GB2567332A - Air conditioning device - Google Patents
Air conditioning device Download PDFInfo
- Publication number
- GB2567332A GB2567332A GB1819447.2A GB201819447A GB2567332A GB 2567332 A GB2567332 A GB 2567332A GB 201819447 A GB201819447 A GB 201819447A GB 2567332 A GB2567332 A GB 2567332A
- Authority
- GB
- United Kingdom
- Prior art keywords
- refrigerant
- solenoid valves
- flow rate
- cooling
- unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004378 air conditioning Methods 0.000 title claims abstract description 85
- 238000010438 heat treatment Methods 0.000 claims abstract description 205
- 239000007788 liquid Substances 0.000 claims abstract description 152
- 238000000926 separation method Methods 0.000 claims abstract description 36
- 238000010257 thawing Methods 0.000 claims abstract description 31
- 239000003507 refrigerant Substances 0.000 claims description 336
- 238000001816 cooling Methods 0.000 claims description 289
- 238000001514 detection method Methods 0.000 abstract description 79
- 239000002826 coolant Substances 0.000 abstract description 10
- 239000007789 gas Substances 0.000 description 68
- 230000004048 modification Effects 0.000 description 21
- 238000012986 modification Methods 0.000 description 21
- 238000010586 diagram Methods 0.000 description 18
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 8
- 230000003247 decreasing effect Effects 0.000 description 7
- 206010037660 Pyrexia Diseases 0.000 description 4
- 229910002092 carbon dioxide Inorganic materials 0.000 description 4
- 239000001569 carbon dioxide Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 238000005057 refrigeration Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- -1 that is Chemical compound 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B29/00—Combined heating and refrigeration systems, e.g. operating alternately or simultaneously
- F25B29/003—Combined heating and refrigeration systems, e.g. operating alternately or simultaneously of the compression type system
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B13/00—Compression machines, plants or systems, with reversible cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
- F25B41/24—Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
- F25B47/022—Defrosting cycles hot gas defrosting
- F25B47/025—Defrosting cycles hot gas defrosting by reversing the cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
- F25B2313/0231—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with simultaneous cooling and heating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
- F25B2313/0233—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/025—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units
- F25B2313/0253—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units in parallel arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/031—Sensor arrangements
- F25B2313/0311—Pressure sensors near the expansion valve
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/031—Sensor arrangements
- F25B2313/0314—Temperature sensors near the indoor heat exchanger
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/23—Separators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2509—Economiser valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2513—Expansion valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2519—On-off valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/19—Pressures
- F25B2700/193—Pressures of the compressor
- F25B2700/1931—Discharge pressures
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/19—Pressures
- F25B2700/193—Pressures of the compressor
- F25B2700/1933—Suction pressures
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
- Air Conditioning Control Device (AREA)
Abstract
Provided is an air conditioning device comprising a heat source, a plurality of indoor units, a relay device, and a control unit. The relay device has a liquid state detection unit, a gas/liquid separation device, a second flow rate control device, a third flow rate control device, a cooler solenoid valve, and a heater solenoid valve. The control unit has the following: a valve control means that, when the heat source switches from heating operation to defrosting operation, causes a flow path switching valve to switch, stops the heater solenoid valve, and opens the second flow rate control device; a determination means that determines whether the coolant flowing in the second flow rate control device or the third flow rate control device is generating flow noise on the basis of the state of the coolant detected by the liquid state detection unit when the coolant flows in the second flow rate control device; and a timing control means that controls the valve control means such that the heater solenoid valve and the cooler solenoid valve successively open when the determination means determines that the coolant flowing in the second flow rate control device or the third flow rate control device is generating flow noise.
Description
Other: Jitsuyo Shinan Koho 1922-1996; Jitsuyo Shinan Toroku Koho 1996-2016; Kokai Jitsuyo Shinan Koho 1971-2016; Toroku Jitsuyo Shinan Koho 1994-2016 (54) Title of the Invention: Air conditioning device
Abstract Title: Air conditioning device (57) Provided is an air conditioning device comprising a heat source, a plurality of indoor units, a relay device, and a control unit. The relay device has a liquid state detection unit, a gas/liquid separation device, a second flow rate control device, a third flow rate control device, a cooler solenoid valve, and a heater solenoid valve. The control unit has the following: a valve control means that, when the heat source switches from heating operation to defrosting operation, causes a flow path switching valve to switch, stops the heater solenoid valve, and opens the second flow rate control device; a determination means that determines whether the coolant flowing in the second flow rate control device or the third flow rate control device is generating flow noise on the basis of the state of the coolant detected by the liquid state detection unit when the coolant flows in the second flow rate control device; and a timing control means that controls the valve control means such that the heater solenoid valve and the cooler solenoid valve successively open when the determination means determines that the coolant flowing in the second flow rate control device or the third flow rate control device is generating flow noise.
open third flow rate control device 15
ST200 Determine whether operation to suppress coolant noise Is necessary (second flow rate control device 13, third flow rate control device 15)
ST300 Open heater solenoid valve 30
ST400 Determine whether operation to suppress coolant noise is necessary (heater solenoid valve 30)
ST500 Close heater solenoid valve 30, open cooler solenoid
STS00 Has time threshold elapsed?
ST700 Open heater solenoid valve 30
AA Start defrosting operation
BB Continue control
1/12
100
2/12
FIG. 2
100
CONFLUENT PRESSURE DETECTION SENSOR
LIQUID OUTFLOW PRESSURE DETECTION Π SENSOR
X
T~
DOWNSTREAM
LIQUID OUTFLOW!... PRESSURE DETECTION SENSOR
FIRST FLOW RATE CONTROL DEVICE
VALVE CONTROL UNIT ’ DETERH MINATION UNIT
SECOND FLOW RATE CONTROL DEVICE
THIRD FLOW M RATE CONTROL DEVICE x>15
HEATING SOLENOID VALVES
A-' 30
TIMING CONTROL UNIT )
INDOOR UNITS
FIRST COOLING SOLENOID VALVES
SECOND COOLING SOLENOID VALVES
V'31a
-31b
3/12
FIG. 3
4/12
FIG. 4
5/12
FIG. 5
6/12
FIG. 6
7/12
FIG. 7
8/12
FIG. 8
52b
9/12
FIG. 9
10/12
FIG. 10 f REFRIGERANT NOISE 5 (REDUCTION OPERATION START)
Yes
SELECT SECOND COOLING SOLENOID VALVE 31bj^ , CONNECTED TO INDOOR UNIT OF LOW ADDRESS
DETERM NE
NECESS TY OF REFR GERAT ON NO SE REDUCT ON OPERATION (RE-CHECK)
OPEN T ME
THRESHOLD PASSED S NCE
OPEN NG OTHER SECOND
COOL NG SOLENO D
VALVE 31b?
OPEN SELECTED SECOND COOLING SOLENOID VALVE 31b
11/12
FIG. 11
FIG. 12
T T T T T T
FIG. 13
REFRIGERANT NOISE REDUCTION OPERATION
NORMAL OPERATION □ FFERENT AL
PRESSURE APa ACROSS
COOL NG SOLENO D VALVES
ΔΡα?
REFRIGERATION NOISE REDUCTION OPERATION NECESSITY DETERMINATION (RE-CHECK)
ST41
J
12/12
FIG. 14 /'REFRIGERATION NOISE REDUCTION OPERATION NECESSITY
V DETERMINATION (RE-CHECK)
FIG. 15
DESCRIPTION
Title of Invention
AIR CONDITIONING APPARATUS
Technical Field [0001]
The present invention relates to an air conditioning apparatus including a relay unit that distributes refrigerant supplied from a heat source unit to multiple indoor units.
Background Art [0002]
An air conditioning apparatus where heating operation or cooling operation is performed individually in multiple indoor units is provided with a refrigerant circuit and structure whereby heating energy, cooling energy, or both heating energy and cooling energy created in a heat source unit are supplied to multiple loads efficiently, for example. Such an air conditioning apparatus is applied to a multi-air-conditioning system for a building or other facilities, for example. Heretofore, in an air conditioning apparatus such as a multi-air-conditioning system for a building, heating operation or cooling operation is executed by circulating refrigerant between an outdoor unit disposed outdoors that acts as a heat source unit and indoor units disposed indoors. Specifically, the cooling or heating of an air-conditioned space is performed using air that has been cooled due to a refrigerant removing heat, or air that has been heated due to a refrigerant rejecting heat. For example, HFC refrigerants, that is, hydrofluorocarbon refrigerants, are often used as the refrigerant in such an air conditioning apparatus. Also, air conditioning apparatus in which a natural refrigerant such as carbon dioxide, that is, CO2, is used have been proposed. [0003]
At this point, an air conditioning apparatus has been proposed in which a heat source unit is connected to multiple indoor units, refrigerant is supplied from the heat source unit to the multiple indoor units, and simultaneous cooling and heating operation is performed. The air conditioning apparatus described in Patent
Literature 1 is provided with a first connecting pipe, a first branching unit including a three-way switching valve that connects to the first connecting pipe or a second connecting pipe so that it can be switched, and a second branching unit that connects the second connecting pipe and the second connecting pipe on the indoor unit side via six check valves.
[0004]
The air conditioning apparatus described in Patent Literature 1 switches the refrigerant flowing into an indoor unit performing heating operation and the refrigerant flowing in from an indoor unit performing cooling operation in the three-way switching valve of the first branching unit. Also, each check valve included in the second branching unit allows a unidirectional circulation of refrigerant according to the switching of refrigerant in the first branching unit. For this reason, in the case where an indoor unit performs cooling operation, among the connecting ports of the threeway switching valve, a first port is closed, while a second port and a third port are opened. Also, in the case where an indoor unit performs heating operation, among the connecting ports, the second port is closed, while the first port and the third port are opened.
[0005]
Additionally, in the case where an indoor unit performs cooling operation, since the first connecting pipe is low pressure and the second connecting pipe is high pressure, among the connecting ports of the three-way switching valve, the refrigerant is brought into a high-pressure state in the connecting pipe on the side of the first port, a low-pressure state in the connecting pipe on the side of the second port, and a low-pressure state in the connecting pipe on the side of the third port. Also, during cooling operation, the refrigerant is controlled by the amount of superheating on the outlet side of an indoor heat exchanger, and refrigerant in a lowpressure gas state flows through the first connecting pipe on the indoor unit side. [0006]
Also, in the case where an indoor unit performs heating operation, since the first connecting pipe is low pressure and the second connecting pipe is high pressure, among the connecting ports of the three-way switching valve, the refrigerant is brought into a high-pressure state in the connecting pipe on the side of the first port, a low-pressure state in the connecting pipe on the side of the second port, and a highpressure state in the connecting pipe on the side of the third port. Also, during heating operation, the refrigerant is controlled by the amount of sub-cooling on the outlet side of an indoor heat exchanger, and refrigerant in a high-temperature highpressure gas state flows through the first connecting pipe on the indoor unit side. At this point, refrigerant in a high-temperature high-pressure liquid state exists in an indoor heat exchanger and the connecting pipe from the indoor heat exchanger to a first flow rate control apparatus.
[0007]
Therefore, when switching the operation of an indoor unit from heating operation to cooling operation, the high-temperature high-pressure gas refrigerant and the high-temperature high-pressure liquid refrigerant that were flowing during heating pass through the three-way switching valve and flow into the first connecting pipe in a low-pressure state. At this time, in the three-way switching valve, flow noise of the refrigerant is generated due to the balance of high pressure and low pressure in the refrigerant passing through the three-way switching valve. Particularly, the flow noise of the high-temperature high-pressure liquid refrigerant becomes loud.
[0008]
For this reason, an air conditioning apparatus that uses solenoid valves, particularly solenoid opening and closing valves, instead of a three-way switching valve has been proposed. In the air conditioning apparatus described in Patent Literature 2, a second solenoid valve is used for heating while a first solenoid valve and a third solenoid valve with an added orifice function are used for cooling, such that when switching from heating operation to cooling operation, refrigerant flows in stages in the first solenoid valve and the third solenoid valve. This configuration is aimed at reducing the flow noise of the high-temperature high-pressure refrigerant. Also, in the air conditioning apparatus described in Patent Literature 2, the opening diameter of the flow rate control apparatus is decreased, the flow rate control apparatus is pulse-controlled, and the opening diameter of the third solenoid valve is decreased in an attempt to reduce the flow noise of the refrigerant. Additionally, in an attempt to make the apparatus more compact, an air conditioning apparatus that uses solenoid valves, particularly solenoid opening and closing valves, has been proposed. In the air conditioning apparatus, a second solenoid valve is used for heating, while a first solenoid valve, a third solenoid valve, and an orifice are used for cooling. Herein, the orifice serves to reduce the flow noise of refrigerant by bypassing high-pressure pressure and low-pressure pressure to equalize the pressure between a high-pressure side pipe and a low-pressure side pipe. In other words, in this air conditioning apparatus, when switching from heating operation to cooling operation, refrigerant flows in stages in the orifice, the third solenoid valve, and the first solenoid valve. This configuration is aimed at reducing the flow noise of the high-temperature high-pressure refrigerant. Additionally, in air conditioning apparatus of the related art, in the case of switching from heating operation to defrosting operation, after refrigerant flows in from a heat source unit to a relay unit, the refrigerant flows out to a liquid outflow side of a gas-liquid separation apparatus, passes through a bypass circuit, and returns to the heat source unit. At this time, after the refrigerant flows out to the liquid outflow side of the gas-liquid separation apparatus, the refrigerant flows sequentially through a first heat exchange unit, a flow rate control apparatus, a second heat exchange unit, the flow rate control apparatus, the second heat exchange unit, and the first heat exchange unit.
Citation List
Patent Literature [0009]
Patent Literature 1: Japanese Patent No. 4350836
Patent Literature 2: Japanese Unexamined Patent Application Publication No. H09-042804
Summary of Invention
Technical Problem [0010]
However, an air conditioning apparatus of the related art involves a risk that, during defrosting operation, refrigerant flowing through the flow rate control apparatus on the liquid outflow side of the gas-liquid separation apparatus will generate flow noise.
[0011]
The present invention has been attained to solve problems mentioned above, and provides an air conditioning apparatus that, during defrosting operation, minimizes the generation of flow noise by refrigerant in the flow rate control apparatus on the liquid outflow side of the gas-liquid separation apparatus.
Solution to Problem [0012]
An air conditioning apparatus according to an embodiment of the present invention is provided with: a heat source unit including a compressor, a channel switching valve, and a heat source side heat exchanger; a plurality of indoor units that perform a cooling operation or a heating operation, with each indoor unit including a first flow rate control apparatus and an indoor side heat exchanger; a relay unit, connected to the heat source unit by a first connecting pipe and a second connecting pipe, and connected to each of the plurality of indoor units by a plurality of gas branch pipes and a plurality of liquid branch pipes, that distributes a refrigerant supplied from the heat source unit to the plurality of indoor units; and a controller configured to control an operation of the relay unit, wherein the relay unit includes a liquid state detector that detects a state of refrigerant flowing between the liquid branch pipes and the second connecting pipe, a gas-liquid separation apparatus that separates inflowing refrigerant into gas refrigerant and liquid refrigerant, having an inflow side connected to the second connecting pipe, a gas outflow side connected to the gas branch pipes, and a liquid outflow side connected to the liquid branch pipes and the first connecting pipe, a second flow rate control apparatus that is provided on the liquid outflow side of the gas-liquid separation apparatus, closed during the heating operation, open during the cooling operation, and adjusts a flow rate of the refrigerant, a third flow rate control apparatus that is provided on a downstream side of the second flow rate control apparatus and adjusts a flow rate of the refrigerant, cooling solenoid valves that are open during the cooling operation and closed during the heating operation, having one end being connected to the gas branch pipes and the other end being connected to the first connecting pipe, heating solenoid valves that are open during the heating operation and closed during the cooling operation, having one end being connected to the gas branch pipes and the other end being connected to the gas outflow side of the gas-liquid separation apparatus, and the controller includes a valve control unit that, when the heat source unit is switched from the heating operation to a defrosting operation, switches the channel switching valve, closes the heating solenoid valves, and opens the second flow rate control apparatus, a determination unit that, when refrigerant is circulated through the second flow rate control apparatus, determines whether or not the refrigerant flowing through the second flow rate control apparatus or the third flow rate control apparatus is generating a flow noise, based on the state of the refrigerant detected by the liquid state detector, and a timing control unit that, in a case where the determination unit determines that the refrigerant flowing through the second flow rate control apparatus or the third flow rate control apparatus is generating the flow noise, controls the valve control unit to successively open the heating solenoid valves and the cooling solenoid valves.
Advantageous Effects of Invention [0013]
According to the present invention, during defrosting operation, in a case of determining whether flow noise has generated in refrigerant flowing through the second flow rate control apparatus or the third flow rate control apparatus, the heating solenoid valves and the cooling solenoid valves are opened successively. With this arrangement, since the amount of refrigerant flowing through the second flow rate control apparatus or the third flow rate control apparatus is decreased, generation of flow noise by the refrigerant flowing through the second flow rate control apparatus or the third flow rate control apparatus is minimized. Consequently, quiet operation of the air conditioning apparatus is realized.
Brief Description of Drawings [0014] [Fig. 1] Fig. 1 is a circuit diagram illustrating an air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 2] Fig. 2 is a block diagram illustrating a controller 70 of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 3] Fig. 3 is a circuit diagram illustrating a state during cooling only operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 4] Fig. 4 is a circuit diagram illustrating a state during heating only operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 5] Fig. 5 is a circuit diagram illustrating a state during cooling main operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 6] Fig. 6 is a circuit diagram illustrating a state during heating main operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 7] Fig. 7 is a circuit diagram illustrating a first state during defrosting operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 8] Fig. 8 is a circuit diagram illustrating a second state during defrosting operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 9] Fig. 9 is a flowchart illustrating operations of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 10] Fig. 10 is a flowchart illustrating operations of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 11] Fig. 11 is a flowchart illustrating operations of the air conditioning apparatus 100 according to Embodiment 1 of the present invention.
[Fig. 12] Fig. 12 is a circuit diagram illustrating an air conditioning apparatus 200 of the related art.
[Fig. 13] Fig. 13 is a flowchart illustrating operations of the air conditioning apparatus 100 according to a first modification of Embodiment 1 of the present invention.
[Fig. 14] Fig. 14 is a flowchart illustrating operations of the air conditioning apparatus 100 according to a second modification of Embodiment 1 of the present invention.
[Fig. 15] Fig. 15 is a flowchart illustrating operations of the air conditioning apparatus 100 according to a third modification of Embodiment 1 of the present invention.
Description of Embodiments [0015]
Embodiment 1
Hereinafter, Embodiment 1 of an air conditioning apparatus according to the present invention will be described with reference to the drawings. Fig. 1 is a circuit diagram illustrating the air conditioning apparatus 100 according to Embodiment 1 of the present invention. The air conditioning apparatus 100 will be described on the basis of Fig. 1. As illustrated in Fig. 1, the air conditioning apparatus 100 is provided with a heat source unit A, multiple indoor units B, C, and D, a relay unit E, and a controller 70. Note that in Embodiment 1, the case where three indoor units B, C, and D are connected to a single heat source unit A is illustrated by example, but there may also be two or more heat source units A. Additionally, there may also be three or more indoor units.
[0016]
As illustrated in Fig. 1, the air conditioning apparatus 100 is configured such that the heat source unit A, the indoor units B, C, and D, and the relay unit E are connected. The heat source unit A includes a function of supplying heating energy or cooling energy to the three indoor units B, C, and D. The three indoor units B, C, and D are connected to in parallel with each other, and each has the same configuration. The indoor units B, C, and D include a function of cooling or heating an air-conditioned space such as a room with heating energy or cooling energy supplied from the heat source unit A. The relay unit E is interposed between the heat source unit A and the indoor units B, C, and D, and includes a function of switching the flow of refrigerant supplied from the heat source unit A according to demand issued from the indoor units B, C, and D. In addition, the air conditioning apparatus 100 is provided with a liquid state detector 81 and a gas state detector 80 that detect the state of refrigerant. The liquid state detector 81 includes a liquid outflow pressure detection sensor 25 and a downstream liquid outflow pressure detection sensor 26, for example. Also, the gas state detector 80 includes a confluent pressure detection sensor 56. Note that the gas state detector 80 may also include a gas pipe temperature detection sensor 53, a liquid pipe temperature detection sensor 54, the liquid outflow pressure detection sensor 25, the downstream liquid outflow pressure detection sensor 26, a confluent pressure detection sensor 56, and a discharge pressure detection sensor 18.
[0017] (Heat source unit A)
The heat source unit A is provided with a variable-capacity compressor 1, a channel switching valve 2 that switches the refrigerant circulation direction in the heat source unit A, a heat source side heat exchange unit 3 that functions as an evaporator or a condenser, an accumulator 4 connected to the suction side of the compressor 1 via the channel switching valve 2, and a heat source side channel adjustment unit 40 that restricts the circulation direction of refrigerant. The heat source unit A includes a function of supplying heating energy or cooling energy to the indoor units B, C, and D. Note that the channel switching valve 2 is illustrated as being a four-way valve by way of example, but may also be configured by combining two-way valves, three-way valves, or other types of valves.
[0018]
The heat source side heat exchange unit 3 is provided with a first heat source side heat exchanger 41 and a second heat source side heat exchanger 42, a heat source side bypass channel 43, a first solenoid opening and closing valve 44, a second solenoid opening and closing valve 45, a third solenoid opening and closing valve 46, a fourth solenoid opening and closing valve 47, a fifth solenoid opening and closing valve 48, and a heat source side fan 20.
[0019]
The first heat source side heat exchanger 41 and the second heat source side heat exchanger 42 have the same heat transfer area, and are connected in parallel with each other. The heat source side bypass channel 43 is connected in parallel to the first heat source side heat exchanger 41 and the second heat source side heat exchanger 42. Refrigerant circulating through the heat source side bypass channel 43 does not pass through the first heat source side heat exchanger 41 and the second heat source side heat exchanger 42, and does not undergo heat exchange. [0020]
The first solenoid opening and closing valve 44 is provided on one end of the first heat source side heat exchanger 41. The second solenoid opening and closing valve 45 is provided on the other end of the first heat source side heat exchanger 41. The third solenoid opening and closing valve 46 is provided on one end of the second heat source side heat exchanger 42. The fourth solenoid opening and closing valve 47 is provided on the other end of the second heat source side heat exchanger 42. The fifth solenoid opening and closing valve 48 is provided in the heat source side bypass channel 43.
[0021]
The heat source side channel adjustment unit 40 includes a third check valve 32, a fourth check valve 33, a fifth check valve 34, and a sixth check valve 35. The third check valve 32 is provided in a pipe that connects the heat source side heat exchange unit 3 and a second connecting pipe 7, and allows the circulation of refrigerant from the heat source side heat exchange unit 3 towards the second connecting pipe 7. The fourth check valve 33 is provided in a pipe that connects the channel switching valve 2 of the heat source unit A and a first connecting pipe 6, and allows the circulation of refrigerant from the first connecting pipe 6 towards the channel switching valve 2. The fifth check valve 34 is provided in a pipe that connects the channel switching valve 2 of the heat source unit A and the second connecting pipe 7, and allows the circulation of refrigerant from the channel switching valve 2 towards the second connecting pipe 7. The sixth check valve 35 is provided in a pipe that connects the heat source side heat exchange unit 3 and the first connecting pipe 6, and allows the circulation of refrigerant from the first connecting pipe 6 towards the heat source side heat exchange unit 3.
[0022]
Also, in the heat source unit A, the discharge pressure detection sensor 18 is provided. The discharge pressure detection sensor 18 is provided in a pipe that connects the channel switching valve 2 and the discharge side of the compressor 1, and detects the discharge pressure of the compressor 1. The heat source side fan 20 varies the airflow volume of air sent to the heat source side heat exchange unit 3, and controls the volume of heat exchange. Note that in a case where the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42 becomes frosted during heating operation, the heat source unit A executes defrosting operation.
[0023] (Indoor units B, C, and D)
The indoor units B, C, and D are provided with an indoor side heat exchanger 5 that functions as a condenser or an evaporator as well as a first flow rate control apparatus 9, and include a function of cooling or heating an air-conditioned space such as a room with heating energy or cooling energy supplied from the heat source unit A. During cooling, the first flow rate control apparatus 9 is controlled by the amount of superheating on the outlet side of the indoor side heat exchanger 5. Also, during heating, the first flow rate control apparatus 9 is controlled by the amount of sub-cooling on the outlet side of the indoor side heat exchanger 5.
[0024]
In the indoor units B, C, and D, the gas pipe temperature detection sensor 53 and the liquid pipe temperature detection sensor 54 are provided. The gas pipe temperature detection sensor 53 is provided between each indoor side heat exchanger 5 and the relay unit E, and detects the temperature of refrigerant circulating in gas branch pipes 6b, 6c, and 6d that connect each indoor side heat exchanger 5 and the relay unit E. The liquid pipe temperature detection sensor 54 is provided between each indoor side heat exchanger 5 and the first flow rate control apparatus 9, and detects the temperature of refrigerant circulating in liquid branch pipes 7b, 7c, and 7d that connect each indoor side heat exchanger 5 and the first flow rate control apparatus 9.
[0025] (Relay unit E)
The relay unit E is provided with a first branching unit 10, a second flow rate control apparatus 13, a second branching unit 11, a gas-liquid separation apparatus 12, a heat exchange unit 8, and a third flow rate control apparatus 15. The relay unit E is interposed between the heat source unit A and the indoor units B, C, and D, switches the flow of refrigerant supplied from the heat source unit A according to demand issued from the indoor units B, C, and D, and includes a function of distributing refrigerant supplied from the heat source unit A to the multiple indoor units B, C, and D.
[0026]
Herein, the channel switching valve 2 of the heat source unit A and the relay unit E are connected by the first connecting pipe 6. The indoor side heat exchangers 5 of the indoor units B, C, and D are connected to the relay unit E by the gas branch pipes 6b, 6c, and 6d on the side of the indoor units B, C, and D corresponding to the first connecting pipe 6. The heat source side heat exchange unit 3 of the heat source unit A and the relay unit E are connected by the second connecting pipe 7 having a smaller diameter than the first connecting pipe 6. The indoor side heat exchangers 5 of the indoor units B, C, and D are connected to the relay unit E via the first connecting pipe 6, and also by the liquid branch pipes 7b, 7c, and 7d on the side of the indoor units B, C, and D corresponding to the second connecting pipe 7.
[0027]
One end of the first branching unit 10 is connected to the gas branch pipes 6b, 6c, and 6d while the other end is connected to the first connecting pipe 6 and the second connecting pipe 7, whereby the circulation direction of refrigerant during cooling operation and the circulation direction of refrigerant during heating operation are different. The first branching unit 10 is provided with first cooling solenoid valves 31a, second cooling solenoid valves 31b, and heating solenoid valves 30. The first cooling solenoid valves 31a and the second cooling solenoid valves 31b are connected in parallel with each other, with one end of each being connected to the gas branch pipes 6b, 6c, and 6d while the other end of each is connected to the first connecting pipe 6, being opened during cooling operation and closed during heating operation. Note that the first cooling solenoid valves 31a, the second cooling solenoid valves 31b, and the heating solenoid valves 30 are not limited to a certain type of valve, and may also be motor-operated valves, for example.
[0028]
Additionally, one end of the heating solenoid valves 30 is connected to the gas branch pipes 6b, 6c, and 6d while the other end is connected to the second connecting pipe 7, being opened during heating operation and closed during cooling operation. Note that in the following, the first cooling solenoid valves 31 a and the second cooling solenoid valves 31b connected to the indoor units B, C, and D will be collectively designated the cooling solenoid valves 31 in some cases. The cooling solenoid valves 31 are not limited to two, and three or more may also be provided. Also, the Cv values of the first cooling solenoid valves 31a and the second cooling solenoid valves 31 b may be the same or different. Furthermore, the Cv values of the cooling solenoid valves 31 connected to each of the indoor units B, C, and D may be the same or different.
[0029]
One end of the second branching unit 11 is connected to the liquid branch pipes 7b, 7c, and 7d while the other end is connected to the first connecting pipe 6 and the second connecting pipe 7, whereby the circulation direction of refrigerant during cooling operation and the circulation direction of refrigerant during heating operation are different. The second branching unit 11 includes first check valves 50b, 50c, and 50d, and second check valves 52b, 52c, and 52d.
[0030]
The first check valves 50b, 50c, and 50d are provided in equal number corresponding to the number of the indoor units B, C, and D. The first check valves 50b, 50c, and 50d are provided in the liquid branch pipes 7b, 7c, and 7d, respectively, and allow the circulation of refrigerant from the second connecting pipe 7 towards the liquid branch pipes 7b, 7c, and 7d.
[0031]
The second checkvalves 52b, 52c, and 52d are provided in equal number corresponding to the number of the indoor units B, C, and D. The second check valves 52b, 52c, and 52d are connected to the first check valves 50b, 50c, and 50d in parallel in the liquid branch pipes 7b, 7c, and 7d, respectively, and allow the circulation of refrigerant from the liquid branch pipes 7b, 7c, and 7d towards the second connecting pipe 7.
[0032]
The gas-liquid separation apparatus 12 separates refrigerant in the gas state from refrigerant in the liquid state, with the inflow side being connected to the second connecting pipe 7, the gas outflow side being connected to the first branching unit 10, and the liquid outflow side being connected to the second branching unit 11. [0033]
The heat exchange unit 8 includes a first heat exchange unit 19 and a second heat exchange unit 16. The second flow rate control apparatus 13 includes an electric expansion valve or other valve that can be opened and closed, for example. The second flow rate control apparatus 13 is closed during heating operation and opened during cooling operation. Herein, the gas-liquid separation apparatus 12 and the second branching unit 11 are connected through the first heat exchange unit 19, the second flow rate control apparatus 13, and the second heat exchange unit 16. Also, the second branching unit 11 and the first connecting pipe 6 are connected by a first bypass pipe 14. The third flow rate control apparatus 15 is provided in the first bypass pipe 14 on the downstream side of the second flow rate control apparatus 13, and includes an electric expansion valve or other valve that can be opened and closed, for example. Herein, the second branching unit 11 and the first connecting pipe 6 are connected through the third flow rate control apparatus 15, the second heat exchange unit 16, and the first heat exchange unit 19.
[0034]
In other words, the first heat exchange unit 19 exchanges heat between the upstream side of the second flow rate control apparatus 13 in the second connecting pipe 7 and the downstream side of the second heat exchange unit 16 in the first bypass pipe 14. Also, the second heat exchange unit 16 exchanges heat between the downstream side of the second flow rate control apparatus 13 in the second connecting pipe 7 and the upstream side of the third flow rate control apparatus 15 in the first bypass pipe 14. In this way, the gas outflow side of the gas-liquid separation apparatus 12 is connected to the heating solenoid valves 30, while the liquid outflow side is connected to the liquid branch pipes 7b, 7c, and 7d and the first connecting pipe 6.
[0035]
Note that the downstream side of the first check valves 50b, 50c, and 50d in the liquid branch pipes 7b, 7c, and 7d, the downstream side of the second flow rate control apparatus 13 in the second connecting pipe 7, and the upstream side of the second heat exchange unit 16 are connected by a second bypass pipe 51. Additionally, pipes connected to the liquid branch pipes 7b, 7c, and 7d in the second bypass pipe 51 and a pipe connected to the second connecting pipe 7 in the second bypass pipe 51 converge along the way.
[0036]
Also, the second check valves 52b, 52c, and 52d are provided upstream of the portion where the pipes connected to the liquid branch pipes 7b, 7c, and 7d in the second bypass pipe 51 and the pipe connected to the second connecting pipe 7 in the second bypass pipe 51 converge. Note that the channel leading from the second connecting pipe 7 through the liquid branch pipes 7b, 7c, and 7d provided with the first check valves 50b, 50c, and 50d up to the first flow rate control apparatus 9 forms a first refrigerant channel, while the channel leading from the first flow rate control apparatus 9 through the second bypass pipe 51 provided with the liquid branch pipes 7b, 7c, and 7d and the second check valves 52b, 52c, and 52d up to the second connecting pipe 7 forms a second refrigerant channel.
[0037]
Also, in the relay unit E, the liquid outflow pressure detection sensor 25, the downstream liquid outflow pressure detection sensor 26, and the confluent pressure detection sensor 56 are provided. The liquid outflow pressure detection sensor 25 is provided between the first heat exchange unit 19 and the second flow rate control apparatus 13 in the second connecting pipe 7, and detects the pressure of refrigerant on the liquid outflow side of the gas-liquid separation apparatus 12. The downstream liquid outflow pressure detection sensor 26 is provided between the second flow rate control apparatus 13 and the second heat exchange unit 16 in the second connecting pipe 7, and detects the pressure of refrigerant between the second flow rate control apparatus 13 and the second heat exchange unit 16. In other words, the downstream liquid outflow pressure detection sensor 26 detects the pressure of refrigerant circulating through the portion where the multiple liquid branch pipes 7b, 7c, and 7d converge. The confluent pressure detection sensor 56 is provided in the portion where the first connecting pipe 6 and the first bypass pipe 14 are connected, and detects the pressure of refrigerant circulating through the portion where the liquid branch pipes 7b, 7c, and 7d and the first connecting pipe 6 are connected.
[0038] (Refrigerant)
In the air conditioning apparatus 100, pipes are filled with refrigerant. For the refrigerant, for example, natural refrigerants such as carbon dioxide (CO2), hydrocarbon, and helium, non-chlorine-containing CFC substitutes such as HFC410A, HFC407C, and HFC404A, and CFC refrigerants such as R22 and R134a used in existing products, or another type of refrigerant is used. Note that HFC407C is a non-azeotropic refrigerant mixture in which HFC R32, R125, and R134a are mixed in amount ratios 23 wt%, 25 wt%, and 52 wt%, respectively. Additionally, the pipes of the air conditioning apparatus 100 may also be filled with heat medium rather than refrigerant. The heat medium is a medium such as water or brine, for example. [0039] (Controller 70)
The controller 70 controls the overall system of the air conditioning apparatus 100. Specifically, on the basis of instructions from detection information received from the gas pipe temperature detection sensors 53, the liquid pipe temperature detection sensors 54, the liquid outflow pressure detection sensor 25, the downstream liquid outflow pressure detection sensor 26, the confluent pressure detection sensor 56, and the discharge pressure detection sensor 18 as well as from a remote control (not illustrated), the controller 70 controls the driving frequency of the compressor 1, the rotation rate of the heat source side fan 20 and fans (not illustrated) provided in the indoor side heat exchangers 5, the switching of the channel switching valve 2, the opening and closing of the first solenoid opening and closing valve 44, the second solenoid opening and closing valve 45, the third solenoid opening and closing valve 46, the fourth solenoid opening and closing valve 47, the fifth solenoid opening and closing valve 48, the first cooling solenoid valves 31a, the second cooling solenoid valves 31b, and the heating solenoid valves 30, the opening degree of the first flow rate control apparatus 9, the second flow rate control apparatus 13, and the third flow rate control apparatus 15, and other components. [0040]
Note that the controller 70 may be installed in any or all of the heat source unit A, the indoor units B, C, and D, and the relay unit E. Additionally, the controller 70 may also be installed apart from the heat source unit A, the indoor units B, C, and D, and the relay unit E. In addition, in the case where the air conditioning apparatus 100 includes multiple controllers 70, the multiple controllers 70 are communicably connected to each other in a wired or wireless manner.
[0041]
Fig. 2 is a block diagram illustrating the controller 70 of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. As illustrated in Fig. 2, the controller 70 includes a valve control unit 71, a determination unit 72, and a timing control unit 73. When the heat source unit A is switched from heating operation to the defrosting operation, the valve control unit 71 switches the channel switching valve 2, closes the heating solenoid valves 30, and opens the second flow rate control apparatus 13 and the third flow rate control apparatus 15. Also, when the indoor units B, C, and D are switched from heating operation to cooling operation, the valve control unit 71 includes a function of keeping fixed the opening degree of the first flow rate control apparatus 9. For example, the valve control unit 71 opens one of the first cooling solenoid valves 31a and the second cooling solenoid valves 31b.
[0042]
When refrigerant is circulated through the second flow rate control apparatus 13, the determination unit 72 determines whether or not the refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is generating flow noise, on the basis of the state of the refrigerant detected by the liquid state detector 81. Specifically, the determination unit 72 uses the pressures of the refrigerant detected by the liquid outflow pressure detection sensor 25 and the downstream liquid outflow pressure detection sensor 26 to determine that refrigerant is generating flow noise in the case where a pressure difference across the second flow rate control apparatus 13 is a threshold value or greater. Note that the determination unit 72 may also determine whether or not the refrigerant flowing through one of the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is generating flow noise.
[0043]
Also, when refrigerant is circulated through the cooling solenoid valves 31, the determination unit 72 determines whether or not the refrigerant flowing through the heating solenoid valves 30 is generating flow noise on the basis of the state of refrigerant detected by the gas state detector 80. Also, when refrigerant is circulated through the cooling solenoid valves 31, the determination unit 72 determines whether or not the refrigerant flowing through the cooling solenoid valves 31 is generating flow noise on the basis of the state of refrigerant detected by the gas state detector 80. Specifically, the determination unit 72 uses the pressures of the refrigerant detected by the liquid outflow pressure detection sensor 25 and the confluent pressure detection sensor 56 to determine that refrigerant is generating flow noise in the case where a pressure difference across the heating solenoid valves 30 or the cooling solenoid valves 31 is a threshold value or greater. Note that although a case of determining the state of refrigerant flowing into the heating solenoid valves 30 or the cooling solenoid valves 31 according to information detected by the confluent pressure detection sensor 56 is illustrated as an example, the configuration is not limited thereto, and information from another detection sensor may also be used as described below.
[0044]
For example, the state of refrigerant flowing into the heating solenoid valves 30 or the cooling solenoid valves 31 may also be determined by predicting a differential pressure value between the inlets and outlets of the heating solenoid valves 30 or the cooling solenoid valves 31 on the basis of information from the confluent pressure detection sensor 56 and the gas pipe temperature detection sensors 53. In addition, the state of refrigerant flowing into the heating solenoid valves 30 or the cooling solenoid valves 31 may also be determined from an outlet sub-cooling value of the indoor side heat exchangers 5 performing heating operation before being switched to cooling operation. Furthermore, the state of refrigerant flowing into the heating solenoid valves 30 or the cooling solenoid valves 31 may also be determined by predicting the refrigerant state of an indoor unit that has been stopped for an elapsed time since heating was stopped. Moreover, by combining the above, the state of refrigerant flowing into a fourth flow rate control apparatus 55 may be determined. Note that in the determination of the refrigerant state, a thermistor that detects temperature may be used as a substitute, without using the confluent pressure detection sensor 56.
[0045]
In the case where the determination unit 72 determines that the refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is generating flow noise, the timing control unit 73 controls the valve control unit 71 to successively open the heating solenoid valves 30 and the cooling solenoid valves 31. At this point, in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is not generating flow noise, the timing control unit 73 controls the valve control unit 71 to open the heating solenoid valves 30, and when a time threshold is passed, open the cooling solenoid valves 31. Note that in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is not generating flow noise, the timing control unit 73 may also control the valve control unit 71 to open the heating solenoid valves 30, and when a time threshold is passed, open any of the first cooling solenoid valves 31a and the second cooling solenoid valves 31 b. Note that in the case where it is determined that the refrigerant flowing through one of the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is generating flow noise, the timing control unit 73 may also control the valve control unit 71 to successively open the heating solenoid valves 30 and the cooling solenoid valves 31.
[0046]
On the other hand, in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is generating flow noise, the timing control unit 73 controls the valve control unit 71 to close the heating solenoid valves 30 and also open the cooling solenoid valves 31, and when a time threshold is passed, open the heating solenoid valves 30. At this time, the pressure of the refrigerant flowing through each of the cooling solenoid valves 31 is equalized by opening any of the cooling solenoid valves 31 connected to each of the liquid branch pipes 7b, 7c, and 7d, for example. Also, the timing control unit 73 successively opens the heating solenoid valves 30 connected to each of the gas branch pipes 6b, 6c, and 6d, for example. In this case, the timing control unit 73 may open one of the closed heating solenoid valves 30, and after that, open two of the closed heating solenoid valves 30, or open two of the heating solenoid valves 30, and after that, open one of the closed heating solenoid valves 30, or open one of the closed heating solenoid valves 30, and after that, open one of the heating solenoid valves 30, and after that, open one of the closed heating solenoid valves 30.
[0047]
Also, in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is generating flow noise, the timing control unit 73 controls the valve control unit 71 to open the heating solenoid valves 30 and also close the cooling solenoid valves 31, and when a time threshold is passed, open the cooling solenoid valves 31. At this time, the pressure of the refrigerant flowing through each of the heating solenoid valves 30 is equalized by opening any of the heating solenoid valves 30 connected to each of the liquid branch pipes 7b, 7c, and 7d, for example. Also, the timing control unit 73 successively opens the cooling solenoid valves 31 connected to each of the gas branch pipes 6b, 6c, and 6d, for example. In this case, the timing control unit 73 may open one of the closed cooling solenoid valves 31, and after that, open all of the remaining closed cooling solenoid valves 31, or open one of the closed cooling solenoid valves 31, and after that, open one of the closed cooling solenoid valves 31, and after that, open all of the remaining closed cooling solenoid valves 31, or open two of the closed cooling solenoid valves 31, and after that, open all of the remaining closed cooling solenoid valves 31.
[0048]
Also, in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is generating flow noise, the timing control unit 73 controls the valve control unit 71 to open the heating solenoid valves 30 and also open the cooling solenoid valves 31, and when a time threshold is passed, open the cooling solenoid valves 31. At this time, the pressure of the refrigerant flowing through each of the heating solenoid valves 30 is equalized by opening any of the heating solenoid valves 30 connected to each of the liquid branch pipes 7b, 7c, and 7d, for example. Note that in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is generating flow noise, the timing control unit 73 may also control the valve control unit 71 to open the heating solenoid valves 30 and also close the cooling solenoid valves 31, and when a time threshold is passed, open the cooling solenoid valves 31. Also, the timing control unit 73 successively opens the cooling solenoid valves 31 connected to each of the gas branch pipes 6b, 6c, and 6d, for example. In this case, the timing control unit 73 may open one of the closed cooling solenoid valves 31, and after that, open all of the remaining closed cooling solenoid valves 31, or open one of the closed cooling solenoid valves 31, and after that, open one of the closed cooling solenoid valves 31, and after that, open all of the remaining closed cooling solenoid valves 31, or open two of the closed cooling solenoid valves 31, and after that, open all of the remaining closed cooling solenoid valves 31.
[0049]
Also, when the indoor units B, C, and D are switched from heating operation to cooling operation, the timing control unit 73 controls the valve control unit 71 to open one of the multiple cooling solenoid valves 31, and in addition, in the case where the determination unit 72 has determined that the refrigerant is generating flow noise, the timing control unit 73 controls the valve control unit 71 to open one of the closed cooling solenoid valves 31. Furthermore, when an open time threshold has passed since one of the closed cooling solenoid valves 31 was opened, the timing control unit 73 may control the valve control unit 71 to open one of the closed cooling solenoid valves 31. For example, when the open time threshold has passed since the first cooling solenoid valves 31a were opened by the valve control unit 71, the timing control unit 73 controls the valve control unit 71 to open the second cooling solenoid valves 31b.
[0050]
Note that in the case where the indoor unit B and the indoor unit C are switched from heating operation to cooling operation, the valve control unit 71 may open any of the cooling solenoid valves 31 from among the first cooling solenoid valve 31a and the second cooling solenoid valve 31b connected to the indoor unit B and the first cooling solenoid valve 31a and the second cooling solenoid valve 31b connected to the indoor unit C. For example, the timing control unit 73 may control the valve control unit 71 to open from the cooling solenoid valves 31 connected to the indoor unit B of low address, for example, but the sequence of opened cooling solenoid valves 31 is not limited.
[0051]
Also, in the case where the first cooling solenoid valve 31a connected to the indoor unit B has been opened by the valve control unit 71, the timing control unit 73 may control the valve control unit 71 to open the second cooling solenoid valve 31b connected to the indoor unit B, control the valve control unit 71 to open the first cooling solenoid valve 31a connected to the indoor unit C, or control the valve control unit 71 to open the second cooling solenoid valve 31b connected to the indoor unit C. In other words, the timing control unit 73 may, not only control the valve control unit 71 to open a cooling solenoid valve 31 connected to the indoor unit B to which a cooling solenoid valve 31 opened by the valve control unit 71 is connected, but also control the valve control unit 71 to open a cooling solenoid valve 31 connected to the other indoor unit C.
[0052]
Note that in Embodiment 1, from among the indoor units B, C, and D switched from heating operation to cooling operation, the first cooling solenoid valve 31a connected to the indoor unit B of low address is opened, and after that, the second cooling solenoid valve 31 b connected to the indoor unit B is opened. Note that in the case where the Cv value of the first cooling solenoid valves 31a is greater than the Cv value of the second cooling solenoid valves 31b, the second cooling solenoid valves 31 b are opened first. Also, in the case where the second cooling solenoid valves 31b connected to each of the indoor units B, C, and D have different Cv values, the second cooling solenoid valve 31 b with the smallest Cv value is opened. In Embodiment 1, the case where the second cooling solenoid valve 31b connected to the indoor unit B is opened first by the valve control unit 71 is illustrated as an example.
[0053]
Note that during defrosting operation, in the case where the refrigerant flowing through the heating solenoid valves 30 or the cooling solenoid valves 31 is at risk of generating flow noise, the controller 70 may also control the first flow rate control apparatus 9 to pass refrigerant to the indoor units B, C, and D. With this arrangement, since the quantity of refrigerant flowing through the heating solenoid valves 30 and the cooling solenoid valves 31 decreases, the occurrence of flow noise may be reduced. In addition, the pipes connected to the second flow rate control apparatus 13 and the third flow rate control apparatus 15 may be increased in diameter. With this configuration, since the pressure loss of refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 decreases, the occurrence of refrigerant flow noise may be reduced. [0054]
Next, operations of the air conditioning apparatus 100 will be described. As operating modes, the air conditioning apparatus 100 includes cooling only operation, heating only operation, cooling main operation, heating main operation, and defrosting operation. Cooling only operation is a mode where all of the indoor units B, C, and D execute cooling operation. Heating only operation is a mode in which all of the indoor units B, C, and D execute heating operation. Cooling main operation is a mode in which, during simultaneous cooling and heating operation, the capacity of the cooling operation is greater than the capacity of the heating operation. Heating main operation is a mode in which, during simultaneous cooling and heating operation, the capacity of the heating operation is greater than the capacity of the cooling operation. Defrosting operation is a mode that removes frost adhering to the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42 in the case where the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42 has become frosted while heating only operation or heating main operation is being executed.
[0055] (Cooling only operation)
Fig. 3 is a circuit diagram illustrating a state during cooling only operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. First, cooling only operation will be described. In the air conditioning apparatus 100, all of the indoor units B, C, and D are executing cooling operation. As illustrated in Fig. 3, high-temperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the channel switching valve 2, and exchanges heat with air sent by the heat source side fan 20 of variable airflow volume in the heat source side heat exchange unit 3 to condense and liquefy. After that, this refrigerant circulates through the third check valve 32, the second connecting pipe 7, the gasliquid separation apparatus 12, and the second flow rate control apparatus 13 in this order, additionally passes through the second branching unit 11 and the liquid branch pipes 7b, 7c, and 7d, and flows into the indoor units B, C, and D.
[0056]
Subsequently, the refrigerant flowing into the indoor units B, C, and D is depressurized to a low pressure by the first flow rate control apparatus 9 controlled according to the amount of superheating on the outlet side of the indoor side heat exchangers 5. The depressurized refrigerant flows into the indoor side heat exchangers 5, and exchanges heat with indoor air in the indoor side heat exchangers 5 to evaporate and gasify. At this time, the indoor space is cooled. Subsequently, this refrigerant that has become a gas state passes through the gas branch pipes 6b, 6c, and 6d, the first cooling solenoid valves 31a and the second cooling solenoid valves 31 b of the first branching unit 10, the first connecting pipe 6, the fourth check valve 33, the channel switching valve 2 of the heat source unit A, and the accumulator 4, and is suctioned into the compressor 1.
[0057]
Note that in cooling only operation, all of the heating solenoid valves 30 are closed. Also, all of the first cooling solenoid valves 31a and the second cooling solenoid valves 31 b are opened. Additionally, since the first connecting pipe 6 is at low pressure and the second connecting pipe 7 is at high pressure, the refrigerant circulates through the third check valve 32 and the fourth check valve 33. [0058]
Also, in this circulation cycle, a portion of the refrigerant passing through the second flow rate control apparatus 13 enters the first bypass pipe 14. Subsequently, in the second heat exchange unit 16, the refrigerant that has been depressurized to a low pressure by the third flow rate control apparatus 15 exchanges heat with the refrigerant that has passed through the second flow rate control apparatus 13, or in other words, the refrigerant about to be branched to the first bypass pipe 14, and thereby evaporates. Furthermore, in the first heat exchange unit 19, the refrigerant exchanges heat with the refrigerant that is about to flow into the second flow rate control apparatus 13, and evaporates. The evaporated refrigerant flows into the first connecting pipe 6 and the fourth check valve 33, passes through the channel switching valve 2 and the accumulator 4 of the heat source unit A, and is suctioned into the compressor 1.
[0059]
On the other hand, in the first heat exchange unit 19 and the second heat exchange unit 16, the refrigerant exchanges heat with the refrigerant that has flowed into the first bypass pipe 14 and has been depressurized to a low pressure by the third flow rate control apparatus 15, and is thereby cooled, and the refrigerant sufficiently imparted with sub-cooling passes through the first check valves 50b, 50c, and 50d of the second branching unit 11 and flows into the indoor units B, C, and D that are demanded provide cooling. Here, the controller 70 adjusts the capacity of the variable-capacity compressor 1 and the airflow volume of the heat source side fan such that the evaporating temperature of the indoor units B, C, and D and the condensing temperature of the heat source side heat exchange unit 3 reach predetermined target temperatures. For this reason, the targeted cooling capacity may be obtained in each of the indoor units B, C, and D. Note that the condensing temperature of the heat source side heat exchange unit 3 is computed as the saturation temperature for the pressure detected by the discharge pressure detection sensor 18.
[0060] (Heating only operating mode)
Fig. 4 is a circuit diagram illustrating a state during heating only operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. Next, heating only operation will be described. In the air conditioning apparatus 100, all of the indoor units B, C, and D are executing heating operation. As illustrated in Fig. 4, high-temperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the channel switching valve 2, passes through the fifth check valve 34, the second connecting pipe 7, the gas-liquid separation apparatus 12, the heating solenoid valves 30 of the first branching unit 10, and the gas branch pipes 6b, 6c, and 6d in order, and flows into the indoor units B, C, and D. The refrigerant flowing into the indoor units B, C, and D exchanges heat with indoor air to condense and liquefy. At this time, the indoor space is heated. Subsequently, the refrigerant in this state passes through the first flow rate control apparatus 9 controlled by the amount of sub-cooling on the outlet side of each of the indoor side heat exchangers 5.
[0061]
The refrigerant passing through the first flow rate control apparatus 9 flows into the channel switching valve 2 from the liquid branch pipes 7b, 7c, and 7d, and converges after passing through the second check valves 52b, 52c, and 52d. The refrigerant converging in the second branching unit 11 is additionally guided between the second flow rate control apparatus 13 and the second heat exchange unit 16 of the second connecting pipe 7, and passes through the third flow rate control apparatus 15. Also, the refrigerant is depressurized to a low-pressure two-phase gas-liquid by the first flow rate control apparatus 9 and the third flow rate control apparatus 15.
[0062]
Subsequently, the refrigerant depressurized to a low pressure passes through the first connecting pipe 6 and the sixth check valve 35 of the heat source unit A, flows into the heat source side heat exchange unit 3, and exchanges heat with air sent by the heat source side fan 20 of variable airflow volume to evaporate. The refrigerant that has evaporated to a gas state passes through the channel switching valve 2 and the accumulator 4, and is suctioned into the compressor 1. [0063]
Note that in heating only operation, all of the heating solenoid valves 30 are opened. Also, all of the first cooling solenoid valves 31 a and the second cooling solenoid valves 31b are closed.
[0064]
Additionally, in this circulation cycle, since the first connecting pipe 6 is at low pressure and the second connecting pipe 7 is at high pressure, the refrigerant circulates through the fifth check valve 34 and the sixth check valve 35. Also, since the liquid branch pipes 7b, 7c, and 7d are at higher pressure than the second connecting pipe 7, refrigerant does not pass through the first check valves 50b, 50c, and 50d. Here, the controller 70 adjusts the capacity of the variable-capacity compressor 1 and the airflow volume of the heat source side fan 20 such that the condensing temperature of the indoor units B, C, and D and the evaporating temperature of the heat source side heat exchange unit 3 reach predetermined target temperatures. For this reason, the targeted heating capacity may be obtained in each of the indoor units B, C, and D.
[0065] (Cooling main operation)
Fig. 5 is a circuit diagram illustrating a state during cooling main operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. Next, cooling main operation will be described. In the air conditioning apparatus 100, there is a cooling demand issued from the indoor units B and C, and a heating demand issued from the indoor unit D. As illustrated in Fig. 5, hightemperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the channel switching valve 2, flows into the heat source side heat exchange unit 3, and exchanges heat with air sent by the heat source side fan 20 of variable airflow volume to enter a two-phase high-temperature and high-pressure state.
[0066]
Here, the controller 70 adjusts the capacity of the variable-capacity compressor 1 and the airflow volume of the heat source side fan 20 such that the evaporating temperature and the condensing temperature of the indoor units B, C, and D reach predetermined target temperatures. Also, the controller 70 opens and closes the first solenoid opening and closing valve 44, the second solenoid opening and closing valve 45, the third solenoid opening and closing valve 46, and the fourth solenoid opening and closing valve 47 on both sides of the first heat source side heat exchanger 41 and the second heat source side heat exchanger 42 to adjust the heat transfer area. In addition, the controller 70 opens and closes the fifth solenoid opening and closing valve 48 of the heat source side bypass channel 43 to adjust the flow rate of refrigerant circulating through the first heat source side heat exchanger 41 and the second heat source side heat exchanger 42. With this arrangement, a desired amount of heat exchange may be obtained in the heat source side heat exchange unit 3, while in addition, the targeted heating capacity or cooling capacity may be obtained in each of the indoor units B, C, and D.
[0067]
The refrigerant in the two-phase high-temperature and high-pressure state passes through the third check valve 32 and the second connecting pipe 7, is sent to the gas-liquid separation apparatus 12 of the relay unit E, and is separated into gas refrigerant and liquid refrigerant. Additionally, the gas refrigerant separated by the gas-liquid separation apparatus 12 passes through the heating solenoid valves 30 of the first branching unit 10 and the gas branch pipe 6d, flows into the indoor unit D that is demanded to provide heating, and exchanges heat with indoor air in the indoor side heat exchanger 5 to condense and liquefy. At this time, the indoor space is heated by the indoor unit D. Additionally, the refrigerant flowing out from the indoor side heat exchanger 5 passes through the first flow rate control apparatus 9 controlled by the amount of sub-cooling on the outlet side of the indoor side heat exchanger 5 of the indoor unit D, is depressurized slightly, and flows into the second branching unit 11. The refrigerant passes through the second bypass pipe 51 that includes the second check valve 52d, and flows into the downstream side of the second flow rate control apparatus 13 of the second connecting pipe 7.
[0068]
On the other hand, the liquid refrigerant separated by the gas-liquid separation apparatus 12 passes through the second flow rate control apparatus 13 controlled by the pressure detected by the liquid outflow pressure detection sensor 25 and the pressure detected by the downstream liquid outflow pressure detection sensor 26, and converges with the refrigerant passing through the indoor unit D that is demanded to provide heating. After that, the refrigerant flows into the second heat exchange unit 16, and is cooled by the second heat exchange unit 16.
[0069]
Additionally, a portion of the refrigerant cooled by the second heat exchange unit 16 passes through the first check valves 50b and 50c, passes through the liquid branch pipes 7b and 7c, and enters the indoor units B and C that are demanded to provide cooling. The refrigerant flowing into the indoor units B and C enters the first flow rate control apparatus 9 controlled by the amount of superheat on the outlet side of each indoor side heat exchanger 5 of the indoor units B and C, and after being depressurized, enters the indoor side heat exchangers 5 and exchanges heat to evaporate and gasify. At this time, each indoor space is cooled by the indoor units B and C. After that, the refrigerant flows into the first connecting pipe 6 via the first cooling solenoid valves 31a and the second cooling solenoid valves 31b.
[0070]
On the other hand, the remaining portion of the refrigerant cooled by the second heat exchange unit 16 passes through the third flow rate control apparatus 15 controlled such that the pressure difference between the pressure detected by the liquid outflow pressure detection sensor 25 and the pressure detected by the downstream liquid outflow pressure detection sensor 26 stays within a predetermined range. After that, after the refrigerant exchanges heat in the second heat exchange unit 16 and the first heat exchange unit 19 to evaporate, the refrigerant flows into the first connecting pipe 6 and converges with the refrigerant flowing through the indoor units B and C. The refrigerant converging in the first connecting pipe 6 passes through the fourth check valve 33, the channel switching valve 2, and the accumulator 4 of the heat source unit A, and is suctioned into the compressor 1.
[0071]
Note that in cooling main operation, the heating solenoid valves 30 connected to the indoor units B and C are closed. Also, the heating solenoid valve 30 connected to the indoor unit D is opened. Furthermore, the first cooling solenoid valves 31a and the second cooling solenoid valves 31b connected to the indoor units B and C are opened. Furthermore, the first cooling solenoid valve 31a and the second cooling solenoid valve 31b connected to the indoor unit D are closed. [0072]
Additionally, since the first connecting pipe 6 is at low pressure and the second connecting pipe 7 is at high pressure, the refrigerant circulates through the third check valve 32 and the fourth check valve 33. Furthermore, since the liquid branch pipes 7b and 7c are at a pressure lower than that of the second connecting pipe 7, refrigerant does not pass through the second check valves 52b and 52c. Furthermore, since the liquid branch pipe 7d is at a pressure higher than the second connecting pipe 7, refrigerant does not pass through the first check valve 50d. The first check valves 50 and the second check valves 52 prevent the refrigerant passing through the indoor unit D with the heating demand issued from flowing into the indoor units B and C with the cooling demand without passing through the second heat exchange unit 16 and without being sufficiently imparted with sub-cooling.
[0073] (Heating main operation)
Fig. 6 is a circuit diagram illustrating a state during heating main operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. Next, heating main operation will be described. In the air conditioning apparatus 100, a demand for heating is issued from the indoor units B and C, and a demand for cooling is issued from the indoor unit D. As illustrated in Fig. 6, hightemperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the channel switching valve 2, the fifth check valve 34, and the second connecting pipe 7, is sent to the relay unit E, and passes through the gasliquid separation apparatus 12. The refrigerant passing through the gas-liquid separation apparatus 12 passes through the heating solenoid valves 30 of the first branching unit 10 and the gas branch pipes 6b and 6c in this order, flows into the indoor units B and C that are demanded to provide heating, and exchanges heat with indoor air in the indoor side heat exchangers 5 to condense and liquefy. At this time, each indoor space is heated by the indoor units B and C. The condensed and liquefied refrigerant passes through the first flow rate control apparatus 9 controlled by the amount of sub-cooling on the outlet side of each indoor side heat exchanger 5 of the indoor units C and D, is depressurized slightly, and flows into the second branching unit 11.
[0074]
The refrigerant flowing into the second branching unit 11 passes through the second bypass pipe 51 that includes the second check valves 52b and 52c, converges in the second connecting pipe 7, and is cooled by the second heat exchange unit 16. A portion of the refrigerant cooled by the second heat exchange unit 16 passes through the first check valve 50d and the liquid branch pipe 7d, and enters the indoor unit D that is demanded to provide cooling. Subsequently, the refrigerant entering the indoor unit D enters the first flow rate control apparatus 9 controlled by the amount of superheating on the outlet side of the indoor side heat exchanger 5, and after being depressurized, enters the indoor side heat exchanger 5 and exchanges heat to evaporate and gasify. At this time, the indoor space is cooled by the indoor unit D. After that, the refrigerant flows into the first connecting pipe 6 via the first cooling solenoid valves 31a and the second cooling solenoid valves 31b.
[0075]
On the other hand, the remaining portion of the refrigerant cooled by the second heat exchange unit 16 passes through the third flow rate control apparatus 15 controlled such that the pressure difference between the pressure detected by the liquid outflow pressure detection sensor 25 and the pressure detected by the downstream liquid outflow pressure detection sensor 26 stays within a predetermined range. The refrigerant passing through the third flow rate control apparatus 15 exchanges heat with the refrigerant flowing out of the indoor units B and C in the second heat exchange unit 16 to evaporate. After that, the refrigerant converges with the refrigerant passing through the indoor unit D that is demanded to provide cooling, passes through the first connecting pipe 6, and flows into the sixth check valve 35 and the heat source side heat exchange unit 3 of the heat source unit A. The refrigerant flowing into the heat source side heat exchange unit 3 exchanges heat with air sent by the heat source side fan 20 of variable airflow volume to evaporate and gasify.
[0076]
Here, the controller 70 adjusts the capacity of the variable-capacity compressor 1 and the airflow volume of the heat source side fan 20 such that the evaporating temperature of the indoor unit D with the cooling demand and the condensing temperature of the indoor units B and C with the heating demand reach predetermined target temperatures. Also, the controller 70 opens and closes the first solenoid opening and closing valve 44, the second solenoid opening and closing valve 45, the third solenoid opening and closing valve 46, and the fourth solenoid opening and closing valve 47 on both sides of the first heat source side heat exchanger 41 and the second heat source side heat exchanger 42 to adjust the heat transfer area. In addition, the controller 70 opens and closes the fifth solenoid opening and closing valve 48 of the heat source side bypass channel 43 to adjust the flow rate of refrigerant circulating through the first heat source side heat exchanger 41 and the second heat source side heat exchanger 42. With this arrangement, a desired amount of heat exchange may be obtained in the heat source side heat exchange unit 3, while in addition, the targeted heating capacity or cooling capacity may be obtained in each of the indoor units B, C, and D. Subsequently, the refrigerant passes through the channel switching valve 2 and the accumulator 4 of the heat source unit A, and is suctioned into the compressor 1.
[0077]
Note that in heating main operation, the heating solenoid valves 30 connected to the indoor units B and C are opened. Also, the heating solenoid valve 30 connected to the indoor unit D is closed. Furthermore, the first cooling solenoid valves 31a and the second cooling solenoid valves 31b connected to the indoor units B and C are closed. Furthermore, the first cooling solenoid valve 31a and the second cooling solenoid valve 31b connected to the indoor unit D is closed. [0078]
Additionally, since the first connecting pipe 6 is at low pressure and the second connecting pipe 7 is at high pressure, the refrigerant circulates through the fifth check valve 34 and the sixth check valve 35. Note that the second flow rate control apparatus 13 is closed. Furthermore, since the liquid branch pipes 7b and 7c are at higher pressure than the second connecting pipe 7, refrigerant does not pass through the first check valves 50b and 50c. Also, since the liquid branch pipe 7d is at lower pressure than the second connecting pipe 7, refrigerant does not pass through the second check valve 52d. The first check valves 50 and the second check valves 52 prevent the refrigerant passing through the indoor units B and C with the heating demand from flowing into the indoor unit D with the cooling demand without passing through the second heat exchange unit 16 and without being sufficiently imparted with sub-cooling.
[0079] (Defrosting operation)
Next, defrosting operation will be described. In the air conditioning apparatus 100, when heating only operation or heating main operation is executed, the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42 may become frosted in some cases. To remove the frost adhering to the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42, defrosting operation is executed.
[0080] (First state)
Fig. 7 is a circuit diagram illustrating a first state during defrosting operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. Next, the first state of defrosting operation will be described. When defrosting operation is executed, refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 may generate flow noise in some cases. The first state is the state of the case where the refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is not generating flow noise. As illustrated in Fig. 7, hightemperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the channel switching valve 2, flows into the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42 in the heat source side heat exchange unit 3, and melts frost adhering to the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42. Additionally, in the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42, the refrigerant exchanges heat with air to condense and liquefy. After that, the refrigerant flows through the third check valve 32, the second connecting pipe 7, and the gas-liquid separation apparatus 12 in this order.
[0081]
At this point, the heating solenoid valves 30 are closed. For this reason, all of the refrigerant flows out from the liquid outflow side of the gas-liquid separation apparatus 12, passes through the first heat exchange unit 19, and flows into the second flow rate control apparatus 13. After being depressurized to a low pressure by the second flow rate control apparatus 13, the refrigerant flows to the second heat exchange unit 16, enters the first bypass pipe 14, and flows into the third flow rate control apparatus 15. In the second heat exchange unit 16, the refrigerant that has been depressurized to a low pressure by the third flow rate control apparatus 15 exchanges heat with the refrigerant that has passed through the second flow rate control apparatus 13, or in other words, the refrigerant about to be branched to the first bypass pipe 14, and thereby evaporates. Furthermore, in the first heat exchange unit 19, the refrigerant exchanges heat with the refrigerant that is about to flow into the second flow rate control apparatus 13, and then evaporates. The evaporated refrigerant flows into the first connecting pipe 6 and the fourth check valve 33, passes through the channel switching valve 2 and the accumulator 4 of the heat source unit A, and is suctioned into the compressor 1.
[0082] (Second state)
Fig. 8 is a circuit diagram illustrating a second state during defrosting operation of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. Next, the second state of defrosting operation will be described. When defrosting operation is executed, refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 may produce flow noise in some cases. The second state is the state of the case where the refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is generating flow noise. As illustrated in Fig. 8, hightemperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the channel switching valve 2, flows into the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42 in the heat source side heat exchange unit 3, and melts frost adhering to the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42. Additionally, in the first heat source side heat exchanger 41 or the second heat source side heat exchanger 42, the refrigerant exchanges heat with air to condense and liquefy. After that, the refrigerant flows through the third check valve 32, the second connecting pipe 7, and the gas-liquid separation apparatus 12 in order.
[0083]
At this point, the heating solenoid valves 30 and the cooling solenoid valves 31 are opened. A portion of the refrigerant flows out from the liquid outflow side of the gas-liquid separation apparatus 12, passes through the first heat exchange unit 19, and flows into the second flow rate control apparatus 13. After being depressurized to a low pressure by the second flow rate control apparatus 13, the refrigerant flows to the second heat exchange unit 16, enters the first bypass pipe 14, and flows into the third flow rate control apparatus 15. In the second heat exchange unit 16, the refrigerant that has been depressurized to a low pressure by the third flow rate control apparatus 15 exchanges heat with the refrigerant that has passed through the second flow rate control apparatus 13, or in other words, the refrigerant about to be branched to the first bypass pipe 14, and thereby evaporates. Furthermore, in the first heat exchange unit 19, the refrigerant exchanges heat with the refrigerant that is about to flow into the second flow rate control apparatus 13, and then evaporates. The evaporated refrigerant reaches the first connecting pipe 6.
[0084]
On the other hand, a portion of the refrigerant flows out from the gas outflow side of the gas-liquid separation apparatus 12, passes through the heating solenoid valves 30, through the cooling solenoid valves 31, and reaches the first connecting pipe 6. In the first connecting pipe 6, the refrigerant flowing out from the liquid outflow side of the gas-liquid separation apparatus 12 and the refrigerant flowing out from the gas outflow side of the gas-liquid separation apparatus 12 converge. The converging refrigerant flows into the fourth check valve 33, passes through the channel switching valve 2 and the accumulator 4 of the heat source unit A, and is suctioned into the compressor 1.
[0085]
Fig. 9 is a flowchart illustrating operations of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. Next, the operations of the controller 70 will be described. When defrosting operation is executed, refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 may produce flow noise in some cases. In Embodiment 1, the production of flow noise by refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is reduced by the controller 70. Furthermore, in Embodiment 1, the production of flow noise by refrigerant flowing through the heating solenoid valves 30 is reduced by the controller 70. [0086]
When switching from heating only operation or heating main operation to defrosting operation, as illustrated in Fig. 9, the valve control unit 71 switches the channel switching valve 2, closes the heating solenoid valves 30, and opens the second flow rate control apparatus 13 and the third flow rate control apparatus 15 (step ST100). With this arrangement, refrigerant flows as illustrated in Fig. 7 as the first state of defrosting operation. Next, the determination unit 72 determines whether or not the refrigerant flowing through the second flow rate control apparatus 13 and the third flow rate control apparatus 15 is generating flow noise (step ST200). In the case of determining that flow noise is not being produced (step ST200, No), the control returns to step ST200. On the other hand, in the case of determining that flow noise is being produced (step ST200, Yes), the control proceeds to the second state of defrosting operation, and the amount of refrigerant flowing through the second flow rate control apparatus 13 is decreased. Examples of flow noise being produced by refrigerant flowing through the second flow rate control apparatus 13 include when a large amount of refrigerant is flowing, when the horsepower of the heat source unit A increases, when the outdoor temperature falls, or when recovering from a pressure loss. The heating solenoid valves 30 are opened by the valve control unit 71 (step ST300).
[0087]
After that, the cooling solenoid valves 31 are opened, thereby connecting the second connecting pipe 7 through which high-pressure refrigerant flows with the first connecting pipe 6 through which low-pressure refrigerant flows. In this way, in the case where there is a large differential pressure across the heating solenoid valves 30 and the cooling solenoid valves 31, there is a risk of noise and shock occurring in the heating solenoid valves 30 and the cooling solenoid valves 31. Accordingly, the determination unit 72 determines whether or not the refrigerant flowing through the heating solenoid valves 30 is generating flow noise (step ST400). In the case of determining that flow noise is not being produced (step ST400, No), the control returns to step ST200. On the other hand, in the case of determining that flow noise is being produced (step ST400, Yes), the valve control unit 71 closes the heating solenoid valves 30 and the opens the cooling solenoid valves 31 (step ST500). At this time, the closed cooling solenoid valves 31 may be opened one at a time, or all at once. With this configuration, the pressure of the refrigerant flowing through each of the cooling solenoid valves 31 is equalized.
[0088]
After that, it is determined whether or not a time threshold has passed (step ST600). In the case where the time threshold has not passed (step ST600, No), the control returns to step ST600. On the other hand, in the case where the time threshold has passed (step ST600, Yes), it is determined that the equalization is sufficiently conducted, and the valve control unit 71 opens the heating solenoid valves 30 (step ST700). With this configuration, refrigerant flows as illustrated in Fig. 8 as the second state of defrosting operation. At this time, the closed heating solenoid valves 30 may be opened one at a time, or all at once. In the case of opening the closed heating solenoid valves 30 one at a time, the pressure of the refrigerant flowing through the heating solenoid valves 30 is equalized. Subsequently, control is continued.
[0089]
Fig. 10 is a flowchart illustrating operations of the air conditioning apparatus 100 according to Embodiment 1 of the present invention. Next, operations of the controller 70 when switching the indoor units B, C, and D from heating operation to cooling operation will be described. When switching the indoor units B, C, and D from heating operation to cooling operation, the high-temperature and high-pressure gas refrigerant and the high-temperature and high-pressure liquid refrigerant that had been flowing during heating passes through the first cooling solenoid valves 31a and the second cooling solenoid valves 31b, and flows into the first connecting pipe 6 in a state of low pressure during cooling. For this reason, a large pressure difference occurs across the cooling solenoid valves 31, and there is a risk of flow noise being produced by the refrigerant near the cooling solenoid valves 31. In Embodiment 1, the controller 70 minimizes the refrigerant flow noise produced from the relay unit E which includes the cooling solenoid valves 31. Note that in Embodiment 1, it is assumed that the indoor units B, C, and D have ascending addresses in that order. [0090]
As illustrated in Fig. 10, when the indoor units B and C are switched from heating operation to cooling operation, for example, the timing control unit 73 controls the valve control unit 71 to keep fixed the opening degree of the first flow rate control apparatus 9 (step ST 1). With this arrangement, the pressure of the first connecting pipe 6 escapes to the second connecting pipe 7. Consequently, the pressure on the first connecting pipe 6 side in the first cooling solenoid valves 31a and the second cooling solenoid valves 31 b falls, and the pressure of the first connecting pipe 6 and the pressure of the second connecting pipe 7 being to equalize. Also, the timing control unit 73 controls the valve control unit 71 such that the first cooling solenoid valve 31a connected to the indoor unit B is opened (step ST2).
[0091]
Fig. 11 is a flowchart illustrating operations of the air conditioning apparatus
100 according to Embodiment 1 of the present invention. Next, when refrigerant circulates through the second cooling solenoid valves 31b opened by the valve control unit 71, the determination unit 72 determines whether or not flow noise is being produced, on the basis of the state of the refrigerant detected by the gas state detector 80 (step ST3). Specifically, as illustrated in Fig. 11, the determination unit 72 determines whether or not a refrigerant pressure P detected by the confluent pressure detection sensor 56 is equal to or greater than a pressure threshold Po (step ST31). As illustrated in Fig. 10, in the case where the refrigerant pressure P is less than the pressure threshold Po (step ST3, No), since the difference between the pressure of the first connecting pipe 6 and the pressure of the second connecting pipe 7 is small, it is determined that the refrigerant is not generating flow noise, and the control returns to normal operation. On the other hand, in the case where the refrigerant pressure P is the pressure threshold Po or greater (step ST3, Yes), since the difference between the pressure of the first connecting pipe 6 and the pressure of the second connecting pipe 7 is large, it is determined that there is a risk of the refrigerant generating flow noise, and the control proceeds to step ST4. Note that the determination unit 72 may also use the pressures of the refrigerant detected by the liquid outflow pressure detection sensor 25 and the confluent pressure detection sensor 56 to determine that refrigerant is generating flow noise in the case where a pressure difference across the cooling solenoid valves 31 is a threshold value or greater.
[0092]
In step ST4, the timing control unit 73 checks if an open time threshold has passed since the opening of the second cooling solenoid valves 31 b. In the case where the open time threshold has not passed (step ST4, No), step ST4 is repeated. In the case where the open time threshold has passed (step ST4, Yes), the timing control unit 73 selects the second cooling solenoid valve 31b connected to the indoor unit B of low address (step ST5). After that, the selected second cooling solenoid valve 31b is opened (step ST6). With this arrangement, multiple cooling solenoid valves 31 are not opened at the same time. Consequently, refrigerant may be prevented from flowing forcefully through the first connecting pipe 6. After that, in the indoor units with a cooling demand, it is determined whether or not a closed cooling solenoid valve 31 exists (step ST7). In the case where a closed cooling solenoid valve 31 exists (step ST7, Yes), the control returns to step ST3. On the other hand, in the case where a closed cooling solenoid valve 31 does not exist (step ST7, No), the control ends.
[0093]
At this point, in Embodiment 1, not only the indoor unit B but also the indoor unit C has a cooling demand. For this reason, in step ST7, a closed cooling solenoid valve 31 exists, and the control returns to step ST3. Additionally, in the case where the refrigerant pressure P is still equal to or greater than the pressure threshold Po, the control proceeds to step ST4. At this point, the second cooling solenoid valve 31 b connected to the indoor unit C is selected, for example. Subsequently, it is checked whether the open time threshold has passed since the opening of the second cooling solenoid valve 31b connected to the indoor unit B in the other branch (step ST5), and in the case where the open time threshold has passed, the selected second cooling solenoid valve 31b connected to the indoor unit C is opened (step ST6).
[0094]
Note that since the second cooling solenoid valve 31b connected to the indoor unit D is closed, in step ST7, the control returns to step ST3 again. Additionally, in the case where the refrigerant pressure P is still equal to or greater than the pressure threshold Po, the control proceeds to step ST4. At this point, the second cooling solenoid valve 31 b connected to the indoor unit D is selected. Subsequently, it is checked whether the open time threshold has passed since the opening of the second cooling solenoid valve 31b connected to the indoor unit D closed previously (step ST5), and in the case where the open time threshold has passed, the selected second cooling solenoid valve 31b connected to the indoor unit D is opened (step ST6). Additionally, in step ST7, since a closed cooling solenoid valve 31 does not exist, the control ends.
[0095]
According to Embodiment 1, during defrosting operation, in a case of determining that flow noise has occurred in refrigerant flowing through the second flow rate control apparatus 13 or the third flow rate control apparatus 15, the heating solenoid valves 30 and the cooling solenoid valves 31 are opened successively. With this arrangement, since the amount of refrigerant flowing through the second flow rate control apparatus 13 or the third flow rate control apparatus 15 is decreased, the occurrence of flow noise by the refrigerant flowing through the second flow rate control apparatus 13 or the third flow rate control apparatus 15 is minimized. Consequently, quiet operation of the air conditioning apparatus 100 is realized. Also, since quiet operation is realized, freedom in installation location of the relay unit E is enhanced.
[0096]
Also, the gas state detector 80 that detects the state of refrigerant flowing through the gas branch pipes 6b, 6c, and 6d is additionally provided, and when refrigerant circulates through the heating solenoid valves 30, the determination unit 72 includes a function of determining whether or not the refrigerant flowing through the heating solenoid valves 30 is generating flow noise on the basis of the refrigerant state detected by the gas state detector 80. Subsequently, in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is not generating flow noise, the timing control unit 73 controls the valve control unit 71 to open the heating solenoid valves 30, and when a time threshold is passed, open the cooling solenoid valves 31. Also, the multiple cooling solenoid valves 31 are connected in parallel with each other, and in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is not generating flow noise, the timing control unit 73 controls the valve control unit 71 to open the heating solenoid valves 30, and when a time threshold is passed, open the multiple cooling solenoid valves 31. With this configuration, the generation of flow noise is minimized in the second flow rate control apparatus 13, the third flow rate control apparatus 15, and the heating solenoid valves 30.
[0097]
In the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is generating flow noise, the timing control unit 73 controls the valve control unit 71 to close the heating solenoid valves 30 and also open the cooling solenoid valves 31, and when a time threshold is passed, open the heating solenoid valves 30. The timing control unit 73 controls the valve control unit 71 to successively open the heating solenoid valves 30 connected to each of the gas branch pipes 6b, 6c, and 6d. With this arrangement, the pressure of the refrigerant flowing through the heating solenoid valves 30 and the cooling solenoid valves 31 is equalized. Consequently, flow noise of the refrigerant can be minimized.
[0098]
In the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is generating flow noise, the timing control unit 73 controls the valve control unit 71 to open the heating solenoid valves 30 and also close the cooling solenoid valves 31, and when a time threshold is passed, open the cooling solenoid valves 31. Also, the multiple cooling solenoid valves 31 are connected in parallel with each other, and in the case where the determination unit 72 has determined that the refrigerant flowing through the heating solenoid valves 30 is generating flow noise, the timing control unit 73 controls the valve control unit 71 to open the heating solenoid valves 30 while also opening one of the cooling solenoid valves 31, and when a time threshold is passed, open one of the closed cooling solenoid valves 31. The valve control unit 71 controls the valve control unit 71 to successively open the cooling solenoid valves 31 connected to each of the gas branch pipes 6b, 6c, and 6d. With this configuration, the pressure of the refrigerant flowing through the heating solenoid valves 30 and the cooling solenoid valves 31 is equalized. Consequently, flow noise of the refrigerant may be minimized.
[0099]
Also, when the indoor units B, C, and D are switched from heating operation to cooling operation, the timing control unit 73 controls the valve control unit 71 to open one of the multiple cooling solenoid valves 31, and in addition, in the case of determining that the refrigerant is generating flow noise, the timing control unit 73 controls the valve control unit 71 to open one of the closed cooling solenoid valves 31. In this way, since the multiple cooling solenoid valves 31 are opened successively, refrigerant flow noise may be reduced even without using an orifice.
Consequently, a shutoff function with respect to refrigerant leakage may be improved, and in addition, refrigerant flow noise may be reduced.
[0100]
Fig. 12 is a circuit diagram illustrating an air conditioning apparatus 200 of the related art. As illustrated in Fig. 12, in the air conditioning apparatus 200 of the related art, a first branching unit 110 includes a first cooling solenoid valve a, a second cooling solenoid valve c, an orifice d, and a heating solenoid valve b. When the air conditioning apparatus 200 of the related art is switched from heating operation to cooling operation, refrigerant flows gradually in the order of the orifice d, the first cooling solenoid valve a, and the second cooling solenoid valve c. This configuration is aimed at reducing the flow noise of refrigerant. However, the orifice d serves to reduce the flow noise of refrigerant by bypassing high-pressure pressure and low-pressure pressure to equalize the pressure between the high-pressure side pipe and the low-pressure side pipe. Consequently, since the refrigerant supplied to an indoor unit is bypassed during heating operation, the orifice d performs poorly as a shutoff function.
[0101]
In contrast, in Embodiment 1, the valve control unit 71 opens one of the multiple cooling solenoid valves 31, and in the case where the timing control unit 73 determines that the refrigerant is generating flow noise, the timing control unit 73 controls the valve control unit 71 to open one of the closed cooling solenoid valves 31. For this reason, refrigerant flow noise may be reduced even without using an orifice. Consequently, a shutoff function with respect to refrigerant leakage may be improved, and in addition, refrigerant flow noise may be reduced.
[0102]
Also, when switching the indoor units B, C, and D from heating operation to cooling operation, the valve control unit 71 includes a function of keeping fixed the opening degree of the first flow rate control apparatus 9. With this arrangement, pressure is equalized between the first connecting pipe 6 and the second connecting pipe 7. Consequently, a forceful flow of refrigerant is suppressed.
[0103]
Furthermore, when an open time threshold has passed since one of the closed cooling solenoid valves 31 was opened, the timing control unit 73 controls the valve control unit 71 to open one of the closed cooling solenoid valves 31. Consequently, a forceful flow of refrigerant is suppressed. For this reason, flow noise of the refrigerant may be decreased further.
[0104]
Furthermore, the gas state detector 80 includes the confluent pressure detection sensor 56 that detects the pressure of refrigerant circulating through the portion to which the liquid branch pipes 7b, 7c, and 7d and the first connecting pipe 6 are connected, and the liquid outflow pressure detection sensor 25 that detects the pressure of refrigerant on the liquid outflow side of the gas-liquid separation apparatus 12, and the determination unit 72 determines that refrigerant is generating flow noise in the case where the pressure difference of the receptacle detected by the confluent pressure detection sensor 56 and the liquid outflow pressure detection sensor 25 is a threshold value or greater. With this arrangement, the pressure of the first connecting pipe 6 may be normalized. Consequently, generation of flow noise of the refrigerant may be further decreased.
[0105] (First modification)
Fig. 13 is a flowchart illustrating operations of the air conditioning apparatus 100 according to a first modification of Embodiment 1 of the present invention. Next, the first modification of Embodiment 1 will be described. In the first modification, the operation in step ST3 of Fig. 10 is different from Embodiment 1, and the determination unit 72 determines whether or not refrigerant is generating flow noise on the basis of the difference between the pressure in one cooling solenoid valve 31 and the pressure in another cooling solenoid valve 31.
[0106]
As illustrated in Fig. 13, the determination unit 72 determines whether or not a difference APa between the pressure in one of the first cooling solenoid valves 31a and the second cooling solenoid valves 31 b and the pressure in another of the first cooling solenoid valves 31a and the second cooling solenoid valves 31b is a pressure threshold ΔΡο or greater (step ST41). Specifically, the determination unit 72 determines that refrigerant is generating flow noise in the case where the difference APa between the pressure of refrigerant detected by the confluent pressure detection sensor 56 and the pressure of refrigerant corresponding to the temperature of refrigerant detected by the gas pipe temperature detection sensors 53 is the pressure threshold ΔΡο or greater. In other words, the pressure of one of the first cooling solenoid valves 31a and the second cooling solenoid valves 31b is detected by the confluent pressure detection sensor 56. Also, the pressure of another of the first cooling solenoid valves 31a and the second cooling solenoid valves 31b is computed on the basis of the saturation temperature detected by the gas pipe temperature detection sensors 53. As illustrated in Fig. 10, in the case where the pressure difference ΔΡ is less than the pressure threshold ΔΡο (step ST3, No), the control returns to normal operation. On the other hand, in the case where the pressure difference ΔΡ is the pressure threshold ΔΡο or greater (step ST3, Yes), the control proceeds to step ST4.
[0107]
In this way, in the first modification, the gas state detector 80 includes the confluent pressure detection sensor 56 that detects the pressure of refrigerant circulating through the portion to which the liquid branch pipes 7b, 7c, and 7d and the first connecting pipe 6 are connected, and the gas pipe temperature detection sensors 53 that detect the temperature of refrigerant circulating through the gas branch pipes 6b, 6c, and 6d, and the determination unit 72 determines that refrigerant is generating flow noise in the case where the difference between the pressure of refrigerant detected by the confluent pressure detection sensor 56 and the pressure of refrigerant corresponding to the temperature detected by the gas pipe temperature detection sensors 53 is a pressure threshold or greater. The first modification likewise exhibits effects similar to Embodiment 1.
[0108] (Second modification)
Fig. 14 is a flowchart illustrating operations of the air conditioning apparatus 100 according to a second modification of Embodiment 1 of the present invention. Next, the second modification of Embodiment 1 will be described. In the first modification, the operation in step ST3 of Fig. 10 is different from Embodiment 1, and the determination unit 72 determines whether or not refrigerant is generating flow noise on the basis of a sub-cooling value on the outlet side of an indoor side heat exchanger 5 included in an indoor unit performing heating operation. [0109]
As illustrated in Fig. 14, the determination unit 72 determines whether or not the sub-cooling value SCa on the outlet side of an indoor side heat exchanger 5 included in an indoor unit performing heating operation is a sub-cooling threshold SCo or greater (step ST51). Note that the sub-cooling value SCa is computed on the basis of the saturation temperature of the indoor units during heating operation and the temperature of refrigerant detected by the liquid pipe temperature detection sensors 54. The saturation temperature of the indoor units during heating operation is computed on the basis of the pressure detected by the liquid outflow pressure detection sensor 25. As illustrated in Fig. 10, in the case where the sub-cooling value SCa is less than the sub-cooling threshold SCo (step ST3, No), since there is a small amount of liquid refrigerant, it is determined that the refrigerant is not generating flow noise, and the control returns to normal operation. On the other hand, in the case where the sub-cooling value SCa is the sub-cooling threshold SCo or greater (step ST3, Yes), since there is a large amount of liquid refrigerant, it is determined that the refrigerant is generating flow noise, and the control proceeds to step ST4. [0110]
In this way, in the second modification, the inflow side of the relay unit E is connected to the second connecting pipe 7 while the gas outflow side is connected to the heating solenoid valves 30 and the liquid outflow side is connected to the liquid branch pipes 7b, 7c, and 7d, and the gas-liquid separation apparatus 12 that separates the gas refrigerant and the liquid refrigerant. The gas state detector 80 includes the liquid outflow pressure detection sensor 25 that detects the pressure of refrigerant on the liquid outflow side of the gas-liquid separation apparatus 12, and the liquid pipe temperature detection sensors 54 that detect the temperature of refrigerant circulating through the liquid branch pipes 7b, 7c, and 7d. The determination unit 72 determines that refrigerant is generating flow noise in the case where a sub-cooling value on the outlet side of the indoor side heat exchangers 5 computed on the basis of the temperature of refrigerant corresponding to the pressure of refrigerant detected by the liquid outflow pressure detection sensor 25 and the temperature of refrigerant detected by the liquid pipe temperature detection sensors 54 is a sub-cooling threshold or greater. The second modification likewise exhibits effects similar to those in Embodiment 1.
[0111] (Third modification)
Fig. 15 is a flowchart illustrating operations of the air conditioning apparatus 100 according to a third modification of Embodiment 1 of the present invention. Next, the third modification of Embodiment 1 will be described. In the third modification, the operation in step ST3 of Fig. 10 is different from Embodiment 1, and the determination unit 72 determines whether or not refrigerant is generating flow noise on the basis of whether or not a stop threshold time has passed after the indoor side heat exchanger 5 included in an indoor unit performing heating operation stops. [0112]
As illustrated in Fig. 15, the determination unit 72 determines whether or not the elapsed time Ta since the stopping of an indoor side heat exchanger 5 included in an indoor unit performing heating operation is a threshold elapsed time To or less (step ST61). As illustrated in Fig. 10, in the case where the elapsed time Ta is the threshold elapsed time To or greater (step ST3, No), since the difference between the pressure of the first connecting pipe 6 and the pressure of the second connecting pipe 7 has become small, it is determined that the refrigerant is not generating flow noise, and the control returns to normal operation. On the other hand, in the case where the elapsed time Ta is less than the threshold elapsed time To (step ST3, Yes), since the difference between the pressure of the first connecting pipe 6 and the pressure of the second connecting pipe 7 is still large, it is determined that the refrigerant is generating flow noise, and the control proceeds to step ST4. [0113]
In this way, in the third modification, the determination unit 72 determines that refrigerant is generating flow noise during the period from the stopping of the indoor side heat exchangers 5 included in the indoor units B, C, and D performing heating operation until a stop threshold time passes. The third modification likewise exhibits effects similar to Embodiment 1.
Reference Signs List [0114] compressor 2 channel switching valve 3 heat source side heat exchange unit 4 accumulator 5 indoor side heat exchangers 6 first connecting pipe 6b, 6c, 6d gas branch pipes 7 second connecting pipe 7b, 7c, 7d liquid branch pipes 8 heat exchange unit 9 first flow rate control apparatus 10 first branching unit 11 second branching unit 12 gas-liquid separation apparatus 13 second flow rate control apparatus 14 first bypass pipe 15 third flow rate control apparatus 16 second heat exchange unit 18 discharge pressure detection sensor 19 first heat exchange unit 20 heat source side fan 25 liquid outflow pressure detection sensor 26 downstream liquid outflow pressure detection sensor 30 heating solenoid valves 31 cooling solenoid valves 31a first cooling solenoid valves 31b second cooling solenoid valves 32 third check valve 33 fourth check valve 34 fifth check valve 35 sixth check valve 40 heat source side channel adjustment unit 41 first heat source side heat exchanger 42 second heat source side heat exchanger 43 heat source side bypass channel 44 first solenoid opening and closing valve 45 second solenoid opening and closing valve 46 third solenoid opening and closing valve 47 fourth solenoid opening and closing valve 48 fifth solenoid opening and closing valve 50b first check valve 50c first check valve 50d first check valve 51 second bypass pipe 52b second check valve 52c second check valve 52d second check valve 53 gas pipe temperature detection sensors 54 liquid pipe temperature detection sensors 56 confluent pressure detection sensor 70 controller 71 valve control unit 72 determination unit 73 timing control unit 80 gas state detector 81 liquid state detector 100 air conditioning apparatus 110 first branching unit 111 second branching unit 112 gas-liquid separation apparatus 113 second flow rate control apparatus 115 third flow rate control apparatus 116 second heat exchange unit 119 first heat exchange unit 200 air conditioning apparatus A heat source unit B indoor unit C indoor unit D indoor unit E relay unit
Claims (1)
- CLAIMS [Claim 1]An air conditioning apparatus comprising:a heat source unit including a compressor, a channel switching valve, and heat source side heat exchanger;a plurality of indoor units that perform a cooling operation or a heating operation, with each indoor unit including a first flow rate control apparatus and an indoor side heat exchanger;a relay unit, connected to the heat source unit by a first connecting pipe and a second connecting pipe, and connected to each of the plurality of indoor units by a plurality of gas branch pipes and a plurality of liquid branch pipes, that distributes a refrigerant supplied from the heat source unit to the plurality of indoor units; and a controller configured to control an operation of the relay unit, wherein the relay unit includes a liquid state detector that detects a state of refrigerant flowing between the liquid branch pipes and the second connecting pipe, a gas-liquid separation apparatus that separates inflowing refrigerant into gas refrigerant and liquid refrigerant, having an inflow side being connected to the second connecting pipe, a gas outflow side being connected to the gas branch pipes, and a liquid outflow side being connected to the liquid branch pipes and the first connecting Pipe, a second flow rate control apparatus that is provided on the liquid outflow side of the gas-liquid separation apparatus, closed during the heating operation, open during the cooling operation, and adjusts a flow rate of the refrigerant, a third flow rate control apparatus that is provided on a downstream side of the second flow rate control apparatus and adjusts a flow rate of the refrigerant, cooling solenoid valves that are open during the cooling operation and closed during the heating operation, having one end being connected to the gas branch pipes and an other end being connected to the first connecting pipe, heating solenoid valves that are open during the heating operation and closed during the cooling operation, having one end being connected to the gas branch pipes and an other end being connected to the gas outflow side of the gas-liquid separation apparatus, and the controller includes a valve control unit that, when the heat source unit is switched from the heating operation to a defrosting operation, switches the channel switching valve, closes the heating solenoid valves, and opens the second flow rate control apparatus, a determination unit that, when refrigerant is circulated through the second flow rate control apparatus, determines whether or not the refrigerant flowing through the second flow rate control apparatus or the third flow rate control apparatus is generating a flow noise, based on the state of the refrigerant detected by the liquid state detector, and a timing control unit that, in a case where the determination unit determines that the refrigerant flowing through the second flow rate control apparatus or the third flow rate control apparatus is generating the flow noise, controls the valve control unit to successively open the heating solenoid valves and the cooling solenoid valves. [Claim 2]The air conditioning apparatus of claim 1, further comprising:a gas state detector that detects a state of the refrigerant flowing through the gas branch pipes, wherein the determination unit includes a function that, when refrigerant is circulated through the heating solenoid valves, determines whether or not the refrigerant flowing through the heating solenoid valves is generating the flow noise based on the state of the refrigerant detected by the gas state detector.[Claim 3]The air conditioning apparatus of claim 2, wherein in a case where the determination unit determines that the refrigerant flowing through the heating solenoid valves is not generating the flow noise, the timing control unit controls the valve control unit to open the heating solenoid valves, and when a time threshold is passed, open the cooling solenoid valves.[Claim 4]The air conditioning apparatus of claim 3, wherein the cooling solenoid valves is a plurality of cooling solenoid valves connected in parallel with each other, and in a case where the determination unit determines that the refrigerant flowing through the heating solenoid valves is not generating the flow noise, the timing control unit controls the valve control unit to open the heating solenoid valves, and when a time threshold is passed, open the plurality of cooling solenoid valves.[Claim 5]The air conditioning apparatus of claim 2, wherein in a case where the determination unit determines that the refrigerant flowing through the heating solenoid valves is generating the flow noise, the timing control unit controls the valve control unit to close the heating solenoid valves and also open the cooling solenoid valves, and when a time threshold is passed, open the heating solenoid valves.[Claim 6]The air conditioning apparatus of claim 5, wherein the timing control unit controls the valve control unit to successively open the heating solenoid valves connected to each of the gas branch pipes.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2016/072083 WO2018020621A1 (en) | 2016-07-27 | 2016-07-27 | Air conditioning device |
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| GB201819447D0 GB201819447D0 (en) | 2019-01-16 |
| GB2567332A true GB2567332A (en) | 2019-04-10 |
| GB2567332B GB2567332B (en) | 2021-04-21 |
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| GB1819447.2A Active GB2567332B (en) | 2016-07-27 | 2016-07-27 | Air conditioning apparatus |
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| JP (1) | JP6591071B2 (en) |
| GB (1) | GB2567332B (en) |
| WO (1) | WO2018020621A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4047289A4 (en) * | 2019-11-18 | 2022-12-21 | Daikin Industries, Ltd. | Intermediate unit for refrigeration device, and refrigeration device |
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|---|---|---|---|---|
| WO2021019686A1 (en) * | 2019-07-30 | 2021-02-04 | 三菱電機株式会社 | Air-conditioning device and control method therefor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08291951A (en) * | 1991-01-10 | 1996-11-05 | Mitsubishi Electric Corp | Air conditioner |
| JPH0942804A (en) * | 1995-07-25 | 1997-02-14 | Mitsubishi Electric Corp | Air conditioner |
| JP2007064510A (en) * | 2005-08-29 | 2007-03-15 | Daikin Ind Ltd | Air conditioner |
| WO2014106900A1 (en) * | 2013-01-07 | 2014-07-10 | 三菱電機株式会社 | Air conditioner device |
-
2016
- 2016-07-27 GB GB1819447.2A patent/GB2567332B/en active Active
- 2016-07-27 WO PCT/JP2016/072083 patent/WO2018020621A1/en active Application Filing
- 2016-07-27 JP JP2018530267A patent/JP6591071B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08291951A (en) * | 1991-01-10 | 1996-11-05 | Mitsubishi Electric Corp | Air conditioner |
| JPH0942804A (en) * | 1995-07-25 | 1997-02-14 | Mitsubishi Electric Corp | Air conditioner |
| JP2007064510A (en) * | 2005-08-29 | 2007-03-15 | Daikin Ind Ltd | Air conditioner |
| WO2014106900A1 (en) * | 2013-01-07 | 2014-07-10 | 三菱電機株式会社 | Air conditioner device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4047289A4 (en) * | 2019-11-18 | 2022-12-21 | Daikin Industries, Ltd. | Intermediate unit for refrigeration device, and refrigeration device |
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| Publication number | Publication date |
|---|---|
| JPWO2018020621A1 (en) | 2019-02-28 |
| JP6591071B2 (en) | 2019-10-16 |
| GB2567332B (en) | 2021-04-21 |
| GB201819447D0 (en) | 2019-01-16 |
| WO2018020621A1 (en) | 2018-02-01 |
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