U.S. patent application number 14/769925 was filed with the patent office on 2016-01-07 for air-conditioning apparatus.
This patent application is currently assigned to Mitsubishi Electric Corporation. The applicant listed for this patent is Takayoshi HONDA, Osamu MORIMOTO, Yuji MOTOMURA, Koji NISHIOKA, Tatsuo ONO, Daisuke SHIMAMOTO. Invention is credited to Takayoshi HONDA, Osamu MORIMOTO, Yuji MOTOMURA, Koji NISHIOKA, Tatsuo ONO, Daisuke SHIMAMOTO.
Application Number | 20160003490 14/769925 |
Document ID | / |
Family ID | 51390784 |
Filed Date | 2016-01-07 |
United States Patent
Application |
20160003490 |
Kind Code |
A1 |
MOTOMURA; Yuji ; et
al. |
January 7, 2016 |
AIR-CONDITIONING APPARATUS
Abstract
For each of a plurality of use-side heat exchangers, a plurality
of heat medium flow switching devices respectively corresponding to
the plurality of use-side heat exchangers are entirely or partially
integrated, and the thus obtained integrated heat medium flow
switching device is driven by a single driving device.
Inventors: |
MOTOMURA; Yuji; (Tokyo,
JP) ; SHIMAMOTO; Daisuke; (Tokyo, JP) ; HONDA;
Takayoshi; (Tokyo, JP) ; MORIMOTO; Osamu;
(Tokyo, JP) ; NISHIOKA; Koji; (Tokyo, JP) ;
ONO; Tatsuo; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MOTOMURA; Yuji
SHIMAMOTO; Daisuke
HONDA; Takayoshi
MORIMOTO; Osamu
NISHIOKA; Koji
ONO; Tatsuo |
Chiyoda-ku, Tokyo
Chiyodo-ku, Tokyo
Chiyoda-ku, Tokyo
Chiyoda-ku, Tokyo
Chiyoda-ku, Tokyo |
|
JP
JP
JP
US
JP
JP |
|
|
Assignee: |
Mitsubishi Electric
Corporation
Tokyo
JP
|
Family ID: |
51390784 |
Appl. No.: |
14/769925 |
Filed: |
February 25, 2013 |
PCT Filed: |
February 25, 2013 |
PCT NO: |
PCT/JP2013/054751 |
371 Date: |
August 24, 2015 |
Current U.S.
Class: |
62/196.1 |
Current CPC
Class: |
F25B 2313/02741
20130101; F25B 2313/0315 20130101; F25B 2313/02732 20130101; F25B
2700/21174 20130101; F24F 3/065 20130101; F25B 2700/21152 20130101;
F25B 13/00 20130101; F25B 2313/0314 20130101; F25B 2700/21175
20130101; F16K 11/085 20130101; F25B 2500/26 20130101; F25B
2313/0312 20130101; F25B 2700/21173 20130101; F25B 2700/21161
20130101; F25B 49/02 20130101; F25B 2313/0231 20130101; F25B
2600/2513 20130101; F25B 25/005 20130101; F25B 2700/1931 20130101;
F25B 2700/1933 20130101; F25B 2700/21151 20130101; F25B 2700/21163
20130101; F25B 2700/21162 20130101; F24F 1/32 20130101; F24F 5/001
20130101; F25B 2313/003 20130101; F25B 2500/19 20130101 |
International
Class: |
F24F 5/00 20060101
F24F005/00 |
Claims
1. An air-conditioning apparatus, comprising: a refrigerant circuit
formed by connecting a compressor, a heat source-side heat
exchanger, a plurality of expansion devices, and refrigerant-side
passages in a plurality of intermediate heat exchangers by
refrigerant pipes to allow heat source-side refrigerant to
circulate therethrough; a plurality of heat medium circuits formed
by connecting a plurality of pumps, a plurality of use-side heat
exchangers, and heat medium-side passages in the plurality of
intermediate heat exchangers by heat-medium pipes to allow a heat
medium to circulate therethrough; a plurality of heat medium flow
switching devices provided correspondingly to each of the plurality
of use-side heat exchangers, and the plurality of heat medium flow
switching devices configured to switch a passage for the heat
medium by connecting the use-side heat exchangers to any one of the
plurality of intermediate heat exchangers, the plurality of
use-side heat exchangers being individually connected to any one of
the plurality of intermediate heat exchangers to enable a heating
operation or a cooling operation; and an integrated heat medium
flow switching device formed by entirely or partially integrating
the plurality of heat medium flow switching devices, the integrated
heat medium flow switching device being provided for each of the
plurality of use-side heat exchangers, the integrated heat medium
flow switching device being configured to switch the passage for
the heat medium depending on a rotation stop position of a valve
body, and the integrated heat medium flow switching device being
configured to control a flow rate of the heat medium flowing into
the corresponding use-side heat exchanger of the use-side heat
exchangers depending on a rotation stop position of the valve body,
and the integrated heat medium flow switching device being driven
by a single driving device.
2. The air-conditioning apparatus of claim 1, wherein the
integrated heat medium flow switching device comprises a pair of
heat medium delivery main pipes, which is provided to the each of
the plurality of intermediate heat exchangers, and serves as a
passage between the intermediate heat exchanger and any one of the
plurality of use-side heat exchangers, a body having a valve
chamber intersecting a plurality of the pairs of heat medium
delivery main pipes, and the valve body having a shaft-like shape
and arranged in the valve chamber so as to be axially rotatable,
the valve body comprises a pair of selection-side openings to be
brought into communication with any one of the plurality of the
pairs of heat medium delivery main pipes depending on a rotation
stop position of the valve body, an indoor unit-side inlet opening
to be connected to an inlet side of a corresponding use-side heat
exchanger of the use-side heat exchangers, and a plurality of
indoor unit-side outlet openings to be brought into communication
with an outlet side of the corresponding use-side heat exchanger of
the use-side heat exchangers in a state in which the pair of
selection-side openings is held in communication with each of the
plurality of the pairs of heat medium delivery main pipes, and the
valve body formed therein a supply passage for bringing one of the
pair of selection-side openings and the indoor unit-side inlet
opening into communication with each other, and a plurality of
selective return passages for connecting each of the plurality of
indoor unit-side outlet openings and an other of the pair of
selection-side openings to each other.
3. The air-conditioning apparatus of claim 2, wherein the pair of
selection-side openings and the plurality of indoor unit-side
outlet openings are formed in an outer peripheral surface of the
valve body, the indoor unit-side inlet opening is formed in an
axial end portion of the valve body, and the valve body further
includes an adiabatic wall formed between the supply passage and
the plurality of selective return passages.
4. The air-conditioning apparatus of claim 2, wherein the valve
body controls a flow rate of the heat medium flowing into the
corresponding use-side heat exchanger of the use-side heat
exchangers by a change in communicating area between the pair of
selection-side openings and the pair of heat medium delivery main
pipes depending on the rotation stop position of the valve
body.
5. The air-conditioning apparatus of claim 2, wherein the valve
body separates the corresponding use-side heat exchanger of the
use-side heat exchangers from the heat medium circuit by stopping
at a rotation stop position at which the pair of selection-side
openings is not brought into communication with any one of the
plurality of the pairs of heat medium delivery main pipes.
6. The air-conditioning apparatus of claim 1, wherein the
air-conditioning apparatus operates a heating only operation mode
in which all the plurality of intermediate heat exchangers function
as condensers, a cooling only operation mode in which all the
plurality of intermediate heat exchangers function as evaporators,
and a cooling and heating mixed operation mode in which some of the
plurality of intermediate heat exchangers function as the
condensers and other some of the plurality of intermediate heat
exchangers function as the evaporators, wherein, in the cooling and
heating mixed operation mode, when the use-side heat exchanger of
the use-side heat exchangers is switched from one of cooling to
heating and heating to cooling, the driving device corresponding to
the use-side heat exchanger of the use-side heat exchangers for
which the operation is switched is driven to switch the passage for
the heat medium.
7. The air-conditioning apparatus of claim 1, wherein the heat
source-side refrigerant comprises any one of a single-component
refrigerant, a near-azeotropic refrigerant mixture, a zeotropic
refrigerant mixture, a refrigerant with a two-phase change
including a natural refrigerant, and a refrigerant that turns into
a supercritical state.
8. The air-conditioning apparatus of claim 1, wherein the heat
medium comprises any one of an antifreezing solution, water, a
mixture of the antifreezing solution and water, and a mixture of
water and an additive having an anticorrosive effect.
9. The air-conditioning apparatus of claim 1, wherein the driving
device comprises a stepping motor.
Description
TECHNICAL FIELD
[0001] The present invention relates to an air-conditioning
apparatus to be applied to, for example, a multi-air-conditioning
apparatus for a building.
BACKGROUND ART
[0002] Hitherto, there exists an air-conditioning apparatus
including a relay unit independently of an outdoor unit and an
indoor unit as an air-conditioning apparatus such as a
multi-air-conditioning apparatus for a building (see, for example,
Patent Literature 1). In the air-conditioning apparatus, heat
source-side refrigerant is circulated between the outdoor unit and
the relay unit to generate heating energy or cooling energy. Then,
a heat medium such as water is circulated between the relay unit
and the indoor unit. A heat exchanger arranged in the relay unit
exchanges heat between the heat source-side refrigerant and the
heat medium to heat or cool the heat medium, which is delivered to
the indoor unit to heat or cool indoors. Further, in Patent
Literature 1, in order to allow a plurality of indoor units to
perform heating or cooling individually, heat medium flow switching
devices for allowing and interrupting a flow of the heat medium to
each of the indoor units are arranged in the relay unit so as to
respectively correspond to the indoor units.
CITATION LIST
Patent Literature
[0003] Patent Literature 1: International Patent WO10/049998A (page
3, FIG. 1, etc.)
SUMMARY OF INVENTION
Technical Problem
[0004] In Patent Literature 1, two heat medium flow switching
devices are required to be arranged for each indoor unit so that a
heating operation or a cooling operation can be individually
selected for each of the indoor units. Therefore, when the number
of connected indoor units increases, a space in which the heat
medium flow switching devices are mounted and driving devices for
driving the heat medium flow switching devices are correspondingly
required. Thus, improvement is required in terms of space saving
and energy saving.
[0005] As the number of heat medium flow switching devices
increases, the probability of need for maintenance including
replacement of the heat medium flow switching devices becomes
higher, leading to reduced ease of maintenance. Therefore, a
smaller number of heat medium flow switching devices is preferred.
However, Patent Literature 1 does not discuss this point at
all.
[0006] The present invention has been made to solve the problem
described above, and has an object to provide an air-conditioning
apparatus capable of saving space and energy, and further,
improving ease of maintenance.
Solution to Problem
[0007] According to one embodiment of the present invention, there
is provided an air-conditioning apparatus, including: a refrigerant
circuit formed by connecting a compressor, a heat source-side heat
exchanger, a plurality of expansion devices, and refrigerant-side
passages in a plurality of intermediate heat exchangers by
refrigerant pipes to allow heat source-side refrigerant to
circulate therethrough; a plurality of heat medium circuits formed
by connecting a plurality of pumps, a plurality of use-side heat
exchangers, and heat medium-side passages in the plurality of
intermediate heat exchangers by heat-medium pipes to allow a heat
medium to circulate therethrough; a plurality of heat medium flow
switching devices, which are provided correspondingly to each of
the plurality of use-side heat exchangers, the plurality of heat
medium flow switching devices to switch a passage for the heat
medium by connecting the use-side heat exchangers to any one of the
plurality of intermediate heat exchangers, the plurality of
use-side heat exchangers being individually connected to any one of
the plurality of intermediate heat exchangers to enable a heating
operation or a cooling operation; and an integrated heat medium
flow switching device formed by entirely or partially integrating
the plurality of heat medium flow switching devices, the integrated
heat medium flow switching device being provided for each of the
plurality of use-side heat exchangers so that the integrated heat
medium flow switching device is driven by a single driving
device.
Advantageous Effects of Invention
[0008] According to the one embodiment of the present invention,
the plurality of heat medium flow switching devices respectively
corresponding to the plurality of use-side heat exchangers are
entirely or partially integrated so that the thus obtained
integrated heat medium flow switching device is driven by the
single driving device. In this manner, driving devices, which are
otherwise required separately for the plurality of heat medium flow
switching devices, may be constructed as the shared common driving
device. Therefore, the number of driving devices may be reduced to
improve energy saving, space saving, and ease of maintenance.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a schematic diagram illustrating an example of
installation of an air-conditioning apparatus 100 according to an
embodiment of the present invention.
[0010] FIG. 2 is a schematic circuit configuration diagram
illustrating an example of a circuit configuration of the
air-conditioning apparatus 100 according to the embodiment of the
present invention.
[0011] FIG. 3 is a refrigerant circuit diagram illustrating a flow
of refrigerant in a heating only operation mode of the
air-conditioning apparatus 100 according to the embodiment of the
present invention.
[0012] FIG. 4 is a refrigerant circuit diagram illustrating the
flow of the refrigerant in a cooling only operation mode of the
air-conditioning apparatus 100.
[0013] FIG. 5 is a refrigerant circuit diagram illustrating the
flow of the refrigerant in a heating main operation mode of the
air-conditioning apparatus 100 according to the embodiment of the
present invention.
[0014] FIG. 6 is a refrigerant circuit diagram illustrating the
flow of the refrigerant in a cooling main operation mode of the
air-conditioning apparatus 100 according to the embodiment of the
present invention.
[0015] FIG. 7 are explanatory diagrams of integrated heat medium
flow switching devices 40 provided in a relay unit 2 illustrated in
FIG. 1.
[0016] FIG. 8 is a conceptual diagram illustrating a configuration
of a valve body 44 illustrated in FIG. 7.
[0017] FIG. 9 are explanatory diagrams of a rotation stop position
of the valve body 44 of the integrated heat medium flow switching
device 40 and a flow of a heat medium in a state in which the
integrated heat medium flow switching device 40 provided in the
relay unit 2 illustrated in FIG. 1 is switched to an intermediate
heat exchanger 25a side.
[0018] FIG. 10 are explanatory diagrams of the rotation stop
position of the valve body 44 of the integrated heat medium flow
switching device 40 and the flow of the heat medium in a state in
which the integrated heat medium flow switching device 40 provided
in the relay unit 2 illustrated in FIG. 1 is switched to an
intermediate heat exchanger 25b side.
[0019] FIG. 11 are explanatory diagrams of the rotation stop
position of the valve body 44 of the integrated heat medium flow
switching device 40 and the flow of the heat medium in a case where
an indoor unit 3 is separated from a heat medium circuit by the
integrated heat medium flow switching device 40 provided in the
relay unit 2 illustrated in FIG. 1.
[0020] FIG. 12 are diagrams illustrating a modified example of the
integrated heat-medium flow switching device according to the
embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0021] Now, an embodiment of the present invention is described
referring to the drawings.
[0022] FIG. 1 is a schematic diagram illustrating an example of
installation of an air-conditioning apparatus 100 according to an
embodiment of the present invention. Referring to FIG. 1, the
example of installation of the air-conditioning apparatus 100 is
described. This air-conditioning apparatus 100 utilizes a
refrigeration cycle (refrigerant circuit A, refrigerant circuit B)
for circulating refrigerant (heat source-side refrigerant, heat
medium), to thereby allow each indoor unit to freely select any one
of a heating operation and a cooling operation. In FIG. 1, the
entire air-conditioning apparatus 100 in which a plurality of
indoor units 3 are connected is schematically illustrated. Note
that, in the drawings referred to below including FIG. 1, the size
relationship between components may be different from the reality
in some cases. Further, in FIG. 1 and the drawings referred to
below, the same or corresponding parts are represented by the same
reference symbols, and the same applies hereinafter. Further, the
forms of the constituent elements described herein are only
examples and the present invention is not limited to the forms thus
described.
[0023] In FIG. 1, the air-conditioning apparatus 100 according to
this embodiment includes an outdoor unit (heat source apparatus) 1,
the plurality of indoor units 3, and one relay unit 2 interposed
between the outdoor unit 1 and the indoor units 3. The relay unit 2
exchanges heat between the heat source-side refrigerant and the
heat medium. The outdoor unit 1 and the relay unit 2 are connected
to each other by refrigerant pipes 4 through which the heat
source-side refrigerant passes. The relay unit 2 and the indoor
units 3 are connected by pipes (heat medium pipes) 5 through which
the heat medium passes. Then, heating energy or cooling energy
generated by the outdoor unit 1 is sent to the indoor units 3
through the relay unit 2.
[0024] The outdoor unit 1 is generally arranged in an outdoor space
6, which is a space outside of a construction 9 such as a building
(for example, on a rooftop), and supplies the heating energy or
cooling energy to the indoor units 3 through the relay unit 2. The
indoor units 3 are arranged at positions at which heating air or
cooling air can be supplied to an indoor space 7 as a space inside
the construction 9 (for example, residential room), and supply the
heating air or the cooling air to the indoor space 7 as an
air-conditioned space. The relay unit 2 is configured so as to be
installed at a position different from the outdoor space 6 and the
indoor space 7 as a casing independent of the outdoor unit 1 and
the indoor units 3. Then, the relay unit 2 transfers the heating
energy or cooling energy supplied from the outdoor unit 1 to the
indoor units 3.
[0025] An operation of the air-conditioning apparatus 100 according
to the embodiment of the present invention is briefly described.
The heat source-side refrigerant is delivered from the outdoor unit
1 to the relay unit 2 through the refrigerant pipes 4. The thus
delivered heat source-side refrigerant exchanges heat with the heat
medium circulating through the heat medium circuit B in
intermediate heat exchangers (described later) included in the
relay unit 2 to heat or cool the heat medium. Specifically, hot
water or cold water is generated by the intermediate heat
exchangers. The hot water or cold water generated by the relay unit
2 is delivered to the indoor unit 3, which is selected by a heat
medium flow switching device (described later), by a heat medium
delivery device (described later) through the heat-medium pipes 5
so as to be used in the indoor unit 3 for a heating operation or a
cooling operation for the indoor space 7.
[0026] As the heat source-side refrigerant, there exist, for
example, a single-component refrigerant such as R-22, R-134a, and
R32, a near-azeotropic refrigerant mixture such as R-410A and
R-404A, a zeotropic refrigerant mixture such as R-407C, and a
refrigerant having a double bond in a chemical formula and having a
relatively small value of a global warming potential such as
CF.sub.3CF.dbd.CH.sub.2. As the heat source-side refrigerant, a
mixture of the above-mentioned refrigerants may be used. Further, a
natural refrigerant such as CO.sub.2 and propane, which can be
turned into a supercritical state, may be used as the heat
source-side refrigerant.
[0027] On the other hand, as the heat medium, for example, brine
(antifreezing solution) or water, a mixture of brine and water, and
a mixture of water and an additive having a high anticorrosive
effect can be used. Therefore, even when the heat medium leaks into
the indoor space 7 through the indoor units 3 in the
air-conditioning apparatus 100, the heat medium contributes to
improvement of safety because of the use of the heat medium having
high safety.
[0028] As illustrated in FIG. 1, in the air-conditioning apparatus
100 according to this embodiment, the outdoor unit 1 and the relay
unit 2 are connected by using the two refrigerant pipes 4. Further,
the relay unit 2 and each of the indoor units 3 are connected by
using the two heat-medium pipes 5. Some of the air-conditioning
apparatus 100, in which each of the indoor units can freely
selectively operate, the heating operation or the cooling operation
(for example, Japanese Unexamined Patent Application Publication
No. Hei 05-280818, etc.) are air-conditioning apparatus in which
the respective units (the outdoor unit 1, the indoor units 3, and
the relay unit 2) are connected by four pipes. In the
air-conditioning apparatus 100 according to this embodiment,
however, the respective units (the outdoor unit 1, the indoor units
3, and the relay unit 2) are connected by two pipes. As a result,
construction work is facilitated as compared with a related-art
case where four pipes are used.
[0029] In FIG. 1, a state in which the relay unit 2 is installed in
a space inside the construction 9, such as a space above a ceiling
being a different space from the indoor space 7 (hereinafter
referred to simply as "space 8"), is illustrated as an example. The
relay unit 2 may also be installed in a shared space where an
elevator is installed. Further, in FIG. 1, a case where the indoor
unit 3 is a ceiling cassette type indoor unit is illustrated as an
example, but the present invention is not limited thereto. Any
types of the indoor unit such as a ceiling-concealed indoor unit or
a ceiling-suspended indoor unit may be adopted. In other words, the
indoor unit 3 may be of any type as long as heating air or cooling
air can be blown into the indoor space 7 directly or through a duct
or the like.
[0030] In FIG. 1, a case where the outdoor unit 1 is installed in
the outdoor space 6 is illustrated as an example, but the present
invention is not limited thereto. For example, the outdoor unit 1
may be installed in an enclosed space such as a machine room with a
ventilation port, or may be installed inside the construction 9 as
long as waste heat is exhaustible to the outside of the
construction 9 through an exhaust duct. Further, even when a
water-cooled outdoor unit 1 is adopted, the outdoor unit 1 may be
installed inside the construction 9. No particular problem may
arise even if the outdoor unit 1 is installed at such a place.
[0031] The relay unit 2 may be installed in the vicinity of the
outdoor unit 1. However, note that, if a distance from the relay
unit 2 to the indoor units 3 is too long, heat-medium delivery
power is significantly increased to result in lowered energy saving
effects. Further, the numbers of connected outdoor units 1, indoor
units 3, and relay units 2 are not limited to those illustrated in
FIG. 1. The numbers only need to be determined based on the
construction 9, in which the air-conditioning apparatus 100
according to this embodiment is installed.
[0032] When a plurality of the relay units 2 are connected to the
single outdoor unit 1, the plurality of relay units 2 can be
installed to be spaced apart from each other in the shared space or
the space above the ceiling in a construction such as a building.
With the installation described above, an air conditioning load can
be treated by the intermediate heat exchanger included in each of
the relay units 2. Further, the indoor units 3 can be installed at
a distance or a height within an allowable delivery range of pumps
31 to be described later in each of the relay units 2. As a result,
the arrangement of the indoor units 3 in the whole construction
such as the building is enabled.
[0033] FIG. 2 is a schematic circuit configuration diagram
illustrating an example of a circuit configuration of the
air-conditioning apparatus 100 according to the embodiment of the
present invention. Referring to FIG. 2, a configuration of the
air-conditioning apparatus 100, specifically, functions of each of
actuators included in a refrigerant circuit are described in
detail. As illustrated in FIG. 2, the outdoor unit 1 and the relay
unit 2 are connected by the refrigerant pipes 4 through an
intermediate heat exchanger (refrigerant-water heat exchanger) 25a
and an intermediate heat exchanger (refrigerant-water heat
exchanger) 25b included in the relay unit 2. Further, the relay
unit 2 and the indoor units 3 are connected by the heat-medium
pipes 5 through the intermediate heat exchanger 25a, the
intermediate heat exchanger 25b, heat medium flow switching devices
32 (32a to 32d), and heat medium flow switching devices 33 (33a to
33d). The details of the refrigerant pipes 4 and the heat-medium
pipes 5 are described later.
[0034] In FIG. 2, the heat medium flow switching devices 32 (32a to
32d) and the heat medium flow switching devices 33 (33a to 33d) are
illustrated as separate devices. However, this illustration is to
illustrate the functions of the refrigerant circuit of the
air-conditioning apparatus 100. In terms of structure, a single
integrated heat medium flow switching device 40 formed by
integrating the heat medium flow switching device 32 (32a to 32d)
and the heat medium flow switching device 33 (33a to 33d) is
mounted.
[0035] The number of integrated heat medium flow switching devices
40 provided corresponds to the number of installed indoor units 3.
In this case, the number of provided indoor units 3 is four, and
hence four integrated heat medium flow switching devices 40 are
mounted. In FIG. 2, an integrated heat medium flow switching device
40a, an integrated heat medium flow switching device 40b, an
integrated heat medium flow switching device 40c, and an integrated
heat medium flow switching device 40d are illustrated in the stated
order from an upper side on the drawing sheet so as to correspond
to the indoor units 3. This embodiment has a feature in the
integrated heat medium flow switching devices 40. The details of
the integrated heat medium flow switching devices 40 are
specifically described later.
[Outdoor Unit 1]
[0036] In the outdoor unit 1, a compressor 10, a first refrigerant
flow switching device 11 such as a four-way valve, a heat
source-side heat exchanger 12, and an accumulator 19 are mounted by
a serial connection by the refrigerant pipes 4. Further, the
outdoor unit 1 includes a refrigerant-use connection pipe 4a, a
refrigerant-use connection pipe 4b, a check valve 13a, a check
valve 13b, a check valve 13c, and a check valve 13d. By providing
the refrigerant-use connection pipe 4a, the refrigerant-use
connection pipe 4b, the check valve 13a, the check valve 13b, the
check valve 13c, and the check valve 13d, a flow of the heat
medium-side refrigerant into the relay unit 2 can be directed in a
constant direction regardless of whether an operation required for
the indoor units 3 is heating or cooling.
[0037] The compressor 10 sucks the heat source-side refrigerant,
and compresses the heat source-side refrigerant into a
high-temperature and high-pressure state to deliver the heat
source-side refrigerant to the refrigerant circuit A. The
compressor 10 only needs to be a capacity-controllable inverter
compressor or the like, for example. The first refrigerant flow
switching device 11 performs switching between a flow of the heat
source-side refrigerant during a heating operation (in a heating
only operation mode and a heating main operation mode to be
described later) and a flow of the heat source-side refrigerant
during a cooling operation (in a cooling only operation mode and a
cooling main operation mode to be described later).
[0038] The heat source-side heat exchanger 12 functions as an
evaporator during the heating operation and functions as a
condenser (or a radiator) during the cooling operation. The heat
source-side heat exchanger 12 exchanges heat between a fluid of air
supplied from an air-sending device such as a fan (not shown) and
the heat source-side refrigerant, and evaporates and gasifies or
condenses and liquefies the heat source-side refrigerant. The
accumulator 19 is arranged on a suction side of the compressor 10,
and accumulates therein surplus refrigerant generated due to a
difference between the heating operation and the cooling operation
or surplus refrigerant due to a transient change in operation.
[0039] The check valve 13c is provided to the refrigerant pipe 4
between the relay unit 2 and the first refrigerant flow switching
device 11, and allows the flow of the heat source-side refrigerant
only in a predetermined direction (direction from the relay unit 2
to the outdoor unit 1). The check valve 13a is provided to the
refrigerant pipe 4 between the heat source-side heat exchanger 12
and the relay unit 2, and allows the flow of the heat source-side
refrigerant only in a predetermined direction (direction from the
outdoor unit 1 to the relay unit 2). The check valve 13d is
provided to the refrigerant-use connection pipe 4a, and controls
the heat source-side refrigerant discharged from the compressor 10
to flow through the relay unit 2 during the heating operation. The
check valve 13b is provided to the refrigerant-use connection pipe
4b, and controls the heat source-side refrigerant returned from the
relay unit 2 to flow to the suction side of the compressor 10
during the heating operation.
[0040] The refrigerant-use connection pipe 4a connects the
refrigerant pipe 4 between the first refrigerant flow switching
device 11 and the check valve 13c and the refrigerant pipe 4
between the check valve 13a and the relay unit 2 in the outdoor
unit 1. The refrigerant-use connection pipe 4b connects the
refrigerant pipe 4 between the check valve 13c and the relay unit 2
and the refrigerant pipe 4 between the heat source-side heat
exchanger 12 and the check valve 13a in the outdoor unit 1. In FIG.
2, a case where the refrigerant-use connection pipe 4a, the
refrigerant-use connection pipe 4b, the check valve 13a, the check
valve 13b, the check valve 13c, and the check valve 13d are
provided is illustrated as an example. However, the configuration
is not limited thereto. The above-mentioned components are not
necessarily required to be provided.
[Indoor Units 3]
[0041] In each of the indoor units 3, a use-side heat exchanger 35
is mounted. The use-side heat exchanger 35 is connected to the heat
medium flow switching device 32 and the heat medium flow switching
device 33 included in the relay unit 2 by the heat-medium pipes 5.
The use-side heat exchanger 35 exchanges heat between the air
supplied from the air-sending device such as the fan (not shown)
and the heat medium to generate heating air or cooling air to be
supplied to the indoor space 7.
[0042] In FIG. 2, a case where the four indoor units 3 are
connected to the relay unit 2 is illustrated as an example, and the
indoor units are illustrated as an indoor unit 3a, an indoor unit
3b, an indoor unit 3c, and an indoor unit 3d in the stated order
from the upper side on the drawing sheet. Correspondingly to the
indoor units 3a to 3d, the use-side heat exchangers 35 are
illustrated as a use-side heat exchanger 35a, a use-side heat
exchanger 35b, a use-side heat exchanger 35c, and a use-side heat
exchanger 35d in the stated order from the upper side on the
drawing sheet. Similarly to FIG. 1, the number of indoor units 3 to
be connected is not limited to four as illustrated in FIG. 2.
[Relay Unit 2]
[0043] In the relay unit 2, two or more intermediate heat
exchangers 25 (two, that is, the intermediate heat exchanger 25a
and the intermediate heat exchanger 25b in this case), two
expansion devices 26 (26a, 26b), two opening and closing devices
(an opening and closing device 27 and an opening and closing device
29), two second refrigerant flow switching devices 28 (28a, 28b),
pumps 31 (31a, 31b) that are two heat medium delivery devices
(hereinafter referred to as "pumps"), and the four integrated heat
medium flow switching devices 40 (40a to 40d) are mounted.
[0044] The two intermediate heat exchangers 25 (the intermediate
heat exchanger 25a and the intermediate heat exchanger 25b)
function as the condensers (radiators) when the heating energy is
supplied to the indoor units 3 performing the heating operation.
The two intermediate heat exchangers 25 (the intermediate heat
exchanger 25a and the intermediate heat exchanger 25b) function as
the evaporators when the cooling energy is supplied to the indoor
units 3 performing the cooling operation. The two intermediate heat
exchangers 25 exchange heat between the heat source-side
refrigerant and the heat medium to transfer the heating energy or
the cooling energy stored in the heat source-side refrigerant,
which is generated in the outdoor unit 1, to the heat medium.
[0045] The intermediate heat exchanger 25a is arranged between the
expansion device 26a and the second refrigerant flow switching
device 28a in the refrigerant circuit A and serves to cool the heat
medium in the cooling and heating mixed operation mode. Further,
the intermediate heat exchanger 25b is arranged between the
expansion device 26b and the second refrigerant flow switching
device 28b in the refrigerant circuit A and serves to heat the heat
medium in the cooling and heating mixed operation mode.
[0046] The two expansion devices 26 (the expansion device 26a and
the expansion device 26b) function as pressure reducing valves or
expansion valves, and decompress the heat source-side refrigerant
to expand the heat source-side refrigerant. The expansion device
26a is arranged on an upstream side of the intermediate heat
exchanger 25a in the flow of the heat source-side refrigerant
during the cooling only operation. The expansion device 26b is
arranged on an upstream side of the intermediate heat exchanger 25b
in the flow of the heat source-side refrigerant during the cooling
only operation. The two expansion devices 26 only need to be
devices capable of variably controlling their opening degrees, such
as electronic expansion valves.
[0047] The two opening and closing devices (the opening and closing
device 27 and the opening and closing device 29) are each
constructed of a solenoid valve capable of performing an opening
and closing operation by energization, and open and close the
refrigerant pipes 4. Specifically, the two opening and closing
devices (the opening and closing device 27 and the opening and
closing device 29) are controlled to be opened and closed based on
the operation mode to switch a passage for the heat source-side
refrigerant. The opening and closing device 27 is provided to the
refrigerant pipe 4 (refrigerant pipe 4 located in the lowermost
column on the drawing sheet of FIG. 2 among the refrigerant pipes 4
that connect the outdoor unit 1 and the relay unit 2), which is
arranged on an inlet side for the heat source-side refrigerant. The
opening and closing device 29 is provided to a pipe (bypass pipe
20) that connects the refrigerant pipe 4 on the inlet side for the
heat source-side refrigerant and the refrigerant pipe 4 on an
outlet side for the heat source-side refrigerant. The opening and
closing device 27 and the opening and closing device 29 only need
to be capable of switching the passage for the refrigerant. For
example, electronic expansion valves capable of variably
controlling their opening degrees may be used.
[0048] The two second refrigerant flow switching devices 28 (the
second refrigerant flow switching device 28a and the second
refrigerant flow switching device 28b) are constructed of, for
example, four-way valves or the like, and switch the flow of the
heat source-side refrigerant so that the intermediate heat
exchangers 25 function as the condensers or the evaporators based
on the operation mode. The second refrigerant flow switching device
28a is arranged on a downstream side of the intermediate heat
exchanger 25a in the flow of the heat source-side refrigerant in
the cooling only operation mode. The second refrigerant flow
switching device 28b is arranged on a downstream side of the
intermediate heat exchanger 25b in the flow of the heat source-side
refrigerant in the cooling only operation mode.
[0049] The two pumps 31 (the pump 31a and the pump 31b) circulate
the heat medium passing through the heat medium pipes 5 through the
heat medium circuit B. The pump 31a is provided to the heat medium
pipe 5 between the intermediate heat exchanger 25a and the
integrated heat medium flow switching devices 40. The pump 31b is
provided to the heat medium pipe 5 between the intermediate heat
exchanger 25b and the integrated heat medium flow switching devices
40. The two pumps 31 only need to be, for example,
capacity-controllable pumps so that a flow rate can be controlled
based on the magnitude of loads in the indoor units 3.
[0050] The integrated heat medium flow switching devices 40 are
arranged so as to respectively correspond to the indoor units 3 as
described above and have a function of switching a destination of
connection of the corresponding use-side heat exchanger 35 to the
intermediate heat exchanger 25a or the intermediate heat exchanger
25b. Specifically, each of the integrated heat medium flow
switching devices 40 opens an internal passage so that the passage
for the heat medium is switched to the intermediate heat exchanger
25a side or the intermediate heat exchanger 25b side. The switching
of the heat medium passages includes not only perfect switching
from one to the other but also partial switching from one to the
other.
[0051] Further, the integrated heat medium flow switching devices
40 also have a function of controlling an opening area of the
passage to control the flow rate of the heat medium flowing through
the heat medium pipes 5, thereby controlling the flow rate of the
heat medium into the indoor units 3. The integrated heat medium
flow switching devices 40 control the amount of heat medium flowing
into the indoor units 3 based on a temperature of the heat medium
flowing into the indoor units 3 and a temperature of the heat
medium flowing out of the indoor units 3, thereby being capable of
providing an optimal amount of heat medium suitable for an air
conditioning load for the indoor space 7 to the indoor units 3.
[0052] When optimal control based on the optimal flow rate of the
heat medium corresponding to the load is not required in the
connected indoor units 3, the integrated heat medium flow switching
devices 40 are not necessarily required to have the flow rate
controlling function. Therefore, the integrated heat medium flow
switching devices 40 only need to have at least the flow switching
function. In the following description, however, the integrated
heat medium flow switching devices 40 are described as having both
the flow switching function and the flow rate controlling
function.
[0053] When a load such as stop or thermostat-off is not required
or the passage for the heat medium is desired to be interrupted for
maintenance or the like in the indoor unit 3, the integrated heat
medium flow switching device 40 can be fully closed to stop the
supply of the heat medium to the indoor unit 3. Specifically, each
of the integrated heat medium flow switching devices 40 also has a
function of interrupting the internal passage to separate the
corresponding use-side heat exchanger 35 from the heat medium
circuit B.
[0054] The relay unit 2 further includes temperature sensors 55 (a
temperature sensor 55a and a temperature sensor 55b) for detecting
a temperature of the heat medium on an outlet side of the
intermediate heat exchangers 25. Information detected by the
temperature sensors 55 (temperature information) is sent to a
controller 50 for collectively controlling the operation of the
air-conditioning apparatus 100.
[0055] The controller 50 is a microcomputer or the like, and
controls the entire air-conditioning apparatus 100 based on
information detected by various detection units and a command from
a remote controller. Specifically, the controller 50 controls
driving frequency of the compressor 10, a rotation speed (including
ON/OFF) of the air-sending device (not shown), switching of the
first refrigerant flow switching device 11, driving frequency of
the pumps 31, switching of the second refrigerant flow switching
devices 28, an opening degree of the expansion devices 26, opening
and closing of the opening and closing devices 27 and 29, control
of driving devices 41 for the integrated heat medium flow switching
devices 40 (switching of the passage for the heat medium and
control of the heat medium flow rate in the indoor units 3), and
the like. Further, the controller 50 executes each of the operation
modes to be described later.
[0056] In FIG. 2, a configuration, in which the controller 50 is
installed separately from the outdoor unit 1, the indoor units 3,
and the relay unit 2 so as to be communicable to/from the units
described above, is illustrated. However, the configuration is not
limited thereto. For example, the controller 50 may be mounted in
any one of the outdoor unit 1, the indoor units 3, and the relay
unit 2, or the functions of the controller 50 may be provided to
the outdoor unit 1, the indoor units 3, and the relay unit 2 in a
distributed manner to perform cooperation processing through data
communication.
[0057] The heat medium pipes 5 for allowing the heat medium to pass
therethrough include those to be connected to the intermediate heat
exchanger 25a and those to be connected to the intermediate heat
exchanger 25b. The heat medium pipes 5 are split based on the
number of indoor units 3 to be connected to the relay unit 2 (each
being split into four in this case). The heat medium pipes 5 are
connected to the integrated heat medium flow switching devices 40.
By controlling the integrated heat medium flow switching devices
40, the heat medium can be switched to the flow from the
intermediate heat exchanger 25a into the use-side heat exchangers
35 or the flow from the intermediate heat exchanger 25b into the
use-side heat exchangers 35.
[0058] Then, in the air-conditioning apparatus 100, the compressor
10, the first refrigerant flow switching device 11, the heat
source-side heat exchanger 12, the opening and closing device 27,
the opening and closing device 29, the second refrigerant flow
switching devices 28, the refrigerant passages in the intermediate
heat exchangers 25, the expansion devices 26, and the accumulator
19 are connected by the refrigerant pipes 4 to form the refrigerant
circuit A. Further, the heat medium passages in the intermediate
heat exchangers 25, the pumps 31, the integrated heat medium flow
switching devices 40, and the use-side heat exchangers 35 are
connected by the heat medium pipes 5 to form the heat medium
circuit B. Specifically, the plurality of use-side heat exchangers
35 are connected to each of the intermediate heat exchangers 25 in
parallel to form the heat medium circuit B as a plurality of
systems.
[0059] Thus, in the air-conditioning apparatus 100, the heat
source-side refrigerant circulating through the refrigerant circuit
A and the heat medium circulating through the heat medium circuit B
exchange heat in the intermediate heat exchanger 25a and the
intermediate heat exchanger 25b. By using the configuration
described above, the air-conditioning apparatus 100 can realize an
optimal heating operation or cooling operation suitable for the air
conditioning load.
[Operation Mode]
[0060] Each of the operation modes to be executed by the
air-conditioning apparatus 100 is described. Based on an
instruction from each of the indoor units 3, the air-conditioning
apparatus 100 enables the indoor units 3 to perform the heating
operation or the cooling operation. Specifically, the
air-conditioning apparatus 100 enables all the indoor units 3 to
perform the same operation and also enables each of the indoor
units 3 to perform a different operation.
[0061] There are the following four operation modes to be executed
by the air-conditioning apparatus 100. Now, each of the operation
modes is described with the flows of the heat source-side
refrigerant and the heat medium.
[0062] 1. Heating only operation mode (mode in which all the driven
indoor units 3 perform the heating operation)
[0063] 2. Cooling only operation mode (mode in which all the driven
indoor units 3 perform the cooling operation)
[0064] 3. Heating main operation mode (cooling and heating mixed
operation mode in which a heating load is larger than a cooling
load)
[0065] 4. Cooling main operation mode (cooling and heating mixed
operation mode in which a cooling load is larger than a heating
load)
[Heating Only Operation Mode]
[0066] FIG. 3 is a refrigerant circuit diagram illustrating the
flow of the refrigerant in the heating only operation mode of the
air-conditioning apparatus 100 according to the embodiment of the
present invention. In FIG. 3, the heating only operation mode is
described taking as an example a case where all the use-side heat
exchangers 35a to 35d perform the heating operation and a heating
load is generated in all the use-side heat exchangers 35a to 35d.
In FIG. 3, the pipes indicated by the thick lines are the pipes
through which the heat source-side refrigerant flows. Further, in
FIG. 3, the direction of the flow of the heat source-side
refrigerant is indicated by the solid arrows, whereas the direction
of the flow of the heat medium is indicated by the dashed
arrows.
[0067] In the case of the heating only operation mode illustrated
in FIG. 3, in the outdoor unit 1, the first refrigerant flow
switching device 11 is switched so that the heat source-side
refrigerant discharged from the compressor 10 flows into the relay
unit 2 without passing through the heat source-side heat exchanger
12. In the relay unit 2, the pumps 31a and 31b are driven to open
the heat medium flow switching devices 32a and 32d. The heat medium
is circulated between each of the intermediate heat exchanger 25a
and the intermediate heat exchanger 25b and the use-side heat
exchangers 35a to 35d by opening the integrated heat medium flow
switching devices 40a to 40d. Further, the second refrigerant flow
switching device 28a and the second refrigerant flow switching
device 28b are switched to a heating side (solid-line side in FIG.
2). As a result, the opening and closing device 27 is closed,
whereas the opening and closing device 29 is opened.
[0068] First, the flow of the heat source-side refrigerant in the
refrigerant circuit A is described.
[0069] Low-temperature and low-pressure refrigerant is compressed
by the compressor 10 and discharged from the compressor 10 as
high-temperature and high-pressure gas refrigerant. The
high-temperature and high-pressure gas refrigerant discharged from
the compressor 10 passes through the first refrigerant flow
switching device 11 and then through the refrigerant-use connection
pipe 4a and the check valve 13d to flow out of the outdoor unit 1.
The high-temperature and high-pressure gas refrigerant flowing out
of the outdoor unit 1 passes through the refrigerant pipe 4 to flow
into the relay unit 2.
[0070] The high-temperature and high-pressure gas refrigerant
flowing into the relay unit 2 is split and respectively passes
through the second refrigerant flow switching device 28a and the
second refrigerant flow switching device 28b. Then, the
high-temperature and high-pressure gas refrigerant flows into the
intermediate heat exchanger 25a and the intermediate heat exchanger
25b. The high-temperature and high-pressure gas refrigerant flowing
into the intermediate heat exchanger 25a and the intermediate heat
exchanger 25b is condensed and liquefied while rejecting heat to
the heat medium circulating through the heat medium circuit B, and
turns into high-pressure liquid refrigerant. The high-pressure
liquid refrigerant flows out of the intermediate heat exchanger 25a
and the intermediate heat exchanger 25b.
[0071] The liquid refrigerant flowing out of the intermediate heat
exchanger 25a and the intermediate heat exchanger 25b is expanded
by the expansion device 26a and the expansion device 26b to turn
into low-temperature and low-pressure two-phase refrigerants. The
two-phase refrigerants join together and then pass through the
opening and closing device 29 to flow out of the relay unit 2.
Then, the refrigerant flows into the outdoor unit 1 again through
the refrigerant pipe 4. The refrigerant flowing into the outdoor
unit 1 passes through the refrigerant-use connection pipe 4b and
the check valve 13b to flow into the heat source-side heat
exchanger 12 functioning as the evaporator.
[0072] Then, the heat source-side refrigerant flowing into the heat
source-side heat exchanger 12 removes heat from the air in the
outdoor space 6 (hereinafter referred to as "outside air") by the
heat source-side heat exchanger 12 to turn into low-temperature and
low-pressure gas refrigerant. The low-temperature and low-pressure
gas refrigerant flowing out of the heat source-side heat exchanger
12 is sucked into the compressor 10 again through the first
refrigerant flow switching device 11 and the accumulator 19.
[0073] At this time, the opening degree of the expansion device 26
is controlled by the controller 50 so that subcool (degree of
subcooling) determined as a difference between a value determined
by converting the pressure of the heat source-side refrigerant
flowing between the intermediate heat exchanger 25 and the
expansion device 26 into a saturation temperature and the
temperature on the outlet side of the intermediate heat exchanger
25 becomes constant. Note that, when a temperature at an
intermediate position in the intermediate heat exchangers 25 can be
measured, the temperature at the intermediate position may be used
in place of the converted saturation temperature. In this case, a
pressure sensor is not required to be installed, and the system can
be constructed at low cost.
[0074] Next, the flow of the heat medium in the heat medium circuit
B is described. In the heating only operation mode, the heating
energy of the heat source-side refrigerant is transferred to the
heat medium in both the intermediate heat exchanger 25a and the
intermediate heat exchanger 25b. The heated heat medium is
controlled to flow through the heat medium pipe 5 by the pump 31a
and the pump 31b. The heat medium, which is pressurized by the pump
31a and the pump 31b, flows into the use-side heat exchangers 35a
to 35d after the passage for the heat medium is switched by the
integrated heat medium flow switching devices 40. At this time, it
is desired to switch the passage so that a total heating capacity
of the indoor units 3 in which the heating is performed by the heat
medium passing through the intermediate heat exchanger 25a side and
a total heating capacity of the indoor units 3 in which the heating
is performed by the heat medium passing through the intermediate
heat exchanger 25b side are approximately halved.
[0075] A capacity of heating by each of the indoor units 3 can be
determined by, for example, the controller 50. Based on the heating
capacity, the passage in the integrated heat medium flow switching
device 40 is switched. In this case, each of the integrated heat
medium flow switching devices 40 is switched so that, for example,
the heat medium passing through the intermediate heat exchanger 25a
side flows into the use-side heat exchangers 35c and 35d while the
heat medium passing through the intermediate heat exchanger 25b
side flows into the use-side heat exchangers 35a and 35b.
[0076] The heat medium flowing into the use-side heat exchangers
35a to 35d rejects heat to indoor air to heat the indoor space
7.
[0077] The heat medium then flows out of the use-side heat
exchangers 35a to 35d to flow into the integrated heat medium flow
switching devices 40a to 40d again. At this time, the integrated
heat medium flow switching devices 40 are controlled so that the
flow rate of the heat medium becomes a flow rate necessary to cover
the air conditioning load that is required indoors. By the
flow-rate controlling action in the integrated heat medium flow
switching devices 40a to 40d, the controlled flow rate of the heat
medium flows into the use-side heat exchangers 35a to 35d.
[0078] The heat medium flowing out of each of the integrated heat
medium flow switching devices 40a to 40d flows into the
intermediate heat exchanger 25a or the intermediate heat exchanger
25b to receive, from the refrigerant side, the amount of heat equal
to the amount of heat rejected to the indoor space 7 through the
indoor units 3, and is sucked into the pump 31a or the pump 31b
again.
[0079] The integrated heat medium flow switching devices 40 control
the flow rate of the heat medium flowing into the use-side heat
exchangers 35 as described above. The integrated heat medium flow
switching devices 40 are specifically controlled as follows.
Specifically, the opening degree of the integrated heat medium flow
switching device 40 is controlled so that a temperature difference
between the temperature detected by the temperature sensor 55a or
the temperature detected by the temperature sensor 55b and a
temperature of the heat medium flowing out of the use-side heat
exchanger 35 is kept to a target value. More specifically, when the
temperature difference is larger than the target value, the
integrated heat medium flow switching device 40 is controlled so
that an opening area of the passage is narrowed. When the
temperature difference is smaller than the target value, the
integrated heat medium flow switching device 40 is controlled so
that the opening area of the passage is enlarged.
[0080] By controlling the integrated heat medium flow switching
devices 40 as described above, an optimal heat medium flow rate
suitable for the air conditioning load for the indoor space 7 is
enabled to flow into the use-side heat exchangers 35 so that the
air conditioning load can be appropriately treated. As the outlet
temperature of the intermediate heat exchanger 25, any of the
temperatures obtained by the temperature sensor 55a and the
temperature sensor 55b may be used, or an average temperature
thereof may be used.
[0081] Meanwhile, the opening degree of the integrated heat medium
flow switching devices 40 should be controlled based not on the
temperature difference between the temperature detected by the
temperature sensor 55a or 55b and the temperature of the heat
medium flowing out of the use-side heat exchangers 35 but on a
temperature difference between a temperature at an inlet and a
temperature at an outlet of the use-side heat exchangers 35.
However, the heat medium temperature on the inlet side of the
use-side heat exchangers 35 is substantially the same temperature
as the temperature detected by the temperature sensors 55.
Therefore, the temperature on the inlet side of the use-side heat
exchangers 35 can be substituted by the temperature detected by the
temperature sensor 55 at the outlet of the intermediate heat
exchanger 25 to which the use-side heat exchanger 35 is connected.
By substituting the temperature detected by the temperature sensor
55 for the temperature on the inlet side of the use-side heat
exchanger 35, the temperature sensors are not required to be
arranged on the inlet side of the use-side heat exchangers 35.
Thus, the number of temperature sensors can be reduced, and the
system can be constructed at low cost.
[0082] The opening degree of the integrated heat medium flow
switching devices 40 is controlled based on the temperature
difference described above, but the opening degree of the
integrated heat medium flow switching devices 40 may also be
controlled based on the heat medium temperature at the outlet of
the intermediate heat exchangers 25. In this case, the opening
degree of the integrated heat medium flow switching devices 40 only
needs to be controlled so that the heat medium temperature at the
outlet of the intermediate heat exchangers 25 is kept to the target
value.
[0083] When the heating only operation mode is executed, the heat
medium is not required to be controlled to flow to the use-side
heat exchangers 35 without a heating load (including a
thermostat-off state). Therefore, the passages are closed by the
integrated heat medium flow control devices 40 so that the heat
medium does not flow to the use-side heat exchangers 35. In the
above-mentioned example, the heat medium is controlled to flow
through all the use-side heat exchangers 35a to 35d because of the
presence of heating loads. When the heating load is no longer
present, the corresponding integrated heat medium flow switching
device 40 only needs to be fully closed. When the heating load is
generated again, the corresponding integrated heat medium flow
switching device 40 only needs to be opened to circulate the heat
medium. This applies to the other operation modes to be described
below.
[Cooling Only Operation Mode]
[0084] FIG. 4 is a refrigerant circuit diagram illustrating the
flow of the refrigerant in the cooling only operation mode of the
air-conditioning apparatus 100. Referring to FIG. 4, the cooling
only operation mode is described taking as an example a case where
all the use-side heat exchangers 35a to 35d perform the cooling
operation and a cooling load is generated in all the use-side heat
exchangers 35a to 35d. In FIG. 4, the direction of the flow of the
heat source-side refrigerant is indicated by the solid arrows,
whereas the direction of the flow of the heat medium is indicated
by the dashed arrows.
[0085] In the case of the cooling only operation mode illustrated
in FIG. 4, in the outdoor unit 1, the first refrigerant flow
switching device 11 is switched so that the heat source-side
refrigerant discharged from the compressor 10 flows into the heat
source-side heat exchanger 12.
[0086] In the relay unit 2, the pump 31a and the pump 31b are
driven to open the integrated heat medium flow switching devices
40. By opening the integrated heat medium flow switching devices
40, the heat medium is allowed to circulate between each of the
intermediate heat exchanger 25a and the intermediate heat exchanger
25b and the use-side heat exchangers 35a to 35d. At this time, the
integrated heat medium flow switching devices 40 are switched to
the cooling side (dotted-line side in FIG. 2). The opening and
closing device 27 is opened, whereas the opening and closing device
29 is closed.
[0087] First, the flow of the heat source-side refrigerant in the
refrigerant circuit A is described.
[0088] Low-temperature and low-pressure refrigerant is compressed
by the compressor 10 and discharged from the compressor 10 as
high-temperature and high-pressure gas refrigerant. The
high-temperature and high-pressure gas refrigerant discharged from
the compressor 10 passes through the first refrigerant flow
switching device 11 to flow into the heat source-side heat
exchanger 12. The refrigerant flowing into the heat source-side
heat exchanger 12 exchanges heat with the outside air to turn into
high-temperature and high-pressure liquid or two-phase refrigerant,
which then flows out of the heat source-side heat exchanger 12.
After passing through the check valve 13a, the refrigerant flowing
out of the heat source-side heat exchanger 12 flows out of the
outdoor unit 1. The high-temperature and high-pressure liquid or
two-phase refrigerant flowing out of the outdoor unit 1 passes
through the refrigerant pipes 4 to flow into the relay unit 2.
[0089] The high-temperature and high-pressure liquid or two-phase
refrigerant flowing into the relay unit 2 passes through the
opening and closing device 27, and is then split and expanded by
the expansion devices 26a and 26b to turn into low-temperature and
low-pressure two-phase refrigerants. The two-phase refrigerants
evaporate and gasify while removing heat from the heat medium
circulating through the heat medium circuit B to turn into
low-temperature gas refrigerants. The gas refrigerants flowing out
of the intermediate heat exchangers 25a and 25b pass through the
second refrigerant flow switching device 28a and the second
refrigerant flow switching device 28b, and then join together and
flow out of the relay unit 2. The refrigerant flowing out of the
relay unit 2 passes through the refrigerant pipes 4 and the check
valve 13c to be sucked into the compressor 10 again through the
first refrigerant flow switching device 11 and the accumulator
19.
[0090] At this time, the opening degree of the expansion device 26
is controlled so that superheat (degree of superheat) determined as
a difference between a value determined by converting the pressure
of the heat source-side refrigerant flowing between the
intermediate heat exchanger 25 and the expansion device 26 into a
saturation temperature and the temperature on the outlet side of
the intermediate heat exchanger 25 becomes constant. Note that,
when a temperature at an intermediate position in the intermediate
heat exchangers 25 can be measured, the temperature at the
intermediate position may be used in place of the converted
saturation temperature. In this case, a pressure sensor is not
required to be installed, and the system can be constructed at low
cost.
[0091] Next, the flow of the heat medium in the heat medium circuit
B is described.
[0092] In the cooling only operation mode, the cooling energy of
the heat medium is transferred to the heat source-side refrigerant
in both the intermediate heat exchanger 25a and the intermediate
heat exchanger 25b. The cooled heat medium is controlled to flow
through the heat medium pipe 5 by the pump 31a and the pump 31b.
The heat medium, which is pressurized by the pump 31a and the pump
31b, flows into the use-side heat exchangers 35a to 35d after the
passage for the heat medium is switched by the integrated heat
medium flow switching devices 40. At this time, it is desired to
switch the passage so that a total cooling capacity of the indoor
units 3 in which the cooling is performed by the heat medium
passing through the intermediate heat exchanger 25a side and a
total cooling capacity of the indoor units 3 in which the cooling
is performed by the heat medium passing through the intermediate
heat exchanger 25b side are approximately halved.
[0093] A capacity of cooling by each of the indoor units 3 can be
determined by, for example, the controller 50. Based on the cooling
capacity, the passage in the integrated heat medium flow switching
device 40 is switched. In this case, each of the integrated heat
medium flow switching devices 40 is switched so that, for example,
the heat medium passing through the intermediate heat exchanger 25a
side flows into the use-side heat exchangers 35c and 35d while the
heat medium passing through the intermediate heat exchanger 25b
side flows into the use-side heat exchangers 35a and 35b.
[0094] The heat medium flowing into the use-side heat exchangers
35a to 35d removes heat from indoor air to cool the indoor space
7.
[0095] The heat medium then flows out of the use-side heat
exchangers 35a to 35d to flow into the integrated heat medium flow
switching devices 40a to 40d again. At this time, the integrated
heat medium flow switching devices 40 to 40d are controlled so that
the flow rate of the heat medium becomes a flow rate necessary to
cover the air conditioning load for the indoor space 7. By the
flow-rate controlling action in the integrated heat medium flow
switching devices 40a to 40d, the controlled flow rate of the heat
medium flows into the use-side heat exchangers 35a to 35d.
[0096] The heat medium flowing out of each of the integrated heat
medium flow switching devices 40a to 40d flows into the
intermediate heat exchanger 25a or the intermediate heat exchanger
25b to transfer, to the refrigerant side, the amount of heat equal
to the amount of heat removed from the indoor space 7 through the
indoor units 3, and is sucked into the pump 31a or the pump 31b
again.
[0097] The integrated heat medium flow switching devices 40 control
the flow rate of the heat medium flowing into the use-side heat
exchangers 35 as described above. The integrated heat medium flow
switching devices 40 are specifically controlled as follows.
Specifically, the opening degree of the integrated heat medium flow
switching device 40 is controlled so that a temperature difference
between the temperature detected by the temperature sensor 55a or
the temperature detected by the temperature sensor 55b and a
temperature of the heat medium flowing out of the use-side heat
exchanger 35 is kept to a target value. More specifically, when the
temperature difference is larger than the target value, the
integrated heat medium flow switching device 40 is controlled so
that an opening area of the passage is narrowed. When the
temperature difference is smaller than the target value, the
integrated heat medium flow switching device 40 is controlled so
that the opening area of the passage is enlarged.
[0098] By controlling the integrated heat medium flow switching
devices 40 as described above, an optimal heat medium flow rate
suitable for the air conditioning load for the indoor space 7 is
enabled to flow into the use-side heat exchangers 35 so that the
air conditioning load can be appropriately treated. As the outlet
temperature of the intermediate heat exchanger 25, any of the
temperatures obtained by the temperature sensor 55a and the
temperature sensor 55b may be used, or an average temperature
thereof may be used.
[0099] Meanwhile, the opening degree of the integrated heat medium
flow switching devices 40 should be controlled based not on the
temperature difference between the temperature detected by the
temperature sensor 55a or 55b and the temperature of the heat
medium flowing out of the use-side heat exchangers 35 but on a
temperature difference between a temperature at an inlet and a
temperature at an outlet of the use-side heat exchangers 35.
However, the heat medium temperature on the inlet side of the
use-side heat exchangers 35 is substantially the same temperature
as the temperature detected by the temperature sensors 55.
Therefore, the temperature on the inlet side of the use-side heat
exchangers 35 can be substituted by the temperature detected by the
temperature sensor 55 at the outlet of the intermediate heat
exchanger 25 to which the use-side heat exchanger 35 is connected.
By substituting the temperature detected by the temperature sensor
55 for the temperature on the inlet side of the use-side heat
exchanger 35, the temperature sensors are not required to be
arranged on the inlet side of the use-side heat exchangers 35.
Thus, the number of temperature sensors can be reduced, and the
system can be constructed at low cost.
[0100] The opening degree of the integrated heat medium flow
switching devices 40 is controlled based on the temperature
difference described above, but the opening degree of the
integrated heat medium flow switching devices 40 may also be
controlled based on the heat medium temperature at the outlet of
the intermediate heat exchangers 25. In this case, the opening
degree of the integrated heat medium flow switching devices 40 only
needs to be controlled so that the heat medium temperature at the
outlet of the intermediate heat exchangers 25 is kept to the target
value.
[Mixed Operation Mode: Heating Main Operation]
[0101] Now, the heating main operation mode of a mixed operation,
in which the heating load is generated in any of the use-side heat
exchangers 35 and the cooling load is generated in the remaining
use-side heat exchangers 35, is described.
[0102] FIG. 5 is a refrigerant circuit diagram illustrating the
flow of the refrigerant in the heating main operation mode of the
air-conditioning apparatus 100 according to the embodiment of the
present invention. The pipes indicated by the thick lines are the
pipes through which the heat source-side refrigerant circulates. In
FIG. 5, the direction of the flow of the heat source-side
refrigerant is indicated by the solid arrows, whereas the direction
of the flow of the heat medium is indicated by the dashed
arrows.
[0103] The outline of differences between the heating main
operation and the heating only operation is now first described.
The expansion device 26a and the expansion device 26b are both
controlled to function as expansion valves during the heating only
operation, but one of the expansion devices 26a and 26b is fully
opened and the other thereof is controlled to function as the
expansion valve during the heating main operation. In this manner,
both the intermediate heat exchanger 25a and the intermediate heat
exchanger 25b function as the condensers during the heating only
operation, whereas the intermediate heat exchanger 25b functions as
the condenser and the intermediate heat exchanger 25a functions as
the evaporator during the heating main operation.
[0104] In the case of the heating main operation mode illustrated
in FIG. 5, in the outdoor unit 1, the first refrigerant flow
switching device 11 is switched so that the heat source-side
refrigerant discharged from the compressor 10 flows into the relay
unit 2 without passing through the heat source-side heat exchanger
12. In the relay unit 2, the pump 31a and the pump 31b are driven
to open the integrated heat medium flow switching devices 40a to
40d. By opening the integrated heat medium flow switching devices
40a to 40d, the heat medium circulates between the intermediate
heat exchanger 25a and the use-side heat exchanger 35 in which the
cooling load is generated. Further, the heat medium also circulates
between the intermediate heat exchanger 25b and the use-side heat
exchanger 35 in which the heating load is generated. The second
refrigerant flow switching device 28a is switched to the cooling
side (dotted-line side in FIG. 2), whereas the second refrigerant
flow switching device 28b is switched to the heating side
(solid-line side in FIG. 2). The expansion device 26a is fully
opened, the opening and closing device 27 is closed, and the
opening and closing device 29 is closed.
[0105] First, the flow of the heat source-side refrigerant in the
refrigerant circuit A is described. The flow of the heat
source-side refrigerant through the refrigerant circuit A in the
heating main operation mode is the same as the flow of the heat
source-side refrigerant through the refrigerant circuit A in the
heating only operation mode described above. Specifically, the
low-temperature and low-pressure refrigerant is compressed by the
compressor 10 to be discharged as high-temperature and
high-pressure gas refrigerant. The high-temperature and
high-pressure gas refrigerant discharged from the compressor 10
passes through the first refrigerant flow switching device 11 and
then through the refrigerant-use connection pipe 4a and the check
valve 13d to flow out of the outdoor unit 1. The high-temperature
and high-pressure gas refrigerant flowing out of the outdoor unit 1
passes through the refrigerant pipe 4 to flow into the relay unit
2. The high-temperature and high-pressure gas refrigerant flowing
into the relay unit 2 passes through the second refrigerant flow
switching device 28b to flow into the intermediate heat exchanger
25b functioning as the condenser.
[0106] The gas refrigerant flowing into the intermediate heat
exchanger 25b is condensed and liquefied while rejecting heat to
the heat medium circulating through the heat medium circuit B, and
turns into liquid refrigerant. The liquid refrigerant flowing out
of the intermediate heat exchanger 25b is expanded by the expansion
device 26b to turn into low-pressure two-phase refrigerant. The
low-pressure two-phase refrigerant flows into the intermediate heat
exchanger 25a functioning as the evaporator through the fully
opened expansion device 26a. The low-pressure two-phase refrigerant
flowing into the intermediate heat exchanger 25a removes heat from
the heat medium circulating through the heat medium circuit B to
evaporate and cool the heat medium. The low-pressure two-phase
refrigerant flows out of the intermediate heat exchanger 25a, and
flows out of the relay unit 2 through the second refrigerant flow
switching device 28a to flow into the outdoor unit 1 again through
the refrigerant pipe 4.
[0107] The low-temperature and low-pressure two-phase refrigerant
flowing into the outdoor unit 1 passes through the check valve 13b
to flow into the heat source-side heat exchanger 12 functioning as
the evaporator. Then, the refrigerant flowing into the heat
source-side heat exchanger 12 removes heat from the outside air in
the heat source-side heat exchanger 12 to turn into low-temperature
and low-pressure gas refrigerant. The low-temperature and
low-pressure gas refrigerant flowing out of the heat source-side
heat exchanger 12 is sucked into the compressor 10 again through
the first refrigerant flow switching device 11 and the accumulator
19.
[0108] At this time, the opening degree of the expansion device 26b
is controlled so that subcool (degree of subcooling) of the
refrigerant at the outlet of the intermediate heat exchanger 25b
becomes a target value. The subcool may be controlled by the
expansion device 26a while the expansion device 26b is fully
opened. Note that, when the temperature at the intermediate
position in the intermediate heat exchangers 25 can be measured,
the temperature at the intermediate position may be used in place
of the converted saturation temperature. In this case, a pressure
sensor is not required to be installed, and the system can be
constructed at low cost.
[0109] Next, the flow of the heat medium in the heat medium circuit
B is described.
[0110] In the heating main operation mode, the heating energy of
the heat source-side refrigerant is transferred to the heat medium
in the intermediate heat exchanger 25b. The heated heat medium is
controlled to flow through the heat medium pipe 5 by the pump 31b.
Further, in the heating main operation mode, the cooling energy of
the heat source-side refrigerant is transferred to the heat medium
in the intermediate heat exchanger 25a. The cooled heat medium is
controlled to flow through the heat medium pipe 5 by the pump 31a.
The heated heat medium, which is pressurized by the pump 31b to
flow out of the pump 31b, flows into the use-side heat exchanger 35
in which the heating load is generated, through the integrated heat
medium flow switching devices 40. On the other hand, the cooled
heat medium, which is pressurized by the pump 31a to flow out of
the pump 31a, flows into the use-side heat exchanger 35 in which
the cooling load is generated, through the integrated heat medium
flow switching devices 40.
[0111] At this time, when the connected indoor unit 3 is performing
the heating operation, the integrated heat medium flow switching
device 40 is switched so that the connected indoor unit 3 forms the
heat medium circuit B between the intermediate heat exchanger 25b
functioning as the condenser and the pump 31b. When the connected
indoor unit 3 is performing the cooling operation, the integrated
heat medium flow switching device 40 is switched so that the
connected indoor unit 3 forms the heat medium circuit B between the
intermediate heat exchanger 25a functioning as the evaporator and
the pump 31a. Specifically, the heat medium to be supplied to the
indoor units 3 can be switched to function as a heating heat medium
or cooling heat medium by the integrated heat medium flow switching
devices 40.
[0112] In the use-side heat exchangers 35, the cooling operation
for the indoor space 7 by heat removal by the heat medium from the
indoor air or the heating operation for the indoor space 7 by heat
rejection by the heat medium to the indoor air is performed. At
this time, the heat medium flows into the use-side heat exchangers
35 after the flow rate of the heat medium is controlled to the flow
rate necessary for covering the indoor air conditioning load by the
functions of the integrated heat medium flow switching devices
40.
[0113] The heat medium, which is used for the heating operation and
passes through the use-side heat exchangers 35 to have a slightly
reduced temperature, passes through the integrated heat medium flow
switching devices 40 to flow into the intermediate heat exchanger
25b. After the heat medium flowing into the intermediate heat
exchanger 25b exchanges heat with the heat source-side refrigerant
to be heated, the heat medium is sucked into the pump 31b again.
The heat medium, which is used for the cooling operation and passes
through the use-side heat exchangers 35 to have a slightly
increased temperature, passes through the integrated heat medium
flow switching devices 40 to flow into the intermediate heat
exchanger 25a. After the heat medium flowing into the intermediate
heat exchanger 25a exchanges heat with the heat source-side
refrigerant to be cooled, the heat medium is sucked into the pump
31a again.
[0114] The heat medium heated by the intermediate heat exchanger
25b and the heat medium cooled by the intermediate heat exchanger
25a are introduced into the use-side heat exchangers 35
respectively having the heating load and the cooling load therein
without being mixed in the relay unit 2 under the functions of the
integrated heat medium flow switching devices 40.
[0115] The integrated heat medium flow switching devices 40 control
the heat medium flow rate flowing into the use-side heat exchangers
35 as described above. The control on the integrated heat medium
flow switching devices 40 is specifically as follows. Specifically,
on the heating side, the integrated heat medium flow switching
devices 40 are controlled so that the temperature difference
between the temperature detected by the temperature sensor 55b and
the temperature of the heat medium flowing out of the use-side heat
exchangers 35 is kept to a target value. On the cooling side, the
integrated heat medium flow switching devices 40 are controlled so
that the temperature difference between the temperature of the heat
medium flowing out of the use-side heat exchangers 35 and the
temperature detected by the temperature sensor 55a is kept to a
target value. By controlling the integrated heat medium flow
switching devices 40 to control the heat medium flow rate flowing
into the use-side heat exchangers 35 in the above-mentioned manner,
the air conditioning load for the indoor space 7 can be
appropriately treated.
[Mixed Operation Mode: Cooling Main Operation]
[0116] Now, the cooling main operation mode of the mixed operation,
in which the heating load is generated in any of the use-side heat
exchangers 35 and the cooling load is generated in the remaining
use-side heat exchangers 35, is described.
[0117] FIG. 6 is a refrigerant circuit diagram illustrating the
flow of the refrigerant in the cooling main operation mode of the
air-conditioning apparatus 100 according to the embodiment of the
present invention. In FIG. 6, the pipes indicated by the thick
lines are the pipes through which the heat source-side refrigerant
circulates. Further, in FIG. 6, the direction of the flow of the
heat source-side refrigerant is indicated by the solid arrows,
whereas the direction of the flow of the heat medium is indicated
by the dashed arrows.
[0118] The outline of differences between the main operation and
the cooling only operation is now first described. The expansion
device 26a and the expansion device 26b are both controlled to
function as expansion valves during the cooling only operation, but
one of the expansion devices 26a and 26b is fully opened and the
other thereof is controlled to function as the expansion valve
during the cooling main operation. In this manner, both the
intermediate heat exchanger 25a and the intermediate heat exchanger
25b function as the evaporators during the cooling only operation,
whereas the intermediate heat exchanger 25b functions as the
condenser and the intermediate heat exchanger 25a functions as the
evaporator during the cooling main operation similarly to the
heating main operation.
[0119] In the case of the cooling main operation mode illustrated
in FIG. 6, in the outdoor unit 1, the first refrigerant flow
switching device 11 is switched so that the heat source-side
refrigerant discharged from the compressor 10 flows into the heat
source-side heat exchanger 12. In the relay unit 2, the pump 31a
and the pump 31b are driven to open the integrated heat medium flow
switching devices 40. By opening the integrated heat medium flow
switching devices 40a to 40d, the heat medium circulates between
the intermediate heat exchanger 25a and the use-side heat exchanger
35 in which the heating load is generated. Further, the heat medium
also circulates between the intermediate heat exchanger 25b and the
use-side heat exchanger 35 in which the cooling load is generated.
The second refrigerant flow switching device 28a is switched to the
cooling side (dotted-line side in FIG. 2), whereas the second
refrigerant flow switching device 28b is switched to the heating
side (solid line side in FIG. 2). The expansion device 26b is fully
opened, the opening and closing device 27 is closed, and the
opening and closing device 29 is closed.
[0120] The flow of the heat source-side refrigerant in the
refrigerant circuit A in the cooling main operation mode is the
same as the flow of the heat source-side refrigerant in the
refrigerant circuit A in the cooling only operation mode described
above. Further, the flow of the heat medium in the heat medium
circuit B in the cooling main operation mode is the same as the
flow of the heat medium in the heat medium circuit B in the heating
main operation described above.
[0121] Even in the cooling main operation mode, the integrated heat
medium flow switching devices 40 control the heat medium flow rate
flowing into the use-side heat exchangers 35 as described above.
The control on the integrated heat medium flow switching devices 40
is specifically as follows. Specifically, on the cooling side, the
integrated heat medium flow switching devices 40 are controlled so
that the temperature difference between the temperature of the heat
medium flowing out of the use-side heat exchangers 35 and the
temperature detected by the temperature sensor 55b is kept to the
target value. On the heating side, the integrated heat medium flow
switching devices 40 are controlled so that the temperature
difference between the temperature detected by the temperature
sensor 55a and the temperature of the heat medium flowing out of
the use-side heat exchangers 35 is kept to the target value. By
controlling the integrated heat medium flow switching devices 40 to
control the heat medium flow rate flowing into the use-side heat
exchangers 35 in the above-mentioned manner, the air conditioning
load for the indoor space 7 can be appropriately treated.
[Structure of Integrated Heat Medium Flow Switching Devices 40]
[0122] Next, a specific structure of the integrated heat medium
flow switching devices 40 is described.
[0123] FIG. 7 are explanatory diagrams illustrating the integrated
heat medium flow switching devices 40 included in the relay unit 2
illustrated in FIG. 1. FIG. 7(a) is an illustration of the four
integrated heat medium flow switching devices 40 (40a to 40d) and a
conceptual perspective view of a configuration of connection
between the integrated heat medium flow switching devices 40 and
each of the intermediate heat exchangers 25 and the indoor units 3.
FIG. 7(b) is a longitudinal sectional view of the integrated heat
medium flow switching device 40. FIG. 8 is a conceptual diagram
illustrating a configuration of the valve body 44 illustrated in
FIG. 7.
[0124] The integrated heat medium flow switching device 40 includes
a body 60, a pair of heat medium delivery main pipes 42a and 42b, a
pair of heat medium delivery main pipes 43a and 43b, the single
valve body 44 formed in a shaft-like shape, an indoor-unit supply
pipe 45, and an indoor-unit return pipe 46.
[0125] The body 60 is made of PPS or a resin. However, other
materials can also be used as long as a heat capacity of the heat
medium is not significantly lost due to heat conduction and heat
rejection to the body 60. The body 60 includes the pair of heat
medium delivery main pipes 42a and 42b and the pair of heat medium
delivery main pipes 43a and 43b, which are opposed to each other
through the valve body 44 described below therebetween and are
provided to penetrate the body 60 in parallel to each other. The
pair of heat medium delivery main pipes 42a and 42b is connected to
the intermediate heat exchanger 25a by a pipe (not shown), whereas
the pair of heat medium delivery main pipes 43a and 43b is
connected to the intermediate heat exchanger 25b by a pipe (not
shown).
[0126] The body 60 includes a valve chamber 60a that intersects the
pair of heat medium delivery main pipes 42a and 42b and the pair of
heat medium delivery main pipes 43a and 43b. In the valve chamber
60a, the valve body 44 is provided so as to be axially rotatable.
The valve body 44 is rotationally driven by the driving device
41.
[0127] The indoor-unit supply pipe 45 is connected to an indoor
unit-side inlet opening 44c of the valve body 44, which is
described later. Further, the indoor-unit return pipe 46 is
connected to the body 60, and hence an end portion of the
indoor-unit return pipe 46 is open to the valve chamber 60a.
[0128] As illustrated in FIG. 8, the valve body 44 includes a pair
of selection-side openings 44a and 44b formed in an outer
peripheral surface of the valve body 44 so as to be spaced apart
from each other in an axial direction of the valve body 44, and an
indoor unit-side inlet opening 44c that is formed at an axial end
portion of the valve body 44 and is to be connected to the inlet
side of the use-side heat exchanger 35. The valve body 44 further
includes two indoor unit-side outlet openings 44d and 44e formed in
the outer peripheral surface of the valve body 44 at positions
opposed to each other.
[0129] The pair of selection-side openings 44a and 44b is brought
into communication with the pair of heat medium delivery main pipes
42a and 42b or the pair of heat medium delivery main pipes 43a and
43b depending on a rotation stop position of the valve body 44. The
indoor unit-side outlet opening 44d is formed in the valve body 44
so as to be brought into communication with the indoor-unit return
pipe 46 when the pair of selection-side openings 44a and 44b is
brought into communication with the pair of heat medium delivery
main pipes 42a and 42b. Further, the indoor unit-side outlet
opening 44e is formed in the valve body 44 so as to be brought into
communication with the indoor-unit return pipe 46 when the pair of
selection-side openings 44a and 44b is brought into communication
with the pair of heat medium delivery main pipes 43a and 43b.
[0130] As illustrated in FIG. 8, the valve body 44 includes the
pair of selection-side openings 44a and 44b formed in the outer
peripheral surface of the valve body 44 so as to be spaced apart
from each other in the axial direction of the valve body 44, and
the indoor unit-side inlet opening 44c that is formed at the axial
end portion of the valve body 44 and is to be connected to the
inlet side of the use-side heat exchanger 35. The valve body 44
further includes the two indoor unit-side outlet openings 44d and
44e formed in the outer peripheral surface of the valve body 44 at
positions opposed to each other. The indoor unit-side outlet
opening 44d is formed in the valve body 44 so as to be brought into
communication with the indoor-unit return pipe 46 when the pair of
selection-side openings 44a and 44b is brought into communication
with the pair of heat medium delivery main pipes 42a and 42b.
Further, the indoor unit-side outlet opening 44e is formed in the
valve body 44 so as to be brought into communication with the
indoor-unit return pipe 46 when the pair of selection-side openings
44a and 44b is brought into communication with the pair of heat
medium delivery main pipes 43a and 43b.
[0131] In the valve body 44, three passages including a supply
passage X1, a selective return passage X2, and a selective return
passage X3 are formed, as indicated by the arrows in FIG. 8. The
supply passage X1 is a passage through which the selection-side
opening 44a and the indoor unit-side inlet opening 44c are brought
into communication with each other. The selective return passage X2
is a passage through which the supply passage X1, the indoor
unit-side outlet opening 44d, and the selection-side opening 44b
are brought into communication with each other. The selective
return passage X3 is a passage through which the indoor unit-side
outlet opening 44e and the selection-side opening 44b are brought
into communication with each other.
[0132] Further, in the valve body 44, an adiabatic wall 61 is
formed between the supply passage X1 and the selective return
passages X2 and X3 so that the heat capacity is prevented from
being transferred and received between the heat media passing
through the respective passages. The adiabatic wall 61 is formed in
the valve body 44 in this structure, but the structure is not
limited thereto as long as the heat capacity is not transferred and
received between the heat media.
[0133] In the integrated heat medium flow switching devices 40
configured as described above, when the valve body 44 is axially
driven by the driving device 41, the pair of selection-side
openings 44a and 44b is brought into communication with the pair of
heat medium delivery main pipes 42a and 42b or the pair of heat
medium delivery main pipes 43a and 43b. As a result, the heat
medium passage is switched to the heat medium delivery main pipes
42a and 42b or the heat medium delivery main pipes 43a and 43b.
Specifically, a destination of connection of the indoor unit 3 can
be switched to the intermediate heat exchanger 25a or the
intermediate heat exchanger 25b.
[0134] A portion surrounded by the dotted line on the left of the
adiabatic wall 61 in FIG. 7(b) corresponds to the heat medium flow
switching device 32 illustrated in FIG. 2, whereas a portion
surrounded by the dotted line on the right of the adiabatic wall 61
in FIG. 7(b) corresponds to the heat medium flow switching device
33 illustrated in FIG. 2. Specifically, the integrated heat medium
flow switching device 40 has a structure formed by integrating the
heat medium flow switching devices 32 and 33 by integrating the
valve bodies of the heat medium flow switching devices 32 and
33.
[0135] As described above, in this embodiment, for achieving the
configuration in which the destination of connection of the indoor
unit 3 is switched to the intermediate heat exchanger 25a or the
intermediate heat exchanger 25b, the valve bodies of the heat
medium flow switching devices 32 and 33 are integrated. In this
manner, two driving devices, which are otherwise required to
respectively drive the two valve bodies, can be replaced by the
shared single driving device 41. As a result, the space saving can
be improved. In addition, driving power can be reduced to improve
the energy saving.
[0136] Further, in the integrated heat medium flow switching device
40, the opening area (communicating area) between the openings (the
pair of selection-side openings 44a and 44b and the indoor
unit-side outlet openings 44d and 44e) formed in the outer
peripheral surface of the valve body 44 and the heat medium
delivery main pipe 42 or the heat medium delivery main pipe 43
changes depending on the rotation stop position of the valve body
44. Therefore, by configuring the driving device 41 so as to be
capable of controlling the rotation stop position of the valve body
44 such as a stepping motor, the flow rate of the heat medium can
be controlled. In a case where only the flow switching function is
required without the need of the flow-rate controlling function in
the integrated heat medium flow switching devices 40, a device
simply capable of switching (such as an ON/OFF power supply) may be
used.
[0137] As described above, the integrated heat medium flow
switching device 40 can control the passage and the flow rate
depending on the rotation stop position of the valve body 44.
[0138] The integrated heat medium flow switching devices 40 are
provided so as to correspond to the plurality of indoor units 3 in
a one-by-one fashion as described above. All the integrated heat
medium flow switching devices 40 included in the relay unit 2 may
be formed integrally. Specifically, the bodies 60 of all the
integrated heat medium flow switching devices 40 are first formed
integrally as the common body. Then, the heat medium delivery main
pipes 42 and the heat medium delivery main pipes 43 of all the
integrated heat medium flow switching devices 40 are formed as a
single pipe shared by all the integrated heat medium flow switching
devices 40. In this manner, all (four in this case) integrated heat
medium flow switching devices 40 can be formed integrally. The
configuration is not limited to that in which all the integrated
heat medium flow switching devices 40 are integrated, and some of
the integrated heat medium flow switching devices 40 may be
integrated.
[0139] Further, the integrated heat medium flow switching devices
40 may be separated for the respective indoor units 3 so that the
adjacent integrated heat medium flow switching devices 40 are
connectable to each other.
[0140] Next, an operation (flow switching and flow rate control) of
the integrated heat medium flow switching device 40 is described.
Now, the following three cases are described.
[0141] 1. Case where the indoor units 3 are connected to the
intermediate heat exchanger 25a side.
[0142] 2. Case where the indoor units 3 are connected to the
intermediate heat exchanger 25b side.
[0143] 3. Case where the indoor unit 3 is separated from the heat
medium circuit B.
[Case where Indoor Units 3 are Connected to Intermediate Heat
Exchanger 25a Side]
[0144] FIG. 9 are explanatory diagrams of the rotation stop
position of the valve body 44 of the integrated heat medium flow
switching device 40 and the flow of the heat medium in a state in
which the integrated heat medium flow switching devices 40 included
in the relay unit 2 illustrated in FIG. 1 are switched to the
intermediate heat exchanger 25a side. FIG. 9(a) is an illustration
of the four integrated heat medium flow switching devices 40a to
40d, and FIG. 9(b) is a longitudinal sectional view of the
integrated heat medium flow switching device 40. In FIG. 9, the
direction of the flow of the heat medium is indicated by the solid
arrows.
[0145] In the case where the integrated heat medium flow switching
device 40 is switched to the intermediate heat exchanger 25a side,
the valve body 44 is rotated by the driving device 41 to allow the
internal passage in the valve body 44 to be brought into
communication with the pair of heat medium delivery main pipes 42a
and 42b as illustrated in FIG. 9(b). Specifically, the pair of
selection-side openings 44a and 44b is brought into communication
with the pair of heat medium delivery main pipes 42a and 42b so
that the indoor unit-side outlet opening 44d is brought into
communication with the indoor unit return pipe 46.
[0146] In the integrated heat medium flow switching device 40, the
heat medium, which is pressurized by the pump 31 to flow out
thereof, flows into the heat medium delivery main pipe 42a (the
arrow a1). The heat medium flowing into the heat medium delivery
main pipe 42a passes through the supply passage X1 to be delivered
to the connected indoor unit 3 (the arrows a2). The heat medium,
which is delivered to the connected indoor unit 3 and exchanges
heat with the indoor space 7 in the use-side heat exchanger 35
included in the connected indoor unit 3, flows into the integrated
heat medium flow switching device 40 again. Specifically, the heat
medium, which flows into the integrated heat medium flow switching
device 40, first flows into the indoor-unit return pipe 46 (the
arrows a3) and passes through the selective return passage X2 to
flow into the heat medium delivery main pipe 42b (the arrow a4).
Then, the heat medium, which passes through the heat medium
delivery main pipe 42b, flows out of the integrated heat medium
flow switching device 40 to flow into the intermediate heat
exchanger 25a again (the arrow a5). As described above, by
switching the rotation stop position of the valve body 44 of the
integrated heat medium flow switching device 40, the heat medium
circuit B that connects the intermediate heat exchanger 25a and the
indoor units 3 is formed.
[0147] Through the valve body 44, the heat medium passing through
the supply passage X1 to flow from the heat medium delivery main
pipe 42a to the connected indoor unit 3 and the heat medium
returning from the connected indoor unit 3 to the integrated heat
medium flow switching device 40 to pass through the selective
return passage X2 pass. The heat media have a temperature
difference, but the transfer and reception of the heat capacity
between the heat media is suppressed by the adiabatic wall 61.
[0148] The rotation stop position of the valve body 44 and the flow
of the heat medium inside the valve body 44 in the case where the
integrated heat medium flow switching device 40 is switched to the
intermediate heat exchanger 25a side are described above. The
integrated heat medium flow switching device 40 also controls the
flow rate of the heat medium flowing through the connected indoor
unit 3 as described above in addition to the flow switching.
[0149] For the control of the flow rate of the heat medium, the
rotation stop position of the valve body 44 is controlled by the
driving device 41. When the opening area of the passage is to be
enlarged, the rotation stop position of the valve body 44 is
controlled so that an opening area of a communicating portion
between the pair of heat medium delivery main pipes 42a and 42b and
the pair of selection-side openings 44a and 44b is increased. On
the contrary, when the opening area of the passage is to be
reduced, the rotation stop position of the valve body 44 is
controlled so that the opening area of the communicating portion
between the pair of heat medium delivery main pipes 42a and 42b and
the pair of selection-side openings 44a and 44b is reduced.
[Case where Indoor Units 3 are Connected to Intermediate Heat
Exchanger 25b Side]
[0150] FIG. 10 are explanatory diagrams of the rotation stop
position of the integrated heat medium flow switching device 40 and
the flow of the heat medium in a state in which the integrated heat
medium flow switching devices 40 included in the relay unit 2
illustrated in FIG. 1 are switched to the intermediate heat
exchanger 25b side. FIG. 10(a) is an illustration of the four
integrated heat medium flow switching devices 40a to 40d, and FIG.
10(b) is a longitudinal sectional view of the integrated heat
medium flow switching device 40. In FIG. 10, the direction of the
flow of the heat medium is indicated by the solid arrows.
[0151] In the case where the integrated heat medium flow switching
device 40 is switched to the intermediate heat exchanger 25a side,
the valve body 44 is rotated by the driving device 41 to allow the
passage in the valve body 44 to be brought into communication with
the pair of heat medium delivery main pipes 43a and 43b as
illustrated in FIG. 10. Specifically, the pair of selection-side
openings 44a and 44b is brought into communication with the pair of
heat medium delivery main pipes 43a and 43b so that the indoor
unit-side outlet opening 44e is brought into communication with the
indoor unit return pipe 46.
[0152] In the integrated heat medium flow switching device 40, the
heat medium, which is pressurized by the pump 31 to flow out
thereof, flows into the heat medium delivery main pipe 43a (the
arrow a1). The heat medium flowing into the heat medium delivery
main pipe 43a passes through the supply passage X1 to be delivered
to the connected indoor unit 3 (the arrows a2). The heat medium,
which is delivered to the connected indoor unit 3 and exchanges
heat with the indoor space 7 in the use-side heat exchanger 35
included in the connected indoor unit 3, flows into the integrated
heat medium flow switching device 40 again. Specifically, the heat
medium, which flows into the integrated heat medium flow switching
device 40, first flows into the indoor-unit return pipe 46 (the
arrows a3) and passes through the selective return passage X3 to
flow into the heat medium delivery main pipe 43b (the arrow a4).
Then, the heat medium, which passes through the heat medium
delivery main pipe 43b, flows out of the integrated heat medium
flow switching device 40 to flow into the intermediate heat
exchanger 25b again (the arrow a5). As described above, by
switching the rotation stop position of the valve body 44 of the
integrated heat medium flow switching device 40, the heat medium
circuit B that connects the intermediate heat exchanger 25b and the
indoor units 3 is formed.
[0153] Through the valve body 44, the heat medium passing through
the supply passage X1 to flow from the heat medium delivery main
pipe 43a to the connected indoor unit 3 and the heat medium
returning from the connected indoor unit 3 to the integrated heat
medium flow switching device 40 to pass through the selective
return passage X3 pass. The heat media have a temperature
difference, but the transfer and reception of the heat capacity
between the heat media is suppressed by the adiabatic wall 61.
[0154] The rotation stop position of the valve body 44 and the flow
of the heat medium inside the valve body 44 in the case where the
integrated heat medium flow switching device 40 is switched to the
intermediate heat exchanger 25b side are described above. The
integrated heat medium flow switching device 40 also controls the
flow rate of the heat medium flowing through the connected indoor
unit 3 as described above in addition to the flow switching.
[0155] For the control of the flow rate of the heat medium, the
rotation position of the valve body 44 is controlled by the driving
device 41. When the opening area of the passage is to be enlarged,
the rotation stop position of the valve body 44 is controlled so
that an opening area of a communicating portion between the pair of
heat medium delivery main pipes 43a and 43b and the pair of
selection-side openings 44a and 44b is increased. On the contrary,
when the opening area of the passage is to be reduced, the rotation
stop position of the valve body 44 is controlled so that the
opening area of the communicating portion between the pair of heat
medium delivery main pipes 43a and 43b and the pair of
selection-side openings 44a and 44b is reduced.
[0156] When the air-conditioning apparatus 100 is currently
operating in, for example, the heating main operation mode, the
intermediate heat exchanger 25b functions as the condenser, and the
heating heat medium flows through the pair of heat medium delivery
main pipes 43a and 43b, which is in communication with the
intermediate heat exchanger 25b, as illustrated in FIG. 7. On the
other hand, the intermediate heat exchanger 25a functions as the
evaporator, and the cooling heat medium flows through the pair of
heat medium delivery main pipes 42a and 42b, which is in
communication with the intermediate heat exchanger 25a. When, for
example, the indoor unit 3d is switched from the heating operation
to the cooling operation, the controller 50 drives the driving
device 41 to rotate the valve body 44 of the integrated heat medium
flow switching device 40d from a state illustrated in FIG. 10(b) to
a state illustrated in FIG. 9(a). As a result, the cooling heat
medium having a temperature based on the cooling operation, which
flows through the pair of heat medium delivery main pipes 42a and
42b, can be sent to the indoor unit 3d.
[Case where Indoor Unit 3 is Separated from Heat Medium Circuit
B]
[0157] The heat medium is required so as not to be sent to the
indoor unit 3 whose operation is stopped so that the heat is not
exchanged between the heat medium and the indoor air in the
use-side heat exchanger 35. Therefore, the indoor unit 3 is
separated from the heat medium circuit B by the integrated heat
medium flow switching device 40. Now, an operation of the
integrated heat medium flow switching device 40 in the case where
the indoor unit 3 is separated from the heat medium circuit B is
described.
[0158] FIG. 11 are explanatory diagrams of the rotation stop
position of the integrated heat medium flow switching device 40 and
the flow of the heat medium in the case where the indoor unit 3 is
separated from the heat medium circuit B by the integrated heat
medium flow switching device 40 included in the relay unit 2
illustrated in FIG. 1. FIG. 11(a) is an illustration of the four
integrated heat medium flow switching devices 40a to 40d, and FIG.
11(b) is a longitudinal sectional view of the integrated heat
medium flow switching device 40. In FIG. 11(b), the direction of
the flow of the heat medium is indicated by the solid arrows.
[0159] When the indoor unit 3 is to be separated from the heat
medium circuit B, the valve body 44 is rotated by the driving
device 41 and is stopped at a position illustrated in FIG. 11(b).
Specifically, the valve body 44 is stopped at a position at which
the pair of selection-side openings 44a and 44b and the indoor
unit-side outlet opening 44d are not brought into communication
with any of the pair of heat medium delivery main pipes 42a and
42b, the pair of heat medium delivery main pipes 43a and 43b, and
the indoor-unit return pipe 46. Specifically, the rotation stop
position of the valve body 44 is controlled to the position at
which the opening degree is zero. As a result, the passage between
the relay unit 2 and the indoor unit 3 is interrupted so that the
indoor unit 3 can be separated from the heat medium circuit B.
[0160] The integrated heat medium flow switching devices 40 are
provided so as to respectively correspond to the indoor units 3.
For each of the indoor units 3, the flow of the heat medium into
the indoor unit 3 and the interruption thereof can be selected
individually. Therefore, even if some of the four indoor units 3
are performing the heating or cooling operation, the heat medium
can be prevented from flowing into the other indoor unit(s) 3 in
the stopped state.
[0161] The indoor unit 3 can be separated from the heat medium
circuit B as described above, and hence the following effects can
also be produced. Specifically, when a component included in the
heat medium circuit B in the relay unit 2 is replaced and
maintained, the indoor unit 3 can be separated from the heat medium
circuit B in advance. Therefore, during work, the amount of heat
medium exhausted from the heat medium circuit B can be reduced to
be minimum necessary. As a result, working efficiency can be
improved in elimination of the need of refilling the heat medium or
the like. Further, the effects can be similarly produced even when
one or more of the plurality of indoor units 3 connected to the
relay unit 2 is replaced.
[0162] As described above, according to this embodiment, the valve
bodies of the heat medium flow switching device 32 and the heat
medium flow switching device 33 are integrated. The driving
devices, which are otherwise required separately, can be formed as
the shared single driving device 41. Therefore, the number of
driving devices 41 can be reduced to achieve energy saving and
space saving. Further, the functions of both the heat medium flow
switching device 32 and the heat medium flow switching device 33
can be demonstrated by the singe integrated heat medium flow
switching device 40. Thus, the number of heat medium flow switching
devices can be substantially reduced to improve ease of maintenance
and ease of assembly.
[0163] Further, there is provided the structure in which the valve
body 44 is formed in the shaft-like shape and the internal passage
in the valve body 44 is brought into communication with the pair of
heat medium delivery main pipes 42a and 42b or the pair of heat
medium delivery main pipes 43a and 43b depending on the rotation
stop position of the valve body 44. By the structure described
above, the integrated heat medium flow switching device 40, in
which the heat medium flow switching device 32 and the heat medium
flow switching device 33 are integrated, can be formed.
[0164] Further, the pair of selection-side openings 44a and 44b is
formed in the outer peripheral surface of the valve body 44 so that
the communicating area in communication with the pair of heat
medium delivery main pipes 42a and 42b or the pair of heat medium
delivery main pipes 43a and 43b changes based on the rotation
position of the valve body 44. As a result, the integrated heat
medium flow switching device 40 can control the flow rate of the
heat medium flowing in the use-side heat exchanger 35. Therefore,
by the operation of the single driving device 41, both of the flow
switching function and the flow-rate controlling function can be
performed simultaneously. Accordingly, even when the number of the
connected indoor units 3 is increased, a minimum number of the
driving device 41 can be mounted to achieve the energy saving and
the space saving.
[0165] Further, by stopping the valve body 44 at the rotation stop
position at which the selection-side openings 44a and 44b of the
valve body 44 are not brought into communication with any of the
pair of heat medium delivery main pipes 42a and 42b and the pair of
heat medium delivery main pipes 43a and 43b, the passage between
the relay unit 2 and the indoor unit 3 can be interrupted. In the
related-art air-conditioning apparatus, for the maintenance
including replacement of a component of the heat medium circuit,
the heat medium is required to be temporarily entirely exhausted
from the heat medium circuit. After the maintenance, refilling is
required. However, in the air-conditioning apparatus 100 according
to this embodiment, the indoor unit 3 can be separated from the
heat medium circuit B. Therefore, reduction of the amount of
exhausted heat medium and simplification of the maintenance work
are enabled for the following reasons.
[0166] Specifically, at the time of implementation of the
maintenance of the heat medium circuit B, the indoor unit 3 is
separated from the heat medium circuit B. In this manner, the
component of the heat medium circuit, which is included in the
relay unit 2, can be replaced while the heat medium is kept in the
use-side heat exchangers 35 and the heat medium pipes 5. Therefore,
the amount of exhausted heat medium at the time of replacement of
the component or the maintenance can be reduced, thereby enabling
the simplification of the maintenance work. As a result, ease of
system maintenance can be improved.
[0167] Further, in this embodiment, the number of heat medium flow
switching devices can be substantially reduced as described above.
Thus, a number of times of maintenance such as the component
replacement can also be reduced, thereby enabling the improvement
of convenience in system use.
[0168] Further, the passage from the relay unit 2 to the indoor
unit 3 is closed by the integrated heat medium flow switching
device 40 so that the heat medium is not sent to the indoor unit 3
whose operation is stopped. As a result, delivery power of the
pumps 31 that is the heat medium delivery device can be reduced,
while workability can be improved.
[0169] Further, the case where the accumulator 19 is included in
the air-conditioning apparatus 100 has been described as an example
in this embodiment, but the accumulator 19 is not required to be
provided. In general, air-sending devices are mounted to the heat
source-side heat exchanger 12 and the use-side heat exchangers 35
to accelerate the condensation or evaporation by sending air in
many cases. However, the heat source-side heat exchanger and the
use-side heat exchangers are not limited thereto. For example, a
panel heater using radiation or the like can also be used as the
use-side heat exchanger 35, whereas a water-cooled type heat
exchanger that allows the heat to move through water or the
antifreezing solution can also be used as the heat source-side heat
exchanger. Specifically, any kind of heat source-side heat
exchanger and use-side heat exchanger can be used as the heat
source-side heat exchanger 12 and the use-side heat exchanger 35 as
long as a structure thereof can reject or remove heat.
[0170] Further, the case where the number of use-side exchangers 35
is four has been described as an example in this embodiment, but
the number of use-side exchangers 35 is not particularly limited.
Further, the case where the number of intermediate heat exchangers
25a and 25b is two has been described as an example, but it is
apparent that the number of intermediate heat exchangers 25a and
25b is not limited. Any number of intermediate heat exchangers may
be installed as long as the configuration is such that the heat
medium can be cooled or/and heated. Further, the number of each of
the pumps 31a and 31b is not limited to one. A plurality of
small-capacity pumps may be arranged in parallel and connected.
[0171] There has been described above the configuration in which
the number of intermediate heat exchangers 25 is two and the valve
bodies of all the heat medium flow switching devices (specifically,
the two heat medium flow switching devices corresponding to the
heat medium flow switching device 32 and the heat medium flow
switching device 33) required for switching to any of the
intermediate heat exchangers are integrated. When the number of
intermediate heat exchangers 25 is three or more, a switching
device capable of switching to connect the indoor unit 3 to any of
the three or more intermediate heat exchangers 25 can be configured
by combining a plurality of the integrated heat medium flow
switching devices 40 having the configuration illustrated in FIG.
7. This configuration corresponds to a configuration in which some
of the plurality of valve bodies included in the plurality of heat
medium flow switching devices that are necessary to switch the
indoor unit 3 to any of the intermediate heat exchangers 25 are
integrated. Therefore, even in the case of the configuration
described above, the number of driving devices 41 can be reduced to
obtain the effects of space saving and energy saving.
[0172] The integrated heat medium flow switching device 40 has the
configuration in which the pair of heat medium delivery main pipes
42a and 42b and the pair of heat medium delivery main pipes 43a and
43b are provided in the body 60 in the above description, yet the
integrated heat medium flow switching device 40 may be configured
as illustrated in FIG. 12. Specifically, the body 60 may be reduced
in size so that the pair of heat medium delivery main pipes 42a and
42b and the pair of heat medium delivery main pipes 43a and 43b are
exposed from the body 60. Even in this case, the same functions and
effects as those described above can be obtained. Further, even in
the case of the configuration described above, a modified example
applied to the same portion as that described above can be
similarly applied.
[0173] The second refrigerant flow switching devices 28 are
illustrated as four-way valves in FIG. 2 or the like, but the
second refrigerant flow switching devices are not limited thereto.
A plurality of two-way flow switching valves or three-way flow
switching valves may be used to configure the second refrigerant
flow switching device so that the refrigerant flows in the same
manner.
REFERENCE SIGNS LIST
[0174] outdoor unit 2 relay unit 3 (3a-3d) indoor unit 4
refrigerant pipe 4a refrigerant-use connection pipe 4b
refrigerant-use connection pipe 5 heat-medium pipe 6 outdoor space
7 indoor space 8 space 9 construction 10 compressor 11 first
refrigerant flow switching device 12 heat source-side heat
exchanger 13a check valve 13b check valve 13c check valve 13d check
valve 19 accumulator 20 bypass pipe 25 (25a, 25b) intermediate heat
exchanger 26 (26a, 26b) expansion device 27 opening and closing
device 28 (28a, 28b) second refrigerant flow switching device 29
opening and closing device 31 (31a, 31b) pump 32 (32a, 32b) heat
medium flow switching device 33 (33a-33d) heat medium flow
switching device 35 (35a-35d) use-side heat exchanger 40 (40a-40d)
integrated heat medium flow switching device 41 (41a-41d) driving
device 42 (42a, 42b) heat medium delivery main pipe 43 (43a, 43b)
heat medium delivery main pipe 44 valve body 44a selection-side
opening 44b selection-side opening 44c indoor unit-side inlet
opening 44d indoor unit-side outlet opening 44e indoor unit-side
outlet opening 45 indoor-unit supply pipe 46 indoor-unit return
pipe 50 controller 55 (55a, 55b) temperature sensor 60 body 60a
valve chamber 61 adiabatic wall 100 air-conditioning apparatus A
refrigerant circuit B heat medium circuit X1 supply passage X2
selective return passage X3 selective return passage
* * * * *