cooling operation, the heat
source-side heat exchanger 5 functions as a condenser. That is, the
heat source-side heat exchanger 5 exchanges heat between the
refrigerant flowing inside the heat source-side heat exchanger 5
and the outdoor air sent by the outdoor air-sending fan 5f, and
heat of condensation of the refrigerant is transferred to the
outdoor air. With this operation, the refrigerant that has flowed
into the heat source-side heat exchanger 5 is condensed to become
high-pressure liquid refrigerant. The high-pressure liquid
refrigerant that has flowed out from the heat source-side heat
exchanger 5 flows into the pressure reducing device 6, and is
reduced in pressure to become low-pressure two-phase refrigerant.
The low-pressure two-phase refrigerant that has flowed out from the
pressure reducing device 6 passes through the extension pipe 10b,
and flows into the load-side heat exchanger 7 of the indoor unit 1.
During the cooling operation, the load-side heat exchanger 7
functions as an evaporator. That is, the load-side heat exchanger 7
exchanges heat between the refrigerant flowing inside the load-side
heat exchanger 7 and the indoor air sent by the indoor air-sending
fan 7f, and heat of evaporation of the refrigerant is received from
the indoor air. With this operation, the refrigerant that has
flowed into the load-side heat exchanger 7 evaporates to become
low-pressure gas refrigerant or two-phase refrigerant having high
quality. Further, the air sent by the indoor air-sending fan 7f is
cooled by the refrigerant that receives heat. The low-pressure gas
refrigerant or two-phase refrigerant having high quality, which has
been evaporated by the load-side heat exchanger 7, passes through
the extension pipe 10a and the refrigerant flow switching device 4,
and is sucked by the compressor 3. The refrigerant sucked by the
compressor 3 is compressed to become the high-temperature and
high-pressure gas refrigerant. During the cooling operation, the
above-mentioned cycle is continuously repeated.
[0026] Next, the operation during the heating operation is
described. In FIG. 1, the dotted arrows indicate flow directions of
the refrigerant during the heating operation. The refrigerant
circuit 40 is configured so that, during the heating operation, the
refrigerant flow passage is switched by the refrigerant flow
switching device 4 as indicated by the dotted line, and the
high-temperature and high-pressure refrigerant flows into the
load-side heat exchanger 7.
[0027] The high-temperature and high-pressure gas refrigerant
discharged from the compressor 3 flows into the load-side heat
exchanger 7 of the indoor unit 1 via the refrigerant flow switching
device 4 and the extension pipe 10a. During the heating operation,
the load-side heat exchanger 7 functions as a condenser. That is,
in the load-side heat exchanger 7, heat is exchanged between the
refrigerant flowing inside the load-side heat exchanger 7 and the
indoor air sent by the indoor air-sending fan 7f, and the heat of
condensation of the refrigerant is transferred to the indoor air.
With this operation, the refrigerant that has flowed into the
load-side heat exchanger 7 is condensed to become high-pressure
liquid refrigerant. Further, the indoor air sent by the indoor
air-sending fan 7f is heated by a heat transferring action of the
refrigerant. The high-pressure liquid refrigerant that has flowed
out from the load-side heat exchanger 7 flows into the pressure
reducing device 6 of the outdoor unit 2 via the extension pipe 10b
to be reduced in pressure to become low-pressure two-phase
refrigerant. The low-pressure two-phase refrigerant that has flowed
out from the pressure reducing device 6 flows into the heat
source-side heat exchanger 5. During the heating operation, the
heat source-side heat exchanger 5 functions as the evaporator.
Specifically, the heat source-side heat exchanger 5 exchanges heat
between the refrigerant flowing inside the heat source-side heat
exchanger 5 and the outdoor air sent by the outdoor air-sending fan
5f, and heat of evaporation of the refrigerant is received from the
outdoor air. In this manner, the refrigerant that has flowed into
the heat source-side heat exchanger 5 evaporates to become
low-pressure gas refrigerant or two-phase refrigerant having high
quality. The low-pressure gas refrigerant or the two-phase
refrigerant having high quality, which has flowed out from the heat
source-side heat exchanger 5, is sucked into the compressor 3 via
the refrigerant flow switching device 4. The refrigerant sucked
into the compressor 3 is compressed to become high-temperature and
high-pressure gas refrigerant. During the heating operation, the
above-mentioned cycle is continuously repeated.
[0028] FIG. 2 is a front view illustrating a configuration of an
exterior of the indoor unit 1 of the air-conditioning apparatus
according to Embodiment 1. FIG. 3 is a front view schematically
illustrating an internal structure of the indoor unit 1. FIG. 4 is
a side view schematically illustrating the internal structure of
the indoor unit 1. The left side of FIG. 4 indicates a front
surface side (indoor space side) of the indoor unit 1. In
Embodiment 1, as the indoor unit 1, the indoor unit 1 of a floor
type, which is installed on a floor surface of an indoor space
being an air-conditioned space, is described as an example. In the
following description, positional relationships (for example,
top-bottom relationship) of components are, in principle, exhibited
when the indoor unit 1 is installed in a usable state.
[0029] As illustrated in FIG. 2 to FIG. 4, the indoor unit 1
includes a casing 111 having a vertically elongated cuboid shape.
An air inlet 112 configured to suck air inside the indoor space is
formed in a lower portion of a front surface of the casing 111. The
air inlet 112 of Embodiment 1 is provided below a center portion
along a vertical direction of the casing 111 and at a position
closer to the floor surface. An air outlet 113 configured to blow
off the air sucked from the air inlet 112 indoors is formed in the
upper portion of the front surface of the casing 111, that is, at a
position higher than the air inlet 112 (for example, above the
center portion of the casing 111 along the vertical direction).
Inside the casing 111, an air passage 81 is formed between the air
inlet 112 and the air outlet 113.
[0030] The operation unit 26 is provided to the front surface of
the casing 111 above the air inlet 112 and below the air outlet
113. The operation unit 26 is connected to the controller 30
through a communication line, and is capable of performing data
communications with the controller 30. In the operation unit 26, an
operation start operation, an operation end operation, a switching
operation of an operation mode, a setting operation of a set
temperature and a set airflow rate, and other operations for the
air-conditioning apparatus are performed by a user. The operation
unit 26 includes a display unit or an audio output unit as an
informing unit configured to inform a user of various
information.
[0031] The casing 111 is a hollow box body, and a front opening
part is formed in a front surface of the casing 111. The casing 111
includes a first front panel 114a, a second front panel 114b, and a
third front panel 114c, which are removably mounted to the front
opening part. The first front panel 114a, the second front panel
114b, and the third front panel 114c all have a substantially
rectangular flat outer shape. The first front panel 114a is
removably mounted to a lower part of the front opening part of the
casing 111. In the first front panel 114a, the air inlet 112
described above is formed. The second front panel 114b is arranged
directly above the first front panel 114a, and is removably mounted
to a center part of the front opening part of the casing 111 along
the vertical direction. In the second front panel 114b, the
operation unit 26 described above is provided. The third front
panel 114c is arranged directly above the second front panel 114b,
and is removably mounted to an upper part of the front opening part
of the casing 111. In the third front panel 114c, the air outlet
113 described above is formed.
[0032] An internal space of the casing 111 is divided roughly into
a lower space 115a being an air-sending part and an upper space
115b being a heat-exchanging part located above the lower space
115a. The lower space 115a and the upper space 115b are partitioned
by a partition portion 20. The partition portion 20 has, for
example, a flat shape, and is arranged approximately horizontally.
In the partition portion 20, at least an air passage opening part
20a is formed to serve as an air passage between the lower space
115a and the upper space 115b. The lower space 115a is configured
to be exposed to the front surface side when the first front panel
114a is removed from the casing 111. The upper space 115b is
configured to be exposed to the front surface side when the second
front panel 114b and the third front panel 114c are removed from
the casing 111. That is, the partition portion 20 is mounted at
approximately the same height as that of an upper edge of the first
front panel 114a or a lower edge of the second front panel 114b. In
this case, the partition portion 20 may be formed integrally with a
fan casing 108 described later, may be formed integrally with a
drain pan described later, or may be formed separately from the fan
casing 108 or the drain pan.
[0033] In the air passage 81 within the lower space 115a, there is
arranged the indoor air-sending fan 7f which is configured to cause
a flow of air from the air inlet 112 to the air outlet 113 in the
air passage 81. The indoor air-sending fan 7f of Embodiment 1 is a
sirocco fan including a motor (not shown) and an impeller 107. The
impeller 107 is connected to an output shaft of the motor, and has
a plurality of blades arranged, for example, at regular intervals
along a circumferential direction. A rotary shaft of the impeller
107 is arranged substantially in parallel with a front-and-back
direction of the casing 111. A rotational speed of the indoor
air-sending fan 7f is set variable at multiple levels (for example,
at two or more levels) or variable in a continuous fashion by
control of the controller 30. Specifically, an airflow rate of the
indoor air-sending fan 7f is set variable at multiple levels (for
example, at two or more levels) or variable in a continuous fashion
by control of the controller 30.
[0034] The impeller 107 of the indoor air-sending fan 7f is covered
with the fan casing 108 having a spiral shape. The fan casing 108
is formed, for example, separately from the casing 111. A suction
opening part 108b for sucking the indoor air through the air inlet
112 into the fan casing 108 is formed near the center of a spiral
of the fan casing 108. The suction opening part 108b is located so
as to face the air inlet 112. Further, an air outlet opening part
108a for blowing off the sent air is formed along a direction of a
tangential line of the spiral of the fan casing 108. The air outlet
opening part 108a is arranged so as to be oriented upward, and is
connected to the upper space 115b through the air passage opening
part 20a of the partition portion 20. In other words, the air
outlet opening part 108a communicates with the upper space 115b
through the air passage opening part 20a. An opening end of the air
outlet opening part 108a and an opening end of the air passage
opening part 20a may be directly connected to each other, or may be
indirectly connected to each other through a duct member or other
parts.
[0035] Further, in the lower space 115a, there is provided an
electrical component box 25 accommodating, for example, a
microcomputer that forms the controller 30, various electrical
components, and a board.
[0036] The load-side heat exchanger 7 is arranged in the air
passage 81 within the upper space 115b. The indoor pipes 9a and 9b
are connected to the load-side heat exchanger 7. The indoor pipes
9a and 9b pass through the partition portion 20 to extend from the
upper space 115b into the lower space 115a and are respectively
connected to the extension pipes 10a and 10b through intermediation
of the joint portions 15a and 15b in the lower space 115a. The
joint portions 15a and 15b are arranged in the air passage 81, or a
space inside the casing 111 which communicates with the air passage
81. The drain pan (not shown) configured to receive condensed water
that is condensed on a surface of the load-side heat exchanger 7 is
provided below the load-side heat exchanger 7. The drain pan may be
formed as a part of the partition portion 20, or may be formed
separately from the partition portion 20 and arranged on the
partition portion 20.
[0037] The refrigerant detection unit 99 configured to detect the
leakage of the refrigerant is provided in the air passage 81, or
the space inside the casing 111 which communicates with the air
passage 81. As the refrigerant detection unit 99, a gas sensor such
as a semiconductor gas sensor or a hot-wire type semiconductor gas
sensor is used. The refrigerant detection unit 99 is configured to
detect, for example, a refrigerant concentration in the air around
the refrigerant detection unit 99, and to output the detection
signal to the controller 30. The controller 30 determines presence
or absence of leakage of the refrigerant based on the detection
signal received from the refrigerant detection unit 99. Further, as
the refrigerant detection unit 99, an oxygen concentration meter
may be used, or a temperature sensor (for example, a thermistor)
may be used. When the temperature sensor is used as the refrigerant
detection unit 99, the refrigerant detection unit 99 detects the
leakage of the refrigerant by detecting a reduction in temperature
due to adiabatic expansion of the leaked refrigerant.
[0038] The refrigerant used in Embodiment 1 has a larger density
than air under the atmospheric pressure. Therefore, it is desired
that the refrigerant detection unit 99 be provided in a lower part
inside the casing 111 (for example, a lowermost part inside the
casing 111). In this example, the refrigerant detection unit 99 is
provided in a lower part of the lower space 115a to fall within a
height range from a height which is equal to or lower than a height
of an opening lower end 112a of the air inlet 112 to a height which
is equal to or higher than a height of a bottom surface portion
111a of the casing 111 (see FIG. 4). In this case, the opening
lower end 112a of the air inlet 112 is positioned above the bottom
surface portion 111a of the casing 111. In a bottom portion of the
lower space 115a, which falls within the above-mentioned height
range, a recessed portion having a small volume with an upwardly
oriented opening is formed. When the refrigerant having a larger
density than air under the atmospheric pressure is used, only small
part of the refrigerant leaked inside the casing 111 stagnates in
the recessed portion without flowing out from the casing 111.
Therefore, through the arrangement of the refrigerant detection
unit 99 in the recessed portion, the leakage of the refrigerant can
be more reliably detected. The amount of refrigerant stagnating in
the recessed portion is very small, and, at the same time, no
ignition source such as an electrical component is provided in the
recessed portion. Therefore, there is no fear of unexpected
ignition.
[0039] As described above, the load-side heat exchanger 7, the
indoor air-sending fan 7f, and the refrigerant detection unit 99
are all arranged in the air passage 81, or the space inside the
casing 111 which communicates with the air passage 81. Further, the
refrigerant detection unit 99 is arranged below the load-side heat
exchanger 7.
[0040] Further, in Embodiment 1, the joint portions 15a and 15b are
also arranged in the air passage 81, or the space inside the casing
111 which communicates with the air passage 81. The refrigerant
detection unit 99 is arranged below the joint portions 15a and
15b.
[0041] In the indoor unit 1, leakage of refrigerant is liable to
occur in the load-side heat exchanger 7 (in particular, at a brazed
portion of the load-side heat exchanger 7) and at the joint
portions 15a and 15b. Further, the refrigerant used in Embodiment 1
has a density larger than that of the air under the atmospheric
pressure. Hence, the refrigerant detection unit 99 of Embodiment 1
is provided in the space inside the casing 111, which communicates
with the space in which the load-side heat exchanger 7 and the
joint portions 15a and 15b are provided and arranged at a position
lower in height than the load-side heat exchanger 7 and the joint
portions 15a and 15b. With this arrangement, the refrigerant
detection unit 99 can reliably detect the leaked refrigerant when
the refrigerant leaks at least while the indoor air-sending fan 7f
is in a stopped state. In Embodiment 1, the refrigerant detection
unit 99 is provided at the position in the lower part of the lower
space 115a, but the refrigerant detection unit 99 may be arranged
at another position.
[0042] FIG. 5 is a flowchart illustrating an example of the flow of
the refrigerant leakage detection processing executed by the
controller 30 of the air-conditioning apparatus according to
Embodiment 1. The refrigerant leakage detection processing is
executed repeatedly at predetermined time intervals at all times
including while the air-conditioning apparatus is operating and is
stopped, or only while the air-conditioning apparatus is
stopped.
[0043] In Step S1 of FIG. 5, the controller 30 acquires information
on the refrigerant concentration around the refrigerant detection
unit 99 based on the detection signal received from the refrigerant
detection unit 99.
[0044] Next, in Step S2, the controller 30 determines whether or
not the refrigerant concentration around the refrigerant detection
unit 99 is equal to or larger than a threshold value set in
advance. When the controller 30 determines that the refrigerant
concentration is equal to or larger than the threshold value, the
processing proceeds to Step S3. When the controller 30 determines
that the refrigerant concentration is smaller than the threshold
value, the processing is terminated.
[0045] In Step S3, the controller 30 starts the operation of the
indoor air-sending fan 7f. The airflow rate of the indoor
air-sending fan 7f is set to a predetermined airflow rate Q. A
settable range of the airflow rate Q is described later.
Information of the airflow rate Q or information of the rotational
speed of the indoor air-sending fan 7f for obtaining the airflow
rate Q is stored in advance in the ROM of the controller 30. When
the indoor air-sending fan 7f is already operated at an airflow
rate equal to or larger than the airflow rate Q, the operation is
continued without any change. When the indoor air-sending fan 7f is
operated at an airflow rate smaller than the airflow rate Q, the
airflow rate of the indoor air-sending fan 7f is increased to the
airflow rate Q. When the indoor air-sending fan 7f is stopped, the
indoor air-sending fan 7f is activated to operate the indoor
air-sending fan 7f at the rotational speed which enables the
airflow rate Q to be obtained. In Step S3, the display unit, the
audio output unit, or other units provided in the operation unit 26
may be used to inform a user that the leakage of the refrigerant
has occurred. Further, the indoor air-sending fan 7f that has
started to operate in Step S3 may be stopped after elapse of a
predetermined time period set in advance.
[0046] As described above, in the refrigerant leakage detection
processing, when the leakage of the refrigerant is detected (that
is, when the refrigerant concentration detected by the refrigerant
detection unit 99 is equal to or larger than the threshold value),
the operation of the indoor air-sending fan 7f is forcibly started.
With this operation, it is possible to diffuse the leaked
refrigerant.
[0047] As described above, in Embodiment 1, examples of the
refrigerant to be circulated in the refrigerant circuit 40 include
flammable refrigerants such as R32, R1234yf, R1234ze(E), R290, and
R1270. Therefore, in case of leakage of refrigerant in the indoor
unit 1, there is a fear that the indoor refrigerant concentration
is increased to form a flammable concentration region (for example,
region in which the refrigerant concentration is equal to or larger
than the lower flammability limit (LFL)).
[0048] Those flammable refrigerants have a density larger than that
of air under the atmospheric pressure. Therefore, when the leakage
of the refrigerant occurs at a position at which the height from
the floor surface of the indoor space is relatively large, the
leaked refrigerant is diffused during descending. Thus, the
refrigerant concentration becomes uniform in the indoor space, and
hence the refrigerant concentration is less liable to be increased.
In contrast, when the leakage of the refrigerant occurs at a
position at which the height from the floor surface of the indoor
space is small, the leaked refrigerant remains at a low position
near the floor surface, and hence the refrigerant concentration
tends to be locally increased. As a result, when the leakage of the
flammable refrigerant occurs in the indoor unit 1 of, in
particular, a floor type, the risk of formation of the flammable
concentration region is relatively increased as compared to a case
in which the leakage of the flammable refrigerant occurs in an
indoor unit of a type other than the floor type.
[0049] While the air-conditioning apparatus is operated, air is
blown off to the indoor space due to the operation of the indoor
air-sending fan 7f of the indoor unit 1. Therefore, even when the
flammable refrigerant leaks to the indoor space, the leaked
flammable refrigerant is diffused in the indoor space by the air
being blown off. In this manner, the flammable concentration region
can be inhibited from being formed in the indoor space. However,
while the air-conditioning apparatus is stopped, the indoor
air-sending fan 7f of the indoor unit 1 is also stopped, and hence
the leaked refrigerant cannot be diffused by the air being blown
off. Therefore, detection of the leaked refrigerant is more
required while the air-conditioning apparatus is stopped. In
Embodiment 1, the operation of the indoor air-sending fan 7f is
started when the leakage of the refrigerant is detected, and hence
the flammable concentration region can be inhibited from being
formed in the indoor space even when the flammable refrigerant
leaks to the indoor space while the air-conditioning apparatus is
stopped.
[0050] In Embodiment 1, the portions having the risk of occurrence
of leakage of the refrigerant are all arranged in the air passage
81, or the space inside the casing 111 which communicates with the
air passage 81. Further, the refrigerant detection unit 99 is
arranged in the air passage 81, or the space that is inside the
casing 111 and communicates with the air passage 81 and, at the
same time, is arranged below the portion having the risk of
occurrence of the leakage of the refrigerant. Therefore, when the
leakage of the refrigerant occurs, the leaked refrigerant can be
reliably detected by the refrigerant detection unit 99 before the
leaked refrigerant flows out from the casing 111 of the indoor unit
1. Further, when the leakage of the refrigerant occurs, the
operation of the indoor air-sending fan 7f can be started before
the leaked refrigerant flows out from the casing 111 of the indoor
unit 1.
[0051] When the operation of the indoor air-sending fan 7f is
started, the leaked refrigerant is mixed with the air sucked into
the air passage 81 from the air inlet 112 and is then blown off as
refrigerant mixed air into the indoor space from the air outlet
113. The refrigerant contained in the blown-off refrigerant mixed
air is gradually diffused in the indoor space. Specifically, in the
indoor space outside the casing 111, the refrigerant concentration
becomes the highest in the refrigerant mixed air blown off from the
air outlet 113. Therefore, when the refrigerant concentration in
the refrigerant mixed air that is blown off from the air outlet 113
is smaller than a lower flammability limit LFL, the flammable
concentration region is not formed in the indoor space in which the
indoor unit 1 is installed. This is because the refrigerant
concentration is not increased without application of an external
force.
[0052] Therefore, in Embodiment 1, the airflow rate Q [m.sup.3/h]
of the indoor air-sending fan 7f given when the leakage of the
refrigerant is detected to forcibly operate the indoor air-sending
fan 7f is set to satisfy a relationship expressed by Expression (1)
below. In Expression (1), the lower flammability limit of the
refrigerant is LFL [kg/m.sup.3], and an assumed leaking speed of
the refrigerant is W [kg/h]. An upper limit of the airflow rate Q
corresponds to a maximum airflow rate of the indoor air-sending fan
7f.
Q>W/LFL (1)
[0053] The assumed leaking speed W represents a mass of the
refrigerant (at the concentration of 100%) leaked into the air
passage 81 per unit time. The airflow rate Q represents a volume of
air moving inside the air passage 81 per unit time, specifically, a
volume of air sucked from the air inlet 112 or a volume of air
blown off from the air outlet 113. Specifically, the refrigerant
concentration in the refrigerant mixed air moving inside the air
passage 81 is a value W/Q obtained by dividing the assumed leaking
speed W by the airflow rate Q. When the value W/Q is smaller than
the lower flammability limit (W/Q<LFL), the refrigerant
concentration in the refrigerant mixed air blown off from the air
outlet 113 becomes smaller than the lower flammability limit LFL.
Therefore, through setting of the airflow rate Q to satisfy
Expression (1), the refrigerant concentration in the refrigerant
mixed air blown off from the air outlet 113 can be set smaller than
the lower flammability limit LFL. In this manner, even when the
leakage of the refrigerant occurs, the flammable concentration
region can be inhibited from being formed in the indoor space.
[0054] A specific example of the range of the airflow rate Q is
described, taking the use of R32 as the refrigerant as an example.
The lower flammability limit LFL of R32 is 0.306 kg/m.sup.3.
[0055] The assumed leaking speed W is now examined. In the
literature "Overview of the risk assessment and the safety
guideline for VRF system using A2L refrigerants", The international
Symposium on New Refrigerants and Environmental Technology 2014,
November 2014, The Japan Refrigeration and Air Conditioning
Industry Association, pages 234 to 240, it is described that,
according to ISO 5149-1 Annex A.5, 10 kg/h is adopted as the
refrigerant leaking speed in the indoor unit on the condition that
there is no source of vibration such as a compressor. Further, in
the literature mentioned above, there is described that, as results
of measurements of the refrigerant leaking speed on twenty two
leakage components for the indoor unit, which had been recalled
from the market, three leakage components had a relatively high
leaking speed of from about 1 kg/h to 10 kg/h and the remaining
eighteen leakage components had a small leaking speed ranging from
about 0.005 kg/h to about 0.5 k/h. According to the descriptions
given above, based on any of ISO and the results of actual
measurements, it is understood that 10 kg/h can be used as the
assumed leaking speed W for the indoor unit without the
compressor.
[0056] Therefore, when R32 is used as the refrigerant, the lower
flammability limit LFL is 0.306 kg/m.sup.3 and the assumed leaking
speed W is 10 kg/h. Hence, when the airflow rate Q is set to
satisfy Expression (2), the flammable concentration region can be
inhibited from being formed in the indoor space.
Q>10 [kg/h]/0.306 [kg/m.sup.3]=32.7 [m.sup.3/h]=0.545
[m.sup.3/min] (2)
[0057] Even when a refrigerant other than R32 is used, the airflow
rate Q can be obtained in the same manner as described above by
using the lower flammability limit of the refrigerant.
[0058] When R1234yf (lower flammability limit: 0.289 kg/m.sup.3) is
used as the refrigerant, the flammable concentration region can be
inhibited from being formed in the indoor space by setting the
airflow rate Q to satisfy Expression (3).
Q>10 [kg/h]/0.289 [kg/m.sup.3]=34.6 [m.sup.3/h]=0.577
[m.sup.3/min] (3)
[0059] When R290 (lower flammability limit: 0.038 kg/m.sup.3) is
used as the refrigerant, the flammable concentration region can be
inhibited from being formed in the indoor space by setting the
airflow rate Q to satisfy Expression (4).
Q>10 [kg/h]/0.038 [kg/m.sup.3]=263 [m.sup.3/h]=4.39
[m.sup.3/min] (4)
[0060] When R1270 (lower flammability limit: 0.043 kg/m.sup.3) is
used as the refrigerant, the flammable concentration region can be
inhibited from being formed in the indoor space by setting the
airflow rate Q to satisfy Expression (5).
Q>10 [kg/h]/0.043 [kg/m.sup.3]=233 [m.sup.3/h]=3.88
[m.sup.3/min] (5)
[0061] Even when a refrigerant other than those described above is
used, the airflow rate Q can be obtained in the same manner.
[0062] As described above, the refrigeration cycle apparatus
according to Embodiment 1 includes the refrigerant circuit 40
configured to circulate the refrigerant having a flammability, the
indoor unit 1 including the casing 111 configured to accommodate
the load-side heat exchanger 7 of the refrigerant circuit 40, and
the controller 30 configured to control the indoor unit 1. The
indoor unit 1 includes the refrigerant detection unit 99 and the
indoor air-sending fan 7f which are accommodated in the casing 111.
The controller 30 is configured to control the indoor air-sending
fan 7f to operate at the airflow rate Q [m.sup.3/h] when the
refrigerant is detected. When the lower flammability limit of the
refrigerant is LFL [kg/m.sup.3] and the assumed leaking speed of
the refrigerant is W [kg/h], the airflow rate Q, the lower
flammability limit LFL, and the assumed leaking speed W are set to
satisfy the relationship of Q>W/LFL.
[0063] According to the configuration described above, when the
refrigerant leaks, the indoor air-sending fan 7f can be operated at
the airflow rate which is required for diffusion of the leaked
refrigerant. Therefore, in case of leakage of the refrigerant, the
flammable concentration region can be inhibited from being formed
in the indoor space.
[0064] Further, in the refrigeration cycle apparatus according to
Embodiment 1, the casing 111 may have the air inlet 112, the air
outlet 113, and the air passage 81 formed between the air inlet 112
and the air outlet 113. The load-side heat exchanger 7, the
refrigerant detection unit 99, and the indoor air-sending fan 7f
may be arranged in the air passage 81, or in the space inside the
casing 111 which communicates with the air passage 81. According to
the configuration described above, when the leakage of the
refrigerant occurs in the load-side heat exchanger 7, the leakage
of the refrigerant can be reliably detected by the refrigerant
detection unit 99.
[0065] Further, the refrigeration cycle apparatus according to
Embodiment 1 may further include the outdoor unit 2 (an example of
the heat source unit) configured to accommodate the heat
source-side heat exchanger 5 of the refrigerant circuit 40 and the
extension pipes 10a and 10b which connect the indoor unit 1 and the
outdoor unit 2 each other. The extension pipes 10a and 10b and the
load-side heat exchanger 7 may be connected through intermediation
of the joint portions 15a and 15b, respectively, and the joint
portions 15a and 15b may be arranged in the air passage 81, or the
space inside the casing 111 which communicates with the air passage
81. According to the configuration described above, when the
leakage of the refrigerant occurs at the joint portions 15a and
15b, the leakage of the refrigerant can be reliably detected by the
refrigerant detection unit 99.
[0066] Further, in the refrigeration cycle apparatus according to
Embodiment 1, the refrigerant detection unit 99 may be arranged
below the load-side heat exchanger 7 or the joint portions 15a and
15b. According to the configuration described above, the leakage of
the refrigerant can be more reliably detected by the refrigerant
detection unit 99.
[0067] Further, in the refrigeration cycle apparatus according to
Embodiment 1, R32 may be used as the refrigerant, and the airflow
rate Q may satisfy the relationship of Q>32.7 [m.sup.3/h].
According to the configuration described above, when R32 is used as
the refrigerant, the flammable concentration region can be
inhibited from being formed in the indoor space.
[0068] Further, in the refrigeration cycle apparatus according to
Embodiment 1, the indoor unit 1 may be of a floor type. According
to the configuration described above, even in the indoor unit of a
floor type in which the position at which the refrigerant leaks is
liable to be low in height from the floor surface, the flammable
concentration region can be inhibited from being formed in the
indoor space.
[0069] Further, the airflow rate setting method according to
Embodiment 1 is a method of setting the airflow rate Q in the
refrigeration cycle apparatus including the refrigerant circuit 40
configured to circulate the refrigerant having a flammability, the
indoor unit 1 including the casing 111 configured to accommodate
the load-side heat exchanger 7 of the refrigerant circuit 40, and
the controller 30 configured to control the indoor unit 1. The
indoor unit 1 includes the refrigerant detection unit 99 and the
indoor air-sending fan 7f which are accommodated in the casing 111.
The controller 30 is configured to control the indoor air-sending
fan 7f to operate at the airflow rate Q [m.sup.3/h] when the
refrigerant is detected. When the lower flammability limit of the
refrigerant is LFL [kg/m.sup.3] and the assumed leaking speed of
the refrigerant is W [kg/h], the airflow rate Q is set so that the
airflow rate Q, the lower flammability limit LFL, and the assumed
leaking speed W to satisfy the relationship of Q>W/LFL.
[0070] According to the configuration described above, when the
refrigerant leaks, the indoor air-sending fan 7f can be operated at
the airflow rate which is required for diffusion of the leaked
refrigerant. Therefore, even when the refrigerant leaks, the
flammable concentration region can be inhibited from being formed
in the indoor space.
Other Embodiments
[0071] The present invention is not limited to the embodiment
above, and various modifications may be made thereto.
[0072] For example, in the embodiment above, description is made of
the indoor unit of a floor type as an example. However, the present
invention can be applied to other indoor units of, for example, a
ceiling-mounted cassette type, a ceiling-concealed type, a
ceiling-suspended type, and a wall-hung type.
[0073] Further, in the embodiment above, description is made of the
indoor unit which includes the load-side heat exchanger arranged in
the upper part inside the casing and the indoor air-sending fan
arranged in the lower part inside the casing as an example.
However, the present invention is not limited thereto. The indoor
unit may include the load-side heat exchanger arranged in the lower
part inside the casing and the indoor air-sending fan arranged in
the upper part inside the casing, or the indoor unit may include
the load-side heat exchanger and the indoor air-sending fan which
are arranged side by side in a horizontal direction of the indoor
unit.
[0074] Further, in the embodiment above, description was made of
the refrigeration cycle apparatus as an example of the
air-conditioning apparatus. However, the present invention can also
be applied to other refrigeration cycle apparatuses such as a heat
pump water heater (for example, heat pump water heater described in
Japanese Patent Application Laid-open No. 2016-3783), a chiller and
a showcase, or a refrigeration cycle system.
REFERENCE SIGNS LIST
[0075] 1 indoor unit 2 outdoor unit 3 compressor 4 refrigerant flow
switching device 5 heat source-side heat exchanger 5f outdoor
air-sending fan
[0076] 6 pressure reducing device 7 load-side heat exchanger 7f
indoor air-sending fan 9a, 9b indoor pipe 10a, 10b extension pipe
11 suction pipe 12 discharge pipe 13a, 13b extension pipe
connecting valve 14a, 14b, 14c service port 15a, 15b joint portion
20 partition portion 20a air passage opening part 25 electrical
component box 26 operation unit 30 controller 40 refrigerant
circuit 81 air passage 91 suction air temperature sensor 92 heat
exchanger entrance temperature sensor 93 heat exchanger temperature
sensor 99 refrigerant detection unit 107 impeller 108 fan casing
108a air outlet opening part 108b suction opening part 111 casing
111a bottom surface portion 112 air inlet 112a opening lower end
113 air outlet 114a first front panel 114b second front panel
[0077] 114c third front panel 115a lower space 115b upper space
* * * * *