Technical Field
[0001] The present invention relates to an air-conditioning device, and a method for controlling
an air-conditioning device.
Background Art
[0002] For example, in an air-conditioning device used in buildings, commercial facilities,
or the like in which an outdoor unit is connected with a plurality of indoor units
(hereinafter, referred to as a "multi-type air-conditioning device"), the outdoor
unit and the indoor units are separately sold in some cases. In this case, since a
plurality of indoor units are freely selectable according to customer demands, the
number of varieties (types or capacities) tends to increase. Accordingly, an outdoor
unit corresponding to a selected indoor unit is selected.
[0003] In addition, characteristics, safety measures, or the like, of an air-conditioning
device depend on a type of refrigerant to be used for the multi-type air-conditioning
device. For example, although R410 refrigerant is incombustible, R32 refrigerant is
slightly combustible. Thus, the air-conditioning device needs to detect coolant leakage.
[0004] Accordingly, an outdoor unit or an indoor unit corresponding to a type of refrigerant
needs to be used. However, since there is a large variety of indoor units, the number
of varieties becomes enormously large when the indoor units are further caused to
correspond to a type of refrigerant.
[0005] As varieties of indoor units increase, supply sides such as manufacturers and sales
companies of indoor units increase types of the indoor units while reducing an amount
of production for each product type, inventory management becomes complicated, and
thus costs rise. As a result, a unit price of the indoor unit rises.
[0006] Note that, a type of a compressor, compressor oil, or the like, also needs to be
changed according to a type of refrigerant. Accordingly, a hardware configuration
of an outdoor unit equipped with a compressor needs to be modified according to a
type of refrigerant in some cases. Meanwhile, as for an indoor unit, although there
is no need for modifying a hardware configuration, a control program needs to be modified
in some cases.
[0007] Patent Document 1 describes an air conditioning control device that is equipped with
a control program storing means for storing a plurality of control programs for controlling
a refrigeration cycle corresponding to a type of refrigerant, and controls the refrigeration
cycle corresponding to the type of refrigerant based on the control programs stored
in the control program storing means.
[0008] The air conditioning control device described in Patent Document 1 determines the
type of refrigerant using a CPU for controlling the indoor unit. This determination
method is performed by calculating a pressure-enthalpy ratio of a refrigerant in a
compression process based on a suction temperature, a suction pressure, a discharge
temperature, and a discharge pressure of a compressor, and comparing the ratio with
pressure-enthalpy ratio data corresponding to the type of refrigerant.
Citation List
Patent Document
Summary of Invention
Technical Problem
[0010] As described above, the air conditioning control device described in Patent Document
1 determines the type of refrigerant using the CPU for controlling the indoor unit.
In addition, Patent Document 1 describes that the indoor unit selects control data
according to the type of refrigerant, transmits the control data or refrigerant type
information to an outdoor unit, and the outdoor unit stores or specifies the received
control data or refrigerant type information.
[0011] In other words, the air conditioning control device described in Patent Document
1 determines the type of refrigerant and sets the control data on the indoor unit
side, and transmits these information to the outdoor unit side.
[0012] However, when the configuration described in Patent Document 1 in which the information
on the type of refrigerant or the like is transmitted from the indoor unit side to
the outdoor unit side is applied to a multi-type air-conditioning device equipped
with a plurality of indoor units having different varieties, information processing
on the outdoor unit becomes complicated.
[0013] Additionally, in a case where the indoor unit side performs the process of determining
the type of refrigerant, the plurality of indoor units wastefully perform the same
processing. Further, there is a possibility that an error occurs in the determination
of the type of refrigerant in the indoor unit side and information indicating a different
type of refrigerant is transmitted to the outdoor unit.
[0014] In light of the foregoing, an object of the present invention is to provide an air-conditioning
device and a method for controlling an air-conditioning device that allow an easy
use of a plurality of indoor units in accordance with the type of refrigerant.
Solution to Problem
[0015] In order to solve the above-described problems, the air-conditioning device and the
method for controlling an air-conditioning device according to the present invention
adopt the following means.
[0016] An air-conditioning device according to a first aspect of the present invention includes:
an outdoor unit, a plurality of indoor units connected with the outdoor unit via refrigerant
piping, an outdoor control means provided in the outdoor unit and configured to control
the outdoor unit, and a plurality of indoor control means provided in the respective
indoor units and configured to control the respective indoor units, in which the outdoor
control means transmits a refrigerant type signal indicating a type of refrigerant
to be used or a function necessity signal indicating function necessity corresponding
to a type of refrigerant to the plurality of indoor control means, and the indoor
control means performs control corresponding to a type of refrigerant indicated by
the refrigerant type signal received from the outdoor control means or control corresponding
to a function indicated by the function necessity signal.
[0017] The air-conditioning device according to this configuration includes the outdoor
unit, and the plurality of indoor units connected with the outdoor unit via the refrigerant
piping. The outdoor unit is controlled by the outdoor control means provided in the
outdoor unit. Each of the indoor units is controlled by the indoor control means provided
in each of the indoor units.
[0018] The indoor unit connected with the outdoor unit needs to be controlled according
to the refrigerant to be used.
[0019] Accordingly, the refrigerant type signal indicating the type of refrigerant to be
used, or the function necessity signal indicating the function necessity corresponding
to the type of refrigerant is transmitted from the outdoor control means to the plurality
of indoor control means. Control corresponding to the type of refrigerant indicated
by the refrigerant type signal received from the outdoor control means is performed
by the indoor control means. Additionally, control corresponding to the function indicated
by the function necessity signal is performed by the indoor control means.
[0020] As described above, the refrigerant type signal or the function necessity signal
is transmitted from the outdoor control means to the plurality of indoor control means,
and the control corresponding to the type of refrigerant indicated by the refrigerant
type signal or the control corresponding to the function indicated by the function
necessity signal is performed by the indoor control device. Thus, this configuration
allows an easy use of the plurality of indoor units in accordance with the type of
refrigerant.
[0021] In the above-described first aspect, the indoor control means may set function necessity
for coolant leakage detection according to the type of refrigerant.
[0022] According to this configuration, when a refrigerant is incombustible, the function
for coolant leakage detection is turned off, and when the refrigerant is combustible,
the function for coolant leakage detection is turned on. Thus, suitable control is
possible according to presence or absence of combustibility of the refrigerant.
[0023] In the above-described first aspect, the indoor control means may change a target
temperature of a heat exchanger included in the indoor unit according to the type
of refrigerant.
[0024] According to this configuration, since a degree of superheat during cooling operation
and a degree of subcooling during heating operation depend on characteristics of the
refrigerant, suitable control according to the type of refrigerant is possible.
[0025] In the above-described first aspect, the indoor control means may change an air flow
rate of a fan included in the indoor unit according to the type of refrigerant.
[0026] According to this configuration, since the air flow rate needed depends on the characteristics
of the refrigerant, suitable control according to the type of refrigerant is possible.
[0027] A method for controlling an air-conditioning device according to a second aspect
of the present invention is a method for controlling an air-conditioning device including
an outdoor unit, a plurality of indoor units connected with the outdoor unit via refrigerant
piping, an outdoor control means provided in the outdoor unit and configured to control
the outdoor unit, and a plurality of indoor control means provided in the respective
indoor units and configured to control the respective indoor units. In the stated
method, the outdoor control means transmits a refrigerant type signal indicating a
type of refrigerant to be used or a function necessity signal indicating function
necessity corresponding to a type of refrigerant to the plurality of indoor control
means, and the indoor control means performs control corresponding to a type of refrigerant
indicated by the refrigerant type signal received from the outdoor control means or
control corresponding to a function indicated by the function necessity signal.
Advantageous Effects of Invention
[0028] According to the present invention, an effect allowing an easy use of a plurality
of indoor units in accordance with a type of refrigerant is exhibited.
Brief Description of Drawings
[0029]
FIG. 1 is a refrigerant circuit diagram of a multi-type air-conditioning device according
to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating an electrical configuration of an outdoor control
unit and an indoor control unit according to control corresponding to a refrigerant
to be used according to the embodiment of the present invention.
FIG. 3 is a flowchart depicting a process flow according to the control corresponding
to a refrigerant to be used according to the embodiment of the present invention.
Description of Embodiments
[0030] Embodiments of an air-conditioning device and a method for controlling an air-conditioning
device according to the present invention are described below with reference to the
accompanying drawings.
[0031] In FIG. 1, a refrigerant circuit diagram of a multi-type air-conditioning device
1 according to the present embodiment is illustrated.
[0032] The multi-type air-conditioning device 1 is configured with a single outdoor unit
3, gas-side piping 5 and liquid-side piping 7 leading from the outdoor unit 3, and
a plurality of indoor units 11A and 11B connected in parallel via branching devices
9 between the gas-side piping 5 and the liquid-side piping 7.
[0033] The outdoor unit 3 includes, an inverter-driven compressor 13 configured to compress
a refrigerant, an oil separator 15 configured to separate refrigeration oil from a
refrigerant gas, a four-way selector valve 17 configured to switch a circulation direction
of the refrigerant, an outdoor heat exchanger 19 configured to cause the refrigerant
and outside air to exchange heat, a sub-cooling coil 21 formed integrally with the
outdoor heat exchanger 19, an outdoor expansion valve for heating (EEVH) 23, a receiver
25 configured to store a liquid refrigerant, a sub-cooling heat exchanger 27 configured
to provide subcooling to the liquid refrigerant, an expansion valve for sub-cooling
(EEVSC) 29 configured to control a refrigerant amount diverted to the sub-cooling
heat exchanger 27, an accumulator 31 configured to separate a liquid portion from
the refrigerant gas to be sucked into the compressor 13 and to cause the compressor
13 to suck only a gas portion, a gas-side operation valve 33, and a liquid-side operation
valve 35.
[0034] Each of the above-described devices on the outdoor unit 3 side is connected as is
well known via refrigerant piping 37 such as discharge piping 37A, gas piping 37B,
liquid piping 37C, gas piping 37D, intake piping 37E, and branching piping for sub-cooling
37F to form an outdoor coolant circuit 39.
[0035] Further, an outdoor fan 41 that blows outside air to the outdoor heat exchanger 19
is provided to the outdoor unit 3. Furthermore, an oil return circuit 43 for returning
the refrigeration oil separated from a discharged refrigerant gas in the oil separator
15 to the compressor 13 side in predetermined amounts is provided between the intake
piping 37E of the compressor 13 and the oil separator 15.
[0036] The gas-side piping 5 and the liquid-side piping 7 are the refrigerant piping 37
connected with the gas-side operation valve 33 and the liquid-side operation valve
35 of the outdoor unit 3, respectively. A length of the gas-side piping 5 is set according
to a distance between the outdoor unit 3 and the indoor unit 11A connected therewith,
and a length of the liquid-side piping 7 is set according to a distance between the
outdoor unit 3 and the indoor unit 11B connected therewith, during onsite installation
work. An appropriate number of the branching devices 9 are disposed midway on the
gas-side piping 5 and the liquid-side piping 7, and an appropriate number of the indoor
units 11A and 11B are each connected via the branching devices 9. As a result, a refrigeration
cycle 45 of one hermetically sealed system is configured.
[0037] The indoor units 11A and 11B each include an indoor heat exchanger 47 that causes
the refrigerant and inside air to exchange heat and thus performs indoor air conditioning,
an indoor expansion valve for cooling (EEVC) 49, and an indoor fan 51 that circulates
the inside air via the indoor heat exchanger 47. The indoor unit 11A is connected
with the branching devices 9 via branched gas-side piping 5A and branched liquid-side
piping 7A on the indoor side, and the indoor unit 11B is connected with the branching
devices 9 via branched gas-side piping 5B and branched liquid-side piping 7B on the
indoor side.
[0038] An outdoor control unit 53 is provided in the outdoor unit 3, and an indoor control
unit 55 is provided in each of the indoor units 11A and 11B.
[0039] Each of the outdoor control unit 53 and the indoor control unit 55 is configured
with, for example, a central processing unit (CPU), a random access memory (RAM),
a read only memory (ROM), a computer readable recording medium, and the like. Further,
for example, a sequence of processing for performing various functions is stored on
a recording medium or the like in the form of a program, and the various functions
are performed by the CPU loading this program from the recording medium, storing the
program into the RAM or the like, and executing information processing and calculation
processing. Note that the program may be preinstalled in the ROM or other recording
medium, may be provided in the form of being stored in a computer readable recording
medium, or may be distributed through wired/wireless communication means, for example.
Examples of the computer readable recording medium include a magnetic disk, a magneto-optical
disk, a CD-ROM, a DVD-ROM, a semiconductor memory, and the like.
[0040] The indoor control unit 55 is configured to transmit control information necessary
for the outdoor control unit 53 based on information inputted from a suction air temperature
sensor 63, a discharge air temperature sensor, a heat exchange temperature sensor,
a heat exchange outlet temperature sensor, and the like, and to appropriately control
a degree of opening of an indoor expansion valve 49, an air flow rate by the indoor
fan 51, or the like. Additionally, the indoor control unit 55 is configured to calculate
required capacity from a difference between an indoor temperature detected by the
suction air temperature sensor 63 and a set temperature, and to transmit the required
capacity to the outdoor control unit 53.
[0041] The outdoor control unit 53 is configured to be capable of appropriately controlling
the number of revolutions of the compressor 13, a degree of opening of the outdoor
expansion valve 23, or the like, based on control information from the indoor control
unit 55, and inputted information from an outside air temperature sensor 57, a high-pressure
sensor 59, a low-pressure sensor 61, and the like, and causing the four-way selector
valve 17 to operate in order to switch cooling and heating.
[0042] Additionally, the outdoor control unit 53 is configured to be capable of controlling
high pressure to be set to heating target high pressure (target pressure) HP during
heating operation based on detected values by the high-pressure sensor 59, and controlling
low pressure to be set to cooling target low pressure (target pressure) LP during
cooling operation based on detected values by the low-pressure sensor 61.
[0043] In the above-described multi-type air-conditioning device 1, the cooling operation
is performed as follows.
[0044] A high-temperature, high-pressure refrigerant gas compressed by the compressor 13
is discharged to the discharge piping 37A, and refrigeration oil contained in the
refrigerant is separated by the oil separator 15.
[0045] Subsequently, the refrigerant gas is circulated toward the gas piping 37B side by
the four-way selector valve 17, and subjected to heat exchange with the outside air
blown by the outdoor fan 41 to be condensed and liquefied in the outdoor heat exchanger
19.
[0046] This liquid refrigerant passes through the outdoor expansion valve 23 after being
further cooled by the sub-cooling coil 21, and is temporarily stored in the receiver
25.
[0047] Part of the liquid refrigerant whose circulation amount is adjusted by the receiver
25 is diverted to the branching piping for sub-cooling 37F in a process of circulation
through the sub-cooling heat exchanger 27 via the liquid piping 37C, is subjected
to heat exchange with the refrigerant adiabatically expanded by the expansion valve
for sub-cooling (EEVSC) 29, and is given a degree of subcooling.
[0048] This liquid refrigerant is introduced from the outdoor unit 3 to the liquid-side
piping 7 via the liquid-side operation valve 35, and the liquid refrigerant introduced
to the liquid-side piping 7 is further diverted to the branched liquid-side piping
7A and 7B of the respective indoor units 11A and 11B via the branching devices 9.
[0049] The liquid refrigerant diverted to the branched liquid-side piping 7A flows into
the indoor unit 11A and the liquid refrigerant diverted to the branched liquid-side
piping 7B flows into the indoor unit 11B. Each of the liquid refrigerants is adiabatically
expanded by the indoor expansion valve (EEVC) 49 to form a gas-liquid two-phase flow,
and is introduced into the indoor heat exchanger 47.
[0050] In the indoor heat exchanger 47, heat is exchanged between the refrigerant and the
inside air circulated by the indoor fan 51. The inside air is thus cooled and provided
for indoor cooling. On the other hand, the refrigerants are gasified, flow to the
branching device 9 via the branched gas-side piping 5A, 5B, and merge with the refrigerant
gas from other indoor unit 11 in the gas-side piping 5.
[0051] The refrigerant gas merged in the gas-side piping 5 is returned once again to the
outdoor unit 3, reaches the intake piping 37E via the gas-side operation valve 33,
the gas piping 37D, and the four-way selector valve 17, and is merged with the refrigerant
gas from the branching piping for sub-cooling 37F. The merged gas is subsequently
introduced into the accumulator 31.
[0052] In the accumulator 31, the liquid portion contained in the refrigerant gas is separated,
and only the gas portion is sucked into the compressor 13.
[0053] This refrigerant is once again compressed in the compressor 13. The cooling operation
is performed by repeating the cycle described above.
[0054] On the other hand, the heating operation is performed as follows.
[0055] A high-temperature, high-pressure refrigerant gas compressed by the compressor 13
is discharged to the discharge piping 37A, and refrigeration oil contained in the
refrigerant is separated by the oil separator 15. The refrigerant is then circulated
to the gas piping 37D side by the four-way selector valve 17.
[0056] This refrigerant is led out from the outdoor unit 3 via the gas-side operation valve
33 and the gas-side piping 5, and is further introduced into the indoor units 11A
and 11B via the branching devices 9 and the branched gas-side piping 5A and 5B on
the indoor side, respectively.
[0057] The high-temperature, high-pressure refrigerant gas introduced into either the indoor
unit 11A or 11B is subjected to heat exchange with the inside air circulated by the
indoor fan 51 in the indoor heat exchanger 47, and the inside air is thus heated and
provided for indoor heating.
[0058] The liquid refrigerant condensed in the indoor heat exchanger 47 reaches the branching
device 9 via the indoor expansion valve (EEVC) 49 and either the branched liquid-side
piping 7A or 7B, and is merged with the refrigerant from other indoor unit 11. The
merged refrigerant is subsequently returned to the outdoor unit 3 via the liquid-side
piping 7.
[0059] The refrigerant returned to the outdoor unit 3 reaches the sub-cooling heat exchanger
27 via the liquid-side operation valve 35 and the liquid piping 37C, is given subcooling
as in the case of cooling operation, is subsequently introduced into and temporarily
stored in the receiver 25, and thus a circulation amount of the refrigerant is adjusted.
[0060] This liquid refrigerant is provided to, via the liquid piping 37C, the outdoor expansion
valve (EEVH) 23, is adiabatically expanded therein, and is subsequently introduced
into the outdoor heat exchanger 19 via the sub-cooling coil 21.
[0061] In the outdoor heat exchanger 19, heat is exchanged between the refrigerant and the
outside air blown from the outdoor fan 41, and the refrigerant absorbs the heat from
the outside air and is evaporated and gasified.
[0062] This refrigerant circulates from the outdoor heat exchanger 19 via the gas piping
37B, the four-way selector valve 17, the intake piping 37E and is merged with the
refrigerant from the branching piping for sub-cooling 37F. The merged refrigerant
is subsequently introduced into the accumulator 31. In the accumulator 31, the liquid
portion contained in the refrigerant gas is separated, and only the gas portion is
sucked into the compressor 13 and once again compressed in the compressor 13. The
heating operation is performed by repeating the cycle described above.
[0063] Here, a type of the compressor 13, compressor oil, or the like needs to be changed
depending on a type of refrigerant to be used for the multi-type air-conditioning
device 1 (hereinafter referred to as a "refrigerant to be used"). Thus, specifications
of the outdoor unit 3 including the compressor 13 needs to be modified depending on
the type of refrigerant to be used. On the other hand, since main constituent elements
of the indoor unit 11 are the indoor heat exchanger 47, indoor expansion valve 49,
indoor fan 51, and the like, in a case that a refrigerant to be used is switched between
R410A and R32, for example, it is possible to share and use the indoor unit 11.
[0064] That is to say, while a hardware configuration of the outdoor unit 3 needs to be
modified according to the type of refrigerant to be used, the indoor unit 11 is capable
of supporting the refrigerant to be used without modifying a hardware configuration
thereof. However, control over the indoor unit 11 needs to be modified.
[0065] The multi-type air-conditioning device 1 according to the present embodiment performs
control corresponding to a refrigerant to be used in which control over the indoor
unit 11 is modified according to a type of refrigerant to be used.
[0066] FIG. 2 is a block diagram illustrating an electrical configuration of the outdoor
control unit 53 and the indoor control unit 55 according to the control corresponding
to a refrigerant to be used.
[0067] The outdoor control unit 53 includes a refrigerant type setting unit 60, a refrigerant
type signal generating unit 62, and a transmission unit 64.
[0068] The refrigerant type setting unit 60 is, as an example, a dip switch, and a type
of refrigerant to be used is set by switching the switch. Note that, the refrigerant
type setting unit 60 is not limited to the dip switch and, for example, may be software
in which refrigerant types are defined, and may be information stored in a storage
unit (not illustrated).
[0069] The refrigerant type signal generating unit 62 reads the type of refrigerant to be
used from the refrigerant type setting unit 60 and generates a refrigerant type signal
indicating the read type.
[0070] The transmission unit 64 transmits the refrigerant type signal to the indoor control
unit 55. Note that, the refrigerant type signal is transmitted from the transmission
unit 64 to the plurality of indoor control units 55 provided in the respective indoor
units 11 at the same time.
[0071] The indoor control unit 55 includes a reception unit 66, a control setting unit 68,
a storage unit 70, and a control unit 72.
[0072] The reception unit 66 receives the refrigerant type signal from the outdoor control
unit 53.
[0073] The control setting unit 68 sets control over the indoor unit 11 corresponding to
the type of refrigerant to be used indicated by the refrigerant type signal. Note
that, control information idicating contents of control corresponding to a type of
refrigerant to be used is stored in the storage unit 70. The control setting unit
68 reads out the contents of control corresponding to the type of refrigerant to be
used from the storage unit 70, and sets the control over the indoor unit 11 based
on the contents of control.
[0074] The control unit 72 controls the indoor unit 11 based on the contents of control
set by the control setting unit 68.
[0075] FIG. 3 is a flowchart depicting a process flow according to the control corresponding
to a refrigerant to be used according to the present embodiment. Note that, the control
corresponding to a refrigerant to be used is, for example, performed when a new multi-type
air-conditioning device 1 installed in a building or the like is operated for the
first time. Additionally, without being limited to the above-described case, the control
corresponding to a refrigerant to be used may be performed when the multi-type air-conditioning
device 1 is operated for the first time after power of the indoor unit 11 or the outdoor
unit 3 is turned on from off, a new indoor unit 11 is added, the type of refrigerant
to be used is changed, or the like.
[0076] First, in step 100, the outdoor control unit 53 reads a type of refrigerant to be
used and generates a refrigerant type signal.
[0077] In the next step 102, the outdoor control unit 53 transmits the refrigerant type
signal to the indoor control unit 55.
[0078] In the next step 104, the refrigerant type signal from the outdoor control unit 53
is received by the indoor control unit 55 of each of the indoor units 11.
[0079] As described above, in the multi-type air-conditioning device 1 in which the plurality
of indoor units 11 are connected with the single outdoor unit 3, it is appropriate
that the outdoor control unit 53 is caused to grasp the type of refrigerant to be
used, and the refrigerant type signal is transmitted to all the connected indoor control
units 55, from the viewpoint of processing efficiency.
[0080] In the next step 106, control corresponding to the type of refrigerant indicated
by the refrigerant type signal is set by the indoor control unit 55. Note that, the
set contents of control are transmitted from the indoor control unit 55 to the outdoor
control unit 53. Accordingly, since the outdoor control unit 53 is capable of grasping
the contents of control by the indoor control unit 55, the outdoor control unit 53
is capable of performing control according to the contents of control by the indoor
control unit 55, as in a case of a coolant leakage detection function described later.
[0081] In the next step 108, the indoor control unit 55 performs control according to the
refrigerant to be used based on the setting in step 106.
[0082] Next, a specific example of the contents of control corresponding to the type of
refrigerant to be used is described.
[0083] The indoor control unit 55 sets function necessity for coolant leakage detection
(hereinafter, referred to as "coolant leakage detection function") according to the
type of refrigerant to be used.
[0084] The term "coolant leakage detection function" denotes, for example, an external coolant
leakage detector, a reception function of a detection result by the coolant leakage
detector, a warning function for a user when coolant leakage is detected, or the like.
[0085] In the multi-type air-conditioning device 1, an amount of refrigerant to be used
is large, compared to an air-conditioning device in which the outdoor unit 3 and the
indoor unit 11 have a one-to-one relation. Thus, an amount of leakage becomes large
in a case of the coolant leakage. Accordingly, a safety device such as the coolant
leakage detector needs to be used suitably according to the type of refrigerant to
be used.
[0086] For example, while R410A is a non-combustible refrigerant, R32 is a slightly combustible
refrigerant. Accordingly, when the refrigerant to be used is R410A, the coolant leakage
detection function is unnecessary, and thus the function is turned off. Meanwhile,
when the refrigerant to be used is R410A, the coolant leakage detection function is
necessary, and thus the function is turned on. Accordingly, the multi-type air-conditioning
device 1 is capable of suitably controlling according to presence or absence of combustibility
of the refrigerant to be used.
[0087] Note that, when the coolant leakage detection function is turned on and the coolant
leakage detector detects coolant leakage, the outdoor control unit 53 performs so-called
pump-down operation for moving the refrigerant on the indoor unit 11 side to the outdoor
unit 3 side, and subsequently stops operation of the multi-type air-conditioning device
1. Additionally, the outdoor control unit 53 closes a valve provided on the refrigerant
piping 37 connecting the outdoor unit 3 with the indoor unit 11, or the like.
[0088] Further, the indoor control unit 55 changes a target temperature of the indoor heat
exchanger 47 included in the indoor unit 11 according to the type of refrigerant to
be used.
[0089] Since a degree of superheat during cooling operation and a degree of subcooling during
heating operation depend on characteristics of the refrigerant to be used, a degree
of superheat and a degree of subcooling are set suitably according to the type of
refrigerant to be used. Note that a target temperature corresponding to the refrigerant
to be used is stored in the storage unit 70.
[0090] Further, the indoor control unit 55 changes an air flow rate of the indoor fan 51
included in the indoor unit 11 according to the type of refrigerant to be used.
[0091] Since the air flow rate needed depends on the characteristics of the refrigerant
to be used, a suitable air flow rate corresponding to the type of refrigerant to be
used is set. Note that the air flow rate corresponding to the refrigerant to be used
is, for example, stored in the storage unit 70 as the number of revolutions of the
indoor fan 51.
[0092] As described above, the multi-type air-conditioning device 1 according to the present
embodiment includes the outdoor control unit 53 provided in the outdoor unit 3 and
configured to control the outdoor unit, and the plurality of indoor control units
55 provided in the respective indoor units 11 and configured to control the respective
indoor units 11. Additionally, the outdoor control unit 53 transmits the refrigerant
type signal indicating the type of refrigerant to be used to the plurality of indoor
control units 55. The indoor control unit 55 performs control corresponding to the
type of refrigerant to be used indicated by the refrigerant type signal received from
the outdoor control unit 53.
[0093] As described above, the refrigerant type signal is transmitted from the outdoor control
unit 53 to the plurality of indoor control units 55, and the control corresponding
to the type of refrigerant indicated by the refrigerant type signal is performed by
the indoor control unit 55. Thus, the multi-type air-conditioning device 1 according
to the present embodiment allows an easy use of the plurality of indoor units 11 connected
with the outdoor unit 3 in accordance with the type of refrigerant.
[0094] In the above, the present invention has been described using the aforementioned embodiments.
However, the technical scope of the present invention is not limited to the scope
described in the aforementioned embodiments. Various modifications or improvements
can be added to the aforementioned embodiments without deviating from the gist of
the invention, and aspects obtained by adding the modifications or improvements are
also included within the technical scope of the present invention. Also, the above-described
embodiment and the second embodiment may be combined as appropriate.
[0095] For example, the outdoor control unit 53 may transmit a function necessity signal
indicating necessity of a function corresponding to a type of refrigerant, instead
of a refrigerant type signal, to the indoor control unit 55.
[0096] A function whose necessity is indicated by the function necessity signal is, for
example, a coolant leakage detection function, but is not limited thereto, and may
be another function as long as the function needs to be changed according to a type
of refrigerant.
[0097] Determination of function necessity is performed by the outdoor control unit 53 according
to a type of refrigerant. For example, the outdoor control unit 53 stores table data
indicating necessity of functions corresponding to a type of refrigerant, and refers
to the table data to determine function necessity every time a type of refrigerant
is set.
[0098] Note that, without being limited to the above-described case, an administrator of
the multi-type air-conditioning device 1 may input information indicating function
necessity corresponding to a type of refrigerant to the outdoor control unit 53. The
outdoor control unit 53 may transmit a function necessity signal to the indoor control
unit 55 based on the inputted information.
[0099] Additionally, control corresponding to the function indicated by the received function
necessity signal is performed by the indoor control unit 55.
[0100] More specifically, the indoor control unit 55 starts performing a function needed
by the function necessity signal unless the function is performed. In a case that
a function not needed by the function necessity signal is being performed, the indoor
control unit 55 stops performing the function. On the other hand, in a case that the
function needed by the function necessity signal is being performed, the indoor control
unit 55 continues to perform the function.
[0101] Furthermore, the flow of the control corresponding to a refrigerant to be used described
in the aforementioned embodiments is also an example, and an unnecessary step may
be deleted, a new step may be added, and the processing order may be changed without
deviating from the gist of the present invention.
Reference Signs List
[0102]
1 Multi-type air-conditioning device (Air-conditioning device)
3 Outdoor unit
11 Indoor unit
37 Refrigerant piping
53 Outdoor control unit (Outdoor control means)
55 Indoor control unit (Indoor control means)