EP2902726A1 - Combined air-conditioning and hot-water supply system - Google Patents
Combined air-conditioning and hot-water supply system Download PDFInfo
- Publication number
- EP2902726A1 EP2902726A1 EP12885435.3A EP12885435A EP2902726A1 EP 2902726 A1 EP2902726 A1 EP 2902726A1 EP 12885435 A EP12885435 A EP 12885435A EP 2902726 A1 EP2902726 A1 EP 2902726A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- refrigerant
- unit
- water supply
- hot water
- heat exchanger
- 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.)
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 272
- 238000004378 air conditioning Methods 0.000 title claims abstract description 35
- 239000003507 refrigerant Substances 0.000 claims abstract description 272
- 239000007788 liquid Substances 0.000 claims abstract description 106
- 238000007710 freezing Methods 0.000 claims abstract description 44
- 230000008014 freezing Effects 0.000 claims abstract description 44
- 238000001816 cooling Methods 0.000 claims description 50
- 238000010438 heat treatment Methods 0.000 claims description 47
- 238000000034 method Methods 0.000 description 25
- 239000012071 phase Substances 0.000 description 25
- 239000000203 mixture Substances 0.000 description 10
- 230000002265 prevention Effects 0.000 description 9
- 230000007423 decrease Effects 0.000 description 7
- 238000007664 blowing Methods 0.000 description 6
- VOPWNXZWBYDODV-UHFFFAOYSA-N Chlorodifluoromethane Chemical compound FC(F)Cl VOPWNXZWBYDODV-UHFFFAOYSA-N 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 4
- 238000005057 refrigeration Methods 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- 230000002528 anti-freeze Effects 0.000 description 3
- OHMHBGPWCHTMQE-UHFFFAOYSA-N 2,2-dichloro-1,1,1-trifluoroethane Chemical compound FC(F)(F)C(Cl)Cl OHMHBGPWCHTMQE-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 108010053481 Antifreeze Proteins Proteins 0.000 description 2
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical compound CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000012267 brine Substances 0.000 description 2
- RWRIWBAIICGTTQ-UHFFFAOYSA-N difluoromethane Chemical compound FCF RWRIWBAIICGTTQ-UHFFFAOYSA-N 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000011555 saturated liquid Substances 0.000 description 2
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 2
- UJPMYEOUBPIPHQ-UHFFFAOYSA-N 1,1,1-trifluoroethane Chemical compound CC(F)(F)F UJPMYEOUBPIPHQ-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- FRYDSOYOHWGSMD-UHFFFAOYSA-N [C].O Chemical compound [C].O FRYDSOYOHWGSMD-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Images
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
- 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
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/006—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass for preventing frost
-
- 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
- F25B2313/003—Indoor unit with water as a heat sink or heat source
-
- 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
-
- 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
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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
- 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
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/031—Sensor arrangements
- F25B2313/0315—Temperature sensors near the outdoor 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
- F25B2500/00—Problems to be solved
- F25B2500/06—Damage
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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
- 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
-
- 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
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21151—Temperatures of a compressor or the drive means therefor at the suction side of the compressor
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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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21152—Temperatures of a compressor or the drive means therefor at the discharge side of the compressor
Definitions
- the present invention relates to a combined air-conditioning and hot water supply system capable of performing air-conditioning and hot water supply by using a heat pump cycle.
- Combined air-conditioning and hot water supply systems have been proposed which use a heat pump cycle (refrigeration cycle) to exchange heat with a heat source such as air or water, and supply the heat to a plurality of indoor devices (indoor units) and a plurality of hot water supply devices (hot water supply units) (see, for example, Patent Literature 1).
- a branch unit is connected to a heat source unit.
- At least one indoor unit and at least one hot water supply unit are connected to the branch unit. Consequently, air-conditioning and hot water supply can be executed simultaneously by use of a single heat source.
- Patent Literature 1 International Publication No. WO2009/098751 (page 1, Fig. 1 , etc.)
- the present invention has been made to address the above-mentioned problem, and accordingly it is an object of the present invention to provide a combined air-conditioning and hot water supply system that makes it possible to prevent freezing in the refrigerant-water heat exchanger in the hot water supply unit.
- a combined air-conditioning and hot water supply system includes a refrigerant circuit and a control processing device.
- the refrigerant circuit is formed by connecting, by pipes, at least one heat source unit including a compressor and a heat source-side heat exchanger, at least one indoor unit including an indoor-side heat exchanger and an indoor-side expansion device, at least one hot water supply unit including a refrigerant-water heat exchanger and a hot water supply-side expansion device, and a branch unit including a gas-liquid separator and a refrigerant flow control device.
- the gas-liquid separator supplies a gaseous refrigerant to the indoor unit and/or the hot water supply unit which heats a target with which the gaseous refrigerant exchanges heat, and supplies a liquid refrigerant to the indoor unit and/or the hot water supply unit which cools a target with which the liquid refrigerant exchanges heat.
- the refrigerant flow control device controls passage of a refrigerant to the indoor unit and the hot water supply unit.
- the control processing device performs a control that, while the hot water supply unit is stopped, increases a pressure in a refrigerant-side flow path in the refrigerant-water heat exchanger, if the control processing device determines that there is a possibility of freezing of water in a water-side flow path in the refrigerant-water heat exchanger.
- the control processing device determines that there is a possibility of freezing of water in the water-side flow path in the refrigerant-water heat exchanger, the control processing device increases the pressure in the refrigerant-side flow path in the refrigerant-water heat exchanger, thereby preventing freezing of water in the refrigerant-water heat exchanger.
- Fig. 1 illustrates an example of the configuration of a combined air-conditioning and hot water supply system 000 according to Embodiment 1 of the present invention.
- the configuration or the like of the system will be described with reference to Fig. 1 .
- the combined air-conditioning and hot water supply system 000 according to Embodiment 1 which is installed in, for example, buildings, apartments, or hotels, has a refrigerant circuit formed by connecting apparatuses by pipes, and is capable of supplying heat (heating energy/cooling energy) to an air conditioning load and a hot water supply load simultaneously by using a heat pump cycle (refrigeration cycle).
- the combined air-conditioning and hot water supply system 000 at least has at least one heat source unit (outdoor device) 110, at least one branch unit (relay device) 210, at least one indoor unit (indoor device) 310, and a hot water supply unit 410.
- the indoor unit 310 and the hot water supply unit 410 which serve as load units, are connected to the heat source unit 110 in a parallel fashion via the branch unit 210.
- the indoor unit 310 and the hot water supply unit 410 are allowed to exert the function of executing space cooling (to be also referred to simply as “cooling” hereinafter) or space heating (to be also referred to simply as “heating” hereinafter) and the function of supplying hot water or cold water, respectively. While Fig. 1 illustrates a case in which a single indoor unit 310 and a single hot water supply unit 410 are connected to the branch unit 210, this is not intended to limit the number of these units to be connected.
- the heat source unit 110 and the branch unit 210 are connected to each other by a high pressure main pipe 001 and a low pressure main pipe 002 that are refrigerant pipes, thus allowing refrigerant to flow.
- the branch unit 210 and the indoor unit 310 are connected to each other by gas branch pipes 003a and 003b that are refrigerant pipes.
- the branch unit 210 and the hot water supply unit 410 are connected to each other by liquid branch pipes 004a and 004b that are refrigerant pipes.
- Refrigerants used in the combined air-conditioning and hot water supply system 000 include, for example, zeotropic refrigerant mixtures, near-azeotropic refrigerant mixtures, and single-component refrigerants.
- Zeotropic refrigerant mixtures are available in various kinds such as R407C (R32/R125/R134a), which is a hydrofluorocarbon (HFC) refrigerant. Accordingly, a refrigerant suited for the intended use or purpose of the combined air-conditioning and hot water supply system 000 may be used.
- Zeotropic refrigerant mixtures are mixtures made up of refrigerants with different boiling points, and thus have a characteristic such that the composition ratios of liquid-phase and gas-phase refrigerants differ from each other.
- near-azeotropic refrigerant mixtures include R410A (R32/R125) and R404A (R125/R143a/R134a) that are HFC refrigerants.
- near-azeotropic refrigerant mixtures have such a characteristic that their operating pressure is approximately 1.6 times that of R22.
- single-component refrigerants include R22, which is a hydrochlorofluorocarbon (HCFC) refrigerant, and R134a, which is a HFC refrigerant.
- HCFC hydrochlorofluorocarbon
- R134a which is a HFC refrigerant.
- Single-component refrigerants are not mixtures, and thus have the characteristic of being easy to handle.
- natural refrigerants such as carbon hydrate, propane, isobutene, and ammonia may also be used.
- R22 denotes chlorodifluoromethane
- R32 denotes difluoromethane
- R125 denotes pentafluoromethane
- R134a denotes 1,1,1,2-tetrafluoromethane
- R143a denotes 1,1,1-trifluoroethane.
- the heat source unit 110 has the function of sending refrigerant to the indoor unit 310 and the hot water supply unit 410 via the branch unit 210 to supply heating energy or cooling energy to a load.
- the heat source unit 110 according to Embodiment 1 includes a compressor 111, a flow switching valve 112, a heat source-side heat exchanger 113, and an accumulator (liquid reservoir) 115, which are connected in series as illustrated in Fig. 1 .
- the compressor 111 compresses a sucked refrigerant and discharges the refrigerant in a high-temperature/high-pressure state.
- the type of the compressor is not particularly limited.
- compressors of various types, such as reciprocating, rotary, scroll, and screw types may be used as the compressor 111.
- the compressor 111 preferably includes a type of compressor whose rotation speed can be variably controlled by an inverter.
- the heat source-side heat exchanger 113 functions as a radiator (condenser) or an evaporator.
- the heat source-side heat exchanger 113 exchanges heat between the refrigerant and air, with which the refrigerant is to exchange heat, thereby causing the refrigerant to condense and liquefy or evaporate and gasify.
- the heat source-side heat exchanger 113 is sometimes used as a radiator.
- the refrigerant in gaseous form (gaseous refrigerant) from the compressor 111 is only partially condensed, resulting in a refrigerant in a two-phase state that is made up of a gaseous refrigerant and a refrigerant in liquid form (liquid refrigerant).
- heat is exchanged between the air from an air-blowing device 114 and refrigerant.
- the air-blowing device 114 which includes a fan or the like, supplies the heat source-side heat exchanger 113 with the air with which refrigerant is to exchange heat.
- the accumulator 115 which is arranged on the suction side of the compressor 111, is a container for storing excess refrigerant.
- check valve group regulates the flow of refrigerant so that refrigerant flows through the high pressure main pipe 001 so as to exit the heat source unit 110 and enter the branch unit 210, and refrigerant flows through the low pressure main pipe 002 so as to exit the branch unit 210 and enter the heat source unit 110.
- a discharge pressure sensor 117H detects the discharge pressure of refrigerant.
- a suction pressure sensor 117L detects the suction pressure of refrigerant.
- a discharge temperature sensor 118H detects the discharge temperature of refrigerant.
- a suction temperature sensor 118L detects the suction temperature of refrigerant.
- a heat-source heat exchanger temperature sensor 119a detects the temperature of refrigerant that enters and exits the heat source-side heat exchanger 113.
- An outside air temperature sensor 119b detects the temperature of the outside air introduced into the heat source unit 110.
- a heat-source control processing device 120 controls various actuators on the basis of temperatures, pressures, and the like detected by these various sensors.
- the branch unit 210 regulates the flow of refrigerant between load units (the indoor unit 310 and the hot water supply unit 410), and the heat source unit 110. Further, the branch unit 210 causes each of an indoor heat exchanger 311 of the indoor unit 310, and a refrigerant-water heat exchanger 411 of the hot water supply unit 410 to function as a radiator or an evaporator.
- the branch unit 210 at least has a gas-liquid separator 211, a solenoid valve 213a, a solenoid valve 213b, a liquid refrigerant expansion device 212, a bypass expansion device 214, and a branch pressure sensor 215 that is used to detect an intermediate pressure.
- the solenoid valve 213a which serves as a refrigerant flow control device, connects to each of the low pressure main pipe 002, the gas branch pipe 003a, and the gas-liquid separator 211.
- the solenoid valve 213a switches the flow path of refrigerant entering and exiting the indoor unit 310 on the basis of an instruction from a branch control processing device 220, thereby controlling passage of refrigerant.
- the solenoid valve 213b which serves as a hot-water-supply-unit flow switching device, connects to each of the low pressure main pipe 002, the gas branch pipe 003a, and the gas-liquid separator 211.
- the solenoid valve 213b switches the flow path of refrigerant entering and exiting the hot water supply unit 410 on the basis of an instruction from the branch control processing device 220, thereby controlling passage of refrigerant.
- the number of solenoid valves 213 is not particularly limited but may be determined as required. While the solenoid valve 213 includes a combination of two two-way solenoid valves in Fig. 1 , the solenoid valve 213 may be include a combination of three-way valves or the like.
- the gas-liquid separator 211 separates the refrigerant that has entered the gas-liquid separator 211 from the high pressure main pipe 001 into a gaseous refrigerant and a liquid refrigerant.
- the gaseous refrigerant flows toward the solenoid valve 213 (213a and 213b).
- the liquid refrigerant separated by the gas-liquid separator 211 flows toward the liquid refrigerant expansion device 212.
- the liquid refrigerant expansion device 212 reduces the pressure of the liquid refrigerant flowing from the gas-liquid separator 211, causing the liquid refrigerant to expand.
- the bypass expansion device 214 regulates, for example, the pressure and amount of refrigerant that exits each of the indoor unit 310 and the hot water supply unit 410 and flows to the low pressure main pipe 002.
- Each of the liquid refrigerant expansion device 212 and the bypass expansion device 214 preferably includes, for example, flow control means based on an electronic expansion valve whose opening degree can be varied by fine control, or inexpensive refrigerant flow control means such as a capillary.
- the branch pressure sensor 215 is a sensor that detects intermediate pressure.
- the branch unit 210 has the following three pressure ranges: the pressure of refrigerant that enters the branch unit 210 from the heat source unit 110 (high pressure); the pressure of refrigerant that enters the heat source unit 110 (low pressure); and the intermediate pressure between the high pressure and the low pressure.
- the intermediate pressure can be changed by changing the opening degrees of the liquid refrigerant expansion device 212 and the bypass expansion device 214.
- a change in intermediate pressure changes the ratio between the flow of refrigerant passed to the space heating (hot water supply) side and the flow of refrigerant passed to the space cooling (cooling) side, causing the ratio between space heating (hot water supply) and space cooling (cooling) capacities to change.
- the branch control processing device 220 controls the opening degrees of the liquid refrigerant expansion device 212 and the bypass expansion device 214 on the basis of the pressure detected by the branch pressure sensor 215.
- the indoor unit 310 has the function of drawing heating energy or cooling energy from the refrigerant delivered from the heat source unit 110, and supplying the heating energy or the cooling energy to the air conditioning load.
- the indoor unit 310 according to Embodiment 1 includes an indoor-unit expansion device 312 and the indoor heat exchanger 311, which are connected in series as illustrated in Fig. 1 .
- an air-blowing device such as a fan for supplying air to the indoor heat exchanger 311 may be provided near the indoor heat exchanger 311.
- the indoor heat exchanger 311 functions as a radiator (condenser) in the heating operation, and functions as an evaporator in the cooling operation.
- the indoor heat exchanger 311 exchanges heat between the refrigerant and the air in an air-conditioned space, thereby causing the refrigerant to condense and liquefy or evaporate and gasify.
- the pressure reducing valve preferably includes, for example, flow control means based on an electronic expansion valve whose opening degree can be varied by fine control, or inexpensive refrigerant flow control means such as a capillary.
- An indoor-unit gas pipe temperature sensor 313G and an indoor-unit liquid pipe temperature sensor 313L are installed at positions in the pipe where refrigerant enters and exits the indoor heat exchanger 311, respectively.
- An indoor air temperature sensor 314 detects the temperature of at least one of the air sucked into the indoor heat exchanger 311 and the air expelled from the indoor heat exchanger 311.
- an indoor control processing device 320 controls the opening degree of the indoor-unit expansion device 312 to control the flow rate of refrigerant.
- the hot water supply unit 410 has the function of drawing heating energy or cooling energy from the refrigerant delivered from the heat source unit 110, and supplying the heating energy or the cooling energy to the hot water supply load.
- the hot water supply unit 410 according to Embodiment 1 includes a hot-water-supply-unit expansion device 412 and the refrigerant-water heat exchanger 411, which are connected in series as illustrated in Fig. 1 .
- the refrigerant-water heat exchanger 411 functions as a radiator (condenser) or an evaporator.
- the refrigerant-water heat exchanger 411 exchanges heat between the refrigerant and the water that passes through a water pipe 010, thereby causing the refrigerant to condense and liquefy or evaporate and gasify.
- the hot-water-supply-unit expansion device 412 which includes, for example, a pressure reducing valve (expansion valve), causes refrigerant to expand by reducing its pressure.
- the hot-water-supply-unit expansion device 412 preferably includes, for example, flow control means or refrigerant flow control means.
- a hot-water-supply-unit gas pipe temperature sensor 413G and a hot-water-supply-unit liquid pipe temperature sensor 413L are installed at positions in the pipe where refrigerant enters and exits the refrigerant-water heat exchanger 411, respectively. Further, an inlet water temperature sensor 4141 and an outlet water temperature sensor 4140 are installed at positions in the pipe where water enters and exits the refrigerant-water heat exchanger 411. On the basis of temperatures detected by these temperature sensors, a hot-water-supply control processing device 420 controls the opening degree of the hot-water-supply-unit expansion device 412 to control the flow rate of refrigerant. Further, it is preferable to provide, for example, a sensor that detects the temperature of water stored in a hot water storage tank (not illustrated).
- the water pipe 010 is a pipe that forms a water circuit by connecting a pump (not illustrated), the hot water storage tank, the refrigerant-water heat exchanger 411, and the like. In the water circuit, water that has been heated or cooled through heat exchange in the refrigerant-water heat exchanger 411 circulates.
- the water pipe 010 preferably includes a copper pipe, a stainless pipe, a steel pipe, a vinyl chloride pipe, or the like. While water is circulated in the water circuit in Embodiment 1, for example, an antifreeze may be circulated in the water circuit.
- the heat source unit 110, the branch unit 210, the indoor unit 310, and the hot water supply unit 410 have the heat-source control processing device 120, the branch control processing device 220, the indoor control processing device 320, and the hot-water-supply control processing device 420, respectively.
- each of the control processing devices is provided in the corresponding one of these units, these control processing devices may be integrated into a single or a plurality of control processing devices.
- the heat-source control processing device 120 provided in the heat source unit 110 controls the pressure and temperature states of refrigerant in the combined air-conditioning and hot water supply system 000, for example. Specifically, for example, the heat-source control processing device 120 executes processing such as control of the driving frequency of the compressor 111, control of the fan rotation speed of the air-blowing device 114, and switching of the flow switching valve 112.
- the branch control processing device 220 provided in the branch unit 210 executes processing such as control of the opening degrees of the liquid refrigerant expansion device 212 and the bypass expansion device 214, and opening and closing control of the solenoid valve 213 (the solenoid valve 213a and the solenoid valve 213b).
- the indoor control processing device 320 provided in the indoor unit 310 controls various apparatuses to provide air conditioning for an air-conditioned space.
- the indoor control processing device 320 controls the degree of superheat of refrigerant when cooling is performed in the indoor unit 310, and controls the degree of subcooling of refrigerant when heating is performed in the indoor unit 310.
- the indoor control processing device 320 executes processing such as control of the fan rotation speed of an air-blowing device (not illustrated), and control of the opening degree of the indoor-unit expansion device 312.
- the hot-water-supply control processing device 420 of the hot water supply unit 410 has the function of controlling the degree of superheat when cooling is executed by the hot water supply unit 410, and the degree of subcooling when heating (hot water supply) is executed by the hot water supply unit 410, on the basis of, for example, temperatures obtained from the hot-water-supply-unit gas pipe temperature sensor 413G and the hot-water-supply-unit liquid pipe temperature sensor 413L.
- the hot-water-supply control processing device 420 has the function of varying the area of heat exchange in the refrigerant-water heat exchanger 411, or controlling the opening degree of the hot-water-supply-unit expansion device 412.
- the hot-water-supply control processing device 420 executes a process that prevents freezing of the water-side flow path in the refrigerant-water heat exchanger 411 while the hot water supply unit 410 is stopped. It is assumed that the hot-water-supply control processing device 420 has clock means (timer) to execute this process.
- Embodiment 1 There are four operation modes that can be executed by the combined air-conditioning and hot water supply system 000 according to Embodiment 1.
- cooling main operation mode in which, when the indoor unit 310 that is executing space heating and the indoor unit 310 that is executing space cooling are mixed, and cooling or hot water supply is executed in the hot water supply unit 410, the space cooling/cooling load is greater.
- heating main operation mode in which, when the indoor unit 310 that is executing space heating and the indoor unit 310 that is executing space cooling are mixed, and cooling or hot water supply is executed in the hot water supply unit 410, the space heating/hot water supply load is greater.
- the cooling main operation mode and the heating main operation mode are switched so as to maximize capacity or efficiency by, for example, comparing the condensing temperature and evaporating temperature of refrigerant in the combined air-conditioning and hot water supply system 000 with target values set within the heat source unit 110.
- Fig. 2 illustrates the flow of refrigerant in the cooling operation mode.
- a description will be given of the flow of refrigerant and the details of operation in the cooling operation mode when all of the indoor units 310 that are running are in space cooling operation, and the hot water supply unit 410 is in the cooling operation.
- a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then enters the heat source-side heat exchanger 113 via the flow switching valve 112.
- the high-pressure gaseous refrigerant that has entered the heat source-side heat exchanger 113 condenses into a high-pressure liquid refrigerant by exchanging heat with the air supplied to the heat source-side heat exchanger 113, and then exits the heat source-side heat exchanger 113.
- the high-pressure liquid refrigerant that has exited the heat source-side heat exchanger 113 exits the heat source unit 110 via the check valve group 116. Then, the high-pressure liquid refrigerant flows through the high pressure main pipe 001, and enters the branch unit 210.
- the high-pressure liquid refrigerant that has entered the branch unit 210 from the high pressure main pipe 001 passes through the gas-liquid separator 211 and the liquid refrigerant expansion device 212, and exits the branch unit 210.
- the refrigerant that has exited the branch unit 210 flows through the liquid branch pipe 004, and enters the indoor unit 310 and the hot water supply unit 410.
- the indoor unit 310 the refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the indoor-unit expansion device 312, and flows to the indoor heat exchanger 311.
- the low-pressure two-phase refrigerant or the low-pressure liquid refrigerant that has entered the indoor heat exchanger 311 evaporates in the indoor heat exchanger 311 into a low-pressure gaseous refrigerant, and exits the indoor heat exchanger 311.
- the refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the hot-water-supply-unit expansion device 412, and flows to the refrigerant-water heat exchanger 411.
- the low-pressure two-phase refrigerant or the low-pressure liquid refrigerant that has entered the refrigerant-water heat exchanger 411 evaporates in the refrigerant-water heat exchanger 411 into a low-pressure gaseous refrigerant, and exits the refrigerant-water heat exchanger 411.
- the low-pressure gaseous refrigerant that has flown to the low pressure main pipe 002 exits the branch unit 210, and then enters the heat source unit 110.
- the low-pressure gaseous refrigerant that has entered the heat source unit 110 is sucked into the compressor 111 again via the check valve group 116, the flow switching valve 112, and the accumulator 115.
- Fig. 3 illustrates the flow of refrigerant in the heating operation mode.
- a description will be given of the flow of refrigerant and the details of operation in the heating operation mode when all of the indoor units 310 that are running are in space heating operation, and the hot water supply unit 410 is in the hot water supply operation.
- a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then exits the heat source unit 110 via the flow switching valve 112 and the check valve group 116. Then, after passing through the high pressure main pipe 001, the high temperature/high pressure gaseous refrigerant enters the branch unit 210.
- the high-pressure gaseous refrigerant that has entered the branch unit 210 from the high pressure main pipe 001 passes through the gas-liquid separator 211 and the solenoid valve 213, and exits the branch unit 210. Then, the high-pressure gaseous refrigerant flows through the gas branch pipe 003, and enters the indoor unit 310 and the hot water supply unit 410.
- the high-pressure gaseous refrigerant that has entered the indoor unit 310 enters the indoor heat exchanger 311, and is condensed in the indoor heat exchanger 311. Further, in the indoor-unit expansion device 312, the resulting refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure, and exits the indoor unit 310. Then, the resulting refrigerant flows through the liquid branch pipe 004a, and enters the branch unit 210.
- the high-pressure gaseous refrigerant that has entered the hot water supply unit 410 enters the refrigerant-water heat exchanger 411.
- the high-pressure gaseous refrigerant is condensed into a high-pressure liquid refrigerant, and then exits the refrigerant-water heat exchanger 411.
- the high-pressure liquid refrigerant that has exited the refrigerant-water heat exchanger 411 turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the hot-water-supply-unit expansion device 412, and exits the hot water supply unit 410.
- the resulting refrigerant flows through the liquid branch pipe 004b, and enters the branch unit 210.
- Fig. 4 illustrates the flow of refrigerant in the cooling main operation mode.
- the indoor unit 310 is executing space cooling and the hot water supply unit 410 is executing hot water supply, and the space cooling load is greater than the space heating load.
- a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then enters the heat source-side heat exchanger 113 via the flow switching valve 112.
- the high-pressure gaseous refrigerant that has entered the heat source-side heat exchanger 113 condenses into a two-phase liquid-gas refrigerant at high pressure by exchanging heat with the air supplied to the heat source-side heat exchanger 113, and then exits the heat source-side heat exchanger 113.
- the high-pressure two-phase refrigerant that has exited the heat source-side heat exchanger 113 exits the heat source unit 110 via the check valve group 116. Then, the high-pressure two-phase refrigerant flows through the high pressure main pipe 001, and enters the branch unit 210.
- the high-pressure two-phase refrigerant that has entered the branch unit 210 from the high pressure main pipe 001 is separated in the gas-liquid separator 211 into high-pressure saturated gas and high-pressure saturated liquid.
- the high-pressure saturated gas separated by the gas-liquid separator 211 exits the branch unit 210 via the solenoid valve 213b, and passes through the gas branch pipe 003b to enter the hot water supply unit 410.
- the refrigerant that has entered the hot water supply unit 410 is condensed in the refrigerant-water heat exchanger 411 into a high-pressure liquid refrigerant, and then exits the refrigerant-water heat exchanger 411.
- the high-pressure liquid refrigerant that has exited the refrigerant-water heat exchanger 411 turns into a two-phase liquid-gas refrigerant at intermediate pressure or a liquid refrigerant at intermediate pressure in the hot-water-supply-unit expansion device 412, and exits the hot water supply unit 410. Then, the resulting refrigerant flows through the liquid branch pipe 004b, and enters the branch unit 210.
- the refrigerant that has entered the branch unit 210 is re-used when cooling is performed by the indoor unit 310.
- the high-pressure saturated liquid separated by the gas-liquid separator 211 passes through the liquid refrigerant expansion device 212, and merges with the refrigerant that has flown from the hot water supply unit 410. Then, after exiting the branch unit 210, the resulting refrigerant flows through the liquid branch pipe 004a, and enters the indoor unit 310. In the indoor unit 310, the refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the indoor-unit expansion device 312, and flows to the indoor heat exchanger 311.
- the low-pressure two-phase refrigerant or the low-pressure liquid refrigerant that has entered the indoor heat exchanger 311 evaporates in the indoor heat exchanger 311 into a low-pressure gaseous refrigerant, and exits the indoor heat exchanger 311.
- the low-pressure gaseous refrigerant that has exited the indoor heat exchanger 311 flows through the gas branch pipe 003a, and enters the branch unit 210.
- the pressure in the liquid pipe rises. If, for example, there is any indoor unit 310 that is executing heating at this time, the pressure difference with respect to the liquid pipe decreases, which causes a decrease in the amount of refrigerant that flows to the indoor unit 310 that is executing heating, leading to a decrease in heating capacity. Accordingly, to release liquid accumulating in the liquid line, the bypass expansion device 214 is opened to an appropriate degree, thus allowing the liquid accumulating in the liquid line to pass to the low pressure main pipe 002 to regulate the pressure in the liquid line.
- the refrigerant that has exited the branch unit 210 turns into a low-pressure two-phase refrigerant as the low-pressure gaseous refrigerant that has entered from the indoor unit 310 and the liquid refrigerant that has entered from the bypass expansion device 214 are mixed.
- the low-pressure two-phase refrigerant that has entered the branch unit 210 passes through the solenoid valve 213a, and exits the branch unit 210.
- the low-pressure two-phase refrigerant flows through the low pressure main pipe 002, and enters the heat source unit 110.
- the low-pressure two-phase refrigerant that has entered the heat source unit 110 is sucked into the compressor 111 again via the check valve group 116, the flow switching valve 112, and the accumulator 115.
- Fig. 5 illustrates the flow of refrigerant in the heating main operation mode.
- the indoor unit 310 is executing space heating and the hot water supply unit 410 is executing cooling, and the space heating load is greater than the space cooling load.
- a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then exits the heat source unit 110 via the flow switching valve 112 and the check valve group 116. Then, the high temperature/high pressure gaseous refrigerant passes through the high pressure main pipe 001, and enters the branch unit 210.
- the high-pressure gaseous refrigerant that has entered the branch unit 210 from the high pressure main pipe 001 passes through the gas-liquid separator 211 and the solenoid valve 213a, and exits the branch unit 210. Then, the high-pressure gaseous refrigerant flows through the gas branch pipe 003a, and enters the indoor unit 310.
- the high-pressure gaseous refrigerant that has entered the indoor unit 310 enters the indoor heat exchanger 311, and is condensed in the indoor heat exchanger 311. Further, in the indoor-unit expansion device 312, the refrigerant turns into a two-phase liquid-gas refrigerant at intermediate pressure, or a liquid refrigerant at intermediate pressure, and exits the indoor unit 310. Then, the resulting refrigerant flows through the liquid branch pipe 004a, and enters the branch unit 210.
- the intermediate-pressure refrigerant that has entered the branch unit 210 exits the branch unit 210, and flows through the liquid branch pipe 004b to enter the hot water supply unit 410.
- the refrigerant that has entered the hot water supply unit 410 turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the hot-water-supply-unit expansion device 412, and enters the refrigerant-water heat exchanger 411.
- the low-pressure liquid refrigerant that has entered the refrigerant-water heat exchanger 411 evaporates into a low-pressure gaseous refrigerant, and exits the hot water supply unit 410. Then, the low-pressure gaseous refrigerant flows through the liquid branch pipe 004b, and enters the branch unit 210.
- the bypass expansion device 214 is opened to an appropriate degree to regulate the pressure in the liquid line.
- the low-pressure gaseous refrigerant that has entered from the hot water supply unit 410 and the liquid refrigerant that has entered from the bypass expansion device 214 are mixed, resulting in a low-pressure two-phase refrigerant.
- the low-pressure two-phase refrigerant passes through the solenoid valve 213a, and exits the branch unit 210. Then, the low-pressure two-phase refrigerant flows through the low pressure main pipe 002, and enters the heat source unit 110. The low-pressure two-phase refrigerant that has entered the heat source unit 110 is sucked into the compressor 111 again via the check valve group 116, the flow switching valve 112, and the accumulator 115.
- Fig. 6 illustrates the procedure of a freezing prevention process according to Embodiment 1 of the present invention.
- a freezing prevention process for a water circuit (the refrigerant-water heat exchanger 411) according to Embodiment 1 will be described. This process is executed while, for example, heating or cooling of water is stopped in the hot water supply unit 410.
- the hot-water-supply control processing device 420 starts a control according to the freezing prevention process (S01i). At this time, the solenoid valve 213b is in a closed state, and the opening degree of the hot-water-supply-unit expansion device 412 is basically zero.
- temperatures detected by various temperature sensors (the hot-water-supply-unit gas pipe temperature sensor 413G, the hot-water-supply-unit liquid pipe temperature sensor 413L, the inlet water temperature sensor 414I, and the outlet water temperature sensor 4140) provided in the hot water supply unit 410 are read (S02i).
- the refrigerant pipe temperature detected by at least one of the hot-water-supply-unit gas pipe temperature sensor 413G and the hot-water-supply-unit liquid pipe temperature sensor 413L is less than a water circuit freezing temperature TCOLD (refrigerant pipe temperature ⁇ TCOLD) (S03i). For this determination, it may be determined whether one of the refrigerant pipe temperatures detected by the hot-water-supply-unit gas pipe temperature sensor 413G and the hot-water-supply-unit liquid pipe temperature sensor 413L is less than the water circuit freezing temperature TCOLD, or it may be determined whether both of the refrigerant pipe temperatures are less than the water circuit freezing temperature TCOLD. If it is determined in S03i that the refrigerant pipe temperature is not less than the water circuit freezing temperature TCOLD (the refrigerant pipe temperature is higher than or equal to the water circuit freezing temperature TCOLD), the process is ended (S08i).
- Increasing the opening degree makes it possible to reduce pressure loss in the pipe between the branch unit 210 and the hot water supply unit 410.
- the pressure of refrigerant in the refrigerant-water heat exchanger 411 rises from a low pressure to an intermediate pressure. This rise in pressure causes a rise in refrigerant pipe temperature, making it possible to avoid breakage of the heat exchanger due to freezing of the water circuit portion of the refrigerant-water heat exchanger 411 in the hot water supply unit 410.
- opening the hot-water-supply-unit expansion device 412 to any given opening degree does not cause an instantaneous rise in refrigerant pipe temperature. Accordingly, it is determined whether any given set time or more has elapsed since the hot-water-supply-unit expansion device 412 is opened (S05i). The opening degree is maintained in the current state until it is determined that the elapsed time has reached the set time or more (S07i). If it is determined that the set time has elapsed, the opening degree of the hot-water-supply-unit expansion device 412 is reset to the original state (S06i), and the process is ended (S08i). The above process is executed while heating or cooling of water is stopped in the hot water supply unit 410.
- the hot water supply unit 410 is stopped, if, for example, the refrigerant leakage or the like due to incomplete closure of the opening degree of the hot-water-supply-unit expansion device 412 causes the refrigerant temperature in the refrigerant-water heat exchanger 411 to decrease, and it is determined as a result that the refrigerant pipe temperature is less than the water circuit freezing temperature TCOLD, the hot-water-supply-unit expansion device 412 is opened to the opening degree A to increase the pressure, and hence the temperature, at the refrigerant side in the refrigerant-water heat exchanger 411. Therefore, freezing of water in the refrigerant-water heat exchanger 411 can be prevented. As a result, breakage of the refrigerant-water heat exchanger 411 can be prevented.
- Fig. 7 illustrates the procedure of a freezing prevention process according to Embodiment 2 of the present invention.
- the hot-water-supply-unit expansion device 412 is closed upon elapse of a set time on the basis of S05i, S06i, and S07i.
- Fig. 8 illustrates the procedure of a freezing prevention process according to Embodiment 3 of the present invention.
- Embodiments 1 and 2 mentioned above when the temperature of water in the refrigerant-water heat exchanger 411 decreases, the opening degree of the hot-water-supply-unit expansion device 412 is regulated to prevent freezing. In Embodiment 3, freezing is prevented by switching the solenoid valve 213b.
- the hot-water-supply control processing device 420 starts a control according to the freezing prevention process (S11i). At this time, the solenoid valve 213b is in a closed state, and the opening degree of the hot-water-supply-unit expansion device 412 is basically zero.
- temperatures detected by various temperature sensors (the hot-water-supply-unit gas pipe temperature sensor 413G, the hot-water-supply-unit liquid pipe temperature sensor 413L, the inlet water temperature sensor 414I, and the outlet water temperature sensor 4140) provided in the hot water supply unit 410 are read (S92i).
- the refrigerant pipe temperature is less than the water circuit freezing temperature TCOLD
- an instruction is issued to the branch control processing device 220 of the branch unit 210, and opening/closing of the solenoid valve 213b is controlled so that the gas branch pipe 003b (the refrigerant-water heat exchanger 411) and the gas-liquid separator 211 communicate with each other (S14i).
- the pressure in the refrigerant-water heat exchanger 411 can be increased to an intermediate pressure.
- the refrigerant pipe temperature rises. This makes it possible to avoid breakage of the heat exchanger due to freezing of water in the refrigerant-water heat exchanger 411 of the hot water supply unit 410.
- the solenoid valve 213 of the branch unit 210 is controlled to open so that the gas-liquid separator 211 and the refrigerant-water heat exchanger 411 communicate with each other, thereby increasing the pressure, and hence the temperature, at the refrigerant-side in the refrigerant-water heat exchanger 411. Therefore, freezing of water in the refrigerant-water heat exchanger 411 can be prevented. As a result, breakage of the refrigerant-water heat exchanger 411 can be prevented.
- the temperature from at least one of the hot-water-supply-unit gas pipe temperature sensor 413G and the hot-water-supply-unit liquid pipe temperature sensor 413L is less than the water circuit freezing temperature TCOLD, this should not be construed restrictively. For example, it may be determined whether the temperature from at least one of the inlet water temperature sensor 4141 and the outlet water temperature sensor 4140 is less than the water circuit freezing temperature TCOLD.
- water is used as an object with which refrigerant exchanges heat in the refrigerant-water heat exchanger 411
- an anti-freeze (brine) may be added.
- the kind of the anti-freeze used is not particularly limited but a suitable one, such as ethylene glycol or propylene glycol, may be selected in accordance with the availability and intended use.
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Abstract
Description
- The present invention relates to a combined air-conditioning and hot water supply system capable of performing air-conditioning and hot water supply by using a heat pump cycle.
- Combined air-conditioning and hot water supply systems have been proposed which use a heat pump cycle (refrigeration cycle) to exchange heat with a heat source such as air or water, and supply the heat to a plurality of indoor devices (indoor units) and a plurality of hot water supply devices (hot water supply units) (see, for example, Patent Literature 1). In these systems, a branch unit is connected to a heat source unit. At least one indoor unit and at least one hot water supply unit are connected to the branch unit. Consequently, air-conditioning and hot water supply can be executed simultaneously by use of a single heat source.
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- In the combined air-conditioning and hot water supply system described in
Patent Literature 1 mentioned above, for example, in a case where at least one indoor unit is executing heating and at least one hot water supply unit is being stopped during a time of high heating load, an expansion device in the hot water supply unit that is being stopped is closed to prevent passage of refrigerant through the expansion device. - At this time, for example, if a valve that constitutes the expansion device does not close properly, this can cause refrigerant to flow through a refrigerant-water heat exchanger in the hot water supply unit. At this time, if the temperature of refrigerant passing through the inside of the refrigerant-water heat exchanger is lower than or equal to the freezing temperature of water, this can cause water to freeze and expand in the refrigerant-water heat exchanger, leading to breakage of the refrigerant-water heat exchanger.
- The present invention has been made to address the above-mentioned problem, and accordingly it is an object of the present invention to provide a combined air-conditioning and hot water supply system that makes it possible to prevent freezing in the refrigerant-water heat exchanger in the hot water supply unit.
- A combined air-conditioning and hot water supply system according to the present invention includes a refrigerant circuit and a control processing device. The refrigerant circuit is formed by connecting, by pipes, at least one heat source unit including a compressor and a heat source-side heat exchanger, at least one indoor unit including an indoor-side heat exchanger and an indoor-side expansion device, at least one hot water supply unit including a refrigerant-water heat exchanger and a hot water supply-side expansion device, and a branch unit including a gas-liquid separator and a refrigerant flow control device. The gas-liquid separator supplies a gaseous refrigerant to the indoor unit and/or the hot water supply unit which heats a target with which the gaseous refrigerant exchanges heat, and supplies a liquid refrigerant to the indoor unit and/or the hot water supply unit which cools a target with which the liquid refrigerant exchanges heat. The refrigerant flow control device controls passage of a refrigerant to the indoor unit and the hot water supply unit. The control processing device performs a control that, while the hot water supply unit is stopped, increases a pressure in a refrigerant-side flow path in the refrigerant-water heat exchanger, if the control processing device determines that there is a possibility of freezing of water in a water-side flow path in the refrigerant-water heat exchanger. Advantageous Effects of Invention
- In the combined air-conditioning and hot water supply system according to the present invention, if the control processing device determines that there is a possibility of freezing of water in the water-side flow path in the refrigerant-water heat exchanger, the control processing device increases the pressure in the refrigerant-side flow path in the refrigerant-water heat exchanger, thereby preventing freezing of water in the refrigerant-water heat exchanger.
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- [
Fig. 1] Fig. 1 illustrates an example of the configuration of a combined air-conditioning and hotwater supply system 000 according toEmbodiment 1 of the present invention. - [
Fig. 2] Fig. 2 illustrates the flow of refrigerant in a cooling operation mode. - [
Fig. 3] Fig. 3 illustrates the flow of refrigerant in a heating operation mode. - [
Fig. 4] Fig. 4 illustrates the flow of refrigerant in a cooling main operation mode. - [
Fig. 5] Fig. 5 illustrates the flow of refrigerant in a heating main operation mode. - [
Fig. 6] Fig. 6 illustrates the procedure of a freezing prevention process according toEmbodiment 1 of the present invention. - [
Fig. 7] Fig. 7 illustrates the procedure of a freezing prevention process according toEmbodiment 2 of the present invention. - [
Fig. 8] Fig. 8 illustrates the procedure of a freezing prevention process according toEmbodiment 3 of the present invention. - Hereinafter, embodiments of the present invention will be described with reference to the drawings. It is to be understood that the configuration or the like of a combined air-conditioning and hot water supply system described with reference to the embodiments below is illustrative only and not limiting. Devices, apparatuses, and the like designated by reference signs with suffixes will be hereinafter sometimes denoted without suffixes, provided that these devices, apparatuses, and the like do not need to be particularly distinguished or identified.
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Fig. 1 illustrates an example of the configuration of a combined air-conditioning and hotwater supply system 000 according toEmbodiment 1 of the present invention. The configuration or the like of the system will be described with reference toFig. 1 . The combined air-conditioning and hotwater supply system 000 according toEmbodiment 1, which is installed in, for example, buildings, apartments, or hotels, has a refrigerant circuit formed by connecting apparatuses by pipes, and is capable of supplying heat (heating energy/cooling energy) to an air conditioning load and a hot water supply load simultaneously by using a heat pump cycle (refrigeration cycle). - The combined air-conditioning and hot
water supply system 000 according to Embodiment 1 at least has at least one heat source unit (outdoor device) 110, at least one branch unit (relay device) 210, at least one indoor unit (indoor device) 310, and a hotwater supply unit 410. Of these units, theindoor unit 310 and the hotwater supply unit 410, which serve as load units, are connected to theheat source unit 110 in a parallel fashion via thebranch unit 210. By, for example, switching the flow of refrigerant in thebranch unit 210 installed between theheat source unit 110 and each of theindoor unit 310 and the hotwater supply unit 410, theindoor unit 310 and the hotwater supply unit 410 are allowed to exert the function of executing space cooling (to be also referred to simply as "cooling" hereinafter) or space heating (to be also referred to simply as "heating" hereinafter) and the function of supplying hot water or cold water, respectively. WhileFig. 1 illustrates a case in which a singleindoor unit 310 and a single hotwater supply unit 410 are connected to thebranch unit 210, this is not intended to limit the number of these units to be connected. - In the combined air-conditioning and hot
water supply system 000, theheat source unit 110 and thebranch unit 210 are connected to each other by a high pressuremain pipe 001 and a low pressuremain pipe 002 that are refrigerant pipes, thus allowing refrigerant to flow. Thebranch unit 210 and theindoor unit 310 are connected to each other bygas branch pipes branch unit 210 and the hotwater supply unit 410 are connected to each other byliquid branch pipes 004a and 004b that are refrigerant pipes. - Now, refrigerants used in the combined air-conditioning and hot
water supply system 000 will be described. Refrigerants that can be used in the refrigeration cycle of the combined air-conditioning and hotwater supply system 000 include, for example, zeotropic refrigerant mixtures, near-azeotropic refrigerant mixtures, and single-component refrigerants. Zeotropic refrigerant mixtures are available in various kinds such as R407C (R32/R125/R134a), which is a hydrofluorocarbon (HFC) refrigerant. Accordingly, a refrigerant suited for the intended use or purpose of the combined air-conditioning and hotwater supply system 000 may be used. - Zeotropic refrigerant mixtures are mixtures made up of refrigerants with different boiling points, and thus have a characteristic such that the composition ratios of liquid-phase and gas-phase refrigerants differ from each other. Further, near-azeotropic refrigerant mixtures include R410A (R32/R125) and R404A (R125/R143a/R134a) that are HFC refrigerants. In addition to characteristics similar to those of zeotropic refrigerant mixtures, near-azeotropic refrigerant mixtures have such a characteristic that their operating pressure is approximately 1.6 times that of R22. Further, single-component refrigerants include R22, which is a hydrochlorofluorocarbon (HCFC) refrigerant, and R134a, which is a HFC refrigerant. Single-component refrigerants are not mixtures, and thus have the characteristic of being easy to handle. Other than these, natural refrigerants such as carbon hydrate, propane, isobutene, and ammonia may also be used. In the above description, R22 denotes chlorodifluoromethane, R32 denotes difluoromethane, R125 denotes pentafluoromethane, R134a denotes 1,1,1,2-tetrafluoromethane, and R143a denotes 1,1,1-trifluoroethane.
- The
heat source unit 110 has the function of sending refrigerant to theindoor unit 310 and the hotwater supply unit 410 via thebranch unit 210 to supply heating energy or cooling energy to a load. Theheat source unit 110 according toEmbodiment 1 includes a compressor 111, aflow switching valve 112, a heat source-side heat exchanger 113, and an accumulator (liquid reservoir) 115, which are connected in series as illustrated inFig. 1 . - The compressor 111 compresses a sucked refrigerant and discharges the refrigerant in a high-temperature/high-pressure state. The type of the compressor is not particularly limited. For example, compressors of various types, such as reciprocating, rotary, scroll, and screw types may be used as the compressor 111. The compressor 111 preferably includes a type of compressor whose rotation speed can be variably controlled by an inverter.
- The heat source-side heat exchanger 113 functions as a radiator (condenser) or an evaporator. The heat source-side heat exchanger 113 exchanges heat between the refrigerant and air, with which the refrigerant is to exchange heat, thereby causing the refrigerant to condense and liquefy or evaporate and gasify. In the case of performing a cooling and heating mixed operation in which heating energy and cooling energy are supplied simultaneously, the heat source-side heat exchanger 113 is sometimes used as a radiator. At this time, the refrigerant in gaseous form (gaseous refrigerant) from the compressor 111 is only partially condensed, resulting in a refrigerant in a two-phase state that is made up of a gaseous refrigerant and a refrigerant in liquid form (liquid refrigerant). In
Embodiment 1, in the heat source-side heat exchanger 113, heat is exchanged between the air from an air-blowing device 114 and refrigerant. However, for example, heat may be exchanged between water or brine and refrigerant. The air-blowing device 114, which includes a fan or the like, supplies the heat source-side heat exchanger 113 with the air with which refrigerant is to exchange heat. Theaccumulator 115, which is arranged on the suction side of the compressor 111, is a container for storing excess refrigerant. - A group of check valves (to be referred to as "check valve group" hereinafter) 116 regulates the flow of refrigerant so that refrigerant flows through the high pressure
main pipe 001 so as to exit theheat source unit 110 and enter thebranch unit 210, and refrigerant flows through the low pressuremain pipe 002 so as to exit thebranch unit 210 and enter theheat source unit 110. - A discharge pressure sensor 117H detects the discharge pressure of refrigerant. A suction pressure sensor 117L detects the suction pressure of refrigerant. A
discharge temperature sensor 118H detects the discharge temperature of refrigerant. A suction temperature sensor 118L detects the suction temperature of refrigerant. A heat-source heatexchanger temperature sensor 119a detects the temperature of refrigerant that enters and exits the heat source-side heat exchanger 113. An outsideair temperature sensor 119b detects the temperature of the outside air introduced into theheat source unit 110. A heat-sourcecontrol processing device 120 controls various actuators on the basis of temperatures, pressures, and the like detected by these various sensors. - The
branch unit 210 regulates the flow of refrigerant between load units (theindoor unit 310 and the hot water supply unit 410), and theheat source unit 110. Further, thebranch unit 210 causes each of anindoor heat exchanger 311 of theindoor unit 310, and a refrigerant-water heat exchanger 411 of the hotwater supply unit 410 to function as a radiator or an evaporator. Thebranch unit 210 at least has a gas-liquid separator 211, asolenoid valve 213a, asolenoid valve 213b, a liquidrefrigerant expansion device 212, abypass expansion device 214, and abranch pressure sensor 215 that is used to detect an intermediate pressure. - The
solenoid valve 213a, which serves as a refrigerant flow control device, connects to each of the low pressuremain pipe 002, thegas branch pipe 003a, and the gas-liquid separator 211. Thesolenoid valve 213a switches the flow path of refrigerant entering and exiting theindoor unit 310 on the basis of an instruction from a branchcontrol processing device 220, thereby controlling passage of refrigerant. Further, thesolenoid valve 213b, which serves as a hot-water-supply-unit flow switching device, connects to each of the low pressuremain pipe 002, thegas branch pipe 003a, and the gas-liquid separator 211. Thesolenoid valve 213b switches the flow path of refrigerant entering and exiting the hotwater supply unit 410 on the basis of an instruction from the branchcontrol processing device 220, thereby controlling passage of refrigerant. The number of solenoid valves 213 is not particularly limited but may be determined as required. While the solenoid valve 213 includes a combination of two two-way solenoid valves inFig. 1 , the solenoid valve 213 may be include a combination of three-way valves or the like. - The gas-
liquid separator 211 separates the refrigerant that has entered the gas-liquid separator 211 from the high pressuremain pipe 001 into a gaseous refrigerant and a liquid refrigerant. The gaseous refrigerant flows toward the solenoid valve 213 (213a and 213b). The liquid refrigerant separated by the gas-liquid separator 211 flows toward the liquidrefrigerant expansion device 212. The liquidrefrigerant expansion device 212 reduces the pressure of the liquid refrigerant flowing from the gas-liquid separator 211, causing the liquid refrigerant to expand. Thebypass expansion device 214 regulates, for example, the pressure and amount of refrigerant that exits each of theindoor unit 310 and the hotwater supply unit 410 and flows to the low pressuremain pipe 002. Each of the liquidrefrigerant expansion device 212 and thebypass expansion device 214 preferably includes, for example, flow control means based on an electronic expansion valve whose opening degree can be varied by fine control, or inexpensive refrigerant flow control means such as a capillary. - The
branch pressure sensor 215 is a sensor that detects intermediate pressure. In this regard, thebranch unit 210 has the following three pressure ranges: the pressure of refrigerant that enters thebranch unit 210 from the heat source unit 110 (high pressure); the pressure of refrigerant that enters the heat source unit 110 (low pressure); and the intermediate pressure between the high pressure and the low pressure. The intermediate pressure can be changed by changing the opening degrees of the liquidrefrigerant expansion device 212 and thebypass expansion device 214. A change in intermediate pressure changes the ratio between the flow of refrigerant passed to the space heating (hot water supply) side and the flow of refrigerant passed to the space cooling (cooling) side, causing the ratio between space heating (hot water supply) and space cooling (cooling) capacities to change. The branchcontrol processing device 220 controls the opening degrees of the liquidrefrigerant expansion device 212 and thebypass expansion device 214 on the basis of the pressure detected by thebranch pressure sensor 215. - The
indoor unit 310 has the function of drawing heating energy or cooling energy from the refrigerant delivered from theheat source unit 110, and supplying the heating energy or the cooling energy to the air conditioning load. Theindoor unit 310 according toEmbodiment 1 includes an indoor-unit expansion device 312 and theindoor heat exchanger 311, which are connected in series as illustrated inFig. 1 . Although not particularly illustrated inFig. 1 , in theindoor unit 310, an air-blowing device such as a fan for supplying air to theindoor heat exchanger 311 may be provided near theindoor heat exchanger 311. - The
indoor heat exchanger 311 functions as a radiator (condenser) in the heating operation, and functions as an evaporator in the cooling operation. Theindoor heat exchanger 311 exchanges heat between the refrigerant and the air in an air-conditioned space, thereby causing the refrigerant to condense and liquefy or evaporate and gasify. The indoor-unit expansion device 312, which includes, for example, a pressure reducing valve (expansion valve), causes refrigerant to expand by reducing its pressure. The pressure reducing valve preferably includes, for example, flow control means based on an electronic expansion valve whose opening degree can be varied by fine control, or inexpensive refrigerant flow control means such as a capillary. - An indoor-unit gas
pipe temperature sensor 313G and an indoor-unit liquidpipe temperature sensor 313L are installed at positions in the pipe where refrigerant enters and exits theindoor heat exchanger 311, respectively. An indoor air temperature sensor 314 detects the temperature of at least one of the air sucked into theindoor heat exchanger 311 and the air expelled from theindoor heat exchanger 311. On the basis of temperatures detected by these temperature sensors, an indoorcontrol processing device 320 controls the opening degree of the indoor-unit expansion device 312 to control the flow rate of refrigerant. - The hot
water supply unit 410 has the function of drawing heating energy or cooling energy from the refrigerant delivered from theheat source unit 110, and supplying the heating energy or the cooling energy to the hot water supply load. The hotwater supply unit 410 according toEmbodiment 1 includes a hot-water-supply-unit expansion device 412 and the refrigerant-water heat exchanger 411, which are connected in series as illustrated inFig. 1 . - The refrigerant-
water heat exchanger 411 functions as a radiator (condenser) or an evaporator. The refrigerant-water heat exchanger 411 exchanges heat between the refrigerant and the water that passes through awater pipe 010, thereby causing the refrigerant to condense and liquefy or evaporate and gasify. The hot-water-supply-unit expansion device 412, which includes, for example, a pressure reducing valve (expansion valve), causes refrigerant to expand by reducing its pressure. Like the indoor-unit expansion device 312, the hot-water-supply-unit expansion device 412 preferably includes, for example, flow control means or refrigerant flow control means. - A hot-water-supply-unit gas
pipe temperature sensor 413G and a hot-water-supply-unit liquidpipe temperature sensor 413L are installed at positions in the pipe where refrigerant enters and exits the refrigerant-water heat exchanger 411, respectively. Further, an inlet water temperature sensor 4141 and an outletwater temperature sensor 4140 are installed at positions in the pipe where water enters and exits the refrigerant-water heat exchanger 411. On the basis of temperatures detected by these temperature sensors, a hot-water-supplycontrol processing device 420 controls the opening degree of the hot-water-supply-unit expansion device 412 to control the flow rate of refrigerant. Further, it is preferable to provide, for example, a sensor that detects the temperature of water stored in a hot water storage tank (not illustrated). - The
water pipe 010 is a pipe that forms a water circuit by connecting a pump (not illustrated), the hot water storage tank, the refrigerant-water heat exchanger 411, and the like. In the water circuit, water that has been heated or cooled through heat exchange in the refrigerant-water heat exchanger 411 circulates. Thewater pipe 010 preferably includes a copper pipe, a stainless pipe, a steel pipe, a vinyl chloride pipe, or the like. While water is circulated in the water circuit inEmbodiment 1, for example, an antifreeze may be circulated in the water circuit. - The
heat source unit 110, thebranch unit 210, theindoor unit 310, and the hotwater supply unit 410 have the heat-sourcecontrol processing device 120, the branchcontrol processing device 220, the indoorcontrol processing device 320, and the hot-water-supplycontrol processing device 420, respectively. Although each of the control processing devices is provided in the corresponding one of these units, these control processing devices may be integrated into a single or a plurality of control processing devices. - The heat-source
control processing device 120 provided in theheat source unit 110 controls the pressure and temperature states of refrigerant in the combined air-conditioning and hotwater supply system 000, for example. Specifically, for example, the heat-sourcecontrol processing device 120 executes processing such as control of the driving frequency of the compressor 111, control of the fan rotation speed of the air-blowing device 114, and switching of theflow switching valve 112. - The branch
control processing device 220 provided in thebranch unit 210 executes processing such as control of the opening degrees of the liquidrefrigerant expansion device 212 and thebypass expansion device 214, and opening and closing control of the solenoid valve 213 (thesolenoid valve 213a and thesolenoid valve 213b). - The indoor
control processing device 320 provided in theindoor unit 310 controls various apparatuses to provide air conditioning for an air-conditioned space. For example, the indoorcontrol processing device 320 controls the degree of superheat of refrigerant when cooling is performed in theindoor unit 310, and controls the degree of subcooling of refrigerant when heating is performed in theindoor unit 310. Specifically, the indoorcontrol processing device 320 executes processing such as control of the fan rotation speed of an air-blowing device (not illustrated), and control of the opening degree of the indoor-unit expansion device 312. - The hot-water-supply
control processing device 420 of the hotwater supply unit 410 has the function of controlling the degree of superheat when cooling is executed by the hotwater supply unit 410, and the degree of subcooling when heating (hot water supply) is executed by the hotwater supply unit 410, on the basis of, for example, temperatures obtained from the hot-water-supply-unit gaspipe temperature sensor 413G and the hot-water-supply-unit liquidpipe temperature sensor 413L. Specifically, the hot-water-supplycontrol processing device 420 has the function of varying the area of heat exchange in the refrigerant-water heat exchanger 411, or controlling the opening degree of the hot-water-supply-unit expansion device 412. Further, in this example, the hot-water-supplycontrol processing device 420 executes a process that prevents freezing of the water-side flow path in the refrigerant-water heat exchanger 411 while the hotwater supply unit 410 is stopped. It is assumed that the hot-water-supplycontrol processing device 420 has clock means (timer) to execute this process. - Next, the operational behavior of the combined air-conditioning and hot
water supply system 000 will be described. There are four operation modes that can be executed by the combined air-conditioning and hotwater supply system 000 according toEmbodiment 1. First, there is a cooling operation mode in which all of theindoor units 310 that are running execute space cooling, and the hotwater supply unit 410 executes cooling. There is also a heating operation mode in which all of theindoor units 310 that are running execute space heating, and the hotwater supply unit 410 executes hot water supply (heating). - Further, there is a cooling main operation mode in which, when the
indoor unit 310 that is executing space heating and theindoor unit 310 that is executing space cooling are mixed, and cooling or hot water supply is executed in the hotwater supply unit 410, the space cooling/cooling load is greater. Furthermore, there is a heating main operation mode in which, when theindoor unit 310 that is executing space heating and theindoor unit 310 that is executing space cooling are mixed, and cooling or hot water supply is executed in the hotwater supply unit 410, the space heating/hot water supply load is greater. The cooling main operation mode and the heating main operation mode are switched so as to maximize capacity or efficiency by, for example, comparing the condensing temperature and evaporating temperature of refrigerant in the combined air-conditioning and hotwater supply system 000 with target values set within theheat source unit 110. -
Fig. 2 illustrates the flow of refrigerant in the cooling operation mode. First, a description will be given of the flow of refrigerant and the details of operation in the cooling operation mode when all of theindoor units 310 that are running are in space cooling operation, and the hotwater supply unit 410 is in the cooling operation. - In the
heat source unit 110, a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then enters the heat source-side heat exchanger 113 via theflow switching valve 112. The high-pressure gaseous refrigerant that has entered the heat source-side heat exchanger 113 condenses into a high-pressure liquid refrigerant by exchanging heat with the air supplied to the heat source-side heat exchanger 113, and then exits the heat source-side heat exchanger 113. The high-pressure liquid refrigerant that has exited the heat source-side heat exchanger 113 exits theheat source unit 110 via thecheck valve group 116. Then, the high-pressure liquid refrigerant flows through the high pressuremain pipe 001, and enters thebranch unit 210. - In the
branch unit 210, the high-pressure liquid refrigerant that has entered thebranch unit 210 from the high pressuremain pipe 001 passes through the gas-liquid separator 211 and the liquidrefrigerant expansion device 212, and exits thebranch unit 210. The refrigerant that has exited thebranch unit 210 flows through theliquid branch pipe 004, and enters theindoor unit 310 and the hotwater supply unit 410. In theindoor unit 310, the refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the indoor-unit expansion device 312, and flows to theindoor heat exchanger 311. The low-pressure two-phase refrigerant or the low-pressure liquid refrigerant that has entered theindoor heat exchanger 311 evaporates in theindoor heat exchanger 311 into a low-pressure gaseous refrigerant, and exits theindoor heat exchanger 311. - In the hot
water supply unit 410, the refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the hot-water-supply-unit expansion device 412, and flows to the refrigerant-water heat exchanger 411. The low-pressure two-phase refrigerant or the low-pressure liquid refrigerant that has entered the refrigerant-water heat exchanger 411 evaporates in the refrigerant-water heat exchanger 411 into a low-pressure gaseous refrigerant, and exits the refrigerant-water heat exchanger 411. - The flows of low-pressure gaseous refrigerant that have exited the
indoor heat exchanger 311 and the refrigerant-water heat exchanger 411 exit theindoor unit 310 and the hotwater supply unit 410, respectively. Then, each of the flows of refrigerant flows through the gas branch pipe 003, and enters thebranch unit 210. The low-pressure gaseous refrigerant that has entered thebranch unit 210 flows to the low pressuremain pipe 002 via the solenoid valve 213. The low-pressure gaseous refrigerant that has flown to the low pressuremain pipe 002 exits thebranch unit 210, and then enters theheat source unit 110. The low-pressure gaseous refrigerant that has entered theheat source unit 110 is sucked into the compressor 111 again via thecheck valve group 116, theflow switching valve 112, and theaccumulator 115. -
Fig. 3 illustrates the flow of refrigerant in the heating operation mode. First, a description will be given of the flow of refrigerant and the details of operation in the heating operation mode when all of theindoor units 310 that are running are in space heating operation, and the hotwater supply unit 410 is in the hot water supply operation. - In the
heat source unit 110, a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then exits theheat source unit 110 via theflow switching valve 112 and thecheck valve group 116. Then, after passing through the high pressuremain pipe 001, the high temperature/high pressure gaseous refrigerant enters thebranch unit 210. In thebranch unit 210, the high-pressure gaseous refrigerant that has entered thebranch unit 210 from the high pressuremain pipe 001 passes through the gas-liquid separator 211 and the solenoid valve 213, and exits thebranch unit 210. Then, the high-pressure gaseous refrigerant flows through the gas branch pipe 003, and enters theindoor unit 310 and the hotwater supply unit 410. - The high-pressure gaseous refrigerant that has entered the
indoor unit 310 enters theindoor heat exchanger 311, and is condensed in theindoor heat exchanger 311. Further, in the indoor-unit expansion device 312, the resulting refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure, and exits theindoor unit 310. Then, the resulting refrigerant flows through the liquid branch pipe 004a, and enters thebranch unit 210. - The high-pressure gaseous refrigerant that has entered the hot
water supply unit 410 enters the refrigerant-water heat exchanger 411. In the refrigerant-water heat exchanger 411, the high-pressure gaseous refrigerant is condensed into a high-pressure liquid refrigerant, and then exits the refrigerant-water heat exchanger 411. The high-pressure liquid refrigerant that has exited the refrigerant-water heat exchanger 411 turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the hot-water-supply-unit expansion device 412, and exits the hotwater supply unit 410. Then, the resulting refrigerant flows through theliquid branch pipe 004b, and enters thebranch unit 210. - These flows of low-pressure refrigerant that have entered the
branch unit 210 are merged, and the resulting refrigerant flows to the low pressuremain pipe 002 via thebypass expansion device 214. The low-pressure refrigerant that flows from the low pressuremain pipe 002 exits thebranch unit 210, and then enters theheat source unit 110. The refrigerant that has entered theheat source unit 110 is sucked into the compressor 111 again via thecheck valve group 116, the heat source-side heat exchanger 113, theflow switching valve 112, and theaccumulator 115. -
Fig. 4 illustrates the flow of refrigerant in the cooling main operation mode. Hereinafter, a description will be given of the flow of refrigerant and the details of operation in the cooling main operation mode in which, for example, theindoor unit 310 is executing space cooling and the hotwater supply unit 410 is executing hot water supply, and the space cooling load is greater than the space heating load. - In the
heat source unit 110, a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then enters the heat source-side heat exchanger 113 via theflow switching valve 112. The high-pressure gaseous refrigerant that has entered the heat source-side heat exchanger 113 condenses into a two-phase liquid-gas refrigerant at high pressure by exchanging heat with the air supplied to the heat source-side heat exchanger 113, and then exits the heat source-side heat exchanger 113. The high-pressure two-phase refrigerant that has exited the heat source-side heat exchanger 113 exits theheat source unit 110 via thecheck valve group 116. Then, the high-pressure two-phase refrigerant flows through the high pressuremain pipe 001, and enters thebranch unit 210. - In the
branch unit 210, the high-pressure two-phase refrigerant that has entered thebranch unit 210 from the high pressuremain pipe 001 is separated in the gas-liquid separator 211 into high-pressure saturated gas and high-pressure saturated liquid. The high-pressure saturated gas separated by the gas-liquid separator 211 exits thebranch unit 210 via thesolenoid valve 213b, and passes through thegas branch pipe 003b to enter the hotwater supply unit 410. The refrigerant that has entered the hotwater supply unit 410 is condensed in the refrigerant-water heat exchanger 411 into a high-pressure liquid refrigerant, and then exits the refrigerant-water heat exchanger 411. The high-pressure liquid refrigerant that has exited the refrigerant-water heat exchanger 411 turns into a two-phase liquid-gas refrigerant at intermediate pressure or a liquid refrigerant at intermediate pressure in the hot-water-supply-unit expansion device 412, and exits the hotwater supply unit 410. Then, the resulting refrigerant flows through theliquid branch pipe 004b, and enters thebranch unit 210. The refrigerant that has entered thebranch unit 210 is re-used when cooling is performed by theindoor unit 310. - Meanwhile, the high-pressure saturated liquid separated by the gas-
liquid separator 211 passes through the liquidrefrigerant expansion device 212, and merges with the refrigerant that has flown from the hotwater supply unit 410. Then, after exiting thebranch unit 210, the resulting refrigerant flows through the liquid branch pipe 004a, and enters theindoor unit 310. In theindoor unit 310, the refrigerant turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the indoor-unit expansion device 312, and flows to theindoor heat exchanger 311. The low-pressure two-phase refrigerant or the low-pressure liquid refrigerant that has entered theindoor heat exchanger 311 evaporates in theindoor heat exchanger 311 into a low-pressure gaseous refrigerant, and exits theindoor heat exchanger 311. The low-pressure gaseous refrigerant that has exited theindoor heat exchanger 311 flows through thegas branch pipe 003a, and enters thebranch unit 210. - At this time, as the amount of liquid refrigerant that accumulates in the section of the
liquid branch pipe 004 increases, the pressure in the liquid pipe rises. If, for example, there is anyindoor unit 310 that is executing heating at this time, the pressure difference with respect to the liquid pipe decreases, which causes a decrease in the amount of refrigerant that flows to theindoor unit 310 that is executing heating, leading to a decrease in heating capacity. Accordingly, to release liquid accumulating in the liquid line, thebypass expansion device 214 is opened to an appropriate degree, thus allowing the liquid accumulating in the liquid line to pass to the low pressuremain pipe 002 to regulate the pressure in the liquid line. At this time, for example, the refrigerant that has exited thebranch unit 210 turns into a low-pressure two-phase refrigerant as the low-pressure gaseous refrigerant that has entered from theindoor unit 310 and the liquid refrigerant that has entered from thebypass expansion device 214 are mixed. The low-pressure two-phase refrigerant that has entered thebranch unit 210 passes through thesolenoid valve 213a, and exits thebranch unit 210. Then, the low-pressure two-phase refrigerant flows through the low pressuremain pipe 002, and enters theheat source unit 110. The low-pressure two-phase refrigerant that has entered theheat source unit 110 is sucked into the compressor 111 again via thecheck valve group 116, theflow switching valve 112, and theaccumulator 115. -
Fig. 5 illustrates the flow of refrigerant in the heating main operation mode. Hereinafter, a description will be given of the flow of refrigerant and the details of operation in the heating main operation mode in which, for example, theindoor unit 310 is executing space heating and the hotwater supply unit 410 is executing cooling, and the space heating load is greater than the space cooling load. - In the
heat source unit 110, a low-pressure gaseous refrigerant is sucked into the compressor 111, where the refrigerant turns into a high temperature/high pressure gaseous refrigerant, which then exits theheat source unit 110 via theflow switching valve 112 and thecheck valve group 116. Then, the high temperature/high pressure gaseous refrigerant passes through the high pressuremain pipe 001, and enters thebranch unit 210. In thebranch unit 210, the high-pressure gaseous refrigerant that has entered thebranch unit 210 from the high pressuremain pipe 001 passes through the gas-liquid separator 211 and thesolenoid valve 213a, and exits thebranch unit 210. Then, the high-pressure gaseous refrigerant flows through thegas branch pipe 003a, and enters theindoor unit 310. - The high-pressure gaseous refrigerant that has entered the
indoor unit 310 enters theindoor heat exchanger 311, and is condensed in theindoor heat exchanger 311. Further, in the indoor-unit expansion device 312, the refrigerant turns into a two-phase liquid-gas refrigerant at intermediate pressure, or a liquid refrigerant at intermediate pressure, and exits theindoor unit 310. Then, the resulting refrigerant flows through the liquid branch pipe 004a, and enters thebranch unit 210. - The intermediate-pressure refrigerant that has entered the
branch unit 210 exits thebranch unit 210, and flows through theliquid branch pipe 004b to enter the hotwater supply unit 410. The refrigerant that has entered the hotwater supply unit 410 turns into a two-phase liquid-gas refrigerant at low pressure, or a liquid refrigerant at low pressure in the hot-water-supply-unit expansion device 412, and enters the refrigerant-water heat exchanger 411. The low-pressure liquid refrigerant that has entered the refrigerant-water heat exchanger 411 evaporates into a low-pressure gaseous refrigerant, and exits the hotwater supply unit 410. Then, the low-pressure gaseous refrigerant flows through theliquid branch pipe 004b, and enters thebranch unit 210. - At this time, as in the case of the cooling main operation mode, as the amount of liquid refrigerant that accumulates in the section of the
liquid branch pipe 004 increases, the pressure in the liquid pipe rises. As a result, the amount of refrigerant that flows to theindoor unit 310 that is executing heating decreases, leading to a decrease in heating capacity. Accordingly, thebypass expansion device 214 is opened to an appropriate degree to regulate the pressure in the liquid line. At this time, for example, the low-pressure gaseous refrigerant that has entered from the hotwater supply unit 410 and the liquid refrigerant that has entered from thebypass expansion device 214 are mixed, resulting in a low-pressure two-phase refrigerant. The low-pressure two-phase refrigerant passes through thesolenoid valve 213a, and exits thebranch unit 210. Then, the low-pressure two-phase refrigerant flows through the low pressuremain pipe 002, and enters theheat source unit 110. The low-pressure two-phase refrigerant that has entered theheat source unit 110 is sucked into the compressor 111 again via thecheck valve group 116, theflow switching valve 112, and theaccumulator 115. -
Fig. 6 illustrates the procedure of a freezing prevention process according toEmbodiment 1 of the present invention. Referring toFig. 6 , a freezing prevention process for a water circuit (the refrigerant-water heat exchanger 411) according toEmbodiment 1 will be described. This process is executed while, for example, heating or cooling of water is stopped in the hotwater supply unit 410. - The hot-water-supply
control processing device 420 starts a control according to the freezing prevention process (S01i). At this time, thesolenoid valve 213b is in a closed state, and the opening degree of the hot-water-supply-unit expansion device 412 is basically zero. - Then, temperatures detected by various temperature sensors (the hot-water-supply-unit gas
pipe temperature sensor 413G, the hot-water-supply-unit liquidpipe temperature sensor 413L, the inlet water temperature sensor 414I, and the outlet water temperature sensor 4140) provided in the hotwater supply unit 410 are read (S02i). - It is determined whether the refrigerant pipe temperature detected by at least one of the hot-water-supply-unit gas
pipe temperature sensor 413G and the hot-water-supply-unit liquidpipe temperature sensor 413L is less than a water circuit freezing temperature TCOLD (refrigerant pipe temperature < TCOLD) (S03i). For this determination, it may be determined whether one of the refrigerant pipe temperatures detected by the hot-water-supply-unit gaspipe temperature sensor 413G and the hot-water-supply-unit liquidpipe temperature sensor 413L is less than the water circuit freezing temperature TCOLD, or it may be determined whether both of the refrigerant pipe temperatures are less than the water circuit freezing temperature TCOLD. If it is determined in S03i that the refrigerant pipe temperature is not less than the water circuit freezing temperature TCOLD (the refrigerant pipe temperature is higher than or equal to the water circuit freezing temperature TCOLD), the process is ended (S08i). - There are times when, for example, the pressure of liquid refrigerant is high while cooling is performed in the
indoor unit 310. If the hot-water-supply-unit expansion device 412 is not completely closed in this case, the refrigerant whose pressure has been reduced in the hot-water-supply-unit expansion device 412 flows into the refrigerant-water heat exchanger 411. Consequently, the water in the refrigerant-water heat exchanger 411 is cooled by this refrigerant. Accordingly, if it is determined in S03i that the refrigerant pipe temperature is less than the water circuit freezing temperature TCOLD, the opening degree of the hot-water-supply-unit expansion device 412 is increased (opened) to any given opening degree A (A>0) (S04i). Increasing the opening degree makes it possible to reduce pressure loss in the pipe between thebranch unit 210 and the hotwater supply unit 410. As a result, the pressure of refrigerant in the refrigerant-water heat exchanger 411 rises from a low pressure to an intermediate pressure. This rise in pressure causes a rise in refrigerant pipe temperature, making it possible to avoid breakage of the heat exchanger due to freezing of the water circuit portion of the refrigerant-water heat exchanger 411 in the hotwater supply unit 410. - At this time, opening the hot-water-supply-
unit expansion device 412 to any given opening degree does not cause an instantaneous rise in refrigerant pipe temperature. Accordingly, it is determined whether any given set time or more has elapsed since the hot-water-supply-unit expansion device 412 is opened (S05i). The opening degree is maintained in the current state until it is determined that the elapsed time has reached the set time or more (S07i). If it is determined that the set time has elapsed, the opening degree of the hot-water-supply-unit expansion device 412 is reset to the original state (S06i), and the process is ended (S08i). The above process is executed while heating or cooling of water is stopped in the hotwater supply unit 410. - As described above, in the combined air-conditioning and hot water supply system according to
Embodiment 1, while the hotwater supply unit 410 is stopped, if, for example, the refrigerant leakage or the like due to incomplete closure of the opening degree of the hot-water-supply-unit expansion device 412 causes the refrigerant temperature in the refrigerant-water heat exchanger 411 to decrease, and it is determined as a result that the refrigerant pipe temperature is less than the water circuit freezing temperature TCOLD, the hot-water-supply-unit expansion device 412 is opened to the opening degree A to increase the pressure, and hence the temperature, at the refrigerant side in the refrigerant-water heat exchanger 411. Therefore, freezing of water in the refrigerant-water heat exchanger 411 can be prevented. As a result, breakage of the refrigerant-water heat exchanger 411 can be prevented. -
Fig. 7 illustrates the procedure of a freezing prevention process according toEmbodiment 2 of the present invention. In the process for preventing freezing of water in the refrigerant-water heat exchanger 411 according toEmbodiment 1 mentioned above, for example, inFig. 6 , the hot-water-supply-unit expansion device 412 is closed upon elapse of a set time on the basis of S05i, S06i, and S07i. - However, closing the hot-water-supply-
unit expansion device 412 that is open can lead to loss of stability of the refrigeration cycle in the refrigerant circuit. Further, closing the hot-water-supply-unit expansion device 412 creates a liquid seal of refrigerant in the refrigerant-water heat exchanger 411, which may lead to breakage of the hot water supply unit 410 (the refrigerant-water heat exchanger 411). Accordingly, inEmbodiment 2, once the hot-water-supply-unit expansion device 412 is opened to any given opening degree, S06i, S07i, and S08i are not performed, and the hot-water-supply-unit expansion device 412 is not closed while heating or cooling of water is stopped in the hotwater supply unit 410. -
Fig. 8 illustrates the procedure of a freezing prevention process according toEmbodiment 3 of the present invention. InEmbodiments water heat exchanger 411 decreases, the opening degree of the hot-water-supply-unit expansion device 412 is regulated to prevent freezing. InEmbodiment 3, freezing is prevented by switching thesolenoid valve 213b. - The hot-water-supply
control processing device 420 starts a control according to the freezing prevention process (S11i). At this time, thesolenoid valve 213b is in a closed state, and the opening degree of the hot-water-supply-unit expansion device 412 is basically zero. - Then, temperatures detected by various temperature sensors (the hot-water-supply-unit gas
pipe temperature sensor 413G, the hot-water-supply-unit liquidpipe temperature sensor 413L, the inlet water temperature sensor 414I, and the outlet water temperature sensor 4140) provided in the hotwater supply unit 410 are read (S92i). - It is determined whether the refrigerant pipe temperature detected by each of the hot-water-supply-unit gas
pipe temperature sensor 413G and the hot-water-supply-unit liquidpipe temperature sensor 413L is less than the water circuit freezing temperature TCOLD (S13i). For this determination, as in S03i described above with reference toEmbodiment 1, it may be determined whether one of the refrigerant pipe temperatures detected by the hot-water-supply-unit gaspipe temperature sensor 413G and the hot-water-supply-unit liquidpipe temperature sensor 413L is less than the water circuit freezing temperature TCOLD, or it may be determined whether both of the refrigerant pipe temperatures are less than the water circuit freezing temperature TCOLD. If it is determined in S13i that each refrigerant pipe temperature is not less than the water circuit freezing temperature TCOLD (the refrigerant pipe temperature is higher than or equal to the water circuit freezing temperature TCOLD), the process is ended (S18i). - If it is determined that the refrigerant pipe temperature is less than the water circuit freezing temperature TCOLD, an instruction is issued to the branch
control processing device 220 of thebranch unit 210, and opening/closing of thesolenoid valve 213b is controlled so that thegas branch pipe 003b (the refrigerant-water heat exchanger 411) and the gas-liquid separator 211 communicate with each other (S14i). For example, when the gas-liquid separator 211, thesolenoid valve 213b, thegas branch pipe 003b, and the hot water supply unit 410 (the refrigerant-water heat exchanger 411) communicate with each other, the pressure in the refrigerant-water heat exchanger 411 can be increased to an intermediate pressure. As the pressure in the refrigerant-water heat exchanger 411 rises from a low pressure to an intermediate pressure, the refrigerant pipe temperature rises. This makes it possible to avoid breakage of the heat exchanger due to freezing of water in the refrigerant-water heat exchanger 411 of the hotwater supply unit 410. - At this time, even when communication is established between the
gas branch pipe 003b and the gas-liquid separator 211, this does not cause an instantaneous rise in refrigerant pipe temperature. Accordingly, it is determined whether any given set time or more has elapsed since thesolenoid valve 213b is controlled (S15i). Thesolenoid valve 213b is maintained in the current state until it is determined that the elapsed time has reached the set time or more (S17i). If it is determined that the set time has elapsed, thesolenoid valve 213b is closed (S16i), and the process is ended (S18i). The above process is executed while heating or cooling of water is stopped in the hotwater supply unit 410. At this time, depending on the case, S15i to S17i may not be executed as inEmbodiment 2 mentioned above. - As described above, in the combined air-conditioning and hot water supply system according to
Embodiment 3, for example, while the hotwater supply unit 410 is stopped, if it is determined that the refrigerant pipe temperature is less than the water circuit freezing temperature TCOLD, the solenoid valve 213 of thebranch unit 210 is controlled to open so that the gas-liquid separator 211 and the refrigerant-water heat exchanger 411 communicate with each other, thereby increasing the pressure, and hence the temperature, at the refrigerant-side in the refrigerant-water heat exchanger 411. Therefore, freezing of water in the refrigerant-water heat exchanger 411 can be prevented. As a result, breakage of the refrigerant-water heat exchanger 411 can be prevented. - In the embodiments mentioned above, it is determined whether the temperature from at least one of the hot-water-supply-unit gas
pipe temperature sensor 413G and the hot-water-supply-unit liquidpipe temperature sensor 413L is less than the water circuit freezing temperature TCOLD, this should not be construed restrictively. For example, it may be determined whether the temperature from at least one of the inlet water temperature sensor 4141 and the outletwater temperature sensor 4140 is less than the water circuit freezing temperature TCOLD. - In the embodiments mentioned above, to execute hot water supply (water supply), water is used as an object with which refrigerant exchanges heat in the refrigerant-
water heat exchanger 411, this should not be construed restrictively. For example, if there is a possibility that thewater pipe 010 may freeze under an environment in which the temperature of water in the refrigerant-water heat exchanger 411 drops to a low temperature, an anti-freeze (brine) may be added. The kind of the anti-freeze used is not particularly limited but a suitable one, such as ethylene glycol or propylene glycol, may be selected in accordance with the availability and intended use. - 000 combined air-conditioning and hot
water supply system 001 high pressuremain pipe 002 low pressuremain pipe gas branch pipe liquid branch pipe 010water pipe 110 heat source unit 111compressor 112 flow switching valve 113 heat source-side heat exchanger 114 air-blowingdevice 115accumulator 116 check valve group 117H discharge pressure sensor 117Lsuction pressure sensor 118H discharge temperature sensor 118Lsuction temperature sensor 119a heat-source heatexchanger temperature sensor 119b outsidetemperature sensor 120 heat-sourcecontrol processing device 210branch unit 211 gas-liquid separator 212 liquidrefrigerant expansion device 213b solenoid valve 214bypass expansion device 215branch pressure sensor 220 branchcontrol processing device 310indoor unit 311indoor heat exchanger 312 indoor-unit expansion device 313G indoor-unit gaspipe temperature sensor 313L indoor-unit liquid pipe temperature sensor 314 indoorair temperature sensor 320 indoorcontrol processing device 410 hotwater supply unit 411 refrigerant-water heat exchanger 412 hot-water-supply-unit expansion device 413G hot-water-supply-unit gaspipe temperature sensor 413L hot-water-supply-unit liquid pipe temperature sensor 414I inletwater temperature sensor 4140 outletwater temperature sensor 420 hot-water-supply control processing device
Claims (6)
- A combined air-conditioning and hot water supply system comprising:a refrigerant circuit formed by connecting, by pipes,at least one heat source unit including a compressor and a heat source-side heat exchanger,at least one indoor unit including an indoor-side heat exchanger and an indoor-side expansion device,at least one hot water supply unit including a refrigerant-water heat exchanger and a hot water supply-side expansion device, anda branch unit includinga gas-liquid separator that supplies a gaseous refrigerant to the indoor unit and/or the hot water supply unit heating a heat exchange target with which the gaseous refrigerant exchanges heat, and supplies a liquid refrigerant to the indoor unit and/or the hot water supply unit cooling a heat exchange target with which the liquid refrigerant exchanges heat, anda refrigerant flow control device that controls passage of a refrigerant to the indoor unit and the hot water supply unit; anda control processing device that, while the hot water supply unit is stopped, performs a control that increases a pressure in a refrigerant-side flow path in the refrigerant-water heat exchanger, if the control processing device determines that there is a possibility of freezing of water in a water-side flow path in the refrigerant-water heat exchanger.
- The combined air-conditioning and hot water supply system of claim 1, wherein if the control processing device determines that there is a possibility of freezing of water in the refrigerant-water heat exchanger, the control processing device opens the hot water supply-side expansion device to a predetermined opening degree.
- The combined air-conditioning and hot water supply system of claim 1, wherein if the control processing device determines that there is a possibility of freezing of water in the refrigerant-water heat exchanger, the control processing device causes the refrigerant flow control device to communicate the refrigerant-side flow path in the refrigerant-water heat exchanger with a gas supply side of the gas-liquid separator.
- The combined air-conditioning and hot water supply system of any one of claims 1 to 3, wherein if the control processing device determines that a predetermined time has elapsed after the control that increases the pressure is performed, the control processing device returns processing to a state prior to the control.
- The combined air-conditioning and hot water supply system of any one of claims 1 to 4, further comprising:refrigerant-side temperature detecting means that detects a temperature in the refrigerant-side flow path in the refrigerant-water heat exchanger,wherein the control processing device determines whether there is a possibility of freezing on a basis of the temperature detected by the refrigerant-side temperature detecting means.
- The combined air-conditioning and hot water supply system of any one of claims 1 to 4, further comprising:water-side temperature detecting means that detects a temperature in the water-side flow path in the refrigerant-water heat exchanger,wherein the control processing device determines whether there is a possibility of freezing on a basis of the temperature detected by the water-side temperature detecting means.
Applications Claiming Priority (1)
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PCT/JP2012/074450 WO2014049673A1 (en) | 2012-09-25 | 2012-09-25 | Combined air-conditioning and hot-water supply system |
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EP2902726A1 true EP2902726A1 (en) | 2015-08-05 |
EP2902726A4 EP2902726A4 (en) | 2016-06-08 |
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EP (1) | EP2902726B1 (en) |
JP (1) | JP5893151B2 (en) |
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Cited By (3)
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EP3205954A1 (en) * | 2016-02-12 | 2017-08-16 | Mitsubishi Heavy Industries Thermal Systems, Ltd. | Refrigeration cycle device |
CN107166478A (en) * | 2016-03-07 | 2017-09-15 | 松下知识产权经营株式会社 | Heat pump assembly |
WO2020034512A1 (en) * | 2018-08-13 | 2020-02-20 | 珠海格力电器股份有限公司 | Hot water system for air conditioner |
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WO2016094949A1 (en) * | 2014-12-17 | 2016-06-23 | HABCHI, Jason | A hide-away air-conditioning system |
CN106123260B (en) * | 2016-06-24 | 2018-12-28 | 青岛海信日立空调系统有限公司 | A kind of cold recovery energy-saving air conditioning system and control method |
JP6640695B2 (en) * | 2016-10-14 | 2020-02-05 | 株式会社コロナ | Heat pump water heater with air conditioning function |
CN108534382B (en) * | 2018-05-28 | 2020-07-03 | 陈宝山 | Self-overlapping type low-environment-temperature air source heat pump system |
JP7181453B2 (en) * | 2018-11-06 | 2022-12-01 | ダイキン工業株式会社 | hot water system |
KR20200118968A (en) * | 2019-04-09 | 2020-10-19 | 엘지전자 주식회사 | Air conditioning apparatus |
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JPH0217365A (en) * | 1988-07-06 | 1990-01-22 | Sanyo Electric Co Ltd | Air conditioning device |
JPH0289966A (en) * | 1988-09-28 | 1990-03-29 | Mitsubishi Electric Corp | Heat pump-based hot water-supplying air conditioner |
JPH08320169A (en) * | 1996-05-20 | 1996-12-03 | Sanyo Electric Co Ltd | Air conditioner |
JPWO2009098751A1 (en) | 2008-02-04 | 2011-05-26 | 三菱電機株式会社 | Air conditioning and hot water supply complex system |
US8991202B2 (en) * | 2008-03-31 | 2015-03-31 | Mitsubishi Electric Corporation | Air-conditioning hot-water supply complex system |
US20110146339A1 (en) * | 2008-10-29 | 2011-06-23 | Koji Yamashita | Air-conditioning apparatus |
WO2010109618A1 (en) * | 2009-03-26 | 2010-09-30 | 三菱電機株式会社 | Load-side relay unit and compound air conditioning/hot water supply system mounting load-side relay unit thereon |
JP5042262B2 (en) * | 2009-03-31 | 2012-10-03 | 三菱電機株式会社 | Air conditioning and hot water supply complex system |
US9310106B2 (en) * | 2009-12-28 | 2016-04-12 | Daikin Industries, Ltd. | Heat pump system |
WO2011089637A1 (en) * | 2010-01-19 | 2011-07-28 | 三菱電機株式会社 | Air conditioning-hot water supply combined system |
-
2012
- 2012-09-25 JP JP2014537856A patent/JP5893151B2/en active Active
- 2012-09-25 EP EP12885435.3A patent/EP2902726B1/en active Active
- 2012-09-25 WO PCT/JP2012/074450 patent/WO2014049673A1/en active Application Filing
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3205954A1 (en) * | 2016-02-12 | 2017-08-16 | Mitsubishi Heavy Industries Thermal Systems, Ltd. | Refrigeration cycle device |
CN107166478A (en) * | 2016-03-07 | 2017-09-15 | 松下知识产权经营株式会社 | Heat pump assembly |
WO2020034512A1 (en) * | 2018-08-13 | 2020-02-20 | 珠海格力电器股份有限公司 | Hot water system for air conditioner |
Also Published As
Publication number | Publication date |
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EP2902726B1 (en) | 2020-04-22 |
JPWO2014049673A1 (en) | 2016-08-18 |
EP2902726A4 (en) | 2016-06-08 |
JP5893151B2 (en) | 2016-03-23 |
WO2014049673A1 (en) | 2014-04-03 |
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